Windows 多线程（七） 生产者和消费者

本文参考：http://blog.csdn.net/morewindows/article/details/7577591

首先来简化问题，先假设生产者和消费者都只有一个，且缓冲区也只有一个。这样情况就简便多了。

    第一．从缓冲区取出产品和向缓冲区投放产品必须是互斥进行的。可以用关键段和互斥量来完成。

    第二．生产者要等待缓冲区为空，这样才可以投放产品，消费者要等待缓冲区不为空，这样才可以取出产品进行消费。并且由于有二个等待过程，所以要用二个事件或信号量来控制。

#include "stdio.h"#include "process.h"#include "windows.h"//一个生产者，一个消费者，一个缓冲区//设置控制台输出颜色BOOL SetConsoleColor(WORD wAttributes){HANDLE hConsole =GetStdHandle(STD_OUTPUT_HANDLE);if(hConsole ==INVALID_HANDLE_VALUE){return FALSE;}returnSetConsoleTextAttribute(hConsole,wAttributes);}const int END_PRODUCE_NUMBER =10;int g_Buffer;//事件与关键段CRITICAL_SECTION g_cs;HANDLE g_hEventBufferEmpty,g_hEventBufferFull;//生产者线程函数unsigned int __stdcall ProducerThreadFun(PVOID pM){for (int i=1;i<=END_PRODUCE_NUMBER;i++){//等待缓冲区为空WaitForSingleObject(g_hEventBufferEmpty,INFINITE);//互斥的访问缓冲区EnterCriticalSection(&g_cs);g_Buffer =i;printf("生产者将数据%d放入缓冲区\n",g_Buffer);LeaveCriticalSection(&g_cs);//通知缓冲区有新数据了SetEvent(g_hEventBufferFull);}return 0;}//消费者线程函数unsigned int __stdcall ConsumerThreadFun(PVOID){volatile bool flag =true;while (flag){//等待缓冲区中有数据WaitForSingleObject(g_hEventBufferFull,INFINITE);//互斥的访问缓冲区EnterCriticalSection(&g_cs);SetConsoleColor(FOREGROUND_GREEN);printf("  消费者从缓冲区中去数据%d\n",g_Buffer);SetConsoleColor(FOREGROUND_RED|FOREGROUND_GREEN|FOREGROUND_BLUE);if(g_Buffer ==END_PRODUCE_NUMBER)flag =false;LeaveCriticalSection(&g_cs);//通知缓冲区为空SetEvent(g_hEventBufferEmpty);Sleep(10);}return 0;}int main(){printf(" 生产者消费者问题   1生产者 1消费者 1缓冲区\n");InitializeCriticalSection(&g_cs);//创建二个自动复位事件，一个表示缓冲区是否为空，另一个表示缓冲区是否已经处理g_hEventBufferEmpty =CreateEvent(NULL,FALSE,TRUE,NULL);g_hEventBufferFull =CreateEvent(NULL,FALSE,FALSE,NULL);const int THREADNUM =2;HANDLE hThread[THREADNUM];hThread[0] =(HANDLE)_beginthreadex(NULL,0,ProducerThreadFun,NULL,0,NULL);hThread[1] =(HANDLE)_beginthreadex(NULL,0,ConsumerThreadFun,NULL,0,NULL);WaitForMultipleObjects(THREADNUM,hThread,TRUE,INFINITE);CloseHandle(hThread[0]);CloseHandle(hThread[1]);//销毁事件和关键段CloseHandle(g_hEventBufferEmpty);CloseHandle(g_hEventBufferFull);DeleteCriticalSection(&g_cs);return 0;}

然后再对这个简单生产者消费者问题加大难度。将消费者改成2个，缓冲池改成拥有4个缓冲区的大缓冲池。

//1生产者 2消费者 4缓冲区  #include <stdio.h>  #include <process.h>  #include <windows.h>  //设置控制台输出颜色  BOOL SetConsoleColor(WORD wAttributes)  {  HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);  if (hConsole == INVALID_HANDLE_VALUE)  return FALSE;  return SetConsoleTextAttribute(hConsole, wAttributes);  }  const int END_PRODUCE_NUMBER = 8;  //生产产品个数  const int BUFFER_SIZE = 4;          //缓冲区个数  int g_Buffer[BUFFER_SIZE];          //缓冲池  int g_i, g_j;  //信号量与关键段  CRITICAL_SECTION g_cs;  HANDLE g_hSemaphoreBufferEmpty, g_hSemaphoreBufferFull;  //生产者线程函数  unsigned int __stdcall ProducerThreadFun(PVOID pM)  {  for (int i = 1; i <= END_PRODUCE_NUMBER; i++)  {  //等待有空的缓冲区出现  WaitForSingleObject(g_hSemaphoreBufferEmpty, INFINITE);  //互斥的访问缓冲区  EnterCriticalSection(&g_cs);  g_Buffer[g_i] = i;  printf("生产者在缓冲池第%d个缓冲区中投放数据%d\n", g_i, g_Buffer[g_i]);  g_i = (g_i + 1) % BUFFER_SIZE;  LeaveCriticalSection(&g_cs);  //通知消费者有新数据了  ReleaseSemaphore(g_hSemaphoreBufferFull, 1, NULL);  }  printf("生产者完成任务，线程结束运行\n");  return 0;  }  //消费者线程函数  unsigned int __stdcall ConsumerThreadFun(PVOID pM)  {  while (true)  {  //等待非空的缓冲区出现  WaitForSingleObject(g_hSemaphoreBufferFull, INFINITE);  //互斥的访问缓冲区  EnterCriticalSection(&g_cs);  SetConsoleColor(FOREGROUND_GREEN);  printf("  编号为%d的消费者从缓冲池中第%d个缓冲区取出数据%d\n", GetCurrentThreadId(), g_j, g_Buffer[g_j]);  SetConsoleColor(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);  if (g_Buffer[g_j] == END_PRODUCE_NUMBER)//结束标志  {  LeaveCriticalSection(&g_cs);  //通知其它消费者有新数据了(结束标志)  ReleaseSemaphore(g_hSemaphoreBufferFull, 1, NULL);  break;  }  g_j = (g_j + 1) % BUFFER_SIZE;  LeaveCriticalSection(&g_cs);  Sleep(50); //some other work to do  ReleaseSemaphore(g_hSemaphoreBufferEmpty, 1, NULL);  }  SetConsoleColor(FOREGROUND_GREEN);  printf("  编号为%d的消费者收到通知，线程结束运行\n", GetCurrentThreadId());  SetConsoleColor(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);  return 0;  }  int main()  {  printf("  生产者消费者问题   1生产者 2消费者 4缓冲区\n");  InitializeCriticalSection(&g_cs);  //初始化信号量,一个记录有产品的缓冲区个数,另一个记录空缓冲区个数.  g_hSemaphoreBufferEmpty = CreateSemaphore(NULL, 4, 4, NULL);  g_hSemaphoreBufferFull  = CreateSemaphore(NULL, 0, 4, NULL);  g_i = 0;  g_j = 0;  memset(g_Buffer, 0, sizeof(g_Buffer));  const int THREADNUM = 3;  HANDLE hThread[THREADNUM];  //生产者线程  hThread[0] = (HANDLE)_beginthreadex(NULL, 0, ProducerThreadFun, NULL, 0, NULL);  //消费者线程  hThread[1] = (HANDLE)_beginthreadex(NULL, 0, ConsumerThreadFun, NULL, 0, NULL);  hThread[2] = (HANDLE)_beginthreadex(NULL, 0, ConsumerThreadFun, NULL, 0, NULL);  WaitForMultipleObjects(THREADNUM, hThread, TRUE, INFINITE);  for (int i = 0; i < THREADNUM; i++)  CloseHandle(hThread[i]);  //销毁信号量和关键段  CloseHandle(g_hSemaphoreBufferEmpty);  CloseHandle(g_hSemaphoreBufferFull);  DeleteCriticalSection(&g_cs);  return 0;  }