Use malloc() in GetLockConflicts() when called InHotStandby to avoid repeated

palloc calls. Current code assumed this was already true, so this is a bug fix.

diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index ea781a8..2c024f8 100644 (file)
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.191 2010/01/23 16:37:12 sriggs Exp $
+ *       $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.192 2010/01/28 10:05:37 sriggs Exp $
  *
  * NOTES
  *       A lock table is a shared memory hash table.  When
@@ -1790,7 +1790,7 @@ LockReassignCurrentOwner(void)
 VirtualTransactionId *
 GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
 {
-       VirtualTransactionId *vxids;
+       static VirtualTransactionId *vxids = NULL;
        LOCKMETHODID lockmethodid = locktag->locktag_lockmethodid;
        LockMethod      lockMethodTable;
        LOCK       *lock;
@@ -1812,8 +1812,22 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
         * need enough space for MaxBackends + a terminator, since prepared xacts
         * don't count.
         */
-       vxids = (VirtualTransactionId *)
-               palloc0(sizeof(VirtualTransactionId) * (MaxBackends + 1));
+       if (!InHotStandby)
+               vxids = (VirtualTransactionId *)
+                       palloc0(sizeof(VirtualTransactionId) * (MaxBackends + 1));
+       else
+       {
+               if (vxids == NULL)
+               {
+                       vxids = (VirtualTransactionId *)
+                               malloc(sizeof(VirtualTransactionId) * (MaxBackends + 1));
+                       if (vxids == NULL)
+                               ereport(ERROR,
+                                       (errcode(ERRCODE_OUT_OF_MEMORY),
+                                        errmsg("out of memory")));
+
+               }
+       }
 
        /*
         * Look up the lock object matching the tag.