1997 October 20

SIG_IGN Inheritance

Canada requests that the U.S. member body submit the following to the U.S. development body for review and comment and respond not later than the next WG15 meeting.

> Submitted-by:
> In this thread, I have suggested that UNIX standards be amended to prevent
> the inheritance of SIG_IGN as a SIGCHLD signal disposition.  I want to
> emphasize that this suggestion is not to affect any other signal.  Also,
> this would only be a relatively minor change to the semantics of exec()
> calls and their variants.
> In POSIX.1, because it does not sanction SIG_IGN as a SIGCHLD disposition,
> the effect of this change is to increase the likelihood that the initial
> environment a programme finds itself in after an exec() call conforms to
> POSIX.1.
> Upon further examination of UNIX98, I also suggest that the inheritance of
> the SA_NOCLDWAIT flag be prevented.  The effect of both suggestions on
> UNIX98 is to prevent an implementation from discarding zombie processes
> without the consent of the programme running in the parent process.  In
> addition, any such consent would need to be renewed after every exec()
> call the parent process makes.
> In both cases, the suggested changes are intended to eliminate a
> contradiction that exists between the standards and widespread practice.
> Because UNIX98 is essentially an evolution of Spec1170 and UNIX95, I doubt
> I need to bother with having them changed.  That said, what's my next
> step?  How do I go about starting the process to have POSIX.1 and UNIX98
> amended?  The web sites are not overly clear on this point.
> Thanks.
> --
> Marc Aurele La France           |  work:   1-403-492-9310
> Computing and Network Services  |  fax:    1-403-492-1729
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