Improve company productivity with a Business Account.Sign Up

x
?
Solved

About CCriticalSection

Posted on 1998-11-18
2
Medium Priority
?
205 Views
Last Modified: 2013-11-20
Hi!
I have some threads, which can call a function from a single
object, let's say CBoss.
 When I declare a CCriticalSection class in the header of
CBoos (       CCriticalSection m_readSection;)
and I try to access the function of this class from a thread-class in the next way:

CSingleLock m_readSection(&m_pDoc->m_readSection, FALSE);
m_readSection.Lock(INFINITE);
m_pDoc->ReadMsg(pMsg, this);
m_readSection.Unlock();

the thread stops on the second Lock (i.e. when I try to lock the second time the CriticalSection, the thread begin to wait, even if the CSingleLock object - m_readSection is
not locked- I have checked this). There is only one thread,
so doesn't exist another thread to lock this critical section.

When I use in the CBoss header       

static CRITICAL_SECTION m_readSect;
and I try to access the function of this class from a thread class in the next way:
EnterCriticalSection(&m_pDoc->m_readSect);
{
      m_pDoc->ReadMsg(pMsg, this);
}
LeaveCriticalSection(&m_pDoc->m_readSect);

it's OK.

What's wrong with the use of MFC classes?





0
Comment
Question by:visualc
2 Comments
 
LVL 15

Accepted Solution

by:
Tommy Hui earned 100 total points
ID: 1324929
The problem is you are passing the critical section by value. Generally this makes a copy and most MFC classes do not have copy semantics. You should pass the critical section by reference (CCriticalSection&) or by pointer (CCriticalSection*).
0
 

Author Comment

by:visualc
ID: 1324930
Hi,
I think that is another problem, because if I modify the declaration of m_readSection to
CCriticalSection* m_readSection;
and I use in this way -->
CSingleLock m_readSection(m_pDoc->m_readSection, FALSE);
if (m_readSection.IsLocked())
    MessageBeeP(1000);
m_readSection.Lock(INFINITE);
m_pDoc->ReadMsg(pMsg, this);
m_readSection.Unlock();

the problem is the same. When I try the second time, the code doesn't reach the MessageBeep command, so the CriticalSection is unlocked, but when I try to lock, the thread stops.
I don't have any idea, why.
0

Featured Post

The 14th Annual Expert Award Winners

The results are in! Meet the top members of our 2017 Expert Awards. Congratulations to all who qualified!

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Introduction: Dialogs (2) modeless dialog and a worker thread.  Handling data shared between threads.  Recursive functions. Continuing from the tenth article about sudoku.   Last article we worked with a modal dialog to help maintain informat…
Ready to get certified? Check out some courses that help you prepare for third-party exams.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
When you have multiple client accounts to manage, it often feels like there aren’t enough hours in the day. With too many applications to juggle, you can’t focus on your clients, much less your growing to-do list. But that doesn’t have to be the cas…

607 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question