asked on

How to test if a thread has ended

Hello all,

I have a CWinThread derived class that I am using. Occationally while the thread is running I will post it thread messages using PostThreadMessage() which works fine. The object is deleted when the threads finishes the Run() function because I have set m_bAutoDelete = TRUE. However, if the thread ends before I expected it to, I get an error because I am trying to PostThreadMessage to an object that no longer exists.

How can I test to see if PostThreadMessage is going to cause an error because the object is deleted?

Thanks

jymmealey

ASKER

Here is a some code to explain what I am talking about

m_pPingThread = (Ping_Thread*) AfxBeginThread(RUNTIME_CLASS(Ping_Thread), THREAD_PRIORITY_NORMAL, 0, CREATE_SUSPENDED);
m_pPingThread->ResumeThread();

while (true) {
m_pPingThread->PostThreadMessage(WM_USER + 1, 0, 0);
Sleep(1000);
}

Once the "Ping_Thread" ends I will get an error trying to post at thread message

jkr

You could use

DWORD dw;
GetExitCodeThread(m_pPingThread->m_hThread, &dw);

if ( STILL_ACTIVE == dw) {

// still running
}

jymmealey

ASKER

Won't that still error because I am still trying to access the member of a deleted object?

jkr

Sorry, that's of course correct. Do you really net to set it to ''AutoDelete'? I.e.

while (true) {
DWORD dw;
GetExitCodeThread(m_pPingThread->m_hThread, &dw);

if ( STILL_ACTIVE == dw) {

// still running
m_pPingThread->PostThreadMessage(WM_USER + 1, 0, 0);

} else {

m_pPingThread = NULL;

break;
}

Sleep(1000);
}

would seem a lot 'healthier' to me (the above assumes 'm_bAutoDelete == FALSE')

jymmealey

ASKER

I don't have to but how do I get the object to delete after I am done with it?

ASKER CERTIFIED SOLUTION

jkr

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jymmealey

ASKER

I tried that but I am getting a complier error saying
error C2248: 'Ping_Thread::~Ping_Thread' : cannot access protected member declared in class 'Ping_Thread'

Do I just need to move the desctructor to a private rather than protected?

jkr

>>Do I just need to move the desctructor to a private rather than protected?

No, better move it to the 'public:' section.