目录

• NioSocketChannel的创建
• 回到上一小节的read()方法
• 我们首先看readBuf
• jdk底层相关的内容
• 跟到父类构造方法中
• 我们跟进其构造方法

前文传送门：Netty客户端处理接入事件handle创建

NioSocketChannel的创建
回到上一小节的read()方法

public void read() {//必须是NioEventLoop方法调用的, 不能通过外部线程调用assert eventLoop().inEventLoop(); //服务端channel的configfinal ChannelConfig config = config(); //服务端channel的pipelinefinal ChannelPipeline pipeline = pipeline(); //处理服务端接入的速率final RecvByteBufAllocator.Handle allocHandle = unsafe().recvBufAllocHandle(); //设置配置allocHandle.reset(config); boolean closed = false; Throwable exception = null; try {try {do {//创建jdk底层的channel//readBuf用于临时承载读到链接int localRead = doReadMessages(readBuf); if (localRead == 0) {break; }if (localRead < 0) {closed = true; break; }//分配器将读到的链接进行计数allocHandle.incMessagesRead(localRead); //连接数是否超过最大值} while (allocHandle.continueReading()); } catch (Throwable t) {exception = t; }int size = readBuf.size(); //遍历每一条客户端连接for (int i = 0; i < size; i ++) {readPending = false; //传递事件, 将创建NioSokectChannel进行传递//最终会调用ServerBootstrap的内部类ServerBootstrapAcceptor的channelRead()方法pipeline.fireChannelRead(readBuf.get(i)); }readBuf.clear(); allocHandle.readComplete(); pipeline.fireChannelReadComplete(); //代码省略} finally {//代码省略}}

我们继续剖析int localRead = doReadMessages(readBuf)这一部分逻辑

我们首先看readBuf

private final List