From 68693317d2896934628667f97c3dfec9b2c11ea3 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Sat, 15 Oct 2011 06:57:18 -0400
Subject: [PATCH] Simplify ProcArrayRemove().

---
 src/backend/access/transam/twophase.c |  2 +-
 src/backend/storage/ipc/procarray.c   | 25 +++----------------------
 src/backend/storage/lmgr/proc.c       |  2 +-
 src/include/storage/procarray.h       |  2 +-
 4 files changed, 6 insertions(+), 25 deletions(-)

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 058ea19262..4505918ef6 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1310,7 +1310,7 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
 									   hdr->nsubxacts, children,
 									   hdr->nabortrels, abortrels);
 
-	ProcArrayRemove(&gxact->proc, latestXid);
+	ProcArrayRemove(&gxact->proc);
 	SnapArrayRemoveRunningXids(xid, hdr->nsubxacts, children, latestXid);
 
 	/*
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 695e3bb33b..5145e5b054 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -236,15 +236,11 @@ ProcArrayAdd(PGPROC *proc)
 /*
  * Remove the specified PGPROC from the shared array.
  *
- * When latestXid is a valid XID, we are removing a live 2PC gxact from the
- * array, and thus causing it to appear as "not running" anymore.  In this
- * case we must advance latestCompletedXid.  (This is essentially the same
- * as ProcArrayEndTransaction followed by removal of the PGPROC, but we take
- * the ProcArrayLock only once, and don't damage the content of the PGPROC;
- * twophase.c depends on the latter.)
+ * (This is similar to ProcArrayEndTransaction, but we don't damage the content
+ * of the PGPROC; twophase.c depends on the this.)
  */
 void
-ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
+ProcArrayRemove(PGPROC *proc)
 {
 	ProcArrayStruct *arrayP = procArray;
 	int			index;
@@ -257,21 +253,6 @@ ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
 
 	LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
 
-	if (TransactionIdIsValid(latestXid))
-	{
-		Assert(TransactionIdIsValid(proc->xid));
-
-		/* Advance global latestCompletedXid while holding the lock */
-		if (TransactionIdPrecedes(ShmemVariableCache->latestCompletedXid,
-								  latestXid))
-			ShmemVariableCache->latestCompletedXid = latestXid;
-	}
-	else
-	{
-		/* Shouldn't be trying to remove a live transaction here */
-		Assert(!TransactionIdIsValid(proc->xid));
-	}
-
 	for (index = 0; index < arrayP->numProcs; index++)
 	{
 		if (arrayP->procs[index] == proc)
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 22cb0b8283..aa00bf5035 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -669,7 +669,7 @@ static void
 RemoveProcFromArray(int code, Datum arg)
 {
 	Assert(MyProc != NULL);
-	ProcArrayRemove(MyProc, InvalidTransactionId);
+	ProcArrayRemove(MyProc);
 }
 
 /*
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index ee87e83479..072bd2b5a7 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -21,7 +21,7 @@
 extern Size ProcArrayShmemSize(void);
 extern void CreateSharedProcArray(void);
 extern void ProcArrayAdd(PGPROC *proc);
-extern void ProcArrayRemove(PGPROC *proc, TransactionId latestXid);
+extern void ProcArrayRemove(PGPROC *proc);
 
 extern void ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid);
 extern void ProcArrayClearTransaction(PGPROC *proc);
-- 
2.39.5