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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,3a3dffa82925efee X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!news.glorb.com!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!elnk-atl-nf1!newsfeed.earthlink.net!stamper.news.atl.earthlink.net!newsread3.news.atl.earthlink.net.POSTED!d9c68f36!not-for-mail Message-ID: <40DDDFB8.2060103@noplace.com> From: Marin David Condic User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0 (OEM-HPQ-PRS1C03) X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Advantages References: <20040624170516.B4DFC4C4110@lovelace.ada-france.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Date: Sat, 26 Jun 2004 20:43:20 GMT NNTP-Posting-Host: 209.165.24.242 X-Complaints-To: abuse@earthlink.net X-Trace: newsread3.news.atl.earthlink.net 1088282600 209.165.24.242 (Sat, 26 Jun 2004 13:43:20 PDT) NNTP-Posting-Date: Sat, 26 Jun 2004 13:43:20 PDT Organization: EarthLink Inc. -- http://www.EarthLink.net Xref: g2news1.google.com comp.lang.ada:1938 Date: 2004-06-26T20:43:20+00:00 List-Id: I'm not sure what you want for statistical proof. In my experience with writing low-level software in an environment where I don't have an OS, I can say that the things that tend to cause the most difficult problems are where the software meets the hardware. Try to get two different CPUs synchronized across some communication link or deal with some I/O device where timing or synchronization are important to getting it right. Or sometimes its within the CPU instruction set itself - where arguments start about hardware vs software bugs. The *hard* stuff to get right is not related to bugs in type checking or constraint checking (or other language related stuff). Its the uncertainty of when things are happening or the fact that dozens of things are happening nearly all at once and corner conditions can come up that are difficult to test and difficult to program around. Tasking may help, but that is only built on the assumption that your tasking primitives down at the low level have no bugs. Try figuring out how to synchronize tasks across multiple processors and implement the full set of Ada requirements in that regard and it might give you an idea of how difficult that might be to get right. So I don't think that Ada automagically makes an OS "better" in some regard. Its going to have more to do with how sound the "Model" is for the lower level stuff - and even then, as you pile more and more layers on top ofit, you start discovering the limitations or design flaws in the model. I'm not saying someone can't do a better job with Ada - just that an OS is *really hard* to make stable and secure and it isn't something that can be done in a few weekends of coding and hope it will somehow be better. MDC Andrew Carroll wrote: >>------------------------------ >>Message: 6 >>From: "Nick Roberts" >>Subject: Improving Ada's Image >> >>"Marin David Condic" wrote in message >>news:40CEDEBB.3050209@noplace.com... >> >> >>>Like I said: The thing that makes operating systems hard to >>>get right are not usually language issues. They are related to >>>the asynchronicity of events and the complexity of the >>>algorithms involved. >> >>This is one of the biggest advantages of writing system software in > > Ada. > >>Quite a lot of the really nasty pitfalls associated with parallel >>programming in other languages are made either impossible or much more >>easily detected and debugged by Ada. > > > Okay Marin and Nick, I want to learn more. Where can I find the > statistical and practical proof? I'm not trying to snub your comments, > I just want to be able to provide the proof when I talk to my co-workers > about Ada. Thanks! > > -- ====================================================================== Marin David Condic I work for: http://www.belcan.com/ My project is: http://www.jsf.mil/NSFrames.htm Send Replies To: m o d c @ a m o g c n i c . r "Face it ladies, its not the dress that makes you look fat. Its the FAT that makes you look fat." -- Al Bundy ======================================================================