diff options
Diffstat (limited to 'src/backend/access/transam/twophase.c')
| -rw-r--r-- | src/backend/access/transam/twophase.c | 63 |
1 files changed, 60 insertions, 3 deletions
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 2156de187c3..f6e7fa71d88 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -459,14 +459,24 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, proc->pgprocno = gxact->pgprocno; SHMQueueElemInit(&(proc->links)); proc->waitStatus = PROC_WAIT_STATUS_OK; - /* We set up the gxact's VXID as InvalidBackendId/XID */ - proc->lxid = (LocalTransactionId) xid; + if (LocalTransactionIdIsValid(MyProc->lxid)) + { + /* clone VXID, for TwoPhaseGetXidByVirtualXID() to find */ + proc->lxid = MyProc->lxid; + proc->backendId = MyBackendId; + } + else + { + Assert(AmStartupProcess() || !IsPostmasterEnvironment); + /* GetLockConflicts() uses this to specify a wait on the XID */ + proc->lxid = xid; + proc->backendId = InvalidBackendId; + } proc->xid = xid; Assert(proc->xmin == InvalidTransactionId); proc->delayChkpt = false; proc->statusFlags = 0; proc->pid = 0; - proc->backendId = InvalidBackendId; proc->databaseId = databaseid; proc->roleId = owner; proc->tempNamespaceId = InvalidOid; @@ -847,6 +857,53 @@ TwoPhaseGetGXact(TransactionId xid, bool lock_held) } /* + * TwoPhaseGetXidByVirtualXID + * Lookup VXID among xacts prepared since last startup. + * + * (This won't find recovered xacts.) If more than one matches, return any + * and set "have_more" to true. To witness multiple matches, a single + * BackendId must consume 2^32 LXIDs, with no intervening database restart. + */ +TransactionId +TwoPhaseGetXidByVirtualXID(VirtualTransactionId vxid, + bool *have_more) +{ + int i; + TransactionId result = InvalidTransactionId; + + Assert(VirtualTransactionIdIsValid(vxid)); + LWLockAcquire(TwoPhaseStateLock, LW_SHARED); + + for (i = 0; i < TwoPhaseState->numPrepXacts; i++) + { + GlobalTransaction gxact = TwoPhaseState->prepXacts[i]; + PGPROC *proc; + VirtualTransactionId proc_vxid; + + if (!gxact->valid) + continue; + proc = &ProcGlobal->allProcs[gxact->pgprocno]; + GET_VXID_FROM_PGPROC(proc_vxid, *proc); + if (VirtualTransactionIdEquals(vxid, proc_vxid)) + { + /* Startup process sets proc->backendId to InvalidBackendId. */ + Assert(!gxact->inredo); + + if (result != InvalidTransactionId) + { + *have_more = true; + break; + } + result = gxact->xid; + } + } + + LWLockRelease(TwoPhaseStateLock); + + return result; +} + +/* * TwoPhaseGetDummyBackendId * Get the dummy backend ID for prepared transaction specified by XID * |