Support work with large snapshots

knizhnik · knizhnik · commit dbad0e800cf3 · 2015-10-09T19:46:37.000+03:00
diff --git a/contrib/pg_dtm/libdtm.c b/contrib/pg_dtm/libdtm.c
@@ -301,7 +301,7 @@ void DtmInitSnapshot(Snapshot snapshot)
 		 * we are in recovery, see later comments.
 		 */
 		snapshot->xip = (TransactionId *)
-			malloc(GetMaxSnapshotXidCount() * sizeof(TransactionId));
+			malloc(GetMaxSnapshotSubxidCount() * sizeof(TransactionId));
 		if (snapshot->xip == NULL)
 			ereport(ERROR,
 					(errcode(ERRCODE_OUT_OF_MEMORY),
diff --git a/contrib/pg_dtm/pg_dtm.c b/contrib/pg_dtm/pg_dtm.c
@@ -205,22 +205,39 @@ static void DtmMergeWithGlobalSnapshot(Snapshot dst)
 	if (src->xmin < dst->xmin) {
 		dst->xmin = src->xmin;
 	}
-
-	n = dst->xcnt;
-	Assert(src->xcnt + n <= GetMaxSnapshotXidCount());
-	memcpy(dst->xip + n, src->xip, src->xcnt*sizeof(TransactionId));
-	n += src->xcnt;
-
-	qsort(dst->xip, n, sizeof(TransactionId), xidComparator);
-	xid = InvalidTransactionId;
-
-	for (i = 0, j = 0; i < n && dst->xip[i] < dst->xmax; i++) {
-		if (dst->xip[i] != xid) {
-			dst->xip[j++] = xid = dst->xip[i];
-		}
-	}
-	dst->xcnt = j;
-
+    Assert(src->subxcnt == 0);
+
+	if (src->xcnt + dst->subxcnt + dst->xcnt <= GetMaxSnapshotXidCount()) {
+        Assert(dst->subxcnt == 0);
+        memcpy(dst->xip + dst->xcnt, src->xip, src->xcnt*sizeof(TransactionId));
+        n = dst->xcnt + src->xcnt;
+
+        qsort(dst->xip, n, sizeof(TransactionId), xidComparator);
+        xid = InvalidTransactionId;
+        
+        for (i = 0, j = 0; i < n && dst->xip[i] < dst->xmax; i++) {
+            if (dst->xip[i] != xid) {
+                dst->xip[j++] = xid = dst->xip[i];
+            }
+        }
+        dst->xcnt = j;
+    } else { 
+        Assert(src->xcnt + dst->subxcnt + dst->xcnt <= GetMaxSnapshotSubxidCount());
+        memcpy(dst->subxip + dst->subxcnt, dst->xip, dst->xcnt*sizeof(TransactionId));
+        memcpy(dst->subxip + dst->subxcnt + dst->xcnt, src->xip, src->xcnt*sizeof(TransactionId));
+        n = dst->xcnt + dst->subxcnt + src->xcnt;
+        
+        qsort(dst->subxip, n, sizeof(TransactionId), xidComparator);
+        xid = InvalidTransactionId;
+        
+        for (i = 0, j = 0; i < n && dst->subxip[i] < dst->xmax; i++) {
+            if (dst->subxip[i] != xid) {
+                dst->subxip[j++] = xid = dst->subxip[i];
+            }
+        }
+        dst->subxcnt = j;
+        dst->xcnt = 0;
+    }
 	DumpSnapshot(dst, "merged");
 }
 
diff --git a/contrib/pg_dtm/sockhub/start-clients.sh b/contrib/pg_dtm/sockhub/start-clients.sh
@@ -1,4 +1,4 @@
-n_clients=100
+n_clients=200
 n_iters=100000
 ./sockhub -h $1 -p 5001 -f /tmp/p5002 &
 for ((i=0;i<n_clients;i++))
diff --git a/contrib/pg_dtm/tests/transfers.go b/contrib/pg_dtm/tests/transfers.go
@@ -207,7 +207,8 @@ func prepare_one(connstr string, wg *sync.WaitGroup) {
     }
     exec(conn, "drop table if exists t")
     exec(conn, "create table t(u int primary key, v int)")
-
+    exec(conn, "insert into t (select generate_series(0,1000000), $1)", cfg.Accounts.Balance)
+/*
     exec(conn, "begin transaction isolation level " + cfg.Isolation)
 
     start := time.Now()
@@ -223,7 +224,7 @@ func prepare_one(connstr string, wg *sync.WaitGroup) {
             start = time.Now()
         }
     }
-
+*/
     exec(conn, "commit")
     wg.Done()
 }
diff --git a/contrib/pg_dtm/tests/transfers.sh b/contrib/pg_dtm/tests/transfers.sh
@@ -3,4 +3,5 @@ go run transfers.go \
 	-d 'dbname=postgres port=5432' \
 	-d 'dbname=postgres port=5433' \
     -m \
+    -w 128 \
 	-g

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-n_clients=100`
	`1`	`+n_clients=200`
`2`	`2`	`n_iters=100000`
`3`	`3`	`./sockhub -h $1 -p 5001 -f /tmp/p5002 &`
`4`	`4`	`for ((i=0;i<n_clients;i++))`
Original file line number	Diff line number	Diff line change
`@@ -207,7 +207,8 @@ func prepare_one(connstr string, wg *sync.WaitGroup) {`
`207`	`207`	`}`
`208`	`208`	`exec(conn, "drop table if exists t")`
`209`	`209`	`exec(conn, "create table t(u int primary key, v int)")`
`210`		`-`
	`210`	`+ exec(conn, "insert into t (select generate_series(0,1000000), $1)", cfg.Accounts.Balance)`
	`211`	`+/*`
`211`	`212`	`exec(conn, "begin transaction isolation level " + cfg.Isolation)`
`212`	`213`
`213`	`214`	`start := time.Now()`
`@@ -223,7 +224,7 @@ func prepare_one(connstr string, wg *sync.WaitGroup) {`
`223`	`224`	`start = time.Now()`
`224`	`225`	`}`
`225`	`226`	`}`
`226`		`-`
	`227`	`+*/`
`227`	`228`	`exec(conn, "commit")`
`228`	`229`	`wg.Done()`
`229`	`230`	`}`