Cpp_with_MFC官方实例----定时器的使用

//------ init ------ 
bool Cpp_with_MFC_Dlg::init(bool debug) 
{ int flags = debug ? 0 : KSF_DIRECT_EXEC;

  Error ksError;

  //------------------------------------------------------------------------------------------------------------ 
  // Opening the driver is always the first step! After that, we can use other functions. If the opening fails, 
  // no other function can be called. 
  // 
  // This function takes your customer number with Kithara (or "DEMO" or "BETA" if applicable) as a parameter. 
  //------------------------------------------------------------------------------------------------------------

  ksError = KS_openDriver(pCustomerNumber); //打开驱动，这是使用Kithara RTS的第一步 
  if (ksError) 
  { outputErr(ksError, "KS_openDriver", "Maybe incorrect customer number?"); 
    return false; 
  }


  //------------------------------------------------------------------------------------------------------------ 
  // If you wish to signal an application thread from the kernel level, it‘s best to have an event object, 
  // which can be set from the DLL. Therefore we create an event object here, in order to show the handling. 
  // It is possible to block a thread by calling KS_waitForEvent. 
  //------------------------------------------------------------------------------------------------------------

  ksError = KS_createEvent(    //创建事件，该事件之后将被放入共享内存中，由内核模式中的回调函数触发 
              &hEvent_,                                 // Address of event handle 
              "MyCpp_with_MFCEvent",             // Name of the event 
              0);                                       // Flags, here 0 
  if (ksError) 
  { outputErr(ksError, "KS_createEvent", "Unable to create required event!"); 
    KS_closeDriver(); 
    return false; 
  }


  //------------------------------------------------------------------------------------------------------------ 
  // Create and initialize the structure of type ‘TimerData‘, which is given to the timer callback routine as 
  // an argument. In difference to the timer example on the application level we have to create shared memory 
  // in order to give our callback routine some data, because normal variables are not accessible from the 
  // kernel-mode. We can access the memory from application level using the ‘pAppPtr_‘, access from the kernel 
  // level can be done using the ‘pSysPtr_‘. 
  //------------------------------------------------------------------------------------------------------------

  ksError = KS_createSharedMem( //创建共享内存用于用户层（非实时）与内核层（实时）进行通信，共享内存为结构体TimerData，包含一个计数器counter和一个句柄事件hEvent_ 
              (void**)&pAppPtr_,                        // Address of application pointer 
              (void**)&pSysPtr_,                        // Address of kernel pointer 
              "MyCpp_with_MFCMem",               // Name of shared memory area 
              sizeof(TimerData),                        // Size of shared memory area 
              0);                                       // Flags, here 0 (see manual) 
  if (ksError) 
  { outputErr(ksError, "KS_createSharedMem", "Unable to create shared memory!"); 
    KS_closeDriver(); 
    return false; 
  }

  pAppPtr_->hEvent_   = hEvent_;                        // Save the created event 把事件放入共享内存中 
  pAppPtr_->counter_  = 0;                              // Clear the timer counter     计数器置0


  //------------------------------------------------------------------------------------------------------------ 
  // In order to use functions from the DLL on the kernel level, it must have been loaded first. 
  // 
  // Attention! The DLL must be found by the loader, so it should be placed in a directory, which is part of 
  // the search path! 
  // 
  // Attention! The return value of KS_loadKernel is primarily the success condition of the loading process. 
  // If you specify an initialization routine, the return value is furthermore the return of that 
  // initialization function! 
  //------------------------------------------------------------------------------------------------------------

  ksError = KS_loadKernel(                   // 载入Kernel.dll程序资源文件，用hKernel表示该资源文件路径 
              &hKernel_,                                // Kernel handle 
              "Kernel.dll",                             // Name of DLL 
              "_initFunction",                          // Name of init routine 
              debug ? pAppPtr_ : pSysPtr_,              // Init parameter 
              flags);                                   // Flags, load where chosen 
  if (ksError) 
  { outputErr(ksError, "KS_loadKernel", "Unable to load and initialize DLL! Possibly the DLL is not in the search path?"); 
    KS_closeDriver(); 
    return false; 
  }


  //------------------------------------------------------------------------------------------------------------ 
  // Now create the callback. This one is called in the DLL every time the timer period has expired. The flag 
  // KSF_DIRECT_EXEC is set, so the callback routine can be executed within realtime context. 
  // 
  // Accepted flags are: 
  // 
  // KSF_USER_EXEC:   - execution on application level 
  // KSF_KERNEL_EXEC: - execution on kernel level (synchronously) 
  // KSF_DIRECT_EXEC: - execution on kernel level in realtime context 
  // KSF_SAVE_FPU:    - allow floating point calculation on kernel level 
  //------------------------------------------------------------------------------------------------------------

  ksError = KS_createKernelCallBack(  // 创建将timerCallBack映射为回调函数，存入hCallBack中 
              &hCallBack_,                              // Address of callback handle 
              hKernel_,                                 // Handle of kernel DLL 
              "_timerCallBack",                         // Name of callback function 
              debug ? pAppPtr_ : pSysPtr_,              // Reference parameter to the callback 
              flags,                                    // Flags, here kernel level (ISR) 
              16);                                      // Priority, only used on Ring3 
  if (ksError) 
  { outputErr(ksError, "KS_createKernelCallBack", "Unable to create kernel callback!"); 
    KS_closeDriver(); 
    return false; 
  }


  //------------------------------------------------------------------------------------------------------------ 
  // Please note, that the minimum theoretic timer period is 1 microsecond. This value is automatically 
  // increased to a valid value, which is adjusted to the actual CPU performance. 
  // 
  // ATTENTION! Real-time timers are only available when having the RealTime Module! 
  // If not: 
  //   - remove the flag KSF_REALTIME_EXEC from KS_createTimer! 
  // 
  //------------------------------------------------------------------------------------------------------------ 
  // Create the timer with the chosen period. The signalization object is the ‘hCallBack_‘ parameter. Accepted 
  // flags are: 
  // 
  // KSF_REALTIME_EXEC:  - the real-time kernel is to be used (this is only possible after the timer resolution 
  //                       has been set!) 
  // KSF_DONT_START:     - don‘t start the timer (can be started later) 
  // KSF_ONE_SHOT:       - signal timer only one time 
  // 
  // Please note, that the minimum timer period is 1 microsecond. 
  //------------------------------------------------------------------------------------------------------------

  ksError = KS_createTimer(                 // 创建定时器 
              &hTimer_,                                 // Address of timer handle，定时器句柄 
              1 * ms,                                   // Timer period in 100-ns-units，定时周期 
              hCallBack_,                               // Callback handle，回调函数，用于周期回调 
              debug ? KSF_DONT_START                    // Flags ，本处做了一个判断处理，如果用于调试则把定时器回调函数放在用户层执行，如果是非调试模式则放入实时模式执行 
                    : KSF_REALTIME_EXEC | KSF_DONT_START); 
  if (ksError) 
  { outputErr(ksError, "KS_createTimer", "Unable to create the timer!"); 
    KS_closeDriver(); 
    return false; 
  }

  return true; 
}

void Cpp_with_MFC_Dlg::TimerButton() 
{ 
  Error ksError = KS_OK;

  CString text; 
  (GetDlgItem(IDC_BUTTON1))->GetWindowText(text); 
  if (!timerStarted_)//判断定时器启动状态，实现一个按钮两个功能 
  { 
    //---------------------------------------------------------------------------------------------------------- 
    // Then we restart the timer with the same period. We could program a new timer period if we want. Accepted 
    // flags are: 
    // 
    // KSF_ONE_SHOT:       - signal timer only one time 
    //----------------------------------------------------------------------------------------------------------

    ksError = KS_startTimer(           // 启动定时器 
                hTimer_,                                // Timer handle 
                0,                                      // Flags 
                1 * ms);                                // Timer period in 100-ns-units 
    if (ksError) 
      outputErr(ksError, "KS_startTimer", "Could not start the timer!"); 
    else { 
      timerStarted_ = true; 
      GetDlgItem(IDC_BUTTON1)->SetWindowText("Stop timer!"); 
    }

    KS_pulseEvent(pAppPtr_->hEvent_);

  } 
  else 
  { ksError = KS_stopTimer(hTimer_);//停止定时器 
    if (ksError) 
      outputErr(ksError, "KS_stopTimer", "Unable to stop the timer!"); 
    else { 
      timerStarted_ = false; 
      GetDlgItem(IDC_BUTTON1)->SetWindowText("Start timer!"); 
    } 
  } 
}

// ------ OnTimer ------ 
void Cpp_with_MFC_Dlg::OnTimer(UINT_PTR nIDEvent) 
{ if (!initResult_) 
  { GetDlgItem(IDC_LABEL1)->EnableWindow(false); 
    GetDlgItem(IDC_EDITCOUNTER)->EnableWindow(false); 
    GetDlgItem(IDC_BUTTON1)->EnableWindow(false); 
    KillTimer(1); 
  } 
  else if (timerStarted_) 
  { CString text; 
    Error ksError = KS_waitForEvent(pAppPtr_->hEvent_, 0, 1000 * ms); //等待内核内的实时定时器回调函数触发该事件，然后才能执行 
    if (ksError == KS_OK) { 
      text.Format("%d", pAppPtr_ == NULL ? 0 : pAppPtr_->counter_); 
    } 
    else if (KSERROR_CODE(ksError) == KSERROR_WAIT_TIMEOUT) { 
      text = "Timeout occured!";                              //等待事件超过1s 
    } 
    else { 
      text.Format("error=%08X", ksError);             //其他错误 
    } 
    
    GetDlgItem(IDC_EDITCOUNTER)->SetWindowText(text);    //设置文本框 
  }

  CDialog::OnTimer(nIDEvent); 
}

extern "C" Error __declspec(dllexport) __stdcall _timerCallBack(void* pArgs, void* pContext) 
{ 
  //------------------------------------------------------------------------------------------------------------ 
  // When the function returns a value other than 0, the timer will be cancelled. 
  //------------------------------------------------------------------------------------------------------------

  if( !_pData )// _pData为共享内存句柄，在_initFunction函数中将其映射到共享内存中 
    return KSERROR_BAD_PARAM;

  //------------------------------------------------------------------------------------------------------------ 
  // Output on screen is not allowed, so we simply increment the counter. 
  //------------------------------------------------------------------------------------------------------------

  ++_pData->counter_;                                   // Increment our counter

  //------------------------------------------------------------------------------------------------------------ 
  // Set event, which we will wait for in the ring 3 application 
  //------------------------------------------------------------------------------------------------------------

  if(_pData->counter_ % 500 == 0)// 
    KS_setEvent(_pData->hEvent_); //每满足500次触发事件，OnTimer函数中有等待该事件触发

  //------------------------------------------------------------------------------------------------------------ 
  // Remember: When the function returns a value other than 0, the timer will be cancelled. So, you have to 
  // return 0 (KS_OK) in most cases! 
  //------------------------------------------------------------------------------------------------------------

  return KS_OK; 
}