Memory Leak in Os2srv.exe (266334)



The information in this article applies to:

  • Microsoft Windows NT Workstation 4.0
  • Microsoft Windows NT Server 4.0
  • Microsoft Windows NT Server, Enterprise Edition 4.0

This article was previously published under Q266334

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 that is described in this article. Apply it only to computers that are 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 about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual 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 that this is a problem in the Microsoft products that are listed at the beginning of this article.

Modification Type:MinorLast Reviewed:9/26/2005
Keywords:kbHotfixServer kbQFE kbbug kbfix KB266334