Widen the nLocks counts in local lock tables from int to int64. This

forestalls potential overflow when the same table (or other object, but
usually tables) is accessed by very many successive queries within a single
transaction.  Per report from Michael Milligan.

Back-patch to 8.0, which is as far back as the patch conveniently applies.
There have been no reports of overflow in pre-8.3 releases, but clearly the
risk existed all along.  (Michael's report suggests that 8.3 may consume lock
counts faster than prior releases, but with no test case to look at it's hard
to be sure about that.  Widening the counts seems a good future-proofing
measure in any event.)

diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index e335d753303ba3ef3148555d5ed0ae02f3f780fb..75ab378a37a6ddad09f8016ea2da07e9445439bf 100644 (file)
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -393,7 +393,7 @@ typedef struct LOCALLOCKOWNER
         * Must use a forward struct reference to avoid circularity.
         */
        struct ResourceOwnerData *owner;
-       int                     nLocks;                 /* # of times held by this owner */
+       int64           nLocks;                 /* # of times held by this owner */
 } LOCALLOCKOWNER;
 
 typedef struct LOCALLOCK
@@ -405,7 +405,7 @@ typedef struct LOCALLOCK
        LOCK       *lock;                       /* associated LOCK object in shared mem */
        PROCLOCK   *proclock;           /* associated PROCLOCK object in shmem */
        uint32          hashcode;               /* copy of LOCKTAG's hash value */
-       int                     nLocks;                 /* total number of times lock is held */
+       int64           nLocks;                 /* total number of times lock is held */
        int                     numLockOwners;  /* # of relevant ResourceOwners */
        int                     maxLockOwners;  /* allocated size of array */
        LOCALLOCKOWNER *lockOwners; /* dynamically resizable array */