On 8 April 2013 17:32, David Korn <[email protected]> wrote: > cc: [email protected] > Subject: Re: Re: Re: [ast-developers] ksh93 alpha update > -------- > >> The contra argument is that any person can do a kill -CHLD $victimpid >> and scripts should guard themselves against such actions. The 2nd >> contra argument is that scripts should use the output of the jobs >> builtin to check for changes - if there isn't any change then nothing >> should happen. >> >> > > The shell will ignores any CHLD that does not produce a change > in status for any process. > > It does check for STOP and CONTINUE but currently these do not > trigger the trap. I think that it makes sense to trigger the > trap in these cases, but my concern is backward compatibility. > I plan on trying to add these and see what breaks.
FYI a colleague found an innovative use of stop and continue for child processes: he implemented (using C and now he tries ksh93) a barrier mechanism. Each worker process completes a given task and then puts itself to sleep using the kill -STOP $$, for which the parent process (ksh93) gets the CHLD/stop trap as notification. The parent then wakes up the child when all child processes have reached the barrier. His question now is: Is there an API to send kill -CONT to all child processes - maybe via the process group? Ced -- Cedric Blancher <[email protected]> Institute Pasteur _______________________________________________ ast-developers mailing list [email protected] http://lists.research.att.com/mailman/listinfo/ast-developers
