diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 108 |
1 files changed, 74 insertions, 34 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index ae15c0b9556..808b942c5e8 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -4090,7 +4090,7 @@ get_mxact_status_for_lock(LockTupleMode mode, bool is_update) * cid: current command ID (used for visibility test, and stored into * tuple's cmax if lock is successful) * mode: indicates if shared or exclusive tuple lock is desired - * nowait: if true, ereport rather than blocking if lock not available + * wait_policy: what to do if tuple lock is not available * follow_updates: if true, follow the update chain to also lock descendant * tuples. * @@ -4103,6 +4103,7 @@ get_mxact_status_for_lock(LockTupleMode mode, bool is_update) * HeapTupleMayBeUpdated: lock was successfully acquired * HeapTupleSelfUpdated: lock failed because tuple updated by self * HeapTupleUpdated: lock failed because tuple updated by other xact + * HeapTupleWouldBlock: lock couldn't be acquired and wait_policy is skip * * In the failure cases, the routine fills *hufd with the tuple's t_ctid, * t_xmax (resolving a possible MultiXact, if necessary), and t_cmax @@ -4114,7 +4115,7 @@ get_mxact_status_for_lock(LockTupleMode mode, bool is_update) */ HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tuple, - CommandId cid, LockTupleMode mode, bool nowait, + CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy, bool follow_updates, Buffer *buffer, HeapUpdateFailureData *hufd) { @@ -4220,16 +4221,28 @@ l3: */ if (!have_tuple_lock) { - if (nowait) + switch (wait_policy) { - if (!ConditionalLockTupleTuplock(relation, tid, mode)) - ereport(ERROR, - (errcode(ERRCODE_LOCK_NOT_AVAILABLE), - errmsg("could not obtain lock on row in relation \"%s\"", - RelationGetRelationName(relation)))); + case LockWaitBlock: + LockTupleTuplock(relation, tid, mode); + break; + case LockWaitSkip: + if (!ConditionalLockTupleTuplock(relation, tid, mode)) + { + result = HeapTupleWouldBlock; + /* recovery code expects to have buffer lock held */ + LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE); + goto failed; + } + break; + case LockWaitError: + if (!ConditionalLockTupleTuplock(relation, tid, mode)) + ereport(ERROR, + (errcode(ERRCODE_LOCK_NOT_AVAILABLE), + errmsg("could not obtain lock on row in relation \"%s\"", + RelationGetRelationName(relation)))); + break; } - else - LockTupleTuplock(relation, tid, mode); have_tuple_lock = true; } @@ -4432,21 +4445,35 @@ l3: if (status >= MultiXactStatusNoKeyUpdate) elog(ERROR, "invalid lock mode in heap_lock_tuple"); - /* wait for multixact to end */ - if (nowait) + /* wait for multixact to end, or die trying */ + switch (wait_policy) { - if (!ConditionalMultiXactIdWait((MultiXactId) xwait, - status, infomask, relation, - NULL)) - ereport(ERROR, - (errcode(ERRCODE_LOCK_NOT_AVAILABLE), - errmsg("could not obtain lock on row in relation \"%s\"", - RelationGetRelationName(relation)))); + case LockWaitBlock: + MultiXactIdWait((MultiXactId) xwait, status, infomask, + relation, &tuple->t_data->t_ctid, XLTW_Lock, NULL); + break; + case LockWaitSkip: + if (!ConditionalMultiXactIdWait((MultiXactId) xwait, + status, infomask, relation, + NULL)) + { + result = HeapTupleWouldBlock; + /* recovery code expects to have buffer lock held */ + LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE); + goto failed; + } + break; + case LockWaitError: + if (!ConditionalMultiXactIdWait((MultiXactId) xwait, + status, infomask, relation, + NULL)) + ereport(ERROR, + (errcode(ERRCODE_LOCK_NOT_AVAILABLE), + errmsg("could not obtain lock on row in relation \"%s\"", + RelationGetRelationName(relation)))); + + break; } - else - MultiXactIdWait((MultiXactId) xwait, status, infomask, - relation, &tuple->t_data->t_ctid, - XLTW_Lock, NULL); /* if there are updates, follow the update chain */ if (follow_updates && @@ -4491,18 +4518,30 @@ l3: } else { - /* wait for regular transaction to end */ - if (nowait) + /* wait for regular transaction to end, or die trying */ + switch (wait_policy) { - if (!ConditionalXactLockTableWait(xwait)) - ereport(ERROR, - (errcode(ERRCODE_LOCK_NOT_AVAILABLE), - errmsg("could not obtain lock on row in relation \"%s\"", - RelationGetRelationName(relation)))); + case LockWaitBlock: + XactLockTableWait(xwait, relation, &tuple->t_data->t_ctid, + XLTW_Lock); + break; + case LockWaitSkip: + if (!ConditionalXactLockTableWait(xwait)) + { + result = HeapTupleWouldBlock; + /* recovery code expects to have buffer lock held */ + LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE); + goto failed; + } + break; + case LockWaitError: + if (!ConditionalXactLockTableWait(xwait)) + ereport(ERROR, + (errcode(ERRCODE_LOCK_NOT_AVAILABLE), + errmsg("could not obtain lock on row in relation \"%s\"", + RelationGetRelationName(relation)))); + break; } - else - XactLockTableWait(xwait, relation, &tuple->t_data->t_ctid, - XLTW_Lock); /* if there are updates, follow the update chain */ if (follow_updates && @@ -4564,7 +4603,8 @@ l3: failed: if (result != HeapTupleMayBeUpdated) { - Assert(result == HeapTupleSelfUpdated || result == HeapTupleUpdated); + Assert(result == HeapTupleSelfUpdated || result == HeapTupleUpdated || + result == HeapTupleWouldBlock); Assert(!(tuple->t_data->t_infomask & HEAP_XMAX_INVALID)); hufd->ctid = tuple->t_data->t_ctid; hufd->xmax = HeapTupleHeaderGetUpdateXid(tuple->t_data); |