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Q199517: PRB: FreeResource Required for Locked Resources on Macintosh

Article: Q199517
Product(s): Microsoft C Compiler
Version(s): MACINTOSH:2.0,4.0,4.0b
Operating System(s): 
Keyword(s): kbHWMAC kbMFC kbVC200 kbVC400 kbGrpDSMFCATL kbNoUpdate
Last Modified: 11-MAR-2000

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The information in this article applies to:

- Microsoft Visual C++, Macintosh Cross-Development Addon, versions 2.0, 4.0, 4.0b 
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SYMPTOMS
========

Not calling FreeResource may cause Macintosh applications to leak memory.

CAUSE
=====

Resources on the Macintosh are fairly similar to Windows resources, but there
are a few differences.

In Win32 applications, resources do not have to be locked or freed. On Macintosh
platforms, however, calling LockResource does actually lock a memory block in
the heap. Not calling FreeResource causes that block to remain locked.

RESOLUTION
==========

To avoid memory leaks and heap fragmentation, FreeResource must be used on the
Macintosh when a resource loaded using LoadResource is no longer needed.

REFERENCES
==========

Macintosh Porting Guide: Resource Differences

Additional query words: FreeResource LockResource UnlockResource memory leak heap fragmentation

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Keywords          : kbHWMAC kbMFC kbVC200 kbVC400 kbGrpDSMFCATL kbNoUpdate 
Technology        : kbVCsearch kbHWMAC kbOSMAC kbAudDeveloper kbVCXDev200Mac kbVCXDev400Mac kbVCXDev400bMac
Version           : MACINTOSH:2.0,4.0,4.0b
Issue type        : kbprb

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