From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,FREEMAIL_FROM, INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,a5681531ca1cf09e X-Google-Attributes: gid103376,public From: pascmartin@aol.com (PascMartin) Subject: Re: Tasking performance between Ada83 and Ada95 Date: 1997/06/10 Message-ID: <19970610080401.EAA18524@ladder02.news.aol.com>#1/1 X-Deja-AN: 247392974 References: Organization: AOL http://www.aol.com Newsgroups: comp.lang.ada X-Admin: news@aol.com Date: 1997-06-10T00:00:00+00:00 List-Id: Robert Dewar wrote: "That's my guess too. I very much doubt that the Alsys World compiler on HPUX used system level threads, and I also guess that the version of GNAT on HPUX is probably using DCE threads. So the comparison is completely meaningless." I don't agree. Let me elaborate. First, a few comments: - to my knowledge there is _no_ thread support in the HP-UX kernel (9 months ago..). - the DCE thread library is an user-level thread simulation (same comment). - the AdaWorld product use "proprietary" user-level thread simulation, built into the Ada runtime, and (obsessively) optimized for it. So far, considering respective features of these two runtimes, I see no difference. Both are switching tasks at the same user level. Both will have the same problems regarding blocking IOs, both will never take benefit of multiprocessing, etc.. Back to the point, can you compare a bicycle and a Ford Mustang?. No, of course.. Robert you should practice bicycle more often, for me I can tell the difference when I use one or the other :-) (BTW, bicycle enhance breathing). What I want to demonstrate is: if the benchmark reflects the user's need, then the benchmark is good. It does not matter what products are compared, as all Ada compilers implement the same thing: the Ada language. Don't they ? If there is a better runtime for GNAT on HP-UX, this is a good time to disclose it. If there is none, the comparison seems valid to me. It is true Ada95 ATC is a major constraint for runtime developpers. As robustness is critical, especially in the first releases of a product, I expect most Ada95 runtimes to take a hit compare to Ada83 ones (1). Beside that, ATC is so complicated that most (sane) people will probably avoid using it. My conclusion is: some Ada95 new features could have been left on the side; they are appealing to a minority, and appaling to the others. To conclude, if some program has to be developped for the real world, and Ada83 is good enough, why not selecting AdaWorld?. When Ada95 (and GNAT) will have been well optimized, or when HP will have released the 1 GHz HPPA workstation (which ever come first), it will be time to switch. BTW, I must disclose that I have been working in Alsys for more years that I want to admit.. (1) except for some implementation details. The ObjectAda runtime includes a secondary stack design that is refreshingly efficient. Tucker Taft brain child.. Pascal.