/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.undertow.websockets.jsr;
import io.undertow.websockets.core.WebSocketCallback;
import io.undertow.websockets.core.WebSocketChannel;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* Default implementation of a {@link Future} that is used in the {@link javax.websocket.RemoteEndpoint.Async}
* implementation
*
* @author <a href="mailto:nmaurer@redhat.com">Norman Maurer</a>
*/
final class SendResultFuture<T> implements Future<Void>, WebSocketCallback<T> {
private boolean done;
private Throwable exception;
private int waiters;
@Override
public synchronized void complete(WebSocketChannel channel, T context) {
if (done) {
throw new IllegalStateException();
}
if (waiters > 0) {
notifyAll();
}
done = true;
}
@Override
public synchronized void onError(WebSocketChannel channel, T context, Throwable throwable) {
if (done) {
throw new IllegalStateException();
}
exception = throwable;
if (waiters > 0) {
notifyAll();
}
}
/**
* Returns {@code true}
*/
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
return false;
}
@Override
public boolean isCancelled() {
return false;
}
@Override
public synchronized boolean isDone() {
return done;
}
@Override
public Void get() throws InterruptedException, ExecutionException {
if (Thread.interrupted()) {
throw new InterruptedException();
}
synchronized (this) {
while (!done) {
waiters++;
try {
wait();
} finally {
waiters--;
}
}
}
return handleResult();
}
@Override
public Void get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
if (Thread.interrupted()) {
throw new InterruptedException();
}
long timeoutNanos = unit.toNanos(timeout);
long startTime = timeoutNanos <= 0 ? 0 : System.nanoTime();
long waitTime = timeoutNanos;
synchronized (this) {
if (done) {
return handleResult();
}
if (waitTime <= 0) {
throw new TimeoutException();
}
waiters++;
try {
for (; ; ) {
wait(waitTime / 1000000, (int) (waitTime % 1000000));
if (done) {
return handleResult();
} else {
waitTime = timeoutNanos - (System.nanoTime() - startTime);
if (waitTime <= 0) {
if (done) {
return handleResult();
}
if (waitTime <= 0) {
throw new TimeoutException();
}
}
}
}
} finally {
waiters--;
}
}
}
private Void handleResult() throws ExecutionException {
if (exception != null) {
throw new ExecutionException(exception);
}
return null;
}
}