Java Code Examples for java.nio.channels.Selector#wakeup()

public static void main(String argv[]) throws Exception {
    int waitTime = 4000;
    Selector selector = Selector.open();
    try {
        selector.wakeup();

        long t1 = System.currentTimeMillis();
        selector.select(waitTime);
        long t2 = System.currentTimeMillis();
        long totalTime = t2 - t1;

        if (totalTime > waitTime)
            throw new RuntimeException("Test failed");
    } finally {
        selector.close();
    }
}
 

void reply(XulHttpServerResponse serverResponse) {
	_response = serverResponse;

	serverResponse.addHeaderIfNotExists("Content-Type", "text/html")
		.addHeaderIfNotExists("Connection", "close");

	final String transferEncoding = _response.headers.get("Transfer-Encoding");
	_sendChunkedData = "chunked".equals(transferEncoding);
	serverResponse.prepareResponseData();

	_responseBuffer = ByteBuffer.wrap(serverResponse.getData(), 0, serverResponse.getDataSize());
	try {
		Selector selector = _server._selector;
		_socketChannel.register(selector, SelectionKey.OP_WRITE, this);
		selector.wakeup();
	} catch (ClosedChannelException e) {
		clear();
		XulLog.e(TAG, e);
	}
}
 

public static void main(String argv[]) throws Exception {
    int waitTime = 4000;
    Selector selector = Selector.open();
    try {
        selector.wakeup();

        long t1 = System.currentTimeMillis();
        selector.select(waitTime);
        long t2 = System.currentTimeMillis();
        long totalTime = t2 - t1;

        if (totalTime > waitTime)
            throw new RuntimeException("Test failed");
    } finally {
        selector.close();
    }
}
 

/**
 * Close Selector.
 *
 * @see org.apache.catalina.tribes.transport.ReceiverBase#stop()
 */
protected void stopListening() {
    setListen(false);
    Selector selector = this.selector.get();
    if (selector != null) {
        try {
            // Unlock the thread if is is blocked waiting for input
            selector.wakeup();
            // Wait for the receiver thread to finish
            int count = 0;
            while (running && count < 50) {
                Thread.sleep(100);
                count ++;
            }
            if (running) {
                log.warn(sm.getString("NioReceiver.stop.threadRunning"));
            }
            closeSelector();
        } catch (Exception x) {
            log.error("Unable to close cluster receiver selector.", x);
        } finally {
            this.selector.set(null);
        }
    }
}
 

public static void main(String argv[]) throws Exception {
    int waitTime = 4000;
    Selector selector = Selector.open();
    try {
        selector.wakeup();

        long t1 = System.currentTimeMillis();
        selector.select(waitTime);
        long t2 = System.currentTimeMillis();
        long totalTime = t2 - t1;

        if (totalTime > waitTime)
            throw new RuntimeException("Test failed");
    } finally {
        selector.close();
    }
}
 

@Test
void cancelledKeyRemovedFromChannel() throws Exception {
  Pipe pipe = Pipe.open();

  Selector selector = Selector.open();
  SelectableChannel source = pipe.source();
  source.configureBlocking(false);

  for (int i = 0; i < 1000; ++i) {
    assertNull(source.keyFor(selector));

    SelectionKey key = source.register(selector, OP_READ);

    selector.selectedKeys().clear();
    selector.selectNow();

    key.cancel();
    selector.wakeup();

    selector.selectedKeys().clear();
    selector.selectNow();
  }
}
 

protected final void registerTask(Runnable task) {
	taskQueue.add(task);

	Selector selector = this.selector;

	if (selector != null) {
		if (wakenUp.compareAndSet(false, true)) {
			selector.wakeup();
		}
	} else {
		if (taskQueue.remove(task)) {
			// the selector was null this means the Worker has already been
			// shutdown.
			throw new RejectedExecutionException("Worker has already been shutdown");
		}
	}
}
 

public void wakeup()
{
    try
    {
        Selector selector = _selector;
        if (selector!=null)
            selector.wakeup();
    }
    catch(Exception e)
    {
        addChange(new ChangeTask()
        {
            public void run()
            {
                renewSelector();
            }
        });

        renewSelector();
    }
}
 

public static void main(String argv[]) throws Exception {
    int waitTime = 4000;
    Selector selector = Selector.open();
    try {
        selector.wakeup();

        long t1 = System.currentTimeMillis();
        selector.select(waitTime);
        long t2 = System.currentTimeMillis();
        long totalTime = t2 - t1;

        if (totalTime > waitTime)
            throw new RuntimeException("Test failed");
    } finally {
        selector.close();
    }
}
 

@Test
void cancelledKeyRemovedFromChannel() throws Exception {
  Pipe pipe = Pipe.open();

  Selector selector = Selector.open();
  SelectableChannel source = pipe.source();
  source.configureBlocking(false);

  for (int i = 0; i < 1000; ++i) {
    assertNull(source.keyFor(selector));

    SelectionKey key = source.register(selector, OP_READ);

    selector.selectedKeys().clear();
    selector.selectNow();

    key.cancel();
    selector.wakeup();

    selector.selectedKeys().clear();
    selector.selectNow();
  }
}
 

public static void main(String[] args) throws Exception {
    final Selector sel = Selector.open();

    Runnable r = new Runnable() {
        public void run() {
            try {
                sel.select();
            } catch (IOException x) {
                x.printStackTrace();
            }
        }
    };

    // start thread to block in Selector
    Thread t = new Thread(r);
    t.start();

    // give thread time to start
    Thread.sleep(1000);

    // interrupt, close, and wakeup is the magic sequence to provoke the NPE
    t.interrupt();
    sel.close();
    sel.wakeup();
}
 

/**
 * Close Selector.
 *
 * @see org.apache.catalina.tribes.transport.ReceiverBase#stop()
 */
protected void stopListening() {
    setListen(false);
    Selector selector = this.selector.get();
    if (selector != null) {
        try {
            // Unlock the thread if is is blocked waiting for input
            selector.wakeup();
            // Wait for the receiver thread to finish
            int count = 0;
            while (running && count < 50) {
                Thread.sleep(100);
                count ++;
            }
            if (running) {
                log.warn(sm.getString("NioReceiver.stop.threadRunning"));
            }
            closeSelector();
        } catch (Exception x) {
            log.error("Unable to close cluster receiver selector.", x);
        } finally {
            this.selector.set(null);
        }
    }
}
 

public void addEvent(Runnable event) {
    Selector selector = this.selector.get();
    if ( selector != null ) {
        synchronized (events) {
            events.add(event);
        }
        if ( log.isTraceEnabled() ) log.trace("Adding event to selector:"+event);
        if ( isListening() ) selector.wakeup();
    }
}
 

@Test
void selectorRemovesKeysOnChannelCloseWhileSelecting() throws Exception {
  Pipe pipe = Pipe.open();

  Selector selector = Selector.open();
  SelectableChannel source = pipe.source();
  source.configureBlocking(false);

  SelectionKey key = source.register(selector, OP_READ);
  assertTrue(selector.keys().contains(key));

  CountDownLatch latch = new CountDownLatch(1);
  Future<?> job = executor.submit(() -> {
    latch.countDown();
    try {
      selector.select();
    } catch (IOException e) {
      throw new UncheckedIOException(e);
    }
  });

  latch.await();
  Thread.sleep(100);

  source.close();
  selector.wakeup();
  job.get();
  assertFalse(selector.keys().contains(key));
}
 

@Test
void selectorRemovesKeysOnCancelWhileSelecting() throws Exception {
  Pipe pipe = Pipe.open();

  Selector selector = Selector.open();
  SelectableChannel source = pipe.source();
  source.configureBlocking(false);

  SelectionKey key = source.register(selector, OP_READ);
  assertTrue(selector.keys().contains(key));

  CountDownLatch latch = new CountDownLatch(1);
  Future<?> job = executor.submit(() -> {
    latch.countDown();
    try {
      selector.select();
    } catch (IOException e) {
      throw new UncheckedIOException(e);
    }
  });

  latch.await();
  Thread.sleep(100);

  key.cancel();
  assertTrue(selector.keys().contains(key));
  assertSame(key, source.keyFor(selector));

  selector.wakeup();
  job.get();
  assertFalse(selector.keys().contains(key));
  assertNull(source.keyFor(selector));
}
 

@Override
public synchronized void shutdown()
{
    shutdownFlag.set(true);
    Selector srvSel = serverSelector;
    if (srvSel != null)
    {
        srvSel.wakeup();
    }
}
 

public void run(Timeout timeout) throws Exception {
    // This is needed to prevent a possible race that can lead to a NPE
    // when the selector is closed before this is run
    //
    // See https://github.com/netty/netty/issues/685
    Selector selector = NioClientBoss.this.selector;

    if (selector != null) {
        if (wakenUp.compareAndSet(false, true)) {
            selector.wakeup();
        }
    }
}
 

void notifyWritable() throws IOException {
	if (_responseBuffer == null) {
		return;
	}

	final SocketChannel socketChannel = _socketChannel;
	socketChannel.write(_responseBuffer);
	if (!_responseBuffer.hasRemaining()) {
		if (_response.hasUserBodyStream()) {
			final Selector selector = _server._selector;
			final XulHttpServerHandler attachment = this;
			socketChannel.register(selector, 0, attachment);
			selector.wakeup();
			_server._reactorPool.execute(new Runnable() {
				@Override
				public void run() {
					try {
						int beginOffset = _sendChunkedData ? 32 : 0;
						int endOffset = _sendChunkedData ? 2 : 0;
						int sizeLimit = _sendChunkedData ? 8192 : -1;
						if (_response == null || !_response.prepareUserBodyData(beginOffset, endOffset, sizeLimit)) {
							terminate();
							return;
						}
						int dataSize = _response.getDataSize();
						if (dataSize <= 0) {
							if (_sendChunkedData) {
								_response.writeStream(null);
								_responseBuffer = ByteBuffer.wrap("0\r\n\r\n".getBytes());
							} else {
								terminate();
								return;
							}
						} else {
							final byte[] data = _response.getData();
							if (_sendChunkedData) {
								String dataLength = String.format("%X\r\n", dataSize);
								final byte[] dataLengthBytes = dataLength.getBytes();
								beginOffset -= dataLengthBytes.length;
								System.arraycopy(dataLengthBytes, 0, data, beginOffset, dataLengthBytes.length);
								dataSize += dataLengthBytes.length;
								data[beginOffset + dataSize++] = '\r';
								data[beginOffset + dataSize++] = '\n';
							}
							_responseBuffer = ByteBuffer.wrap(data, beginOffset, dataSize);
						}
						socketChannel.register(selector, SelectionKey.OP_WRITE, attachment);
						selector.wakeup();
					} catch (Exception e) {
						terminate();
						XulLog.e(TAG, e);
					}
				}
			});
		} else {
			socketChannel.close();
		}
		return;
	}
}
 

public void setInterestOps(final AbstractNioChannel<?> channel, final ChannelFuture future, final int interestOps) {
    boolean iothread = isIoThread(channel);
    if (!iothread) {
        channel.getPipeline().execute(new Runnable() {
            public void run() {
                setInterestOps(channel, future, interestOps);
            }
        });
        return;
    }

    boolean changed = false;
    try {
        Selector selector = this.selector;
        SelectionKey key = channel.channel.keyFor(selector);

        // Override OP_WRITE flag - a user cannot change this flag.
        int newInterestOps = interestOps & ~Channel.OP_WRITE | channel.getRawInterestOps() & Channel.OP_WRITE;

        if (key == null || selector == null) {
            if (channel.getRawInterestOps() != newInterestOps) {
                changed = true;
            }

            // Not registered to the worker yet.
            // Set the rawInterestOps immediately; RegisterTask will pick it up.
            channel.setRawInterestOpsNow(newInterestOps);

            future.setSuccess();
            if (changed) {
                if (iothread) {
                    fireChannelInterestChanged(channel);
                } else {
                    fireChannelInterestChangedLater(channel);
                }
            }

            return;
        }

        if (channel.getRawInterestOps() != newInterestOps) {
            changed = true;
            key.interestOps(newInterestOps);
            if (Thread.currentThread() != thread &&
                wakenUp.compareAndSet(false, true)) {
                selector.wakeup();
            }
            channel.setRawInterestOpsNow(newInterestOps);
        }

        future.setSuccess();
        if (changed) {
            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);
    }
}
 

@Override
public Peer connect(InetSocketAddress address, Node node) throws IOException
{
    Selector srvSel = serverSelector;
    Peer peer;
    if (srvSel != null)
    {
        SocketChannel socketChannel = null;
        try
        {
            socketChannel = SocketChannel.open();
            socketChannel.configureBlocking(false);
            socketChannel.socket().setTcpNoDelay(true);
            String peerId = address.getAddress().getHostAddress() + ":" + address.getPort();
            SelectionKey connKey;
            synchronized (syncObj)
            {
                srvSel.wakeup();
                boolean connected = socketChannel.connect(address);
                if (connected)
                {
                    // if connect is true, we will never receive an OP_CONNECT
                    // even if we register for it.
                    // as the controller does not know about this peer (we didnt return yet)
                    // we will register for no operation.
                    // As soon as the controller tries to send a message, that will trigger the OP_WRITE anyways
                    connKey = socketChannel.register(srvSel, 0);
                }
                else
                {
                    // if connect returns false we will receive OP_CONNECT
                    // and we will need to call the finishConnection()
                    connKey = socketChannel.register(srvSel, OP_CONNECT);
                }
                peer = createTcpConnectorPeer(peerId, connKey, true, node);
                connKey.attach(peer);
                if (connected)
                {
                    // May throw SSLException
                    peer.connectionEstablished();
                    connObserver.outboundConnectionEstablished(peer);
                }
                else
                {
                    connObserver.outboundConnectionEstablishing(peer);
                }
                try
                {
                    node.setPeer(privilegedAccCtx, peer);
                }
                catch (AccessDeniedException accDeniedExc)
                {
                    throw new ImplementationError(
                        "TcpConnectorService privileged access context not authorized for node.setPeer() " +
                        "called from connect()",
                        accDeniedExc
                    );
                }
            }
        }
        catch (IOException ioExc)
        {
            try
            {
                if (socketChannel != null)
                {
                    socketChannel.close();
                }
            }
            catch (IOException ignored)
            {
            }
            throw ioExc;
        }
        catch (IllegalBlockingModeException blkModeException)
        {
            throw new IOException(
                "Connect request failed - Non-blocking I/O mode requested, but not supported"
            );
        }
        catch (IllegalSelectorException | ClosedSelectorException |
               CancelledKeyException connExc)
        {
            throw new IOException(
                "Connect request failed - Connector service '" + serviceInstanceName + "' state changed " +
                "while the operation was in progress"
            );
        }
    }
    else
    {
        throw new IOException(
            "Connect request failed - Connector service '" + serviceInstanceName + "' is stopped"
        );
    }
    return peer;
}