From 5b63794f4ae24a940aef1238ba503c51b0ee393a Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Thu, 19 Mar 2026 11:57:02 +0200 Subject: [PATCH v6 5/6] move pgss shmem_startup hook code into the new init_fn callback --- .../pg_stat_statements/pg_stat_statements.c | 56 +++++++++---------- 1 file changed, 26 insertions(+), 30 deletions(-) diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c index 8df4749a43b..8c84232f4d0 100644 --- a/contrib/pg_stat_statements/pg_stat_statements.c +++ b/contrib/pg_stat_statements/pg_stat_statements.c @@ -292,7 +292,6 @@ static ShmemHashDesc pgssSharedHashDesc = static int nesting_level = 0; /* Saved hook values */ -static shmem_startup_hook_type prev_shmem_startup_hook = NULL; static post_parse_analyze_hook_type prev_post_parse_analyze_hook = NULL; static planner_hook_type prev_planner_hook = NULL; static ExecutorStart_hook_type prev_ExecutorStart = NULL; @@ -353,7 +352,6 @@ PG_FUNCTION_INFO_V1(pg_stat_statements_1_13); PG_FUNCTION_INFO_V1(pg_stat_statements); PG_FUNCTION_INFO_V1(pg_stat_statements_info); -static void pgss_shmem_startup(void); static void pgss_shmem_shutdown(int code, Datum arg); static void pgss_post_parse_analyze(ParseState *pstate, Query *query, JumbleState *jstate); @@ -492,19 +490,18 @@ _PG_init(void) MarkGUCPrefixReserved("pg_stat_statements"); /* - * Register our shared memory needs, including hash table + * Register our shared memory needs. Register the hash table first, so + * that it's already initialized when pgss_shmem_init() is called. */ - ShmemRegisterStruct(&pgssSharedStateShmemDesc); - pgssSharedHashDesc.init_size = pgss_max; pgssSharedHashDesc.max_size = pgss_max; ShmemRegisterHash(&pgssSharedHashDesc); + ShmemRegisterStruct(&pgssSharedStateShmemDesc); + /* * Install hooks. */ - prev_shmem_startup_hook = shmem_startup_hook; - shmem_startup_hook = pgss_shmem_startup; prev_post_parse_analyze_hook = post_parse_analyze_hook; post_parse_analyze_hook = pgss_post_parse_analyze; prev_planner_hook = planner_hook; @@ -521,11 +518,29 @@ _PG_init(void) ProcessUtility_hook = pgss_ProcessUtility; } +/* + * Initialize our shared memory data structures at postmaster startup. + * + * Load any pre-existing statistics from file. Also create and load the + * query-texts file, which is expected to exist (even if empty) while the + * module is enabled. + */ static void pgss_shmem_init(void *arg) { int tranche_id; + FILE *file = NULL; + FILE *qfile = NULL; + uint32 header; + int32 num; + int32 pgver; + int32 i; + int buffer_size; + char *buffer = NULL; + /* + * Initialize the shmem area with no statistics. + */ tranche_id = LWLockNewTrancheId("pg_stat_statements"); LWLockInitialize(&pgss->lock.lock, tranche_id); pgss->cur_median_usage = ASSUMED_MEDIAN_INIT; @@ -536,30 +551,9 @@ pgss_shmem_init(void *arg) pgss->gc_count = 0; pgss->stats.dealloc = 0; pgss->stats.stats_reset = GetCurrentTimestamp(); -} - -/* - * shmem_startup hook: Load any pre-existing statistics from file at - * postmaster startup. Also create and load the query-texts file, which is - * expected to exist (even if empty) while the module is enabled. - */ -static void -pgss_shmem_startup(void) -{ - FILE *file = NULL; - FILE *qfile = NULL; - uint32 header; - int32 num; - int32 pgver; - int32 i; - int buffer_size; - char *buffer = NULL; - if (prev_shmem_startup_hook) - prev_shmem_startup_hook(); - - if (IsUnderPostmaster) - return; /* nothing to do in backends */ + /* The hash table must be initialized already */ + Assert(pgss_hash != NULL); /* * Set up a shmem exit hook to dump the statistics to disk on postmaster @@ -568,6 +562,8 @@ pgss_shmem_startup(void) on_shmem_exit(pgss_shmem_shutdown, (Datum) 0); /* + * Load any pre-existing statistics from file. + * * Note: we don't bother with locks here, because there should be no other * processes running when this code is reached. */ -- 2.47.3