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From: schlut@oski.toppoint.de (Olaf Schlueter)
Newsgroups: comp.os.minix
Subject: Re: Vi and alarm.
Message-ID: <4@oski.toppoint.de>
Date: 26 Mar 91 19:13:02 GMT
References: <2996@redstar.cs.qmw.ac.uk> <79@oski.toppoint.de>
Organization: Toppoint Mailbox
Lines: 23


So, thanks to Bruce Evans, I have to correct myself:

schlut@oski.toppoint.de (Olaf Schlueter) writes:
>You can watch the bug working in:
>   do { 
>      alarm(1); n = read (1,&c,1); alarm(0) } while( n > 0);
>}
>run this program and hold the "a" key pressed. In normal v7 Unix that
>programm will stop within a second after releasing "a". In Minix
>the program runs 1 second, whether you press "a" or not.

I've been wrong :-( This simple version fails as for the buffering read.
If you set RAW-Mode (and by the way read from stdin rather
then stdout, bad typ-O), everything works as expected from v7 unix.

Bruce thinks, there is a race condition, the alarm may expire after the
read, but before the alarm(0) call - this would explain, why it is
only seen on slow machines.

-- 
Olaf Schlueter, Sandkuhle 4-6, 2300 Kiel 1, FRG, schlut@oski.toppoint.de
"Someone is always the evil in the land, and hhhcor:
:
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