Examples with Selector java.nio.channels.Selector used on opensource projects

Example 6 with Selector

use of java.nio.channels.Selector in project netty by netty.

the class NioEventLoop method select.

private void select(boolean oldWakenUp) throws IOException {
    Selector selector = this.selector;
    try {
        int selectCnt = 0;
        long currentTimeNanos = System.nanoTime();
        long selectDeadLineNanos = currentTimeNanos + delayNanos(currentTimeNanos);
        for (; ; ) {
            long timeoutMillis = (selectDeadLineNanos - currentTimeNanos + 500000L) / 1000000L;
            if (timeoutMillis <= 0) {
                if (selectCnt == 0) {
                    selector.selectNow();
                    selectCnt = 1;
                }
                break;
            }
            // It might be pended until idle timeout if IdleStateHandler existed in pipeline.
            if (hasTasks() && wakenUp.compareAndSet(false, true)) {
                selector.selectNow();
                selectCnt = 1;
                break;
            }
            int selectedKeys = selector.select(timeoutMillis);
            selectCnt++;
            if (selectedKeys != 0 || oldWakenUp || wakenUp.get() || hasTasks() || hasScheduledTasks()) {
                // - a scheduled task is ready for processing
                break;
            }
            if (Thread.interrupted()) {
                // See https://github.com/netty/netty/issues/2426
                if (logger.isDebugEnabled()) {
                    logger.debug("Selector.select() returned prematurely because " + "Thread.currentThread().interrupt() was called. Use " + "NioEventLoop.shutdownGracefully() to shutdown the NioEventLoop.");
                }
                selectCnt = 1;
                break;
            }
            long time = System.nanoTime();
            if (time - TimeUnit.MILLISECONDS.toNanos(timeoutMillis) >= currentTimeNanos) {
                // timeoutMillis elapsed without anything selected.
                selectCnt = 1;
            } else if (SELECTOR_AUTO_REBUILD_THRESHOLD > 0 && selectCnt >= SELECTOR_AUTO_REBUILD_THRESHOLD) {
                // The selector returned prematurely many times in a row.
                // Rebuild the selector to work around the problem.
                logger.warn("Selector.select() returned prematurely {} times in a row; rebuilding Selector {}.", selectCnt, selector);
                rebuildSelector();
                selector = this.selector;
                // Select again to populate selectedKeys.
                selector.selectNow();
                selectCnt = 1;
                break;
            }
            currentTimeNanos = time;
        }
        if (selectCnt > MIN_PREMATURE_SELECTOR_RETURNS) {
            if (logger.isDebugEnabled()) {
                logger.debug("Selector.select() returned prematurely {} times in a row for Selector {}.", selectCnt - 1, selector);
            }
        }
    } catch (CancelledKeyException e) {
        if (logger.isDebugEnabled()) {
            logger.debug(CancelledKeyException.class.getSimpleName() + " raised by a Selector {} - JDK bug?", selector, e);
        }
    // Harmless exception - log anyway
    }
}

Example 7 with Selector

use of java.nio.channels.Selector in project opennms by OpenNMS.

the class SelectorTrackerTest method test.

@Test
public void test() throws IOException {
    Selector selector = Selector.open();
    assertTrue(selector.isOpen());
    selector.close();
    assertFalse(selector.isOpen());
    DatagramChannel c = DatagramChannel.open();
    DatagramSocket s = c.socket();
    s.setSoTimeout(1000);
    byte[] buf = new byte[1024];
    DatagramPacket p = new DatagramPacket(buf, 1024, InetAddress.getLocalHost(), 7);
    s.send(p);
}

Example 8 with Selector

use of java.nio.channels.Selector in project voltdb by VoltDB.

the class TLSHandshaker method handshake.

public boolean handshake() throws IOException {
    ByteBuffer txNetData = (ByteBuffer) ByteBuffer.allocate(m_appsz).clear();
    ByteBuffer clearData = (ByteBuffer) ByteBuffer.allocate(CipherExecutor.FRAME_SIZE).clear();
    SSLEngineResult result = null;
    m_eng.beginHandshake();
    HandshakeStatus status = m_eng.getHandshakeStatus();
    boolean isBlocked = m_sc.isBlocking();
    synchronized (m_sc.blockingLock()) {
        isBlocked = m_sc.isBlocking();
        if (isBlocked) {
            m_sc.configureBlocking(false);
        }
    }
    Selector selector = Selector.open();
    m_sc.register(selector, SelectionKey.OP_READ);
    try {
        while (status != HandshakeStatus.FINISHED && status != HandshakeStatus.NOT_HANDSHAKING) {
            switch(status) {
                case NEED_UNWRAP:
                    if (selector.select(2) == 1 && canread(selector)) {
                        if (m_sc.read(m_rxNetData) < 0) {
                            if (m_eng.isInboundDone() && m_eng.isOutboundDone()) {
                                return false;
                            }
                            try {
                                m_eng.closeInbound();
                            } catch (SSLException ingnoreIt) {
                            }
                            m_eng.closeOutbound();
                            status = m_eng.getHandshakeStatus();
                            break;
                        }
                    }
                    m_rxNetData.flip();
                    try {
                        result = m_eng.unwrap(m_rxNetData, clearData);
                        m_rxNetData.compact();
                        status = m_eng.getHandshakeStatus();
                    } catch (SSLException e) {
                        m_eng.closeOutbound();
                        throw e;
                    }
                    switch(result.getStatus()) {
                        case OK:
                            break;
                        case BUFFER_OVERFLOW:
                            clearData = expand(clearData, false);
                            break;
                        case BUFFER_UNDERFLOW:
                            // in this state until data shows up in m_rxNetData.
                            break;
                        case CLOSED:
                            if (m_eng.isOutboundDone()) {
                                return false;
                            } else {
                                m_eng.closeOutbound();
                                status = m_eng.getHandshakeStatus();
                            }
                            break;
                        default:
                            throw new IllegalStateException("Invalid SSL status: " + result.getStatus());
                    }
                    break;
                case NEED_WRAP:
                    txNetData.clear();
                    try {
                        result = m_eng.wrap(clearData, txNetData);
                        status = m_eng.getHandshakeStatus();
                    } catch (SSLException e) {
                        m_eng.closeOutbound();
                        throw e;
                    }
                    switch(result.getStatus()) {
                        case OK:
                            txNetData.flip();
                            while (txNetData.hasRemaining()) {
                                m_sc.write(txNetData);
                            }
                            break;
                        case BUFFER_OVERFLOW:
                            clearData = expand(txNetData, false);
                            break;
                        case BUFFER_UNDERFLOW:
                            throw new SSLException("Buffer underflow occured after a wrap");
                        case CLOSED:
                            txNetData.flip();
                            while (txNetData.hasRemaining()) {
                                m_sc.write(txNetData);
                            }
                            m_rxNetData.clear();
                            status = m_eng.getHandshakeStatus();
                            break;
                        default:
                            throw new IllegalStateException("Invalid SSL status: " + result.getStatus());
                    }
                    break;
                case NEED_TASK:
                    Runnable task;
                    while ((task = m_eng.getDelegatedTask()) != null) {
                        task.run();
                    }
                    status = m_eng.getHandshakeStatus();
                    break;
                case FINISHED:
                    break;
                case NOT_HANDSHAKING:
                    break;
                default:
                    throw new IllegalStateException("Invalid SSL handshake status" + status);
            }
        }
    } finally {
        SelectionKey sk = m_sc.keyFor(selector);
        sk.cancel();
        selector.close();
        if (isBlocked)
            synchronized (m_sc.blockingLock()) {
                m_sc.configureBlocking(isBlocked);
            }
    }
    return true;
}

Example 9 with Selector

use of java.nio.channels.Selector in project yyl_example by Relucent.

the class Receive method main.

public static void main(String[] args) throws Exception {
    ByteBuffer buffer = ByteBuffer.allocate(1024);
    ServerSocketChannel ss = ServerSocketChannel.open();
    ss.socket().bind(new InetSocketAddress(9998));
    ss.configureBlocking(false);
    Selector se = Selector.open();
    ss.register(se, SelectionKey.OP_ACCEPT);
    while (se.select() > 0) {
        Set<SelectionKey> set = se.selectedKeys();
        for (SelectionKey key : set) {
            System.out.println("-------------");
            SocketChannel sc = null;
            try {
                if (key.isAcceptable()) {
                    sc = ss.accept();
                    System.err.println("ACCEPTABLE:" + sc.socket());
                    sc.configureBlocking(false);
                    sc.register(se, SelectionKey.OP_READ);
                } else if (key.isReadable()) {
                    sc = (SocketChannel) key.channel();
                    System.out.println(sc.isConnected());
                    sc.read(buffer);
                    buffer.flip();
                    System.out.println(new String(buffer.array(), 0, buffer.remaining()));
                    sc.write(ByteBuffer.wrap("+".getBytes()));
                }
            } catch (Exception e) {
                key.cancel();
                if (sc != null) {
                    sc.close();
                }
                e.printStackTrace();
            }
        }
        set.clear();
    }
}

Example 10 with Selector

use of java.nio.channels.Selector in project yyl_example by Relucent.

the class Send method main.

public static void main(String[] args) throws Exception {
    SocketChannel socketChannel = SocketChannel.open();
    socketChannel.configureBlocking(false);
    Selector selector = Selector.open();
    socketChannel.register(selector, SelectionKey.OP_CONNECT | SelectionKey.OP_READ | SelectionKey.OP_WRITE);
    socketChannel.connect(new InetSocketAddress("127.0.0.1", 9998));
    while (!socketChannel.finishConnect()) {
    }
    ByteBuffer buffer = ByteBuffer.allocate(1024);
    socketChannel.write(ByteBuffer.wrap("-".getBytes()));
    int index = 0;
    while (true) {
        if (selector.select() == 0) {
            Thread.sleep(1000);
            continue;
        }
        Set<SelectionKey> set = selector.selectedKeys();
        for (SelectionKey key : set) {
            int ops = key.readyOps();
            if ((ops & SelectionKey.OP_CONNECT) == SelectionKey.OP_CONNECT) {
                socketChannel.write(buffer);
                System.out.println("OP_CONNECT:");
            }
            if ((ops & SelectionKey.OP_READ) == SelectionKey.OP_READ) {
                socketChannel.read(buffer);
                buffer.flip();
                System.out.println(new String(buffer.array(), 0, buffer.remaining()));
                buffer.clear();
                socketChannel.write(ByteBuffer.wrap(("No-" + index + " | ").getBytes()));
                index++;
            }
        }
        set.clear();
        Thread.sleep(1000);
    }
}