Re: worker thread

From:

mfc <mfcprog@googlemail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 5 Nov 2010 07:18:17 -0700 (PDT)

Message-ID:

<2e0e04cb-784a-4a5a-bbfd-a3ab76850b12@g25g2000yqn.googlegroups.com>

On 5 Nov., 14:21, Uwe Kotyczka <uwe.kotyc...@web.de> wrote:

On 5 Nov., 12:21, mfc <mfcp...@googlemail.com> wrote:

Ohh I like this answer :-)...

I tought so ;-)

Unfortunately, I don`t want to start the
worker thread in the document or view class.

I`ve my own class, called MyParamClass which is no subclass. This
class and the subclasses contains all information, which are needed
for the verificiation of the data. The verification will be done in
the worker thread.

So if the worker thread is only for the purpose of
verifying the data I would make all the variables
needed to control the worker thread memebers of
that class. That makes sence.

class MyParamClass
{
   void StartMyWorkerThread();

   protected:
   CWinThread* m_pWorkerThread;
   HANDLE m_hStopWorkerThread;

};

MyParamClass::MyParamClass()
{
        m_pWorkerThread = NULL;
        m_hStopWorkerThread = CreateEvent(NULL, TRUE, FALSE, NU=

LL); // manual

reset, initially not set

}

void MyParamClass::StartMyWorkerThread()
{
        // reset an old dead thread
        if (m_pWorkerThread != NULL)
        {
                DWORD dwExitCode;
                GetExitCodeThread(m_pWorkerThread->m_hThr=

ead, &dwExitCode);

if (dwExitCode == STILL_ACTIVE)
return; // worker thread =

already exists and is alive, do not start

it again
                else
                        m_pWorkerThread = NULL;
        }

        // give the m_hStopWorkerThread handle to the worker thre=

something->hStopWorkerThread = m_hStopWorkerThread;
m_pWorkerThread = AfxBeginThread(myThreadProc, something); =

//and

so on

}

void MyParamClass::ShutDownWorkerThreadSafely()
{
DWORD dwExitCode;
HANDLE hThread = m_pWorkerThread ? m_pWorkerThread->m_h=

Thread : NULL;

if (m_pWorkerThread != NULL &&
GetExitCodeThread(hThread, &dwExitCode) &=

                dwExitCode == STILL_ACTIVE)
        {
                // Stop the worker thread by setting the =

event.

                SetEvent(m_hStopWorkerThread);

                // Wait for thread to end itself
                while (GetExitCodeThread(hThread, &dwExit=

Code) &&

dwExitCode == STILL_A=

CTIVE)

{
WaitForSingleObject(hThre=

ad, 1);

                }
                m_pWorkerThread = NULL;
        }

}

void MyParamClass::~MyParamClass()
{
        ShutDownWorkerThreadSafely();
    ::CloseHandle(m_hStopWorkerThread);

}

UINT myThreadProc(LPVOID pParam)
{
        YourStruct* yourS = (YourStruct*)pParam;
        HANDLE hStopWorkerThread = yourS->hStopWorkerThread;

        while (true)
        {
                //Do something importnt

                //check hStopWorkerThread
                if (WaitForSingleObject(pDoc->hStopWorker=

Thread, 0)

== WAIT_OBJECT_0)
break; // Terminate this =

thread by existing the proc.

}

}

I`ve only installed one global variable installed for this
MyParamClass. In the thread I only do the verification, which means I
didn`t change any variable. After performing the verification and
everything was successfull, I will send a PostMessage back to the
mainthread to do all required changes.

So from you global variables you can call StartMyWorkerThread
resp. ShutDownWorkerThreadSafely (if you wish to).

HTH

thanks for your help and your time. I`ll take a look at your code
tonight.

best regards
Hans