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Date: Thu, 10 Mar 2005 22:11:01 +0800
From: David Xu <davidxu@freebsd.org>
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To: Robert Watson <rwatson@freebsd.org>
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cc: Antoine Brodin <antoine.brodin@laposte.net>
Subject: Re: cvs commit: src/sys/kern uipc_sem.c
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Robert Watson wrote:

>So the question is -- will the parent process see any parallelism in
>kernel during fork() for any of our threading model, or do we prevent
>that?
>
>Robert N M Watson
>
>
>  
>
When fork1() running,  only the current forker thread can run,
other threads in same process are just suspended by the forker,
same as it it in exec().
I haven't looked uipc_sem.c, but as you said above, it seems
sem can be shared between processes, you'd care if A and B are
sharing same sem, but now B would like to fork a new child C,
not sure if you will have the problem within this condition.

David Xu