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From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.unix.questions
Subject: Re: How does one imitate SV_INTERRUPT?
Message-ID: <16432@smoke.brl.mil>
Date: 17 Jun 91 14:08:24 GMT
References: <13619@mentor.cc.purdue.edu> <11847.Jun1621.03.3791@kramden.acf.nyu.edu>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 15

In article <11847.Jun1621.03.3791@kramden.acf.nyu.edu> brnstnd@kramden.acf.nyu.edu (Dan Bernstein) writes:
>In article <13619@mentor.cc.purdue.edu> woodcock@mentor.cc.purdue.edu (Bruce Sterling Woodcock) writes:
>> The subject basically says it all.  I'm programming on a Sequent Symmetry
>> using Dynix V3.0.12 which, unfortunately, doesn't support the SV_INTERRUPT
>> flag.  Most systems after 4.2BSD have it.  To quote a 4.3BSD manual page:
>One of BSD 4.2's biggest failures was forcing system calls to restart;
>there are just too many applications where EINTR can't be ignored.

I missed the start of this discussion, but it may be worth pointing out
that my "BRL UNIX System V emulation for 4.2BSD" solved this problem by
an amazing kludge, which I could have sworn that the Dynix System V
environment picked up, that recovers the pre-4.2BSD behavior for
interrupted "slow I/O" system calls.  If Bruce would like to try it, he
can drop me a note (Gwyn@BRL.MIL) and I'll send my signal() emulation
that implements this kludge.