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=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,d3ac444cc1efa302 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-09-25 12:56:48 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!headwall.stanford.edu!newshub.sdsu.edu!elnk-nf2-pas!newsfeed.earthlink.net!newsfeed.news2me.com!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.arcor-online.net!newsfeed.r-kom.de!newsfeed.stueberl.de!proxad.net!usenet-fr.net!enst.fr!melchior!cuivre.fr.eu.org!melchior.frmug.org!not-for-mail From: "Beard, Frank Randolph CIV" Newsgroups: comp.lang.ada Subject: RE: Penalty of calling a protected operation or task-entry. Date: Thu, 25 Sep 2003 15:54:12 -0400 Organization: Cuivre, Argent, Or Message-ID: NNTP-Posting-Host: lovelace.ada-france.org Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Trace: melchior.cuivre.fr.eu.org 1064519692 8571 80.67.180.195 (25 Sep 2003 19:54:52 GMT) X-Complaints-To: usenet@melchior.cuivre.fr.eu.org NNTP-Posting-Date: Thu, 25 Sep 2003 19:54:52 +0000 (UTC) To: Return-Path: X-MimeOLE: Produced By Microsoft Exchange V6.0.6375.0 content-class: urn:content-classes:message Thread-Topic: Penalty of calling a protected operation or task-entry. Thread-Index: AcODnOpy4ckgr77dT2mT2KOXJGL61AAAIwwA X-OriginalArrivalTime: 25 Sep 2003 19:54:12.0726 (UTC) FILETIME=[CAD0D160:01C3839E] X-Virus-Scanned: by amavisd-new-20030616-p5 (Debian) at ada-france.org X-BeenThere: comp.lang.ada@ada-france.org X-Mailman-Version: 2.1.2 Precedence: list List-Id: Gateway to the comp.lang.ada Usenet newsgroup List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Xref: archiver1.google.com comp.lang.ada:42930 Date: 2003-09-25T15:54:12-04:00 -----Original Message----- From: tmoran@acm.org=20 >> As I have understood there is a time-penalty when calling a protected >> operation or task-entry. Im thinking about adminstrative cost > Have you profiled your program and found that the protected > operations are the bottleneck? >> Is there some approach to remove penalty from the "read" operation? > If another task is doing a Write, then Read will have to suffer the > penalty of waiting. If not, then it depends on how efficient is your > particular system's implementation. To add to what Tom said, we've never had the task-entry rendezvous become enough of a time-penalty to cause us any problems. Protected types were partially created/implemented to alleviate the "penalty" of the rendezvous. So use a protected type if it fits your design. Besides, what's your alternative if you need protected operations. Protected types are at least as fast, or faster, than going to an OS level semaphore. Frank