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Subject: Re: Desperately missing a working "pselect()" or similar...
To: neilb@cse.unsw.edu.au (Neil Brown)
Date: Sat, 6 Oct 2001 01:03:04 +0100 (BST)
Cc: alex@pennace.org (Alex Pennace), ecki@lina.inka.de (Bernd Eckenfels),
        linux-kernel@vger.kernel.org
In-Reply-To: <15294.16536.430907.650513@notabene.cse.unsw.edu.au> from "Neil Brown" at Oct 06, 2001 09:22:00 AM
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
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> A technique I used in a similar situation once went something like:
> 
> tv.tv_sec=bignum;
> tv.tv_usec = 0;
> enable_signals();
> select(nfds, &readfds,&writefds,0,&tv);
> 
> and have the signal handlers set tv.tv_sec to 0. (tv is a global
> variable).
> 
> Then if the signal comes before the select, the select exits
> immediately.

You can do this more cleanly with sigsetjmp - it avoids any risk of suprises
in the library itself - eg the select to poll mapper in some libraries - and
indeed even the variable load into registers for a syscall
 
-
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