Is this function thread-safe?
- by kiddo
Hello all,I am learning multi-threading and for the sake of understanding I have wriiten a small function using multithreading...it works fine.But I just want to know if that thread is safe to use,did I followed the correct rule.
void CThreadingEx4Dlg::OnBnClickedOk()
{
//in thread1 100 elements are copied to myShiftArray(which is a CStringArray)
thread1 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction1,this);
WaitForSingleObject(thread1->m_hThread,INFINITE);
//thread2 waits for thread1 to finish because thread2 is going to make use of myShiftArray(in which thread1 processes it first)
thread2 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction2,this);
thread3 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction3,this);
}
UINT MyThreadFunction1(LPARAM lparam)
{
CThreadingEx4Dlg* pthis = (CThreadingEx4Dlg*)lparam;
pthis->MyFunction(0,100);
return 0;
}
UINT MyThreadFunction2(LPARAM lparam)
{
CThreadingEx4Dlg* pthis = (CThreadingEx4Dlg*)lparam;
pthis->MyCommonFunction(0,20);
return 0;
}
UINT MyThreadFunction3(LPARAM lparam)
{
CThreadingEx4Dlg* pthis = (CThreadingEx4Dlg*)lparam;
WaitForSingleObject(pthis->thread3->m_hThread,INFINITE);
//here thread3 waits for thread 2 to finish so that thread can continue
pthis->MyCommonFunction(21,40);
return 0;
}
void CThreadingEx4Dlg::MyFunction(int minCount,int maxCount)
{
for(int i=minCount;i<maxCount;i++)
{
//assume myArray is a CStringArray and it has 100 elemnts added to it.
//myShiftArray is a CStringArray -public to the class
CString temp;
temp = myArray.GetAt(i);
myShiftArray.Add(temp);
}
}
void CThreadingEx4Dlg::MyCommonFunction(int min,int max)
{
for(int i = min;i < max;i++)
{
CSingleLock myLock(&myCS,TRUE);
CString temp;
temp = myShiftArray.GetAt(i);
//threadArray is CStringArray-public to the class
threadArray.Add(temp);
}
myEvent.PulseEvent();
}
