VC多线程信号量的应用

本文参考以下文章并做了扩展，加深信号量的理解

http://blog.youkuaiyun.com/morewindows/article/details/7577591

//2生产者 8消费者 4缓冲区 5最大信号量
#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 = 20;  //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_iNumber;
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)
{
 while(1)
 {
  //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);
  //InterlockedIncrement((long*)&g_Buffer[g_i]) ;
  if (g_iNumber==END_PRODUCE_NUMBER)
  {
   LeaveCriticalSection(&g_cs);
   break;
  }
  
  g_iNumber++;
  g_Buffer[g_i]=g_iNumber;
  printf("生产者在缓冲池第%d个缓冲区中投放数据%d\n", g_i, g_iNumber);
  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_hSemaphoreBufferEmpty, 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");
 printf(" -- by MoreWindows( http://blog.youkuaiyun.com/MoreWindows ) --\n\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, 5, 5, NULL);
 g_hSemaphoreBufferFull  = CreateSemaphore(NULL, 0, 5, NULL);
 g_i = 0;
 g_j = 0;
 g_iNumber=0;
 memset(g_Buffer, 0, sizeof(g_Buffer));

 const int THREADNUM = 10;
 HANDLE hThread[THREADNUM];
 //生产者线程
 hThread[0] = (HANDLE)_beginthreadex(NULL, 0, ProducerThreadFun, NULL, 0, NULL);
 hThread[1] = (HANDLE)_beginthreadex(NULL, 0, ProducerThreadFun, NULL, 0, NULL);
 //消费者线程
 for (int i=0;i<8;i++)
 {
  hThread[2+i] = (HANDLE)_beginthreadex(NULL, 0, ConsumerThreadFun, NULL, 0, NULL);
 }
 
// hThread[2] = (HANDLE)_beginthreadex(NULL, 0, ConsumerThreadFun, NULL, 0, NULL);
 WaitForMultipleObjects(THREADNUM, hThread, TRUE, INFINITE);
 for ( 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;
}