From 104ab93d761746366d6e71e84472f3a3264e7a5b Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Thu, 11 Sep 2025 11:50:18 +0900 Subject: [PATCH] Document no-padding rule for PgStat_HashKey This removes a couple of memset(0) calls, as we don't want padding in it. --- src/include/utils/pgstat_internal.h | 6 +++++- src/backend/utils/activity/pgstat.c | 5 +---- src/backend/utils/activity/pgstat_shmem.c | 10 ++-------- 3 files changed, 8 insertions(+), 13 deletions(-) diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index 6cf00008f633..b62747a3ba05 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -48,7 +48,11 @@ * PgStatShared_Common as the first element. */ -/* struct for shared statistics hash entry key. */ +/* + * Struct for shared statistics hash entry key. + * + * NB: We assume that this struct contains no padding. + */ typedef struct PgStat_HashKey { PgStat_Kind kind; /* statistics entry kind */ diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c index f8e91484e36b..73c2ced3f4e2 100644 --- a/src/backend/utils/activity/pgstat.c +++ b/src/backend/utils/activity/pgstat.c @@ -932,7 +932,7 @@ pgstat_clear_snapshot(void) void * pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid) { - PgStat_HashKey key; + PgStat_HashKey key = {0}; PgStat_EntryRef *entry_ref; void *stats_data; const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind); @@ -943,9 +943,6 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid) pgstat_prep_snapshot(); - /* clear padding */ - memset(&key, 0, sizeof(struct PgStat_HashKey)); - key.kind = kind; key.dboid = dboid; key.objid = objid; diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c index 9dc3212f7dd0..ca36fd247f64 100644 --- a/src/backend/utils/activity/pgstat_shmem.c +++ b/src/backend/utils/activity/pgstat_shmem.c @@ -456,14 +456,11 @@ PgStat_EntryRef * pgstat_get_entry_ref(PgStat_Kind kind, Oid dboid, uint64 objid, bool create, bool *created_entry) { - PgStat_HashKey key; + PgStat_HashKey key = {0}; PgStatShared_HashEntry *shhashent; PgStatShared_Common *shheader = NULL; PgStat_EntryRef *entry_ref; - /* clear padding */ - memset(&key, 0, sizeof(struct PgStat_HashKey)); - key.kind = kind; key.dboid = dboid; key.objid = objid; @@ -988,13 +985,10 @@ pgstat_drop_database_and_contents(Oid dboid) bool pgstat_drop_entry(PgStat_Kind kind, Oid dboid, uint64 objid) { - PgStat_HashKey key; + PgStat_HashKey key = {0}; PgStatShared_HashEntry *shent; bool freed = true; - /* clear padding */ - memset(&key, 0, sizeof(struct PgStat_HashKey)); - key.kind = kind; key.dboid = dboid; key.objid = objid; -- 2.51.0