windows多线程－关键代码段(临界区)

来源：互联网发布：牛仔淘宝生产商编辑：程序博客网时间：2024/05/12 15:16

例1 使用关键代码段(临界区)实现线程同步

#include <windows.h>
#include <iostream.h>

DWORD WINAPI Fun1Proc(
LPVOID lpParameter // thread data
);

DWORD WINAPI Fun2Proc(
LPVOID lpParameter // thread data
);

int tickets=100;

CRITICAL_SECTION g_cs;
void main()
{
HANDLE hThread1;
HANDLE hThread2;
hThread1=CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);
hThread2=CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);
CloseHandle(hThread1);
CloseHandle(hThread2);

InitializeCriticalSection(&g_cs);
Sleep(4000);

DeleteCriticalSection(&g_cs);
}

DWORD WINAPI Fun1Proc(
LPVOID lpParameter   // thread data
)
{
while(TRUE)
{
  EnterCriticalSection(&g_cs);
  if(tickets>0)
  {
   Sleep(1);
   cout<<"thread1 sell ticket : "<<tickets--<<endl;
  }
  else
   break;
  LeaveCriticalSection(&g_cs);
}

return 0;
}

DWORD WINAPI Fun2Proc(
LPVOID lpParameter   // thread data
)
{

while(TRUE)
{
  EnterCriticalSection(&g_cs);
  if(tickets>0)
  {
   Sleep(1);
   cout<<"thread2 sell ticket : "<<tickets--<<endl;
  }
  else
   break;
  LeaveCriticalSection(&g_cs);
}
cout<<"thread2 is running!"<<endl;
return 0;
}

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例2 使用关键代码段(临界区)（创建多个临界区对象时）容易产生死锁，比如下面代码：

#include <windows.h>
#include <iostream.h>

DWORD WINAPI Fun1Proc(
LPVOID lpParameter // thread data
);

DWORD WINAPI Fun2Proc(
LPVOID lpParameter // thread data
);

int tickets=100;

CRITICAL_SECTION g_csA;
CRITICAL_SECTION g_csB;

void main()
{
HANDLE hThread1;
HANDLE hThread2;
hThread1=CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);
hThread2=CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);
CloseHandle(hThread1);
CloseHandle(hThread2);

InitializeCriticalSection(&g_csA);
InitializeCriticalSection(&g_csB);
Sleep(4000);

DeleteCriticalSection(&g_csA);
DeleteCriticalSection(&g_csB);
}

DWORD WINAPI Fun1Proc(
LPVOID lpParameter   // thread data
)
{
while(TRUE)
{
  EnterCriticalSection(&g_csA);
  Sleep(1);
  EnterCriticalSection(&g_csB);
  if(tickets>0)
  {
   Sleep(1);
   cout<<"thread1 sell ticket : "<<tickets--<<endl;
  }
  else
   break;
  LeaveCriticalSection(&g_csB);
  LeaveCriticalSection(&g_csA);
}

return 0;
}

DWORD WINAPI Fun2Proc(
LPVOID lpParameter   // thread data
)
{

while(TRUE)
{
  EnterCriticalSection(&g_csB);
  Sleep(1);
  EnterCriticalSection(&g_csA);
  if(tickets>0)
  {
   Sleep(1);
   cout<<"thread2 sell ticket : "<<tickets--<<endl;
  }
  else
   break;
  LeaveCriticalSection(&g_csA);
  LeaveCriticalSection(&g_csB);
}
cout<<"thread2 is running!"<<endl;
return 0;
}

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总结－－windows线程同步的三种方法的比较（互斥对象、事件对象与关键代码段的比较）：