AbstractChannel Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/AbstractChannel.java lines 41–1095

public abstract class AbstractChannel extends DefaultAttributeMap implements Channel {

    private static final InternalLogger logger = InternalLoggerFactory.getInstance(AbstractChannel.class);

    private final Channel parent;
    private final ChannelId id;
    private final Unsafe unsafe;
    private final DefaultChannelPipeline pipeline;
    private final VoidChannelPromise unsafeVoidPromise = new VoidChannelPromise(this, false);
    private final CloseFuture closeFuture = new CloseFuture(this);

    private volatile SocketAddress localAddress;
    private volatile SocketAddress remoteAddress;
    private volatile EventLoop eventLoop;
    private volatile boolean registered;
    private boolean closeInitiated;
    private Throwable initialCloseCause;

    /** Cache for the string representation of this channel */
    private boolean strValActive;
    private String strVal;

    /**
     * Creates a new instance.
     *
     * @param parent
     *        the parent of this channel. {@code null} if there's no parent.
     */
    protected AbstractChannel(Channel parent) {
        this.parent = parent;
        id = newId();
        unsafe = newUnsafe();
        pipeline = newChannelPipeline();
    }

    /**
     * Creates a new instance.
     *
     * @param parent
     *        the parent of this channel. {@code null} if there's no parent.
     */
    protected AbstractChannel(Channel parent, ChannelId id) {
        this.parent = parent;
        this.id = id;
        unsafe = newUnsafe();
        pipeline = newChannelPipeline();
    }

    protected final int maxMessagesPerWrite() {
        ChannelConfig config = config();
        if (config instanceof DefaultChannelConfig) {
            return ((DefaultChannelConfig) config).getMaxMessagesPerWrite();
        }
        Integer value = config.getOption(ChannelOption.MAX_MESSAGES_PER_WRITE);
        if (value == null) {
            return Integer.MAX_VALUE;
        }
        return value;
    }

    @Override
    public final ChannelId id() {
        return id;
    }

    /**
     * Returns a new {@link DefaultChannelId} instance. Subclasses may override this method to assign custom
     * {@link ChannelId}s to {@link Channel}s that use the {@link AbstractChannel#AbstractChannel(Channel)} constructor.
     */
    protected ChannelId newId() {
        return DefaultChannelId.newInstance();
    }

    /**
     * Returns a new {@link DefaultChannelPipeline} instance.
     */
    protected DefaultChannelPipeline newChannelPipeline() {
        return new DefaultChannelPipeline(this);
    }

    @Override