From 1e41a5155fb689f1d4ae8a5cfb244b824e913bae Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 3 Sep 2024 10:38:15 +0900 Subject: [PATCH] Add callback for backend initialization in pgstats This is currently used by the WAL stats, and is now made available for others as well. --- src/include/utils/pgstat_internal.h | 7 +++++++ src/backend/utils/activity/pgstat.c | 14 ++++++++++++-- src/backend/utils/activity/pgstat_wal.c | 2 +- 3 files changed, 20 insertions(+), 3 deletions(-) diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index fb132e439d..53f7d5c98c 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -229,6 +229,12 @@ typedef struct PgStat_KindInfo */ uint32 pending_size; + /* + * Perform custom actions when initializing a backend (standalone or under + * postmaster). Optional. + */ + void (*init_backend_cb) (void); + /* * For variable-numbered stats: flush pending stats. Required if pending * data is used. @@ -676,6 +682,7 @@ extern bool pgstat_flush_wal(bool nowait); extern void pgstat_init_wal(void); extern bool pgstat_have_pending_wal(void); +extern void pgstat_wal_init_backend_cb(void); extern void pgstat_wal_init_shmem_cb(void *stats); extern void pgstat_wal_reset_all_cb(TimestampTz ts); extern void pgstat_wal_snapshot_cb(void); diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c index b2ca3f39b7..3b6983ff5d 100644 --- a/src/backend/utils/activity/pgstat.c +++ b/src/backend/utils/activity/pgstat.c @@ -441,6 +441,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .shared_data_off = offsetof(PgStatShared_Wal, stats), .shared_data_len = sizeof(((PgStatShared_Wal *) 0)->stats), + .init_backend_cb = pgstat_wal_init_backend_cb, .init_shmem_cb = pgstat_wal_init_shmem_cb, .reset_all_cb = pgstat_wal_reset_all_cb, .snapshot_cb = pgstat_wal_snapshot_cb, @@ -604,10 +605,19 @@ pgstat_initialize(void) pgstat_attach_shmem(); - pgstat_init_wal(); - pgstat_init_snapshot_fixed(); + /* Backend initialization callbacks */ + for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++) + { + const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind); + + if (kind_info == NULL || kind_info->init_backend_cb == NULL) + continue; + + kind_info->init_backend_cb(); + } + /* Set up a process-exit hook to clean up */ before_shmem_exit(pgstat_shutdown_hook, 0); diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c index e2a3f6b865..8c19c3f2fd 100644 --- a/src/backend/utils/activity/pgstat_wal.c +++ b/src/backend/utils/activity/pgstat_wal.c @@ -138,7 +138,7 @@ pgstat_flush_wal(bool nowait) } void -pgstat_init_wal(void) +pgstat_wal_init_backend_cb(void) { /* * Initialize prevWalUsage with pgWalUsage so that pgstat_flush_wal() can -- 2.45.2