EventListener监听器源码浅析

1.AbstractBootstrap

private static void doBind0(final ChannelFuture regFuture, final Channel channel, final SocketAddress localAddress, final ChannelPromise promise) {
channel.eventLoop().execute(new Runnable() {
public void run() {
if (regFuture.isSuccess()) {
channel.bind(localAddress,
// 此处加了监听器
promise).addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
} else {
promise.setFailure(regFuture.cause());
}

        }
    });
}

2. AbstractChannel.AbstractUnsafe

public final void bind(SocketAddress localAddress, ChannelPromise promise) {
           ....

                // 此处调用了
                this.safeSetSuccess(promise);
            }
        }

3.AbstractChannel

protected final void safeSetSuccess(ChannelPromise promise) {
// trySuccess
            if (!(promise instanceof VoidChannelPromise) && !promise.trySuccess()) {
                AbstractChannel.logger.warn("Failed to mark a promise as success because it is done already: {}", promise);
            }

        }

DefaultChannelPromise

public boolean trySuccess() {
        return this.trySuccess((Object)null);
    }

DefaultPromise

public boolean trySuccess(V result) {
        if (this.setSuccess0(result)) {
            this.notifyListeners();
            return true;
        } else {
            return false;
        }
    }

private void notifyListeners() {
        EventExecutor executor = this.executor();
        if (executor.inEventLoop()) {
            InternalThreadLocalMap threadLocals = InternalThreadLocalMap.get();
            int stackDepth = threadLocals.futureListenerStackDepth();
            if (stackDepth < MAX_LISTENER_STACK_DEPTH) {
                threadLocals.setFutureListenerStackDepth(stackDepth + 1);

                try {
// 这里
                    this.notifyListenersNow();
                } finally {
                    threadLocals.setFutureListenerStackDepth(stackDepth);
                }

                return;
            }
        }

        safeExecute(executor, new Runnable() {
            public void run() {
                DefaultPromise.this.notifyListenersNow();
            }
        });
    }

// 再一路
private static void notifyListener0(Future future, GenericFutureListener l) {
        try {
// 最终就是这个，最后调用了事件
            l.operationComplete(future);
        } catch (Throwable var3) {
            logger.warn("An exception was thrown by " + l.getClass().getName() + ".operationComplete()", var3);
        }

    }