[ Newest version of patch applied.]

This patch is an updated version of the lock listing patch. I've made
the following changes:

    - write documentation
    - wrap the SRF in a view called 'pg_locks': all user-level
      access should be done through this view
    - re-diff against latest CVS

One thing I chose not to do is adapt the SRF to use the anonymous
composite type code from Joe Conway. I'll probably do that eventually,
but I'm not really convinced it's a significantly cleaner way to
bootstrap SRF builtins than the method this patch uses (of course, it
has other uses...)

Neil Conway

src/include/storage/lock.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lock.h,v 1.64 2002/08/01 05:18:34 momjian Exp $
+ * $Id: lock.h,v 1.65 2002/08/17 13:04:18 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -203,6 +203,21 @@ typedef struct PROCLOCK
 #define PROCLOCK_LOCKMETHOD(holder) \
 		(((LOCK *) MAKE_PTR((holder).tag.lock))->tag.lockmethod)
 
+/*
+ * This struct is used to encapsulate information passed from lmgr
+ * internals to the lock listing statistical functions (lockfuncs.c).
+ * It's just a convenient bundle of other lock.h structures. All
+ * the information at a given index (holders[i], procs[i], locks[i])
+ * is related.
+ */
+typedef struct
+{
+	int		  nelements;	/* The length of holders, procs, & locks */
+	int		  currIdx;		/* Current element being examined */
+	PGPROC	 *procs;
+	LOCK	 *locks;
+	PROCLOCK *holders;
+} LockData;
 
 /*
  * function prototypes
@@ -227,6 +242,8 @@ extern void RemoveFromWaitQueue(PGPROC *proc);
 extern int	LockShmemSize(int maxBackends);
 extern bool DeadLockCheck(PGPROC *proc);
 extern void InitDeadLockChecking(void);
+extern void GetLockStatusData(LockData *data);
+extern char *GetLockmodeName(LOCKMODE mode);
 
 #ifdef LOCK_DEBUG
 extern void DumpLocks(void);