2023-12-28 muduo库学习之仿写代码8 Thread类实现

Thread.h

这个Thread就只是一个线程，跟下一篇的EventLoopThread是不同的

#pragma once

#include "noncopyable.h"

#include <functional>
#include <thread>
#include <memory>
#include <string>
#include <atomic>

class Thread : noncopyable{
public:
    using ThreadFunc = std::function<void()>;

    explicit Thread(ThreadFunc, const std::string &name = std::string());
    ~Thread();

    void start();
    void join();

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

    static int numCreated() {return numCreated_;}
private:
    void setDefaultName();

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

Thread.cc

#include "Thread.h"
#include "CurrentThread.h"

#include <semaphore.h>

std::atomic_int Thread::numCreated_ = {0};

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类提供的设置分离线程的方法
    }
}

void Thread::start(){ //一个Thread对象，记录的就是一个新线程的详细信息
    started_ = true;
    sem_t sem;
    sem_init(&sem, false, 0);
    // 开启线程
    thread_ = std::shared_ptr<std::thread>(new std::thread([&](){
        // 获取线程的tid值
        tid_ = CurrentThread::tid();
        sem_post(&sem);
        // 开启一个新线程， 专门执行该线程函数
        func_(); 
    }));

    // 这里必须等待获取上面新创建的线程的tid值
    sem_wait(&sem);
}

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

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