生产者消费者问题（C++实现）

#include <windows.h>
#include <iostream>
#include<cstdio>
const unsigned short SIZE_OF_BUFFER = 10; ///缓冲区长度
unsigned short ProductID = 0; ///产品号
unsigned short ConsumeID = 0; ///将被消耗的产品号
unsigned short in = 0; ///产品进缓冲区时的缓冲区下标
unsigned short out = 0; ///产品出缓冲区时的缓冲区下标
int g_buffer[SIZE_OF_BUFFER]; ///缓冲区是个循环队列
bool g_continue = true; ///控制程序结束
HANDLE g_hMutex; ///用于线程间的互斥
HANDLE g_hFullSemaphore; ///当缓冲区满时迫使生产者等待
HANDLE g_hEmptySemaphore; ///当缓冲区空时迫使消费者等待
DWORD WINAPI Producer(LPVOID); ///生产者线程
DWORD WINAPI Consumer(LPVOID); ///消费者线程
int main()
{
    int i;
///创建各个互斥信号
g_hMutex = CreateMutex(NULL,FALSE,NULL);
g_hFullSemaphore = CreateSemaphore(NULL,SIZE_OF_BUFFER-1,SIZE_OF_BUFFER-1,NULL);
g_hEmptySemaphore = CreateSemaphore(NULL,0,SIZE_OF_BUFFER-1,NULL);
///调整下面的数值，可以发现，当生产者个数多于消费者个数时，
///生产速度快，生产者经常等待消费者；反之，消费者经常等待
const unsigned short PRODUCERS_COUNT = 3; ///生产者的个数
const unsigned short CONSUMERS_COUNT = 1; ///消费者的个数
///总的线程数
const unsigned short THREADS_COUNT = PRODUCERS_COUNT+CONSUMERS_COUNT;
HANDLE hThreads[PRODUCERS_COUNT]; ///各线程的handle
DWORD producerID[CONSUMERS_COUNT]; ///生产者线程的标识符
DWORD consumerID[THREADS_COUNT]; ///消费者线程的标识符
///创建生产者线程
for (i=0;i<PRODUCERS_COUNT;++i){
hThreads[i]=CreateThread(NULL,0,Producer,NULL,0,&producerID[i]);
if (hThreads[i]==NULL) return -1;
}
///创建消费者线程
for (i=0;i<CONSUMERS_COUNT;++i){
hThreads[PRODUCERS_COUNT+i]=CreateThread(NULL,0,Consumer,NULL,0,&consumerID[i]);
if (hThreads[i]==NULL) return -1;
}
while(g_continue){
if(getchar()){ ///按回车后终止程序运行
g_continue = false;
}
}
return 0;
}
///生产一个产品。简单模拟了一下，仅输出新产品的ID号
void Produce()
{
std::cerr << "Producing " << ++ProductID << " ... ";
std::cerr << "Succeed" << std::endl;
}
///把新生产的产品放入缓冲区
void Append()
{
std::cerr << "Appending a product ... ";
g_buffer[in] = ProductID;
in = (in+1)%SIZE_OF_BUFFER;
std::cerr << "Succeed" << std::endl;
///输出缓冲区当前的状态
for (int i=0;i<SIZE_OF_BUFFER;++i){
std::cout << i <<": " << g_buffer[i];
if (i==in) std::cout << " <-- 生产";
if (i==out) std::cout << " <-- 消费";
std::cout << std::endl;
}
}
//从缓冲区中取出一个产品
void Take()
{
std::cerr << "Taking a product ... ";
ConsumeID = g_buffer[out];
out = (out+1)%SIZE_OF_BUFFER;
std::cerr << "Succeed" << std::endl;
//输出缓冲区当前的状态
for (int i=0;i<SIZE_OF_BUFFER;++i){
std::cout << i <<": " << g_buffer[i];
if (i==in) std::cout << " <-- 生产";
if (i==out) std::cout << " <-- 消费";
std::cout << std::endl;
}
}
//消耗一个产品
void Consume()
{
std::cerr << "Consuming " << ConsumeID << " ... ";
std::cerr << "Succeed" << std::endl;
}
//生产者
DWORD WINAPI Producer(LPVOID lpPara)
{
while(g_continue){
WaitForSingleObject(g_hFullSemaphore,INFINITE);
WaitForSingleObject(g_hMutex,INFINITE);
Produce();
Append();
Sleep(1500);
ReleaseMutex(g_hMutex);
ReleaseSemaphore(g_hEmptySemaphore,1,NULL);
}
return 0;
}
//消费者
DWORD WINAPI Consumer(LPVOID lpPara)
{
while(g_continue){
WaitForSingleObject(g_hEmptySemaphore,INFINITE);
WaitForSingleObject(g_hMutex,INFINITE);
Take();
Consume();
Sleep(1500);
ReleaseMutex(g_hMutex);
ReleaseSemaphore(g_hFullSemaphore,1,NULL);
}
return 0;
}