DOCUMENT:Q266334 08-MAY-2002 [winnt] TITLE :Memory Leak in Os2srv.exe PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS:kbWinNT400PreSP7Fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation version 4.0 - Microsoft Windows NT Server version 4.0 - Microsoft Windows NT Server, Enterprise Edition version 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== You might notice a small memory leak on Os2srv.exe. You can observe the leak on the Process tab in Task Manager under VM Size. The value increases by 4 KB at time intervals that do not seem to be directly related to running individual OS/2-based programs. CAUSE ===== When an OS/2-based program uses the DosSetSigHandler function to install its own signal handler, Os2srv.exe allocates a small amount of heap memory to record details of the signal handler. These registered signal-handler records are associated with an internal OS/2 Session object. However, when the OS/2-based program quits, the registered signal-handler records are not being freed because the routine that is designed to free them is being called after the Session object is dereferenced. If enough programs that install their own signal handlers run, these small heap allocations eventually exhaust the available heap, which is then expanded by committing an extra 4-KB block of heap memory. RESOLUTION ========== A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: Date Time Size File name Platform ------------------------------------------------- 06/23/2000 05:28p 130,832 Os2srv.exe Intel STATUS ====== Microsoft has confirmed this to be a problem in the Microsoft products that are listed at the beginning of this article. Additional query words: ====================================================================== Keywords : kbWinNT400PreSP7Fix Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400 Version : winnt:4.0 Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.