Re: EnterCriticalSection() is corrupting my heap

From:
Norman Bullen <norm@BlackKittenAssociates.com.INVALID>
Newsgroups:
microsoft.public.vc.language
Date:
Thu, 25 May 2006 03:13:31 GMT
Message-ID:
<vh9dg.4820$921.3806@newsread4.news.pas.earthlink.net>
Arsalan Ahmad wrote:

Nice guess ;-) but i have called InitializeCriticalSection()...

"Murrgon" <murrgon@hotmail.com> wrote in message
news:u49tZ9zfGHA.3900@TK2MSFTNGP05.phx.gbl...

You haven't called InitializeCriticalSection(&m_cs). Without
doing this, you are using an unitialized critical section.

Arsalan Ahmad wrote:

Hi,

Yes i use HeapCreate() and HeapAlloc().

I have a class object which is created on the heap and I have a member
variable in this class of type CRITICALSECTION (say m_cs). Inside one of
my class function when I call EnterCriticalSection(&m_cs) then this
problem occurs. Ok may be its not because of critical section because at
the place in code where EnterCriticalSection() was being called I create
and CAutoLock() object and pass my pointer to CRITICALSECTION object to
it (CAutoLock just call EnterCriticalSection in its constructor and
LeaveCriticalSection in its destructor). In the constructor when I try to
save pointer of critical section to the class member (CRITICALSECTION
*m_pCS) of CAutoLock then although it is pointer assignment but after
assignement the class member has some garbage data.

In my outside code:

{
   CAutoLock(&m_cs);

   // Some code
}

CAutoLock::CAutoLock(CRITICALSECTION *pCS)
{
   m_pCS = pCS; <= This assignement is not working correctly and after
assignment m_pCS points to some garbage memory location
   EnterCriticalSection(m_pCS);
}

So any idea what is wrong?

Thanks,

Arsalan

Any idea whats wrong?

"Oleg Starodumov" <com-dot-debuginfo-at-oleg> wrote in message
news:esmFGFzfGHA.4792@TK2MSFTNGP03.phx.gbl...

I have developed a static library which I am using in one of my
application.
In my library I have created my own heap and all the objects (class
objects)
in my application are created in that heap. What I have observed is
that in
my library at a certain place when I call EnterCriticalSection() to an
object allocated at my heap, it is corrupting my heap. I am using
Windows XP
and visual studio 8.0. Any hint how can I solve this problem?


How exactly do you create and use the heap?
Do you use HeapCreate/HeapAlloc/etc., or some other approach?
How do you detect the heap corruption?
How do you allocate memory for the CRITICAL_SECTION structure?
How do you pass this CRITICAL_SECTION to EnterCriticalSection?

Code samples would be helpful.

Regards,
Oleg
[VC++ MVP http://www.debuginfo.com/]


Does your class have a copy constructor?

If it does, how does it initialize the critical section in the new object?

If it does not, how do you know that a default copy constructor has not
been generated? Add a _private_ copy constructor without any
implementation to the class declaration to prevent inadvertent use of a
generated copy constructor.

Norm

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