diff options
| author | Noah Misch <noah@leadboat.com> | 2024-10-29 09:39:55 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2024-10-29 09:40:00 -0700 |
| commit | c2139db11b161096c9d65a0fa7c1a8a3227ea856 (patch) | |
| tree | 8ba305f45f9292a5eff50d9ff6ef6229ceb931ec /src/backend/access/heap/heapam.c | |
| parent | 8f1759c9b4ee8e69ee6630d7f8f1be1e2876f36e (diff) | |
Unpin buffer before inplace update waits for an XID to end.
Commit a07e03fd8fa7daf4d1356f7cb501ffe784ea6257 changed inplace updates
to wait for heap_update() commands like GRANT TABLE and GRANT DATABASE.
By keeping the pin during that wait, a sequence of autovacuum workers
and an uncommitted GRANT starved one foreground LockBufferForCleanup()
for six minutes, on buildfarm member sarus. Prevent, at the cost of a
bit of complexity. Back-patch to v12, like the earlier commit. That
commit and heap_inplace_lock() have not yet appeared in any release.
Discussion: https://postgr.es/m/20241026184936.ae.nmisch@google.com
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index c0ebfb8ec0d..236f5e78fef 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -5974,8 +5974,8 @@ heap_abort_speculative(Relation relation, ItemPointer tid) * transaction. If compatible, return true with the buffer exclusive-locked, * and the caller must release that by calling * heap_inplace_update_and_unlock(), calling heap_inplace_unlock(), or raising - * an error. Otherwise, return false after blocking transactions, if any, - * have ended. + * an error. Otherwise, call release_callback(arg), wait for blocking + * transactions to end, and return false. * * Since this is intended for system catalogs and SERIALIZABLE doesn't cover * DDL, this doesn't guarantee any particular predicate locking. @@ -6009,7 +6009,8 @@ heap_abort_speculative(Relation relation, ItemPointer tid) */ bool heap_inplace_lock(Relation relation, - HeapTuple oldtup_ptr, Buffer buffer) + HeapTuple oldtup_ptr, Buffer buffer, + void (*release_callback) (void *), void *arg) { HeapTupleData oldtup = *oldtup_ptr; /* minimize diff vs. heap_update() */ TM_Result result; @@ -6074,6 +6075,7 @@ heap_inplace_lock(Relation relation, lockmode, NULL)) { LockBuffer(buffer, BUFFER_LOCK_UNLOCK); + release_callback(arg); ret = false; MultiXactIdWait((MultiXactId) xwait, mxact_status, infomask, relation, &oldtup.t_self, XLTW_Update, @@ -6089,6 +6091,7 @@ heap_inplace_lock(Relation relation, else { LockBuffer(buffer, BUFFER_LOCK_UNLOCK); + release_callback(arg); ret = false; XactLockTableWait(xwait, relation, &oldtup.t_self, XLTW_Update); @@ -6100,6 +6103,7 @@ heap_inplace_lock(Relation relation, if (!ret) { LockBuffer(buffer, BUFFER_LOCK_UNLOCK); + release_callback(arg); } } |