EpollDatagramChannel Class — netty Architecture

Source Code

transport-classes-epoll/src/main/java/io/netty/channel/epoll/EpollDatagramChannel.java lines 61–818

public final class EpollDatagramChannel extends AbstractEpollChannel implements DatagramChannel {
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(EpollDatagramChannel.class);
    private static final boolean IP_MULTICAST_ALL =
            SystemPropertyUtil.getBoolean("io.netty.channel.epoll.ipMulticastAll", false);
    private static final ChannelMetadata METADATA = new ChannelMetadata(true, 16);
    private static final String EXPECTED_TYPES =
            " (expected: " + StringUtil.simpleClassName(DatagramPacket.class) + ", " +
            StringUtil.simpleClassName(AddressedEnvelope.class) + '<' +
            StringUtil.simpleClassName(ByteBuf.class) + ", " +
            StringUtil.simpleClassName(InetSocketAddress.class) + ">, " +
            StringUtil.simpleClassName(ByteBuf.class) + ')';

    private final EpollDatagramChannelConfig config;
    private volatile boolean connected;

    static {
        if (logger.isDebugEnabled()) {
            logger.debug("-Dio.netty.channel.epoll.ipMulticastAll: {}", IP_MULTICAST_ALL);
        }
    }

    /**
     * Returns {@code true} if {@link io.netty.channel.unix.SegmentedDatagramPacket} is supported natively.
     *
     * @return {@code true} if supported, {@code false} otherwise.
     */
    public static boolean isSegmentedDatagramPacketSupported() {
        return Epoll.isAvailable() &&
                // We only support it together with sendmmsg(...)
                Native.IS_SUPPORTING_SENDMMSG && Native.IS_SUPPORTING_UDP_SEGMENT;
    }

    /**
     * Create a new instance which selects the {@link SocketProtocolFamily} to use depending
     * on the Operation Systems default which will be chosen.
     */
    public EpollDatagramChannel() {
        this((SocketProtocolFamily) null);
    }

    /**
     * Create a new instance using the given {@link InternetProtocolFamily}. If {@code null} is used it will depend
     * on the Operation Systems default which will be chosen.
     *
     * @deprecated use {@link EpollDatagramChannel#EpollDatagramChannel(SocketProtocolFamily)}
     */
    @Deprecated
    public EpollDatagramChannel(InternetProtocolFamily family) {
        this(newSocketDgram(family), false);
    }

    /**
     * Create a new instance using the given {@link SocketProtocolFamily}. If {@code null} is used it will depend
     * on the Operation Systems default which will be chosen.
     */
    public EpollDatagramChannel(SocketProtocolFamily family) {
        this(newSocketDgram(family), false);
    }

    /**
     * Create a new instance which selects the {@link SocketProtocolFamily} to use depending
     * on the Operation Systems default which will be chosen.
     */
    public EpollDatagramChannel(int fd) {
        this(new LinuxSocket(fd), true);
    }

    private EpollDatagramChannel(LinuxSocket fd, boolean active) {
        super(null, fd, active, EpollIoOps.valueOf(0));

        // Configure IP_MULTICAST_ALL - disable by default to match the behaviour of NIO.
        try {
            fd.setIpMulticastAll(IP_MULTICAST_ALL);
        } catch (IOException | ChannelException e) {
            logger.debug("Failed to set IP_MULTICAST_ALL to {}", IP_MULTICAST_ALL, e);
        }

        config = new EpollDatagramChannelConfig(this);
    }

    @Override