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/*
* user_locks.c --
*
* This loadable module, together with my user-lock.patch applied to the
* backend, provides support for user-level long-term cooperative locks.
*
* Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it>
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "postgres.h"
#include "miscadmin.h"
#include "storage/lock.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
#include "storage/block.h"
#include "storage/multilev.h"
#include "utils/elog.h"
#include "user_locks.h"
#define USER_LOCKS_TABLE_ID 0
extern Oid MyDatabaseId;
int
user_lock(unsigned int id1, unsigned int id2, LOCKT lockt)
{
LOCKTAG tag;
memset(&tag,0,sizeof(LOCKTAG));
tag.relId = 0;
tag.dbId = MyDatabaseId;
tag.tupleId.ip_blkid.bi_hi = id2 >> 16;
tag.tupleId.ip_blkid.bi_lo = id2 & 0xffff;
tag.tupleId.ip_posid = (unsigned short) (id1 & 0xffff);
return LockAcquire(USER_LOCKS_TABLE_ID, &tag, lockt);
}
int
user_unlock(unsigned int id1, unsigned int id2, LOCKT lockt)
{
LOCKTAG tag;
memset(&tag, 0,sizeof(LOCKTAG));
tag.relId = 0;
tag.dbId = MyDatabaseId;
tag.tupleId.ip_blkid.bi_hi = id2 >> 16;
tag.tupleId.ip_blkid.bi_lo = id2 & 0xffff;
tag.tupleId.ip_posid = (unsigned short) (id1 & 0xffff);
return LockRelease(USER_LOCKS_TABLE_ID, &tag, lockt);
}
int
user_write_lock(unsigned int id1, unsigned int id2)
{
return user_lock(id1, id2, WRITE_LOCK);
}
int
user_write_unlock(unsigned int id1, unsigned int id2)
{
return user_unlock(id1, id2, WRITE_LOCK);
}
int
user_write_lock_oid(Oid oid)
{
return user_lock(0, oid, WRITE_LOCK);
}
int
user_write_unlock_oid(Oid oid)
{
return user_unlock(0, oid, WRITE_LOCK);
}
int
user_unlock_all()
{
PROC *proc;
SHMEM_OFFSET location;
ShmemPIDLookup(getpid(),&location);
if (location == INVALID_OFFSET) {
elog(NOTICE, "UserUnlockAll: unable to get proc ptr");
return -1;
}
proc = (PROC *) MAKE_PTR(location);
return LockReleaseAll(USER_LOCKS_TABLE_ID, &proc->lockQueue);
}
/* end of file */
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