Re: Worker thread
On Thu, 8 Mar 2012 08:58:04 -0800 (PST), scottmcp@mvps.org wrote:
There is not any safe and clean way to stop the thread immediately. The SuspendThread and TerminateThread APIs can do it, but are not recommended for routine use. The best way to stop the thread quickly is to eliminate the Sleep() calls in the thread. You have the option of making it a message-driven thread and using a timer (WM_TIMER) instead of Sleep() calls. Another option is to use an event instead of a bool to stop the thread. The thread can use WaitForSingleObject to suspend itself until the event is set OR a timeout elapses.
When starting the thread you can pass a pointer (where you now pass m_hWnd). That could be a pointer to anything. A pointer to a struct would let you pass a collection of things, or maybe just pass the 'this' pointer so the thread can access dialog member variables.
When the thread does PostMessage you can pass a pointer in wParam and/or lParam. For example, the thread could allocate a CString or char array from the heap and pass the pointer. The main thread message handler must delete the pointer after receiving it.
//I have in header unsigned char MyData[32];
//I want the data in this array to be able to be used within the thread and
//then returned with the modified data.
//I have this now
void CAdelphiXDlg::OnTest()
{
AfxBeginThread(runThread,(LPVOID)m_hWnd); //works
c_Info.SetWindowText("Thread Started...");
}
//How do I change it to pass the that unsigned char array?
===========================================================================
//how do I retrieve the unsigned char array in the thread below?
UINT runThread( LPVOID Param )
{
HWND hDlg = (HWND)Param;
KillThread = false;
do{
MessCode = 0; //started
::PostMessage(hDlg, RunMsg, (WPARAM)0, (LPARAM)0);
//do code manipulation which can take up to 30secs
//which is why I might need to kill if stuck
MessCode = 1; //finished
::PostMessage(hDlg, RunMsg, (WPARAM)0, (LPARAM)0);
}while(!KillThread);
return 0;
}