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

Example 46 with Selector

use of java.nio.channels.Selector in project ignite by apache.

the class GridNioServer method createSelector.

/**
 * Creates selector and binds server socket to a given address and port. If address is null
 * then will not bind any address and just creates a selector.
 *
 * @param addr Local address to listen on.
 * @return Created selector.
 * @throws IgniteCheckedException If selector could not be created or port is already in use.
 */
private Selector createSelector(@Nullable SocketAddress addr) throws IgniteCheckedException {
    Selector selector = null;
    ServerSocketChannel srvrCh = null;
    try {
        // Create a new selector
        selector = SelectorProvider.provider().openSelector();
        if (addr != null) {
            // Create a new non-blocking server socket channel
            srvrCh = ServerSocketChannel.open();
            srvrCh.configureBlocking(false);
            if (sockRcvBuf > 0)
                srvrCh.socket().setReceiveBufferSize(sockRcvBuf);
            // Bind the server socket to the specified address and port
            srvrCh.socket().bind(addr);
            // Register the server socket channel, indicating an interest in
            // accepting new connections
            srvrCh.register(selector, SelectionKey.OP_ACCEPT);
        }
        return selector;
    } catch (Throwable e) {
        U.close(srvrCh, log);
        U.close(selector, log);
        if (e instanceof Error)
            throw (Error) e;
        throw new IgniteCheckedException("Failed to initialize NIO selector.", e);
    }
}

Example 47 with Selector

use of java.nio.channels.Selector in project jetty.project by eclipse.

the class NIOTest method testSelector.

@Test
public void testSelector() throws Exception {
    ServerSocket acceptor = new ServerSocket(0);
    Selector selector = Selector.open();
    // Create client server socket pair
    SocketChannel client = SocketChannel.open(acceptor.getLocalSocketAddress());
    Socket server = acceptor.accept();
    server.setTcpNoDelay(true);
    // Make the client non blocking and register it with selector for reads
    client.configureBlocking(false);
    SelectionKey key = client.register(selector, SelectionKey.OP_READ);
    // assert it is not selected
    assertTrue(key.isValid());
    assertFalse(key.isReadable());
    assertEquals(0, key.readyOps());
    // try selecting and assert nothing selected
    int selected = selector.selectNow();
    assertEquals(0, selected);
    assertEquals(0, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertFalse(key.isReadable());
    assertEquals(0, key.readyOps());
    // Write a byte from server to client
    server.getOutputStream().write(42);
    server.getOutputStream().flush();
    // select again and assert selection found for read
    selected = selector.select(1000);
    assertEquals(1, selected);
    assertEquals(1, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertTrue(key.isReadable());
    assertEquals(1, key.readyOps());
    // select again and see that it is not reselect, but stays selected
    selected = selector.select(100);
    assertEquals(0, selected);
    assertEquals(1, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertTrue(key.isReadable());
    assertEquals(1, key.readyOps());
    // read the byte
    ByteBuffer buf = ByteBuffer.allocate(1024);
    int len = client.read(buf);
    assertEquals(1, len);
    buf.flip();
    assertEquals(42, buf.get());
    buf.clear();
    // But this does not change the key
    assertTrue(key.isValid());
    assertTrue(key.isReadable());
    assertEquals(1, key.readyOps());
    // Even if we select again ?
    selected = selector.select(100);
    assertEquals(0, selected);
    assertEquals(1, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertTrue(key.isReadable());
    assertEquals(1, key.readyOps());
    // Unless we remove the key from the select set
    // and then it is still flagged as isReadable()
    selector.selectedKeys().clear();
    assertEquals(0, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertTrue(key.isReadable());
    assertEquals(1, key.readyOps());
    // Now if we select again - it is still flagged as readable!!!
    selected = selector.select(100);
    assertEquals(0, selected);
    assertEquals(0, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertTrue(key.isReadable());
    assertEquals(1, key.readyOps());
    // Only when it is selected for something else does that state change.
    key.interestOps(SelectionKey.OP_READ | SelectionKey.OP_WRITE);
    selected = selector.select(1000);
    assertEquals(1, selected);
    assertEquals(1, selector.selectedKeys().size());
    assertTrue(key.isValid());
    assertTrue(key.isWritable());
    assertFalse(key.isReadable());
    assertEquals(SelectionKey.OP_WRITE, key.readyOps());
}

Example 48 with Selector

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

the class SocketAcceptorThread method rebuildSelector.

private void rebuildSelector() throws IOException {
    selectorRecreateCount.inc();
    // cancel existing selection key, register new one on the new selector
    selectionKey.cancel();
    closeSelector();
    Selector newSelector = Selector.open();
    selector = newSelector;
    selectionKey = serverSocketChannel.register(newSelector, SelectionKey.OP_ACCEPT);
}

Example 49 with Selector

use of java.nio.channels.Selector in project tomcat by apache.

the class NioReceiver method closeSelector.

private void closeSelector() throws IOException {
    Selector selector = this.selector.getAndSet(null);
    if (selector == null)
        return;
    try {
        Iterator<SelectionKey> it = selector.keys().iterator();
        // look at each key in the selected set
        while (it.hasNext()) {
            SelectionKey key = it.next();
            key.channel().close();
            key.attach(null);
            key.cancel();
        }
    } catch (IOException ignore) {
        if (log.isWarnEnabled()) {
            log.warn(sm.getString("nioReceiver.cleanup.fail"), ignore);
        }
    } catch (ClosedSelectorException ignore) {
    // Ignore
    }
    try {
        selector.selectNow();
    } catch (Throwable t) {
        ExceptionUtils.handleThrowable(t);
    // Ignore everything else
    }
    selector.close();
}

Example 50 with Selector

use of java.nio.channels.Selector in project tomcat by apache.

the class NioReceiver method stopListening.

/**
     * 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(sm.getString("nioReceiver.stop.fail"), x);
        } finally {
            this.selector.set(null);
        }
    }
}