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| author | Alvaro Herrera <alvherre@alvh.no-ip.org> | 2015-01-04 15:48:29 -0300 |
|---|---|---|
| committer | Alvaro Herrera <alvherre@alvh.no-ip.org> | 2015-01-04 15:48:29 -0300 |
| commit | d5e3d1e969d2f65009f718d3100d6565f47f9112 (patch) | |
| tree | f716939d49365528b4165697a1b59696b868da1f /src/backend | |
| parent | 2ea95959afa225118374ab1691a5ccf84ae05ce8 (diff) | |
| download | postgresql-d5e3d1e969d2f65009f718d3100d6565f47f9112.tar.gz postgresql-d5e3d1e969d2f65009f718d3100d6565f47f9112.zip | |
Fix thinko in lock mode enum
Commit 0e5680f4737a9c6aa94aa9e77543e5de60411322 contained a thinko
mixing LOCKMODE with LockTupleMode. This caused misbehavior in the case
where a tuple is marked with a multixact with at most a FOR SHARE lock,
and another transaction tries to acquire a FOR NO KEY EXCLUSIVE lock;
this case should block but doesn't.
Include a new isolation tester spec file to explicitely try all the
tuple lock combinations; without the fix it shows the problem:
starting permutation: s1_begin s1_lcksvpt s1_tuplock2 s2_tuplock3 s1_commit
step s1_begin: BEGIN;
step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
a
1
step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
a
1
step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
a
1
step s1_commit: COMMIT;
With the fixed code, step s2_tuplock3 blocks until session 1 commits,
which is the correct behavior.
All other cases behave correctly.
Backpatch to 9.3, like the commit that introduced the problem.
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index cd4cc981135..24e300ca001 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -6102,6 +6102,7 @@ DoesMultiXactIdConflict(MultiXactId multi, uint16 infomask, int nmembers; MultiXactMember *members; bool result = false; + LOCKMODE wanted = tupleLockExtraInfo[lockmode].hwlock; allow_old = !(infomask & HEAP_LOCK_MASK) && HEAP_XMAX_IS_LOCKED_ONLY(infomask); nmembers = GetMultiXactIdMembers(multi, &members, allow_old, @@ -6113,11 +6114,12 @@ DoesMultiXactIdConflict(MultiXactId multi, uint16 infomask, for (i = 0; i < nmembers; i++) { TransactionId memxid; - LockTupleMode memlockmode; + LOCKMODE memlockmode; memlockmode = LOCKMODE_from_mxstatus(members[i].status); + /* ignore members that don't conflict with the lock we want */ - if (!DoLockModesConflict(memlockmode, lockmode)) + if (!DoLockModesConflict(memlockmode, wanted)) continue; /* ignore members from current xact */ |