Understanding Custom Marshaling Part 1

#include "utilities.h"

DWORD ThreadMsgWaitForSingleObject (HANDLE hHandle, DWORD dwMilliseconds)
{
  HANDLE	dwChangeHandles[1] = { hHandle };
  DWORD		dwWaitStatus = 0;
  DWORD		dwRet = 0;
  bool		bContinueLoop = true;

  // Msg Loop while waiting for hHandle to be signaled.
  while (bContinueLoop) 
  {
    // Wait for notification.
    dwWaitStatus = ::MsgWaitForMultipleObjectsEx
	(
      (DWORD)1,          // number of handles in array
      dwChangeHandles, // object-handle array
      (DWORD)dwMilliseconds,  // time-out interval
      (DWORD)(QS_ALLINPUT | QS_ALLPOSTMESSAGE),      // input-event type
      (DWORD)(MWMO_INPUTAVAILABLE)          // wait options
    );
 
    switch (dwWaitStatus) 
    { 
      // First wait (hHandle) object has been signalled.
	  case WAIT_OBJECT_0 : 
	  {
	    dwRet = dwWaitStatus;
        // Flag to indicate stop loop.
		bContinueLoop = false;
	    break;
	  }

      // Windows message has arrived.
      case WAIT_OBJECT_0 + 1: 
	  {
	    MSG msg;

        // Dispatch all windows messages in queue.
	    while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
	    {
	      TranslateMessage (&msg);
		  DispatchMessage(&msg);
	    }

	    break; 
	  }

      // Timeout has elapsed.
	  case WAIT_TIMEOUT :
	  {
	    dwRet = dwWaitStatus;
        // Flag to indicate stop loop.
		bContinueLoop = false;
	    break;
	  }
 
      default: 
	  {
	    break;
	  }
    } 
  }

  return dwRet;
}





DWORD ThreadMsgWaitForMultipleObjects 
(
  DWORD dwCount, 
  LPHANDLE pHandles, 
  BOOL bWaitAll, 
  DWORD dwMilliseconds
)
{
  HANDLE_VECTOR	vec_Handle;
  DWORD			dwWaitStatus = 0;
  DWORD			dwRet = 0;
  DWORD			dwCountCurrent = 0;
  DWORD			dw = 0;
  bool			bContinueLoop = true;

  if ((dwCount == 0) || (pHandles == NULL))
  {
    return 0;
  }

  dwCountCurrent = dwCount;

  // Initialize our vector of handles.
  for (dw = 0; dw < dwCountCurrent; dw++)
  {
    vec_Handle.push_back(pHandles[dw]);
  }

  // Msg Loop while waiting for hHandle to be signaled.
  while (bContinueLoop) 
  {
    // Wait for notification.
    dwWaitStatus = ::MsgWaitForMultipleObjectsEx
	(
      (DWORD)dwCountCurrent,          // number of handles in array
      &(vec_Handle[0]), // object-handle array
      (DWORD)dwMilliseconds,  // time-out interval
      (DWORD)(QS_ALLINPUT | QS_ALLPOSTMESSAGE),      // input-event type
      (DWORD)(MWMO_INPUTAVAILABLE)          // wait options
    );

	if ((dwWaitStatus >= WAIT_OBJECT_0) && (dwWaitStatus <= (WAIT_OBJECT_0 + dwCountCurrent - 1)))
	{
	  // A wait handle object in pHandles array has been signalled.
	  // Check to see if bWaitAll is true or false.
	  if (bWaitAll)
	  {
	    // We need to wait on ALL handles.
		// Hence we need to call MsgWaitForMultipleObjectsEx() again
		// with the same vec_Handle but minus the handle which has 
		// just been signaled.
		DWORD	dwIndex = dwWaitStatus - WAIT_OBJECT_0;
		HANDLE	hHandleJustSignaled = vec_Handle[dwIndex];

        // Reduce our current count of handles.
		dwCountCurrent--;

		if (dwCountCurrent <= 0)
		{
		  // No more handles to wait on.
		  // Return a zero value.
	      dwRet = 0;
          // Flag to indicate stop loop.
		  bContinueLoop = false;
		}
		else
		{
		  // First make a copy of the current vector
		  HANDLE_VECTOR	vec_HandleTemp = vec_Handle;

          // Clear our vector of handles.
          vec_Handle.clear();
          // Re-initialize our vector of handles.
		  // Note : we use vec_HandleTemp.size().
		  // MUST NOT use "dwCountCurrent" - it has already
		  // been reduced by 1.
          for (dw = 0; dw < vec_HandleTemp.size(); dw++)
          {
		    if (vec_HandleTemp[dw] != hHandleJustSignaled)
			{
              vec_Handle.push_back(vec_HandleTemp[dw]);
			}
          }
		}
	  }
	  else
	  {
	    dwRet = dwWaitStatus;
        // Flag to indicate stop loop.
		bContinueLoop = false;
	  }
	}
	else if (dwWaitStatus == WAIT_OBJECT_0 + dwCountCurrent)
	{
	  // Windows message has arrived.
	  MSG msg;

      // Dispatch all windows messages in queue.
	  while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
	  {
	    TranslateMessage (&msg);
	    DispatchMessage(&msg);
	  }
	}
	else if (dwWaitStatus == WAIT_TIMEOUT)
	{
	  // Timeout has elapsed.
	  dwRet = dwWaitStatus;
      // Flag to indicate stop loop.
	  bContinueLoop = false;
	}
  }

  return dwRet;
}