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: 103376,894846be18e92713 X-Google-Attributes: gid103376,public From: "Theodore E. Dennison" Subject: Re: GNAT R/T Annex and Win95 Date: 1996/04/22 Message-ID: <317BC037.1CFBAE39@escmail.orl.mmc.com>#1/1 X-Deja-AN: 150825682 references: <96041916380674@psavax.pwfl.com> content-type: text/plain; charset=us-ascii organization: Lockheed Martin Information Systems mime-version: 1.0 newsgroups: comp.lang.ada x-mailer: Mozilla 2.0 (X11; I; SunOS 4.1.3_U1 sun4m) Date: 1996-04-22T00:00:00+00:00 List-Id: Marin David Condic, 407.796.8997, M/S 731-93 wrote: > > Here's an interesting question which we've been thinking about > around here a lot: > > Do you consider Windows NT capable of being a "realtime" operating > system? (It doesn't seem to be advertised as such.... yet.) > A straight NT question in an Ada group, huh? Oh well... When you say "real-time", typically I think of a system with a clock which is capable of generating software iterrupts every 10msec or better, and some way of knowing when you have failed to service an interrupt. According to my NT book, there are two ways to do Timers with NT. The first uses the SetTimer system call. This will put a WM_TIMER event in the thread's normal message queue. The resolution is ABOUT 55 milliseconds, but there can be message queue delays. Not very useful. The second is the "Multimedia Timer". This timer allows you to define a callback that will get called directly by an interrupt, without any message queue processing overhead. The resolution is said to be "about 16 (Intel) milliseconds". Whatever that means, you can get the exact resolution on your system via a call to "timeGetDevCaps". (Oddly enough, Microsoft's example uses a resolution of 5 milliseconds) This is a little more useful, but still not what we would like to see. -- T.E.D. | Work - mailto:dennison@escmail.orl.mmc.com | | Home - mailto:dennison@iag.net | | URL - http://www.iag.net/~dennison |