Netty启动流程服务端channel初始化源码分析

final ChannelFuture initAndRegister() {

     Channel channel = null ;

     try {

         //创建channel

         channel = channelFactory.newChannel();

         //初始化channel

         init(channel);

     } catch (Throwable t) {

         //忽略非关键代码

     }

     ChannelFuture regFuture = config().group().register(channel);

     //忽略非关键代码

     return regFuture;

}

void init(Channel channel) throws Exception {

     //获取用户定义的选项(1)

     final Map<ChannelOption<?>, Object> options = options0();

     synchronized (options) {

         channel.config().setOptions(options);

     }

     //获取用户定义的属性(2)

     final Map<AttributeKey<?>, Object> attrs = attrs0();

     synchronized (attrs) {

         for (Entry<AttributeKey<?>, Object> e: attrs.entrySet()) {

             @SuppressWarnings ( "unchecked" )

             AttributeKey<Object> key = (AttributeKey<Object>) e.getKey();

             channel.attr(key).set(e.getValue());

         }

     }

     //获取channel的pipline(3)

     ChannelPipeline p = channel.pipeline();

     //work线程组(4)

     final EventLoopGroup currentChildGroup = childGroup;

     //用户设置的Handler(5)

     final ChannelHandler currentChildHandler = childHandler;

     final Entry<ChannelOption<?>, Object>[] currentChildOptions;

     final Entry<AttributeKey<?>, Object>[] currentChildAttrs;

     //选项转化为Entry对象(6)

     synchronized (childOptions) {

         currentChildOptions = childOptions.entrySet().toArray(newOptionArray(childOptions.size()));

     }

     //属性转化为Entry对象(7)

     synchronized (childAttrs) {

         currentChildAttrs = childAttrs.entrySet().toArray(newAttrArray(childAttrs.size()));

     }

     //添加服务端handler(8)

     p.addLast( new ChannelInitializer<Channel>() {

         //初始化channel

         @Override

         public void initChannel(Channel ch) throws Exception {

             final ChannelPipeline pipeline = ch.pipeline();

             ChannelHandler handler = config.handler();

             if (handler != null ) {

                 pipeline.addLast(handler);

             }

             ch.eventLoop().execute( new Runnable() {

                 @Override

                 public void run() {

                     pipeline.addLast( new ServerBootstrapAcceptor(

                             currentChildGroup, currentChildHandler, currentChildOptions, currentChildAttrs));

                 }

             });

         }

     });

}