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[PATCH v1 1/2] Report wait event for cost-based vacuum delay 93+ messages / 4 participants [nested] [flat]
* [PATCH v1 1/2] Report wait event for cost-based vacuum delay @ 2020-03-21 01:47 Justin Pryzby <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Justin Pryzby @ 2020-03-21 01:47 UTC (permalink / raw) --- doc/src/sgml/monitoring.sgml | 2 ++ src/backend/commands/vacuum.c | 2 ++ src/backend/postmaster/pgstat.c | 3 +++ src/include/pgstat.h | 3 ++- 4 files changed, 9 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 5bffdcce10..46c99a55b7 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1507,6 +1507,8 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser (<filename>pg_wal</filename>, archive or stream) before trying again to retrieve WAL data, at recovery. </entry> + <entry><literal>VacuumDelay</literal></entry> + <entry>Waiting in a cost-based vacuum delay point.</entry> </row> <row> <entry morerows="68"><literal>IO</literal></entry> diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index d625d17bf4..59731d687f 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -2019,7 +2019,9 @@ vacuum_delay_point(void) if (msec > VacuumCostDelay * 4) msec = VacuumCostDelay * 4; + pgstat_report_wait_start(WAIT_EVENT_VACUUM_DELAY); pg_usleep((long) (msec * 1000)); + pgstat_report_wait_end(); VacuumCostBalance = 0; diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index d29c211a76..742ec07b59 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -3824,6 +3824,9 @@ pgstat_get_wait_timeout(WaitEventTimeout w) case WAIT_EVENT_RECOVERY_RETRIEVE_RETRY_INTERVAL: event_name = "RecoveryRetrieveRetryInterval"; break; + case WAIT_EVENT_VACUUM_DELAY: + event_name = "VacuumDelay"; + break; /* no default case, so that compiler will warn */ } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 851d0a7246..4db40e23cc 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -848,7 +848,8 @@ typedef enum WAIT_EVENT_BASE_BACKUP_THROTTLE = PG_WAIT_TIMEOUT, WAIT_EVENT_PG_SLEEP, WAIT_EVENT_RECOVERY_APPLY_DELAY, - WAIT_EVENT_RECOVERY_RETRIEVE_RETRY_INTERVAL + WAIT_EVENT_RECOVERY_RETRIEVE_RETRY_INTERVAL, + WAIT_EVENT_VACUUM_DELAY, } WaitEventTimeout; /* ---------- -- 2.17.0 --9jxsPFA5p3P2qPhR Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v1-0002-vacuum-to-report-time-spent-in-cost-based-delay.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v2 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the optional pretty argument. --- src/backend/catalog/system_functions.sql | 7 +++++++ src/backend/commands/tablecmds.c | 4 ++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 5 +---- 4 files changed, 10 insertions(+), 23 deletions(-) diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 1824faab231..a6f7cdf3a36 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -692,6 +692,13 @@ LANGUAGE INTERNAL PARALLEL SAFE AS 'pg_get_constraintdef'; +CREATE OR REPLACE FUNCTION + pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false) +RETURNS TEXT +LANGUAGE INTERNAL +PARALLEL SAFE +AS 'pg_get_expr'; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index f976c0e5c7e..12c4ce08437 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), false); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 9faf340f0c6..305e3e80c41 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 96eb7baf8e0..3a0be2d4b2a 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3986,9 +3986,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8518,7 +8515,7 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.43.0 --3/nz5wg6+DYwHsLU Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v2-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v3 6/7] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the optional pretty argument. --- src/backend/catalog/system_functions.sql | 7 +++++++ src/backend/commands/tablecmds.c | 4 ++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 5 +---- src/include/catalog/pg_retired.dat | 3 ++- 5 files changed, 12 insertions(+), 24 deletions(-) diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 1824faab231..a6f7cdf3a36 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -692,6 +692,13 @@ LANGUAGE INTERNAL PARALLEL SAFE AS 'pg_get_constraintdef'; +CREATE OR REPLACE FUNCTION + pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false) +RETURNS TEXT +LANGUAGE INTERNAL +PARALLEL SAFE +AS 'pg_get_expr'; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index f976c0e5c7e..12c4ce08437 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), false); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 4f2c93f1ee2..d87b361a093 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index ffec11c5539..4304ab220ba 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3986,9 +3986,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8518,7 +8515,7 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', diff --git a/src/include/catalog/pg_retired.dat b/src/include/catalog/pg_retired.dat index 90928a9cb00..8b5f58850f6 100644 --- a/src/include/catalog/pg_retired.dat +++ b/src/include/catalog/pg_retired.dat @@ -21,6 +21,7 @@ { oid => '1573', proname => 'pg_get_ruledef' }, { oid => '1640', proname => 'pg_get_viewdef' }, { oid => '1641', proname => 'pg_get_viewdef' }, -{ oid => '1643', proname => 'pg_get_indexdef' } +{ oid => '1643', proname => 'pg_get_indexdef' }, +{ oid => '1716', proname => 'pg_get_expr' } ] -- 2.43.0 --zd8Z8rlPOcTi77n/ Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0007-Handle-pg_get_triggerdef-default-args-in-system_f.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v4 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 7 +++---- 3 files changed, 6 insertions(+), 23 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index b04b0dbd2a0..a523a512949 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17477,8 +17477,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 03550f0d80b..a70807e84ca 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2574,23 +2574,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 1d1b24a8f4c..69c1e5bb264 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3987,9 +3987,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8531,7 +8528,9 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.43.0 --eEEy3EHc57lA8spa Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v5 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 7 +++---- 3 files changed, 6 insertions(+), 23 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 0ce2e81f9c2..fad4202b1ff 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17694,8 +17694,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 1afa2531f30..972f89eafbc 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index e148b1ad8e3..f36f4625e50 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4000,9 +4000,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8595,7 +8592,9 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.52.0 --m23X5uHFNxthGTU3 Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v5-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v7 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 9 ++++----- 3 files changed, 7 insertions(+), 24 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index eec09ba1ded..73eb6322daf 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17695,8 +17695,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 2d39bce7fd7..707f83d4310 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 39139fd9e3b..855529509de 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4006,9 +4006,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8638,9 +8635,11 @@ pronargdefaults => '1', proargdefaults => '{NULL}', prosrc => 'pg_get_database_ddl' }, { oid => '2509', - descr => 'deparse an encoded expression with pretty-print option', + descr => 'deparse an encoded expression', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.52.0 --GzYugJnip6WHHvTk Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v7-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v8 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 9 ++++----- 3 files changed, 7 insertions(+), 24 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index a1845240a98..f063f744f6d 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index d83be8cf77d..e60478677e0 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 7e452aa8c27..71bd2aaf3d9 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4006,9 +4006,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8605,9 +8602,11 @@ proargmodes => '{i,v}', proargdefaults => '{NULL}', prosrc => 'pg_get_database_ddl' }, { oid => '2509', - descr => 'deparse an encoded expression with pretty-print option', + descr => 'deparse an encoded expression', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.53.0 --iWwo79nqhOvOs5kf Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v8-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v8.1 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 9 ++++----- 3 files changed, 7 insertions(+), 24 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index a1845240a98..f063f744f6d 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index d83be8cf77d..e60478677e0 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index e610a6213ec..df43469be3d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4006,9 +4006,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8605,9 +8602,11 @@ proargmodes => '{i,v}', proargdefaults => '{NULL}', prosrc => 'pg_get_database_ddl' }, { oid => '2509', - descr => 'deparse an encoded expression with pretty-print option', + descr => 'deparse an encoded expression', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.53.0 --AcCatzXgbvyipyEy Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v8.1-0006-Handle-pg_get_triggerdef-default-args-in-system.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v1 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the optional pretty argument. --- src/backend/catalog/system_functions.sql | 7 +++++++ src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 5 +---- 3 files changed, 8 insertions(+), 21 deletions(-) diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 1f89dcc7908..81d210a9c45 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -692,6 +692,13 @@ LANGUAGE INTERNAL PARALLEL SAFE AS 'pg_get_constraintdef'; +CREATE OR REPLACE FUNCTION + pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false) +RETURNS TEXT +LANGUAGE INTERNAL +PARALLEL SAFE +AS 'pg_get_expr'; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 416144c49f5..9effa02fa2e 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index a9431ea4037..10c5286bd7d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3977,9 +3977,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8502,7 +8499,7 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.51.2 --IRGsBYp1UN8d6WrT Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v1-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v2 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the optional pretty argument. --- src/backend/catalog/system_functions.sql | 7 +++++++ src/backend/commands/tablecmds.c | 4 ++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 5 +---- 4 files changed, 10 insertions(+), 23 deletions(-) diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 1824faab231..a6f7cdf3a36 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -692,6 +692,13 @@ LANGUAGE INTERNAL PARALLEL SAFE AS 'pg_get_constraintdef'; +CREATE OR REPLACE FUNCTION + pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false) +RETURNS TEXT +LANGUAGE INTERNAL +PARALLEL SAFE +AS 'pg_get_expr'; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index f976c0e5c7e..12c4ce08437 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), false); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 9faf340f0c6..305e3e80c41 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 96eb7baf8e0..3a0be2d4b2a 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3986,9 +3986,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8518,7 +8515,7 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.43.0 --3/nz5wg6+DYwHsLU Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v2-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v3 6/7] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the optional pretty argument. --- src/backend/catalog/system_functions.sql | 7 +++++++ src/backend/commands/tablecmds.c | 4 ++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 5 +---- src/include/catalog/pg_retired.dat | 3 ++- 5 files changed, 12 insertions(+), 24 deletions(-) diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 1824faab231..a6f7cdf3a36 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -692,6 +692,13 @@ LANGUAGE INTERNAL PARALLEL SAFE AS 'pg_get_constraintdef'; +CREATE OR REPLACE FUNCTION + pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false) +RETURNS TEXT +LANGUAGE INTERNAL +PARALLEL SAFE +AS 'pg_get_expr'; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index f976c0e5c7e..12c4ce08437 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), false); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 4f2c93f1ee2..d87b361a093 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index ffec11c5539..4304ab220ba 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3986,9 +3986,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8518,7 +8515,7 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', diff --git a/src/include/catalog/pg_retired.dat b/src/include/catalog/pg_retired.dat index 90928a9cb00..8b5f58850f6 100644 --- a/src/include/catalog/pg_retired.dat +++ b/src/include/catalog/pg_retired.dat @@ -21,6 +21,7 @@ { oid => '1573', proname => 'pg_get_ruledef' }, { oid => '1640', proname => 'pg_get_viewdef' }, { oid => '1641', proname => 'pg_get_viewdef' }, -{ oid => '1643', proname => 'pg_get_indexdef' } +{ oid => '1643', proname => 'pg_get_indexdef' }, +{ oid => '1716', proname => 'pg_get_expr' } ] -- 2.43.0 --zd8Z8rlPOcTi77n/ Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0007-Handle-pg_get_triggerdef-default-args-in-system_f.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v4 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 7 +++---- 3 files changed, 6 insertions(+), 23 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index b04b0dbd2a0..a523a512949 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17477,8 +17477,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 03550f0d80b..a70807e84ca 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2574,23 +2574,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 1d1b24a8f4c..69c1e5bb264 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3987,9 +3987,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8531,7 +8528,9 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.43.0 --eEEy3EHc57lA8spa Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch" ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v5 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 7 +++---- 3 files changed, 6 insertions(+), 23 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 0ce2e81f9c2..fad4202b1ff 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17694,8 +17694,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 1afa2531f30..972f89eafbc 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index e148b1ad8e3..f36f4625e50 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4000,9 +4000,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8595,7 +8592,9 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.52.0 --m23X5uHFNxthGTU3 Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v5-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v7 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 9 ++++----- 3 files changed, 7 insertions(+), 24 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index eec09ba1ded..73eb6322daf 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17695,8 +17695,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 2d39bce7fd7..707f83d4310 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 39139fd9e3b..855529509de 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4006,9 +4006,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8638,9 +8635,11 @@ pronargdefaults => '1', proargdefaults => '{NULL}', prosrc => 'pg_get_database_ddl' }, { oid => '2509', - descr => 'deparse an encoded expression with pretty-print option', + descr => 'deparse an encoded expression', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.52.0 --GzYugJnip6WHHvTk Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v7-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v8 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 9 ++++----- 3 files changed, 7 insertions(+), 24 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index a1845240a98..f063f744f6d 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index d83be8cf77d..e60478677e0 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 7e452aa8c27..71bd2aaf3d9 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4006,9 +4006,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8605,9 +8602,11 @@ proargmodes => '{i,v}', proargdefaults => '{NULL}', prosrc => 'pg_get_database_ddl' }, { oid => '2509', - descr => 'deparse an encoded expression with pretty-print option', + descr => 'deparse an encoded expression', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.53.0 --iWwo79nqhOvOs5kf Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v8-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v8.1 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use proargdefaults to handle the optional pretty argument. That also means any direct function calls now needs to set the pretty parameter. --- src/backend/commands/tablecmds.c | 5 +++-- src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 9 ++++----- 3 files changed, 7 insertions(+), 24 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index a1845240a98..f063f744f6d 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc) if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); - expr = DirectFunctionCall2(pg_get_expr, attr, - ObjectIdGetDatum(con->conrelid)); + expr = DirectFunctionCall3(pg_get_expr, attr, + ObjectIdGetDatum(con->conrelid), + BoolGetDatum(false)); return TextDatumGetCString(expr); } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index d83be8cf77d..e60478677e0 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index e610a6213ec..df43469be3d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -4006,9 +4006,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8605,9 +8602,11 @@ proargmodes => '{i,v}', proargdefaults => '{NULL}', prosrc => 'pg_get_database_ddl' }, { oid => '2509', - descr => 'deparse an encoded expression with pretty-print option', + descr => 'deparse an encoded expression', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', + proargnames => '{expr,relation,pretty}', proargdefaults => '{false}', + prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.53.0 --AcCatzXgbvyipyEy Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v8.1-0006-Handle-pg_get_triggerdef-default-args-in-system.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v1 5/6] Handle pg_get_expr default args in system_functions.sql @ 2025-12-09 19:17 Mark Wong <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw) Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the optional pretty argument. --- src/backend/catalog/system_functions.sql | 7 +++++++ src/backend/utils/adt/ruleutils.c | 17 ----------------- src/include/catalog/pg_proc.dat | 5 +---- 3 files changed, 8 insertions(+), 21 deletions(-) diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 1f89dcc7908..81d210a9c45 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -692,6 +692,13 @@ LANGUAGE INTERNAL PARALLEL SAFE AS 'pg_get_constraintdef'; +CREATE OR REPLACE FUNCTION + pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false) +RETURNS TEXT +LANGUAGE INTERNAL +PARALLEL SAFE +AS 'pg_get_expr'; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 416144c49f5..9effa02fa2e 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId, */ Datum pg_get_expr(PG_FUNCTION_ARGS) -{ - text *expr = PG_GETARG_TEXT_PP(0); - Oid relid = PG_GETARG_OID(1); - text *result; - int prettyFlags; - - prettyFlags = PRETTYFLAG_INDENT; - - result = pg_get_expr_worker(expr, relid, prettyFlags); - if (result) - PG_RETURN_TEXT_P(result); - else - PG_RETURN_NULL(); -} - -Datum -pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_PP(0); Oid relid = PG_GETARG_OID(1); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index a9431ea4037..10c5286bd7d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3977,9 +3977,6 @@ { oid => '1662', descr => 'trigger description', proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_triggerdef' }, -{ oid => '1716', descr => 'deparse an encoded expression', - proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' }, { oid => '1665', descr => 'name of sequence for a serial column', proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text', proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' }, @@ -8502,7 +8499,7 @@ { oid => '2509', descr => 'deparse an encoded expression with pretty-print option', proname => 'pg_get_expr', provolatile => 's', prorettype => 'text', - proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' }, + proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' }, { oid => '2510', descr => 'get the prepared statements for this session', proname => 'pg_prepared_statement', prorows => '1000', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', -- 2.51.2 --IRGsBYp1UN8d6WrT Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v1-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH v4 1/1] remove toast reloptions @ 2026-04-07 20:30 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Nathan Bossart @ 2026-04-07 20:30 UTC (permalink / raw) --- doc/src/sgml/ref/create_table.sgml | 51 ++++++------- src/backend/access/common/reloptions.c | 49 +++++------- src/backend/catalog/toasting.c | 31 ++++---- src/backend/commands/createas.c | 13 +--- src/backend/commands/repack.c | 15 +--- src/backend/commands/tablecmds.c | 19 +---- src/backend/commands/vacuum.c | 14 +--- src/backend/postmaster/autovacuum.c | 48 +++++------- src/backend/tcop/utility.c | 19 +---- src/bin/pg_upgrade/check.c | 75 +++++++++++++++++++ src/include/access/reloptions.h | 24 +++--- src/include/catalog/toasting.h | 6 +- .../injection_points/expected/vacuum.out | 24 +++--- .../modules/injection_points/sql/vacuum.sql | 20 ++--- src/test/regress/expected/alter_table.out | 9 --- src/test/regress/expected/reloptions.out | 56 ++------------ src/test/regress/expected/vacuum.out | 8 -- src/test/regress/sql/alter_table.sql | 4 - src/test/regress/sql/reloptions.sql | 32 +------- src/test/regress/sql/vacuum.sql | 8 -- 20 files changed, 199 insertions(+), 326 deletions(-) diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index e342585c7f0..b8d2a657d10 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1589,14 +1589,10 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM Storage parameters for indexes are documented in <xref linkend="sql-createindex"/>. The storage parameters currently - available for tables are listed below. For many of these parameters, as - shown, there is an additional parameter with the same name prefixed with - <literal>toast.</literal>, which controls the behavior of the + available for tables are listed below. Unless otherwise noted, a table's + parameter value also controls the behavior of the table's secondary <acronym>TOAST</acronym> table, if any (see <xref linkend="storage-toast"/> for more information about TOAST). - If a table parameter value is set and the - equivalent <literal>toast.</literal> parameter is not, the TOAST table - will use the table's parameter value. Specifying these parameters for partitioned tables is not supported, but you may specify them for individual leaf partitions. </para> @@ -1622,7 +1618,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM updates</link> more likely. For a table whose entries are never updated, complete packing is the best choice, but in heavily updated tables smaller fillfactors are - appropriate. This parameter cannot be set for TOAST tables. + appropriate. This parameter does not affect the table's secondary TOAST + table. </para> </listitem> </varlistentry> @@ -1648,7 +1645,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM Note that the default setting is often close to optimal, and it is possible that setting this parameter could have negative effects in some cases. - This parameter cannot be set for TOAST tables. + This parameter does not affect the table's secondary TOAST table. </para> </listitem> </varlistentry> @@ -1671,7 +1668,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-enabled" xreflabel="autovacuum_enabled"> - <term><literal>autovacuum_enabled</literal>, <literal>toast.autovacuum_enabled</literal> (<type>boolean</type>) + <term><literal>autovacuum_enabled</literal> (<type>boolean</type>) <indexterm> <primary><varname>autovacuum_enabled</varname> storage parameter</primary> </indexterm> @@ -1696,7 +1693,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-vacuum-index-cleanup" xreflabel="vacuum_index_cleanup"> - <term><literal>vacuum_index_cleanup</literal>, <literal>toast.vacuum_index_cleanup</literal> (<type>enum</type>) + <term><literal>vacuum_index_cleanup</literal> (<type>enum</type>) <indexterm> <primary><varname>vacuum_index_cleanup</varname> storage parameter</primary> </indexterm> @@ -1722,7 +1719,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-vacuum-truncate" xreflabel="vacuum_truncate"> - <term><literal>vacuum_truncate</literal>, <literal>toast.vacuum_truncate</literal> (<type>boolean</type>) + <term><literal>vacuum_truncate</literal> (<type>boolean</type>) <indexterm> <primary><varname>vacuum_truncate</varname></primary> <secondary>storage parameter</secondary> @@ -1755,7 +1752,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-threshold" xreflabel="autovacuum_vacuum_threshold"> - <term><literal>autovacuum_vacuum_threshold</literal>, <literal>toast.autovacuum_vacuum_threshold</literal> (<type>integer</type>) + <term><literal>autovacuum_vacuum_threshold</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_vacuum_threshold</varname></primary> <secondary>storage parameter</secondary> @@ -1770,7 +1767,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-max-threshold" xreflabel="autovacuum_vacuum_max_threshold"> - <term><literal>autovacuum_vacuum_max_threshold</literal>, <literal>toast.autovacuum_vacuum_max_threshold</literal> (<type>integer</type>) + <term><literal>autovacuum_vacuum_max_threshold</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_vacuum_max_threshold</varname></primary> <secondary>storage parameter</secondary> @@ -1785,7 +1782,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-scale-factor" xreflabel="autovacuum_vacuum_scale_factor"> - <term><literal>autovacuum_vacuum_scale_factor</literal>, <literal>toast.autovacuum_vacuum_scale_factor</literal> (<type>floating point</type>) + <term><literal>autovacuum_vacuum_scale_factor</literal> (<type>floating point</type>) <indexterm> <primary><varname>autovacuum_vacuum_scale_factor</varname> </primary> <secondary>storage parameter</secondary> @@ -1800,7 +1797,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-insert-threshold" xreflabel="autovacuum_vacuum_insert_threshold"> - <term><literal>autovacuum_vacuum_insert_threshold</literal>, <literal>toast.autovacuum_vacuum_insert_threshold</literal> (<type>integer</type>) + <term><literal>autovacuum_vacuum_insert_threshold</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_vacuum_insert_threshold</varname></primary> <secondary>storage parameter</secondary> @@ -1815,7 +1812,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-insert-scale-factor" xreflabel="autovacuum_vacuum_insert_scale_factor"> - <term><literal>autovacuum_vacuum_insert_scale_factor</literal>, <literal>toast.autovacuum_vacuum_insert_scale_factor</literal> (<type>floating point</type>) + <term><literal>autovacuum_vacuum_insert_scale_factor</literal> (<type>floating point</type>) <indexterm> <primary><varname>autovacuum_vacuum_insert_scale_factor</varname> </primary> <secondary>storage parameter</secondary> @@ -1860,7 +1857,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-cost-delay" xreflabel="autovacuum_vacuum_cost_delay"> - <term><literal>autovacuum_vacuum_cost_delay</literal>, <literal>toast.autovacuum_vacuum_cost_delay</literal> (<type>floating point</type>) + <term><literal>autovacuum_vacuum_cost_delay</literal> (<type>floating point</type>) <indexterm> <primary><varname>autovacuum_vacuum_cost_delay</varname></primary> <secondary>storage parameter</secondary> @@ -1875,7 +1872,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-vacuum-cost-limit" xreflabel="autovacuum_vacuum_cost_limit"> - <term><literal>autovacuum_vacuum_cost_limit</literal>, <literal>toast.autovacuum_vacuum_cost_limit</literal> (<type>integer</type>) + <term><literal>autovacuum_vacuum_cost_limit</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_vacuum_cost_limit</varname></primary> <secondary>storage parameter</secondary> @@ -1890,7 +1887,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-freeze-min-age" xreflabel="autovacuum_freeze_min_age"> - <term><literal>autovacuum_freeze_min_age</literal>, <literal>toast.autovacuum_freeze_min_age</literal> (<type>integer</type>) + <term><literal>autovacuum_freeze_min_age</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_freeze_min_age</varname> storage parameter</primary> </indexterm> @@ -1907,7 +1904,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-freeze-max-age" xreflabel="autovacuum_freeze_max_age"> - <term><literal>autovacuum_freeze_max_age</literal>, <literal>toast.autovacuum_freeze_max_age</literal> (<type>integer</type>) + <term><literal>autovacuum_freeze_max_age</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_freeze_max_age</varname></primary> <secondary>storage parameter</secondary> @@ -1924,7 +1921,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-freeze-table-age" xreflabel="autovacuum_freeze_table_age"> - <term><literal>autovacuum_freeze_table_age</literal>, <literal>toast.autovacuum_freeze_table_age</literal> (<type>integer</type>) + <term><literal>autovacuum_freeze_table_age</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_freeze_table_age</varname> storage parameter</primary> </indexterm> @@ -1938,7 +1935,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-multixact-freeze-min-age" xreflabel="autovacuum_multixact_freeze_min_age"> - <term><literal>autovacuum_multixact_freeze_min_age</literal>, <literal>toast.autovacuum_multixact_freeze_min_age</literal> (<type>integer</type>) + <term><literal>autovacuum_multixact_freeze_min_age</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_multixact_freeze_min_age</varname> storage parameter</primary> </indexterm> @@ -1956,7 +1953,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-multixact-freeze-max-age" xreflabel="autovacuum_multixact_freeze_max_age"> - <term><literal>autovacuum_multixact_freeze_max_age</literal>, <literal>toast.autovacuum_multixact_freeze_max_age</literal> (<type>integer</type>) + <term><literal>autovacuum_multixact_freeze_max_age</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_multixact_freeze_max_age</varname></primary> <secondary>storage parameter</secondary> @@ -1975,7 +1972,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-autovacuum-multixact-freeze-table-age" xreflabel="autovacuum_multixact_freeze_table_age"> - <term><literal>autovacuum_multixact_freeze_table_age</literal>, <literal>toast.autovacuum_multixact_freeze_table_age</literal> (<type>integer</type>) + <term><literal>autovacuum_multixact_freeze_table_age</literal> (<type>integer</type>) <indexterm> <primary><varname>autovacuum_multixact_freeze_table_age</varname> storage parameter</primary> </indexterm> @@ -1989,7 +1986,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-log-autovacuum-min-duration" xreflabel="log_autovacuum_min_duration"> - <term><literal>log_autovacuum_min_duration</literal>, <literal>toast.log_autovacuum_min_duration</literal> (<type>integer</type>) + <term><literal>log_autovacuum_min_duration</literal> (<type>integer</type>) <indexterm> <primary><varname>log_autovacuum_min_duration</varname></primary> <secondary>storage parameter</secondary> @@ -2019,7 +2016,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="reloption-vacuum-max-eager-freeze-failure-rate" xreflabel="vacuum_max_eager_freeze_failure_rate"> - <term><literal>vacuum_max_eager_freeze_failure_rate</literal>, <literal>toast.vacuum_max_eager_freeze_failure_rate</literal> (<type>floating point</type>) + <term><literal>vacuum_max_eager_freeze_failure_rate</literal> (<type>floating point</type>) <indexterm> <primary><varname>vacuum_max_eager_freeze_failure_rate</varname></primary> <secondary>storage parameter</secondary> @@ -2044,7 +2041,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM Declare the table as an additional catalog table for purposes of logical replication. See <xref linkend="logicaldecoding-capabilities"/> for details. - This parameter cannot be set for TOAST tables. + This parameter does not affect the table's secondary TOAST table. </para> </listitem> </varlistentry> diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c index 3e832c3797e..50d9805f3d8 100644 --- a/src/backend/access/common/reloptions.c +++ b/src/backend/access/common/reloptions.c @@ -111,7 +111,7 @@ static relopt_bool boolRelOpts[] = { "autovacuum_enabled", "Enables autovacuum in this relation", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, true @@ -172,7 +172,7 @@ static relopt_ternary ternaryRelOpts[] = { "vacuum_truncate", "Enables vacuum to truncate empty pages at the end of this table", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock } }, @@ -249,7 +249,7 @@ static relopt_int intRelOpts[] = { "autovacuum_vacuum_threshold", "Minimum number of tuple updates or deletes prior to vacuum", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0, INT_MAX @@ -258,7 +258,7 @@ static relopt_int intRelOpts[] = { "autovacuum_vacuum_max_threshold", "Maximum number of tuple updates or deletes prior to vacuum", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -2, -1, INT_MAX @@ -267,7 +267,7 @@ static relopt_int intRelOpts[] = { "autovacuum_vacuum_insert_threshold", "Minimum number of tuple inserts prior to vacuum, or -1 to disable insert vacuums", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -2, -1, INT_MAX @@ -285,7 +285,7 @@ static relopt_int intRelOpts[] = { "autovacuum_vacuum_cost_limit", "Vacuum cost amount available before napping, for autovacuum", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 1, 10000 @@ -294,7 +294,7 @@ static relopt_int intRelOpts[] = { "autovacuum_freeze_min_age", "Minimum age at which VACUUM should freeze a table row, for autovacuum", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0, 1000000000 @@ -303,7 +303,7 @@ static relopt_int intRelOpts[] = { "autovacuum_multixact_freeze_min_age", "Minimum multixact age at which VACUUM should freeze a row multixact's, for autovacuum", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0, 1000000000 @@ -312,7 +312,7 @@ static relopt_int intRelOpts[] = { "autovacuum_freeze_max_age", "Age at which to autovacuum a table to prevent transaction ID wraparound", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 100000, 2000000000 @@ -321,7 +321,7 @@ static relopt_int intRelOpts[] = { "autovacuum_multixact_freeze_max_age", "Multixact age at which to autovacuum a table to prevent multixact wraparound", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 10000, 2000000000 @@ -330,7 +330,7 @@ static relopt_int intRelOpts[] = { "autovacuum_freeze_table_age", "Age at which VACUUM should perform a full table sweep to freeze row versions", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0, 2000000000 }, @@ -338,7 +338,7 @@ static relopt_int intRelOpts[] = { "autovacuum_multixact_freeze_table_age", "Age of multixact at which VACUUM should perform a full table sweep to freeze row versions", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0, 2000000000 }, @@ -346,7 +346,7 @@ static relopt_int intRelOpts[] = { "log_autovacuum_min_duration", "Sets the minimum execution time above which vacuum actions by autovacuum will be logged", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, -1, INT_MAX @@ -424,7 +424,7 @@ static relopt_real realRelOpts[] = { "autovacuum_vacuum_cost_delay", "Vacuum cost delay in milliseconds, for autovacuum", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0.0, 100.0 @@ -433,7 +433,7 @@ static relopt_real realRelOpts[] = { "autovacuum_vacuum_scale_factor", "Number of tuple updates or deletes prior to vacuum as a fraction of reltuples", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0.0, 100.0 @@ -442,7 +442,7 @@ static relopt_real realRelOpts[] = { "autovacuum_vacuum_insert_scale_factor", "Number of tuple inserts prior to vacuum as a fraction of reltuples", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0.0, 100.0 @@ -460,7 +460,7 @@ static relopt_real realRelOpts[] = { "vacuum_max_eager_freeze_failure_rate", "Fraction of pages in a relation vacuum can scan and fail to freeze before disabling eager scanning.", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, -1, 0.0, 1.0 @@ -554,7 +554,7 @@ static relopt_enum enumRelOpts[] = { "vacuum_index_cleanup", "Controls index vacuuming and index cleanup", - RELOPT_KIND_HEAP | RELOPT_KIND_TOAST, + RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, StdRdOptIndexCleanupValues, @@ -2163,21 +2163,8 @@ view_reloptions(Datum reloptions, bool validate) bytea * heap_reloptions(char relkind, Datum reloptions, bool validate) { - StdRdOptions *rdopts; - switch (relkind) { - case RELKIND_TOASTVALUE: - rdopts = (StdRdOptions *) - default_reloptions(reloptions, validate, RELOPT_KIND_TOAST); - if (rdopts != NULL) - { - /* adjust default-only parameters for TOAST relations */ - rdopts->fillfactor = 100; - rdopts->autovacuum.analyze_threshold = -1; - rdopts->autovacuum.analyze_scale_factor = -1; - } - return (bytea *) rdopts; case RELKIND_RELATION: case RELKIND_MATVIEW: return default_reloptions(reloptions, validate, RELOPT_KIND_HEAP); diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c index 4aa52a4bd25..9f1f822702c 100644 --- a/src/backend/catalog/toasting.c +++ b/src/backend/catalog/toasting.c @@ -34,11 +34,11 @@ #include "utils/rel.h" #include "utils/syscache.h" -static void CheckAndCreateToastTable(Oid relOid, Datum reloptions, +static void CheckAndCreateToastTable(Oid relOid, LOCKMODE lockmode, bool check, Oid OIDOldToast); static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid, - Datum reloptions, LOCKMODE lockmode, bool check, + LOCKMODE lockmode, bool check, Oid OIDOldToast); static bool needs_toast_table(Relation rel); @@ -48,35 +48,30 @@ static bool needs_toast_table(Relation rel); * If the table needs a toast table, and doesn't already have one, * then create a toast table for it. * - * reloptions for the toast table can be passed, too. Pass (Datum) 0 - * for default reloptions. - * * We expect the caller to have verified that the relation is a table and have * already done any necessary permission checks. Callers expect this function * to end with CommandCounterIncrement if it makes any changes. */ void -AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode) +AlterTableCreateToastTable(Oid relOid, LOCKMODE lockmode) { - CheckAndCreateToastTable(relOid, reloptions, lockmode, true, InvalidOid); + CheckAndCreateToastTable(relOid, lockmode, true, InvalidOid); } void -NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode, - Oid OIDOldToast) +NewHeapCreateToastTable(Oid relOid, LOCKMODE lockmode, Oid OIDOldToast) { - CheckAndCreateToastTable(relOid, reloptions, lockmode, false, OIDOldToast); + CheckAndCreateToastTable(relOid, lockmode, false, OIDOldToast); } void -NewRelationCreateToastTable(Oid relOid, Datum reloptions) +NewRelationCreateToastTable(Oid relOid) { - CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false, - InvalidOid); + CheckAndCreateToastTable(relOid, AccessExclusiveLock, false, InvalidOid); } static void -CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode, +CheckAndCreateToastTable(Oid relOid, LOCKMODE lockmode, bool check, Oid OIDOldToast) { Relation rel; @@ -84,7 +79,7 @@ CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode, rel = table_open(relOid, lockmode); /* create_toast_table does all the work */ - (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode, + (void) create_toast_table(rel, InvalidOid, InvalidOid, lockmode, check, OIDOldToast); table_close(rel, NoLock); @@ -108,7 +103,7 @@ BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid) relName); /* create_toast_table does all the work */ - if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0, + if (!create_toast_table(rel, toastOid, toastIndexOid, AccessExclusiveLock, false, InvalidOid)) elog(ERROR, "\"%s\" does not require a toast table", relName); @@ -126,7 +121,7 @@ BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid) */ static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid, - Datum reloptions, LOCKMODE lockmode, bool check, + LOCKMODE lockmode, bool check, Oid OIDOldToast) { Oid relOid = RelationGetRelid(rel); @@ -266,7 +261,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid, shared_relation, mapped_relation, ONCOMMIT_NOOP, - reloptions, + (Datum) 0, false, true, true, diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c index 6dbb831ca89..188e167999b 100644 --- a/src/backend/commands/createas.c +++ b/src/backend/commands/createas.c @@ -84,8 +84,6 @@ create_ctas_internal(List *attrList, IntoClause *into) CreateStmt *create = makeNode(CreateStmt); bool is_matview; char relkind; - Datum toast_options; - const char *const validnsps[] = HEAP_RELOPT_NAMESPACES; ObjectAddress intoRelationAddr; /* This code supports both CREATE TABLE AS and CREATE MATERIALIZED VIEW */ @@ -120,16 +118,7 @@ create_ctas_internal(List *attrList, IntoClause *into) */ CommandCounterIncrement(); - /* parse and validate reloptions for the toast table */ - toast_options = transformRelOptions((Datum) 0, - create->options, - "toast", - validnsps, - true, false); - - (void) heap_reloptions(RELKIND_TOASTVALUE, toast_options, true); - - NewRelationCreateToastTable(intoRelationAddr.objectId, toast_options); + NewRelationCreateToastTable(intoRelationAddr.objectId); /* Create the "view" part of a materialized view. */ if (is_matview) diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index 9a199dd9bfb..3b80d331815 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -1201,20 +1201,7 @@ make_new_heap(Oid OIDOldHeap, Oid NewTableSpace, Oid NewAccessMethod, */ toastid = OldHeap->rd_rel->reltoastrelid; if (OidIsValid(toastid)) - { - /* keep the existing toast table's reloptions, if any */ - tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid)); - if (!HeapTupleIsValid(tuple)) - elog(ERROR, "cache lookup failed for relation %u", toastid); - reloptions = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, - &isNull); - if (isNull) - reloptions = (Datum) 0; - - NewHeapCreateToastTable(OIDNewHeap, reloptions, lockmode, toastid); - - ReleaseSysCache(tuple); - } + NewHeapCreateToastTable(OIDNewHeap, lockmode, toastid); table_close(OldHeap, NoLock); diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index d8d7969bf30..a254509cbb5 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -827,7 +827,6 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, ListCell *listptr; AttrNumber attnum; bool partitioned; - const char *const validnsps[] = HEAP_RELOPT_NAMESPACES; Oid ofTypeId; ObjectAddress address; LOCKMODE parentLockmode; @@ -976,7 +975,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, /* * Parse and validate reloptions, if any. */ - reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps, + reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, NULL, true, false); switch (relkind) @@ -5433,7 +5432,7 @@ ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode, tab->relkind == RELKIND_PARTITIONED_TABLE) && tab->partition_constraint == NULL) || tab->relkind == RELKIND_MATVIEW) - AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode); + AlterTableCreateToastTable(tab->relid, lockmode); } } @@ -16927,7 +16926,6 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, Datum repl_val[Natts_pg_class]; bool repl_null[Natts_pg_class]; bool repl_repl[Natts_pg_class]; - const char *const validnsps[] = HEAP_RELOPT_NAMESPACES; if (defList == NIL && operation != AT_ReplaceRelOptions) return; /* nothing to do */ @@ -16960,7 +16958,7 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, } /* Generate new proposed reloptions (text array) */ - newOptions = transformRelOptions(datum, defList, NULL, validnsps, false, + newOptions = transformRelOptions(datum, defList, NULL, NULL, false, operation == AT_ResetRelOptions); /* Validate */ @@ -17083,20 +17081,11 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, datum = (Datum) 0; } - newOptions = transformRelOptions(datum, defList, "toast", validnsps, - false, operation == AT_ResetRelOptions); - - (void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true); - memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); - if (newOptions != (Datum) 0) - repl_val[Anum_pg_class_reloptions - 1] = newOptions; - else - repl_null[Anum_pg_class_reloptions - 1] = true; - + repl_null[Anum_pg_class_reloptions - 1] = true; repl_repl[Anum_pg_class_reloptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass), diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index a4abb29cf64..2b44afdbf25 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -2020,13 +2020,6 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params, Oid save_userid; int save_sec_context; int save_nestlevel; - VacuumParams toast_vacuum_params; - - /* - * This function scribbles on the parameters, so make a copy early to - * avoid affecting the TOAST table (if we do end up recursing to it). - */ - memcpy(&toast_vacuum_params, ¶ms, sizeof(VacuumParams)); /* Begin a transaction for vacuuming this relation */ StartTransactionCommand(); @@ -2341,11 +2334,10 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params, * relation. NB: This is only safe to do because we hold a session * lock on the main relation that prevents concurrent deletion. */ - toast_vacuum_params.options |= VACOPT_PROCESS_MAIN; - toast_vacuum_params.toast_parent = relid; + params.options |= VACOPT_PROCESS_MAIN; + params.toast_parent = relid; - vacuum_rel(toast_relid, NULL, toast_vacuum_params, bstrategy, - isTopLevel); + vacuum_rel(toast_relid, NULL, params, bstrategy, isTopLevel); } /* diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index a5a8db2ff88..c0e7cbf2cb8 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -2139,8 +2139,9 @@ do_autovacuum(void) { Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple); Oid relid; - AutoVacOpts *relopts; - bool free_relopts = false; + av_relation *hentry; + bool found; + AutoVacOpts *relopts = NULL; bool dovacuum; bool doanalyze; bool wraparound; @@ -2154,22 +2155,10 @@ do_autovacuum(void) relid = classForm->oid; - /* - * fetch reloptions -- if this toast table does not have them, try the - * main rel - */ - relopts = extract_autovac_opts(tuple, pg_class_desc); - if (relopts) - free_relopts = true; - else - { - av_relation *hentry; - bool found; - - hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found); - if (found && hentry->ar_hasrelopts) - relopts = &hentry->ar_reloptions; - } + /* Use reloptions from main rel. */ + hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found); + if (found && hentry->ar_hasrelopts) + relopts = &hentry->ar_reloptions; relation_needs_vacanalyze(relid, relopts, classForm, effective_multixact_freeze_max_age, @@ -2186,10 +2175,6 @@ do_autovacuum(void) table->score = scores.max; tables_to_process = lappend(tables_to_process, table); } - - /* Release stuff to avoid leakage */ - if (free_relopts) - pfree(relopts); } table_endscan(relScan); @@ -2826,7 +2811,7 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map, bool doanalyze; autovac_table *tab = NULL; bool wraparound; - AutoVacOpts *avopts; + AutoVacOpts *avopts = NULL; bool free_avopts = false; AutoVacuumScores scores; @@ -2838,13 +2823,15 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map, /* * Get the applicable reloptions. If it is a TOAST table, try to get the - * main table reloptions if the toast table itself doesn't have. + * main table reloptions. */ - avopts = extract_autovac_opts(classTup, pg_class_desc); - if (avopts) - free_avopts = true; - else if (classForm->relkind == RELKIND_TOASTVALUE && - table_toast_map != NULL) + if (classForm->relkind != RELKIND_TOASTVALUE) + { + avopts = extract_autovac_opts(classTup, pg_class_desc); + if (avopts) + free_avopts = true; + } + else if (table_toast_map) { av_relation *hentry; bool found; @@ -3127,8 +3114,7 @@ relation_needs_vacanalyze(Oid relid, /* * Determine vacuum/analyze equation parameters. We have two possible - * sources: the passed reloptions (which could be a main table or a toast - * table), or the autovacuum GUC variables. + * sources: the passed reloptions or the autovacuum GUC variables. */ /* -1 in autovac setting means use plain vacuum_scale_factor */ diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 73a56f1df1d..d089e02c216 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -1159,8 +1159,6 @@ ProcessUtilitySlow(ParseState *pstate, if (IsA(stmt, CreateStmt)) { CreateStmt *cstmt = (CreateStmt *) stmt; - Datum toast_options; - const char *const validnsps[] = HEAP_RELOPT_NAMESPACES; /* Remember transformed RangeVar for LIKE */ table_rv = cstmt->relation; @@ -1180,22 +1178,7 @@ ProcessUtilitySlow(ParseState *pstate, */ CommandCounterIncrement(); - /* - * parse and validate reloptions for the toast - * table - */ - toast_options = transformRelOptions((Datum) 0, - cstmt->options, - "toast", - validnsps, - true, - false); - (void) heap_reloptions(RELKIND_TOASTVALUE, - toast_options, - true); - - NewRelationCreateToastTable(address.objectId, - toast_options); + NewRelationCreateToastTable(address.objectId); } else if (IsA(stmt, CreateForeignTableStmt)) { diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c index 5a7afe62eab..18d49a6fc17 100644 --- a/src/bin/pg_upgrade/check.c +++ b/src/bin/pg_upgrade/check.c @@ -37,6 +37,7 @@ static void check_new_cluster_subscription_configuration(void); static void check_old_cluster_for_valid_slots(void); static void check_old_cluster_subscription_state(void); static void check_old_cluster_global_names(ClusterInfo *cluster); +static void check_for_toast_reloptions(ClusterInfo *cluster); /* * DataTypesUsageChecks - definitions of data type checks for the old cluster @@ -634,6 +635,9 @@ check_and_dump_old_cluster(void) check_for_prepared_transactions(&old_cluster); check_for_isn_and_int8_passing_mismatch(&old_cluster); + if (GET_MAJOR_VERSION(old_cluster.major_version) < 2000) + check_for_toast_reloptions(&old_cluster); + if (GET_MAJOR_VERSION(old_cluster.major_version) >= 1700) { /* @@ -2644,3 +2648,74 @@ check_old_cluster_global_names(ClusterInfo *cluster) else check_ok(); } + +/* + * Callback function for processing results of query for + * check_for_toast_reloptions()'s UpgradeTask. If the query returned any rows + * (i.e., the check failed), write the details to the report file. + */ +static void +process_toast_relopts_check(DbInfo *dbinfo, PGresult *res, void *arg) +{ + UpgradeTaskReport *report = (UpgradeTaskReport *) arg; + int ntups = PQntuples(res); + int i_nspname = PQfnumber(res, "nspname"); + int i_relname = PQfnumber(res, "relname"); + + if (ntups == 0) + return; + + if (report->file == NULL && + (report->file = fopen_priv(report->path, "w")) == NULL) + pg_fatal("could not open file \"%s\": %m", report->path); + + fprintf(report->file, "In database: %s\n", dbinfo->db_name); + + for (int rowno = 0; rowno < ntups; rowno++) + fprintf(report->file, " %s.%s\n", + PQgetvalue(res, rowno, i_nspname), + PQgetvalue(res, rowno, i_relname)); +} + +/* + * Verify that no storage parameters (a.k.a. reloptions) are defined for TOAST + * tables. + */ +static void +check_for_toast_reloptions(ClusterInfo *cluster) +{ + UpgradeTaskReport report; + UpgradeTask *task = upgrade_task_create(); + const char *query = "SELECT n.nspname, c.relname " + "FROM pg_catalog.pg_class c, " + " pg_catalog.pg_class tc, " + " pg_catalog.pg_namespace n " + "WHERE c.reltoastrelid = tc.oid AND " + " c.relnamespace = n.oid AND " + " tc.reloptions IS NOT NULL"; + + prep_status("Check for tables with TOAST storage parameters"); + + report.file = NULL; + snprintf(report.path, sizeof(report.path), "%s/%s", + log_opts.basedir, + "tables_with_toast_storage_parameters.txt"); + + upgrade_task_add_step(task, query, process_toast_relopts_check, + true, &report); + upgrade_task_run(task, cluster); + upgrade_task_free(task); + + if (report.file) + { + fclose(report.file); + pg_log(PG_REPORT, "fatal"); + pg_fatal("Your installation contains tables with TOAST storage parameters set, which is\n" + "not supported anymore. Consider remove the TOAST storage parameters using\n" + " ALTER TABLE ... RESET ( ... );\n" + "A list of tables with the problem is in the file:\n" + " %s", report.path); + } + else + check_ok(); +} diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h index e8cb7f7a627..4415c1ca9b5 100644 --- a/src/include/access/reloptions.h +++ b/src/include/access/reloptions.h @@ -40,26 +40,22 @@ typedef enum relopt_kind { RELOPT_KIND_LOCAL = 0, RELOPT_KIND_HEAP = (1 << 0), - RELOPT_KIND_TOAST = (1 << 1), - RELOPT_KIND_BTREE = (1 << 2), - RELOPT_KIND_HASH = (1 << 3), - RELOPT_KIND_GIN = (1 << 4), - RELOPT_KIND_GIST = (1 << 5), - RELOPT_KIND_ATTRIBUTE = (1 << 6), - RELOPT_KIND_TABLESPACE = (1 << 7), - RELOPT_KIND_SPGIST = (1 << 8), - RELOPT_KIND_VIEW = (1 << 9), - RELOPT_KIND_BRIN = (1 << 10), - RELOPT_KIND_PARTITIONED = (1 << 11), + RELOPT_KIND_BTREE = (1 << 1), + RELOPT_KIND_HASH = (1 << 2), + RELOPT_KIND_GIN = (1 << 3), + RELOPT_KIND_GIST = (1 << 4), + RELOPT_KIND_ATTRIBUTE = (1 << 5), + RELOPT_KIND_TABLESPACE = (1 << 6), + RELOPT_KIND_SPGIST = (1 << 7), + RELOPT_KIND_VIEW = (1 << 8), + RELOPT_KIND_BRIN = (1 << 9), + RELOPT_KIND_PARTITIONED = (1 << 10), /* if you add a new kind, make sure you update "last_default" too */ RELOPT_KIND_LAST_DEFAULT = RELOPT_KIND_PARTITIONED, /* some compilers treat enums as signed ints, so we can't use 1 << 31 */ RELOPT_KIND_MAX = (1 << 30) } relopt_kind; -/* reloption namespaces allowed for heaps -- currently only TOAST */ -#define HEAP_RELOPT_NAMESPACES { "toast", NULL } - /* generic struct to hold shared data */ typedef struct relopt_gen { diff --git a/src/include/catalog/toasting.h b/src/include/catalog/toasting.h index 0bc61a8fee9..13e5a8affcb 100644 --- a/src/include/catalog/toasting.h +++ b/src/include/catalog/toasting.h @@ -19,10 +19,10 @@ /* * toasting.c prototypes */ -extern void NewRelationCreateToastTable(Oid relOid, Datum reloptions); -extern void NewHeapCreateToastTable(Oid relOid, Datum reloptions, +extern void NewRelationCreateToastTable(Oid relOid); +extern void NewHeapCreateToastTable(Oid relOid, LOCKMODE lockmode, Oid OIDOldToast); -extern void AlterTableCreateToastTable(Oid relOid, Datum reloptions, +extern void AlterTableCreateToastTable(Oid relOid, LOCKMODE lockmode); extern void BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid); diff --git a/src/test/modules/injection_points/expected/vacuum.out b/src/test/modules/injection_points/expected/vacuum.out index 58df59fa927..dcfa729d05e 100644 --- a/src/test/modules/injection_points/expected/vacuum.out +++ b/src/test/modules/injection_points/expected/vacuum.out @@ -43,29 +43,29 @@ SELECT injection_points_attach('vacuum-truncate-enabled', 'notice'); (1 row) -- Check state of index_cleanup and truncate in VACUUM. -CREATE TABLE vac_tab_on_toast_off(i int, j text) WITH +CREATE TABLE vac_tab_on_toast(i int, j text) WITH (autovacuum_enabled=false, - vacuum_index_cleanup=true, toast.vacuum_index_cleanup=false, - vacuum_truncate=true, toast.vacuum_truncate=false); -CREATE TABLE vac_tab_off_toast_on(i int, j text) WITH + vacuum_index_cleanup=true, + vacuum_truncate=true); +CREATE TABLE vac_tab_off_toast(i int, j text) WITH (autovacuum_enabled=false, - vacuum_index_cleanup=false, toast.vacuum_index_cleanup=true, - vacuum_truncate=false, toast.vacuum_truncate=true); + vacuum_index_cleanup=false, + vacuum_truncate=false); -- Multiple relations should use their options in isolation. -VACUUM vac_tab_on_toast_off, vac_tab_off_toast_on; +VACUUM vac_tab_on_toast, vac_tab_off_toast; +NOTICE: notice triggered for injection point vacuum-index-cleanup-enabled +NOTICE: notice triggered for injection point vacuum-truncate-enabled NOTICE: notice triggered for injection point vacuum-index-cleanup-enabled NOTICE: notice triggered for injection point vacuum-truncate-enabled NOTICE: notice triggered for injection point vacuum-index-cleanup-disabled NOTICE: notice triggered for injection point vacuum-truncate-disabled NOTICE: notice triggered for injection point vacuum-index-cleanup-disabled NOTICE: notice triggered for injection point vacuum-truncate-disabled -NOTICE: notice triggered for injection point vacuum-index-cleanup-enabled -NOTICE: notice triggered for injection point vacuum-truncate-enabled -- Check "auto" case of index_cleanup and "truncate" controlled by -- its GUC. CREATE TABLE vac_tab_auto(i int, j text) WITH (autovacuum_enabled=false, - vacuum_index_cleanup=auto, toast.vacuum_index_cleanup=auto); + vacuum_index_cleanup=auto); SET vacuum_truncate = false; VACUUM vac_tab_auto; NOTICE: notice triggered for injection point vacuum-index-cleanup-auto @@ -80,8 +80,8 @@ NOTICE: notice triggered for injection point vacuum-index-cleanup-auto NOTICE: notice triggered for injection point vacuum-truncate-enabled RESET vacuum_truncate; DROP TABLE vac_tab_auto; -DROP TABLE vac_tab_on_toast_off; -DROP TABLE vac_tab_off_toast_on; +DROP TABLE vac_tab_on_toast; +DROP TABLE vac_tab_off_toast; -- Cleanup SELECT injection_points_detach('vacuum-index-cleanup-auto'); injection_points_detach diff --git a/src/test/modules/injection_points/sql/vacuum.sql b/src/test/modules/injection_points/sql/vacuum.sql index 23760dd0f38..ee7a2e0566e 100644 --- a/src/test/modules/injection_points/sql/vacuum.sql +++ b/src/test/modules/injection_points/sql/vacuum.sql @@ -11,22 +11,22 @@ SELECT injection_points_attach('vacuum-truncate-disabled', 'notice'); SELECT injection_points_attach('vacuum-truncate-enabled', 'notice'); -- Check state of index_cleanup and truncate in VACUUM. -CREATE TABLE vac_tab_on_toast_off(i int, j text) WITH +CREATE TABLE vac_tab_on_toast(i int, j text) WITH (autovacuum_enabled=false, - vacuum_index_cleanup=true, toast.vacuum_index_cleanup=false, - vacuum_truncate=true, toast.vacuum_truncate=false); -CREATE TABLE vac_tab_off_toast_on(i int, j text) WITH + vacuum_index_cleanup=true, + vacuum_truncate=true); +CREATE TABLE vac_tab_off_toast(i int, j text) WITH (autovacuum_enabled=false, - vacuum_index_cleanup=false, toast.vacuum_index_cleanup=true, - vacuum_truncate=false, toast.vacuum_truncate=true); + vacuum_index_cleanup=false, + vacuum_truncate=false); -- Multiple relations should use their options in isolation. -VACUUM vac_tab_on_toast_off, vac_tab_off_toast_on; +VACUUM vac_tab_on_toast, vac_tab_off_toast; -- Check "auto" case of index_cleanup and "truncate" controlled by -- its GUC. CREATE TABLE vac_tab_auto(i int, j text) WITH (autovacuum_enabled=false, - vacuum_index_cleanup=auto, toast.vacuum_index_cleanup=auto); + vacuum_index_cleanup=auto); SET vacuum_truncate = false; VACUUM vac_tab_auto; SET vacuum_truncate = true; @@ -34,8 +34,8 @@ VACUUM vac_tab_auto; RESET vacuum_truncate; DROP TABLE vac_tab_auto; -DROP TABLE vac_tab_on_toast_off; -DROP TABLE vac_tab_off_toast_on; +DROP TABLE vac_tab_on_toast; +DROP TABLE vac_tab_off_toast; -- Cleanup SELECT injection_points_detach('vacuum-index-cleanup-auto'); diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out index 6dd22be0e8d..435e6beea0f 100644 --- a/src/test/regress/expected/alter_table.out +++ b/src/test/regress/expected/alter_table.out @@ -2860,15 +2860,6 @@ select * from my_locks order by 1; pg_toast | ShareUpdateExclusiveLock (2 rows) -commit; -begin; alter table alterlock set (toast.autovacuum_enabled = off); -select * from my_locks order by 1; - relname | max_lockmode ------------+-------------------------- - alterlock | ShareUpdateExclusiveLock - pg_toast | ShareUpdateExclusiveLock -(2 rows) - commit; begin; alter table alterlock set (autovacuum_enabled = off); select * from my_locks order by 1; diff --git a/src/test/regress/expected/reloptions.out b/src/test/regress/expected/reloptions.out index e3a974f2611..eff5fbece60 100644 --- a/src/test/regress/expected/reloptions.out +++ b/src/test/regress/expected/reloptions.out @@ -120,7 +120,6 @@ SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; DROP TABLE reloptions_test; CREATE TEMP TABLE reloptions_test(i INT NOT NULL, j text) WITH (vacuum_truncate=false, - toast.vacuum_truncate=false, autovacuum_enabled=false); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; reloptions @@ -142,9 +141,9 @@ SELECT pg_relation_size('reloptions_test') > 0; SELECT reloptions FROM pg_class WHERE oid = (SELECT reltoastrelid FROM pg_class WHERE oid = 'reloptions_test'::regclass); - reloptions -------------------------- - {vacuum_truncate=false} + reloptions +------------ + (1 row) ALTER TABLE reloptions_test RESET (vacuum_truncate); @@ -165,56 +164,11 @@ SELECT pg_relation_size('reloptions_test') = 0; t (1 row) --- Test toast.* options -DROP TABLE reloptions_test; -CREATE TABLE reloptions_test (s VARCHAR) - WITH (toast.autovacuum_vacuum_cost_delay = 23); -SELECT reltoastrelid as toast_oid - FROM pg_class WHERE oid = 'reloptions_test'::regclass \gset -SELECT reloptions FROM pg_class WHERE oid = :toast_oid; - reloptions ------------------------------------ - {autovacuum_vacuum_cost_delay=23} -(1 row) - -ALTER TABLE reloptions_test SET (toast.autovacuum_vacuum_cost_delay = 24); -SELECT reloptions FROM pg_class WHERE oid = :toast_oid; - reloptions ------------------------------------ - {autovacuum_vacuum_cost_delay=24} -(1 row) - -ALTER TABLE reloptions_test RESET (toast.autovacuum_vacuum_cost_delay); -SELECT reloptions FROM pg_class WHERE oid = :toast_oid; - reloptions ------------- - -(1 row) - --- Fail on non-existent options in toast namespace -CREATE TABLE reloptions_test2 (i int) WITH (toast.not_existing_option = 42); -ERROR: unrecognized parameter "not_existing_option" --- Mix TOAST & heap -DROP TABLE reloptions_test; -CREATE TABLE reloptions_test (s VARCHAR) WITH - (toast.autovacuum_vacuum_cost_delay = 23, - autovacuum_vacuum_cost_delay = 24, fillfactor = 40); -SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; - reloptions -------------------------------------------------- - {autovacuum_vacuum_cost_delay=24,fillfactor=40} -(1 row) - -SELECT reloptions FROM pg_class WHERE oid = ( - SELECT reltoastrelid FROM pg_class WHERE oid = 'reloptions_test'::regclass); - reloptions ------------------------------------ - {autovacuum_vacuum_cost_delay=23} -(1 row) - -- -- CREATE INDEX, ALTER INDEX for btrees -- +DROP TABLE reloptions_test; +CREATE TABLE reloptions_test (s VARCHAR); CREATE INDEX reloptions_test_idx ON reloptions_test (s) WITH (fillfactor=30); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test_idx'::regclass; reloptions diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out index d4696bc3325..d551ef57d50 100644 --- a/src/test/regress/expected/vacuum.out +++ b/src/test/regress/expected/vacuum.out @@ -209,14 +209,6 @@ VACUUM no_index_cleanup; INSERT INTO no_index_cleanup(i, t) VALUES (generate_series(31,60), repeat('1234567890',269)); DELETE FROM no_index_cleanup WHERE i < 45; --- Only toast index is cleaned up. -ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = off, - toast.vacuum_index_cleanup = yes); -VACUUM no_index_cleanup; --- Only parent is cleaned up. -ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = true, - toast.vacuum_index_cleanup = false); -VACUUM no_index_cleanup; -- Test some extra relations. VACUUM (INDEX_CLEANUP FALSE) vaccluster; VACUUM (INDEX_CLEANUP AUTO) vactst; -- index cleanup option is ignored if no indexes diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql index f5f13bbd3e7..410465dc022 100644 --- a/src/test/regress/sql/alter_table.sql +++ b/src/test/regress/sql/alter_table.sql @@ -1784,10 +1784,6 @@ begin; alter table alterlock reset (fillfactor); select * from my_locks order by 1; commit; -begin; alter table alterlock set (toast.autovacuum_enabled = off); -select * from my_locks order by 1; -commit; - begin; alter table alterlock set (autovacuum_enabled = off); select * from my_locks order by 1; commit; diff --git a/src/test/regress/sql/reloptions.sql b/src/test/regress/sql/reloptions.sql index 680c8bf8614..0809a2ae0e4 100644 --- a/src/test/regress/sql/reloptions.sql +++ b/src/test/regress/sql/reloptions.sql @@ -75,7 +75,6 @@ DROP TABLE reloptions_test; CREATE TEMP TABLE reloptions_test(i INT NOT NULL, j text) WITH (vacuum_truncate=false, - toast.vacuum_truncate=false, autovacuum_enabled=false); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; INSERT INTO reloptions_test VALUES (1, NULL), (NULL, NULL); @@ -94,39 +93,12 @@ INSERT INTO reloptions_test VALUES (1, NULL), (NULL, NULL); VACUUM (FREEZE, DISABLE_PAGE_SKIPPING) reloptions_test; SELECT pg_relation_size('reloptions_test') = 0; --- Test toast.* options -DROP TABLE reloptions_test; - -CREATE TABLE reloptions_test (s VARCHAR) - WITH (toast.autovacuum_vacuum_cost_delay = 23); -SELECT reltoastrelid as toast_oid - FROM pg_class WHERE oid = 'reloptions_test'::regclass \gset -SELECT reloptions FROM pg_class WHERE oid = :toast_oid; - -ALTER TABLE reloptions_test SET (toast.autovacuum_vacuum_cost_delay = 24); -SELECT reloptions FROM pg_class WHERE oid = :toast_oid; - -ALTER TABLE reloptions_test RESET (toast.autovacuum_vacuum_cost_delay); -SELECT reloptions FROM pg_class WHERE oid = :toast_oid; - --- Fail on non-existent options in toast namespace -CREATE TABLE reloptions_test2 (i int) WITH (toast.not_existing_option = 42); - --- Mix TOAST & heap -DROP TABLE reloptions_test; - -CREATE TABLE reloptions_test (s VARCHAR) WITH - (toast.autovacuum_vacuum_cost_delay = 23, - autovacuum_vacuum_cost_delay = 24, fillfactor = 40); - -SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass; -SELECT reloptions FROM pg_class WHERE oid = ( - SELECT reltoastrelid FROM pg_class WHERE oid = 'reloptions_test'::regclass); - -- -- CREATE INDEX, ALTER INDEX for btrees -- +DROP TABLE reloptions_test; +CREATE TABLE reloptions_test (s VARCHAR); CREATE INDEX reloptions_test_idx ON reloptions_test (s) WITH (fillfactor=30); SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test_idx'::regclass; diff --git a/src/test/regress/sql/vacuum.sql b/src/test/regress/sql/vacuum.sql index 247b8e23b23..37a84fd9145 100644 --- a/src/test/regress/sql/vacuum.sql +++ b/src/test/regress/sql/vacuum.sql @@ -175,14 +175,6 @@ VACUUM no_index_cleanup; INSERT INTO no_index_cleanup(i, t) VALUES (generate_series(31,60), repeat('1234567890',269)); DELETE FROM no_index_cleanup WHERE i < 45; --- Only toast index is cleaned up. -ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = off, - toast.vacuum_index_cleanup = yes); -VACUUM no_index_cleanup; --- Only parent is cleaned up. -ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = true, - toast.vacuum_index_cleanup = false); -VACUUM no_index_cleanup; -- Test some extra relations. VACUUM (INDEX_CLEANUP FALSE) vaccluster; VACUUM (INDEX_CLEANUP AUTO) vactst; -- index cleanup option is ignored if no indexes -- 2.50.1 (Apple Git-155) --g1KZ71ry6DNksXN0-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. @ 2026-05-12 10:27 Antonin Houska <[email protected]> 0 siblings, 0 replies; 93+ messages in thread From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw) The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost --- src/backend/access/transam/xact.c | 2 + src/backend/commands/repack_worker.c | 2 + src/test/isolation/isolationtester.c | 9 +- .../expected/repack_running_xacts.out | 81 ++++++++++++ .../specs/repack_running_xacts.spec | 119 ++++++++++++++++++ 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 5586fbe5b07..b63ee166028 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -65,6 +65,7 @@ #include "utils/builtins.h" #include "utils/combocid.h" #include "utils/guc.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" #include "utils/relmapper.h" @@ -2428,6 +2429,7 @@ CommitTransaction(void) * must be done _before_ releasing locks we hold and _after_ * RecordTransactionCommit. */ + INJECTION_POINT("before-end-transaction", NULL); ProcArrayEndTransaction(MyProc, latestXid); /* diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index c40f8c98e06..6835626d677 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -26,6 +26,7 @@ #include "storage/ipc.h" #include "storage/proc.h" #include "tcop/tcopprot.h" +#include "utils/injection_point.h" #include "utils/memutils.h" #define REPL_PLUGIN_NAME "pgrepack" @@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid) * Neither prepare_write nor do_write callback nor update_progress is * useful for us. */ + INJECTION_POINT("before-create-decoding-context", NULL); ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c index 440c875b8ac..8f17ee412c9 100644 --- a/src/test/isolation/isolationtester.c +++ b/src/test/isolation/isolationtester.c @@ -216,15 +216,22 @@ main(int argc, char **argv) * exactly expect concurrent use of test tables. However, autovacuum will * occasionally take AccessExclusiveLock to truncate a table, and we must * ignore that transient wait. + * + * If the session's backend is blocked, and if its background worker is + * waiting on an injection point, we assume that the injection point is + * the reason for the backend to be blocked. That's what we check in the + * second query of the UNION. XXX Should we use a separate query for that? */ initPQExpBuffer(&wait_query); appendPQExpBufferStr(&wait_query, + "WITH blocking(res) AS (" "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{"); /* The spec syntax requires at least one session; assume that here. */ appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str); for (i = 2; i < nconns; i++) appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str); - appendPQExpBufferStr(&wait_query, "}')"); + appendPQExpBufferStr(&wait_query, "}') UNION " + "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking"); res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out new file mode 100644 index 00000000000..271fe2b97cb --- /dev/null +++ b/src/test/modules/injection_points/expected/repack_running_xacts.out @@ -0,0 +1,81 @@ +Parsed test spec with 5 sessions + +starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check +injection_points_attach +----------------------- + +(1 row) + +step repack: + REPACK (CONCURRENTLY) repack_test; + <waiting ...> +step s3_assign_xid: + BEGIN; + INSERT INTO aux VALUES (1); + +step wakeup_bcdc: + SELECT injection_points_wakeup('before-create-decoding-context'); + +injection_points_wakeup +----------------------- + +(1 row) + +step s4_changes: + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); + +step s4_attach: + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); + +injection_points_set_local +-------------------------- + +(1 row) + +injection_points_attach +----------------------- + +(1 row) + +step s4_commit: + COMMIT; + <waiting ...> +step s3_commit: + COMMIT; + +step s5_assign_xid: + BEGIN; + INSERT INTO aux VALUES (2); + +step wakeup_bet: + SELECT injection_points_wakeup('before-end-transaction'); + +injection_points_wakeup +----------------------- + +(1 row) + +step repack: <... completed> +step s4_commit: <... completed> +step s5_commit: + COMMIT; + +step check: + TABLE repack_test; + +i|j +-+- +(0 rows) + +injection_points_detach +----------------------- + +(1 row) + +injection_points_detach +----------------------- + +(1 row) + diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec new file mode 100644 index 00000000000..1f878514046 --- /dev/null +++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec @@ -0,0 +1,119 @@ +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE repack_test(i int PRIMARY KEY, j int); + CREATE TABLE aux(i int); +} + +teardown +{ + DROP TABLE repack_test; + DROP TABLE aux; + DROP EXTENSION injection_points; +} + +session s1 +setup +{ + SELECT injection_points_attach('before-create-decoding-context', 'wait'); +} +step repack +{ + REPACK (CONCURRENTLY) repack_test; +} +step check +{ + TABLE repack_test; +} +teardown +{ + SELECT injection_points_detach('before-create-decoding-context'); +} + +session s2 +step wakeup_bcdc +{ + SELECT injection_points_wakeup('before-create-decoding-context'); +} +step wakeup_bet +{ + SELECT injection_points_wakeup('before-end-transaction'); +} + +session s3 +step s3_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (1); +} +step s3_commit +{ + COMMIT; +} + +session s4 +step s4_changes +{ + BEGIN; + INSERT INTO repack_test(i, j) VALUES (1, 1); +} +# Do not attach in the setup section, that would be too soon. +step s4_attach +{ + SELECT injection_points_set_local(); + SELECT injection_points_attach('before-end-transaction', 'wait'); +} +step s4_commit +{ + COMMIT; +} +teardown +{ + SELECT injection_points_detach('before-end-transaction'); +} + +session s5 +step s5_assign_xid +{ + BEGIN; + INSERT INTO aux VALUES (2); +} +step s5_commit +{ + COMMIT; +} + +permutation +repack +# Assign XID so that a running transaction prevents the snapshot builder from +# reaching CONSISTENT state immediately. It will wait for this to complete +# after having reached BUILDING_SNAPSHOT. +s3_assign_xid +# Let the decoding setup start. +wakeup_bcdc +# Likewise, the snapshot builder will wait for the s4's xact to complete after +# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it +# do some changes. +s4_changes +# Attach to the 'before-end-transaction' injection point that s4 will need +# during commit. +s4_attach +# Only write commit record for s4, but do not remove the xact from procarray +# yet. Thus the snapshot builder still needs to wait. +s4_commit +# Let the snapshot builder proceed to FULL_SNAPSHOT. +s3_commit +# Start another transaction so that CONSISTENT is not reached "directly", +# i.e. due to no running transaction. It's important here that builder->xmin +# does not advance. +s5_assign_xid +# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since +# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state +# did not allow decoding of COMMIT records yet), the snapshot builder will +# consider s4 running. This is also due to returning from +# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin. +wakeup_bet +# s5 is not needed anymore +s5_commit +# Show that the data changes performed by s4 are lost. +check -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 93+ messages in thread
end of thread, other threads:[~2026-05-12 10:27 UTC | newest] Thread overview: 93+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-03-21 01:47 [PATCH v1 1/2] Report wait event for cost-based vacuum delay Justin Pryzby <[email protected]> 2025-12-09 19:17 [PATCH v1 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v7 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v8.1 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v8 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v4 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v4 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v8.1 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v5 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v8 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v3 6/7] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v7 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v2 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v5 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v3 6/7] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v2 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2025-12-09 19:17 [PATCH v1 5/6] Handle pg_get_expr default args in system_functions.sql Mark Wong <[email protected]> 2026-04-07 20:30 [PATCH v4 1/1] remove toast reloptions Nathan Bossart <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]> 2026-05-12 10:27 [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix. Antonin Houska <[email protected]>
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