/**
* @return if <0, then this pipe should be stopped. If ==0, it should not wait. If >0, if it
* should wait
*/
int execute() {
if (!lock.tryAcquire()) return 1; // currently being accessed
Thread myThread = Thread.currentThread();
int threadIndex = -1;
for (int i = 0; i < threads.length; i++) {
if (threads[i] == null) {
threads[i] = myThread;
threadIndex = i;
break;
}
if (myThread != threads[i]) continue;
threadIndex = i;
break;
}
Signal signal;
if (threadIndex < 0) {
signal = dummySignal;
} else {
SignalImpl s = signals[threadIndex];
s.threadIndex = threadIndex;
s.signaled = false;
signal = s;
}
boolean hasData;
try {
hasData = poll(signal, null);
} finally {
signal.signal();
if (threadIndex < 0) lock.release();
}
return 0;
}
