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From: ebergman@isis.cs.du.edu (Eric Bergman-Terrell)
Newsgroups: comp.windows.ms.programmer
Subject: Error Handling in Windows Programs
Message-ID: <1991Jun3.025142.4227@mnemosyne.cs.du.edu>
Date: 3 Jun 91 02:51:42 GMT
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Reply-To: ebergman@isis.cs.du.edu (Eric Bergman-Terrell)
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I'm currently adding error handling code to my Windows program (an astronomy
simulation/prediction/graphing program, for what it's worth).  I've added
code to handle the obvious problems, for example:

cannot find file
printer hasn't been specified
printer won't do graphics

But I'm wondering how to handle some non-obvious things.  So heres' a list of
questions:

1.	Are Catch() and Throw() reasonable to use when one of your program's
	commands has failed and you want to go back to the main event loop?

	For example, your main event loop calls a routine that calls a 
	routine that calls a routine that ,..., calls a routine that fails
	and you just want to quit what you're doing and let the user make
	another menu selection.

	In other words, are Catch() and Throw() reasonable to use & safe?
	What are the non-obvious pitfalls???

2.	I am dreading having to check the error codes from every single
	Windows function that my (30,000 line) program calls.  Are there
	alternatives that will still catch every failure?  For example, 
	is there a mechanism that would "call the specified function if
	failure X occurrs".

	For example, my program is graphically intensive.  It would be way
	cool to give Windows the address of a function to call whenever a
	request for a handle to a new gdi object failed...  

By the way, I have Petzold, Prog. Ref. and Guide to Programming.  I looked
in vain for coverage of error handling (beyond testing the results of evry
function call).  If I missed anything, just send me a page number!


Terrell