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Article #5877Re: DOS re-entrancy
From: Geoff Arnold
Date: Tue, 04 Mar 1986 15:07
Date: Tue, 04 Mar 1986 15:07
16 lines
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1495 bytes
The obvious solution (so obvious it's gonna be posted umpteen times):
grab the int21 vector yourself, and set an "indos" flag when a user call
comes in. Your driver then checks "indos" on interrupt: if set, it
sets "servicewanted" and lets DOS continue; otherwise it just performs
the required activity (including int21's).. On the way out, DOS returns
to your int21 interceptor, which clears "indos" and (if "servicewanted"
is set) does the necessary servicing. You get the idea. The only
real complication is that you probably want to get the interceptor
out of the way while the service code is running.....
--
#include <sys/disclaimer.h> /* co. lawyers: will this do? */
Geoff Arnold, Sun Microsystems Inc. (East Coast Division)
SnailMail: One Cranberry Hill, Lexington, MA 02173; 617-863-8870 x136
UUCP: [East Coast] linus!security!sunne!suneast!geoff
[West Coast] {hplabs,ihnp4,nsc,pyramid,decwrl}!sun!suneast!geoff
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83 SMI; site suneast.uucp Path: arc1-ca.pugleaf.net!utzoo!linus!security!sunne!suneast!geoff From: geoff@suneast.uucp (Geoff Arnold) Newsgroups: net.micro.pc Subject: Re: DOS re-entrancy Message-ID: <137@suneast.uucp> Date: Tue, 4-Mar-86 10:07:07 EST Article-I.D.: suneast.137 Posted: Tue Mar 4 10:07:07 1986 Date-Received: Sat, 8-Mar-86 07:09:54 EST References: <103@nvuxr.UUCP> Organization: Sun Microsystems Inc. - East Coast Division Lines: 16