生产消费模型-简洁线程池

本文章没有知识讲解，只有代码：

#pragma once
#include <iostream>
#include <vector>
#include <queue>
#include <pthread.h>
#include <unistd.h>

#include "Task.hpp"

// 创建固定数量的线程池，循环从任务队列中获取任务队列
// 获取到任务后，执行任务对象中的任务接口

class ThreadInfo
{
    // public:
    //     ThreadInfo(std::string thradname="")
    //         :_threadname(_threadname)
    //     {}
public:
    std::string _threadname;
    pthread_t tid;
};

static const int defaultNum = 10;

template <class T>
class ThreadPool
{
private:
    ThreadPool(int num = defaultNum)
        : _threads(num)
    {
        printf("num:%d\n", num);

        //如果成员变量使用的是指针的形式
        // _mutex=new pthread_mutex_t;
        // _cond=new pthread_cond_t;

        pthread_mutex_init(&_mutex, nullptr);
        pthread_cond_init(&_cond, nullptr);
    }

    ~ThreadPool()
    {
        pthread_mutex_destroy(&_mutex);
        pthread_cond_destroy(&_cond);
        
        //如果成员变量使用的是指针的形式
        // delete _mutex;
        // delete _cond;
    }
    ThreadPool(const ThreadPool<T> &) = delete;
    const ThreadPool<T> &operator=(const ThreadPool<T> &) = delete;

public:
    void Lock()
    {
        pthread_mutex_lock(&_mutex);
    }
    void Unlock()
    {
        pthread_mutex_unlock(&_mutex);
    }

    void WakeuP()
    {
        pthread_cond_signal(&_cond);
    }

    void ThreadSleep()
    {
        pthread_cond_wait(&_cond, &_mutex);
    }

    bool QueueIsEmpty()
    {
        return _task.empty();
    }

    std::string GetThreadName(pthread_t tid)
    {
        for (auto &t : _threads)
        {
            if (t.tid == tid)
                return t._threadname;
        }
        return "None";
    }

public:
    static void *Handlder(void *args)
    {
        ThreadPool<T> *tp = static_cast<ThreadPool<T> *>(args);
        std::string Threadname = tp->GetThreadName(pthread_self());
        // std::cout<<"Handlder"<<std::endl;
        while (true)
        {
            tp->Lock();
            while (tp->QueueIsEmpty())
            {
                tp->ThreadSleep();
            }
            tp->Unlock();
            T t = tp->Pop();
            t();
            sleep(1);
            std::cout << Threadname << ":run" << t.GetResult() << std::endl;
        }
        return nullptr;
    }
    void Start()
    {
        std::cout << "Handlder" << std::endl;

        int num = _threads.size();
        // printf("num:%d\n",num);
        for (int i = 0; i < num; i++)
        {
            _threads[i]._threadname = "thread-" + std::to_string(i + 1);
            // std::cout<<"create before"<<std::endl;

            pthread_create(&(_threads[i].tid), nullptr, Handlder, this);
        }
    }

    void Push(const T &t)
    {
        Lock();
        _task.push(t);
        WakeuP();
        Unlock();
    }

    T Pop()
    {
        T out = _task.front();
        _task.pop();
        return out;
    }
    
    //单例模式接口
    static ThreadPool<T> *GetInstance()
    {
        if (tp == nullptr)
        {
            pthread_mutex_lock(&_lock);
            if (tp == nullptr)
            {
                std::cout << "log:singleton create done first" << std::endl;
                tp = new ThreadPool<T>();
            }
            pthread_mutex_unlock(&_lock);
        }
        return tp;
    }

private:
    std::vector<ThreadInfo> _threads;
    std::queue<T> _task;
    // 锁
    pthread_mutex_t _mutex;
    // 条件变量
    pthread_cond_t _cond;
    static ThreadPool<T> *tp;
    static pthread_mutex_t _lock;
};

template <class T>
ThreadPool<T> *ThreadPool<T>::tp = nullptr;

template <class T>
pthread_mutex_t ThreadPool<T>::_lock = PTHREAD_MUTEX_INITIALIZER;

#pragma once
#include <iostream>

static const std::string ops = "+-*/%";
enum
{
    DIV_ZERO = 1,
    MOD_ZERO,
    UNKONW,
};
class Task
{
public:
    Task()
    {
    }

    Task(int x, int y, char op)
        : x_(x), y_(y), op_(op), exitcode_(0), result_(0)
    {
    }

    void run()
    {
        switch (op_)
        {
        case '+':
            result_ = x_ + y_;
            break;
        case '-':
            result_ = x_ - y_;
            break;
        case '*':
            result_ = x_ * y_;
        case '/':
        {
            if (y_ == 0)
                exitcode_ = DIV_ZERO;
            else
                result_ = x_ / y_;
            break;
        }

        case '%':
        {
            if (y_ == 0)
                exitcode_ = MOD_ZERO;
            else
                result_ = x_ % y_;
            break;
        }
        default:
            exitcode_ = UNKONW;
            break;
        }
    }

    void operator()()
    {
        run();
    }

    std::string GetResult()
    {
        std::string ret = "x";
        ret += op_;
        ret += "y=";
        ret += std::to_string(result_);
        ret += ",exitcode:";
        ret += std::to_string(exitcode_);
        return ret;
    }
    std::string GetTask()
    {
        std::string r = std::to_string(x_);
        r += op_;
        r += std::to_string(y_);
        r += "=?";
        return r;
    }
    ~Task()
    {
    }

private:
    int x_;
    int y_;
    char op_;
    int result_;
    int exitcode_;
};

#include"ThreadPool.hpp"

int main()
{
    // ThreadPool<Task>* t=new ThreadPool<Task>();
    
    // std::cout<<"init done"<<std::endl;
    
    // t->Start();
    ThreadPool<Task>::GetInstance()->Start();
    srand(time(nullptr));
    while(true)
    {
        //构建任务
        int x=rand()%20+1;
        sleep(1);
        int y=rand()%10;
        char op=ops[rand()%ops.size()];
        Task t(x,y,op);
        ThreadPool<Task>::GetInstance()->Push(t);
        //交给线程池处理
        std::cout<<"main thread make task: "<<t.GetTask()<<std::endl;
    }
    return 0;
}

代码结果：

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