Re: busyloop in sigchld_handler

[Andreas Schwab]

David Kastrup <address@hidden> writes:

> Andreas Schwab <address@hidden> writes:
>
>> If you don't use WNOHANG you open up a race where several processes may
>> have their status changed, but only one signal is sent (non-realtime
>> signals are not queued).
>
> How does WNOHANG protect against that?

It makes it possible to loop around without blocking.  On system without
WNOHANG there needs to be other mechanisms to garantee one signal per
child (they probably redeliver the signal as long as such children exist).

Andreas.

-- 
Andreas Schwab, SuSE Labs, address@hidden
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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