多執行緒實現生產者與消費者

#pragma once
#include <iostream>
#include <mutex>
#include <thread>
#include <condition_variable>

 class ProAndConClass
{
public:
    ProAndConClass();
    ~ProAndConClass();
    void printThread();
    void addThread(int num);
    bool g_flag = false;
    ProAndConClass
 
* getInstance()
    {
        return &instance;
    }
private:
    static ProAndConClass instance;
    std::condition_variable g_cond_add_enable; //計算條件變數
    std::condition_variable g_cond_print_enable;//列印條件
    std::mutex g_mutex;
    int g_value = 0;
    bool g_print_able = false; //是否可以列印
};
 

//.cpp檔案
 

#include "ProduceAndConsume.h"
 
//若不在堆上建立類的例項。
//需要定義在全域性區,不能放在類的內部，類成員變數可能分配在堆或者棧上
//執行緒是不會共享棧區的
//std::condition_variable g_cond_add_enable; //計算條件變數
//std::condition_variable g_cond_print_enable;//列印條件
//std::mutex g_mutex;
//int g_value = 0;
//bool g_print_able = false; //是否可以列印

ProAndConClass::ProAndConClass()
{
}
ProAndConClass::
 
~ProAndConClass()
{
}
void ProAndConClass::addThread(int numThread)
{
    std::cout << "add thread begin" << std::endl;
    while (g_value < numThread)
    {
        std::unique_lock<std::mutex>my_lock(g_mutex);
        g_cond_add_enable.wait(my_lock,
            [=] {
            return !g_print_able;
        });
        g_value++;
        g_print_able = true;
        std::cout << "++add thread" << g_value << std::endl;
        g_cond_print_enable.notify_one(); //增加列印
    }
    //g_flag = false;
    std::cout << "add thread leave"<<std::endl;
}

void ProAndConClass::printThread()
{
    std::cout << "print thread begin" << std::endl;
    while (g_flag)
    {
        std::unique_lock<std::mutex> my_lock(g_mutex);
        g_cond_print_enable.wait(my_lock,
            [=] {
            return g_print_able;
        });
        g_print_able = false;
        std::cout << "-- print thread" << g_value << std::endl;
        g_cond_add_enable.notify_one();//通知增加執行緒
    }
    std::cout << "print thread leave" << std::endl;
}

//main
void testProAndCon()
{
  ProAndConClass*proandcon=new(std::nothrow)ProAndConClass();
     proandcon->g_flag = true;
    /*ProAndConClass proandcon;//如此,需要把變數定義到全域性資料段.因為這種形式物件構造在棧區，而執行緒獨享棧區
    proandcon.g_flag = true;*/
    //執行緒的初始化三種方式：普通函式、類成員函式、函式物件
    std::thread thread_add(&ProAndConClass::addThread, proandcon, 10); // 生產者
    std::thread thread_print(&ProAndConClass::printThread, proandcon); //消費者
    //getchar();
    Sleep(1000);

    if (thread_add.joinable())
    {
        std::cout << "join add thread" << std::endl;
        thread_add.join();
    }
    if (thread_print.joinable())
    {
        std::cout << "join print thread" << std::endl;
        thread_print.join();
    }
    return;
}