/**
* @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;
}
/**
* Look for data from all the inputs
*
* @return true if data was consumed
*/
private boolean poll(Signal signal, Signal parent) {
AtomicReferenceArray<T> o = outputs;
for (int i = 0; i < o.length(); i++) {
T input = o.getAndSet(i, null);
if (input == null) continue;
long seq = ++sequence;
if (parent != null) parent.signal();
S product = producer.execute(input, reuseReceptors.get(i), signal);
signal.signal();
if (!consume(product, seq, 0)) {
Thread.yield();
if (!consume(product, seq, 0))
logger.info(
"failed to consume product (" + product + ") from producer (" + producer + ")");
}
producer.complete(product);
return product != null;
}
return false;
}
@Override
public Boolean execute(Object d, Receptor<Object> r, Signal parent) {
r.lazySet(d); // put the data back in for polling
boolean data = false;
for (int i = 0; i < children.length; i++) {
AtomicIntegerArray inUse = this.inUse;
if (!inUse.compareAndSet(i, 0, 1)) {
if (inUse.get(i) == 2) sleep();
continue;
}
PooledFatPipe child = children[i];
if (child == null) {
inUse.set(i, 0);
continue;
}
Signal signal;
if (parent.getThreadIndex() < 0) {
signal = new ChildSignalImpl(inUse, i);
} else {
ChildSignalImpl s = signals[i * poolSize + parent.getThreadIndex()];
if (s == null || s.inUse != inUse) {
sleep();
inUse.set(i, 0);
continue;
}
s.index = i;
s.notified = false;
signal = s;
}
try {
data |= child.poll(signal, parent);
} catch (Exception e) {
if (listener == null) logger.error("poll", e);
else listener.exceptionThrown(e);
} finally {
signal.signal();
}
}
return data ? Boolean.TRUE : null;
}