|
8 | 8 | * |
9 | 9 | * |
10 | 10 | * IDENTIFICATION |
11 | | - * $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.145 2004/12/31 22:01:05 pgsql Exp $ |
| 11 | + * $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.146 2005/02/04 02:04:53 neilc Exp $ |
12 | 12 | * |
13 | 13 | * NOTES |
14 | 14 | * Outside modules can create a lock table and acquire/release |
@@ -166,6 +166,8 @@ static int WaitOnLock(LOCKMETHODID lockmethodid, LOCALLOCK *locallock, |
166 | 166 | ResourceOwnerowner); |
167 | 167 | staticvoidLockCountMyLocks(SHMEM_OFFSETlockOffset,PGPROC*proc, |
168 | 168 | int*myHolding); |
| 169 | +staticboolUnGrantLock(LOCK*lock,LOCKMODElockmode, |
| 170 | +PROCLOCK*proclock,LockMethodlockMethodTable); |
169 | 171 |
|
170 | 172 |
|
171 | 173 | /* |
@@ -957,6 +959,65 @@ GrantLock(LOCK *lock, PROCLOCK *proclock, LOCKMODE lockmode) |
957 | 959 | Assert(lock->nGranted <=lock->nRequested); |
958 | 960 | } |
959 | 961 |
|
| 962 | +/* |
| 963 | + * UnGrantLock -- opposite of GrantLock. |
| 964 | + * |
| 965 | + * Updates the lock and proclock data structures to show that the lock |
| 966 | + * is no longer held nor requested by the current holder. |
| 967 | + * |
| 968 | + * Returns true if there were any waiters waiting on the lock that |
| 969 | + * should now be woken up with ProcLockWakeup. |
| 970 | + */ |
| 971 | +staticbool |
| 972 | +UnGrantLock(LOCK*lock,LOCKMODElockmode, |
| 973 | +PROCLOCK*proclock,LockMethodlockMethodTable) |
| 974 | +{ |
| 975 | +boolwakeupNeeded= false; |
| 976 | + |
| 977 | +Assert((lock->nRequested>0)&& (lock->requested[lockmode]>0)); |
| 978 | +Assert((lock->nGranted>0)&& (lock->granted[lockmode]>0)); |
| 979 | +Assert(lock->nGranted <=lock->nRequested); |
| 980 | + |
| 981 | +/* |
| 982 | + * fix the general lock stats |
| 983 | + */ |
| 984 | +lock->nRequested--; |
| 985 | +lock->requested[lockmode]--; |
| 986 | +lock->nGranted--; |
| 987 | +lock->granted[lockmode]--; |
| 988 | + |
| 989 | +if (lock->granted[lockmode]==0) |
| 990 | +{ |
| 991 | +/* change the conflict mask. No more of this lock type. */ |
| 992 | +lock->grantMask &=LOCKBIT_OFF(lockmode); |
| 993 | +} |
| 994 | + |
| 995 | +LOCK_PRINT("UnGrantLock: updated",lock,lockmode); |
| 996 | +Assert((lock->nRequested >=0)&& (lock->requested[lockmode] >=0)); |
| 997 | +Assert((lock->nGranted >=0)&& (lock->granted[lockmode] >=0)); |
| 998 | +Assert(lock->nGranted <=lock->nRequested); |
| 999 | + |
| 1000 | +/* |
| 1001 | + * We need only run ProcLockWakeup if the released lock conflicts with |
| 1002 | + * at least one of the lock types requested by waiter(s). Otherwise |
| 1003 | + * whatever conflict made them wait must still exist. NOTE: before |
| 1004 | + * MVCC, we could skip wakeup if lock->granted[lockmode] was still |
| 1005 | + * positive. But that's not true anymore, because the remaining |
| 1006 | + * granted locks might belong to some waiter, who could now be |
| 1007 | + * awakened because he doesn't conflict with his own locks. |
| 1008 | + */ |
| 1009 | +if (lockMethodTable->conflictTab[lockmode]&lock->waitMask) |
| 1010 | +wakeupNeeded= true; |
| 1011 | + |
| 1012 | +/* |
| 1013 | + * Now fix the per-proclock state. |
| 1014 | + */ |
| 1015 | +proclock->holdMask &=LOCKBIT_OFF(lockmode); |
| 1016 | +PROCLOCK_PRINT("UnGrantLock: updated",proclock); |
| 1017 | + |
| 1018 | +returnwakeupNeeded; |
| 1019 | +} |
| 1020 | + |
960 | 1021 | /* |
961 | 1022 | * GrantLockLocal -- update the locallock data structures to show |
962 | 1023 | *the lock request has been granted. |
@@ -1265,46 +1326,8 @@ LockRelease(LOCKMETHODID lockmethodid, LOCKTAG *locktag, |
1265 | 1326 | RemoveLocalLock(locallock); |
1266 | 1327 | return FALSE; |
1267 | 1328 | } |
1268 | | -Assert((lock->nRequested>0)&& (lock->requested[lockmode]>0)); |
1269 | | -Assert((lock->nGranted>0)&& (lock->granted[lockmode]>0)); |
1270 | | -Assert(lock->nGranted <=lock->nRequested); |
1271 | | - |
1272 | | -/* |
1273 | | - * fix the general lock stats |
1274 | | - */ |
1275 | | -lock->nRequested--; |
1276 | | -lock->requested[lockmode]--; |
1277 | | -lock->nGranted--; |
1278 | | -lock->granted[lockmode]--; |
1279 | | - |
1280 | | -if (lock->granted[lockmode]==0) |
1281 | | -{ |
1282 | | -/* change the conflict mask. No more of this lock type. */ |
1283 | | -lock->grantMask &=LOCKBIT_OFF(lockmode); |
1284 | | -} |
1285 | | - |
1286 | | -LOCK_PRINT("LockRelease: updated",lock,lockmode); |
1287 | | -Assert((lock->nRequested >=0)&& (lock->requested[lockmode] >=0)); |
1288 | | -Assert((lock->nGranted >=0)&& (lock->granted[lockmode] >=0)); |
1289 | | -Assert(lock->nGranted <=lock->nRequested); |
1290 | | - |
1291 | | -/* |
1292 | | - * We need only run ProcLockWakeup if the released lock conflicts with |
1293 | | - * at least one of the lock types requested by waiter(s). Otherwise |
1294 | | - * whatever conflict made them wait must still exist. NOTE: before |
1295 | | - * MVCC, we could skip wakeup if lock->granted[lockmode] was still |
1296 | | - * positive. But that's not true anymore, because the remaining |
1297 | | - * granted locks might belong to some waiter, who could now be |
1298 | | - * awakened because he doesn't conflict with his own locks. |
1299 | | - */ |
1300 | | -if (lockMethodTable->conflictTab[lockmode]&lock->waitMask) |
1301 | | -wakeupNeeded= true; |
1302 | 1329 |
|
1303 | | -/* |
1304 | | - * Now fix the per-proclock state. |
1305 | | - */ |
1306 | | -proclock->holdMask &=LOCKBIT_OFF(lockmode); |
1307 | | -PROCLOCK_PRINT("LockRelease: updated",proclock); |
| 1330 | +wakeupNeeded=UnGrantLock(lock,lockmode,proclock,lockMethodTable); |
1308 | 1331 |
|
1309 | 1332 | /* |
1310 | 1333 | * If this was my last hold on this lock, delete my entry in the |
@@ -1483,22 +1506,8 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allxids) |
1483 | 1506 | for (i=1;i <=numLockModes;i++) |
1484 | 1507 | { |
1485 | 1508 | if (proclock->holdMask&LOCKBIT_ON(i)) |
1486 | | -{ |
1487 | | -lock->requested[i]--; |
1488 | | -lock->granted[i]--; |
1489 | | -Assert(lock->requested[i] >=0&&lock->granted[i] >=0); |
1490 | | -if (lock->granted[i]==0) |
1491 | | -lock->grantMask &=LOCKBIT_OFF(i); |
1492 | | -lock->nRequested--; |
1493 | | -lock->nGranted--; |
1494 | | - |
1495 | | -/* |
1496 | | - * Read comments in LockRelease |
1497 | | - */ |
1498 | | -if (!wakeupNeeded&& |
1499 | | -lockMethodTable->conflictTab[i]&lock->waitMask) |
1500 | | -wakeupNeeded= true; |
1501 | | -} |
| 1509 | +wakeupNeeded |=UnGrantLock(lock,i,proclock, |
| 1510 | +lockMethodTable); |
1502 | 1511 | } |
1503 | 1512 | } |
1504 | 1513 | Assert((lock->nRequested >=0)&& (lock->nGranted >=0)); |
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