@Override
public boolean commit() {
try {
if (!writeSet.isEmpty()) {
int v = status.get();
int s = v & STATUS_MASK;
if (s == TX_ACTIVE && status.compareAndSet(v, v + (TX_COMMITTING - TX_ACTIVE))) {
long newClock = clock.incrementAndGet();
if (newClock != startTime.get() + 1 && !readSet.validate(this, id)) {
rollback0();
return false;
}
// Write values and release locks
writeSet.commit(newClock);
status.set(v + (TX_COMMITTED - TX_ACTIVE));
} else {
// We have been killed: wait for our locks to have been released
while (s != TX_ABORTED) s = status.get() & STATUS_MASK;
return false;
}
} else {
// No need to set status to COMMITTED (we cannot be killed with an empty write set)
}
attempts = 0;
return true;
} finally {
if (irrevocableState) {
irrevocableState = false;
irrevocableAccessLock.writeLock().unlock();
} else {
irrevocableAccessLock.readLock().unlock();
}
}
}
private boolean extend() {
long now = clock.get();
if (readSet.validate(this, id)) {
endTime = now;
return true;
}
return false;
}