PRB: midiInputHandler GP faults in MIDIMON Sample Application
Article ID: 100030
Article Last Modified on 7/14/2004
APPLIES TO
- Microsoft Windows Software Development Kit 3.0
- Microsoft Windows Software Development Kit 3.1
This article was previously published under Q100030
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 KB100030