缩略muduo库（5）：Thread、EventThread、EventThreadPool

文章目录

Thread

#pragma once

#include "nocopyable.hpp"

#include <functional>
#include <thread>
#include <memory>
#include <unistd.h>
#include <string>
#include <atomic>

class Thread:public nocpoyable{
public:
    using ThreadFunc = std::function<void()>;
    explicit Thread(ThreadFunc func,const std::string &name);
    ~Thread();

    void start();
    void join();

    bool started() const{return started_;}
    pid_t tid() const{return tid_;}
    const std::string& name(){return name_;}

    static int numCreateThread(){return numCreateThread_;}

private:
    bool started_;
    bool joined_;
    std::shared_ptr<std::thread> thread_;
    pid_t tid_;
    ThreadFunc func_;
    std::string name_;
    static std::atomic_int numCreateThread_;

    void setDefaultName();
};

#include "thread.hpp"
#include "currenthread.hpp"

#include <semaphore.h>

Thread::Thread(ThreadFunc func,const std::string &name)
    :started_(false),
    joined_(false),
    tid_(0),
    func_(std::move(func)),
    name_(name)
{
    setDefaultName();
}

Thread::~Thread(){
    if(started_ && !joined_){
        thread_->detach();  //thread有带设置分离方法
    }
}

//一个thread对象记录一个线程的详细信息
void Thread::start(){
    started_ = true;
    sem_t sem;
    sem_init(&sem,false,0);

    //开启线程
    thread_ = std::shared_ptr<std::thread>(new std::thread([&](){
        tid_ = CurrentThread::tid(); //获取线程tid
        sem_post(&sem);
        func_();    //线程任务
    }));

    //这里等待新线程id
    sem_wait(&sem);     //线程执行过快，防止在线程创建完成之前函数就返回了
}

void Thread::join(){
    joined_ = true;
    thread_->join();
}

void Thread::setDefaultName(){
    int num = ++numCreateThread_;
    if(name_.empty()){
        char buf[32] = {0};
        snprintf(buf,sizeof buf,"Thread%d",num);
        name_ = buf;
    }
}

---

EventLoopThread

#pragma once

#include "nocopyable.hpp"
#include "thread.hpp"

#include<functional>
#include<mutex>
#include<condition_variable>

class EventLoop;

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

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

    EventLoop* startloop();

private:
    void threadFunc();
  
    EventLoop* loop_;
    bool exciting_;
    Thread thread_;
    std::mutex mutex_;
    std::condition_variable cond_;
    ThreadInitCallback callback_;

};

#include "eventloopthread.hpp"
#include "eventloop.hpp"

EventLoopThread::EventLoopThread(const ThreadInitCallback &cb, const std::string &name)
    :loop_(nullptr),exciting_(false),thread_(std::bind(&EventLoopThread::threadFunc,this),name),
    mutex_(),cond_(),callback_(cb) 
{

}

EventLoopThread::~EventLoopThread(){
    exciting_ = true;
    if(loop_ != nullptr){
        loop_->quit();
        thread_.join();
    }
}

//每次都是在新线程里执行的
EventLoop* EventLoopThread::startloop(){
    thread_.start();    //启动底层新线程
    EventLoop* loop = nullptr;
    {
        std::unique_lock<std::mutex> lock(mutex_);
        while(loop == nullptr){
            cond_.wait(lock);
        }
        loop = loop_;
    }
    return loop;
}   

void EventLoopThread::threadFunc(){
    EventLoop loop; //创建一个独立的EventLoop

    if(callback_){
        callback_(&loop);
    }

    {
        std::unique_lock<std::mutex> lock(mutex_);
        loop_ = &loop;
        cond_.notify_one();
    }

    loop.loop();    // poller.poll

    std::unique_lock<std::mutex> lock(mutex_);
    loop_ = nullptr;
}

---

EventLoopThreadPool

#pragma once

#include "nocopyable.hpp"   

#include <functional>
#include <string>
#include <vector>
#include <memory>

class EventLoop;
class EventLoopThread;

class EventLoopThreadPool:public nocpoyable{

public:
    using ThreadInitCallback = std::function<void(EventLoop*)>;

    EventLoopThreadPool(EventLoop *baseloop,const std::string &nameArg);
    ~EventLoopThreadPool();

    void setThreadNum(int numThread){
        numCreateThread_ = numThread;
    }

    void start(const ThreadInitCallback &cb = ThreadInitCallback());

    //如果工作在多线程中，baseloop会默认以轮询的方式分配channel给subloop
    EventLoop* GetNextLoop();

    std::vector<EventLoop*> getAllLoops();

    bool started() const{return started_;}
    const std::string name(){return name_;}

private:

    EventLoop* baseloop_;
    std::string name_;
    bool started_;
    int numCreateThread_;
    int next_;
    std::vector<std::unique_ptr<EventLoopThread>> thread_;
    std::vector<EventLoop*> loops_;

};

#include "eventloopthreadpool.hpp"
#include "eventloopthread.hpp"

EventLoopThreadPool::EventLoopThreadPool(EventLoop *baseloop, const std::string &nameArg)
    :baseloop_(baseloop),name_(nameArg),started_(false),numCreateThread_(0),next_(0)
{

}

EventLoopThreadPool::~EventLoopThreadPool()
{
}

void EventLoopThreadPool::start(const ThreadInitCallback &cb = ThreadInitCallback()){
    started_ = true;
    for(int i = 0;i<numCreateThread_;++i){
        char buf[name_.size()+32];
        snprintf(buf,sizeof buf,"%s%d",name_.c_str(),i);

        EventLoopThread* t = new EventLoopThread(cb,buf);
        thread_.push_back(std::unique_ptr<EventLoopThread>(t));
        loops_.push_back(t->startloop());   //创建线程，绑定一个新的EventLoop，并返回该loop地址
    }

    if(numCreateThread_ == 0 && cb){    //只有一条默认线程
        cb(baseloop_);
    }
}

//如果工作在多线程中，baseloop会默认以轮询的方式分配channel给subloop
EventLoop *EventLoopThreadPool::GetNextLoop(){
    EventLoop* loop = baseloop_;

    if(!loops_.empty()){
        loop = loops_[next_];
        ++next_;

        if(next_ >= loops_.size()){
            next_ = 0;
        }
    }
    return loop;
}

std::vector<EventLoop *> EventLoopThreadPool::getAllLoops(){
    if(loops_.empty()){
        return std::vector<EventLoop*>(1,baseloop_);
    }
    else{
        return loops_;
    }
}