From: Simon Riggs <simon@2ndQuadrant.com>
Date: Mon, 5 Oct 2009 10:04:52 +0000 (+0100)
Subject: Apply changes from Heikki's patch 001-Remove-some-dead-code... etc
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=9570e3e611c4ed72dde786e13391b022a422d01c;p=users%2Fsimon%2Fpostgres.git

Apply changes from Heikki's patch 001-Remove-some-dead-code... etc
Minor comment editing by me
---

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index daee07b71f..9d3f29e90f 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -377,7 +377,6 @@ ProcArrayClearTransaction(PGPROC *proc)
 	proc->lxid = InvalidLocalTransactionId;
 	proc->xmin = InvalidTransactionId;
 	proc->recoveryConflictMode = 0;
-	proc->recoveryConflictLSN = InvalidXLogRecPtr;
 
 	/* redundant, but just in case */
 	proc->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
@@ -1336,14 +1335,9 @@ GetRunningTransactionData(void)
 		numHeldLocks += proc->numHeldLocks;
 
 		/*
-		 * Save subtransaction XIDs.
-		 *
-		 * The other backend can add more subxids concurrently, but cannot
-		 * remove any.	Hence it's important to fetch nxids just once. Should
-		 * be safe to use memcpy, though.  (We needn't worry about missing any
-		 * xids added concurrently, because they must postdate xmax.)
-		 *
-		 * Again, our own XIDs *are* included in the snapshot.
+		 * Save subtransaction XIDs. Other backends can't remove entries while
+		 * we are holding ProcArrayLock, nor add new entries because we hold
+		 * hold XidGenLock.
 		 */
 		nxids = proc->subxids.nxids;
 
diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index b1d546ce8d..6569b5fcad 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -1580,13 +1580,7 @@ ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
 				 * Note that this is an atomic change and requires no locking.
 				 */
 				if (proc->recoveryConflictMode < cancel_mode)
-				{
-					if (cancel_mode == ERROR &&
-						XLByteLT(proc->recoveryConflictLSN, conflict_lsn))
-						proc->recoveryConflictLSN = conflict_lsn;
-
 					proc->recoveryConflictMode = cancel_mode;
-				}
 
 				/*
 				 * Do we expect it to talk? No, Mr. Bond, we expect it to die.
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 57294829e6..c1220011c1 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -99,12 +99,9 @@ struct PGPROC
 	int			numHeldLocks;	/* Number of AccessExclusiveLocks held by 
 								 * current backend. */
 	/*
-	 * InHotStandby mode, the lsn of the first conflict, if any.
-	 * Any block seen with changes made after this lsn will trigger
-	 * query cancelation. Always set recoveryConflictCancelMode after
-	 * setting conflictLSN so we can check this without spin locking.
+	 * While in Hot Standby mode, setting recoveryConflictMode instructs the
+	 * backend to commit suicide.
 	 */
-	XLogRecPtr 	recoveryConflictLSN;
 	int			recoveryConflictMode;
 
 	/* Info about LWLock the process is currently waiting for, if any. */