netty之NioEventLoop和NioEventLoopGroup

类结构图

NioEventLoopGroup

NioEventLoop

初始化

线程池创建是通过MultithreadEventExecutorGroup构造函数，创建线程是通过DefaultThreadFactory
首先创建EventExecutor的数组

children = new EventExecutor[nThreads];

NioEventLoopGroup的newChild创建具体的eventloop即NioEventLoop
SingleThreadEventExecutor在重写了线程池的execute方法时，其会创建线程，执行SingleThreadEventExecutor.this.run()抽象方法
同时会初始化EventExecutorChooser, 有两种类型

• PowerOfTwoEventExecutorChooser
• GenericEventExecutorChooser

初始化SelectorProvider，默认使用sun.nio.ch.DefaultSelectorProvider.create()

public static SelectorProvider provider() {synchronized (lock) {if (provider != null)return provider;return AccessController.doPrivileged(new PrivilegedAction<SelectorProvider>() {public SelectorProvider run() {if (loadProviderFromProperty())return provider;if (loadProviderAsService())return provider;provider = sun.nio.ch.DefaultSelectorProvider.create();return provider;}});}}

初始化DefaultSelectStrategy，默认使用SelectStrategy.SELECT
创建NioEventLoop传递的executor参数为ThreadPerTaskExecutor