asked on

Killing a Thread outside the thread function

I want to kill a thread, AfxBeginThread(...). It is given that I can do so within the thread. I want to kill on pressing a command button.
Jalaja

ASKER CERTIFIED SOLUTION

zhaowei

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

rayb

You must be careful when using the TerminateThread API. When this function is called the thread will have no opportunity to perform any cleanup whatsoever.
Often a better solution is to stash an abort flag somewhere, perhaps in your CWinApp object. The thread should have code to check this flag every once in a while and the command button can set the flag.

piano_boxer

If your child thread is spending a lot of time waiting (with WaitForSingleObject() or simular), you could create a global manually event.

Modify you thread function to take the event into account:

----

extern HANDLE g_hAbortThreadSignal;

void MySmartThreadFunc(LPVOID lpvParam)
{
[....]

HANDLE hWaitHandles[] = { hSomeHandle, g_hAbortThreadSignal };
while(1)
{
DWORD dwResult = WaitForMultipleObjects(2, hWaitHandles, FALSE, INFINITE);

if(dwResult == (WAIT_OBJECT_0+1))
{
// Our abort signal set, exit thread function
return 0;
}

//
// Normal processing goes here!
//
}
return 0;
}

----

// To create the manual reset event insert this in CWinApp::InitInstance() or simular:

HANDLE g_hAbortThreadSignal;
g_hAbortThreadSignal = CreateEvent(NULL, TRUE, FALSE, NULL);

// Remember to destroy the event when exiting the app:
CloseHandle(g_hAbortThreadSignal);

---

// To make the child thread exit, just signal the event from somewhere using the SetEvent() function:
SetEvent(g_hAbortThreadSignal);

// (Remember to reset it again if you start the child thread again!)

piano_boxer

Mistake, mistake.... The thread function should not return anything. Replace 'return 0' with just 'return'.