Remote dtm_get_snapshot

knizhnik · knizhnik · commit 6f3d57325efe · 2015-09-18T15:47:52.000+03:00
diff --git a/contrib/pg_xtm/pg_dtm.c b/contrib/pg_xtm/pg_dtm.c
@@ -192,6 +192,11 @@ static void DtmUpdateRecentXmin(void)
 static Snapshot DtmGetSnapshot(Snapshot snapshot)
 {
     XTM_TRACE("XTM: DtmGetSnapshot \n");
+    if (DtmGlobalTransaction && !DtmHasSnapshot) { 
+        DtmHasSnapshot = true;
+        DtmEnsureConnection();
+        DtmGlobalGetSnapshot(DtmConn, DtmNodeId, GetCurrentTransactionId(), &DtmSnapshot);
+    }
     snapshot = GetLocalSnapshotData(snapshot);        
     if (DtmHasSnapshot) {  
         DtmCopySnapshot(snapshot, &DtmSnapshot);
@@ -204,7 +209,7 @@ static Snapshot DtmGetSnapshot(Snapshot snapshot)
 static bool DtmTransactionIsInProgress(TransactionId xid)
 {
     XTM_TRACE("XTM: DtmTransactionIsInProgress \n");
-    return TransactionIdIsRunning(xid);
+    return TransactionIdIsRunning(xid);// || (DtmHasSnapshot && TransactionIdIsInDtmSnapshot(&DtmSnapshot, xid));
 }
 
 static XidStatus DtmGetTransactionStatus(TransactionId xid, XLogRecPtr *lsn)
diff --git a/contrib/pg_xtm/tests/transfers.go b/contrib/pg_xtm/tests/transfers.go
@@ -76,10 +76,6 @@ func prepare_db() {
     exec(conn1, "select dtm_begin_transaction($1, $2)", nodes, xids)
     exec(conn2, "select dtm_begin_transaction($1, $2)", nodes, xids)
     
-    // first global statement 
-    exec(conn1, "select dtm_get_snapshot()")
-    exec(conn2, "select dtm_get_snapshot()")
-    
     for i := 0; i < N_ACCOUNTS; i++ {
         exec(conn1, "insert into t values($1, $2)", i, INIT_AMOUNT)
         exec(conn2, "insert into t values($1, $2)", i, INIT_AMOUNT)
@@ -97,7 +93,7 @@ func max(a, b int64) int64 {
 
 func transfer(id int, wg *sync.WaitGroup) {
     var err error
-    var sum1, sum2, sum int32
+ //   var sum1, sum2, sum int32
     var xids []int32 = make([]int32, 2)
 
     conn1, err := pgx.Connect(cfg1)
@@ -125,31 +121,10 @@ func transfer(id int, wg *sync.WaitGroup) {
         // register global transaction in DTMD
         exec(conn1, "select dtm_begin_transaction($1, $2)", nodes, xids)
         exec(conn2, "select dtm_begin_transaction($1, $2)", nodes, xids)
-        
-        // first global statement 
-        exec(conn1, "select dtm_get_snapshot()")
-        exec(conn2, "select dtm_get_snapshot()")
-        
-        sum1 = execQuery(conn1, "select sum(v) from t")
-        sum2 = execQuery(conn2, "select sum(v) from t")
-        sum = sum1 + sum2
-        
-        exec(conn1, "select dtm_get_snapshot()")
-        exec(conn2, "select dtm_get_snapshot()")
 
         exec(conn1, "update t set v = v + $1 where u=$2", amount, account1)
         exec(conn2, "update t set v = v - $1 where u=$2", amount, account2)
-        
-        exec(conn1, "select dtm_get_snapshot()")
-        exec(conn2, "select dtm_get_snapshot()")
 
-        sum1 = execQuery(conn1, "select sum(v) from t")
-        sum2 = execQuery(conn2, "select sum(v) from t")
-                
-        if (sum1 + sum2 != sum) { 
-            fmt.Println("Before = ", sum, ", after=", sum1 + sum2, ", xids=", xids)        
-        }
-        
         commit(conn1, conn2)
     }
 
@@ -180,9 +155,6 @@ func inspect(wg *sync.WaitGroup) {
         exec(conn1, "select dtm_begin_transaction($1, $2)", nodes, xids)
         exec(conn2, "select dtm_begin_transaction($1, $2)", nodes, xids)
 
-        exec(conn1, "select dtm_get_snapshot()")
-        exec(conn2, "select dtm_get_snapshot()")
-
         sum1 = execQuery(conn1, "select sum(v) from t")
         sum2 = execQuery(conn2, "select sum(v) from t")
 

Original file line number	Diff line number	Diff line change
`@@ -192,6 +192,11 @@ static void DtmUpdateRecentXmin(void)`
`192`	`192`	`static Snapshot DtmGetSnapshot(Snapshot snapshot)`
`193`	`193`	`{`
`194`	`194`	`XTM_TRACE("XTM: DtmGetSnapshot \n");`
	`195`	`+ if (DtmGlobalTransaction && !DtmHasSnapshot) {`
	`196`	`+ DtmHasSnapshot = true;`
	`197`	`+ DtmEnsureConnection();`
	`198`	`+ DtmGlobalGetSnapshot(DtmConn, DtmNodeId, GetCurrentTransactionId(), &DtmSnapshot);`
	`199`	`+ }`
`195`	`200`	`snapshot = GetLocalSnapshotData(snapshot);`
`196`	`201`	`if (DtmHasSnapshot) {`
`197`	`202`	`DtmCopySnapshot(snapshot, &DtmSnapshot);`
`@@ -204,7 +209,7 @@ static Snapshot DtmGetSnapshot(Snapshot snapshot)`
`204`	`209`	`static bool DtmTransactionIsInProgress(TransactionId xid)`
`205`	`210`	`{`
`206`	`211`	`XTM_TRACE("XTM: DtmTransactionIsInProgress \n");`
`207`		`- return TransactionIdIsRunning(xid);`
	`212`	`+ return TransactionIdIsRunning(xid);// \|\| (DtmHasSnapshot && TransactionIdIsInDtmSnapshot(&DtmSnapshot, xid));`
`208`	`213`	`}`
`209`	`214`
`210`	`215`	`static XidStatus DtmGetTransactionStatus(TransactionId xid, XLogRecPtr *lsn)`