NioServerDomainSocketChannel Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/socket/nio/NioServerDomainSocketChannel.java lines 53–283

public final class NioServerDomainSocketChannel extends AbstractNioMessageChannel
        implements io.netty.channel.ServerChannel {
    private static final Method OPEN_SERVER_SOCKET_CHANNEL_WITH_FAMILY =
            SelectorProviderUtil.findOpenMethod("openServerSocketChannel");
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(NioServerDomainSocketChannel.class);
    private static final ChannelMetadata METADATA = new ChannelMetadata(false, 16);
    private static final SelectorProvider DEFAULT_SELECTOR_PROVIDER = SelectorProvider.provider();
    private final NioDomainServerSocketChannelConfig config;
    private volatile boolean bound;

    // Package-private for testing.
    static ServerSocketChannel newChannel(SelectorProvider provider) {
        if (PlatformDependent.javaVersion() < 16) {
            throw new UnsupportedOperationException("Only supported with Java 16+");
        }
        try {
            ServerSocketChannel channel =
                    SelectorProviderUtil.newDomainSocketChannel(OPEN_SERVER_SOCKET_CHANNEL_WITH_FAMILY, provider);
            if (channel == null) {
                throw new ChannelException("Failed to open a socket.");
            }
            return channel;
        } catch (IOException e) {
            throw new ChannelException("Failed to open a socket.", e);
        }
    }

    @Override
    protected ServerSocketChannel javaChannel() {
        return (ServerSocketChannel) super.javaChannel();
    }

    /**
     * Create a new instance
     */
    public NioServerDomainSocketChannel() {
        this(DEFAULT_SELECTOR_PROVIDER);
    }

    /**
     * Create a new instance using the given {@link SelectorProvider}.
     */
    public NioServerDomainSocketChannel(SelectorProvider provider) {
        this(newChannel(provider));
    }

    /**
     * Create a new instance using the given {@link ServerSocketChannel}.
     */
    public NioServerDomainSocketChannel(ServerSocketChannel channel) {
        super(null, channel, SelectionKey.OP_ACCEPT);
        if (PlatformDependent.javaVersion() < 16) {
            throw new UnsupportedOperationException("Only supported with Java 16+");
        }
        config = new NioDomainServerSocketChannelConfig(this);
        try {
            // Check if we already have a local address bound.
            bound = channel.getLocalAddress() != null;
        } catch (IOException e) {
            throw new ChannelException(e);
        }
    }

    @Override
    public ChannelConfig config() {
        return config;
    }

    @Override
    public ChannelMetadata metadata() {
        return METADATA;
    }

    @Override
    public boolean isActive() {
        // As java.nio.ServerSocketChannel.isBound() will continue to return true even after the channel was closed
        // we will also need to check if it is open.
        return isOpen() && bound;
    }

    @Override