使用信标对象实现线程同步

 使用信标对象实现线程同步
  信标对象也属于系统内核对象之一，它包含有计数，当使用计数为0时，信标对象处于无信号状态；
当使用计数大于0时，信标计数处于有信号状态。
   相关函数：
   CreateSemaphore:用于创建一个信标对象
   HANDLE CreateSemaphore(LPSECURITY_ATTRIBUTES lpSemaphoreAttributes,LONG                             lInitialCount,LONG lMaxinumCount,LPCTSTR lpName);
         lpSemaphoreAttributes:表示安全属性，可以是NULL
         lInitialCount：初始计数
         lMaxinumCount：最大计数
         lpName：信标名称
  ReleaseSemaphore：用于递增信号量的使用计数
 BOOL ReleaseSemaphore(HANDLE hSemphore,LONG lReleaseCount,LPLONG lpPreviousCount)
        hSemphore:句柄
        lReleaseCount信标的递增数量
        lpPreviousCount：用于返回之前的信标的使用计数
示例：
UINT output11(LPVOID pThreadParam)
{
 CString text;
 CAccessConflictDlg *pdlg=(CAccessConflictDlg *)pThreadParam;
 long nCount=0;
 while(pdlg->m_count<=100)
 {
  WaitForSingleObject(pdlg->m_semaphore,INFINITE);//等待信标对象有信号
  text.Format("线程一输出%d",pdlg->m_count);
  pdlg->m_count++;
  pdlg->m_list.AddString(text);
  Sleep(100);
  ReleaseSemaphore(pdlg->m_semaphore,1,&nCount);
 }
 return 0;
}
UINT output22(LPVOID pThreadParam)
{
 CString text;
 CAccessConflictDlg *pdlg=(CAccessConflictDlg *)pThreadParam;
 long nCount=0;
 while(pdlg->m_count<=100)
 {
  WaitForSingleObject(pdlg->m_semaphore,INFINITE);//等待信标对象有信号
  text.Format("线程二输出%d",pdlg->m_count);
  pdlg->m_count++;
  pdlg->m_list.AddString(text);
  Sleep(100);
     ReleaseSemaphore(pdlg->m_semaphore,1,&nCount);
 }
 return 0;
}
void CAccessConflictDlg::OnButton1()
{
  m_semaphore=CreateSemaphore(NULL,1,100,"sem");
 output1=AfxBeginThread(output11,this,0,0,0,NULL);
 output2=AfxBeginThread(output22,this,0,0,0,NULL);
 CloseHandle(output1->m_hThread);
 CloseHandle(output2->m_hThread);
 // TODO: Add your control notification handler code here
 
}