Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!yetti!geac!daveb From: daveb@geac.UUCP Newsgroups: comp.arch,comp.unix.wizards,comp.os.misc Subject: Re: A Shared Libraries Solution Message-ID: <1629@geac.UUCP> Date: Sun, 18-Oct-87 10:58:48 EDT Article-I.D.: geac.1629 Posted: Sun Oct 18 10:58:48 1987 Date-Received: Mon, 19-Oct-87 19:35:29 EDT References: <1057@unicus.UUCP> <400@nuchat.UUCP> Reply-To: daveb@geac.UUCP (Dave Collier-Brown) Organization: The little blue rock next to that twinkly star. Lines: 33 Keywords: error detection heuristic Xref: yetti comp.arch:2488 comp.unix.wizards:4598 comp.os.misc:283 In article <400@nuchat.UUCP> steve@nuchat.UUCP (Steve Nuchia) writes: >In article <1057@unicus.UUCP>, craig@unicus.UUCP (Craig D. Hubley) writes: >> program will try the new one, fail, back up to the error (if possible), >> or restart if not, and ask you to make the old one available. > >Does this not beg the question of how the program _detects_ the failure? > ... >I think I understand you to be saying that your approach allow the system >to run in the presence of a new, untested library? How does this differ >(in the light of the sequel) from the "old way" ? One technique actually used was to have a human detect certain errors by running with "EXperimental_Library" in his search path before the tested libraries. If a program-detectable error (a mismatch, in practice) occurred, she got an error message. If she detected an error herself or received a message, she contacted the author of the library or the system administrator (since that was easy) before setting up a special referencing domain for the program (which was not so easy, but at least possible). Humans would actually use >exl in their search paths, to be sure of getting the newest versions of things. Even I did. There were other support facilities underneath the human tester, obviously. The most important was a translate-to-different-version routine that the author of the new, improved library was required to write for each incompatible data-structure of file-format change. --dave (I was discussing Mutlics, you understand) c-b -- David Collier-Brown. {mnetor|yetti|utgpu}!geac!daveb Geac Computers International Inc., | Computer Science loses its 350 Steelcase Road,Markham, Ontario, | memory (if not its mind) CANADA, L3R 1B3 (416) 475-0525 x3279 | every 6 months.