org.jboss.remoting3.util.BlockingInvocation Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2017 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 org.jboss.remoting3.util;
import static org.xnio.IoUtils.safeClose;
import java.io.Closeable;
import java.io.IOException;
import java.util.ArrayDeque;
import org.jboss.remoting3.ChannelClosedException;
import org.jboss.remoting3.MessageInputStream;
/**
* A blocking invocation. This class may be used as-is or subclassed for additional functionality.
*
* @author David M. Lloyd
*/
public class BlockingInvocation extends Invocation {
private final ArrayDeque responses = new ArrayDeque<>(2);
private boolean cancelled;
/**
* Construct a new instance.
*
* @param index the invocation index
*/
public BlockingInvocation(final int index) {
super(index);
}
/**
* Get the next queued response, waiting if necessary. The returned response must be closed.
*
* @return the queued response
* @throws InterruptedException if the thread was interrupted while waiting
*/
public Response getResponse() throws InterruptedException {
final ArrayDeque responses = this.responses;
synchronized (responses) {
if (cancelled) {
throw new IllegalStateException("Waiting on cancelled response");
}
while (responses.isEmpty()) {
responses.wait();
}
return responses.pollFirst();
}
}
public void handleResponse(final int parameter, final MessageInputStream inputStream) {
final ArrayDeque responses = this.responses;
synchronized (responses) {
if (cancelled) {
safeClose(inputStream);
return;
}
responses.add(new Response(inputStream, parameter, null));
responses.notifyAll();
}
}
public void handleClosed() {
final ArrayDeque responses = this.responses;
synchronized (responses) {
responses.add(new Response(null, 0, null));
responses.notifyAll();
}
}
public void handleException(final IOException exception) {
final ArrayDeque responses = this.responses;
synchronized (responses) {
responses.add(new Response(null, 0, exception));
responses.notifyAll();
}
}
/**
* Cancel the invocation, causing all future responses to be closed without being read. This method should only
* be called from the waiting thread (for example, in response to thread interruption).
*/
public void cancel() {
final ArrayDeque responses = this.responses;
synchronized (responses) {
while (! responses.isEmpty()) {
safeClose(responses.poll());
}
cancelled = true;
responses.notifyAll();
}
}
/**
* An invocation response for a blocking invocation.
*/
public final class Response implements Closeable {
private final MessageInputStream inputStream;
private final int parameter;
private final IOException thrown;
Response(final MessageInputStream inputStream, final int parameter, final IOException thrown) {
this.inputStream = inputStream;
this.parameter = parameter;
this.thrown = thrown;
}
/**
* Get the message input stream.
*
* @return the queued input stream
* @throws IOException if the channel was closed, or if another I/O error occurs
*/
public MessageInputStream getInputStream() throws IOException {
if (thrown != null) throw thrown;
final MessageInputStream inputStream = this.inputStream;
if (inputStream == null) {
throw new ChannelClosedException("Channel was closed");
}
return inputStream;
}
/**
* Get the passed-in parameter.
*
* @return the parameter (or 0 if the channel was closed)
*/
public int getParameter() {
return parameter;
}
/**
* Close this response; closes the message stream (if any).
*
* @throws IOException if closing the message stream failed for some reason
*/
public void close() throws IOException {
final MessageInputStream inputStream = this.inputStream;
if (inputStream != null) inputStream.close();
}
}
}