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: 103376,56250291936154a0 X-Google-Attributes: gid103376,public From: Ole-Hjalmar Kristensen Subject: Re: Where is the elusive jump command? Date: 2000/04/06 Message-ID: #1/1 X-Deja-AN: 607442816 Sender: ohk@gong2.clustra.com References: <38D771CA.D41AF9B5@port.ac.uk> <8bq7ku$mc8$1@nnrp1.deja.com> <38E0E723.C39C392@quadruscorp.com> <8brfm4$4uc$1@nnrp1.deja.com> <8brn4k$p6i$1@slb0.atl.mindspring.net> <8brrpj$i04$1@nnrp1.deja.com> <38E312F8.78883ACB@icn.siemens.de> <8c4rvf$d9k$1@nnrp1.deja.com> <2000Apr5.070127.1@eisner> X-Complaints-To: abuse@telia.no X-Trace: news.telia.no 955007992 195.204.160.194 (Thu, 06 Apr 2000 09:59:52 CEST) Organization: Telia Internet Public Access NNTP-Posting-Date: Thu, 06 Apr 2000 09:59:52 CEST Newsgroups: comp.lang.ada Date: 2000-04-06T00:00:00+00:00 List-Id: kilgallen@eisner.decus.org (Larry Kilgallen) writes: > In article , Ole-Hjalmar Kristensen writes: > > Robert Dewar writes: > > >> But in any case, binding to C is hardly a topic that is > >> appropriate to people first learning the language! > >> > > > > Certainly, but writing bindings to C is one of the first things you > > have to do if you start using Ada for systems programming on Unix, > > unfortunately. > > I am not sure what you mean by "systems programming" in this case. > I would presume that writing device drivers requires knowledge of > internal data structures, but don't vendors like Rational supply > bindings to Unix entrypoints that might be called by user-mode > programs ? I was not thinking device drivers, but systems like communications systems or DBMS's, which typically will need access to Unix entrypoints or system calls. A thick binding designed by someone who is unaware of the specific needs of the system may not be suitable. An example of the the need for system calls: A couple of months ago I wanted to test various implementations of asynchronous IO (Sun asynchronous IO, POSIX asynchronous IO, and Ada). However, to do a meaningful test, I need to ensure that I/O operations on the file descriptor complete as defined by synchronized I/O data integrity rules. This means either using the fcntl or fsync system calls, or setting the O_SYNC flag in the call to open. In this case, needing only a few system calls, it may be more cost effective to write your own binding, as it's usually not difficult. Yes, it may be possible to buy such a binding, although I have not seen any reference to it, either on Rational's web pages, nor on Adahome's list of bindings. There is a reference to a POSIX binding, but that seems very much to be a work in progress. Ole-Hj. Kristensen -- E pluribus Unix