生产者消费者问题（C++实现）

  1 #include <windows.h>
  2 #include <iostream>
  3 const unsigned short SIZE_OF_BUFFER = 10; //缓冲区长度
  4 unsigned short ProductID = 0; //产品号
  5 unsigned short ConsumeID = 0; //将被消耗的产品号
  6 unsigned short in = 0; //产品进缓冲区时的缓冲区下标
  7 unsigned short out = 0; //产品出缓冲区时的缓冲区下标
  8 int g_buffer[SIZE_OF_BUFFER]; //缓冲区是个循环队列
  9 bool g_continue = true; //控制程序结束
 10 HANDLE g_hMutex; //用于线程间的互斥
 11 HANDLE g_hFullSemaphore; //当缓冲区满时迫使生产者等待
 12 HANDLE g_hEmptySemaphore; //当缓冲区空时迫使消费者等待
 13 DWORD WINAPI Producer(LPVOID); //生产者线程
 14 DWORD WINAPI Consumer(LPVOID); //消费者线程
 15 int main()
 16 {
 17     int i;
 18 //创建各个互斥信号
 19 g_hMutex = CreateMutex(NULL,FALSE,NULL);
 20 g_hFullSemaphore = CreateSemaphore(NULL,SIZE_OF_BUFFER-1,SIZE_OF_BUFFER-1,NULL);
 21 g_hEmptySemaphore = CreateSemaphore(NULL,0,SIZE_OF_BUFFER-1,NULL);
 22 //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，
 23 //生产速度快，生产者经常等待消费者；反之，消费者经常等待
 24 const unsigned short PRODUCERS_COUNT = 3; //生产者的个数
 25 const unsigned short CONSUMERS_COUNT = 1; //消费者的个数
 26 //总的线程数
 27 const unsigned short THREADS_COUNT = PRODUCERS_COUNT+CONSUMERS_COUNT;
 28 HANDLE hThreads[PRODUCERS_COUNT]; //各线程的handle
 29 DWORD producerID[CONSUMERS_COUNT]; //生产者线程的标识符
 30 DWORD consumerID[THREADS_COUNT]; //消费者线程的标识符
 31 //创建生产者线程
 32 for (i=0;i<PRODUCERS_COUNT;++i){
 33 hThreads[i]=CreateThread(NULL,0,Producer,NULL,0,&producerID[i]);
 34 if (hThreads[i]==NULL) return -1;
 35 }
 36 //创建消费者线程
 37 for (i=0;i<CONSUMERS_COUNT;++i){
 38 hThreads[PRODUCERS_COUNT+i]=CreateThread(NULL,0,Consumer,NULL,0,&consumerID[i]);
 39 if (hThreads[i]==NULL) return -1;
 40 }
 41 while(g_continue){
 42 if(getchar()){ //按回车后终止程序运行
 43 g_continue = false;
 44 }
 45 }
 46 return 0;
 47 }
 48 //生产一个产品。简单模拟了一下，仅输出新产品的ID号
 49 void Produce()
 50 {
 51 std::cerr << "Producing " << ++ProductID << " ... ";
 52 std::cerr << "Succeed" << std::endl;
 53 }
 54 //把新生产的产品放入缓冲区
 55 void Append()
 56 {
 57 std::cerr << "Appending a product ... ";
 58 g_buffer[in] = ProductID;
 59 in = (in+1)%SIZE_OF_BUFFER;
 60 std::cerr << "Succeed" << std::endl;
 61 //输出缓冲区当前的状态
 62 for (int i=0;i<SIZE_OF_BUFFER;++i){
 63 std::cout << i <<": " << g_buffer[i];
 64 if (i==in) std::cout << " <-- 生产";
 65 if (i==out) std::cout << " <-- 消费";
 66 std::cout << std::endl;
 67 }
 68 }
 69 //从缓冲区中取出一个产品
 70 void Take()
 71 {
 72 std::cerr << "Taking a product ... ";
 73 ConsumeID = g_buffer[out];
 74 out = (out+1)%SIZE_OF_BUFFER;
 75 std::cerr << "Succeed" << std::endl;
 76 //输出缓冲区当前的状态
 77 for (int i=0;i<SIZE_OF_BUFFER;++i){
 78 std::cout << i <<": " << g_buffer[i];
 79 if (i==in) std::cout << " <-- 生产";
 80 if (i==out) std::cout << " <-- 消费";
 81 std::cout << std::endl;
 82 }
 83 }
 84 //消耗一个产品
 85 void Consume()
 86 {
 87 std::cerr << "Consuming " << ConsumeID << " ... ";
 88 std::cerr << "Succeed" << std::endl;
 89 }
 90 //生产者
 91 DWORD WINAPI Producer(LPVOID lpPara)
 92 {
 93 while(g_continue){
 94 WaitForSingleObject(g_hFullSemaphore,INFINITE);
 95 WaitForSingleObject(g_hMutex,INFINITE);
 96 Produce();
 97 Append();
 98 Sleep(1500);
 99 ReleaseMutex(g_hMutex);
100 ReleaseSemaphore(g_hEmptySemaphore,1,NULL);
101 }
102 return 0;
103 }
104 //消费者
105 DWORD WINAPI Consumer(LPVOID lpPara)
106 {
107 while(g_continue){
108 WaitForSingleObject(g_hEmptySemaphore,INFINITE);
109 WaitForSingleObject(g_hMutex,INFINITE);
110 Take();
111 Consume();
112 Sleep(1500);
113 ReleaseMutex(g_hMutex);
114 ReleaseSemaphore(g_hFullSemaphore,1,NULL);
115 }
116 return 0;
117 }