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[PATCH v2] WIP: Evaluate arguments of correlated SubPlans in the referencing ExprState 109+ messages / 5 participants [nested] [flat]
* [PATCH v1] WIP: Evaluate arguments of correlated SubPlans in the referencing ExprState @ 2023-02-25 21:39 Andres Freund <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Andres Freund @ 2023-02-25 21:39 UTC (permalink / raw) --- src/include/nodes/execnodes.h | 1 - src/backend/executor/execExpr.c | 81 +++++++++++++++++------------ src/backend/executor/execProcnode.c | 5 ++ src/backend/executor/nodeSubplan.c | 30 +++++------ 4 files changed, 66 insertions(+), 51 deletions(-) diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 20f4c8b35f3..437cf8b5a02 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -947,7 +947,6 @@ typedef struct SubPlanState struct PlanState *planstate; /* subselect plan's state tree */ struct PlanState *parent; /* parent plan node's state tree */ ExprState *testexpr; /* state of combining expression */ - List *args; /* states of argument expression(s) */ HeapTuple curTuple; /* copy of most recent tuple from subplan */ Datum curArray; /* most recent array from ARRAY() subplan */ /* these are used when hashing the subselect's output: */ diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index c61f23c6c18..7a9d5729b4b 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -87,6 +87,9 @@ static void ExecBuildAggTransCall(ExprState *state, AggState *aggstate, FunctionCallInfo fcinfo, AggStatePerTrans pertrans, int transno, int setno, int setoff, bool ishash, bool nullcheck); +static void ExecInitSubPlanExpr(SubPlan *subplan, + ExprState *state, + Datum *resv, bool *resnull); /* @@ -1388,7 +1391,6 @@ ExecInitExprRec(Expr *node, ExprState *state, case T_SubPlan: { SubPlan *subplan = (SubPlan *) node; - SubPlanState *sstate; /* * Real execution of a MULTIEXPR SubPlan has already been @@ -1405,19 +1407,7 @@ ExecInitExprRec(Expr *node, ExprState *state, break; } - if (!state->parent) - elog(ERROR, "SubPlan found with no parent plan"); - - sstate = ExecInitSubPlan(subplan, state->parent); - - /* add SubPlanState nodes to state->parent->subPlan */ - state->parent->subPlan = lappend(state->parent->subPlan, - sstate); - - scratch.opcode = EEOP_SUBPLAN; - scratch.d.subplan.sstate = sstate; - - ExprEvalPushStep(state, &scratch); + ExecInitSubPlanExpr(subplan, state, resv, resnull); break; } @@ -2618,29 +2608,12 @@ ExecPushExprSetupSteps(ExprState *state, ExprSetupInfo *info) foreach(lc, info->multiexpr_subplans) { SubPlan *subplan = (SubPlan *) lfirst(lc); - SubPlanState *sstate; Assert(subplan->subLinkType == MULTIEXPR_SUBLINK); - /* This should match what ExecInitExprRec does for other SubPlans: */ - - if (!state->parent) - elog(ERROR, "SubPlan found with no parent plan"); - - sstate = ExecInitSubPlan(subplan, state->parent); - - /* add SubPlanState nodes to state->parent->subPlan */ - state->parent->subPlan = lappend(state->parent->subPlan, - sstate); - - scratch.opcode = EEOP_SUBPLAN; - scratch.d.subplan.sstate = sstate; - /* The result can be ignored, but we better put it somewhere */ - scratch.resvalue = &state->resvalue; - scratch.resnull = &state->resnull; - - ExprEvalPushStep(state, &scratch); + ExecInitSubPlanExpr(subplan, state, + &state->resvalue, &state->resnull); } } @@ -4040,3 +4013,45 @@ ExecBuildParamSetEqual(TupleDesc desc, return state; } + +static void +ExecInitSubPlanExpr(SubPlan *subplan, + ExprState *state, + Datum *resv, bool *resnull) +{ + ExprEvalStep scratch = {0}; + SubPlanState *sstate; + ListCell *pvar; + ListCell *l; + EState *estate = state->parent->state; + + if (!state->parent) + elog(ERROR, "SubPlan found with no parent plan"); + + /* + * Generate steps to evaluate input arguments for the subplan. + * + * Any calculation we have to do can be done in the parent econtext, since + * the Param values don't need to have per-query lifetime. + */ + forboth(l, subplan->parParam, pvar, subplan->args) + { + int paramid = lfirst_int(l); + ParamExecData *prm = &estate->es_param_exec_vals[paramid]; + + ExecInitExprRec(lfirst(pvar), state, &prm->value, &prm->isnull); + } + + sstate = ExecInitSubPlan(subplan, state->parent); + + /* add SubPlanState nodes to state->parent->subPlan */ + state->parent->subPlan = lappend(state->parent->subPlan, + sstate); + + scratch.opcode = EEOP_SUBPLAN; + scratch.resvalue = resv; + scratch.resnull = resnull; + scratch.d.subplan.sstate = sstate; + + ExprEvalPushStep(state, &scratch); +} diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c index 4d288bc8d41..f62bb28140f 100644 --- a/src/backend/executor/execProcnode.c +++ b/src/backend/executor/execProcnode.c @@ -393,6 +393,10 @@ ExecInitNode(Plan *node, EState *estate, int eflags) /* * Initialize any initPlans present in this node. The planner put them in * a separate list for us. + * + * The defining characteristic of initplans is that they don't have + * arguments, so we don't need to evaluate them (in contrast to + * ExecInitSubPlanExpr()). */ subps = NIL; foreach(l, node->initPlan) @@ -401,6 +405,7 @@ ExecInitNode(Plan *node, EState *estate, int eflags) SubPlanState *sstate; Assert(IsA(subplan, SubPlan)); + Assert(subplan->args == NIL); sstate = ExecInitSubPlan(subplan, result); subps = lappend(subps, sstate); } diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c index c136f75ac24..3458ac007cd 100644 --- a/src/backend/executor/nodeSubplan.c +++ b/src/backend/executor/nodeSubplan.c @@ -107,7 +107,7 @@ ExecHashSubPlan(SubPlanState *node, TupleTableSlot *slot; /* Shouldn't have any direct correlation Vars */ - if (subplan->parParam != NIL || node->args != NIL) + if (subplan->parParam != NIL || subplan->args != NIL) elog(ERROR, "hashed subplan with direct correlation not supported"); /* @@ -231,7 +231,6 @@ ExecScanSubPlan(SubPlanState *node, TupleTableSlot *slot; Datum result; bool found = false; /* true if got at least one subplan tuple */ - ListCell *pvar; ListCell *l; ArrayBuildStateAny *astate = NULL; @@ -248,26 +247,20 @@ ExecScanSubPlan(SubPlanState *node, oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory); /* - * Set Params of this plan from parent plan correlation values. (Any - * calculation we have to do is done in the parent econtext, since the - * Param values don't need to have per-query lifetime.) + * We rely on the caller to evaluate plan correlation values, if + * necessary. However we still need to record the fact that the values + * (might have) changed, otherwise the ExecReScan() below won't know that + * nodes need to be rescanned. */ - Assert(list_length(subplan->parParam) == list_length(node->args)); - - forboth(l, subplan->parParam, pvar, node->args) + Assert(list_length(subplan->parParam) == list_length(subplan->args)); + foreach(l, subplan->parParam) { int paramid = lfirst_int(l); - ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); - prm->value = ExecEvalExprSwitchContext((ExprState *) lfirst(pvar), - econtext, - &(prm->isnull)); planstate->chgParam = bms_add_member(planstate->chgParam, paramid); } - /* - * Now that we've set up its parameters, we can reset the subplan. - */ + /* with that done, we can reset the subplan */ ExecReScan(planstate); /* @@ -817,6 +810,10 @@ slotNoNulls(TupleTableSlot *slot) * as well as regular SubPlans. Note that we don't link the SubPlan into * the parent's subPlan list, because that shouldn't happen for InitPlans. * Instead, ExecInitExpr() does that one part. + * + * We also rely on ExecInitExpr(), more precisely ExecInitSubPlanExpr(), to + * evaluate input parameters, as that allows them to be evaluated as part of + * the expression referencing the SubPlan. * ---------------------------------------------------------------- */ SubPlanState * @@ -844,7 +841,6 @@ ExecInitSubPlan(SubPlan *subplan, PlanState *parent) /* Initialize subexpressions */ sstate->testexpr = ExecInitExpr((Expr *) subplan->testexpr, parent); - sstate->args = ExecInitExprList(subplan->args, parent); /* * initialize my state @@ -1107,7 +1103,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) elog(ERROR, "ANY/ALL subselect unsupported as initplan"); if (subLinkType == CTE_SUBLINK) elog(ERROR, "CTE subplans should not be executed via ExecSetParamPlan"); - if (subplan->parParam || node->args) + if (subplan->parParam || subplan->args) elog(ERROR, "correlated subplans should not be executed via ExecSetParamPlan"); /* -- 2.38.0 --6ir4gcdcv6d4j3qy-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2] WIP: Evaluate arguments of correlated SubPlans in the referencing ExprState @ 2023-02-25 21:39 Andres Freund <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Andres Freund @ 2023-02-25 21:39 UTC (permalink / raw) --- src/include/executor/execExpr.h | 6 +- src/include/nodes/execnodes.h | 1 - src/backend/executor/execExpr.c | 93 +++++++++++++++++---------- src/backend/executor/execExprInterp.c | 22 +++++++ src/backend/executor/execProcnode.c | 5 ++ src/backend/executor/nodeSubplan.c | 30 ++++----- src/backend/jit/llvm/llvmjit_expr.c | 6 ++ src/backend/jit/llvm/llvmjit_types.c | 1 + 8 files changed, 112 insertions(+), 52 deletions(-) diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h index 06c3adc0a19..ca2b7306cd0 100644 --- a/src/include/executor/execExpr.h +++ b/src/include/executor/execExpr.h @@ -158,6 +158,8 @@ typedef enum ExprEvalOp EEOP_PARAM_EXEC, EEOP_PARAM_EXTERN, EEOP_PARAM_CALLBACK, + /* set PARAM_EXEC value */ + EEOP_PARAM_SET, /* return CaseTestExpr value */ EEOP_CASE_TESTVAL, @@ -374,7 +376,7 @@ typedef struct ExprEvalStep ExprEvalRowtypeCache rowcache; } nulltest_row; - /* for EEOP_PARAM_EXEC/EXTERN */ + /* for EEOP_PARAM_EXEC/EXTERN and EEOP_PARAM_SET */ struct { int paramid; /* numeric ID for parameter */ @@ -738,6 +740,8 @@ extern void ExecEvalParamExec(ExprState *state, ExprEvalStep *op, ExprContext *econtext); extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op, ExprContext *econtext); +extern void ExecEvalParamSet(ExprState *state, ExprEvalStep *op, + ExprContext *econtext); extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op); extern void ExecEvalNextValueExpr(ExprState *state, ExprEvalStep *op); extern void ExecEvalRowNull(ExprState *state, ExprEvalStep *op, diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index e7eb1e666ff..16e95e4cb48 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -947,7 +947,6 @@ typedef struct SubPlanState struct PlanState *planstate; /* subselect plan's state tree */ struct PlanState *parent; /* parent plan node's state tree */ ExprState *testexpr; /* state of combining expression */ - List *args; /* states of argument expression(s) */ HeapTuple curTuple; /* copy of most recent tuple from subplan */ Datum curArray; /* most recent array from ARRAY() subplan */ /* these are used when hashing the subselect's output: */ diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index c61f23c6c18..002f2a0091f 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -87,6 +87,9 @@ static void ExecBuildAggTransCall(ExprState *state, AggState *aggstate, FunctionCallInfo fcinfo, AggStatePerTrans pertrans, int transno, int setno, int setoff, bool ishash, bool nullcheck); +static void ExecInitSubPlanExpr(SubPlan *subplan, + ExprState *state, + Datum *resv, bool *resnull); /* @@ -1388,7 +1391,6 @@ ExecInitExprRec(Expr *node, ExprState *state, case T_SubPlan: { SubPlan *subplan = (SubPlan *) node; - SubPlanState *sstate; /* * Real execution of a MULTIEXPR SubPlan has already been @@ -1405,19 +1407,7 @@ ExecInitExprRec(Expr *node, ExprState *state, break; } - if (!state->parent) - elog(ERROR, "SubPlan found with no parent plan"); - - sstate = ExecInitSubPlan(subplan, state->parent); - - /* add SubPlanState nodes to state->parent->subPlan */ - state->parent->subPlan = lappend(state->parent->subPlan, - sstate); - - scratch.opcode = EEOP_SUBPLAN; - scratch.d.subplan.sstate = sstate; - - ExprEvalPushStep(state, &scratch); + ExecInitSubPlanExpr(subplan, state, resv, resnull); break; } @@ -2618,29 +2608,12 @@ ExecPushExprSetupSteps(ExprState *state, ExprSetupInfo *info) foreach(lc, info->multiexpr_subplans) { SubPlan *subplan = (SubPlan *) lfirst(lc); - SubPlanState *sstate; Assert(subplan->subLinkType == MULTIEXPR_SUBLINK); - /* This should match what ExecInitExprRec does for other SubPlans: */ - - if (!state->parent) - elog(ERROR, "SubPlan found with no parent plan"); - - sstate = ExecInitSubPlan(subplan, state->parent); - - /* add SubPlanState nodes to state->parent->subPlan */ - state->parent->subPlan = lappend(state->parent->subPlan, - sstate); - - scratch.opcode = EEOP_SUBPLAN; - scratch.d.subplan.sstate = sstate; - /* The result can be ignored, but we better put it somewhere */ - scratch.resvalue = &state->resvalue; - scratch.resnull = &state->resnull; - - ExprEvalPushStep(state, &scratch); + ExecInitSubPlanExpr(subplan, state, + &state->resvalue, &state->resnull); } } @@ -4040,3 +4013,57 @@ ExecBuildParamSetEqual(TupleDesc desc, return state; } + +static void +ExecInitSubPlanExpr(SubPlan *subplan, + ExprState *state, + Datum *resv, bool *resnull) +{ + ExprEvalStep scratch = {0}; + SubPlanState *sstate; + ListCell *pvar; + ListCell *l; + + if (!state->parent) + elog(ERROR, "SubPlan found with no parent plan"); + + /* + * Generate steps to evaluate input arguments for the subplan. + * + * We evaluate the argument expressions into ExprState's resvalue/resnull, + * and then use PARAM_SET to update the parameter. We do that, instead of + * evaluating directly into the param, to avoid depending on the pointer + * value remaining stable / being included in the generated expression. No + * danger of conflicts with other uses of resvalue/resnull as storing and + * using the value always is in subsequent steps. + * + * Any calculation we have to do can be done in the parent econtext, since + * the Param values don't need to have per-query lifetime. + */ + forboth(l, subplan->parParam, pvar, subplan->args) + { + int paramid = lfirst_int(l); + + ExecInitExprRec(lfirst(pvar), state, + &state->resvalue, &state->resnull); + + scratch.opcode = EEOP_PARAM_SET; + scratch.d.param.paramid = paramid; + /* type isn't needed, but an old value could be confusing */ + scratch.d.param.paramtype = InvalidOid; + ExprEvalPushStep(state, &scratch); + } + + sstate = ExecInitSubPlan(subplan, state->parent); + + /* add SubPlanState nodes to state->parent->subPlan */ + state->parent->subPlan = lappend(state->parent->subPlan, + sstate); + + scratch.opcode = EEOP_SUBPLAN; + scratch.resvalue = resv; + scratch.resnull = resnull; + scratch.d.subplan.sstate = sstate; + + ExprEvalPushStep(state, &scratch); +} diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c index 19351fe34bf..3cab8a5cdae 100644 --- a/src/backend/executor/execExprInterp.c +++ b/src/backend/executor/execExprInterp.c @@ -446,6 +446,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull) &&CASE_EEOP_PARAM_EXEC, &&CASE_EEOP_PARAM_EXTERN, &&CASE_EEOP_PARAM_CALLBACK, + &&CASE_EEOP_PARAM_SET, &&CASE_EEOP_CASE_TESTVAL, &&CASE_EEOP_MAKE_READONLY, &&CASE_EEOP_IOCOERCE, @@ -1081,6 +1082,13 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull) EEO_NEXT(); } + EEO_CASE(EEOP_PARAM_SET) + { + /* out of line, unlikely to matter performancewise */ + ExecEvalParamSet(state, op, econtext); + EEO_NEXT(); + } + EEO_CASE(EEOP_CASE_TESTVAL) { /* @@ -2477,6 +2485,20 @@ ExecEvalParamExtern(ExprState *state, ExprEvalStep *op, ExprContext *econtext) errmsg("no value found for parameter %d", paramId))); } +/* + * Set value of a param (currently always PARAM_EXEC) from + * state->res{value,null}. + */ +void +ExecEvalParamSet(ExprState *state, ExprEvalStep *op, ExprContext *econtext) +{ + ParamExecData *prm; + + prm = &(econtext->ecxt_param_exec_vals[op->d.param.paramid]); + prm->value = state->resvalue; + prm->isnull = state->resnull; +} + /* * Raise error if a CURRENT OF expression is evaluated. * diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c index 4d288bc8d41..f62bb28140f 100644 --- a/src/backend/executor/execProcnode.c +++ b/src/backend/executor/execProcnode.c @@ -393,6 +393,10 @@ ExecInitNode(Plan *node, EState *estate, int eflags) /* * Initialize any initPlans present in this node. The planner put them in * a separate list for us. + * + * The defining characteristic of initplans is that they don't have + * arguments, so we don't need to evaluate them (in contrast to + * ExecInitSubPlanExpr()). */ subps = NIL; foreach(l, node->initPlan) @@ -401,6 +405,7 @@ ExecInitNode(Plan *node, EState *estate, int eflags) SubPlanState *sstate; Assert(IsA(subplan, SubPlan)); + Assert(subplan->args == NIL); sstate = ExecInitSubPlan(subplan, result); subps = lappend(subps, sstate); } diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c index c136f75ac24..3458ac007cd 100644 --- a/src/backend/executor/nodeSubplan.c +++ b/src/backend/executor/nodeSubplan.c @@ -107,7 +107,7 @@ ExecHashSubPlan(SubPlanState *node, TupleTableSlot *slot; /* Shouldn't have any direct correlation Vars */ - if (subplan->parParam != NIL || node->args != NIL) + if (subplan->parParam != NIL || subplan->args != NIL) elog(ERROR, "hashed subplan with direct correlation not supported"); /* @@ -231,7 +231,6 @@ ExecScanSubPlan(SubPlanState *node, TupleTableSlot *slot; Datum result; bool found = false; /* true if got at least one subplan tuple */ - ListCell *pvar; ListCell *l; ArrayBuildStateAny *astate = NULL; @@ -248,26 +247,20 @@ ExecScanSubPlan(SubPlanState *node, oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory); /* - * Set Params of this plan from parent plan correlation values. (Any - * calculation we have to do is done in the parent econtext, since the - * Param values don't need to have per-query lifetime.) + * We rely on the caller to evaluate plan correlation values, if + * necessary. However we still need to record the fact that the values + * (might have) changed, otherwise the ExecReScan() below won't know that + * nodes need to be rescanned. */ - Assert(list_length(subplan->parParam) == list_length(node->args)); - - forboth(l, subplan->parParam, pvar, node->args) + Assert(list_length(subplan->parParam) == list_length(subplan->args)); + foreach(l, subplan->parParam) { int paramid = lfirst_int(l); - ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]); - prm->value = ExecEvalExprSwitchContext((ExprState *) lfirst(pvar), - econtext, - &(prm->isnull)); planstate->chgParam = bms_add_member(planstate->chgParam, paramid); } - /* - * Now that we've set up its parameters, we can reset the subplan. - */ + /* with that done, we can reset the subplan */ ExecReScan(planstate); /* @@ -817,6 +810,10 @@ slotNoNulls(TupleTableSlot *slot) * as well as regular SubPlans. Note that we don't link the SubPlan into * the parent's subPlan list, because that shouldn't happen for InitPlans. * Instead, ExecInitExpr() does that one part. + * + * We also rely on ExecInitExpr(), more precisely ExecInitSubPlanExpr(), to + * evaluate input parameters, as that allows them to be evaluated as part of + * the expression referencing the SubPlan. * ---------------------------------------------------------------- */ SubPlanState * @@ -844,7 +841,6 @@ ExecInitSubPlan(SubPlan *subplan, PlanState *parent) /* Initialize subexpressions */ sstate->testexpr = ExecInitExpr((Expr *) subplan->testexpr, parent); - sstate->args = ExecInitExprList(subplan->args, parent); /* * initialize my state @@ -1107,7 +1103,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext) elog(ERROR, "ANY/ALL subselect unsupported as initplan"); if (subLinkType == CTE_SUBLINK) elog(ERROR, "CTE subplans should not be executed via ExecSetParamPlan"); - if (subplan->parParam || node->args) + if (subplan->parParam || subplan->args) elog(ERROR, "correlated subplans should not be executed via ExecSetParamPlan"); /* diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c index 1c722c79552..812f8758743 100644 --- a/src/backend/jit/llvm/llvmjit_expr.c +++ b/src/backend/jit/llvm/llvmjit_expr.c @@ -1094,6 +1094,12 @@ llvm_compile_expr(ExprState *state) break; } + case EEOP_PARAM_SET: + build_EvalXFunc(b, mod, "ExecEvalParamSet", + v_state, op, v_econtext); + LLVMBuildBr(b, opblocks[opno + 1]); + break; + case EEOP_SBSREF_SUBSCRIPTS: { int jumpdone = op->d.sbsref_subscript.jumpdone; diff --git a/src/backend/jit/llvm/llvmjit_types.c b/src/backend/jit/llvm/llvmjit_types.c index 876fb640294..0b1df3afe00 100644 --- a/src/backend/jit/llvm/llvmjit_types.c +++ b/src/backend/jit/llvm/llvmjit_types.c @@ -123,6 +123,7 @@ void *referenced_functions[] = ExecEvalNextValueExpr, ExecEvalParamExec, ExecEvalParamExtern, + ExecEvalParamSet, ExecEvalRow, ExecEvalRowNotNull, ExecEvalRowNull, -- 2.37.1.188.g71a8fab31b --2fo66m5ddj2bowyf-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/3] Remove unnecessary volatile qualifiers. @ 2026-02-18 16:31 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-02-18 16:31 UTC (permalink / raw) --- src/backend/replication/syncrep.c | 19 ++++++++----------- src/backend/storage/ipc/procsignal.c | 4 ++-- src/backend/storage/lmgr/lock.c | 2 +- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 5 files changed, 14 insertions(+), 17 deletions(-) diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index 7ea6001e9ad..045fd35786a 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -473,7 +473,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -548,19 +547,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -767,8 +766,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -905,7 +903,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -920,7 +917,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 5d33559926a..97791f979ef 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -283,7 +283,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -394,7 +394,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index e1168ad3837..718de1b5e98 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -309,7 +309,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; /* diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 579e5933d28..a1ec13d66b9 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -36,7 +36,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -256,7 +256,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index 368e4f3f234..14972f7e7cd 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -50,7 +50,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --J5cpktPts8HkLShw Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v1-0002-Remove-SpinLockFree-and-S_LOCK_FREE.patch ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2] Convert `vacuum_index_cleanup` and GiST's `buffering` reloptions to ternary type @ 2026-05-10 10:23 Nikolay Shaplov <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nikolay Shaplov @ 2026-05-10 10:23 UTC (permalink / raw) `vacuum_index_cleanup` and GiST's `buffering` reloptions behave almost like ternary options; the only difference is that their third "unset" state can be set explicitly, using keyword "auto". This patch extends ternary option definition with `unset_alias` value, that will allow users to explicitly set option to "third value" Both `vacuum_index_cleanup` and `buffering` have been `boolean` in the past, so this patch returns them back to their original design: `boolean` with additional `auto` value. Author: Nikolay Shaplov <[email protected]> Discussion: https://postgr.es/m/20b95759-b5d6-4d46-9ab5-3ca54a9b58be%40nataraj.su --- src/backend/access/common/reloptions.c | 111 +++++++++--------- src/backend/access/gist/gistbuild.c | 4 +- src/backend/commands/vacuum.c | 11 +- src/include/access/gist_private.h | 10 +- src/include/access/reloptions.h | 11 +- src/include/utils/rel.h | 10 +- src/test/modules/dummy_index_am/README | 3 +- .../modules/dummy_index_am/dummy_index_am.c | 11 +- .../dummy_index_am/expected/reloptions.out | 27 +++-- .../modules/dummy_index_am/sql/reloptions.sql | 7 ++ src/test/regress/expected/gist.out | 2 +- src/test/regress/expected/reloptions.out | 18 +++ src/test/regress/sql/reloptions.sql | 10 ++ 13 files changed, 139 insertions(+), 96 deletions(-) diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c index 3e832c3797e..7094016a9cc 100644 --- a/src/backend/access/common/reloptions.c +++ b/src/backend/access/common/reloptions.c @@ -174,7 +174,29 @@ static relopt_ternary ternaryRelOpts[] = "Enables vacuum to truncate empty pages at the end of this table", RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, ShareUpdateExclusiveLock - } + }, + NULL, + PG_TERNARY_UNSET + }, + { + { + "vacuum_index_cleanup", + "Controls index vacuuming and index cleanup", + RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + ShareUpdateExclusiveLock + }, + "auto", + PG_TERNARY_UNSET + }, + { + { + "buffering", + "Enables buffering build for this GiST index", + RELOPT_KIND_GIST, + AccessExclusiveLock + }, + "auto", + PG_TERNARY_UNSET }, /* list terminator */ { @@ -515,30 +537,6 @@ static relopt_real realRelOpts[] = {{NULL}} }; -/* values from StdRdOptIndexCleanup */ -static relopt_enum_elt_def StdRdOptIndexCleanupValues[] = -{ - {"auto", STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO}, - {"on", STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON}, - {"off", STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF}, - {"true", STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON}, - {"false", STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF}, - {"yes", STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON}, - {"no", STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF}, - {"1", STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON}, - {"0", STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF}, - {(const char *) NULL} /* list terminator */ -}; - -/* values from GistOptBufferingMode */ -static relopt_enum_elt_def gistBufferingOptValues[] = -{ - {"auto", GIST_OPTION_BUFFERING_AUTO}, - {"on", GIST_OPTION_BUFFERING_ON}, - {"off", GIST_OPTION_BUFFERING_OFF}, - {(const char *) NULL} /* list terminator */ -}; - /* values from ViewOptCheckOption */ static relopt_enum_elt_def viewCheckOptValues[] = { @@ -550,28 +548,6 @@ static relopt_enum_elt_def viewCheckOptValues[] = static relopt_enum enumRelOpts[] = { - { - { - "vacuum_index_cleanup", - "Controls index vacuuming and index cleanup", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, - ShareUpdateExclusiveLock - }, - StdRdOptIndexCleanupValues, - STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO, - gettext_noop("Valid values are \"on\", \"off\", and \"auto\".") - }, - { - { - "buffering", - "Enables buffering build for this GiST index", - RELOPT_KIND_GIST, - AccessExclusiveLock - }, - gistBufferingOptValues, - GIST_OPTION_BUFFERING_AUTO, - gettext_noop("Valid values are \"on\", \"off\", and \"auto\".") - }, { { "check_option", @@ -939,12 +915,14 @@ add_local_bool_reloption(local_relopts *relopts, const char *name, */ static relopt_ternary * init_ternary_reloption(uint32 kinds, const char *name, const char *desc, - LOCKMODE lockmode) + pg_ternary default_val, const char* unset_alias, LOCKMODE lockmode) { relopt_ternary *newoption; newoption = (relopt_ternary *) allocate_reloption(kinds, RELOPT_TYPE_TERNARY, name, desc, lockmode); + newoption->default_val = default_val; + newoption->unset_alias = unset_alias; return newoption; } @@ -955,12 +933,12 @@ init_ternary_reloption(uint32 kinds, const char *name, const char *desc, */ void add_ternary_reloption(uint32 kinds, const char *name, const char *desc, - LOCKMODE lockmode) + pg_ternary default_val, const char* unset_alias, LOCKMODE lockmode) { relopt_ternary *newoption; - newoption = - init_ternary_reloption(kinds, name, desc, lockmode); + newoption = init_ternary_reloption(kinds, name, desc, default_val, + unset_alias, lockmode); add_reloption((relopt_gen *) newoption); } @@ -973,12 +951,13 @@ add_ternary_reloption(uint32 kinds, const char *name, const char *desc, */ void add_local_ternary_reloption(local_relopts *relopts, const char *name, - const char *desc, int offset) + const char *desc, pg_ternary default_val, + const char* unset_alias, int offset) { relopt_ternary *newoption; - newoption = - init_ternary_reloption(RELOPT_KIND_LOCAL, name, desc, 0); + newoption = init_ternary_reloption(RELOPT_KIND_LOCAL, name, desc, + default_val, unset_alias, 0); add_local_reloption(relopts, (relopt_gen *) newoption, offset); } @@ -1719,15 +1698,35 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len, case RELOPT_TYPE_TERNARY: { bool b; + relopt_ternary *opt = (relopt_ternary *) option->gen; parsed = parse_bool(value, &b); option->ternary_val = b ? PG_TERNARY_TRUE : PG_TERNARY_FALSE; - if (validate && !parsed) + + /* If no "unset alias" set, this option behaves almost like + * boolean, so report error accordingly */ + if (!opt->unset_alias && validate && !parsed) ereport(ERROR, errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid value for boolean option \"%s\": %s", option->gen->name, value)); + + if (!parsed && opt->unset_alias) + { + if (pg_strcasecmp(value, opt->unset_alias) == 0) + { + option->ternary_val = PG_TERNARY_UNSET; + parsed = true; + } + } + if (validate && !parsed) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid value for option \"%s\": %s", + option->gen->name, value), + errdetail("Valid values are \"on\", \"off\", and \"%s\".", + opt->unset_alias))); } break; case RELOPT_TYPE_INT: @@ -2020,7 +2019,7 @@ default_reloptions(Datum reloptions, bool validate, relopt_kind kind) offsetof(StdRdOptions, user_catalog_table)}, {"parallel_workers", RELOPT_TYPE_INT, offsetof(StdRdOptions, parallel_workers)}, - {"vacuum_index_cleanup", RELOPT_TYPE_ENUM, + {"vacuum_index_cleanup", RELOPT_TYPE_TERNARY, offsetof(StdRdOptions, vacuum_index_cleanup)}, {"vacuum_truncate", RELOPT_TYPE_TERNARY, offsetof(StdRdOptions, vacuum_truncate)}, diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c index 7f57c787f4c..4031a07de0e 100644 --- a/src/backend/access/gist/gistbuild.c +++ b/src/backend/access/gist/gistbuild.c @@ -213,9 +213,9 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo) */ if (options) { - if (options->buffering_mode == GIST_OPTION_BUFFERING_ON) + if (options->buffering_mode == PG_TERNARY_TRUE) buildstate.buildMode = GIST_BUFFERING_STATS; - else if (options->buffering_mode == GIST_OPTION_BUFFERING_OFF) + else if (options->buffering_mode == PG_TERNARY_FALSE) buildstate.buildMode = GIST_BUFFERING_DISABLED; else /* must be "auto" */ buildstate.buildMode = GIST_BUFFERING_AUTO; diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index a4abb29cf64..08bb3ad6c6a 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -2188,22 +2188,21 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params, */ if (params.index_cleanup == VACOPTVALUE_UNSPECIFIED) { - StdRdOptIndexCleanup vacuum_index_cleanup; + pg_ternary vacuum_index_cleanup; if (rel->rd_options == NULL) - vacuum_index_cleanup = STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO; + vacuum_index_cleanup = PG_TERNARY_UNSET; else vacuum_index_cleanup = ((StdRdOptions *) rel->rd_options)->vacuum_index_cleanup; - if (vacuum_index_cleanup == STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO) + if (vacuum_index_cleanup == PG_TERNARY_UNSET) params.index_cleanup = VACOPTVALUE_AUTO; - else if (vacuum_index_cleanup == STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON) + else if (vacuum_index_cleanup == PG_TERNARY_TRUE) params.index_cleanup = VACOPTVALUE_ENABLED; else { - Assert(vacuum_index_cleanup == - STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF); + Assert(vacuum_index_cleanup == PG_TERNARY_FALSE); params.index_cleanup = VACOPTVALUE_DISABLED; } } diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h index 44514f1cb8d..4307b8126a6 100644 --- a/src/include/access/gist_private.h +++ b/src/include/access/gist_private.h @@ -380,14 +380,6 @@ typedef struct GISTBuildBuffers int rootlevel; } GISTBuildBuffers; -/* GiSTOptions->buffering_mode values */ -typedef enum GistOptBufferingMode -{ - GIST_OPTION_BUFFERING_AUTO, - GIST_OPTION_BUFFERING_ON, - GIST_OPTION_BUFFERING_OFF, -} GistOptBufferingMode; - /* * Storage type for GiST's reloptions */ @@ -395,7 +387,7 @@ typedef struct GiSTOptions { int32 vl_len_; /* varlena header (do not touch directly!) */ int fillfactor; /* page fill factor in percent (0..100) */ - GistOptBufferingMode buffering_mode; /* buffering build mode */ + pg_ternary buffering_mode; /* buffering build mode */ } GiSTOptions; /* gist.c */ diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h index e8cb7f7a627..1c5ea85e76d 100644 --- a/src/include/access/reloptions.h +++ b/src/include/access/reloptions.h @@ -98,7 +98,8 @@ typedef struct relopt_bool typedef struct relopt_ternary { relopt_gen gen; - /* ternaries have no default_val: otherwise they'd just be bools */ + const char *unset_alias; /* word that will be treated as unset value */ + int default_val; } relopt_ternary; typedef struct relopt_int @@ -190,7 +191,8 @@ extern relopt_kind add_reloption_kind(void); extern void add_bool_reloption(uint32 kinds, const char *name, const char *desc, bool default_val, LOCKMODE lockmode); extern void add_ternary_reloption(uint32 kinds, const char *name, - const char *desc, LOCKMODE lockmode); + const char *desc, pg_ternary default_val, + const char* unset_alias, LOCKMODE lockmode); extern void add_int_reloption(uint32 kinds, const char *name, const char *desc, int default_val, int min_val, int max_val, LOCKMODE lockmode); @@ -211,8 +213,9 @@ extern void add_local_bool_reloption(local_relopts *relopts, const char *name, const char *desc, bool default_val, int offset); extern void add_local_ternary_reloption(local_relopts *relopts, - const char *name, const char *desc, - int offset); + const char *name, const char *desc, + pg_ternary default_val, const char* unset_alias, + int offset); extern void add_local_int_reloption(local_relopts *relopts, const char *name, const char *desc, int default_val, int min_val, int max_val, int offset); diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h index cd1e92f2302..15b5bf39705 100644 --- a/src/include/utils/rel.h +++ b/src/include/utils/rel.h @@ -332,14 +332,6 @@ typedef struct AutoVacOpts float8 analyze_scale_factor; } AutoVacOpts; -/* StdRdOptions->vacuum_index_cleanup values */ -typedef enum StdRdOptIndexCleanup -{ - STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO = 0, - STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF, - STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON, -} StdRdOptIndexCleanup; - typedef struct StdRdOptions { int32 vl_len_; /* varlena header (do not touch directly!) */ @@ -348,7 +340,7 @@ typedef struct StdRdOptions AutoVacOpts autovacuum; /* autovacuum-related options */ bool user_catalog_table; /* use as an additional catalog relation */ int parallel_workers; /* max number of parallel workers */ - StdRdOptIndexCleanup vacuum_index_cleanup; /* controls index vacuuming */ + pg_ternary vacuum_index_cleanup; /* controls index vacuuming */ pg_ternary vacuum_truncate; /* enables vacuum to truncate a relation */ /* diff --git a/src/test/modules/dummy_index_am/README b/src/test/modules/dummy_index_am/README index 604d823c2e4..d80aff0db19 100644 --- a/src/test/modules/dummy_index_am/README +++ b/src/test/modules/dummy_index_am/README @@ -5,7 +5,8 @@ Dummy index AM is a module for testing any facility usable by an index access method, whose code is kept a maximum simple. This includes tests for all relation option types: -- boolean & ternary +- boolean +- ternary - enum - integer - real diff --git a/src/test/modules/dummy_index_am/dummy_index_am.c b/src/test/modules/dummy_index_am/dummy_index_am.c index 31f8d2b8161..e8f6dcac9de 100644 --- a/src/test/modules/dummy_index_am/dummy_index_am.c +++ b/src/test/modules/dummy_index_am/dummy_index_am.c @@ -41,6 +41,7 @@ typedef struct DummyIndexOptions double option_real; bool option_bool; pg_ternary option_ternary_1; + pg_ternary option_ternary_2; DummyAmEnum option_enum; int option_string_val_offset; int option_string_null_offset; @@ -104,12 +105,20 @@ create_reloptions_table(void) add_ternary_reloption(di_relopt_kind, "option_ternary_1", "One ternary option for dummy_index_am", - AccessExclusiveLock); + PG_TERNARY_UNSET, NULL, AccessExclusiveLock); di_relopt_tab[i].optname = "option_ternary_1"; di_relopt_tab[i].opttype = RELOPT_TYPE_TERNARY; di_relopt_tab[i].offset = offsetof(DummyIndexOptions, option_ternary_1); i++; + add_ternary_reloption(di_relopt_kind, "option_ternary_2", + "Second ternary option for dummy_index_am", + PG_TERNARY_TRUE, "do_not_know_yet", AccessExclusiveLock); + di_relopt_tab[i].optname = "option_ternary_2"; + di_relopt_tab[i].opttype = RELOPT_TYPE_TERNARY; + di_relopt_tab[i].offset = offsetof(DummyIndexOptions, option_ternary_2); + i++; + add_enum_reloption(di_relopt_kind, "option_enum", "Enum option for dummy_index_am", dummyAmEnumValues, diff --git a/src/test/modules/dummy_index_am/expected/reloptions.out b/src/test/modules/dummy_index_am/expected/reloptions.out index 3b06d514995..90abbe2e373 100644 --- a/src/test/modules/dummy_index_am/expected/reloptions.out +++ b/src/test/modules/dummy_index_am/expected/reloptions.out @@ -19,6 +19,7 @@ CREATE INDEX dummy_test_idx ON dummy_test_tab USING dummy_index_am (i) WITH ( option_bool = false, option_ternary_1, + option_ternary_2 = off, option_int = 5, option_real = 3.1, option_enum = 'two', @@ -33,17 +34,19 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; ------------------------ option_bool=false option_ternary_1=true + option_ternary_2=off option_int=5 option_real=3.1 option_enum=two option_string_val=null option_string_null=val -(7 rows) +(8 rows) -- ALTER INDEX .. SET ALTER INDEX dummy_test_idx SET (option_int = 10); ALTER INDEX dummy_test_idx SET (option_bool = true); ALTER INDEX dummy_test_idx SET (option_ternary_1 = false); +ALTER INDEX dummy_test_idx SET (option_ternary_2 = Do_Not_Know_YET); ALTER INDEX dummy_test_idx SET (option_real = 3.2); ALTER INDEX dummy_test_idx SET (option_string_val = 'val2'); ALTER INDEX dummy_test_idx SET (option_string_null = NULL); @@ -52,21 +55,23 @@ ALTER INDEX dummy_test_idx SET (option_enum = 'three'); ERROR: invalid value for enum option "option_enum": three DETAIL: Valid values are "one" and "two". SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; - unnest -------------------------- + unnest +---------------------------------- option_int=10 option_bool=true option_ternary_1=false + option_ternary_2=do_not_know_yet option_real=3.2 option_string_val=val2 option_string_null=null option_enum=one -(7 rows) +(8 rows) -- ALTER INDEX .. RESET ALTER INDEX dummy_test_idx RESET (option_int); ALTER INDEX dummy_test_idx RESET (option_bool); ALTER INDEX dummy_test_idx RESET (option_ternary_1); +ALTER INDEX dummy_test_idx RESET (option_ternary_2); ALTER INDEX dummy_test_idx RESET (option_real); ALTER INDEX dummy_test_idx RESET (option_enum); ALTER INDEX dummy_test_idx RESET (option_string_val); @@ -113,13 +118,21 @@ ALTER INDEX dummy_test_idx SET (option_ternary_1 = 3.4); -- error ERROR: invalid value for boolean option "option_ternary_1": 3.4 ALTER INDEX dummy_test_idx SET (option_ternary_1 = 'val4'); -- error ERROR: invalid value for boolean option "option_ternary_1": val4 +ALTER INDEX dummy_test_idx SET (option_ternary_1 = 'do_not_know_yet'); -- error. Valid for ternary2 not for ternary1 +ERROR: invalid value for boolean option "option_ternary_1": do_not_know_yet +ALTER INDEX dummy_test_idx SET (option_ternary_2 = 'do_not_know_yet'); -- ok +ALTER INDEX dummy_test_idx SET (option_ternary_2 = 'illegal_value'); -- error +ERROR: invalid value for option "option_ternary_2": illegal_value +DETAIL: Valid values are "on", "off", and "do_not_know_yet". SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; - unnest --------------------- + unnest +---------------------------------- option_ternary_1=1 -(1 row) + option_ternary_2=do_not_know_yet +(2 rows) ALTER INDEX dummy_test_idx RESET (option_ternary_1); +ALTER INDEX dummy_test_idx RESET (option_ternary_2); -- Float ALTER INDEX dummy_test_idx SET (option_real = 4); -- ok ALTER INDEX dummy_test_idx SET (option_real = true); -- error diff --git a/src/test/modules/dummy_index_am/sql/reloptions.sql b/src/test/modules/dummy_index_am/sql/reloptions.sql index 2cdff0820f6..f8b985055c1 100644 --- a/src/test/modules/dummy_index_am/sql/reloptions.sql +++ b/src/test/modules/dummy_index_am/sql/reloptions.sql @@ -19,6 +19,7 @@ CREATE INDEX dummy_test_idx ON dummy_test_tab USING dummy_index_am (i) WITH ( option_bool = false, option_ternary_1, + option_ternary_2 = off, option_int = 5, option_real = 3.1, option_enum = 'two', @@ -32,6 +33,7 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; ALTER INDEX dummy_test_idx SET (option_int = 10); ALTER INDEX dummy_test_idx SET (option_bool = true); ALTER INDEX dummy_test_idx SET (option_ternary_1 = false); +ALTER INDEX dummy_test_idx SET (option_ternary_2 = Do_Not_Know_YET); ALTER INDEX dummy_test_idx SET (option_real = 3.2); ALTER INDEX dummy_test_idx SET (option_string_val = 'val2'); ALTER INDEX dummy_test_idx SET (option_string_null = NULL); @@ -43,6 +45,7 @@ SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; ALTER INDEX dummy_test_idx RESET (option_int); ALTER INDEX dummy_test_idx RESET (option_bool); ALTER INDEX dummy_test_idx RESET (option_ternary_1); +ALTER INDEX dummy_test_idx RESET (option_ternary_2); ALTER INDEX dummy_test_idx RESET (option_real); ALTER INDEX dummy_test_idx RESET (option_enum); ALTER INDEX dummy_test_idx RESET (option_string_val); @@ -68,8 +71,12 @@ ALTER INDEX dummy_test_idx SET (option_ternary_1 = 4); -- error ALTER INDEX dummy_test_idx SET (option_ternary_1 = 1); -- ok, as true ALTER INDEX dummy_test_idx SET (option_ternary_1 = 3.4); -- error ALTER INDEX dummy_test_idx SET (option_ternary_1 = 'val4'); -- error +ALTER INDEX dummy_test_idx SET (option_ternary_1 = 'do_not_know_yet'); -- error. Valid for ternary2 not for ternary1 +ALTER INDEX dummy_test_idx SET (option_ternary_2 = 'do_not_know_yet'); -- ok +ALTER INDEX dummy_test_idx SET (option_ternary_2 = 'illegal_value'); -- error SELECT unnest(reloptions) FROM pg_class WHERE relname = 'dummy_test_idx'; ALTER INDEX dummy_test_idx RESET (option_ternary_1); +ALTER INDEX dummy_test_idx RESET (option_ternary_2); -- Float ALTER INDEX dummy_test_idx SET (option_real = 4); -- ok ALTER INDEX dummy_test_idx SET (option_real = true); -- error diff --git a/src/test/regress/expected/gist.out b/src/test/regress/expected/gist.out index c75bbb23b6e..19dc547d5f8 100644 --- a/src/test/regress/expected/gist.out +++ b/src/test/regress/expected/gist.out @@ -12,7 +12,7 @@ create index gist_pointidx4 on gist_point_tbl using gist(p) with (buffering = au drop index gist_pointidx2, gist_pointidx3, gist_pointidx4; -- Make sure bad values are refused create index gist_pointidx5 on gist_point_tbl using gist(p) with (buffering = invalid_value); -ERROR: invalid value for enum option "buffering": invalid_value +ERROR: invalid value for option "buffering": invalid_value DETAIL: Valid values are "on", "off", and "auto". create index gist_pointidx5 on gist_point_tbl using gist(p) with (fillfactor=9); ERROR: value 9 out of bounds for option "fillfactor" diff --git a/src/test/regress/expected/reloptions.out b/src/test/regress/expected/reloptions.out index e3a974f2611..6e65cd5c3da 100644 --- a/src/test/regress/expected/reloptions.out +++ b/src/test/regress/expected/reloptions.out @@ -116,6 +116,24 @@ SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; {vacuum_truncate=fals} (1 row) +-- preferred "true" alias is stored in pg_class +DROP TABLE reloptions_test; +CREATE TABLE reloptions_test(i INT) WITH (vacuum_index_cleanup=on); +SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; + reloptions +--------------------------- + {vacuum_index_cleanup=on} +(1 row) + +-- custom "third" value is available +DROP TABLE reloptions_test; +CREATE TABLE reloptions_test(i INT) WITH (vacuum_index_cleanup=auto); +SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; + reloptions +----------------------------- + {vacuum_index_cleanup=auto} +(1 row) + -- Test vacuum_truncate option DROP TABLE reloptions_test; CREATE TEMP TABLE reloptions_test(i INT NOT NULL, j text) diff --git a/src/test/regress/sql/reloptions.sql b/src/test/regress/sql/reloptions.sql index 680c8bf8614..c99673db9ec 100644 --- a/src/test/regress/sql/reloptions.sql +++ b/src/test/regress/sql/reloptions.sql @@ -70,6 +70,16 @@ DROP TABLE reloptions_test; CREATE TABLE reloptions_test(i INT) WITH (vacuum_truncate=FaLS); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; +-- preferred "true" alias is stored in pg_class +DROP TABLE reloptions_test; +CREATE TABLE reloptions_test(i INT) WITH (vacuum_index_cleanup=on); +SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; + +-- custom "third" value is available +DROP TABLE reloptions_test; +CREATE TABLE reloptions_test(i INT) WITH (vacuum_index_cleanup=auto); +SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; + -- Test vacuum_truncate option DROP TABLE reloptions_test; -- 2.47.3 --nextPart2058770.usQuhbGJ8B-- --nextPart3610129.QJadu78ljV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEE+sk3ebqQKlezKOi8PMbfuIHAGpgFAmoAZ2gACgkQPMbfuIHA GpirwwgAnT+MgmIE5m1ayaChqoJfg0n4gzUrk5r4Mo7FVDBt+NgYvHwsV6NCtxC4 fPuprZV17jGDQPaJ0HKFtuOmJqa3ozoTzFm4n6l/rn5x3HV6IBrPGwy3X9QV57Wk cvhTBSzgyy7GhJB20718fbgaFoUnUhI/ieQODJzPecbdUdgle6bn6gnkRiUK72Kr /Hu8qc15vuyh/GLJUINAM/m2goNVTEb6mVcZh6zoV1FZfGYvw4X5+sNO+beg8NkW 9UZUJkIr0qolAPS1zstrPHk0MG5YfL2PR54AK7wXCT2ZUQgtlks3ghvbZINMCEmO x1AFchU+EQSS4RzdiSF5NgIcJYfpsw== =Qsjj -----END PGP SIGNATURE----- --nextPart3610129.QJadu78ljV-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v1 1/1] Remove unnecessary volatile qualifiers. @ 2026-06-30 21:41 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:41 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers to pg_atomic_* variables or local variables that hold a value returned by a pg_atomic_* function. The pointer arguments for the pg_atomic_* functions are volatile-qualified, so there's no need to mark the pointer volatile. Likewise, a local variable that just holds the result of a pg_atomic_* function gains nothing from volatile. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile when they were modified inside a PG_TRY block and used afterward, but the PG_TRY was later removed. --- src/backend/access/transam/clog.c | 2 +- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 10 ++++----- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..47975ba892f 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,7 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; + PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..4acef19e563 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) { uint64 local_gen; uint64 shared_gen; - volatile uint32 flags; + uint32 flags; Assert(MyProcSignalSlot); @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --hE8tq9meMVMcgUcn-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* remove unnecessary volatile qualifiers @ 2026-06-30 21:47 Nathan Bossart <[email protected]> 2026-07-06 11:58 ` Re: remove unnecessary volatile qualifiers Heikki Linnakangas <[email protected]> 0 siblings, 1 reply; 109+ messages in thread From: Nathan Bossart @ 2026-06-30 21:47 UTC (permalink / raw) To: pgsql-hackers I looked into some of these earlier [0], but ended up leaving them alone at the time. Here is a new patch that removes all of the volatile markers in the tree that seemed obviously unnecessary to me. [0] https://postgr.es/m/aZX2oUcKf7IzHnnK%40nathan -- nathan ^ permalink raw reply [nested|flat] 109+ messages in thread
* Re: remove unnecessary volatile qualifiers 2026-06-30 21:47 remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> @ 2026-07-06 11:58 ` Heikki Linnakangas <[email protected]> 2026-07-06 15:47 ` Re: remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 0 siblings, 1 reply; 109+ messages in thread From: Heikki Linnakangas @ 2026-07-06 11:58 UTC (permalink / raw) To: Nathan Bossart <[email protected]>; pgsql-hackers On 01/07/2026 00:47, Nathan Bossart wrote: > I looked into some of these earlier [0], but ended up leaving them alone at > the time. Here is a new patch that removes all of the volatile markers in > the tree that seemed obviously unnecessary to me. Thanks! > --- a/src/backend/access/transam/clog.c > +++ b/src/backend/access/transam/clog.c > @@ -450,7 +450,7 @@ static bool > TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, > XLogRecPtr lsn, int64 pageno) > { > - volatile PROC_HDR *procglobal = ProcGlobal; > + PROC_HDR *procglobal = ProcGlobal; > PGPROC *proc = MyProc; > uint32 nextidx; > uint32 wakeidx; You might want to get rid of the local variable altogether and just refer to ProcGlobal directly.. > @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) > { > uint64 local_gen; > uint64 shared_gen; > - volatile uint32 flags; > + uint32 flags; > > Assert(MyProcSignalSlot); > Are you sure about this one? 'flags' is used in the PG_TRY/CATCH block that follows. It is modified in the PG_TRY(), here: > > /* > * To avoid an infinite loop, we must always unset the bit in > * flags. > */ > BARRIER_CLEAR_BIT(flags, type); and read later in the PG_CATCH() block. The rest looks OK to me. - Heikki ^ permalink raw reply [nested|flat] 109+ messages in thread
* Re: remove unnecessary volatile qualifiers 2026-06-30 21:47 remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 2026-07-06 11:58 ` Re: remove unnecessary volatile qualifiers Heikki Linnakangas <[email protected]> @ 2026-07-06 15:47 ` Nathan Bossart <[email protected]> 2026-07-07 16:03 ` Re: remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 0 siblings, 1 reply; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:47 UTC (permalink / raw) To: Heikki Linnakangas <[email protected]>; +Cc: pgsql-hackers On Mon, Jul 06, 2026 at 02:58:12PM +0300, Heikki Linnakangas wrote: > On 01/07/2026 00:47, Nathan Bossart wrote: >> I looked into some of these earlier [0], but ended up leaving them alone at >> the time. Here is a new patch that removes all of the volatile markers in >> the tree that seemed obviously unnecessary to me. > > Thanks! Thanks for reviewing. >> --- a/src/backend/access/transam/clog.c >> +++ b/src/backend/access/transam/clog.c >> @@ -450,7 +450,7 @@ static bool >> TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, >> XLogRecPtr lsn, int64 pageno) >> { >> - volatile PROC_HDR *procglobal = ProcGlobal; >> + PROC_HDR *procglobal = ProcGlobal; >> PGPROC *proc = MyProc; >> uint32 nextidx; >> uint32 wakeidx; > > You might want to get rid of the local variable altogether and just refer to > ProcGlobal directly.. Done. >> @@ -512,7 +512,7 @@ ProcessProcSignalBarrier(void) >> { >> uint64 local_gen; >> uint64 shared_gen; >> - volatile uint32 flags; >> + uint32 flags; >> Assert(MyProcSignalSlot); > > Are you sure about this one? 'flags' is used in the PG_TRY/CATCH block that > follows. It is modified in the PG_TRY(), here: > >> >> /* >> * To avoid an infinite loop, we must always unset the bit in >> * flags. >> */ >> BARRIER_CLEAR_BIT(flags, type); > > and read later in the PG_CATCH() block. Whoops. You are right. I reverted this part. -- nathan ^ permalink raw reply [nested|flat] 109+ messages in thread
* Re: remove unnecessary volatile qualifiers 2026-06-30 21:47 remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 2026-07-06 11:58 ` Re: remove unnecessary volatile qualifiers Heikki Linnakangas <[email protected]> 2026-07-06 15:47 ` Re: remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> @ 2026-07-07 16:03 ` Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-07 16:03 UTC (permalink / raw) To: Heikki Linnakangas <[email protected]>; +Cc: pgsql-hackers Committed. -- nathan ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
* [PATCH v2 1/1] Remove unnecessary volatile qualifiers. @ 2026-07-06 15:24 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 109+ messages in thread From: Nathan Bossart @ 2026-07-06 15:24 UTC (permalink / raw) This commit cleans up volatile qualifiers that fit the below criteria: * Accesses to shared memory protected by a spinlock or LWLock. Before commit 0709b7ee72, callers had to use volatile when accessing spinlock-protected shared memory. Since spinlock acquire/release became compiler barriers, and because LWLocks provide the same guarantee, that is no longer necessary. These either predate that change or were cargo-culted from code that did. * Pointers used only to find the address of a member. The volatile qualifier only affects accesses made by dereferencing the pointer, so it is unnecessary there. * Accesses to struct members that are marked volatile in the struct definition. There's no need to mark these pointers volatile, either. * Leftovers from removed PG_TRY blocks. These were marked volatile to protect a value that is modified inside a PG_TRY block and used afterward, but the PG_TRY has since been removed. --- src/backend/access/transam/clog.c | 7 +++--- src/backend/catalog/index.c | 2 +- src/backend/commands/async.c | 4 ++-- src/backend/replication/syncrep.c | 19 +++++++--------- src/backend/storage/ipc/procsignal.c | 8 +++---- src/backend/storage/ipc/shm_toc.c | 31 ++++++++++++--------------- src/backend/storage/lmgr/lock.c | 2 +- src/backend/storage/lmgr/proc.c | 3 +-- src/test/modules/test_shm_mq/setup.c | 4 ++-- src/test/modules/test_shm_mq/worker.c | 2 +- 10 files changed, 37 insertions(+), 45 deletions(-) diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c index 75012d4b8f0..6f7f6b86eb6 100644 --- a/src/backend/access/transam/clog.c +++ b/src/backend/access/transam/clog.c @@ -450,7 +450,6 @@ static bool TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, XLogRecPtr lsn, int64 pageno) { - volatile PROC_HDR *procglobal = ProcGlobal; PGPROC *proc = MyProc; uint32 nextidx; uint32 wakeidx; @@ -493,7 +492,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * different from ours. If another group starts to update a page in the * same bank as ours, they wait until we release the lock. */ - nextidx = pg_atomic_read_u32(&procglobal->clogGroupFirst); + nextidx = pg_atomic_read_u32(&ProcGlobal->clogGroupFirst); while (true) { @@ -524,7 +523,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, pg_atomic_write_u32(&proc->clogGroupNext, nextidx); - if (pg_atomic_compare_exchange_u32(&procglobal->clogGroupFirst, + if (pg_atomic_compare_exchange_u32(&ProcGlobal->clogGroupFirst, &nextidx, (uint32) MyProcNumber)) break; @@ -576,7 +575,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status, * At this point, any processes trying to do this would create a separate * group. */ - nextidx = pg_atomic_exchange_u32(&procglobal->clogGroupFirst, + nextidx = pg_atomic_exchange_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER); /* Remember head of list so we can perform wakeups after dropping lock. */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 9407c357f27..81bba4beac7 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -3637,7 +3637,7 @@ reindex_index(const ReindexStmt *stmt, Oid indexId, int save_sec_context; int save_nestlevel; IndexInfo *indexInfo; - volatile bool skipped_constraint = false; + bool skipped_constraint = false; PGRUsage ru0; bool progress = ((params->options & REINDEXOPT_REPORT_PROGRESS) != 0); bool set_tablespace = false; diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index eee8bc29f38..2799f989b96 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -605,7 +605,7 @@ static void CleanupListenersOnExit(void); static bool IsListeningOn(const char *channel); static void asyncQueueUnregister(void); static bool asyncQueueIsFull(void); -static bool asyncQueueAdvance(volatile QueuePosition *position, int entryLength); +static bool asyncQueueAdvance(QueuePosition *position, int entryLength); static void asyncQueueNotificationToEntry(Notification *n, AsyncQueueEntry *qe); static ListCell *asyncQueueAddEntries(ListCell *nextNotify); static double asyncQueueUsage(void); @@ -1968,7 +1968,7 @@ asyncQueueIsFull(void) * returns true, else false. */ static bool -asyncQueueAdvance(volatile QueuePosition *position, int entryLength) +asyncQueueAdvance(QueuePosition *position, int entryLength) { int64 pageno = QUEUE_POS_PAGE(*position); int offset = QUEUE_POS_OFFSET(*position); diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index e0e30579c59..d870f09e0a0 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -483,7 +483,6 @@ SyncRepInitConfig(void) void SyncRepReleaseWaiters(void) { - volatile WalSndCtlData *walsndctl = WalSndCtl; XLogRecPtr writePtr; XLogRecPtr flushPtr; XLogRecPtr applyPtr; @@ -558,19 +557,19 @@ SyncRepReleaseWaiters(void) * Set the lsn first so that when we wake backends they will release up to * this location. */ - if (walsndctl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] < writePtr) { - walsndctl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; + WalSndCtl->lsn[SYNC_REP_WAIT_WRITE] = writePtr; numwrite = SyncRepWakeQueue(false, SYNC_REP_WAIT_WRITE); } - if (walsndctl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] < flushPtr) { - walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_FLUSH] = flushPtr; numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH); } - if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) + if (WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] < applyPtr) { - walsndctl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; + WalSndCtl->lsn[SYNC_REP_WAIT_APPLY] = applyPtr; numapply = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY); } @@ -777,8 +776,7 @@ SyncRepGetCandidateStandbys(SyncRepStandbyData **standbys) n = 0; for (i = 0; i < max_wal_senders; i++) { - volatile WalSnd *walsnd; /* Use volatile pointer to prevent code - * rearrangement */ + WalSnd *walsnd; SyncRepStandbyData *stby; WalSndState state; /* not included in SyncRepStandbyData */ @@ -915,7 +913,6 @@ SyncRepGetStandbyPriority(void) static int SyncRepWakeQueue(bool all, int mode) { - volatile WalSndCtlData *walsndctl = WalSndCtl; int numprocs = 0; dlist_mutable_iter iter; @@ -930,7 +927,7 @@ SyncRepWakeQueue(bool all, int mode) /* * Assume the queue is ordered by LSN */ - if (!all && walsndctl->lsn[mode] < proc->waitLSN) + if (!all && WalSndCtl->lsn[mode] < proc->waitLSN) return numprocs; /* diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 1397f65f67b..21a77f98c1d 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -295,7 +295,7 @@ CleanupProcSignalState(int status, Datum arg) int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber) { - volatile ProcSignalSlot *slot; + ProcSignalSlot *slot; if (procNumber != INVALID_PROC_NUMBER) { @@ -380,7 +380,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = 0; i < NumProcSignalSlots; i++) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pg_atomic_fetch_or_u32(&slot->pss_barrierCheckMask, flagbit); } @@ -406,7 +406,7 @@ EmitProcSignalBarrier(ProcSignalBarrierType type) */ for (int i = NumProcSignalSlots - 1; i >= 0; i--) { - volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; + ProcSignalSlot *slot = &ProcSignal->psh_slot[i]; pid_t pid = pg_atomic_read_u32(&slot->pss_pid); if (pid != 0) @@ -670,7 +670,7 @@ ResetProcSignalBarrierBits(uint32 flags) static bool CheckProcSignal(ProcSignalReason reason) { - volatile ProcSignalSlot *slot = MyProcSignalSlot; + ProcSignalSlot *slot = MyProcSignalSlot; if (slot != NULL) { diff --git a/src/backend/storage/ipc/shm_toc.c b/src/backend/storage/ipc/shm_toc.c index 2f9fbb0a519..2217d48c3d9 100644 --- a/src/backend/storage/ipc/shm_toc.c +++ b/src/backend/storage/ipc/shm_toc.c @@ -87,7 +87,6 @@ shm_toc_attach(uint64 magic, void *address) void * shm_toc_allocate(shm_toc *toc, Size nbytes) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -103,9 +102,9 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) + allocated_bytes; @@ -117,7 +116,7 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of shared memory"))); } - vtoc->toc_allocated_bytes += nbytes; + toc->toc_allocated_bytes += nbytes; SpinLockRelease(&toc->toc_mutex); @@ -130,16 +129,15 @@ shm_toc_allocate(shm_toc *toc, Size nbytes) Size shm_toc_freespace(shm_toc *toc) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; Size toc_bytes; SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; SpinLockRelease(&toc->toc_mutex); toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry); @@ -170,7 +168,6 @@ shm_toc_freespace(shm_toc *toc) void shm_toc_insert(shm_toc *toc, uint64 key, void *address) { - volatile shm_toc *vtoc = toc; Size total_bytes; Size allocated_bytes; Size nentry; @@ -183,14 +180,14 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) SpinLockAcquire(&toc->toc_mutex); - total_bytes = vtoc->toc_total_bytes; - allocated_bytes = vtoc->toc_allocated_bytes; - nentry = vtoc->toc_nentry; + total_bytes = toc->toc_total_bytes; + allocated_bytes = toc->toc_allocated_bytes; + nentry = toc->toc_nentry; #ifdef USE_ASSERT_CHECKING /* Verify no duplicate keys */ for (Size i = 0; i < nentry; i++) - Assert(vtoc->toc_entry[i].key != key); + Assert(toc->toc_entry[i].key != key); #endif toc_bytes = offsetof(shm_toc, toc_entry) + nentry * sizeof(shm_toc_entry) @@ -208,8 +205,8 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) } Assert(offset < total_bytes); - vtoc->toc_entry[nentry].key = key; - vtoc->toc_entry[nentry].offset = offset; + toc->toc_entry[nentry].key = key; + toc->toc_entry[nentry].offset = offset; /* * By placing a write barrier after filling in the entry and before @@ -218,7 +215,7 @@ shm_toc_insert(shm_toc *toc, uint64 key, void *address) */ pg_write_barrier(); - vtoc->toc_nentry++; + toc->toc_nentry++; SpinLockRelease(&toc->toc_mutex); } diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 8d246ed5a4e..5ee80c7632e 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -312,7 +312,7 @@ typedef struct uint32 count[FAST_PATH_STRONG_LOCK_HASH_PARTITIONS]; } FastPathStrongRelationLockData; -static volatile FastPathStrongRelationLockData *FastPathStrongRelationLocks; +static FastPathStrongRelationLockData *FastPathStrongRelationLocks; static void LockManagerShmemRequest(void *arg); static void LockManagerShmemInit(void *arg); diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 7d01c981a1f..87dd289f626 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -660,8 +660,7 @@ InitAuxiliaryProcess(void) } /* Mark auxiliary proc as in use by me */ - /* use volatile pointer to prevent code rearrangement */ - ((volatile PGPROC *) auxproc)->pid = MyProcPid; + auxproc->pid = MyProcPid; SpinLockRelease(&ProcGlobal->freeProcsLock); diff --git a/src/test/modules/test_shm_mq/setup.c b/src/test/modules/test_shm_mq/setup.c index 4f40a61e3d9..991fe27a7fa 100644 --- a/src/test/modules/test_shm_mq/setup.c +++ b/src/test/modules/test_shm_mq/setup.c @@ -38,7 +38,7 @@ static worker_state *setup_background_workers(int nworkers, dsm_segment *seg); static void cleanup_background_workers(dsm_segment *seg, Datum arg); static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr); + test_shm_mq_header *hdr); static bool check_worker_status(worker_state *wstate); /* value cached, fetched from shared memory */ @@ -258,7 +258,7 @@ cleanup_background_workers(dsm_segment *seg, Datum arg) static void wait_for_workers_to_become_ready(worker_state *wstate, - volatile test_shm_mq_header *hdr) + test_shm_mq_header *hdr) { bool result = false; diff --git a/src/test/modules/test_shm_mq/worker.c b/src/test/modules/test_shm_mq/worker.c index e13c05ae5c7..0ba1cfcac47 100644 --- a/src/test/modules/test_shm_mq/worker.c +++ b/src/test/modules/test_shm_mq/worker.c @@ -52,7 +52,7 @@ test_shm_mq_main(Datum main_arg) shm_toc *toc; shm_mq_handle *inqh; shm_mq_handle *outqh; - volatile test_shm_mq_header *hdr; + test_shm_mq_header *hdr; int myworkernumber; PGPROC *registrant; -- 2.50.1 (Apple Git-155) --z39t9WErpHrlykOW-- ^ permalink raw reply [nested|flat] 109+ messages in thread
end of thread, other threads:[~2026-07-07 16:03 UTC | newest] Thread overview: 109+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2023-02-25 21:39 [PATCH v1] WIP: Evaluate arguments of correlated SubPlans in the referencing ExprState Andres Freund <[email protected]> 2023-02-25 21:39 [PATCH v2] WIP: Evaluate arguments of correlated SubPlans in the referencing ExprState Andres Freund <[email protected]> 2026-02-18 16:31 [PATCH v1 1/3] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-05-10 10:23 [PATCH v2] Convert `vacuum_index_cleanup` and GiST's `buffering` reloptions to ternary type Nikolay Shaplov <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:41 [PATCH v1 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-06-30 21:47 remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 2026-07-06 11:58 ` Re: remove unnecessary volatile qualifiers Heikki Linnakangas <[email protected]> 2026-07-06 15:47 ` Re: remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 2026-07-07 16:03 ` Re: remove unnecessary volatile qualifiers Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]> 2026-07-06 15:24 [PATCH v2 1/1] Remove unnecessary volatile qualifiers. Nathan Bossart <[email protected]>
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