From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <88f3a9a7b4b349bbc153cae9e1f0dfde@felloff.net>
Date: Thu,  2 Jan 2014 23:53:24 +0100
From: cinap_lenrek@felloff.net
To: 9fans@9fans.net
In-Reply-To: <14d36fdb195faa18bbf2f6b28553cdaa@mikro>
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Subject: Re: [9fans] devproc noteid changing for none
Topicbox-Message-UUID: ab6e8674-ead8-11e9-9d60-3106f5b1d025

no. the debug qlock is so the process wont exit. once you hold it,
the process might be running, might be in the process of exiting
might have been already exited or might have been reused.

the key here is that while you hold it. it wont make it to the
process freelist when not already there. it wont change
from "exiting -> exited". but it wont prevent it from being
reused when it was exited already... but...

pexit() zeros p->alarm. and p->alarm can not be set to non-zero
value again while we hold the alarms qlock in the kproc!

so this actually works.

--
cinap