stop a procedure execution in GTK

[447158 celes unizar es]

Hi,

  I'm programming an application using GTK+1.2.  I have to execute a procedure
(for instance as a callback when clicking on a "start" button) and then I'd like
to be able to stop it whenever the user gets bored (for instance by having
another button "stop").  However I suppose that if a callback procedure is
executed it cannot stop and of course it would not allow the application to
catch new events till it's finished, or yes?

  I'd never found this situation, and maybe I am talking about a simple and
basic topic in GTK or about an impossible thing, I don't know.  Or maybe it's
too late and my brain doesn't work properly... 

  By the way, ideas and suggestions are wellcome.

  Thanks,

    Germán Latorre Antín