Path: news.daimi.aau.dk!olm From: olm@daimi.aau.dk (Ole Lehrmann Madsen) Newsgroups: comp.programming.threads,comp.lang.beta Subject: Re: Threads in programming languages Date: 24 Oct 1995 22:26:19 GMT Organization: DAIMI, Computer Science Dept. at Aarhus University Lines: 61 Message-ID: <46jp6b$7m8@krone.daimi.aau.dk> References: <46j04s$p2o@whitbeck.ncl.ac.uk> NNTP-Posting-Host: clematis.daimi.aau.dk Xref: news.daimi.aau.dk comp.programming.threads:75 comp.lang.beta:10533 I agree completely with Ron that most OO languages are missing an important dimension with reespect to threads. Beta is one of the successors to Simula that have 'inherited' the notion of active objects. In addition to the coroutines of Simula, Beta has built-in concurrency. In the current implementation of Beta true concurrency is supported through the implementation of distributed objects. A forthcoming version will support preemptive scheduling within a single process. If you are interested in more information about Beta, check the following sources or send me e-mail. Ole Lehrmann Madsen *************** BETA information Sources *********************************** WWW: http://www.mjolner.dk http://www.daimi.aau.dk/~beta/info News: comp.lang.beta FAQ: http://www.daimi.aau.dk/~beta/FAQ E-mail: info@mjolner.dk Address: Mjolner Informatics, Science Park Aarhus, Gustav Wieds Vej 10, DK-8000, Aarhus C, DENMARK Tel.: +45 86 20 20 00 Fax.: +45 86 20 12 22 ***************************************************************************** Thus spake "R. Kerr" : >I'm glad to see this interest in threads for the following reason. >I have had a close connection with the SIMULA programming language since >1968. As its name suggests, SIMULA has its roots in simulation but is in >fact a truly general-purpose high-level language. SIMULA is generally >considered to have been the first object-oriented language. It laid down >virtually all the agreed principles of object-orientation and all >object-oriented products are derived from it in some way. >Strangely, although adopting SIMULA's notions of class/object, >inheritance, dynamic binding, etc., most (but not quite all) newer >languages ignored what I term "the missing dimension of OOP" - that of >autonomous objects, objects with their own threads of control. In SIMULA, >this notion manifests itself in "quasi-parallel systems" (coroutines). >SIMULA included this initially because it gives a superior framework for >simulating coherent processes but, of course, this can be used to >encapsulate any set of activities which are tightly bound to each other in >the process sense. >Maybe the interest shown in this newsgroup will have some influence in >making language designers question just why this aspect of software >architecture has been deliberately rejected in the popular programming >languages. >Cheers....Ron >P.S. SIMULA is still alive and kicking. It is still one of the best >vehicles for learning the principles of object-orientation and, as I >assert above, is more complete than most. If anyone is interested in >SIMULA, I would be happy to provide information and references. >P.P.S. The 21st annual SIMULA conference was held last week.