static void close(OioDatagramChannel channel, ChannelFuture future) {
boolean connected = channel.isConnected();
boolean bound = channel.isBound();
try {
channel.socket.close();
if (channel.setClosed()) {
future.setSuccess();
if (connected) {
// Notify the worker so it stops reading.
Thread currentThread = Thread.currentThread();
Thread workerThread = channel.workerThread;
if (workerThread != null && currentThread != workerThread) {
workerThread.interrupt();
}
fireChannelDisconnected(channel);
}
if (bound) {
fireChannelUnbound(channel);
}
fireChannelClosed(channel);
} else {
future.setSuccess();
}
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
private void connect(
OioDatagramChannel channel, ChannelFuture future, SocketAddress remoteAddress) {
boolean bound = channel.isBound();
boolean connected = false;
boolean workerStarted = false;
future.addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
// Clear the cached address so that the next getRemoteAddress() call
// updates the cache.
channel.remoteAddress = null;
try {
channel.socket.connect(remoteAddress);
connected = true;
// Fire events.
future.setSuccess();
if (!bound) {
fireChannelBound(channel, channel.getLocalAddress());
}
fireChannelConnected(channel, channel.getRemoteAddress());
String threadName =
"Old I/O datagram worker (channelId: "
+ channel.getId()
+ ", "
+ channel.getLocalAddress()
+ " => "
+ channel.getRemoteAddress()
+ ')';
if (!bound) {
// Start the business.
workerExecutor.execute(
new IoWorkerRunnable(
new ThreadRenamingRunnable(new OioDatagramWorker(channel), threadName)));
} else {
// Worker started by bind() - just rename.
Thread workerThread = channel.workerThread;
if (workerThread != null) {
try {
workerThread.setName(threadName);
} catch (SecurityException e) {
// Ignore.
}
}
}
workerStarted = true;
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
} finally {
if (connected && !workerStarted) {
OioDatagramWorker.close(channel, future);
}
}
}
@Override
protected boolean scheduleWriteIfNecessary(final AbstractNioChannel<?> channel) {
final Thread currentThread = Thread.currentThread();
final Thread workerThread = thread;
if (currentThread != workerThread) {
if (channel.writeTaskInTaskQueue.compareAndSet(false, true)) {
boolean offered = writeTaskQueue.offer(channel.writeTask);
assert offered;
}
if (!(channel instanceof NioAcceptedSocketChannel)
|| ((NioAcceptedSocketChannel) channel).bossThread != currentThread) {
final Selector workerSelector = selector;
if (workerSelector != null) {
if (wakenUp.compareAndSet(false, true)) {
workerSelector.wakeup();
}
}
} else {
// A write request can be made from an acceptor thread (boss)
// when a user attempted to write something in:
//
// * channelOpen()
// * channelBound()
// * channelConnected().
//
// In this case, there's no need to wake up the selector because
// the channel is not even registered yet at this moment.
}
return true;
}
return false;
}
static void setInterestOps(OioDatagramChannel channel, ChannelFuture future, int interestOps) {
// Override OP_WRITE flag - a user cannot change this flag.
interestOps &= ~Channel.OP_WRITE;
interestOps |= channel.getInterestOps() & Channel.OP_WRITE;
boolean changed = false;
try {
if (channel.getInterestOps() != interestOps) {
if ((interestOps & Channel.OP_READ) != 0) {
channel.setInterestOpsNow(Channel.OP_READ);
} else {
channel.setInterestOpsNow(Channel.OP_NONE);
}
changed = true;
}
future.setSuccess();
if (changed) {
synchronized (channel.interestOpsLock) {
channel.setInterestOpsNow(interestOps);
// Notify the worker so it stops or continues reading.
Thread currentThread = Thread.currentThread();
Thread workerThread = channel.workerThread;
if (workerThread != null && currentThread != workerThread) {
workerThread.interrupt();
}
}
fireChannelInterestChanged(channel);
}
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
public void run() {
channel.workerThread = Thread.currentThread();
final MulticastSocket socket = channel.socket;
while (channel.isOpen()) {
synchronized (channel.interestOpsLock) {
while (!channel.isReadable()) {
try {
// notify() is not called at all.
// close() and setInterestOps() calls Thread.interrupt()
channel.interestOpsLock.wait();
} catch (InterruptedException e) {
if (!channel.isOpen()) {
break;
}
}
}
}
ReceiveBufferSizePredictor predictor = channel.getConfig().getReceiveBufferSizePredictor();
byte[] buf = new byte[predictor.nextReceiveBufferSize()];
DatagramPacket packet = new DatagramPacket(buf, buf.length);
try {
socket.receive(packet);
} catch (InterruptedIOException e) {
// Can happen on interruption.
// Keep receiving unless the channel is closed.
continue;
} catch (Throwable t) {
if (!channel.socket.isClosed()) {
fireExceptionCaught(channel, t);
}
break;
}
fireMessageReceived(
channel,
channel.getConfig().getBufferFactory().getBuffer(buf, 0, packet.getLength()),
packet.getSocketAddress());
}
// Setting the workerThread to null will prevent any channel
// operations from interrupting this thread from now on.
channel.workerThread = null;
// Clean up.
close(channel, succeededFuture(channel));
}
static void disconnect(OioDatagramChannel channel, ChannelFuture future) {
boolean connected = channel.isConnected();
try {
channel.socket.disconnect();
future.setSuccess();
if (connected) {
// Update the worker's thread name to reflect the state change.
Thread workerThread = channel.workerThread;
if (workerThread != null) {
try {
workerThread.setName("Old I/O datagram worker (" + channel + ')');
} catch (SecurityException e) {
// Ignore.
}
}
// Notify.
fireChannelDisconnected(channel);
}
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
private ChannelBuffer unwrap(
ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer, int offset, int length)
throws SSLException {
ByteBuffer inNetBuf = buffer.toByteBuffer(offset, length);
ByteBuffer outAppBuf = bufferPool.acquire();
try {
boolean needsWrap = false;
loop:
for (; ; ) {
SSLEngineResult result;
synchronized (handshakeLock) {
if (!handshaken
&& !handshaking
&& !engine.getUseClientMode()
&& !engine.isInboundDone()
&& !engine.isOutboundDone()) {
handshake();
}
try {
result = engine.unwrap(inNetBuf, outAppBuf);
} catch (SSLException e) {
throw e;
}
final HandshakeStatus handshakeStatus = result.getHandshakeStatus();
handleRenegotiation(handshakeStatus);
switch (handshakeStatus) {
case NEED_UNWRAP:
if (inNetBuf.hasRemaining() && !engine.isInboundDone()) {
break;
} else {
break loop;
}
case NEED_WRAP:
wrapNonAppData(ctx, channel);
break;
case NEED_TASK:
runDelegatedTasks();
break;
case FINISHED:
setHandshakeSuccess(channel);
needsWrap = true;
break loop;
case NOT_HANDSHAKING:
needsWrap = true;
break loop;
default:
throw new IllegalStateException("Unknown handshake status: " + handshakeStatus);
}
}
}
if (needsWrap) {
// wrap() acquires pendingUnencryptedWrites first and then
// handshakeLock. If handshakeLock is already hold by the
// current thread, calling wrap() will lead to a dead lock
// i.e. pendingUnencryptedWrites -> handshakeLock vs.
// handshakeLock -> pendingUnencryptedLock -> handshakeLock
//
// There is also a same issue between pendingEncryptedWrites
// and pendingUnencryptedWrites.
if (!Thread.holdsLock(handshakeLock)
&& !pendingEncryptedWritesLock.isHeldByCurrentThread()) {
wrap(ctx, channel);
}
}
outAppBuf.flip();
if (outAppBuf.hasRemaining()) {
ChannelBuffer frame = ChannelBuffers.buffer(outAppBuf.remaining());
frame.writeBytes(outAppBuf.array(), 0, frame.capacity());
return frame;
} else {
return null;
}
} catch (SSLException e) {
setHandshakeFailure(channel, e);
throw e;
} finally {
bufferPool.release(outAppBuf);
}
}
private ChannelFuture wrapNonAppData(ChannelHandlerContext ctx, Channel channel)
throws SSLException {
ChannelFuture future = null;
ByteBuffer outNetBuf = bufferPool.acquire();
SSLEngineResult result;
try {
for (; ; ) {
synchronized (handshakeLock) {
result = engine.wrap(EMPTY_BUFFER, outNetBuf);
}
if (result.bytesProduced() > 0) {
outNetBuf.flip();
ChannelBuffer msg = ChannelBuffers.buffer(outNetBuf.remaining());
msg.writeBytes(outNetBuf.array(), 0, msg.capacity());
outNetBuf.clear();
future = future(channel);
future.addListener(
new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) throws Exception {
if (future.getCause() instanceof ClosedChannelException) {
synchronized (ignoreClosedChannelExceptionLock) {
ignoreClosedChannelException++;
}
}
}
});
write(ctx, future, msg);
}
final HandshakeStatus handshakeStatus = result.getHandshakeStatus();
handleRenegotiation(handshakeStatus);
switch (handshakeStatus) {
case FINISHED:
setHandshakeSuccess(channel);
runDelegatedTasks();
break;
case NEED_TASK:
runDelegatedTasks();
break;
case NEED_UNWRAP:
if (!Thread.holdsLock(handshakeLock)) {
// unwrap shouldn't be called when this method was
// called by unwrap - unwrap will keep running after
// this method returns.
unwrap(ctx, channel, ChannelBuffers.EMPTY_BUFFER, 0, 0);
}
break;
case NOT_HANDSHAKING:
case NEED_WRAP:
break;
default:
throw new IllegalStateException("Unexpected handshake status: " + handshakeStatus);
}
if (result.bytesProduced() == 0) {
break;
}
}
} catch (SSLException e) {
setHandshakeFailure(channel, e);
throw e;
} finally {
bufferPool.release(outNetBuf);
}
if (future == null) {
future = succeededFuture(channel);
}
return future;
}
static void setInterestOps(NioSocketChannel channel, ChannelFuture future, int interestOps) {
boolean changed = false;
try {
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
NioWorker worker = channel.worker;
Selector selector = worker.selector;
SelectionKey key = channel.socket.keyFor(selector);
if (key == null || selector == null) {
// Not registered to the worker yet.
// Set the rawInterestOps immediately; RegisterTask will pick it up.
channel.setRawInterestOpsNow(interestOps);
return;
}
// Override OP_WRITE flag - a user cannot change this flag.
interestOps &= ~Channel.OP_WRITE;
interestOps |= channel.getRawInterestOps() & Channel.OP_WRITE;
switch (CONSTRAINT_LEVEL) {
case 0:
if (channel.getRawInterestOps() != interestOps) {
key.interestOps(interestOps);
if (Thread.currentThread() != worker.thread
&& worker.wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
changed = true;
}
break;
case 1:
case 2:
if (channel.getRawInterestOps() != interestOps) {
if (Thread.currentThread() == worker.thread) {
key.interestOps(interestOps);
changed = true;
} else {
worker.selectorGuard.readLock().lock();
try {
if (worker.wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
key.interestOps(interestOps);
changed = true;
} finally {
worker.selectorGuard.readLock().unlock();
}
}
}
break;
default:
throw new Error();
}
}
future.setSuccess();
if (changed) {
channel.setRawInterestOpsNow(interestOps);
fireChannelInterestChanged(channel);
}
} catch (CancelledKeyException e) {
// setInterestOps() was called on a closed channel.
ClosedChannelException cce = new ClosedChannelException();
future.setFailure(cce);
fireExceptionCaught(channel, cce);
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
public void run() {
thread = Thread.currentThread();
boolean shutdown = false;
Selector selector = this.selector;
for (; ; ) {
wakenUp.set(false);
if (CONSTRAINT_LEVEL != 0) {
selectorGuard.writeLock().lock();
// This empty synchronization block prevents the selector
// from acquiring its lock.
selectorGuard.writeLock().unlock();
}
try {
selector.select(500);
// 'wakenUp.compareAndSet(false, true)' is always evaluated
// before calling 'selector.wakeup()' to reduce the wake-up
// overhead. (Selector.wakeup() is an expensive operation.)
//
// However, there is a race condition in this approach.
// The race condition is triggered when 'wakenUp' is set to
// true too early.
//
// 'wakenUp' is set to true too early if:
// 1) Selector is waken up between 'wakenUp.set(false)' and
// 'selector.select(...)'. (BAD)
// 2) Selector is waken up between 'selector.select(...)' and
// 'if (wakenUp.get()) { ... }'. (OK)
//
// In the first case, 'wakenUp' is set to true and the
// following 'selector.select(...)' will wake up immediately.
// Until 'wakenUp' is set to false again in the next round,
// 'wakenUp.compareAndSet(false, true)' will fail, and therefore
// any attempt to wake up the Selector will fail, too, causing
// the following 'selector.select(...)' call to block
// unnecessarily.
//
// To fix this problem, we wake up the selector again if wakenUp
// is true immediately after selector.select(...).
// It is inefficient in that it wakes up the selector for both
// the first case (BAD - wake-up required) and the second case
// (OK - no wake-up required).
if (wakenUp.get()) {
selector.wakeup();
}
cancelledKeys = 0;
processRegisterTaskQueue();
processWriteTaskQueue();
processSelectedKeys(selector.selectedKeys());
// Exit the loop when there's nothing to handle.
// The shutdown flag is used to delay the shutdown of this
// loop to avoid excessive Selector creation when
// connections are registered in a one-by-one manner instead of
// concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown
|| executor instanceof ExecutorService && ((ExecutorService) executor).isShutdown()) {
synchronized (startStopLock) {
if (registerTaskQueue.isEmpty() && selector.keys().isEmpty()) {
started = false;
try {
selector.close();
} catch (IOException e) {
logger.warn("Failed to close a selector.", e);
} finally {
this.selector = null;
}
break;
} else {
shutdown = false;
}
}
} else {
// Give one more second.
shutdown = true;
}
} else {
shutdown = false;
}
} catch (Throwable t) {
logger.warn("Unexpected exception in the selector loop.", t);
// Prevent possible consecutive immediate failures that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}