使用Event同步线程

Win32写多线程的时候经常需要线程同步，同步的方法很多，效率也不一样，这里介绍一种Event同步对象。

建立一个MFC基于Dialog的工程，界面如图：


// 线程部分 全部为全局变量和函数
const int MAX_THREAD = 3;
HANDLE hEvent = NULL; // handle to event object
HANDLE hThread[MAX_THREAD];

DWORD WINAPI ThreadProc(LPVOID lpParameter)
{
 char buf[64];
 HWND hList = ::GetDlgItem(theApp.m_pMainWnd->m_hWnd, IDC_LISTRESULT);
 
 for(;;)
 {
  sprintf(buf, "Thread #%d Wait.", lpParameter);
  ListBox_SetTopIndex(hList, ListBox_AddString(hList, buf));
  WaitForSingleObject(hEvent, INFINITE);
  sprintf(buf, "Thread #%d work.", lpParameter);
  ListBox_SetTopIndex(hList, ListBox_AddString(hList, buf));
  Sleep(0);

 }
}

void StartThread(void)
{
 for(int i = 0; i < MAX_THREAD; i++)
 {
  hThread[i] = CreateThread(NULL, 0, ThreadProc, (LPVOID)i, 0, NULL);
 }
}

void KillThread(void)
{
 for(int i = 0; i < MAX_THREAD; i++)
 {
  if(hThread[i] != NULL)
  {
   TerminateThread(hThread[i], 0);
   WaitForSingleObject(hThread[i], INFINITE);
   CloseHandle(hThread[i]);
   hThread[i] = NULL;
  }
 }
}

// 按钮的一些消息函数
extern HANDLE hEvent;
void StartThread(void);
void KillThread(void);

void CEventDlg::OnBclean()
{
 // TODO: Add your control notification handler code here
 ListBox_ResetContent(::GetDlgItem(this->m_hWnd, IDC_LISTRESULT));
}

void CEventDlg::OnBpulse()
{
 // TODO: Add your control notification handler code here
 PulseEvent(hEvent);
}

void CEventDlg::OnBreset()
{
 // TODO: Add your control notification handler code here
 ResetEvent(hEvent);
}

void CEventDlg::OnBsetevent()
{
 // TODO: Add your control notification handler code here
 SetEvent(hEvent);
}

void CEventDlg::OnRauto()
{
 // TODO: Add your control notification handler code here
 KillThread();
 if(hEvent != NULL)
 {
  CloseHandle(hEvent);
 }
 hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
 StartThread();
}

void CEventDlg::OnRmanual()
{
 // TODO: Add your control notification handler code here
 KillThread();
 if(hEvent != NULL)
 {
  CloseHandle(hEvent);
 }
 hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
 StartThread();
}

代码中使用了一些例如类似 ListBox_ResetContent 的宏，需要引用 windowsx.h 头文件。如果不使用这些宏，可以直接调用 SendMessage 函数。

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