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[PATCH v12 1/7] Row pattern recognition patch for raw parser.
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* [PATCH v12 1/7] Row pattern recognition patch for raw parser.
@ 2023-12-04 11:23 Tatsuo Ishii <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw)

---
 src/backend/parser/gram.y       | 222 ++++++++++++++++++++++++++++++--
 src/include/nodes/parsenodes.h  |  56 ++++++++
 src/include/parser/kwlist.h     |   8 ++
 src/include/parser/parse_node.h |   1 +
 4 files changed, 273 insertions(+), 14 deletions(-)

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d631ac89a9..5a77fca17f 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -251,6 +251,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	DefElem	   *defelt;
 	SortBy	   *sortby;
 	WindowDef  *windef;
+	RPCommonSyntax	*rpcom;
+	RPSubsetItem	*rpsubset;
 	JoinExpr   *jexpr;
 	IndexElem  *ielem;
 	StatsElem  *selem;
@@ -278,6 +280,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	MergeWhenClause *mergewhen;
 	struct KeyActions *keyactions;
 	struct KeyAction *keyaction;
+	RPSkipTo	skipto;
 }
 
 %type <node>	stmt toplevel_stmt schema_stmt routine_body_stmt
@@ -453,8 +456,12 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				TriggerTransitions TriggerReferencing
 				vacuum_relation_list opt_vacuum_relation_list
 				drop_option_list pub_obj_list
-
-%type <node>	opt_routine_body
+				row_pattern_measure_list row_pattern_definition_list
+				opt_row_pattern_subset_clause
+				row_pattern_subset_list row_pattern_subset_rhs
+				row_pattern
+%type <rpsubset>	 row_pattern_subset_item
+%type <node>	opt_routine_body row_pattern_term
 %type <groupclause> group_clause
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
@@ -551,6 +558,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <range>	relation_expr_opt_alias
 %type <node>	tablesample_clause opt_repeatable_clause
 %type <target>	target_el set_target insert_column_item
+				row_pattern_measure_item row_pattern_definition
+%type <skipto>	first_or_last
 
 %type <str>		generic_option_name
 %type <node>	generic_option_arg
@@ -633,6 +642,9 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <list>	window_clause window_definition_list opt_partition_clause
 %type <windef>	window_definition over_clause window_specification
 				opt_frame_clause frame_extent frame_bound
+%type <rpcom>	opt_row_pattern_common_syntax opt_row_pattern_skip_to
+%type <boolean>	opt_row_pattern_initial_or_seek
+%type <list>	opt_row_pattern_measures
 %type <ival>	opt_window_exclusion_clause
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
@@ -659,7 +671,6 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				json_object_constructor_null_clause_opt
 				json_array_constructor_null_clause_opt
 
-
 /*
  * Non-keyword token types.  These are hard-wired into the "flex" lexer.
  * They must be listed first so that their numeric codes do not depend on
@@ -702,7 +713,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
 	DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
-	DEFERRABLE DEFERRED DEFINER DELETE_P DELIMITER DELIMITERS DEPENDS DEPTH DESC
+	DEFERRABLE DEFERRED DEFINE DEFINER DELETE_P DELIMITER DELIMITERS DEPENDS DEPTH DESC
 	DETACH DICTIONARY DISABLE_P DISCARD DISTINCT DO DOCUMENT_P DOMAIN_P
 	DOUBLE_P DROP
 
@@ -718,7 +729,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	HANDLER HAVING HEADER_P HOLD HOUR_P
 
 	IDENTITY_P IF_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IMPORT_P IN_P INCLUDE
-	INCLUDING INCREMENT INDENT INDEX INDEXES INHERIT INHERITS INITIALLY INLINE_P
+	INCLUDING INCREMENT INDENT INDEX INDEXES INHERIT INHERITS INITIAL INITIALLY INLINE_P
 	INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER
 	INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION
 
@@ -731,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
 	LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
 
-	MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE METHOD
+	MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MEASURES MERGE METHOD
 	MINUTE_P MINVALUE MODE MONTH_P MOVE
 
 	NAME_P NAMES NATIONAL NATURAL NCHAR NEW NEXT NFC NFD NFKC NFKD NO NONE
@@ -743,8 +754,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	ORDER ORDINALITY OTHERS OUT_P OUTER_P
 	OVER OVERLAPS OVERLAY OVERRIDING OWNED OWNER
 
-	PARALLEL PARAMETER PARSER PARTIAL PARTITION PASSING PASSWORD
-	PLACING PLANS POLICY
+	PARALLEL PARAMETER PARSER PARTIAL PARTITION PASSING PASSWORD PAST
+	PATTERN_P PERMUTE PLACING PLANS POLICY
 	POSITION PRECEDING PRECISION PRESERVE PREPARE PREPARED PRIMARY
 	PRIOR PRIVILEGES PROCEDURAL PROCEDURE PROCEDURES PROGRAM PUBLICATION
 
@@ -755,12 +766,13 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	RESET RESTART RESTRICT RETURN RETURNING RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP
 	ROUTINE ROUTINES ROW ROWS RULE
 
-	SAVEPOINT SCALAR SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT
+	SAVEPOINT SCALAR SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SEEK SELECT
 	SEQUENCE SEQUENCES
+
 	SERIALIZABLE SERVER SESSION SESSION_USER SET SETS SETOF SHARE SHOW
 	SIMILAR SIMPLE SKIP SMALLINT SNAPSHOT SOME SQL_P STABLE STANDALONE_P
 	START STATEMENT STATISTICS STDIN STDOUT STORAGE STORED STRICT_P STRIP_P
-	SUBSCRIPTION SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P SYSTEM_USER
+	SUBSCRIPTION SUBSET SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P SYSTEM_USER
 
 	TABLE TABLES TABLESAMPLE TABLESPACE TEMP TEMPLATE TEMPORARY TEXT_P THEN
 	TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSFORM
@@ -866,6 +878,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %nonassoc	UNBOUNDED		/* ideally would have same precedence as IDENT */
 %nonassoc	IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
 			SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT
+%nonassoc	MEASURES AFTER INITIAL SEEK PATTERN_P
 %left		Op OPERATOR		/* multi-character ops and user-defined operators */
 %left		'+' '-'
 %left		'*' '/' '%'
@@ -15914,7 +15927,8 @@ over_clause: OVER window_specification
 		;
 
 window_specification: '(' opt_existing_window_name opt_partition_clause
-						opt_sort_clause opt_frame_clause ')'
+						opt_sort_clause opt_row_pattern_measures opt_frame_clause
+						opt_row_pattern_common_syntax ')'
 				{
 					WindowDef  *n = makeNode(WindowDef);
 
@@ -15922,10 +15936,12 @@ window_specification: '(' opt_existing_window_name opt_partition_clause
 					n->refname = $2;
 					n->partitionClause = $3;
 					n->orderClause = $4;
+					n->rowPatternMeasures = $5;
 					/* copy relevant fields of opt_frame_clause */
-					n->frameOptions = $5->frameOptions;
-					n->startOffset = $5->startOffset;
-					n->endOffset = $5->endOffset;
+					n->frameOptions = $6->frameOptions;
+					n->startOffset = $6->startOffset;
+					n->endOffset = $6->endOffset;
+					n->rpCommonSyntax = $7;
 					n->location = @1;
 					$$ = n;
 				}
@@ -15949,6 +15965,31 @@ opt_partition_clause: PARTITION BY expr_list		{ $$ = $3; }
 			| /*EMPTY*/								{ $$ = NIL; }
 		;
 
+/*
+ * ROW PATTERN_P MEASURES
+ */
+opt_row_pattern_measures: MEASURES row_pattern_measure_list	{ $$ = $2; }
+			| /*EMPTY*/								{ $$ = NIL; }
+		;
+
+row_pattern_measure_list:
+			row_pattern_measure_item
+					{ $$ = list_make1($1); }
+			| row_pattern_measure_list ',' row_pattern_measure_item
+					{ $$ = lappend($1, $3); }
+		;
+
+row_pattern_measure_item:
+			a_expr AS ColLabel
+				{
+					$$ = makeNode(ResTarget);
+					$$->name = $3;
+					$$->indirection = NIL;
+					$$->val = (Node *) $1;
+					$$->location = @1;
+				}
+		;
+
 /*
  * For frame clauses, we return a WindowDef, but only some fields are used:
  * frameOptions, startOffset, and endOffset.
@@ -16108,6 +16149,143 @@ opt_window_exclusion_clause:
 			| /*EMPTY*/				{ $$ = 0; }
 		;
 
+opt_row_pattern_common_syntax:
+opt_row_pattern_skip_to opt_row_pattern_initial_or_seek
+				PATTERN_P '(' row_pattern ')'
+				opt_row_pattern_subset_clause
+				DEFINE row_pattern_definition_list
+			{
+				RPCommonSyntax *n = makeNode(RPCommonSyntax);
+				n->rpSkipTo = $1->rpSkipTo;
+				n->rpSkipVariable = $1->rpSkipVariable;
+				n->initial = $2;
+				n->rpPatterns = $5;
+				n->rpSubsetClause = $7;
+				n->rpDefs = $9;
+				$$ = n;
+			}
+			| /*EMPTY*/		{ $$ = NULL; }
+	;
+
+opt_row_pattern_skip_to:
+			AFTER MATCH SKIP TO NEXT ROW
+				{
+					RPCommonSyntax *n = makeNode(RPCommonSyntax);
+					n->rpSkipTo = ST_NEXT_ROW;
+					n->rpSkipVariable = NULL;
+					$$ = n;
+			}
+			| AFTER MATCH SKIP PAST LAST_P ROW
+				{
+					RPCommonSyntax *n = makeNode(RPCommonSyntax);
+					n->rpSkipTo = ST_PAST_LAST_ROW;
+					n->rpSkipVariable = NULL;
+					$$ = n;
+				}
+			| AFTER MATCH SKIP TO first_or_last ColId
+				{
+					RPCommonSyntax *n = makeNode(RPCommonSyntax);
+					n->rpSkipTo = $5;
+					n->rpSkipVariable = $6;
+					$$ = n;
+				}
+/*
+			| AFTER MATCH SKIP TO LAST_P ColId		%prec LAST_P
+				{
+					RPCommonSyntax *n = makeNode(RPCommonSyntax);
+					n->rpSkipTo = ST_LAST_VARIABLE;
+					n->rpSkipVariable = $6;
+					$$ = n;
+				}
+			| AFTER MATCH SKIP TO ColId
+				{
+					RPCommonSyntax *n = makeNode(RPCommonSyntax);
+					n->rpSkipTo = ST_VARIABLE;
+					n->rpSkipVariable = $5;
+					$$ = n;
+				}
+*/
+			| /*EMPTY*/
+				{
+					RPCommonSyntax *n = makeNode(RPCommonSyntax);
+					/* temporary set default to ST_NEXT_ROW */
+					n->rpSkipTo = ST_PAST_LAST_ROW;
+					n->rpSkipVariable = NULL;
+					$$ = n;
+				}
+	;
+
+first_or_last:
+			FIRST_P		{ $$ = ST_FIRST_VARIABLE; }
+			| LAST_P	{ $$ = ST_LAST_VARIABLE; }
+	;
+
+opt_row_pattern_initial_or_seek:
+			INITIAL			{ $$ = true; }
+			| SEEK
+				{
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("SEEK is not supported"),
+							 errhint("Use INITIAL."),
+							 parser_errposition(@1)));
+				}
+			| /*EMPTY*/		{ $$ = true; }
+		;
+
+row_pattern:
+			row_pattern_term							{ $$ = list_make1($1); }
+			| row_pattern row_pattern_term				{ $$ = lappend($1, $2); }
+		;
+
+row_pattern_term:
+			ColId	{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "", (Node *)makeString($1), NULL, @1); }
+			| ColId '*'	{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "*", (Node *)makeString($1), NULL, @1); }
+			| ColId '+'	{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "+", (Node *)makeString($1), NULL, @1); }
+			| ColId '?'	{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "?", (Node *)makeString($1), NULL, @1); }
+		;
+
+opt_row_pattern_subset_clause:
+			SUBSET row_pattern_subset_list	{ $$ = $2; }
+			| /*EMPTY*/												{ $$ = NIL; }
+		;
+
+row_pattern_subset_list:
+			row_pattern_subset_item									{ $$ = list_make1($1); }
+			| row_pattern_subset_list ',' row_pattern_subset_item	{ $$ = lappend($1, $3); }
+			| /*EMPTY*/												{ $$ = NIL; }
+		;
+
+row_pattern_subset_item: ColId '=' '(' row_pattern_subset_rhs ')'
+			{
+				RPSubsetItem *n = makeNode(RPSubsetItem);
+				n->name = $1;
+				n->rhsVariable = $4;
+				$$ = n;
+			}
+		;
+
+row_pattern_subset_rhs:
+			ColId								{ $$ = list_make1(makeStringConst($1, @1)); }
+			| row_pattern_subset_rhs ',' ColId	{ $$ = lappend($1, makeStringConst($3, @1)); }
+			| /*EMPTY*/							{ $$ = NIL; }
+		;
+
+row_pattern_definition_list:
+			row_pattern_definition										{ $$ = list_make1($1); }
+			| row_pattern_definition_list ',' row_pattern_definition	{ $$ = lappend($1, $3); }
+		;
+
+row_pattern_definition:
+			ColId AS a_expr
+				{
+					$$ = makeNode(ResTarget);
+					$$->name = $1;
+					$$->indirection = NIL;
+					$$->val = (Node *) $3;
+					$$->location = @1;
+				}
+		;
 
 /*
  * Supporting nonterminals for expressions.
@@ -17217,6 +17395,7 @@ unreserved_keyword:
 			| INDEXES
 			| INHERIT
 			| INHERITS
+			| INITIAL
 			| INLINE_P
 			| INPUT_P
 			| INSENSITIVE
@@ -17244,6 +17423,7 @@ unreserved_keyword:
 			| MATCHED
 			| MATERIALIZED
 			| MAXVALUE
+			| MEASURES
 			| MERGE
 			| METHOD
 			| MINUTE_P
@@ -17286,6 +17466,9 @@ unreserved_keyword:
 			| PARTITION
 			| PASSING
 			| PASSWORD
+			| PAST
+			| PATTERN_P
+			| PERMUTE
 			| PLANS
 			| POLICY
 			| PRECEDING
@@ -17336,6 +17519,7 @@ unreserved_keyword:
 			| SEARCH
 			| SECOND_P
 			| SECURITY
+			| SEEK
 			| SEQUENCE
 			| SEQUENCES
 			| SERIALIZABLE
@@ -17361,6 +17545,7 @@ unreserved_keyword:
 			| STRICT_P
 			| STRIP_P
 			| SUBSCRIPTION
+			| SUBSET
 			| SUPPORT
 			| SYSID
 			| SYSTEM_P
@@ -17548,6 +17733,7 @@ reserved_keyword:
 			| CURRENT_USER
 			| DEFAULT
 			| DEFERRABLE
+			| DEFINE
 			| DESC
 			| DISTINCT
 			| DO
@@ -17710,6 +17896,7 @@ bare_label_keyword:
 			| DEFAULTS
 			| DEFERRABLE
 			| DEFERRED
+			| DEFINE
 			| DEFINER
 			| DELETE_P
 			| DELIMITER
@@ -17785,6 +17972,7 @@ bare_label_keyword:
 			| INDEXES
 			| INHERIT
 			| INHERITS
+			| INITIAL
 			| INITIALLY
 			| INLINE_P
 			| INNER_P
@@ -17834,6 +18022,7 @@ bare_label_keyword:
 			| MATCHED
 			| MATERIALIZED
 			| MAXVALUE
+			| MEASURES
 			| MERGE
 			| METHOD
 			| MINVALUE
@@ -17887,6 +18076,9 @@ bare_label_keyword:
 			| PARTITION
 			| PASSING
 			| PASSWORD
+			| PAST
+			| PATTERN_P
+			| PERMUTE
 			| PLACING
 			| PLANS
 			| POLICY
@@ -17943,6 +18135,7 @@ bare_label_keyword:
 			| SCROLL
 			| SEARCH
 			| SECURITY
+			| SEEK
 			| SELECT
 			| SEQUENCE
 			| SEQUENCES
@@ -17974,6 +18167,7 @@ bare_label_keyword:
 			| STRICT_P
 			| STRIP_P
 			| SUBSCRIPTION
+			| SUBSET
 			| SUBSTRING
 			| SUPPORT
 			| SYMMETRIC
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index e494309da8..094c603887 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -540,6 +540,44 @@ typedef struct SortBy
 	int			location;		/* operator location, or -1 if none/unknown */
 } SortBy;
 
+/*
+ * AFTER MATCH row pattern skip to types in row pattern common syntax
+ */
+typedef enum RPSkipTo
+{
+	ST_NONE,					/* AFTER MATCH omitted */
+	ST_NEXT_ROW,				/* SKIP TO NEXT ROW */
+	ST_PAST_LAST_ROW,			/* SKIP TO PAST LAST ROW */
+	ST_FIRST_VARIABLE,			/* SKIP TO FIRST variable name */
+	ST_LAST_VARIABLE,			/* SKIP TO LAST variable name */
+	ST_VARIABLE					/* SKIP TO variable name */
+} RPSkipTo;
+
+/*
+ * Row Pattern SUBSET clause item
+ */
+typedef struct RPSubsetItem
+{
+	NodeTag		type;
+	char	   *name;			/* Row Pattern SUBSET clause variable name */
+	List	   *rhsVariable;	/* Row Pattern SUBSET rhs variables (list of char *string) */
+} RPSubsetItem;
+
+/*
+ * RowPatternCommonSyntax - raw representation of row pattern common syntax
+ *
+ */
+typedef struct RPCommonSyntax
+{
+	NodeTag		type;
+	RPSkipTo	rpSkipTo;		/* Row Pattern AFTER MATCH SKIP type */
+	char	   *rpSkipVariable;	/* Row Pattern Skip To variable name, if any */
+	bool		initial;		/* true if <row pattern initial or seek> is initial */
+	List	   *rpPatterns;		/* PATTERN variables (list of A_Expr) */
+	List	   *rpSubsetClause;	/* row pattern subset clause (list of RPSubsetItem), if any */
+	List	   *rpDefs;			/* row pattern definitions clause (list of ResTarget) */
+} RPCommonSyntax;
+
 /*
  * WindowDef - raw representation of WINDOW and OVER clauses
  *
@@ -555,6 +593,8 @@ typedef struct WindowDef
 	char	   *refname;		/* referenced window name, if any */
 	List	   *partitionClause;	/* PARTITION BY expression list */
 	List	   *orderClause;	/* ORDER BY (list of SortBy) */
+	List	   *rowPatternMeasures;	/* row pattern measures (list of ResTarget) */
+	RPCommonSyntax *rpCommonSyntax;	/* row pattern common syntax */
 	int			frameOptions;	/* frame_clause options, see below */
 	Node	   *startOffset;	/* expression for starting bound, if any */
 	Node	   *endOffset;		/* expression for ending bound, if any */
@@ -1476,6 +1516,11 @@ typedef struct GroupingSet
  * the orderClause might or might not be copied (see copiedOrder); the framing
  * options are never copied, per spec.
  *
+ * "defineClause" is Row Pattern Recognition DEFINE clause (list of
+ * TargetEntry). TargetEntry.resname represents row pattern definition
+ * variable name. "patternVariable" and "patternRegexp" represents PATTERN
+ * clause.
+ *
  * The information relevant for the query jumbling is the partition clause
  * type and its bounds.
  */
@@ -1507,6 +1552,17 @@ typedef struct WindowClause
 	Index		winref;			/* ID referenced by window functions */
 	/* did we copy orderClause from refname? */
 	bool		copiedOrder pg_node_attr(query_jumble_ignore);
+	/* Row Pattern AFTER MACH SKIP clause */
+	RPSkipTo	rpSkipTo;		/* Row Pattern Skip To type */
+	bool		initial;		/* true if <row pattern initial or seek> is initial */
+	/* Row Pattern DEFINE clause (list of TargetEntry) */
+	List		*defineClause;
+	/* Row Pattern DEFINE variable initial names (list of String) */
+	List		*defineInitial;
+	/* Row Pattern PATTERN variable name (list of String) */
+	List		*patternVariable;
+	/* Row Pattern PATTERN regular expression quantifier ('+' or ''. list of String) */
+	List		*patternRegexp;
 } WindowClause;
 
 /*
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 5984dcfa4b..2804333b53 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -128,6 +128,7 @@ PG_KEYWORD("default", DEFAULT, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("defaults", DEFAULTS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("deferrable", DEFERRABLE, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("deferred", DEFERRED, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("define", DEFINE, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("definer", DEFINER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("delete", DELETE_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("delimiter", DELIMITER, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -212,6 +213,7 @@ PG_KEYWORD("index", INDEX, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("indexes", INDEXES, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("inherit", INHERIT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("inherits", INHERITS, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("initial", INITIAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("initially", INITIALLY, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("inline", INLINE_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("inner", INNER_P, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
@@ -265,6 +267,7 @@ PG_KEYWORD("match", MATCH, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("matched", MATCHED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("materialized", MATERIALIZED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("maxvalue", MAXVALUE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("measures", MEASURES, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("merge", MERGE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("method", METHOD, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("minute", MINUTE_P, UNRESERVED_KEYWORD, AS_LABEL)
@@ -326,6 +329,9 @@ PG_KEYWORD("partial", PARTIAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("partition", PARTITION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("passing", PASSING, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("password", PASSWORD, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("past", PAST, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("pattern", PATTERN_P, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("permute", PERMUTE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("placing", PLACING, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("plans", PLANS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("policy", POLICY, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -385,6 +391,7 @@ PG_KEYWORD("scroll", SCROLL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("search", SEARCH, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("second", SECOND_P, UNRESERVED_KEYWORD, AS_LABEL)
 PG_KEYWORD("security", SECURITY, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("seek", SEEK, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("select", SELECT, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("sequence", SEQUENCE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("sequences", SEQUENCES, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -416,6 +423,7 @@ PG_KEYWORD("stored", STORED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("strict", STRICT_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("strip", STRIP_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("subscription", SUBSCRIPTION, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("subset", SUBSET, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("substring", SUBSTRING, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("support", SUPPORT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("symmetric", SYMMETRIC, RESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index f589112d5e..6640090910 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -51,6 +51,7 @@ typedef enum ParseExprKind
 	EXPR_KIND_WINDOW_FRAME_RANGE,	/* window frame clause with RANGE */
 	EXPR_KIND_WINDOW_FRAME_ROWS,	/* window frame clause with ROWS */
 	EXPR_KIND_WINDOW_FRAME_GROUPS,	/* window frame clause with GROUPS */
+	EXPR_KIND_RPR_DEFINE,		/* DEFINE */
 	EXPR_KIND_SELECT_TARGET,	/* SELECT target list item */
 	EXPR_KIND_INSERT_TARGET,	/* INSERT target list item */
 	EXPR_KIND_UPDATE_SOURCE,	/* UPDATE assignment source item */
-- 
2.25.1


----Next_Part(Fri_Dec__8_10_16_13_2023_489)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
 filename="v12-0002-Row-pattern-recognition-patch-parse-analysis.patch"



^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--





^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread

* [PATCH] Restructure repack worker teardown
@ 2026-05-18 17:13 Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 496+ messages in thread

From: Álvaro Herrera @ 2026-05-18 17:13 UTC (permalink / raw)

The original code would leave a shared memory segment unreleased if we
fail partway through initialization.  Change the shutdown order so that
we already free it.

Author: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
 src/backend/commands/repack.c | 67 ++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index bfc62c8f752..c9064d8fd13 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -3411,10 +3411,14 @@ start_repack_decoding_worker(Oid relid)
 	shm_mq_handle *mqh;
 	BackgroundWorker bgw;
 
+	decoding_worker = palloc0_object(DecodingWorker);
+
 	/* Setup shared memory. */
 	size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
 		BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
 	seg = dsm_create(size, 0);
+	decoding_worker->seg = seg;
+
 	shared = (DecodingWorkerShared *) dsm_segment_address(seg);
 	shared->initialized = false;
 	shared->lsn_upto = InvalidXLogRecPtr;
@@ -3454,14 +3458,12 @@ start_repack_decoding_worker(Oid relid)
 	bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
 	bgw.bgw_notify_pid = MyProcPid;
 
-	decoding_worker = palloc0_object(DecodingWorker);
 	if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
 		ereport(ERROR,
 				errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
 				errmsg("out of background worker slots"),
 				errhint("You might need to increase \"%s\".", "max_worker_processes"));
 
-	decoding_worker->seg = seg;
 	decoding_worker->error_mqh = mqh;
 
 	/*
@@ -3487,17 +3489,6 @@ start_repack_decoding_worker(Oid relid)
 	ConditionVariableCancelSleep();
 }
 
-/*
- * PG_ENSURE_ERROR_CLEANUP callback to stop the decoding worker.
- * This ensures the worker is terminated on both ERROR and FATAL exits,
- * unlike PG_FINALLY which only handles ERROR.
- */
-static void
-repack_decoding_worker_cleanup_cb(int code, Datum arg)
-{
-	stop_repack_decoding_worker();
-}
-
 /*
  * Stop the decoding worker and cleanup the related resources.
  *
@@ -3508,39 +3499,43 @@ static void
 stop_repack_decoding_worker(void)
 {
 	BgwHandleStatus status;
+	dsm_segment	   *dsmseg;
 
-	/* Haven't reached the worker startup? */
+	/* Nothing to do if no worker was set up. */
 	if (decoding_worker == NULL)
 		return;
 
-	/* Could not register the worker? */
-	if (decoding_worker->handle == NULL)
-		return;
+	/* Terminate the worker process, if one is running. */
+	if (decoding_worker->handle != NULL)
+	{
+		TerminateBackgroundWorker(decoding_worker->handle);
+		/* The worker should really exit before the REPACK command does. */
+		HOLD_INTERRUPTS();
+		status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+		RESUME_INTERRUPTS();
 
-	TerminateBackgroundWorker(decoding_worker->handle);
-	/* The worker should really exit before the REPACK command does. */
-	HOLD_INTERRUPTS();
-	status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
-	RESUME_INTERRUPTS();
-
-	if (status == BGWH_POSTMASTER_DIED)
-		ereport(FATAL,
-				errcode(ERRCODE_ADMIN_SHUTDOWN),
-				errmsg("postmaster exited during REPACK command"));
-
-	shm_mq_detach(decoding_worker->error_mqh);
+		if (status == BGWH_POSTMASTER_DIED)
+			ereport(FATAL,
+					errcode(ERRCODE_ADMIN_SHUTDOWN),
+					errmsg("postmaster exited during REPACK command"));
+	}
 
 	/*
-	 * If we could not cancel the current sleep due to ERROR, do that before
-	 * we detach from the shared memory the condition variable is located in.
-	 * If we did not, the bgworker ERROR handling code would try and fail
-	 * badly.
+	 * Now detach from our shared memory segment.  In error cases there might
+	 * still be messages from the worker in the queue, which ProcessInterrupts
+	 * would try to read; this is pointless (and causes an assertion failure),
+	 * so set the global pointer to NULL to have ProcessRepackMessages ignore
+	 * them.
 	 */
-	ConditionVariableCancelSleep();
-
-	dsm_detach(decoding_worker->seg);
+	dsmseg = decoding_worker->seg;
 	pfree(decoding_worker);
 	decoding_worker = NULL;
+
+	/* We must also cancel the current sleep, if one is still set up */
+	ConditionVariableCancelSleep();
+
+	if (dsmseg != NULL)
+		dsm_detach(dsmseg);
 }
 
 /* stop_repack_decoding_worker, wrapped as a before_shmem_exit callback */
-- 
2.47.3


--b42ct6adeyjj4cbm--






^ permalink  raw  reply  [nested|flat] 496+ messages in thread