c实现生产者消费者问题。 windows下。

#include <stdio.h>
#include <windows.h>

#define P(S) WaitForSingleObject(S,INFINITE)//定义Windows下的P操作
#define V(S) ReleaseSemaphore(S,1,NULL)//定义Windows下的V操作

//生产者 消费者 缓冲区
#define num_of_productors 2
#define num_of_consumers 3
#define num_of_buffers 3

int nextp = 1; //下一个产品的编号
int in = 0, out = 0; //分别指向下一个存放产品和取出产品的缓冲区编号
int g_Buffer[num_of_buffers] = { 0 }; //缓冲区初始值为空

HANDLE g_hSemaphoreEmpty, g_hSemaphoreFull, g_hMutex;

//生产者线程函数
DWORD WINAPI ProducerThreadFun(LPVOID pM)
{
Sleep(100);
do{
int id = *((int*)(pM)); //生产者编号
P(g_hSemaphoreEmpty);
P(g_hMutex);
g_Buffer[in] = nextp;
printf("生产者%d将数据%d放入缓冲区%d\n", id, nextp, in);
nextp++;
in = (in + 1) % num_of_buffers;
V(g_hMutex);
V(g_hSemaphoreFull);
Sleep(100);
if (nextp > 12) break;
} while(true);
return 0;
}
//消费者线程函数
DWORD WINAPI ConsumerThreadFun(LPVOID pM)
{
Sleep(100);
do
{
int id = *((int*)(pM)); //消费者编号
P(g_hSemaphoreFull);
P(g_hMutex);
//nextp = g_Buffer[out];
printf(" 消费者%d从缓冲区%d中取数据%d\n", id, out, g_Buffer[out]);
out = (out + 1) % num_of_buffers;
V(g_hMutex);
V(g_hSemaphoreEmpty);
Sleep(100);
} while (true);
}
int main()
{
int num[num_of_productors + num_of_consumers];
printf(" 生产者消费者问题:%d生产者 %d消费者 %d缓冲区\n", num_of_productors, num_of_consumers, num_of_buffers);
//初始值为num_of_buffers的信号量
g_hSemaphoreEmpty = CreateSemaphore(NULL, num_of_buffers, num_of_buffers, NULL); //继承/初始化信号计数/最大信号计数/名称
//初始值为0的信号量
g_hSemaphoreFull = CreateSemaphore(NULL, 0, num_of_buffers, NULL);
//互斥量
g_hMutex = CreateSemaphore(NULL, 1, 1, NULL);

const int THREADNUM = num_of_productors + num_of_consumers; //线程数
HANDLE hThread[THREADNUM];

for (int i = 0; i < num_of_productors; i++) //创建生产者线程
{
num[i] = i + 1;
hThread[i] = CreateThread(NULL, 0, ProducerThreadFun, (LPVOID *)&num[i], 0, NULL);
} //继承/初始栈大小/线程函数/向线程函数传递的参数/线程标志 0 表示创建后立即激活/保存新线程的ID
for (int i = num_of_productors; i < num_of_productors + num_of_consumers; i++) //创建消费者者线程
{
num[i] = i - num_of_productors + 1;
hThread[i] = CreateThread(NULL, 0, ConsumerThreadFun, (LPVOID *)&num[i], 0, NULL);
}

WaitForMultipleObjects(THREADNUM, hThread, TRUE, INFINITE);

system("pause");
return 0;
}