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,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,956e1c708fea1c33 X-Google-Attributes: gid103376,public From: stt@houdini.camb.inmet.com (Tucker Taft) Subject: Re: Looking for implementation idea Date: 1999/02/07 Message-ID: #1/1 X-Deja-AN: 441748253 Sender: news@inmet.camb.inmet.com (USENET news) X-Nntp-Posting-Host: houdini.burl.averstar.com References: Organization: Intermetrics, Inc. Newsgroups: comp.lang.ada Date: 1999-02-07T00:00:00+00:00 List-Id: Corey Minyard (minyard@acm.org) wrote: : ... : One question for the Ada experts: Ada protected types don't work in : SMP since they are task priority based, do they? Ada protected types *do* work on a multi-processor. They boost the priority to prevent unbounded priority inversion, not to lock. On a mono-processor, it turns out that boosting the priority is sufficient to accomplish mutual exclusion. On a multiprocessor, the protected type will also need to acquire a (probably spin) lock. : ... Or maybe I'm missing : something. If they don't, maybe we should think about adding a real : semaphore to the Ada spec. No need. Protected types do the job, in a way that is independent of the number of physical processors. I'm curious -- where did you get the impression that protected types did not work on a multiprocessor? I'm wondering how common is this misconception... : -- : Corey Minyard Internet: minyard@acm.org : Work: minyard@nortelnetworks.com UUCP: minyard@wf-rch.cirr.com -Tuck -- -Tucker Taft stt@averstar.com http://www.averstar.com/~stt/ Technical Director, Distributed IT Solutions (www.averstar.com/tools) AverStar (formerly Intermetrics, Inc.) Burlington, MA USA