| 534 |
534 |
}
|
| 535 |
535 |
|
| 536 |
536 |
private boolean doLock2(Session session, int lockMode, boolean exclusive) {
|
| 537 |
|
if (exclusive) {
|
| 538 |
|
if (lockExclusiveSession == null) {
|
| 539 |
|
if (lockSharedSessions.isEmpty()) {
|
| 540 |
|
traceLock(session, exclusive, "added for");
|
| 541 |
|
session.addLock(this);
|
| 542 |
|
lockExclusiveSession = session;
|
| 543 |
|
return true;
|
| 544 |
|
} else if (lockSharedSessions.size() == 1 &&
|
| 545 |
|
lockSharedSessions.contains(session)) {
|
| 546 |
|
traceLock(session, exclusive, "add (upgraded) for ");
|
| 547 |
|
lockExclusiveSession = session;
|
| 548 |
|
return true;
|
| 549 |
|
}
|
| 550 |
|
}
|
| 551 |
|
} else {
|
| 552 |
|
if (lockExclusiveSession == null) {
|
| 553 |
|
if (lockMode == Constants.LOCK_MODE_READ_COMMITTED) {
|
| 554 |
|
if (!database.isMultiThreaded() && !database.isMultiVersion()) {
|
| 555 |
|
// READ_COMMITTED: a read lock is acquired,
|
| 556 |
|
// but released immediately after the operation
|
| 557 |
|
// is complete.
|
| 558 |
|
// When allowing only one thread, no lock is
|
| 559 |
|
// required.
|
| 560 |
|
// Row level locks work like read committed.
|
|
537 |
synchronized (this) {
|
|
538 |
if (exclusive) {
|
|
539 |
if (lockExclusiveSession == null) {
|
|
540 |
if (lockSharedSessions.isEmpty()) {
|
|
541 |
traceLock(session, exclusive, "added for");
|
|
542 |
session.addLock(this);
|
|
543 |
lockExclusiveSession = session;
|
|
544 |
return true;
|
|
545 |
} else if (lockSharedSessions.size() == 1 &&
|
|
546 |
lockSharedSessions.contains(session)) {
|
|
547 |
traceLock(session, exclusive, "add (upgraded) for ");
|
|
548 |
lockExclusiveSession = session;
|
| 561 |
549 |
return true;
|
| 562 |
550 |
}
|
| 563 |
551 |
}
|
| 564 |
|
if (!lockSharedSessions.contains(session)) {
|
| 565 |
|
traceLock(session, exclusive, "ok");
|
| 566 |
|
session.addLock(this);
|
| 567 |
|
lockSharedSessions.add(session);
|
|
552 |
} else {
|
|
553 |
if (lockExclusiveSession == null) {
|
|
554 |
if (lockMode == Constants.LOCK_MODE_READ_COMMITTED) {
|
|
555 |
if (!database.isMultiThreaded() && !database.isMultiVersion()) {
|
|
556 |
// READ_COMMITTED: a read lock is acquired,
|
|
557 |
// but released immediately after the operation
|
|
558 |
// is complete.
|
|
559 |
// When allowing only one thread, no lock is
|
|
560 |
// required.
|
|
561 |
// Row level locks work like read committed.
|
|
562 |
return true;
|
|
563 |
}
|
|
564 |
}
|
|
565 |
if (!lockSharedSessions.contains(session)) {
|
|
566 |
traceLock(session, exclusive, "ok");
|
|
567 |
session.addLock(this);
|
|
568 |
lockSharedSessions.add(session);
|
|
569 |
}
|
|
570 |
return true;
|
| 568 |
571 |
}
|
| 569 |
|
return true;
|
| 570 |
572 |
}
|
| 571 |
573 |
}
|
| 572 |
574 |
return false;
|
| ... | ... | |
| 639 |
641 |
}
|
| 640 |
642 |
}
|
| 641 |
643 |
}
|
| 642 |
|
if (error == null && lockExclusiveSession != null) {
|
| 643 |
|
Table t = lockExclusiveSession.getWaitForLock();
|
| 644 |
|
if (t != null) {
|
| 645 |
|
error = t.checkDeadlock(lockExclusiveSession, clash, visited);
|
| 646 |
|
if (error != null) {
|
| 647 |
|
error.add(session);
|
|
644 |
synchronized (this)
|
|
645 |
{
|
|
646 |
if (error == null && lockExclusiveSession != null) {
|
|
647 |
Table t = lockExclusiveSession.getWaitForLock();
|
|
648 |
if (t != null) {
|
|
649 |
error = t.checkDeadlock(lockExclusiveSession, clash, visited);
|
|
650 |
if (error != null) {
|
|
651 |
error.add(session);
|
|
652 |
}
|
| 648 |
653 |
}
|
| 649 |
654 |
}
|
| 650 |
655 |
}
|
| ... | ... | |
| 667 |
672 |
@Override
|
| 668 |
673 |
public void unlock(Session s) {
|
| 669 |
674 |
if (database != null) {
|
| 670 |
|
traceLock(s, lockExclusiveSession == s, "unlock");
|
| 671 |
|
if (lockExclusiveSession == s) {
|
| 672 |
|
lockExclusiveSession = null;
|
| 673 |
|
}
|
| 674 |
|
synchronized (database) {
|
|
675 |
synchronized (this) {
|
|
676 |
traceLock(s, lockExclusiveSession == s, "unlock");
|
|
677 |
if (lockExclusiveSession == s) {
|
|
678 |
lockExclusiveSession = null;
|
|
679 |
}
|
| 675 |
680 |
if (!lockSharedSessions.isEmpty()) {
|
| 676 |
681 |
lockSharedSessions.remove(s);
|
| 677 |
682 |
}
|
|
683 |
}
|
|
684 |
synchronized (database) {
|
| 678 |
685 |
if (!waitingSessions.isEmpty()) {
|
| 679 |
686 |
database.notifyAll();
|
| 680 |
687 |
}
|
| ... | ... | |
| 720 |
727 |
scanIndex.remove(session);
|
| 721 |
728 |
database.removeMeta(session, getId());
|
| 722 |
729 |
scanIndex = null;
|
| 723 |
|
lockExclusiveSession = null;
|
|
730 |
synchronized (this)
|
|
731 |
{
|
|
732 |
lockExclusiveSession = null;
|
|
733 |
}
|
| 724 |
734 |
lockSharedSessions = null;
|
| 725 |
735 |
invalidate();
|
| 726 |
736 |
}
|