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 ea781a8b29cfa979e142d3985e112cfd02ae5287..2c024f829933529357418e887d478316ccf112b9 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.