操作系统里的生产者、消费者问题

#include <stdlib.h>
#include <iostream>
#include <windows.h>
#include <string>
#include <ctime>
using namespace std;
#define BUFFER_NUM 6

int product[BUFFER_NUM][2];
HANDLE g_semBuffer,g_semProduct,g_mutex;

//   消费者线程
DWORD WINAPI Consumer(LPVOID para)
{
while(1)
{
srand((unsigned)time(NULL));
Sleep(rand()%1000+1000);
WaitForSingleObject(g_semProduct,INFINITE);//等商品区是否有商品,如果有，减1
WaitForSingleObject(g_mutex,INFINITE);//获取对互斥资源的操作权限
int index;
for (index = 0; index < BUFFER_NUM; index ++)
{
if (product[index][1] != 0)//找到了这个位置的商品没有被购买 于是跳出购买
break;
}
cout<<"消费者购买了商品"<<product[index][0]<<endl;
product[index][1] = 0;//购买后将购买标志置0，表示这个位置没有商品了  可以放生产的商品
ReleaseMutex(g_mutex);
ReleaseSemaphore(g_semBuffer,1,NULL);//空闲区位置加1
}
return 0;
}

//   生产者线程
DWORD WINAPI Producer(LPVOID para)
{
while(1)
{
srand((unsigned)time(NULL));
Sleep(rand()%1000 + 2000);
int data = rand()%30;//生产的商品  用数字代表
WaitForSingleObject(g_semBuffer,INFINITE);//等有空闲的位置,空闲区位置减1
WaitForSingleObject(g_mutex,INFINITE);//等对互斥资源的操作权限
int ix;
for (ix = 0; ix < BUFFER_NUM; ix ++)
{
if (product[ix][1] == 0)//找到一个可以放商品的位置
break;
}
product[ix][0] = data;//把生产出的商品放到找到的位置
product[ix][1] = 1;//标识这个位置上有商品
cout<<"        生产者生产了商品"<<data<<endl;
ReleaseMutex(g_mutex);//释放权限
ReleaseSemaphore(g_semProduct,1,NULL);//商品区数量加1
}
return 0;
}

int main()
{
cout<<endl<<"***********输出间隔不等，请耐心等待不要关闭!***********"<<endl<<endl;
for (int i = 0; i < BUFFER_NUM; i ++)
product[i][0] = i + 1;

for (int j = 0; j < BUFFER_NUM; j ++)
product[j][1] = 1;   //初始时每个位子都有商品  因此 一开始肯定消费商品

g_mutex = CreateMutex(NULL,FALSE,NULL);
g_semBuffer = CreateSemaphore(NULL,0,BUFFER_NUM,NULL);//初始时空闲区最少  为0
g_semProduct = CreateSemaphore(NULL,BUFFER_NUM,BUFFER_NUM,NULL);//商品区最大  为BUFFER_NUM

if(!g_semBuffer||!g_mutex)
{
cout<<"Create Semaphore Error!\n";
return -1;
}
HANDLE h[2];
DWORD consumerID,productID;
h[0] = ::CreateThread(NULL,0,Consumer,NULL,0,&consumerID);
h[1] = ::CreateThread(NULL,0,Producer,NULL,0,&productID);
WaitForMultipleObjects(2,h,TRUE,INFINITE);
::CloseHandle(h[0]);
::CloseHandle(h[1]);
return 0;
}