pg_advisory_lock(key bigint)
void
- Obtain exclusive advisory lock
+ Obtain exclusive session level advisory lock
|
pg_advisory_lock(key1 int, key2 int)
void
- Obtain exclusive advisory lock
+ Obtain exclusive session level advisory lock
|
pg_advisory_lock_shared(key bigint)
void
- Obtain shared advisory lock
+ Obtain shared session level advisory lock
|
pg_advisory_lock_shared(key1 int, key2 int)
void
- Obtain shared advisory lock
+ Obtain shared session level advisory lock
|
pg_advisory_unlock(key bigint)
boolean
- Release an exclusive advisory lock
+ Release an exclusive session level advisory lock
|
pg_advisory_unlock(key1 int, key2 int)
boolean
- Release an exclusive advisory lock
+ Release an exclusive session level advisory lock
|
pg_advisory_unlock_all()
void
- Release all advisory locks held by the current session
+ Release all session level advisory locks held by the current session
|
pg_advisory_unlock_shared(key bigint)
boolean
- Release a shared advisory lock
+ Release a shared session level advisory lock
|
pg_advisory_unlock_shared(key1 int, key2 int)
boolean
- Release a shared advisory lock
+ Release a shared session level advisory lock
+
+ |
+
+
pg_advisory_xact_lock(key bigint)+
+ void
+ Obtain exclusive transaction level advisory lock
+
+ |
+
+
pg_advisory_xact_lock(key1 int, key2 int)+
+ void
+ Obtain exclusive transaction level advisory lock
+
+ |
+
+
pg_advisory_xact_lock_shared(key bigint)+
+ void
+ Obtain shared transaction level advisory lock
+
+ |
+
+
pg_advisory_xact_lock_shared(key1 int, key2 int)+
+ void
+ Obtain shared advisory lock for the current transaction
|
pg_try_advisory_lock(key bigint)
boolean
- Obtain exclusive advisory lock if available
+ Obtain exclusive session level advisory lock if available
|
pg_try_advisory_lock(key1 int, key2 int)
boolean
- Obtain exclusive advisory lock if available
+ Obtain exclusive session level advisory lock if available
|
pg_try_advisory_lock_shared(key bigint)
boolean
- Obtain shared advisory lock if available
+ Obtain shared session level advisory lock if available
|
pg_try_advisory_lock_shared(key1 int, key2 int)
boolean
- Obtain shared advisory lock if available
+ Obtain shared session level advisory lock if available
+
+ |
+
+
pg_try_advisory_xact_lock(key bigint)+
+ boolean
+ Obtain exclusive transaction level advisory lock if available
+
+ |
+
+
pg_try_advisory_xact_lock(key1 int, key2 int)+
+ boolean
+ Obtain exclusive transaction level advisory lock if available
+
+ |
+
+
pg_try_advisory_xact_lock_shared(key bigint)+
+ boolean
+ Obtain shared transaction level advisory lock if available
+
+ |
+
+
pg_try_advisory_xact_lock_shared(key1 int, key2 int)+
+ boolean
+ Obtain shared transaction level advisory lock if available
a shared rather than an exclusive lock.
+
+
+ pg_advisory_xact_lock works the same as
+ pg_advisory_lock, expect the lock is automatically released
+ at the end of the current transaction and can not be released explicitly.
+
+
+
+
pg_advisory_xact_lock_shared+
+ pg_advisory_xact_lock_shared works the same as
+ pg_advisory_lock_shared, expect the lock is automatically released
+ at the end of the current transaction and can not be released explicitly.
+
+
+
+
pg_try_advisory_xact_lock+
+ pg_try_advisory_xact_lock works the same as
+ pg_try_advisory_lock, expect the lock, if acquired,
+ is automatically released at the end of the current transaction and
+ can not be released explicitly.
+
+
+
+
pg_try_advisory_xact_lock_shared+
+ pg_try_advisory_xact_lock_shared works the same as
+ pg_try_advisory_lock_shared, expect the lock, if acquired,
+ is automatically released at the end of the current transaction and
+ can not be released explicitly.
+
+
pg_advisory_unlock will release a previously-acquired
- exclusive advisory lock. It
+ exclusive session level advisory lock. It
returns true if the lock is successfully released.
If the lock was not held, it will return false,
and in addition, an SQL warning will be raised by the server.
pg_advisory_unlock_shared works the same as
pg_advisory_unlock,
- except it releases a shared advisory lock.
+ except it releases a shared session level advisory lock.
- pg_advisory_unlock_all will release all advisory locks
- held by the current session. (This function is implicitly invoked
+ pg_advisory_unlock_all will release all session level advisory
+ locks held by the current session. (This function is implicitly invoked
at session end, even if the client disconnects ungracefully.)
called advisory locks, because the system does not
enforce their use — it is up to the application to use them
correctly. Advisory locks can be useful for locking strategies
- that are an awkward fit for the MVCC model. Once acquired, an
- advisory lock is held until explicitly released or the session ends.
- Unlike standard locks, advisory locks do not
- honor transaction semantics: a lock acquired during a
- transaction that is later rolled back will still be held following the
+ that are an awkward fit for the MVCC model.
+
+ There are two different types of advisory locks in
+
PostgreSQL: session level and transaction level.
+ Once acquired, a session level advisory lock is held until explicitly
+ released or the session ends. Unlike standard locks, session level
+ advisory locks do not honor transaction semantics: a lock acquired during
+ a transaction that is later rolled back will still be held following the
rollback, and likewise an unlock is effective even if the calling
- transaction fails later. The same lock can be acquired multiple times by
- its owning process: for each lock request there must be a corresponding
- unlock request before the lock is actually released. (If a session
- already holds a given lock, additional requests will always succeed, even
- if other sessions are awaiting the lock.) Like all locks in
-
PostgreSQL, a complete list of advisory
- locks currently held by any session can be found in the
+ transaction fails later. The same session level lock can be acquired
+ multiple times by its owning process: for each lock request there must be
+ a corresponding unlock request before the lock is actually released. (If a
+ session already holds a given lock, additional requests will always succeed,
+ even if other sessions are awaiting the lock.) Transaction level locks on
+ the other hand behave more like regular locks; they are automatically
+ released at the end of the transaction, and can not be explicitly unlocked.
+ Session and transaction level locks share the same lock space, which means
+ that a transaction level lock will prevent another session from obtaining
+ a session level lock on that same resource and vice versa.
+ Like all locks in
PostgreSQL, a complete list of
+ advisory locks currently held by any session can be found in the
pg_locks
system view.
strategies typical of so called flat file data management
systems.
While a flag stored in a table could be used for the same purpose,
- advisory locks are faster, avoid MVCC bloat, and are automatically
+ advisory locks are faster, avoid MVCC bloat, and can be automatically
cleaned up by the server at the end of the session.
In certain cases using this advisory locking method, especially in queries
involving explicit ordering and LIMIT clauses, care must be
----------
User locks are handled totally on the application side as long term
-cooperative locks which extend beyond the normal transaction boundaries.
+cooperative locks which may extend beyond the normal transaction boundaries.
Their purpose is to indicate to an application that someone is `working'
on an item. So it is possible to put an user lock on a tuple's oid,
retrieve the tuple, work on it for an hour and then update it and remove
User locks and normal locks are completely orthogonal and they don't
interfere with each other.
-User locks are always held as session locks, so that they are not released at
-transaction end. They must be released explicitly by the application --- but
-they are released automatically when a backend terminates.
+There are two types of user locks: session level and transaction level.
+Session level user locks are not released at transaction end. They must
+be released explicitly by the application --- but they are released
+automatically when a backend terminates. On the other hand, transaction
+level user locks are released automatically at the end of the transaction
+as like as other normal locks.
Locking during Hot Standby
--------------------------
static const LockMethodData user_lockmethod = {
AccessExclusiveLock, /* highest valid lock mode number */
- false,
+ true,
LockConflicts,
lock_mode_names,
#ifdef LOCK_DEBUG
static void RemoveLocalLock(LOCALLOCK *locallock);
static void GrantLockLocal(LOCALLOCK *locallock, ResourceOwner owner);
static void WaitOnLock(LOCALLOCK *locallock, ResourceOwner owner);
+static void ReleaseLockForOwner(LOCALLOCK *locallock, ResourceOwner owner);
static bool UnGrantLock(LOCK *lock, LOCKMODE lockmode,
PROCLOCK *proclock, LockMethod lockMethodTable);
static void CleanUpLock(LOCK *lock, PROCLOCK *proclock,
return TRUE;
}
+/*
+ * LockReleaseSession -- Release all session locks of the specified lock method
+ * that are held by the current process.
+ */
+void
+LockReleaseSession(LOCKMETHODID lockmethodid)
+{
+ HASH_SEQ_STATUS status;
+ LOCALLOCK *locallock;
+
+ if (lockmethodid <= 0 || lockmethodid >= lengthof(LockMethods))
+ elog(ERROR, "unrecognized lock method: %d", lockmethodid);
+
+ hash_seq_init(&status, LockMethodLocalHash);
+
+ while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+ {
+ /* Ignore items that are not of the specified lock method */
+ if (LOCALLOCK_LOCKMETHOD(*locallock) != lockmethodid)
+ continue;
+
+ ReleaseLockForOwner(locallock, NULL);
+ }
+}
+
/*
* LockReleaseAll -- Release all locks of the specified lock method that
* are held by the current process.
{
HASH_SEQ_STATUS status;
LOCALLOCK *locallock;
- LOCALLOCKOWNER *lockOwners;
- int i;
hash_seq_init(&status, LockMethodLocalHash);
if (!LockMethods[LOCALLOCK_LOCKMETHOD(*locallock)]->transactional)
continue;
- /* Scan to see if there are any locks belonging to current owner */
- lockOwners = locallock->lockOwners;
- for (i = locallock->numLockOwners - 1; i >= 0; i--)
+ ReleaseLockForOwner(locallock, CurrentResourceOwner);
+ }
+}
+
+/*
+ * Subroutine to release a lock belonging to the 'owner' if found.
+ * 'owner' can be NULL to release a session lock.
+ */
+static void
+ReleaseLockForOwner(LOCALLOCK *locallock, ResourceOwner owner)
+{
+ int i;
+ LOCALLOCKOWNER *lockOwners;
+
+ /* Scan to see if there are any locks belonging to the owner */
+ lockOwners = locallock->lockOwners;
+ for (i = locallock->numLockOwners - 1; i >= 0; i--)
+ {
+ if (lockOwners[i].owner == owner)
{
- if (lockOwners[i].owner == CurrentResourceOwner)
+ Assert(lockOwners[i].nLocks > 0);
+ if (lockOwners[i].nLocks < locallock->nLocks)
{
- Assert(lockOwners[i].nLocks > 0);
- if (lockOwners[i].nLocks < locallock->nLocks)
- {
- /*
- * We will still hold this lock after forgetting this
- * ResourceOwner.
- */
- locallock->nLocks -= lockOwners[i].nLocks;
- /* compact out unused slot */
- locallock->numLockOwners--;
- if (i < locallock->numLockOwners)
- lockOwners[i] = lockOwners[locallock->numLockOwners];
- }
- else
- {
- Assert(lockOwners[i].nLocks == locallock->nLocks);
- /* We want to call LockRelease just once */
- lockOwners[i].nLocks = 1;
- locallock->nLocks = 1;
- if (!LockRelease(&locallock->tag.lock,
- locallock->tag.mode,
- false))
- elog(WARNING, "LockReleaseCurrentOwner: failed??");
- }
- break;
+ /*
+ * We will still hold this lock after forgetting this
+ * ResourceOwner.
+ */
+ locallock->nLocks -= lockOwners[i].nLocks;
+ /* compact out unused slot */
+ locallock->numLockOwners--;
+ if (i < locallock->numLockOwners)
+ lockOwners[i] = lockOwners[locallock->numLockOwners];
+ }
+ else
+ {
+ Assert(lockOwners[i].nLocks == locallock->nLocks);
+ /* We want to call LockRelease just once */
+ lockOwners[i].nLocks = 1;
+ locallock->nLocks = 1;
+ if (!LockRelease(&locallock->tag.lock,
+ locallock->tag.mode,
+ owner == NULL))
+ elog(WARNING, "ReleaseLockForOwner: failed??");
}
+ break;
}
}
}
* At subtransaction abort, we release all locks held by the subtransaction;
* this is implemented by retail releasing of the locks under control of
* the ResourceOwner mechanism.
- *
- * Note that user locks are not released in any case.
*/
void
ProcReleaseLocks(bool isCommit)
LockWaitCancel();
/* Release locks */
LockReleaseAll(DEFAULT_LOCKMETHOD, !isCommit);
+
+ /* Release transaction level advisory locks */
+ LockReleaseAll(USER_LOCKMETHOD, false);
}
PG_RETURN_VOID();
}
+/*
+ * pg_advisory_xact_lock(int8) - acquire xact scoped
+ * exclusive lock on an int8 key
+ */
+Datum
+pg_advisory_xact_lock_int8(PG_FUNCTION_ARGS)
+{
+ int64 key = PG_GETARG_INT64(0);
+ LOCKTAG tag;
+
+ SET_LOCKTAG_INT64(tag, key);
+
+ (void) LockAcquire(&tag, ExclusiveLock, false, false);
+
+ PG_RETURN_VOID();
+}
+
/*
* pg_advisory_lock_shared(int8) - acquire share lock on an int8 key
*/
PG_RETURN_VOID();
}
+/*
+ * pg_advisory_xact_lock_shared(int8) - acquire xact scoped
+ * share lock on an int8 key
+ */
+Datum
+pg_advisory_xact_lock_shared_int8(PG_FUNCTION_ARGS)
+{
+ int64 key = PG_GETARG_INT64(0);
+ LOCKTAG tag;
+
+ SET_LOCKTAG_INT64(tag, key);
+
+ (void) LockAcquire(&tag, ShareLock, false, false);
+
+ PG_RETURN_VOID();
+}
+
/*
* pg_try_advisory_lock(int8) - acquire exclusive lock on an int8 key, no wait
*
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
+/*
+ * pg_try_advisory_xact_lock(int8) - acquire xact scoped
+ * exclusive lock on an int8 key, no wait
+ *
+ * Returns true if successful, false if lock not available
+ */
+Datum
+pg_try_advisory_xact_lock_int8(PG_FUNCTION_ARGS)
+{
+ int64 key = PG_GETARG_INT64(0);
+ LOCKTAG tag;
+ LockAcquireResult res;
+
+ SET_LOCKTAG_INT64(tag, key);
+
+ res = LockAcquire(&tag, ExclusiveLock, false, true);
+
+ PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
+}
+
/*
* pg_try_advisory_lock_shared(int8) - acquire share lock on an int8 key, no wait
*
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
+/*
+ * pg_try_advisory_xact_lock_shared(int8) - acquire xact scoped
+ * share lock on an int8 key, no wait
+ *
+ * Returns true if successful, false if lock not available
+ */
+Datum
+pg_try_advisory_xact_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, false, true);
+
+ PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
+}
+
/*
* pg_advisory_unlock(int8) - release exclusive lock on an int8 key
*
PG_RETURN_VOID();
}
+/*
+ * pg_advisory_xact_lock(int4, int4) - acquire xact scoped
+ * exclusive lock on 2 int4 keys
+ */
+Datum
+pg_advisory_xact_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, false, false);
+
+ PG_RETURN_VOID();
+}
+
/*
* pg_advisory_lock_shared(int4, int4) - acquire share lock on 2 int4 keys
*/
PG_RETURN_VOID();
}
+/*
+ * pg_advisory_xact_lock_shared(int4, int4) - acquire xact scoped
+ * share lock on 2 int4 keys
+ */
+Datum
+pg_advisory_xact_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, false, false);
+
+ PG_RETURN_VOID();
+}
+
/*
* pg_try_advisory_lock(int4, int4) - acquire exclusive lock on 2 int4 keys, no wait
*
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
+/*
+ * pg_try_advisory_xact_lock(int4, int4) - acquire xact scoped
+ * exclusive lock on 2 int4 keys, no wait
+ *
+ * Returns true if successful, false if lock not available
+ */
+Datum
+pg_try_advisory_xact_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, false, true);
+
+ PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
+}
+
/*
* pg_try_advisory_lock_shared(int4, int4) - acquire share lock on 2 int4 keys, no wait
*
PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}
+/*
+ * pg_try_advisory_xact_lock_shared(int4, int4) - acquire xact scoped
+ * share lock on 2 int4 keys, no wait
+ *
+ * Returns true if successful, false if lock not available
+ */
+Datum
+pg_try_advisory_xact_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, false, true);
+
+ PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
+}
+
/*
* pg_advisory_unlock(int4, int4) - release exclusive lock on 2 int4 keys
*
Datum
pg_advisory_unlock_all(PG_FUNCTION_ARGS)
{
- LockReleaseAll(USER_LOCKMETHOD, true);
+ LockReleaseSession(USER_LOCKMETHOD);
PG_RETURN_VOID();
}
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201102171
+#define CATALOG_VERSION_NO 201102181
#endif
/* userlock replacements */
DATA(insert OID = 2880 ( pg_advisory_lock PGNSP PGUID 12 1 0 0 f f f t f v 1 0 2278 "20" _null_ _null_ _null_ _null_ pg_advisory_lock_int8 _null_ _null_ _null_ ));
+DESCR("obtain exclusive a4dvisory lock");
+DATA(insert OID = 3089 ( pg_advisory_xact_lock PGNSP PGUID 12 1 0 0 f f f t f v 1 0 2278 "20" _null_ _null_ _null_ _null_ pg_advisory_xact_lock_int8 _null_ _null_ _null_ ));
DESCR("obtain exclusive advisory lock");
DATA(insert OID = 2881 ( pg_advisory_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 1 0 2278 "20" _null_ _null_ _null_ _null_ pg_advisory_lock_shared_int8 _null_ _null_ _null_ ));
DESCR("obtain shared advisory lock");
+DATA(insert OID = 3090 ( pg_advisory_xact_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 1 0 2278 "20" _null_ _null_ _null_ _null_ pg_advisory_xact_lock_shared_int8 _null_ _null_ _null_ ));
+DESCR("obtain shared advisory lock");
DATA(insert OID = 2882 ( pg_try_advisory_lock PGNSP PGUID 12 1 0 0 f f f t f v 1 0 16 "20" _null_ _null_ _null_ _null_ pg_try_advisory_lock_int8 _null_ _null_ _null_ ));
DESCR("obtain exclusive advisory lock if available");
+DATA(insert OID = 3091 ( pg_try_advisory_xact_lock PGNSP PGUID 12 1 0 0 f f f t f v 1 0 16 "20" _null_ _null_ _null_ _null_ pg_try_advisory_xact_lock_int8 _null_ _null_ _null_ ));
+DESCR("obtain exclusive advisory lock if available");
DATA(insert OID = 2883 ( pg_try_advisory_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 1 0 16 "20" _null_ _null_ _null_ _null_ pg_try_advisory_lock_shared_int8 _null_ _null_ _null_ ));
DESCR("obtain shared advisory lock if available");
+DATA(insert OID = 3092 ( pg_try_advisory_xact_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 1 0 16 "20" _null_ _null_ _null_ _null_ pg_try_advisory_xact_lock_shared_int8 _null_ _null_ _null_ ));
+DESCR("obtain shared advisory lock if available");
DATA(insert OID = 2884 ( pg_advisory_unlock PGNSP PGUID 12 1 0 0 f f f t f v 1 0 16 "20" _null_ _null_ _null_ _null_ pg_advisory_unlock_int8 _null_ _null_ _null_ ));
DESCR("release exclusive advisory lock");
DATA(insert OID = 2885 ( pg_advisory_unlock_shared PGNSP PGUID 12 1 0 0 f f f t f v 1 0 16 "20" _null_ _null_ _null_ _null_ pg_advisory_unlock_shared_int8 _null_ _null_ _null_ ));
DESCR("release shared advisory lock");
DATA(insert OID = 2886 ( pg_advisory_lock PGNSP PGUID 12 1 0 0 f f f t f v 2 0 2278 "23 23" _null_ _null_ _null_ _null_ pg_advisory_lock_int4 _null_ _null_ _null_ ));
DESCR("obtain exclusive advisory lock");
+DATA(insert OID = 3093 ( pg_advisory_xact_lock PGNSP PGUID 12 1 0 0 f f f t f v 2 0 2278 "23 23" _null_ _null_ _null_ _null_ pg_advisory_xact_lock_int4 _null_ _null_ _null_ ));
+DESCR("obtain exclusive advisory lock");
DATA(insert OID = 2887 ( pg_advisory_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 2 0 2278 "23 23" _null_ _null_ _null_ _null_ pg_advisory_lock_shared_int4 _null_ _null_ _null_ ));
DESCR("obtain shared advisory lock");
+DATA(insert OID = 3094 ( pg_advisory_xact_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 2 0 2278 "23 23" _null_ _null_ _null_ _null_ pg_advisory_xact_lock_shared_int4 _null_ _null_ _null_ ));
+DESCR("obtain shared advisory lock");
DATA(insert OID = 2888 ( pg_try_advisory_lock PGNSP PGUID 12 1 0 0 f f f t f v 2 0 16 "23 23" _null_ _null_ _null_ _null_ pg_try_advisory_lock_int4 _null_ _null_ _null_ ));
DESCR("obtain exclusive advisory lock if available");
+DATA(insert OID = 3095 ( pg_try_advisory_xact_lock PGNSP PGUID 12 1 0 0 f f f t f v 2 0 16 "23 23" _null_ _null_ _null_ _null_ pg_try_advisory_xact_lock_int4 _null_ _null_ _null_ ));
+DESCR("obtain exclusive advisory lock if available");
DATA(insert OID = 2889 ( pg_try_advisory_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 2 0 16 "23 23" _null_ _null_ _null_ _null_ pg_try_advisory_lock_shared_int4 _null_ _null_ _null_ ));
DESCR("obtain shared advisory lock if available");
+DATA(insert OID = 3096 ( pg_try_advisory_xact_lock_shared PGNSP PGUID 12 1 0 0 f f f t f v 2 0 16 "23 23" _null_ _null_ _null_ _null_ pg_try_advisory_xact_lock_shared_int4 _null_ _null_ _null_ ));
+DESCR("obtain shared advisory lock if available");
DATA(insert OID = 2890 ( pg_advisory_unlock PGNSP PGUID 12 1 0 0 f f f t f v 2 0 16 "23 23" _null_ _null_ _null_ _null_ pg_advisory_unlock_int4 _null_ _null_ _null_ ));
DESCR("release exclusive advisory lock");
DATA(insert OID = 2891 ( pg_advisory_unlock_shared PGNSP PGUID 12 1 0 0 f f f t f v 2 0 16 "23 23" _null_ _null_ _null_ _null_ pg_advisory_unlock_shared_int4 _null_ _null_ _null_ ));
bool report_memory_error);
extern bool LockRelease(const LOCKTAG *locktag,
LOCKMODE lockmode, bool sessionLock);
+extern void LockReleaseSession(LOCKMETHODID lockmethodid);
extern void LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks);
extern void LockReleaseCurrentOwner(void);
extern void LockReassignCurrentOwner(void);
/* lockfuncs.c */
extern Datum pg_lock_status(PG_FUNCTION_ARGS);
extern Datum pg_advisory_lock_int8(PG_FUNCTION_ARGS);
+extern Datum pg_advisory_xact_lock_int8(PG_FUNCTION_ARGS);
extern Datum pg_advisory_lock_shared_int8(PG_FUNCTION_ARGS);
+extern Datum pg_advisory_xact_lock_shared_int8(PG_FUNCTION_ARGS);
extern Datum pg_try_advisory_lock_int8(PG_FUNCTION_ARGS);
+extern Datum pg_try_advisory_xact_lock_int8(PG_FUNCTION_ARGS);
extern Datum pg_try_advisory_lock_shared_int8(PG_FUNCTION_ARGS);
+extern Datum pg_try_advisory_xact_lock_shared_int8(PG_FUNCTION_ARGS);
extern Datum pg_advisory_unlock_int8(PG_FUNCTION_ARGS);
extern Datum pg_advisory_unlock_shared_int8(PG_FUNCTION_ARGS);
extern Datum pg_advisory_lock_int4(PG_FUNCTION_ARGS);
+extern Datum pg_advisory_xact_lock_int4(PG_FUNCTION_ARGS);
extern Datum pg_advisory_lock_shared_int4(PG_FUNCTION_ARGS);
+extern Datum pg_advisory_xact_lock_shared_int4(PG_FUNCTION_ARGS);
extern Datum pg_try_advisory_lock_int4(PG_FUNCTION_ARGS);
+extern Datum pg_try_advisory_xact_lock_int4(PG_FUNCTION_ARGS);
extern Datum pg_try_advisory_lock_shared_int4(PG_FUNCTION_ARGS);
+extern Datum pg_try_advisory_xact_lock_shared_int4(PG_FUNCTION_ARGS);
extern Datum pg_advisory_unlock_int4(PG_FUNCTION_ARGS);
extern Datum pg_advisory_unlock_shared_int4(PG_FUNCTION_ARGS);
extern Datum pg_advisory_unlock_all(PG_FUNCTION_ARGS);
--- /dev/null
+--
+-- ADVISORY LOCKS
+--
+BEGIN;
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
+ pg_advisory_xact_lock | pg_advisory_xact_lock_shared | pg_advisory_xact_lock | pg_advisory_xact_lock_shared
+-----------------------+------------------------------+-----------------------+------------------------------
+ | | |
+(1 row)
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+-- pg_advisory_unlock_all() shouldn't release xact locks
+SELECT pg_advisory_unlock_all();
+ pg_advisory_unlock_all
+------------------------
+
+(1 row)
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 4
+(1 row)
+
+-- can't unlock xact locks
+SELECT
+ pg_advisory_unlock(1), pg_advisory_unlock_shared(2),
+ pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2);
+WARNING: you don't own a lock of type ExclusiveLock
+WARNING: you don't own a lock of type ShareLock
+WARNING: you don't own a lock of type ExclusiveLock
+WARNING: you don't own a lock of type ShareLock
+ pg_advisory_unlock | pg_advisory_unlock_shared | pg_advisory_unlock | pg_advisory_unlock_shared
+--------------------+---------------------------+--------------------+---------------------------
+ f | f | f | f
+(1 row)
+
+-- automatically release xact locks at commit
+COMMIT;
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+-- holding both session and xact locks on the same objects, xact first
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
+ pg_advisory_xact_lock | pg_advisory_xact_lock_shared | pg_advisory_xact_lock | pg_advisory_xact_lock_shared
+-----------------------+------------------------------+-----------------------+------------------------------
+ | | |
+(1 row)
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
+ pg_advisory_lock | pg_advisory_lock_shared | pg_advisory_lock | pg_advisory_lock_shared
+------------------+-------------------------+------------------+-------------------------
+ | | |
+(1 row)
+
+ROLLBACK;
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+-- unlocking session locks
+SELECT
+ pg_advisory_unlock(1), pg_advisory_unlock(1),
+ pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
+ pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
+ pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
+WARNING: you don't own a lock of type ExclusiveLock
+WARNING: you don't own a lock of type ShareLock
+WARNING: you don't own a lock of type ExclusiveLock
+WARNING: you don't own a lock of type ShareLock
+ pg_advisory_unlock | pg_advisory_unlock | pg_advisory_unlock_shared | pg_advisory_unlock_shared | pg_advisory_unlock | pg_advisory_unlock | pg_advisory_unlock_shared | pg_advisory_unlock_shared
+--------------------+--------------------+---------------------------+---------------------------+--------------------+--------------------+---------------------------+---------------------------
+ t | f | t | f | t | f | t | f
+(1 row)
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+-- holding both session and xact locks on the same objects, session first
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
+ pg_advisory_lock | pg_advisory_lock_shared | pg_advisory_lock | pg_advisory_lock_shared
+------------------+-------------------------+------------------+-------------------------
+ | | |
+(1 row)
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
+ pg_advisory_xact_lock | pg_advisory_xact_lock_shared | pg_advisory_xact_lock | pg_advisory_xact_lock_shared
+-----------------------+------------------------------+-----------------------+------------------------------
+ | | |
+(1 row)
+
+ROLLBACK;
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+-- releasing all session locks
+SELECT pg_advisory_unlock_all();
+ pg_advisory_unlock_all
+------------------------
+
+(1 row)
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+-- grabbing txn locks multiple times
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock(1),
+ pg_advisory_xact_lock_shared(2), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock(1, 1),
+ pg_advisory_xact_lock_shared(2, 2), pg_advisory_xact_lock_shared(2, 2);
+ pg_advisory_xact_lock | pg_advisory_xact_lock | pg_advisory_xact_lock_shared | pg_advisory_xact_lock_shared | pg_advisory_xact_lock | pg_advisory_xact_lock | pg_advisory_xact_lock_shared | pg_advisory_xact_lock_shared
+-----------------------+-----------------------+------------------------------+------------------------------+-----------------------+-----------------------+------------------------------+------------------------------
+ | | | | | | |
+(1 row)
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+COMMIT;
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 0
+(1 row)
+
+-- grabbing session locks multiple times
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock(1),
+ pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
+ pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
+ pg_advisory_lock | pg_advisory_lock | pg_advisory_lock_shared | pg_advisory_lock_shared | pg_advisory_lock | pg_advisory_lock | pg_advisory_lock_shared | pg_advisory_lock_shared
+------------------+------------------+-------------------------+-------------------------+------------------+------------------+-------------------------+-------------------------
+ | | | | | | |
+(1 row)
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+SELECT
+ pg_advisory_unlock(1), pg_advisory_unlock(1),
+ pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
+ pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
+ pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
+ pg_advisory_unlock | pg_advisory_unlock | pg_advisory_unlock_shared | pg_advisory_unlock_shared | pg_advisory_unlock | pg_advisory_unlock | pg_advisory_unlock_shared | pg_advisory_unlock_shared
+--------------------+--------------------+---------------------------+---------------------------+--------------------+--------------------+---------------------------+---------------------------
+ t | t | t | t | t | t | t | t
+(1 row)
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 0
+(1 row)
+
+-- .. and releasing them all at once
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock(1),
+ pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
+ pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
+ pg_advisory_lock | pg_advisory_lock | pg_advisory_lock_shared | pg_advisory_lock_shared | pg_advisory_lock | pg_advisory_lock | pg_advisory_lock_shared | pg_advisory_lock_shared
+------------------+------------------+-------------------------+-------------------------+------------------+------------------+-------------------------+-------------------------
+ | | | | | | |
+(1 row)
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+ locktype | classid | objid | objsubid | mode | granted
+----------+---------+-------+----------+---------------+---------
+ advisory | 0 | 1 | 1 | ExclusiveLock | t
+ advisory | 0 | 2 | 1 | ShareLock | t
+ advisory | 1 | 1 | 2 | ExclusiveLock | t
+ advisory | 2 | 2 | 2 | ShareLock | t
+(4 rows)
+
+SELECT pg_advisory_unlock_all();
+ pg_advisory_unlock_all
+------------------------
+
+(1 row)
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+ count
+-------
+ 0
+(1 row)
+
# ----------
# Another group of parallel tests
# ----------
-test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps
+test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock
# ----------
# Another group of parallel tests
test: window
test: xmlmap
test: functional_deps
+test: advisory_lock
test: plancache
test: limit
test: plpgsql
--- /dev/null
+--
+-- ADVISORY LOCKS
+--
+
+BEGIN;
+
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+
+-- pg_advisory_unlock_all() shouldn't release xact locks
+SELECT pg_advisory_unlock_all();
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+
+
+-- can't unlock xact locks
+SELECT
+ pg_advisory_unlock(1), pg_advisory_unlock_shared(2),
+ pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2);
+
+
+-- automatically release xact locks at commit
+COMMIT;
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+
+
+BEGIN;
+
+-- holding both session and xact locks on the same objects, xact first
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
+
+ROLLBACK;
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+
+-- unlocking session locks
+SELECT
+ pg_advisory_unlock(1), pg_advisory_unlock(1),
+ pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
+ pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
+ pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+
+
+BEGIN;
+
+-- holding both session and xact locks on the same objects, session first
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
+
+ROLLBACK;
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+
+-- releasing all session locks
+SELECT pg_advisory_unlock_all();
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+
+
+BEGIN;
+
+-- grabbing txn locks multiple times
+
+SELECT
+ pg_advisory_xact_lock(1), pg_advisory_xact_lock(1),
+ pg_advisory_xact_lock_shared(2), pg_advisory_xact_lock_shared(2),
+ pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock(1, 1),
+ pg_advisory_xact_lock_shared(2, 2), pg_advisory_xact_lock_shared(2, 2);
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+COMMIT;
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+
+-- grabbing session locks multiple times
+
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock(1),
+ pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
+ pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+SELECT
+ pg_advisory_unlock(1), pg_advisory_unlock(1),
+ pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
+ pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
+ pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
+
+-- .. and releasing them all at once
+
+SELECT
+ pg_advisory_lock(1), pg_advisory_lock(1),
+ pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
+ pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
+ pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
+
+SELECT locktype, classid, objid, objsubid, mode, granted
+ FROM pg_locks WHERE locktype = 'advisory'
+ ORDER BY classid, objid, objsubid;
+
+SELECT pg_advisory_unlock_all();
+
+SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
projects / postgresql.git / commitdiff