【MUDUO】打包EventLoop和Thread

EventLoopThread.h

#pragma once 
#include "noncopyable.h"
#include "Thread.h"
#include <functional>
#include <mutex>
#include <condition_variable>
#include <string>

class EventLoop;

class EventLoopThread:noncopyable
{
    public:
        using ThreadInitCallback = std::function<void(EventLoop*)>;

        EventLoopThread(const ThreadInitCallback& cb = ThreadInitCallback(), 
                    const std::string &name = std::string()
        );

        ~EventLoopThread();
        //开启循环
        EventLoop* startLoop();

    private:
        void threadFunc();
        
        //事件循环
        EventLoop *loop_;
        //是否退出循环
        bool exiting_;
        //线程
        Thread thread_;
        //加锁
        std::mutex mutex_;
        //条件变量
        std::condition_variable cond_;
        //回调函数初始化
        ThreadInitCallback callback_;
};

EventLoopThread.cc

#include "EventLoopThread.h"
#include "EventLoop.h"



EventLoopThread::EventLoopThread(const ThreadInitCallback& cb , const std::string &name)
    :loop_(nullptr) //是空的才会去创建一个线程
    ,exiting_(false)
    ,thread_(std::bind(&EventLoopThread::threadFunc, this),name)
    ,mutex_()
    ,cond_()
    ,callback_(cb)
{

}

EventLoopThread::~EventLoopThread()
{
    exiting_ = true;
    if(loop_ == nullptr)
    {
        loop_->quit();
        thread_.join();
    }
}
//开启循环
EventLoop* EventLoopThread::startLoop()
{
    thread_.start();// 启动底层的线程
    EventLoop *loop = nullptr;
    {
        std::unique_lock<std::mutex> lock(mutex_);
        //等待线程创建成功void EventLoopThread::threadFunc() 的cond_.notify_one();通知
        while(loop_ == nullptr)
        {
            cond_.wait(lock); //等待通知
        }
        loop = loop_;
    }
    return loop;

}

//这个是线程创建，并且开始Poller中的poll
void EventLoopThread::threadFunc()
{
    EventLoop loop; //创建一个独立的EventLoop，和上面的线程一一对应
    if(callback_)
    {
        callback_(&loop);
    }
    {
        std::unique_lock<std::mutex> lock(mutex_);
        loop_ = &loop;
        cond_.notify_one(); //通知创建线程完成
    }
    loop.loop(); //此处开启了事件循环,
    //到这里来证明服务器要关闭这个线程了
    std::unique_lock<std::mutex> lock(mutex_);
    loop_ = nullptr;
    
}