Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!usenet
From: bruner@sp15.csrd.uiuc.edu (John Bruner)
Newsgroups: comp.unix.wizards
Subject: Re: driver close from exit can't catch signal?
Message-ID: <1990Jul31.143028.20009@ux1.cso.uiuc.edu>
Date: 31 Jul 90 14:30:28 GMT
References: <26789@nuchat.UUCP> <18901@ttidca.TTI.COM>
Sender: usenet@ux1.cso.uiuc.edu (News)
Reply-To: bruner@sp15.csrd.uiuc.edu (John Bruner)
Organization: CSRD, University of Illinois
Lines: 15
In-Reply-To: mb@ttidca.TTI.COM (Michael Bloom)

In article <18901@ttidca.TTI.COM>, mb@ttidca (Michael Bloom) writes:
>I dealt with a problem somewhat like yours once with a test of the
>form "(u.u_signal[SIGKILL -1] == SIG_IGN)", which should only be true
>in your close routine if it is called from exit. I didn't really like
>it, but it did the job.

On (at least some) BSD systems, u.u_signal[SIGKILL-1] == SIG_IGN for
processes 1 and 2.  You can't ignore kill signals, but the kernel
initializes them this way when it spawns "init" and the pageout
daemon.  It seems unlikely that either of these will call a device's
close routine; however, beware of using this technique in other
situations.
--
John Bruner	Center for Supercomputing R&D, University of Illinois
	bruner@csrd.uiuc.edu		(217) 244-4476