org.asynchttpclient.shaded.netty.channel.MaxConnectionSemaphore Maven / Gradle / Ivy
/*
* Copyright (c) 2018 AsyncHttpClient Project. All rights reserved.
*
* This program is licensed to you under the Apache License Version 2.0,
* and you may not use this file except in compliance with the Apache License Version 2.0.
* You may obtain a copy of the Apache License Version 2.0 at
* http://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the Apache License Version 2.0 is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
*/
package org.asynchttpclient.shaded.netty.channel;
import org.asynchttpclient.shaded.exception.TooManyConnectionsException;
import java.io.IOException;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import static org.asynchttpclient.shaded.util.ThrowableUtil.unknownStackTrace;
/**
* Max connections limiter.
*
* @author Stepan Koltsov
* @author Alex Maltinsky
*/
public class MaxConnectionSemaphore implements ConnectionSemaphore {
protected final Semaphore freeChannels;
protected final IOException tooManyConnections;
protected final int acquireTimeout;
MaxConnectionSemaphore(int maxConnections, int acquireTimeout) {
tooManyConnections = unknownStackTrace(new TooManyConnectionsException(maxConnections), MaxConnectionSemaphore.class, "acquireChannelLock");
freeChannels = maxConnections > 0 ? new Semaphore(maxConnections) : InfiniteSemaphore.INSTANCE;
this.acquireTimeout = Math.max(0, acquireTimeout);
}
@Override
public void acquireChannelLock(Object partitionKey) throws IOException {
try {
if (!freeChannels.tryAcquire(acquireTimeout, TimeUnit.MILLISECONDS)) {
throw tooManyConnections;
}
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
@Override
public void releaseChannelLock(Object partitionKey) {
freeChannels.release();
}
}