Re: When do cleanups happen?

["Eli Zaretskii" <eliz@is.elta.co.il>]

> Date: Wed, 09 Jan 2002 19:36:36 -0500
> From: Andrew Cagney <ac131313@cygnus.com>
> > 
> > Hmm!  Now I am confused.
> > 
> > What do others think?  Are cleanups cleaned-up only on error?
> > Or always when a command finishes?  I know that I have found 
> > that if I make a cleanup that closes a file, then I cannot close
> > that file myself else it will wind up being closed twice.
> 
> Two styles:

Andrew, if Michael got confused by this, our docs needs work.  So I
suggest to add the nice explanations below to gdbint.texinfo, as the
first step towards a remedy.  There's a section about cleanups there
where these explanations will fit nicely.

> 	oc = make_cleanup (close, fd); // yes ok that is bad
> 
> 	....blah blah
> 
> 	do_cleanups (oc);
> 
> which always does the close using the cleanup.  This is kind of like a 
> TRY ... FINALLY .. END construct;
> 
> 	oc = make_cleanup (close, fd); // ...
> 	... blah blah
> 	discard_cleanups (oc);  //* is that the right f name?
> 	... blah blah
> 	close (fd);
> 
> which discards the cleanups so you're free to do the close.  This is 
> kind of a TRY ... EXCEPT ... END.
> 
> And then there is the truth:
> 
> catch_exceptions() / catch_errors() does a cleanup.
> 
> the main command loop has a do_cleanup() call.
> 
> enjoy,
> Andrew
> 
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