/**
*
* Copyright 2004 Protique Ltd
*
* 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.activeio.adapter;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.URI;
import org.activeio.AcceptListener;
import org.activeio.AsynchChannelServer;
import org.activeio.Channel;
import org.activeio.ChannelFactory;
import org.activeio.ChannelServer;
import org.activeio.Disposable;
import org.activeio.Service;
import org.activeio.SynchChannelServer;
import EDU.oswego.cs.dl.util.concurrent.Executor;
import EDU.oswego.cs.dl.util.concurrent.Latch;
import EDU.oswego.cs.dl.util.concurrent.SynchronizedBoolean;
/**
* Adapts a {@see org.activeio,SynchChannelServer} so that it provides an
* {@see org.activeio.AsynchChannelServer} interface. When this channel
* is started, a background thread is used to poll the (@see org.activeio.SynchChannelServer}
* for accepted channel connections which are then delivered to the {@see org.activeio.AcceptConsumer}.
*
* @version $Revision$
*/
final public class SynchToAsynchChannelServerAdapter implements AsynchChannelServer, Runnable {
private final SynchChannelServer synchChannelServer;
private final SynchronizedBoolean running = new SynchronizedBoolean(false);
private final Executor executor;
private AcceptListener acceptListener;
private Latch doneLatch;
static public AsynchChannelServer adapt(ChannelServer channel) {
return adapt(channel, ChannelFactory.DEFAULT_EXECUTOR);
}
static public AsynchChannelServer adapt(ChannelServer channel, Executor executor) {
// It might not need adapting
if( channel instanceof AsynchChannelServer ) {
return (AsynchChannelServer) channel;
}
// Can we just just undo the adaptor
if( channel.getClass() == SynchToAsynchChannelAdapter.class ) {
return ((AsynchToSynchChannelServerAdapter)channel).getAsynchChannelServer();
}
return new SynchToAsynchChannelServerAdapter((SynchChannelServer)channel, executor);
}
public SynchToAsynchChannelServerAdapter(SynchChannelServer synchServer) {
this(synchServer, ChannelFactory.DEFAULT_EXECUTOR);
}
public SynchToAsynchChannelServerAdapter(SynchChannelServer synchServer, Executor executor) {
this.synchChannelServer = synchServer;
this.executor=executor;
}
synchronized public void start() throws IOException {
if (running.commit(false, true)) {
if( acceptListener == null )
throw new IllegalStateException("AcceptListener must be set before object can be started.");
synchChannelServer.start();
try {
doneLatch = new Latch();
executor.execute(this);
} catch (InterruptedException e) {
throw new InterruptedIOException(e.getMessage());
}
}
}
synchronized public void stop(long timeout) throws IOException {
if (running.commit(true, false)) {
try {
if( timeout == NO_WAIT_TIMEOUT ) {
synchChannelServer.stop(NO_WAIT_TIMEOUT);
} else if( timeout == WAIT_FOREVER_TIMEOUT ) {
doneLatch.acquire();
synchChannelServer.stop(WAIT_FOREVER_TIMEOUT);
} else {
long start = System.currentTimeMillis();
if( doneLatch.attempt(timeout) ) {
timeout -= (System.currentTimeMillis() - start);
} else {
timeout=0;
}
if( timeout <= 0 ) {
synchChannelServer.stop(NO_WAIT_TIMEOUT);
} else {
synchChannelServer.stop(timeout);
}
}
} catch (IOException e) {
throw e;
} catch (Throwable e) {
throw (IOException)new IOException("stop failed: " + e.getMessage()).initCause(e);
}
}
}
public void run() {
// Change the thread name.
String oldName = Thread.currentThread().getName();
Thread.currentThread().setName( synchChannelServer.toString() );
try {
while (running.get()) {
try {
Channel channel = synchChannelServer.accept(500);
if( channel == null )
continue;
acceptListener.onAccept(channel);
} catch (IOException e) {
if( running.get() )
acceptListener.onAcceptError(e);
} catch (Throwable e) {
if( running.get() )
acceptListener.onAcceptError((IOException)new IOException("Unexpected Error: "+e).initCause(e));
}
}
} finally {
if( doneLatch!=null )
doneLatch.release();
Thread.currentThread().setName(oldName);
}
}
/**
* @see org.activeio.AsynchChannelServer#setAcceptListener(org.activeio.AcceptListener)
*/
public void setAcceptListener(AcceptListener acceptListener) {
if(running.get())
throw new IllegalStateException("Cannot change the AcceptListener while the object is running.");
this.acceptListener = acceptListener;
}
/**
* @see org.activeio.Disposable#dispose()
*/
public void dispose() {
try {
stop(Service.NO_WAIT_TIMEOUT);
} catch ( IOException ignore) {
}
if( synchChannelServer instanceof Disposable ) {
((Disposable)synchChannelServer).dispose();
}
}
public URI getBindURI() {
return synchChannelServer.getBindURI();
}
public URI getConnectURI() {
return synchChannelServer.getConnectURI();
}
public SynchChannelServer getSynchChannelServer() {
return synchChannelServer;
}
public Object narrow(Class target) {
if( target.isAssignableFrom(getClass()) ) {
return this;
}
return synchChannelServer.narrow(target);
}
public String toString() {
return synchChannelServer.toString();
}
}