From 9680a712051bcf043beab5a49472e7da2f5a369a Mon Sep 17 00:00:00 2001
From: "Vadim B. Mikheev" <vadim4o@yahoo.com>
Date: Thu, 3 Jun 1999 04:41:41 +0000
Subject: [PATCH] 1. MyProc->xid assignment is moved to GetNewTransactionId so
 newer    transactions will not assume that MyProc transaction was committed  
  before snapshot calculations. With old MyProc->xid assignment    (in
 xact.c:StartTransaction()) there was ability to see the same    row twice (I
 used gdb for this)!... 2. Assignments of InvalidTransactionId to MyProc->xid
 and MyProc->xmin    are moved from xact.c:CommitTransaction() to   
 xact.c:RecordTransactionCommit() - this invalidation must be done    before
 releasing transaction locks or bad (too high) XmaxRecent value    might be
 used by vacuum ("ERROR:  Child itemid marked as unused"    reported by
 "Hiroshi Inoue" <Inoue@tpf.co.jp>; once again, gdb    allowed me reproduce
 this error).

---
 src/backend/access/transam/varsup.c |  6 +++++-
 src/backend/access/transam/xact.c   | 30 +++++++++++++----------------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 4bcc55bb92c..fd23de1d984 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.20 1999/05/25 16:07:48 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.21 1999/06/03 04:41:40 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,6 +19,7 @@
 #include <access/xact.h>
 #include <access/heapam.h>
 #include <catalog/catname.h>
+#include <storage/proc.h>
 
 static void GetNewObjectIdBlock(Oid *oid_return, int oid_block_size);
 static void VariableRelationGetNextOid(Oid *oid_return);
@@ -308,6 +309,9 @@ GetNewTransactionId(TransactionId *xid)
 	TransactionIdAdd(&(ShmemVariableCache->nextXid), 1);
 	(ShmemVariableCache->xid_count)--;
 
+	if (MyProc != (PROC *) NULL)
+		MyProc->xid = *xid;
+
 	SpinRelease(OidGenLockId);
 }
 
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 8453d8688c2..6884e635904 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.37 1999/05/31 22:53:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.38 1999/06/03 04:41:41 vadim Exp $
  *
  * NOTES
  *		Transaction aborts can now occur two ways:
@@ -646,6 +646,18 @@ RecordTransactionCommit()
 	FlushBufferPool(!TransactionFlushEnabled());
 	if (leak)
 		ResetBufferPool();
+
+	/*
+	 * Let others know about no transaction in progress.
+	 * Note that this must be done _before_ releasing locks
+	 * we hold or bad (too high) XmaxRecent value might be
+	 * used by vacuum.
+	 */
+	if (MyProc != (PROC *) NULL)
+	{
+		MyProc->xid = InvalidTransactionId;
+		MyProc->xmin = InvalidTransactionId;
+	}
 }
 
 
@@ -884,13 +896,6 @@ StartTransaction()
 	 */
 	s->state = TRANS_INPROGRESS;
 
-	/*
-	 * Let others to know about current transaction is in progress - vadim
-	 * 11/26/96
-	 */
-	if (MyProc != (PROC *) NULL)
-		MyProc->xid = s->transactionIdData;
-
 }
 
 /* ---------------
@@ -958,15 +963,6 @@ CommitTransaction()
 	 */
 	s->state = TRANS_DEFAULT;
 
-	/*
-	 * Let others to know about no transaction in progress - vadim
-	 * 11/26/96
-	 */
-	if (MyProc != (PROC *) NULL)
-	{
-		MyProc->xid = InvalidTransactionId;
-		MyProc->xmin = InvalidTransactionId;
-	}
 }
 
 /* --------------------------------