Re: CMutex /CEvent (multiple threads)

From:

"Anthony Wieser" <newsgroups-sansspam@wieser-software.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Wed, 23 Sep 2009 16:59:04 +0100

Message-ID:

<#f7E$dGPKHA.3552@TK2MSFTNGP04.phx.gbl>

Curiouser and Curioser:

http://support.microsoft.com/kb/141533
says that this bug was fixed in MFC 4.1

Visual Studio 6 implements it this way in mtcore.cpp:
BOOL CSyncObject::Lock(DWORD dwTimeout)
{
if (::WaitForSingleObject(m_hObject, dwTimeout) == WAIT_OBJECT_0)
  return TRUE;
else
  return FALSE;
}

Yet vc2005 implements it the old way in mtcore.cpp:
BOOL CSyncObject::Lock(DWORD dwTimeout)
{
DWORD dwRet = ::WaitForSingleObject(m_hObject, dwTimeout);
if (dwRet == WAIT_OBJECT_0 || dwRet == WAIT_ABANDONED)
  return TRUE;
else
  return FALSE;
}

I wonder what happened here?

Anthony Wieser
Wieser Software Ltd

"Joseph M. Newcomer" <newcomer@flounder.com> wrote in message
news:4fakb5d1pnnea71h1c8q7v9apm0impebn3@4ax.com...

See below...
On Wed, 23 Sep 2009 03:25:09 -0700 (PDT), Goran <goran.pusic@gmail.com>
wrote:

On Sep 23, 10:16 am, Joseph M. Newcomer <newco...@flounder.com> wrote:

Hmmm...from the MSDN documentation
*****
"The specified object is a mutex object that was not released by the
thread that owned the
mutex object before the owning thread terminated. Ownership of the mutex
object is granted
to the calling thread, and the mutex is set to nonsignaled.

If the mutex was protecting persistent state information, you should
check it for
consistency."
*****
So, how do I tell that the reason I have the mutex is because I had a
catastrophic failure
and need to check the state information for consistency, as opposed to I
have the mutex
because I acquired it cleanly? Note: I CANNOT TELL THAT IT FAILED!