Netty源码解析NioEventLoop创建的构造方法

protected MultithreadEventExecutorGroup(int nThreads, Executor executor, 
                                        EventExecutorChooserFactory chooserFactory, Object... args) {
    //代码省略
    if (executor == null) {
        //创建一个新的线程执行器(1)
        executor = new ThreadPerTaskExecutor(newDefaultThreadFactory());
    }
    //构造NioEventLoop(2)
    children = new EventExecutor[nThreads];
    for (int i = 0; i < nThreads; i ++) {
        boolean success = false;
        try {
            children[i] = newChild(executor, args);
            success = true;
        } catch (Exception e) {
            throw new IllegalStateException("failed to create a child event loop", e);
        } finally {
           //代码省略
        }
    }
    //创建线程选择器(3)
    chooser = chooserFactory.newChooser(children);
    //代码省略
}

NioEventLoop(NioEventLoopGroup parent, Executor executor, SelectorProvider selectorProvider, 
             SelectStrategy strategy, RejectedExecutionHandler rejectedExecutionHandler) {
    super(parent, executor, false, DEFAULT_MAX_PENDING_TASKS, rejectedExecutionHandler);
    //代码省略
    provider = selectorProvider;
    selector = openSelector();
    selectStrategy = strategy;
}

protected SingleThreadEventLoop(EventLoopGroup parent, Executor executor, 
                                boolean addTaskWakesUp, int maxPendingTasks, 
                                RejectedExecutionHandler rejectedExecutionHandler) {
    super(parent, executor, addTaskWakesUp, maxPendingTasks, rejectedExecutionHandler);
    tailTasks = newTaskQueue(maxPendingTasks);
}

protected SingleThreadEventExecutor(EventExecutorGroup parent, Executor executor, 
                                    boolean addTaskWakesUp, int maxPendingTasks, 
                                    RejectedExecutionHandler rejectedHandler) {
    super(parent);
    this.addTaskWakesUp = addTaskWakesUp;
    this.maxPendingTasks = Math.max(16, maxPendingTasks);
    this.executor = ObjectUtil.checkNotNull(executor, "executor");
    taskQueue = newTaskQueue(this.maxPendingTasks);
    rejectedExecutionHandler = ObjectUtil.checkNotNull(rejectedHandler, "rejectedHandler");
}