diff options
Diffstat (limited to 'src/include/storage/lock.h')
| -rw-r--r-- | src/include/storage/lock.h | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h index 8c7159c0cb0..650b3269497 100644 --- a/src/include/storage/lock.h +++ b/src/include/storage/lock.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.77 2004/05/28 05:13:29 tgl Exp $ + * $PostgreSQL: pgsql/src/include/storage/lock.h,v 1.78 2004/07/01 00:51:43 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -26,6 +26,14 @@ typedef struct PROC_QUEUE int size; /* number of entries in list */ } PROC_QUEUE; +/* Release options for LockReleaseAll */ +typedef enum +{ + ReleaseAll, /* All my locks */ + ReleaseAllExceptSession, /* All except session locks (Xid = 0) */ + ReleaseGivenXids /* Only locks with Xids in given array */ +} LockReleaseWhich; + /* struct PGPROC is declared in storage/proc.h, but must forward-reference it */ typedef struct PGPROC PGPROC; @@ -165,11 +173,12 @@ typedef struct LOCK * * There are two possible kinds of proclock tags: a transaction (identified * both by the PGPROC of the backend running it, and the xact's own ID) and - * a session (identified by backend PGPROC, with xid = InvalidTransactionId). + * a session (identified by backend PGPROC, with XID = InvalidTransactionId). * * Currently, session proclocks are used for user locks and for cross-xact - * locks obtained for VACUUM. We assume that a session lock never conflicts - * with per-transaction locks obtained by the same backend. + * locks obtained for VACUUM. Note that a single backend can hold locks + * under several different XIDs at once (including session locks). We treat + * such locks as never conflicting (a backend can never block itself). * * The holding[] array counts the granted locks (of each type) represented * by this proclock. Note that there will be a proclock object, possibly with @@ -177,11 +186,11 @@ typedef struct LOCK * Otherwise, proclock objects whose counts have gone to zero are recycled * as soon as convenient. * - * Each PROCLOCK object is linked into lists for both the associated LOCK object - * and the owning PGPROC object. Note that the PROCLOCK is entered into these - * lists as soon as it is created, even if no lock has yet been granted. - * A PGPROC that is waiting for a lock to be granted will also be linked into - * the lock's waitProcs queue. + * Each PROCLOCK object is linked into lists for both the associated LOCK + * object and the owning PGPROC object. Note that the PROCLOCK is entered + * into these lists as soon as it is created, even if no lock has yet been + * granted. A PGPROC that is waiting for a lock to be granted will also be + * linked into the lock's waitProcs queue. */ typedef struct PROCLOCKTAG { @@ -239,7 +248,7 @@ extern bool LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag, extern bool LockRelease(LOCKMETHODID lockmethodid, LOCKTAG *locktag, TransactionId xid, LOCKMODE lockmode); extern bool LockReleaseAll(LOCKMETHODID lockmethodid, PGPROC *proc, - bool allxids, TransactionId xid); + LockReleaseWhich which, int nxids, TransactionId *xids); extern int LockCheckConflicts(LockMethod lockMethodTable, LOCKMODE lockmode, LOCK *lock, PROCLOCK *proclock, PGPROC *proc, |