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Add built-in userlock manipulation functions to replace the former

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contrib functionality.  Along the way, remove the USER_LOCKS configuration
symbol, since it no longer makes any sense to try to compile that out.
No user documentation yet ... mmoncure has promised to write some.
Thanks to Abhijit Menon-Sen for creating a first draft to work from.
This commit is contained in:
Tom Lane
2006-09-18 22:40:40 +00:00
parent f7f308d6a6
commit 9b4cda0df6
11 changed files with 336 additions and 50 deletions
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260
src/backend/utils/adt/lockfuncs.c
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@ -1,20 +1,21 @@
/*-------------------------------------------------------------------------
*
* lockfuncs.c
* Set-returning functions to view the state of locks within the DB.
* Functions for SQL access to various lock-manager capabilities.
*
* Copyright (c) 2002-2006, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/lockfuncs.c,v 1.24 2006/07/23 23:08:46 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/lockfuncs.c,v 1.25 2006/09/18 22:40:37 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "funcapi.h"
#include "access/heapam.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "storage/proc.h"
#include "utils/builtins.h"
@ -266,3 +267,256 @@ pg_lock_status(PG_FUNCTION_ARGS)
SRF_RETURN_DONE(funcctx);
}
/*
* Functions for manipulating USERLOCK locks
*
* We make use of the locktag fields as follows:
*
* field1: MyDatabaseId ... ensures locks are local to each database
* field2: first of 2 int4 keys, or high-order half of an int8 key
* field3: second of 2 int4 keys, or low-order half of an int8 key
* field4: 1 if using an int8 key, 2 if using 2 int4 keys
*/
#define SET_LOCKTAG_INT64(tag, key64) \
SET_LOCKTAG_USERLOCK(tag, \
MyDatabaseId, \
(uint32) ((key64) >> 32), \
(uint32) (key64), \
1)
#define SET_LOCKTAG_INT32(tag, key1, key2) \
SET_LOCKTAG_USERLOCK(tag, MyDatabaseId, key1, key2, 2)
/*
* pg_advisory_lock(int8) - acquire exclusive lock on an int8 key
*/
Datum
pg_advisory_lock_int8(PG_FUNCTION_ARGS)
{
int64 key = PG_GETARG_INT64(0);
LOCKTAG tag;
SET_LOCKTAG_INT64(tag, key);
(void) LockAcquire(&tag, ExclusiveLock, true, false);
PG_RETURN_VOID();
}
/*
* pg_advisory_lock_shared(int8) - acquire share lock on an int8 key
*/
Datum
pg_advisory_lock_shared_int8(PG_FUNCTION_ARGS)
{
int64 key = PG_GETARG_INT64(0);
LOCKTAG tag;
SET_LOCKTAG_INT64(tag, key);
(void) LockAcquire(&tag, ShareLock, true, false);
PG_RETURN_VOID();
}
/*
* pg_try_advisory_lock(int8) - acquire exclusive lock on an int8 key, no wait
*
* Returns true if successful, false if lock not available
*/
Datum
pg_try_advisory_lock_int8(PG_FUNCTION_ARGS)
{
int64 key = PG_GETARG_INT64(0);
LOCKTAG tag;
LockAcquireResult res;
SET_LOCKTAG_INT64(tag, key);
res = LockAcquire(&tag, ExclusiveLock, true, true);
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
/*
* pg_try_advisory_lock_shared(int8) - acquire share lock on an int8 key, no wait
*
* Returns true if successful, false if lock not available
*/
Datum
pg_try_advisory_lock_shared_int8(PG_FUNCTION_ARGS)
{
int64 key = PG_GETARG_INT64(0);
LOCKTAG tag;
LockAcquireResult res;
SET_LOCKTAG_INT64(tag, key);
res = LockAcquire(&tag, ShareLock, true, true);
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
/*
* pg_advisory_unlock(int8) - release exclusive lock on an int8 key
*
* Returns true if successful, false if lock was not held
*/
Datum
pg_advisory_unlock_int8(PG_FUNCTION_ARGS)
{
int64 key = PG_GETARG_INT64(0);
LOCKTAG tag;
bool res;
SET_LOCKTAG_INT64(tag, key);
res = LockRelease(&tag, ExclusiveLock, true);
PG_RETURN_BOOL(res);
}
/*
* pg_advisory_unlock_shared(int8) - release share lock on an int8 key
*
* Returns true if successful, false if lock was not held
*/
Datum
pg_advisory_unlock_shared_int8(PG_FUNCTION_ARGS)
{
int64 key = PG_GETARG_INT64(0);
LOCKTAG tag;
bool res;
SET_LOCKTAG_INT64(tag, key);
res = LockRelease(&tag, ShareLock, true);
PG_RETURN_BOOL(res);
}
/*
* pg_advisory_lock(int4, int4) - acquire exclusive lock on 2 int4 keys
*/
Datum
pg_advisory_lock_int4(PG_FUNCTION_ARGS)
{
int32 key1 = PG_GETARG_INT32(0);
int32 key2 = PG_GETARG_INT32(1);
LOCKTAG tag;
SET_LOCKTAG_INT32(tag, key1, key2);
(void) LockAcquire(&tag, ExclusiveLock, true, false);
PG_RETURN_VOID();
}
/*
* pg_advisory_lock_shared(int4, int4) - acquire share lock on 2 int4 keys
*/
Datum
pg_advisory_lock_shared_int4(PG_FUNCTION_ARGS)
{
int32 key1 = PG_GETARG_INT32(0);
int32 key2 = PG_GETARG_INT32(1);
LOCKTAG tag;
SET_LOCKTAG_INT32(tag, key1, key2);
(void) LockAcquire(&tag, ShareLock, true, false);
PG_RETURN_VOID();
}
/*
* pg_try_advisory_lock(int4, int4) - acquire exclusive lock on 2 int4 keys, no wait
*
* Returns true if successful, false if lock not available
*/
Datum
pg_try_advisory_lock_int4(PG_FUNCTION_ARGS)
{
int32 key1 = PG_GETARG_INT32(0);
int32 key2 = PG_GETARG_INT32(1);
LOCKTAG tag;
LockAcquireResult res;
SET_LOCKTAG_INT32(tag, key1, key2);
res = LockAcquire(&tag, ExclusiveLock, true, true);
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
/*
* pg_try_advisory_lock_shared(int4, int4) - acquire share lock on 2 int4 keys, no wait
*
* Returns true if successful, false if lock not available
*/
Datum
pg_try_advisory_lock_shared_int4(PG_FUNCTION_ARGS)
{
int32 key1 = PG_GETARG_INT32(0);
int32 key2 = PG_GETARG_INT32(1);
LOCKTAG tag;
LockAcquireResult res;
SET_LOCKTAG_INT32(tag, key1, key2);
res = LockAcquire(&tag, ShareLock, true, true);
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
/*
* pg_advisory_unlock(int4, int4) - release exclusive lock on 2 int4 keys
*
* Returns true if successful, false if lock was not held
*/
Datum
pg_advisory_unlock_int4(PG_FUNCTION_ARGS)
{
int32 key1 = PG_GETARG_INT32(0);
int32 key2 = PG_GETARG_INT32(1);
LOCKTAG tag;
bool res;
SET_LOCKTAG_INT32(tag, key1, key2);
res = LockRelease(&tag, ExclusiveLock, true);
PG_RETURN_BOOL(res);
}
/*
* pg_advisory_unlock_shared(int4, int4) - release share lock on 2 int4 keys
*
* Returns true if successful, false if lock was not held
*/
Datum
pg_advisory_unlock_shared_int4(PG_FUNCTION_ARGS)
{
int32 key1 = PG_GETARG_INT32(0);
int32 key2 = PG_GETARG_INT32(1);
LOCKTAG tag;
bool res;
SET_LOCKTAG_INT32(tag, key1, key2);
res = LockRelease(&tag, ShareLock, true);
PG_RETURN_BOOL(res);
}
/*
* pg_advisory_unlock_all() - release all userlocks
*/
Datum
pg_advisory_unlock_all(PG_FUNCTION_ARGS)
{
LockReleaseAll(USER_LOCKMETHOD, true);
PG_RETURN_VOID();
}