3 files changed, 30 insertions, 22 deletions

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 5139af69bbf..3a0b190abcf 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -318,7 +318,7 @@ MarkAsPreparing(TransactionId xid, const char *gid,
 	proc->lxid = (LocalTransactionId) xid;
 	pgxact->xid = xid;
 	pgxact->xmin = InvalidTransactionId;
-	pgxact->inCommit = false;
+	pgxact->delayChkpt = false;
 	pgxact->vacuumFlags = 0;
 	proc->pid = 0;
 	proc->backendId = InvalidBackendId;
@@ -1034,18 +1034,18 @@ EndPrepare(GlobalTransaction gxact)
 	 * odds of a PANIC actually occurring should be very tiny given that we
 	 * were able to write the bogus CRC above.
 	 *
-	 * We have to set inCommit here, too; otherwise a checkpoint starting
+	 * We have to set delayChkpt here, too; otherwise a checkpoint starting
 	 * immediately after the WAL record is inserted could complete without
 	 * fsync'ing our state file.  (This is essentially the same kind of race
 	 * condition as the COMMIT-to-clog-write case that RecordTransactionCommit
-	 * uses inCommit for; see notes there.)
+	 * uses delayChkpt for; see notes there.)
 	 *
 	 * We save the PREPARE record's location in the gxact for later use by
 	 * CheckPointTwoPhase.
 	 */
 	START_CRIT_SECTION();
 
-	MyPgXact->inCommit = true;
+	MyPgXact->delayChkpt = true;
 
 	gxact->prepare_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE,
 									records.head);
@@ -1086,7 +1086,7 @@ EndPrepare(GlobalTransaction gxact)
 	 * checkpoint starting after this will certainly see the gxact as a
 	 * candidate for fsyncing.
 	 */
-	MyPgXact->inCommit = false;
+	MyPgXact->delayChkpt = false;
 
 	END_CRIT_SECTION();
 
@@ -1972,7 +1972,7 @@ RecoverPreparedTransactions(void)
  *	RecordTransactionCommitPrepared
  *
  * This is basically the same as RecordTransactionCommit: in particular,
- * we must set the inCommit flag to avoid a race condition.
+ * we must set the delayChkpt flag to avoid a race condition.
  *
  * We know the transaction made at least one XLOG entry (its PREPARE),
  * so it is never possible to optimize out the commit record.
@@ -1995,7 +1995,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
 	START_CRIT_SECTION();
 
 	/* See notes in RecordTransactionCommit */
-	MyPgXact->inCommit = true;
+	MyPgXact->delayChkpt = true;
 
 	/* Emit the XLOG commit record */
 	xlrec.xid = xid;
@@ -2053,7 +2053,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
 	TransactionIdCommitTree(xid, nchildren, children);
 
 	/* Checkpoint can proceed now */
-	MyPgXact->inCommit = false;
+	MyPgXact->delayChkpt = false;
 
 	END_CRIT_SECTION();
 
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 349bdbcd929..a36c8061a2b 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1001,13 +1001,13 @@ RecordTransactionCommit(void)
 		 * RecordTransactionAbort.	That's because loss of a transaction abort
 		 * is noncritical; the presumption would be that it aborted, anyway.
 		 *
-		 * It's safe to change the inCommit flag of our own backend without
+		 * It's safe to change the delayChkpt flag of our own backend without
 		 * holding the ProcArrayLock, since we're the only one modifying it.
-		 * This makes checkpoint's determination of which xacts are inCommit a
+		 * This makes checkpoint's determination of which xacts are delayChkpt a
 		 * bit fuzzy, but it doesn't matter.
 		 */
 		START_CRIT_SECTION();
-		MyPgXact->inCommit = true;
+		MyPgXact->delayChkpt = true;
 
 		SetCurrentTransactionStopTimestamp();
 
@@ -1160,7 +1160,7 @@ RecordTransactionCommit(void)
 	 */
 	if (markXidCommitted)
 	{
-		MyPgXact->inCommit = false;
+		MyPgXact->delayChkpt = false;
 		END_CRIT_SECTION();
 	}
 
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 411807006ac..2b579f9b727 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -6884,8 +6884,8 @@ CreateCheckPoint(int flags)
 	XLogRecData rdata;
 	uint32		freespace;
 	XLogSegNo	_logSegNo;
-	TransactionId *inCommitXids;
-	int			nInCommit;
+	VirtualTransactionId *vxids;
+	int	nvxids;
 
 	/*
 	 * An end-of-recovery checkpoint is really a shutdown checkpoint, just
@@ -7056,9 +7056,14 @@ CreateCheckPoint(int flags)
 	TRACE_POSTGRESQL_CHECKPOINT_START(flags);
 
 	/*
-	 * Before flushing data, we must wait for any transactions that are
-	 * currently in their commit critical sections.  If an xact inserted its
-	 * commit record into XLOG just before the REDO point, then a crash
+	 * In some cases there are groups of actions that must all occur on
+	 * one side or the other of a checkpoint record. Before flushing the
+	 * checkpoint record we must explicitly wait for any backend currently
+	 * performing those groups of actions.
+	 *
+	 * One example is end of transaction, so we must wait for any transactions
+	 * that are currently in commit critical sections.  If an xact inserted
+	 * its commit record into XLOG just before the REDO point, then a crash
 	 * restart from the REDO point would not replay that record, which means
 	 * that our flushing had better include the xact's update of pg_clog.  So
 	 * we wait till he's out of his commit critical section before proceeding.
@@ -7073,21 +7078,24 @@ CreateCheckPoint(int flags)
 	 * protected by different locks, but again that seems best on grounds of
 	 * minimizing lock contention.)
 	 *
-	 * A transaction that has not yet set inCommit when we look cannot be at
+	 * A transaction that has not yet set delayChkpt when we look cannot be at
 	 * risk, since he's not inserted his commit record yet; and one that's
 	 * already cleared it is not at risk either, since he's done fixing clog
 	 * and we will correctly flush the update below.  So we cannot miss any
 	 * xacts we need to wait for.
 	 */
-	nInCommit = GetTransactionsInCommit(&inCommitXids);
-	if (nInCommit > 0)
+	vxids = GetVirtualXIDsDelayingChkpt(&nvxids);
+	if (nvxids > 0)
 	{
+		uint	nwaits = 0;
+
 		do
 		{
 			pg_usleep(10000L);	/* wait for 10 msec */
-		} while (HaveTransactionsInCommit(inCommitXids, nInCommit));
+			nwaits++;
+		} while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids));
 	}
-	pfree(inCommitXids);
+	pfree(vxids);
 
 	/*
 	 * Get the other info we need for the checkpoint record.