Install infrastructure for shared-memory free space map. Doesn't actually

do anything yet, but it has the necessary connections to initialization
and so forth.  Make some gestures towards allowing number of blocks in
a relation to be BlockNumber, ie, unsigned int, rather than signed int.
(I doubt I got all the places that are sloppy about it, yet.)  On the
way, replace the hardwired NLOCKS_PER_XACT fudge factor with a GUC
variable.

src/backend/storage/lmgr/lock.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.89 2001/06/22 00:04:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.90 2001/06/27 23:31:39 tgl Exp $
  *
  * NOTES
  *	  Outside modules can create a lock table and acquire/release
@@ -40,6 +40,13 @@
 #include "utils/memutils.h"
 #include "utils/ps_status.h"
 
+
+/* This configuration variable is used to set the lock table size */
+int		max_locks_per_xact;		/* set by guc.c */
+
+#define NLOCKENTS(maxBackends)	(max_locks_per_xact * (maxBackends))
+
+
 static int WaitOnLock(LOCKMETHOD lockmethod, LOCKMODE lockmode,
 		   LOCK *lock, HOLDER *holder);
 static void LockCountMyLocks(SHMEM_OFFSET lockOffset, PROC *proc,
@@ -1388,6 +1395,7 @@ int
 LockShmemSize(int maxBackends)
 {
 	int			size = 0;
+	long		max_table_size = NLOCKENTS(maxBackends);
 
 	size += MAXALIGN(sizeof(PROC_HDR)); /* ProcGlobal */
 	size += maxBackends * MAXALIGN(sizeof(PROC));		/* each MyProc */
@@ -1395,12 +1403,12 @@ LockShmemSize(int maxBackends)
 																 * lockMethodTable->ctl */
 
 	/* lockHash table */
-	size += hash_estimate_size(NLOCKENTS(maxBackends),
+	size += hash_estimate_size(max_table_size,
 							   SHMEM_LOCKTAB_KEYSIZE,
 							   SHMEM_LOCKTAB_DATASIZE);
 
 	/* holderHash table */
-	size += hash_estimate_size(NLOCKENTS(maxBackends),
+	size += hash_estimate_size(max_table_size,
 							   SHMEM_HOLDERTAB_KEYSIZE,
 							   SHMEM_HOLDERTAB_DATASIZE);