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From: zben@umd5.UUCP
Newsgroups: net.unix-wizards
Subject: Re: Shared Memory
Message-ID: <824@umd5.UUCP>
Date: Tue, 24-Dec-85 18:19:22 EST
Article-I.D.: umd5.824
Posted: Tue Dec 24 18:19:22 1985
Date-Received: Thu, 26-Dec-85 03:54:17 EST
References: <830@brl-tgr.ARPA> <1188@princeton.UUCP>
Reply-To: zben@umd5.UUCP (Ben Cranston)
Organization: U of Md, CSC, College Park, Md
Lines: 15
Summary: Relative pointers, anyone?

In article <1188@princeton.UUCP> lrr@princeton.UUCP (Larry Rogers) writes:

>As I read your note, I pondered the problem of sharing linked lists between
>processes as the addresses stored in the data structures comprising the
>list items cannot have process-specific addresses unless the shared
>memory is placed at the same virtual location in each process.  ...

This may seem too obvious to mention, but if one keeps pointers RELATIVE to
some known location (like the beginning of the data structure in question)
then multiple processes can interpret the data structure regardless of its
position in the address space...
-- 
"We're taught to cherish what we have   |          Ben Cranston
 by what we have no longer..."          |          zben@umd2.umd.edu
                          ...{seismo!umcp-cs,ihnp4!rlgvax}!cvl!umd5!zben