/**
* Releases this heavy-weight lock on the indicated object.
*
* @param o the object to be unlocked
*/
@Unpreemptible
public void unlockHeavy(Object o) {
boolean deflated = false;
mutex.lock(); // Note: thread switching is not allowed while mutex is held.
RVMThread me = RVMThread.getCurrentThread();
if (ownerId != me.getLockingId()) {
mutex.unlock(); // thread-switching benign
raiseIllegalMonitorStateException("heavy unlocking", o);
}
recursionCount--;
if (0 < recursionCount) {
mutex.unlock(); // thread-switching benign
return;
}
if (STATS) unlockOperations++;
ownerId = 0;
RVMThread toAwaken = entering.dequeue();
if (toAwaken == null && entering.isEmpty() && waiting.isEmpty()) { // heavy lock can be deflated
// Possible project: decide on a heuristic to control when lock should be deflated
Offset lockOffset = Magic.getObjectType(o).getThinLockOffset();
if (!lockOffset.isMax()) { // deflate heavy lock
deflate(o, lockOffset);
deflated = true;
}
}
mutex.unlock(); // does a Magic.sync(); (thread-switching benign)
if (toAwaken != null) {
toAwaken.monitor().lockedBroadcastNoHandshake();
}
}
