Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!oz From: oz@yunexus.yorku.ca (Ozan Yigit) Newsgroups: comp.lang.lisp Subject: Re: Memory Management in Lisp? Message-ID: <21797@yunexus.YorkU.CA> Date: 2 Mar 91 04:43:36 GMT References: <1991Feb15.191259.20090@aero.org> <1991Feb15.223520.17267@Think.COM> <1991Feb18.191549.7575@aero.org> <1991Feb19.030719.1137@Think.COM> Sender: news@yunexus.YorkU.CA Organization: York U. Communications Research & Development Lines: 32 In article jinx@zurich.ai.mit.edu writes: [quoting Piercarlo Grandi] > > To rely on garbage collection, which is a worst case mechanism to use to > reclaim storage when nothing is known a priori about value lifetime, for > known lifetime cases is clearly wasteful. An analogy is using dynamic > type dispatching when the type of a value is well known by design. Maybe > we need sophisticated, checkable lifetime declarations (better than > DYNAMIC-EXTENT), not just sophisticated, checkable, type declarations. > > >Hmm. So you would argue for programming with overlays rather than >using a virtual memory system? Or having programmers think about disk >sectors, head motion, and queueing operations on the disk rather than >using the OS-supplied facilities that hide such details. This must be the usual gang-up-on-Piercarlo week ;-) I think your interpretation makes Piercarlo's views appear much more radical than they actually are. Heck, you know the type of analsis that goes into scheme compilers [for example] to avoid heap allocation [McDermott, Dybvig etc] better than I do. Aren't nemory allocation strategies based on lifetimes [Hanson] and Generational GC mechanisms are in essence use exactly the idea of making use of some knowledge about the extent of things? [Do weak references count as a similar mechanism?] So, what is so offensive about his suggestions? oz --- In seeking the unattainable, simplicity | Internet: oz@nexus.yorku.ca only gets in the way. -- Alan J. Perlis | Uucp: utai/utzoo!yunexus!oz