KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q118471: BUG: Caching GDI Objects Causes Temporary GDI Resource Leak

Article: Q118471
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1
Operating System(s): 
Keyword(s): kbOSWin310 _IK kbSDKWin16
Last Modified: 09-JUL-1999

3.10
WINDOWS
kbprg kbbuglist

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
-------------------------------------------------------------------------------

SYMPTOMS
========

The amount of free GDI resources decreases as an application prints, especially
over the course of several print jobs.

NOTE: The information in this article also applies to the screen; however, this
issue more often impacts applications when printing, and therefore that is the
specific subject of this article.

CAUSE
=====

The application caches GDI objects by creating them and not deleting them until
the application terminates. Those objects are selected in and out of a printer
Device Context (DC) when needed, over the course of several print jobs.

GDI creates a new physical object structure for each logical object that is
selected into a printer DC. New physical objects are created even if the same
logical objects are selected into a different printer DC. Those physical objects
are not deleted until the corresponding logical objects are deleted. The more
objects used in printing, and the more jobs that are printed using those
objects, the more physical objects are created and more GDI resources are used
up.

RESOLUTION
==========

Do not cache GDI objects (such as pens, brushes, and fonts). Instead, create
them, use them during printing, and then delete them after each print job.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

MORE INFORMATION
================

This problem can be reproduced as follows:

1. Create a logical object such as a pen, brush, or font.

2. Repeat the following steps:

  a. Create a printer DC.

  b. Select the object into and out of the printer DC.

  c. Delete the printer DC.

With each iteration, GDI memory decreases.

Additional query words: buglist3.10 3.10 system resources

======================================================================
Keywords          : kbOSWin310 _IK kbSDKWin16 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Version           : WINDOWS:3.1
Issue type        : kbbug
Solution Type     : kbpending

=============================================================================

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.