From 48412fcfb708eb990136321686681e961626aabe Mon Sep 17 00:00:00 2001 From: Lukas Fittl Date: Thu, 2 Jan 2025 10:46:30 -0800 Subject: [PATCH v3] Add pgstat_drop_matching_entries() This allows users of the cumulative statistics systems to drop all entries based on the decisions of a matching function, similar to how pgstat_reset_matching_entries() works. --- src/include/utils/pgstat_internal.h | 2 ++ src/backend/utils/activity/pgstat_shmem.c | 31 ++++++++++++++++++- .../injection_points--1.0.sql | 10 ++++++ .../injection_points/injection_stats.c | 19 ++++++++++++ .../modules/injection_points/t/001_stats.pl | 13 ++++++++ 5 files changed, 74 insertions(+), 1 deletion(-) diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index a3d39d2b725..06dcea3f0dc 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -718,6 +718,8 @@ extern bool pgstat_lock_entry_shared(PgStat_EntryRef *entry_ref, bool nowait); extern void pgstat_unlock_entry(PgStat_EntryRef *entry_ref); extern bool pgstat_drop_entry(PgStat_Kind kind, Oid dboid, uint64 objid); extern void pgstat_drop_all_entries(void); +extern void pgstat_drop_matching_entries(bool (*do_drop) (PgStatShared_HashEntry *, Datum), + Datum match_data); extern PgStat_EntryRef *pgstat_get_entry_ref_locked(PgStat_Kind kind, Oid dboid, uint64 objid, bool nowait); extern void pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts); diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c index 342586397d6..770d62425c5 100644 --- a/src/backend/utils/activity/pgstat_shmem.c +++ b/src/backend/utils/activity/pgstat_shmem.c @@ -993,19 +993,39 @@ pgstat_drop_entry(PgStat_Kind kind, Oid dboid, uint64 objid) return freed; } +/* + * Scan through the shared hashtable of stats, dropping statistics if + * approved by the optional do_drop() function. + */ void -pgstat_drop_all_entries(void) +pgstat_drop_matching_entries(bool (*do_drop) (PgStatShared_HashEntry *, Datum), + Datum match_data) { dshash_seq_status hstat; PgStatShared_HashEntry *ps; uint64 not_freed_count = 0; + /* entries are removed, take an exclusive lock */ dshash_seq_init(&hstat, pgStatLocal.shared_hash, true); while ((ps = dshash_seq_next(&hstat)) != NULL) { if (ps->dropped) continue; + if (do_drop != NULL && !do_drop(ps, match_data)) + continue; + + /* delete local reference */ + if (pgStatEntryRefHash) + { + PgStat_EntryRefHashEntry *lohashent = + pgstat_entry_ref_hash_lookup(pgStatEntryRefHash, ps->key); + + if (lohashent) + pgstat_release_entry_ref(lohashent->key, lohashent->entry_ref, + true); + } + if (!pgstat_drop_entry_internal(ps, &hstat)) not_freed_count++; } @@ -1015,6 +1035,15 @@ pgstat_drop_all_entries(void) pgstat_request_entry_refs_gc(); } +/* + * Scan through the shared hashtable of stats and drop all entries. + */ +void +pgstat_drop_all_entries(void) +{ + pgstat_drop_matching_entries(NULL, 0); +} + static void shared_stat_reset_contents(PgStat_Kind kind, PgStatShared_Common *header, TimestampTz ts) diff --git a/src/test/modules/injection_points/injection_points--1.0.sql b/src/test/modules/injection_points/injection_points--1.0.sql index c445bf64e62..5d83f08811b 100644 --- a/src/test/modules/injection_points/injection_points--1.0.sql +++ b/src/test/modules/injection_points/injection_points--1.0.sql @@ -85,6 +85,16 @@ RETURNS bigint AS 'MODULE_PATHNAME', 'injection_points_stats_numcalls' LANGUAGE C STRICT; +-- +-- injection_points_stats_drop() +-- +-- Drop all statistics of injection points. +-- +CREATE FUNCTION injection_points_stats_drop() +RETURNS void +AS 'MODULE_PATHNAME', 'injection_points_stats_drop' +LANGUAGE C STRICT; + -- -- injection_points_stats_fixed() -- diff --git a/src/test/modules/injection_points/injection_stats.c b/src/test/modules/injection_points/injection_stats.c index 5db62bca66f..14903c629e0 100644 --- a/src/test/modules/injection_points/injection_stats.c +++ b/src/test/modules/injection_points/injection_stats.c @@ -197,3 +197,22 @@ injection_points_stats_numcalls(PG_FUNCTION_ARGS) PG_RETURN_INT64(entry->numcalls); } + +/* Only used by injection_points_stats_drop() */ +static bool +match_inj_entries(PgStatShared_HashEntry *entry, Datum match_data) +{ + return entry->key.kind == PGSTAT_KIND_INJECTION; +} + +/* + * SQL function that drops all injection point statistics. + */ +PG_FUNCTION_INFO_V1(injection_points_stats_drop); +Datum +injection_points_stats_drop(PG_FUNCTION_ARGS) +{ + pgstat_drop_matching_entries(match_inj_entries, 0); + + PG_RETURN_VOID(); +} diff --git a/src/test/modules/injection_points/t/001_stats.pl b/src/test/modules/injection_points/t/001_stats.pl index d4539fe8727..25de5fc46fe 100644 --- a/src/test/modules/injection_points/t/001_stats.pl +++ b/src/test/modules/injection_points/t/001_stats.pl @@ -69,6 +69,19 @@ $fixedstats = $node->safe_psql('postgres', "SELECT * FROM injection_points_stats_fixed();"); is($fixedstats, '0|0|0|0|0', 'fixed stats after crash'); +# On drop all stats are gone +$node->safe_psql('postgres', + "SELECT injection_points_attach('stats-notice', 'notice');"); +$node->safe_psql('postgres', "SELECT injection_points_run('stats-notice');"); +$node->safe_psql('postgres', "SELECT injection_points_run('stats-notice');"); +$numcalls = $node->safe_psql('postgres', + "SELECT injection_points_stats_numcalls('stats-notice');"); +is($numcalls, '2', 'number of stats calls'); +$node->safe_psql('postgres', "SELECT injection_points_stats_drop();"); +$numcalls = $node->safe_psql('postgres', + "SELECT injection_points_stats_numcalls('stats-notice');"); +is($numcalls, '', 'no stats after drop via SQL function'); + # Stop the server, disable the module, then restart. The server # should be able to come up. $node->stop; -- 2.47.2