/**
* block thread until event available
*
* @return available event or null if no event available and return-threshold is reach
* @throws InterruptedException
*/
public EventType waitNewEvent(int waitTimeout) throws InterruptedException {
this.returnCount = 0;
while (true) {
synchronized (this.queue) {
if (Options.LL_DEBUG) {
BtLog.d("EventQueue.waitNewEvent() before remove queue size:" + this.queue.size());
}
// event available => return first event
if (!this.queue.isEmpty()) {
return this.queue.removeFirst();
}
// return threshold is enabled when it's > 0
else if (this.returnThreshold > 0) {
// event not available => check return threshold
// this is for the abnormal case and avoid infinite loop situation (no end event)
this.returnCount++;
if (this.returnCount >= this.returnThreshold) {
return null;
}
}
// wait until event available or timeout
try {
if (this.isCanceled) {
this.isCanceled = false;
return null;
}
this.queue.wait(waitTimeout);
if (this.isCanceled) {
this.isCanceled = false;
return null;
}
} catch (InterruptedException ie) {
BtLog.i(
"EventQueue.waitNewEvent() thread["
+ Thread.currentThread().getName()
+ "] interrupted");
throw ie;
} catch (Exception ex) {
BtLog.e("EventQueue.waitNewEvent() error: " + ex.getMessage());
throw new IllegalStateException("EventQueue.waitNewEvent() error.", ex);
}
}
}
}
/**
* add event into this queue and notify waiting thread to process
*
* @param newEvent
*/
public void notifyNewEvent(EventType newEvent) {
synchronized (this.queue) {
this.queue.addLast(newEvent);
if (Options.LL_DEBUG) {
BtLog.d("EventQueue.notifyNewEvent() after insert queue size:" + this.queue.size());
}
this.queue.notify();
}
}
/** return null from waitNewEvent() */
public void cancelWaitNewEvent() {
synchronized (this.queue) {
this.isCanceled = true;
if (Options.LL_DEBUG) {
BtLog.d("EventQueue.cancelWaitNewEvent():" + this.queue.size());
}
this.queue.notify();
}
}
