陈老哥-源码分析-1

来源：互联网发布：宫颈糜烂不是病知乎编辑：程序博客网时间：2024/04/29 11:44

https://github.com/chenshuo/muduo

int main(int argc, char* argv[])
{
int numThreads = 0;
if (argc > 1)
{
benchmark = true;
Logger::setLogLevel(Logger::WARN);
numThreads = atoi(argv[1]);
}
EventLoop loop;
HttpServer server(&loop, InetAddress(8000), "dummy");
server.setHttpCallback(onRequest);
server.setThreadNum(numThreads);
server.start();
loop.loop();
}

对于one thread one loop而言，上面的所有操作无非是将socketfd的Channel加入EPollPoller::channels_中，以及将socketfd加入epoll监听集合中；

EventLoop::loop()作用是，EPollPoller 类的poll 函数会收集所有发生事件的socketfd 的Channel存于activeChannels_ 中，因为每一个socketfd 在对应的Channel 中会设置读/写/及错误发生时候的回调函数的;接着遍历收集到的activeChannels_ , 并执行每一个Channel 的handleEvent 进而去调用设置的回调函数;当别的类想异步执行某个函数时候只需要调用EventLoop::runInLoop(const Functor& cb)该函数里面会判断如果执行该函数的线程与主线程不同则利用往evtfd 中写个字符触发epoll , 继而doPendingFunctors();得到执行了,即会执行上层注册的函数cb。

PollPoller.h

// Copyright 2010, Shuo Chen.  All rights reserved.// http://code.google.com/p/muduo///// Use of this source code is governed by a BSD-style license// that can be found in the License file.// Author: Shuo Chen (chenshuo at chenshuo dot com)//// This is an internal header file, you should not include this.#ifndef MUDUO_NET_POLLER_H#define MUDUO_NET_POLLER_H#include <vector>#include <boost/noncopyable.hpp>#include <muduo/base/Timestamp.h>#include <muduo/net/EventLoop.h>namespace muduo{namespace net{class Channel;////// Base class for IO Multiplexing////// This class doesn't own the Channel objects.class Poller : boost::noncopyable{ public:  typedef std::vector<Channel*> ChannelList;  Poller(EventLoop* loop);  virtual ~Poller();  /// Polls the I/O events.  /// Must be called in the loop thread.  virtual Timestamp poll(int timeoutMs, ChannelList* activeChannels) = 0;  /// Changes the interested I/O events.  /// Must be called in the loop thread.  virtual void updateChannel(Channel* channel) = 0;  /// Remove the channel, when it destructs.  /// Must be called in the loop thread.  virtual void removeChannel(Channel* channel) = 0;  static Poller* newDefaultPoller(EventLoop* loop);  void assertInLoopThread()  {    ownerLoop_->assertInLoopThread();  } private:  EventLoop* ownerLoop_;};}}#endif  // MUDUO_NET_POLLER_H

需要弄清楚下面几个类：

class Channel; /*一个fd，对应一个Channel，该Channel中会给fd注册读、写、错误发生时候的处理函数的*/

boost::noncopyable /*在子类没有重写拷贝构造和赋值重载时候，子类对象是不允许进行赋值或者调用子类拷贝构造的*/

EventLoop /*无限循环中当epoll_wait()返回时候，将所有的Channel收集并存于activeChannels_中，接着就是执行activeChannels_中的每个Channel->handleEvent(),而改函数中会调用该Channel类对象的函数即给fd注册读、写、错误发生的处理函数*/

Timestamp /*利用微秒获得时间的*/

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