diff options
Diffstat (limited to 'src/backend/utils/cache/relcache.c')
| -rw-r--r-- | src/backend/utils/cache/relcache.c | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index 42b500ac2b2..bbbb609d2e9 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -1957,7 +1957,9 @@ RelationClearRelation(Relation relation, bool rebuild) { /* * As per notes above, a rel to be rebuilt MUST have refcnt > 0; while of - * course it would be a bad idea to blow away one with nonzero refcnt. + * course it would be an equally bad idea to blow away one with nonzero + * refcnt, since that would leave someone somewhere with a dangling + * pointer. All callers are expected to have verified that this holds. */ Assert(rebuild ? !RelationHasReferenceCountZero(relation) : @@ -2559,11 +2561,25 @@ AtEOXact_cleanup(Relation relation, bool isCommit) { if (isCommit) relation->rd_createSubid = InvalidSubTransactionId; - else + else if (RelationHasReferenceCountZero(relation)) { RelationClearRelation(relation, false); return; } + else + { + /* + * Hmm, somewhere there's a (leaked?) reference to the relation. + * We daren't remove the entry for fear of dereferencing a + * dangling pointer later. Bleat, and mark it as not belonging to + * the current transaction. Hopefully it'll get cleaned up + * eventually. This must be just a WARNING to avoid + * error-during-error-recovery loops. + */ + relation->rd_createSubid = InvalidSubTransactionId; + elog(WARNING, "cannot remove relcache entry for \"%s\" because it has nonzero refcount", + RelationGetRelationName(relation)); + } } /* @@ -2652,11 +2668,24 @@ AtEOSubXact_cleanup(Relation relation, bool isCommit, { if (isCommit) relation->rd_createSubid = parentSubid; - else + else if (RelationHasReferenceCountZero(relation)) { RelationClearRelation(relation, false); return; } + else + { + /* + * Hmm, somewhere there's a (leaked?) reference to the relation. + * We daren't remove the entry for fear of dereferencing a + * dangling pointer later. Bleat, and transfer it to the parent + * subtransaction so we can try again later. This must be just a + * WARNING to avoid error-during-error-recovery loops. + */ + relation->rd_createSubid = parentSubid; + elog(WARNING, "cannot remove relcache entry for \"%s\" because it has nonzero refcount", + RelationGetRelationName(relation)); + } } /* |