C++模拟“生产者消费者”进程同步问题

#include <iostream>
#include <cstdlib>
#include <windows.h>
#include <string>
#include <time.h>

using namespace std;

const int limit = 30;  //生产总量
const int maxsize = 10; //缓冲区大小
const int kind = 7;
int bufIdx = 0;    //当前缓冲区下标

string buf[maxsize];    //缓冲区 （字符串）

//伪造的产品
string product[] = {"Apple","Banana","Cherry","Orange","Pear","Peach","WaterMelon"};

HANDLE mutex,full,empty;

HANDLE disp;    //用于控制屏幕打印的互斥锁

//生产者子过程
DWORD WINAPI Producer(LPVOID param)
{
    int ct,idx;
    const int pwait = 100;
    srand(time(NULL)); //随机数播种

    WaitForSingleObject(disp, INFINITE);
    cout << "Producer Start!" << endl << endl;
    ReleaseMutex(disp);

	for (ct = 0; ct < limit; ct ++)
	{
	    idx = rand() % kind;

	    WaitForSingleObject(disp, INFINITE);
	    cout << product[idx] << " is ready!" << endl << endl;
	    ReleaseMutex(disp);

	    WaitForSingleObject(empty, INFINITE); //请求一个空缓冲区，阻塞
	    WaitForSingleObject(mutex, INFINITE); //请求互斥锁，阻塞
	    buf[bufIdx ++] = product[idx];

	    WaitForSingleObject(disp, INFINITE);
        cout << product[idx] << " added to slot No. " << bufIdx << endl << endl;
        ReleaseMutex(disp);

        ReleaseMutex(mutex);    //释放互斥锁
        ReleaseSemaphore (full, 1, NULL);   //signal(full)
        Sleep(rand() % pwait + 100);  //休息一会
	}
	cout << "Producer Quit!" << endl << endl;
	return 0;
}

//消费者子过程
DWORD WINAPI Consumer(LPVOID param)
{
    int ct;
    const int cwait = 300;
    string stuff;
    srand(time(NULL));

    WaitForSingleObject(disp, INFINITE);
    cout << "Consumer Start!" << endl << endl;
    ReleaseMutex(disp);

    for (ct = 0; ct < limit; ct ++)
	{
	    WaitForSingleObject(full, INFINITE); //请求一个满缓冲区，阻塞
	    WaitForSingleObject(mutex, INFINITE); //请求互斥锁，阻塞
	    stuff = buf[-- bufIdx];

        WaitForSingleObject(disp, INFINITE);
        cout << "Consumer get " << stuff << " from slot No. " << (bufIdx + 1) << endl << endl;
        ReleaseMutex(disp);

        ReleaseMutex(mutex);    //释放互斥锁
        ReleaseSemaphore (empty, 1, NULL);   //signal(empty)
        Sleep(rand() % cwait + 100);  //休息一会
	}
	cout << "Consumer Quit!" << endl << endl;
	return 0;
}

int main()
{
    //生产者线程与消费者线程的线程ID
	DWORD ProducerID, ConsumerID;
	//线程句柄
	HANDLE ProducerHandle, ConsumerHandle;

	//创建生产者线程
	ProducerHandle = CreateThread(NULL, 0, Producer, NULL, 0, &ProducerID);
	//创建消费者线程
	ConsumerHandle = CreateThread(NULL, 0, Consumer, NULL, 0, &ConsumerID);

    disp = CreateMutex(NULL, FALSE, NULL);
    //创建互斥锁
    mutex = CreateMutex(NULL, FALSE, NULL);
    //创建缓冲区占用信号量
    full = CreateSemaphore (NULL, 0, maxsize, "full");
    //创建缓冲区空闲信号量
    empty = CreateSemaphore (NULL, maxsize, maxsize, "empty");

    //等待直到生产者线程执行完成
	if (ProducerHandle != NULL)
	{
		WaitForSingleObject(ProducerHandle, INFINITE);
		CloseHandle(ProducerHandle);
	}
    //等待直到消费者线程执行完成
	if (ConsumerHandle != NULL)
	{
		WaitForSingleObject(ConsumerHandle, INFINITE);
		CloseHandle(ConsumerHandle);
	}
	system("pause");
}