/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.mina.transport.socket.nio;
import java.io.IOException;
import java.nio.channels.ByteChannel;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.Executor;
import org.apache.mina.core.RuntimeIoException;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.file.FileRegion;
import org.apache.mina.core.polling.AbstractPollingIoProcessor;
import org.apache.mina.core.session.SessionState;
/**
* TODO Add documentation
*
* @author <a href="http://mina.apache.org">Apache MINA Project</a>
*/
public final class NioProcessor extends AbstractPollingIoProcessor<NioSession> {
/** The selector associated with this processor */
private Selector selector;
/**
*
* Creates a new instance of NioProcessor.
*
* @param executor
*/
public NioProcessor(Executor executor) {
super(executor);
try {
// Open a new selector
selector = Selector.open();
} catch (IOException e) {
throw new RuntimeIoException("Failed to open a selector.", e);
}
}
@Override
protected void doDispose() throws Exception {
selector.close();
}
@Override
protected int select(long timeout) throws Exception {
return selector.select(timeout);
}
@Override
protected int select() throws Exception {
return selector.select();
}
@Override
protected boolean isSelectorEmpty() {
return selector.keys().isEmpty();
}
@Override
protected void wakeup() {
wakeupCalled.getAndSet(true);
selector.wakeup();
}
@Override
protected Iterator<NioSession> allSessions() {
return new IoSessionIterator(selector.keys());
}
@SuppressWarnings("synthetic-access")
@Override
protected Iterator<NioSession> selectedSessions() {
return new IoSessionIterator(selector.selectedKeys());
}
@Override
protected void init(NioSession session) throws Exception {
SelectableChannel ch = (SelectableChannel) session.getChannel();
ch.configureBlocking(false);
session.setSelectionKey(ch.register(selector, SelectionKey.OP_READ,
session));
}
@Override
protected void destroy(NioSession session) throws Exception {
ByteChannel ch = session.getChannel();
SelectionKey key = session.getSelectionKey();
if (key != null) {
key.cancel();
}
ch.close();
}
/**
* In the case we are using the java select() method, this method is used to
* trash the buggy selector and create a new one, registering all the
* sockets on it.
*/
@Override
protected void registerNewSelector() throws IOException {
synchronized (selector) {
Set<SelectionKey> keys = selector.keys();
// Open a new selector
Selector newSelector = Selector.open();
// Loop on all the registered keys, and register them on the new selector
for (SelectionKey key : keys) {
SelectableChannel ch = key.channel();
// Don't forget to attache the session, and back !
NioSession session = (NioSession)key.attachment();
SelectionKey newKey = ch.register(newSelector, key.interestOps(), session);
session.setSelectionKey( newKey );
}
// Now we can close the old selector and switch it
selector.close();
selector = newSelector;
}
}
/**
* {@inheritDoc}
*/
@Override
protected boolean isBrokenConnection() throws IOException {
// A flag set to true if we find a broken session
boolean brokenSession = false;
synchronized (selector) {
// Get the selector keys
Set<SelectionKey> keys = selector.keys();
// Loop on all the keys to see if one of them
// has a closed channel
for (SelectionKey key : keys) {
SelectableChannel channel = key.channel();
if ((((channel instanceof DatagramChannel) && !((DatagramChannel) channel)
.isConnected()))
|| ((channel instanceof SocketChannel) && !((SocketChannel) channel)
.isConnected())) {
// The channel is not connected anymore. Cancel
// the associated key then.
key.cancel();
// Set the flag to true to avoid a selector switch
brokenSession = true;
}
}
}
return brokenSession;
}
/**
* {@inheritDoc}
*/
@Override
protected SessionState getState(NioSession session) {
SelectionKey key = session.getSelectionKey();
if (key == null) {
// The channel is not yet registred to a selector
return SessionState.OPENING;
}
if (key.isValid()) {
// The session is opened
return SessionState.OPENED;
} else {
// The session still as to be closed
return SessionState.CLOSING;
}
}
@Override
protected boolean isReadable(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && key.isReadable();
}
@Override
protected boolean isWritable(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && key.isWritable();
}
@Override
protected boolean isInterestedInRead(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && ( (key.interestOps() & SelectionKey.OP_READ) != 0 );
}
@Override
protected boolean isInterestedInWrite(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid()
&& ( (key.interestOps() & SelectionKey.OP_WRITE) != 0 );
}
/**
* {@inheritDoc}
*/
@Override
protected void setInterestedInRead(NioSession session, boolean isInterested)
throws Exception {
SelectionKey key = session.getSelectionKey();
int oldInterestOps = key.interestOps();
int newInterestOps = oldInterestOps;
if (isInterested) {
newInterestOps |= SelectionKey.OP_READ;
} else {
newInterestOps &= ~SelectionKey.OP_READ;
}
if (oldInterestOps != newInterestOps) {
key.interestOps(newInterestOps);
}
}
/**
* {@inheritDoc}
*/
@Override
protected void setInterestedInWrite(NioSession session, boolean isInterested)
throws Exception {
SelectionKey key = session.getSelectionKey();
if (key == null) {
return;
}
int newInterestOps = key.interestOps();
if (isInterested) {
newInterestOps |= SelectionKey.OP_WRITE;
//newInterestOps &= ~SelectionKey.OP_READ;
} else {
newInterestOps &= ~SelectionKey.OP_WRITE;
//newInterestOps |= SelectionKey.OP_READ;
}
key.interestOps(newInterestOps);
}
@Override
protected int read(NioSession session, IoBuffer buf) throws Exception {
ByteChannel channel = session.getChannel();
return channel.read(buf.buf());
}
@Override
protected int write(NioSession session, IoBuffer buf, int length)
throws Exception {
if (buf.remaining() <= length) {
return session.getChannel().write(buf.buf());
}
int oldLimit = buf.limit();
buf.limit(buf.position() + length);
try {
return session.getChannel().write(buf.buf());
} finally {
buf.limit(oldLimit);
}
}
@Override
protected int transferFile(NioSession session, FileRegion region, int length)
throws Exception {
try {
return (int) region.getFileChannel().transferTo(
region.getPosition(), length, session.getChannel());
} catch (IOException e) {
// Check to see if the IOException is being thrown due to
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5103988
String message = e.getMessage();
if (( message != null ) && message.contains("temporarily unavailable")) {
return 0;
}
throw e;
}
}
/**
* An encapsulating iterator around the {@link Selector#selectedKeys()} or
* the {@link Selector#keys()} iterator;
*/
protected static class IoSessionIterator<NioSession> implements
Iterator<NioSession> {
private final Iterator<SelectionKey> iterator;
/**
* Create this iterator as a wrapper on top of the selectionKey Set.
*
* @param keys
* The set of selected sessions
*/
private IoSessionIterator(Set<SelectionKey> keys) {
iterator = keys.iterator();
}
/**
* {@inheritDoc}
*/
public boolean hasNext() {
return iterator.hasNext();
}
/**
* {@inheritDoc}
*/
public NioSession next() {
SelectionKey key = iterator.next();
NioSession nioSession = (NioSession) key.attachment();
return nioSession;
}
/**
* {@inheritDoc}
*/
public void remove() {
iterator.remove();
}
}
}