From f4a3e679306ebfbd150d8af3cdd481bea1619c52 Mon Sep 17 00:00:00 2001
From: Simon Riggs <simon@2ndQuadrant.com>
Date: Thu, 29 Nov 2012 23:46:54 +0000
Subject: [PATCH] Correctly init/deinit recovery xact environment. Previously
 we performed VirtualXactLockTableInsert but didn't set MyProc->lxid for
 Startup process. pg_locks now correctly shows "1/1" for vxid of Startup
 process during Hot Standby. At end of Hot Standby the Virtual Transaction was
 not deleted, leading to problems after promoting to normal running for some
 commands, such as CREATE INDEX CONCURRENTLY.

---
 src/backend/storage/ipc/standby.c |  9 ++++++++-
 src/backend/storage/lmgr/lmgr.c   | 18 ++++++++++++++++++
 src/include/storage/lmgr.h        |  1 +
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c
index df9a9a495b6..9d0c27219b9 100644
--- a/src/backend/storage/ipc/standby.c
+++ b/src/backend/storage/ipc/standby.c
@@ -82,7 +82,7 @@ InitRecoveryTransactionEnvironment(void)
 	 * hold AccessShareLocks so never block while we write or lock new rows.
 	 */
 	vxid.backendId = MyBackendId;
-	vxid.localTransactionId = GetNextLocalTransactionId();
+	vxid.localTransactionId = MyProc->lxid = GetNextLocalTransactionId();
 	VirtualXactLockTableInsert(vxid);
 
 	standbyState = STANDBY_INITIALIZED;
@@ -98,11 +98,18 @@ InitRecoveryTransactionEnvironment(void)
 void
 ShutdownRecoveryTransactionEnvironment(void)
 {
+	VirtualTransactionId vxid;
+
 	/* Mark all tracked in-progress transactions as finished. */
 	ExpireAllKnownAssignedTransactionIds();
 
 	/* Release all locks the tracked transactions were holding */
 	StandbyReleaseAllLocks();
+
+	/* Cleanup our VirtualTransaction */
+	vxid.backendId = MyBackendId;
+	vxid.localTransactionId = MyProc->lxid;
+	VirtualXactLockTableDelete(vxid);
 }
 
 
diff --git a/src/backend/storage/lmgr/lmgr.c b/src/backend/storage/lmgr/lmgr.c
index 75f2f2666e0..9a41d47fbbf 100644
--- a/src/backend/storage/lmgr/lmgr.c
+++ b/src/backend/storage/lmgr/lmgr.c
@@ -534,6 +534,24 @@ VirtualXactLockTableInsert(VirtualTransactionId vxid)
 	(void) LockAcquire(&tag, ExclusiveLock, false, false);
 }
 
+/*
+ *		VirtualXactLockTableDelete
+ *
+ * Release a Virtual Transaction lock. Only called by Startup process
+ * at end of Hot Standby.
+ */
+void
+VirtualXactLockTableDelete(VirtualTransactionId vxid)
+{
+	LOCKTAG		tag;
+
+	Assert(VirtualTransactionIdIsValid(vxid));
+
+	SET_LOCKTAG_VIRTUALTRANSACTION(tag, vxid);
+
+	(void) LockRelease(&tag, ExclusiveLock, false);
+}
+
 /*
  *		VirtualXactLockTableWait
  *
diff --git a/src/include/storage/lmgr.h b/src/include/storage/lmgr.h
index 64b19e334c7..e40dcb6fe7e 100644
--- a/src/include/storage/lmgr.h
+++ b/src/include/storage/lmgr.h
@@ -58,6 +58,7 @@ extern bool ConditionalXactLockTableWait(TransactionId xid);
 
 /* Lock a VXID (used to wait for a transaction to finish) */
 extern void VirtualXactLockTableInsert(VirtualTransactionId vxid);
+extern void VirtualXactLockTableDelete(VirtualTransactionId vxid);
 extern void VirtualXactLockTableWait(VirtualTransactionId vxid);
 extern bool ConditionalVirtualXactLockTableWait(VirtualTransactionId vxid);
 
-- 
2.39.5