进程同步，进程锁

1. 进程同步方式

HANDLE hMutex = CreateMutex(NULL, FALSE, "xiaoyu2");     //创建有名互斥量
   if (NULL == hMutex)
   {
    cout << "create mutex fail" << endl;
   }
   DWORD dwErrno = GetLastError();
   bool bClient = false;
   if (ERROR_ALREADY_EXISTS == dwErrno)
   {
    cout << "mutex already exist." << endl;
    CloseHandle(hMutex);
    hMutex = OpenMutex(SYNCHRONIZE, FALSE, "xiaoyu2");
    bClient = true;
   }
  while(1)
   {    Sleep(1000);
    cout << "wait to get mutex" << endl;
    WaitForSingleObject(hMutex, INFINITE);    //一个进程获得后，在它Release之前，其他进程无法获得
    cout << "get mutex" << endl;
    int bSigned;
    cin >> bSigned;    
    ReleaseMutex(hMutex);
    cout << "releae mutex" << endl;  }