FIX: Transforms Used in ExtCreateRegion Cause Leak (153808)
The information in this article applies to:
- Microsoft Win32 Application Programming Interface (API), when used with:
- Microsoft Windows NT Server 3.51
- Microsoft Windows NT Workstation 3.51
This article was previously published under Q153808 SYMPTOMS
Calling ExtCreateRegion with a transformation matrix in the XForm parameter
causes a small leak in system resources.
This can be viewed by watching the Private Bytes reported by the
Performance Monitor (perfmon.exe) for the CSRSS process. Each call to
ExtCreateRegion results in a slight increase to the allocated private bytes
for CSRSS that are not returned to the system, even when the application
exits. Several thousand calls to ExtCreateRegion are necessary before the
leak is evident in the Performance Monitor.
RESOLUTION
To work around the problem, do not call ExtCreateRegion with a
transformation. Always call this function with a NULL parameter for XForm.
Similar functionality can be achieved by creating the region without a
transformation and then setting a World Transformation with the
SetWorldTransform function prior to using the Region.
If the goal is a transformed region without altering World Transformations,
the application performs the necessary matrix calculations to
transform region data prior to its creation.
STATUSMicrosoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
| Modification Type: | Minor | Last Reviewed: | 3/21/2005 |
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| Keywords: | kbBug kbfix kbOSWinNT400fix KB153808 |
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