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