FIX: Memory Leak Reported in PLEX.CPP When Using CSocket (136080)
The information in this article applies to:
- The Microsoft Foundation Classes (MFC), when used with:
- Microsoft Visual C++, 32-bit Editions 2.1
- Microsoft Visual C++, 32-bit Editions 2.2
This article was previously published under Q136080 SYMPTOMS
Running an application that uses the CSocket class causes a memory leak
report to be generated when the application exits. The memory leak report
will be similar to this:
{1555} plex.cpp(28) : non-object block at $002ECC8C, 132 bytes long
CAUSE
The CSocket class will queue up socket notification messages while it waits
for a particular socket operation to complete. These messages are stored in
CPtrList (m_listSocketNotifications) on a per-thread basis. This object is
destroyed when the thread-state information for that thread is cleaned-up.
Unfortunately the thread-state information for the primary thread is not
cleaned-up until after the memory leak detection is performed.
Because MFC does not take care to free the plex objects associated with
this list before the list is destroyed, the perceived memory leak is
reported.
Because the problem is related to the frequency and sequence of the socket
notification messages being received, the memory leak message might not
occur every time the program is executed. It might only be seen under
certain circumstances.
RESOLUTION
This message will only occur when CSocket objects are used in the primary
thread. The message can be safely ignored because the
m_listSocketNotifications object is actually being safely deleted before
the application exits, so the memory will be freed then.
STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article. This problem was fixed in Microsoft
Visual C++, 32-bit Edition, version 4.0.
| Modification Type: | Major | Last Reviewed: | 10/24/2003 |
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| Keywords: | kbBug kbfix kbNoUpdate kbVC400fix kbWinsock KB136080 |
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