Revert "Detect too late snapshot"

kvap · kvap · commit 6beea7cbd105 · 2016-01-25T22:04:07.000+03:00
This reverts commit af5213a.
diff --git a/contrib/multimaster/multimaster.c b/contrib/multimaster/multimaster.c
@@ -748,7 +748,6 @@ static void DtmInitialize()
         dtm->initialized = false;
         BgwPoolInit(&dtm->pool, MMExecutor, MMDatabaseName, MMQueueSize);
 		RegisterXactCallback(DtmXactCallback, NULL);
-		RegisterSubXactCallback(DtmSubXactCallback, NULL);
 	}
 	LWLockRelease(AddinShmemInitLock);
 
diff --git a/contrib/pg_dtm/pg_dtm.c b/contrib/pg_dtm/pg_dtm.c
@@ -107,6 +107,7 @@ static SnapshotData DtmSnapshot = { HeapTupleSatisfiesMVCC };
 static bool DtmHasGlobalSnapshot;
 static bool DtmGlobalXidAssigned;
 static int DtmLocalXidReserve;
+static int DtmCurcid;
 static Snapshot DtmLastSnapshot;
 static TransactionManager DtmTM = {
 	DtmGetTransactionStatus,
@@ -613,9 +614,9 @@ static Snapshot DtmGetSnapshot(Snapshot snapshot)
 	}
 	if (TransactionIdIsValid(DtmNextXid) && snapshot != &CatalogSnapshotData)
 	{
-		if (!DtmHasGlobalSnapshot) { 
+		if (!DtmHasGlobalSnapshot && (snapshot != DtmLastSnapshot || DtmCurcid != snapshot->curcid))
 			DtmGlobalGetSnapshot(DtmNextXid, &DtmSnapshot, &dtm->minXid);
-		}
+		DtmCurcid = snapshot->curcid;
 		DtmLastSnapshot = snapshot;
 		DtmMergeWithGlobalSnapshot(snapshot);
 		if (!IsolationUsesXactSnapshot())
@@ -725,7 +726,6 @@ static void DtmInitialize()
 		dtm->nReservedXids = 0;
 		dtm->minXid = InvalidTransactionId;
 		RegisterXactCallback(DtmXactCallback, NULL);
-		RegisterSubXactCallback(DtmSubXactCallback, NULL);
 	}
 	LWLockRelease(AddinShmemInitLock);
 
diff --git a/contrib/pg_tsdtm/pg_dtm.c b/contrib/pg_tsdtm/pg_dtm.c
@@ -177,7 +177,7 @@ static cid_t dtm_sync(cid_t global_cid)
         SpinLockAcquire(&local->lock);
     }
 #endif
-    return local_cid;
+    return global_cid;
 }
 
 void
@@ -647,10 +647,7 @@ cid_t DtmLocalAccess(DtmCurrentTrans* x, GlobalTransactionId gtid, cid_t global_
         x->is_global = true;
     }
     SpinLockRelease(&local->lock);
-	if (global_cid < local_cid - DtmVacuumDelay*USEC) { 
-		elog(ERROR, "Too old snapshot: requested %ld, current %ld", global_cid, local_cid);
-	}
-    return global_cid;
+    return local_cid;
 }
 
 void DtmLocalBeginPrepare(GlobalTransactionId gtid)

Original file line number	Diff line number	Diff line change
`@@ -748,7 +748,6 @@ static void DtmInitialize()`
`748`	`748`	`dtm->initialized = false;`
`749`	`749`	`BgwPoolInit(&dtm->pool, MMExecutor, MMDatabaseName, MMQueueSize);`
`750`	`750`	`RegisterXactCallback(DtmXactCallback, NULL);`
`751`		`- RegisterSubXactCallback(DtmSubXactCallback, NULL);`
`752`	`751`	`}`
`753`	`752`	`LWLockRelease(AddinShmemInitLock);`
`754`	`753`
Original file line number	Diff line number	Diff line change
`@@ -177,7 +177,7 @@ static cid_t dtm_sync(cid_t global_cid)`
`177`	`177`	`SpinLockAcquire(&local->lock);`
`178`	`178`	`}`
`179`	`179`	`#endif`
`180`		`- return local_cid;`
	`180`	`+ return global_cid;`
`181`	`181`	`}`
`182`	`182`
`183`	`183`	`void`
`@@ -647,10 +647,7 @@ cid_t DtmLocalAccess(DtmCurrentTrans* x, GlobalTransactionId gtid, cid_t global_`
`647`	`647`	`x->is_global = true;`
`648`	`648`	`}`
`649`	`649`	`SpinLockRelease(&local->lock);`
`650`		`- if (global_cid < local_cid - DtmVacuumDelay*USEC) {`
`651`		`- elog(ERROR, "Too old snapshot: requested %ld, current %ld", global_cid, local_cid);`
`652`		`- }`
`653`		`- return global_cid;`
	`650`	`+ return local_cid;`
`654`	`651`	`}`
`655`	`652`
`656`	`653`	`void DtmLocalBeginPrepare(GlobalTransactionId gtid)`