/** Same as signalShared, except returns false if queue is empty. */
boolean signalNextShared() {
Node head = mHead;
if (head == null) {
return false;
}
if (head instanceof Shared) {
head.signal();
}
return true;
}
/**
* Signals the first waiter if it is a shared waiter. Exclusive latch must be held, which is still
* held when method returns.
*/
void signalShared() {
Node head = mHead;
if (head instanceof Shared) {
head.signal();
}
}
/**
* Signals the first waiter, unless queue is empty. Exclusive latch must be held, which is still
* held when method returns.
*/
void signal() {
Node head = mHead;
if (head != null) {
head.signal();
}
}
