多线程练习----生产者消费者

#include<windows.h> #include<iostream> using namespace std;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        CRITICAL_SECTION g_cs;             //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() { //创建各个互斥信号 InitializeCriticalSection( &g_cs); 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; //各线程的handle HANDLE hThreads[PRODUCERS_COUNT];  //创建生产者线程 for(int i = 0; i < PRODUCERS_COUNT; ++i){ hThreads[i] = CreateThread(NULL,0,Producer,NULL,0,NULL); 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,NULL); if (hThreads[i]==NULL)return   -1; } Sleep(100000);DeleteCriticalSection(&g_cs);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() {  cerr << "Producing  " << ++ProductID <<  "   ...   ";  cerr << "Succeed " << endl; } //把新生产的产品放入缓冲区 void   Append() {  cerr << "Appending   a   product   ...   "; g_buffer[in]   =   ProductID; in   =   (in+1) % SIZE_OF_BUFFER;  cerr << "Succeed " << endl; //输出缓冲区当前的状态 for (int i=0; i < SIZE_OF_BUFFER; ++i){ cout << i << ":   " << g_buffer[i]; if(i==in) cout << "   <--   生产 "; if(i==out) cout << "   <--   消费 ";  cout << endl; } } //从缓冲区中取出一个产品 void   Take() { cerr << "Taking   a   product   ...   "; ConsumeID   =   g_buffer[out]; out = (out+1)%SIZE_OF_BUFFER; cerr << "Succeed " << endl; //输出缓冲区当前的状态 for   (int   i=0;i <SIZE_OF_BUFFER;++i){  cout << i << ":   " << g_buffer[i]; if  (i==in)cout << "   <--   生产 "; if  (i==out)cout << "   <--   消费 ";  cout << endl; } } //消耗一个产品 void   Consume() {  cerr  <<   "Consuming   " <<ConsumeID<<"   ...   " <<   "Succeed " <<  endl; } //生产者 DWORD WINAPI Producer(LPVOID lpPara) { while(1){ WaitForSingleObject(g_hFullSemaphore,INFINITE); EnterCriticalSection(&g_cs);Produce(); Append(); Sleep(1500); LeaveCriticalSection(&g_cs);ReleaseSemaphore(g_hEmptySemaphore,1,NULL); } return   0; } //消费者 DWORD WINAPI Consumer(LPVOID lpPara) { while(1){ WaitForSingleObject(g_hEmptySemaphore,INFINITE); EnterCriticalSection(&g_cs);Take(); Consume(); Sleep(1500); LeaveCriticalSection(&g_cs);ReleaseSemaphore(g_hFullSemaphore,1,NULL); } return   0; }