Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!mailrus!ncar!gatech!hubcap!billwolf%hazel.cs.clemson.edu From: billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu (William Thomas Wolfe,2847,) Newsgroups: comp.sw.components Subject: Re: Inheritance vs. component efficiency Message-ID: <6254@hubcap.clemson.edu> Date: 12 Aug 89 23:06:42 GMT References: <130200005@p.cs.uiuc.edu> Sender: news@hubcap.clemson.edu Reply-To: billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu Lines: 26 From article <130200005@p.cs.uiuc.edu>, by johnson@p.cs.uiuc.edu: > [repost of an old article] I think we've pretty well beaten this topic to death in this newsgroup, and I see no point in reposting OLD articles to which I have already responded. There was a followup to my reply which I should have responded to, but did not, so I'll go ahead and cover it now: I mentioned that the situation which Ralph cited as one in which run-time binding was appropriate was one in which tasking would be sufficient, and Ralph said that this was overkill. But Ralph assumes a lot about how the multitasking will be implemented, which is entirely inappropriate. Hilfinger and others have done work on compiler technology which automatically converts certain Ada multitasking situations into systems which perform equivalently with fewer threads of control. Ralph also assumes that task creation will be a high-overhead situation; however, this is a characteristic of certain *operating systems*, not a characteristic of Ada. Work is also being done on "Ada engines", systems which are specifically designed to, among other things, provide the support for lightweight processes that is appropriate for an Ada environment. I will have more to contribute on this topic when I return from the Tri-Ada '89 conference, at which reuse is going to be a major topic. Bill Wolfe, wtwolfe@hubcap.clemson.edu