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	Tue, 27 Jan 1998 00:33:55 +1100
Date: Tue, 27 Jan 1998 00:33:55 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199801261333.AAA30019@godzilla.zeta.org.au>
To: dyson@FreeBSD.ORG, randy@covalent.net
Subject: Re: Cyclades/Hylafax/SMP select problems?
Cc: brian@worldcontrol.com, current@FreeBSD.ORG
Sender: owner-freebsd-current@FreeBSD.ORG
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>Seems that a change to open the FIFO O_RDWR solves the problem.
>Apparently, select() is returning when it should not be. This
>must be a new bug in select().

More likely, select() is returning when it should be.  Fifos used to
have a bug that caused them to hang (in the not-O_NONBLOCK case) for
all except the first read on a fifo with no writers.  select() should
have had bug for bug compatibility with read().  Now it should return
immediately if there are no writers.  O_RDWR might work around a bug
in hylafax by ensuring that there is always a writer.

Bruce