Netty4源码分析--启动2

接上篇，分析bind

 

// AbstractBootstrap.java
private static void doBind0(
            final ChannelFuture regFuture, final Channel channel,
            final SocketAddress localAddress, final ChannelPromise promise) {

        // This method is invoked before channelRegistered() is triggered.  Give user handlers a chance to set up
        // the pipeline in its channelRegistered() implementation.
        channel.eventLoop().execute(new Runnable() {
            @Override
            public void run() {
                if (regFuture.isSuccess()) {
                    channel.bind(localAddress, promise).addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
                } else {
                    promise.setFailure(regFuture.cause());
                }
            }
        });
    }

// AbstractChannel.java
@Override
    public ChannelFuture bind(SocketAddress localAddress, ChannelPromise promise) {
        return pipeline.bind(localAddress, promise);
    }

// DefaultChannelPipeline.java
@Override
    public final ChannelFuture bind(SocketAddress localAddress, ChannelPromise promise) {
        return tail.bind(localAddress, promise);
    }

@Override
        public void bind(
                ChannelHandlerContext ctx, SocketAddress localAddress, ChannelPromise promise)
                throws Exception {
            unsafe.bind(localAddress, promise);
        }

// AbstractChannel.java--AbstractUnsafe
@Override
        public final void bind(final SocketAddress localAddress, final ChannelPromise promise) {
            assertEventLoop();

            if (!promise.setUncancellable() || !ensureOpen(promise)) {
                return;
            }

            // See: https://github.com/netty/netty/issues/576
            if (Boolean.TRUE.equals(config().getOption(ChannelOption.SO_BROADCAST)) &&
                localAddress instanceof InetSocketAddress &&
                !((InetSocketAddress) localAddress).getAddress().isAnyLocalAddress() &&
                !PlatformDependent.isWindows() && !PlatformDependent.isRoot()) {
                // Warn a user about the fact that a non-root user can't receive a
                // broadcast packet on *nix if the socket is bound on non-wildcard address.
                logger.warn(
                        "A non-root user can't receive a broadcast packet if the socket " +
                        "is not bound to a wildcard address; binding to a non-wildcard " +
                        "address (" + localAddress + ") anyway as requested.");
            }

            boolean wasActive = isActive(); // 此时还没有绑定，返回false
            try {
                doBind(localAddress);
            } catch (Throwable t) {
                safeSetFailure(promise, t);
                closeIfClosed();
                return;
            }

            if (!wasActive && isActive()) {// 如果serverSocket还没被绑定好，就将激活任务加入boss的task队列
                invokeLater(new Runnable() {
                    @Override
                    public void run() {
                        pipeline.fireChannelActive();
                    }
                });
            }

            safeSetSuccess(promise); // TODO
        }

public boolean isActive() {
        return javaChannel().socket().isBound();
    }

// NioServerSocketChannel.java
protected void doBind(SocketAddress localAddress) throws Exception {
        javaChannel().socket().bind(localAddress, config.getBacklog());
    } // nio服务端绑定端口的操作

 

接着分析激活任务

// DefaultChannelPipeline.java
@Override
    public final ChannelPipeline fireChannelActive() {
        AbstractChannelHandlerContext.invokeChannelActive(head);
        return this;
    }

// AbstractChannelHandlerContext.java
static void invokeChannelActive(final AbstractChannelHandlerContext next) {
        EventExecutor executor = next.executor();
        if (executor.inEventLoop()) {
            next.invokeChannelActive();
        } else {
            executor.execute(new Runnable() {
                @Override
                public void run() {
                    next.invokeChannelActive();
                }
            });
        }
    }

private void invokeChannelActive() {
        if (invokeHandler()) {
            try {
                ((ChannelInboundHandler) handler()).channelActive(this);
            } catch (Throwable t) {
                notifyHandlerException(t);
            }
        } else {
            fireChannelActive();
        }
    }

// head--ServerBootstrapAcceptor--tail
// head
public void channelActive(ChannelHandlerContext ctx) throws Exception {
            ctx.fireChannelActive();

            readIfIsAutoRead(); // 如果channel的config被设为autoread==true，注册对读事件感兴趣
        }

// ServerBootstrapAcceptor
// ChannelInboundHandlerAdapter.java
public void channelActive(ChannelHandlerContext ctx) throws Exception {
        ctx.fireChannelActive(); // 调下一个
    }

// tail，什么也没做

至此，netty服务端启动完成，boss线程就在循环等待处理io和非io任务，接下来就是netty线程模型的分析