Article ID: 124121
Article Last Modified on 11/1/2006
APPLIES TO
- Microsoft Windows NT Workstation 3.5
- Microsoft Windows NT Server 3.5
This article was previously published under Q124121
SYMPTOMS
An application which periodically starts Command Prompt commands or utilities (32-bit applications) may exhibit symptoms of a memory resource allocation problem. To observe this problem, you can use Performance Monitor to view nonpaged pool memory. The application in question regularly allocates more and more nonpaged pool memory until system memory resources are exhausted. This can result in poor system performance and disk "thrashing" (a condition where the hard disk drive is constantly being accessed, even in periods of little system activity).
The following error message may appear when system memory is finally exhausted:
NOTE: The symptoms are not evident using the same application under Windows NT version 3.1.
CAUSE
When an application spawns a process repeatedly, a new thread instance will be created for each process but the previous instances may not be cleaned up. This results in a significant virtual memory loss each time the process is spawned. Executing the following Win32 calls will result in the same memory loss symptoms listed above.
CreateProcess(anyprocess,...,............, &pi);
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
NOTE: If there is a WaitForInputIdle() call between CreateProcess() and CloseHandle(),the problem does not occur.
RESOLUTION
WINSRV.DLL was modified to correct this behavior. Even when processes are repeatedly created by an application, WINSRV.DLL ensures that the process and thread handles are closed upon command.
STATUS
Microsoft has confirmed this to be a problem in Windows NT version 3.5. This problem was corrected in the latest U.S. Service Pack for Windows NT version 3.5. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):
S E R V P A C K
Additional query words: prodnt 3.50
Keywords: kbprb KB124121
