diff options
Diffstat (limited to 'src/backend/access/transam/multixact.c')
| -rw-r--r-- | src/backend/access/transam/multixact.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c index 05e1dcb49c5..55a8ca7ac49 100644 --- a/src/backend/access/transam/multixact.c +++ b/src/backend/access/transam/multixact.c @@ -289,7 +289,6 @@ static MemoryContext MXactContext = NULL; /* internal MultiXactId management */ static void MultiXactIdSetOldestVisible(void); -static MultiXactId CreateMultiXactId(int nmembers, MultiXactMember *members); static void RecordNewMultiXact(MultiXactId multi, MultiXactOffset offset, int nmembers, MultiXactMember *members); static MultiXactId GetNewMultiXactId(int nmembers, MultiXactOffset *offset); @@ -336,6 +335,9 @@ MultiXactIdCreate(TransactionId xid1, MultiXactStatus status1, Assert(!TransactionIdEquals(xid1, xid2) || (status1 != status2)); + /* MultiXactIdSetOldestMember() must have been called already. */ + Assert(MultiXactIdIsValid(OldestMemberMXactId[MyBackendId])); + /* * Note: unlike MultiXactIdExpand, we don't bother to check that both XIDs * are still running. In typical usage, xid2 will be our own XID and the @@ -347,7 +349,7 @@ MultiXactIdCreate(TransactionId xid1, MultiXactStatus status1, members[1].xid = xid2; members[1].status = status2; - newMulti = CreateMultiXactId(2, members); + newMulti = MultiXactIdCreateFromMembers(2, members); debug_elog3(DEBUG2, "Create: %s", mxid_to_string(newMulti, 2, members)); @@ -387,6 +389,9 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status) AssertArg(MultiXactIdIsValid(multi)); AssertArg(TransactionIdIsValid(xid)); + /* MultiXactIdSetOldestMember() must have been called already. */ + Assert(MultiXactIdIsValid(OldestMemberMXactId[MyBackendId])); + debug_elog5(DEBUG2, "Expand: received multi %u, xid %u status %s", multi, xid, mxstatus_to_string(status)); @@ -410,7 +415,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status) */ member.xid = xid; member.status = status; - newMulti = CreateMultiXactId(1, &member); + newMulti = MultiXactIdCreateFromMembers(1, &member); debug_elog4(DEBUG2, "Expand: %u has no members, create singleton %u", multi, newMulti); @@ -462,7 +467,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status) newMembers[j].xid = xid; newMembers[j++].status = status; - newMulti = CreateMultiXactId(j, newMembers); + newMulti = MultiXactIdCreateFromMembers(j, newMembers); pfree(members); pfree(newMembers); @@ -667,16 +672,16 @@ ReadNextMultiXactId(void) } /* - * CreateMultiXactId - * Make a new MultiXactId + * MultiXactIdCreateFromMembers + * Make a new MultiXactId from the specified set of members * * Make XLOG, SLRU and cache entries for a new MultiXactId, recording the * given TransactionIds as members. Returns the newly created MultiXactId. * * NB: the passed members[] array will be sorted in-place. */ -static MultiXactId -CreateMultiXactId(int nmembers, MultiXactMember *members) +MultiXactId +MultiXactIdCreateFromMembers(int nmembers, MultiXactMember *members) { MultiXactId multi; MultiXactOffset offset; @@ -707,6 +712,13 @@ CreateMultiXactId(int nmembers, MultiXactMember *members) * Assign the MXID and offsets range to use, and make sure there is space * in the OFFSETs and MEMBERs files. NB: this routine does * START_CRIT_SECTION(). + * + * Note: unlike MultiXactIdCreate and MultiXactIdExpand, we do not check + * that we've called MultiXactIdSetOldestMember here. This is because + * this routine is used in some places to create new MultiXactIds of which + * the current backend is not a member, notably during freezing of multis + * in vacuum. During vacuum, in particular, it would be unacceptable to + * keep OldestMulti set, in case it runs for long. */ multi = GetNewMultiXactId(nmembers, &offset); @@ -763,7 +775,8 @@ CreateMultiXactId(int nmembers, MultiXactMember *members) * RecordNewMultiXact * Write info about a new multixact into the offsets and members files * - * This is broken out of CreateMultiXactId so that xlog replay can use it. + * This is broken out of MultiXactIdCreateFromMembers so that xlog replay can + * use it. */ static void RecordNewMultiXact(MultiXactId multi, MultiXactOffset offset, @@ -867,9 +880,6 @@ GetNewMultiXactId(int nmembers, MultiXactOffset *offset) debug_elog3(DEBUG2, "GetNew: for %d xids", nmembers); - /* MultiXactIdSetOldestMember() must have been called already */ - Assert(MultiXactIdIsValid(OldestMemberMXactId[MyBackendId])); - /* safety check, we should never get this far in a HS slave */ if (RecoveryInProgress()) elog(ERROR, "cannot assign MultiXactIds during recovery"); |