From dbe13b3d61c03f5d8d6773021e87c626ab04b3b0 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 29 Dec 2025 11:39:56 +0900 Subject: [PATCH v14 1/3] Rework GetMultiXactInfo() This routine returned a number of offsets as a MultiXactOffset, but it is not actually an offset, just a number to define their range. This was confusing. This type confusion comes from the original implementation of MultiXactMemberFreezeThreshold(). --- src/include/access/multixact.h | 2 +- src/backend/access/transam/multixact.c | 16 ++++++++-------- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h index 6433fe163641..d22abbb72512 100644 --- a/src/include/access/multixact.h +++ b/src/include/access/multixact.h @@ -109,7 +109,7 @@ extern bool MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly); extern void MultiXactIdSetOldestMember(void); extern int GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members, bool from_pgupgrade, bool isLockOnly); -extern void GetMultiXactInfo(uint32 *multixacts, MultiXactOffset *members, +extern void GetMultiXactInfo(uint32 *multixacts, MultiXactOffset *nextOffset, MultiXactId *oldestMultiXactId, MultiXactOffset *oldestOffset); extern bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2); diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c index 34956a5a6634..0d6f594e2a06 100644 --- a/src/backend/access/transam/multixact.c +++ b/src/backend/access/transam/multixact.c @@ -2461,25 +2461,23 @@ find_multixact_start(MultiXactId multi, MultiXactOffset *result) * * Returns information about the current MultiXact state, as of: * multixacts: Number of MultiXacts (nextMultiXactId - oldestMultiXactId) - * members: Number of member entries (nextOffset - oldestOffset) + * nextOffset: Next-to-be-assigned offset * oldestMultiXactId: Oldest MultiXact ID still in use * oldestOffset: Oldest offset still in use */ void -GetMultiXactInfo(uint32 *multixacts, MultiXactOffset *members, +GetMultiXactInfo(uint32 *multixacts, MultiXactOffset *nextOffset, MultiXactId *oldestMultiXactId, MultiXactOffset *oldestOffset) { - MultiXactOffset nextOffset; MultiXactId nextMultiXactId; LWLockAcquire(MultiXactGenLock, LW_SHARED); - nextOffset = MultiXactState->nextOffset; + *nextOffset = MultiXactState->nextOffset; *oldestMultiXactId = MultiXactState->oldestMultiXactId; nextMultiXactId = MultiXactState->nextMXact; *oldestOffset = MultiXactState->oldestOffset; LWLockRelease(MultiXactGenLock); - *members = nextOffset - *oldestOffset; *multixacts = nextMultiXactId - *oldestMultiXactId; } @@ -2514,16 +2512,18 @@ GetMultiXactInfo(uint32 *multixacts, MultiXactOffset *members, int MultiXactMemberFreezeThreshold(void) { - MultiXactOffset members; uint32 multixacts; uint32 victim_multixacts; double fraction; int result; MultiXactId oldestMultiXactId; MultiXactOffset oldestOffset; + MultiXactOffset nextOffset; + uint64 members; - /* Read the current offsets and members usage. */ - GetMultiXactInfo(&multixacts, &members, &oldestMultiXactId, &oldestOffset); + /* Read the current offsets and multixact usage. */ + GetMultiXactInfo(&multixacts, &nextOffset, &oldestMultiXactId, &oldestOffset); + members = nextOffset - oldestOffset; /* If member space utilization is low, no special action is required. */ if (members <= MULTIXACT_MEMBER_LOW_THRESHOLD) -- 2.51.0