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Subject: Re: cvs commit: src/sys/kern kern_event.c src/sys/sys eventvar.h
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On 14 Jul, Alfred Perlstein wrote:
> * Doug Rabson <dfr@nlsystems.com> [040714 12:01] wrote:

>> Seems to me that the best thing to do is to defer the psigio() to a 
>> taskqueue that will run in a simpler locking environment.
> 
> I was thinking that, but I'm worried about "stale delivery",
> perhaps we need to record the generation count (process start time)
> in the sigio as well as the request sent, so that we don't send
> a signal to the wrong process.

This is already handled in the sigio infrastructure.  Both struct proc
and struct pgrp have a list of their potential sigio sources. When the
process or process group goes away, the exit code disables sigio
delivery.