KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q100030: PRB: midiInputHandler GP faults in MIDIMON Sample Application

Article: Q100030
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.0,3.1
Operating System(s): 
Keyword(s): kb16bitonly
Last Modified: 05-NOV-1999

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

- Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1 
-------------------------------------------------------------------------------

SYMPTOMS
========

In the MIDIMON sample application provided with Visual C++ and the Microsoft
Windows Software Development Kit (SDK) version 3.1, the midiInputHandler()
callback function causes a general protection (GP) fault.

CAUSE
=====

The GP fault occurs when the MIDI event handler tries to store event data in a
static variable, but the data segment (DS) is not set correctly because the
exported functions in the callback dynamic-link library (DLL) are not exported
correctly.

RESOLUTION
==========

Because the /GD compiler option is specified in the makefile for MIDIMON's
callback DLL, the DLL's exported functions must be declared with the __export
keyword. The exported functions missing the __export keyword are _WEP(),
midiInputHandler(), and PutEvent(). The __export keyword should be added as
required in CALLBACK.H and CALLBACK.DEF.

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

The problem described above exists only in the version of MIDIMON distributed
with Visual C++ (Microsoft C version 8.0); the original version distributed with
C 7.0 builds correctly as shipped.

Additional query words: 3.10 gp-fault gpf midi

======================================================================
Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version           : WINDOWS:3.0,3.1

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

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.