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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nntp.coast.net!dispatch.news.demon.net!demon!awfulhak.demon.co.uk!awfulhak.demon.co.uk!awfulhak.demon.co.uk!not-for-mail From: brian@awfulhak.demon.co.uk (Brian Somers) Newsgroups: comp.unix.bsd.misc Subject: Re: Comments on new 4.4 Design book? Date: 5 Jul 1996 14:14:17 -0500 Organization: Coverform Ltd. Lines: 28 Message-ID: <4rjpi9$hh@anorak.coverform.lan> References: <4rhnr0$lef@picasso.op.net> NNTP-Posting-Host: localhost.coverform.lan X-NNTP-Posting-Host: awfulhak.demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Bruce Momjian (root@candle.pha.pa.us) wrote: : I see that "The Design and Implementation of the 4.4 BSD Operating : System" was released in May of this year, and I haven't seen any : comments about it. (ISBN 0-201-54979-4) : Does anyone who has it want to comment on it? It's red and has the Daemon on the front, but apart from that I havn't read any yet. I'm still wading through "Unix Internals" by Valhalia. Has anyone any comments on that ? One of the exercises at the end of chapter 2 suggests that the PICs in a PC have no way of prioritizing interrupts. I'm sure I read that they did in PC-Intern. Also, there's a bit in chapter 3 - the one about threads that I think may cause problems. On page 69, Valhalia explains about the delivery of asyncronous interrupts. He suggests that if an "interrupt handling thread" blocks for some reason, it, and the user thread that was being run when the interrupt occured, can get re-scheduled seperately. This means that a signal handler is not guaranteed to happen "atomically" with respect to the users program..... I know that this could break a lot of code I've written over the years. I've always assumed that I can muck around with nasty data structures within the interrupt handler as long as I make sure they're in a good state when I enter the handler. -- Brian <brian@awfulhak.demon.co.uk> Don't _EVER_ lose your sense of humour....