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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!feeder.eternal-september.org!news.linkpendium.com!news.linkpendium.com!news.snarked.org!border2.nntp.dca1.giganews.com!nntp.giganews.com!buffer2.nntp.dca1.giganews.com!buffer1.nntp.dca1.giganews.com!news.giganews.com.POSTED!not-for-mail NNTP-Posting-Date: Sat, 09 Mar 2019 12:46:16 -0600 Subject: Re: Why couldn't an operating system be written in ada Newsgroups: comp.lang.ada References: <4s8rud$9j3@tribune> <792fba1b-7a54-4d00-ae85-e6bd0737f001@googlegroups.com> From: Norman Worth Date: Sat, 9 Mar 2019 11:46:13 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0 SeaMonkey/2.49.4 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Message-ID: <5M-dnc3wFphllBnBnZ2dnUU7-WnNnZ2d@giganews.com> X-Usenet-Provider: http://www.giganews.com X-Trace: sv3-oOV5A/JzS27MoHf++5lTbfcotPv8UdBt1gQfaClpbfraBUZdSAvUpBGlsVzqJV8+Wc7Ld+JjN6Oncbp!JbxB5qCM5+C9OQiEivLuTI5oI7+XIcxvqsz0f/ArQRyupY7cQpoyWMB+XHLrGnLXgjIRuR+psHtp X-Complaints-To: abuse@giganews.com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 3913 Xref: reader01.eternal-september.org comp.lang.ada:55822 Date: 2019-03-09T11:46:13-07:00 List-Id: lyttlec wrote: > On 2/26/19 4:30 AM, Dmitry A. Kazakov wrote: >> On 2019-02-26 09:46, Niklas Holsti wrote: >>> On 19-02-25 23:56 , Rabican wrote: >>>> On Saturday, July 13, 1996 at 3:00:00 AM UTC-4, Mark  McKinney wrote: >>>>> It has been claimed that the capability to interface with other >>>>> languages >>>>> is a great asset to ada. Sometimes interfacing can be a tremendous >>>>> liability. Besides the OS could perform most of work that the language >>>>> runtime does. So why not build an OS in ADA? >>>> >>>> yeah why not?  anything? >>> >>> This has been discussed many times before in comp.lang.ada. >>> >>> The first question is not "why not build an OS is Ada", the first >>> question is "why build a new OS at all"? >>> >>> Then, if a new OS is going to be built for some reason, we can ask >>> which language should be used, and of course (IMO) Ada would be a >>> strong contender. However, for larger systems, the OS must usually >>> implement a "process" concept that goes beyond Ada tasking and >>> provides isolation between different users and applications. This >>> means that the OS will have a process/service-level API that is not, >>> as such, Ada-language specific. And so the fact that the OS is >>> implemented in Ada becomes invisible on the application level. >>> >>> This is not to say that an OS API specified in Ada could not be an >>> improvement (for Ada applications) on the current OS APIs which are >>> usually specified in C. However, such an Ada OS API could also be >>> provided for an OS implemented in C or some other language. >> >> Right. This is a general problem only tangentially related to Ada. The >> purely procedural OS API outlived their time. >> >> A new generation of OSes must have higher-level API which would include >> tasking and synchronization primitives as well as other abstract types >> types. Call it OO or not, but that is beyond procedures, ints and void *. >> >> The world is not ready for this and the languages, Ada included, are not >> mature enough either. >> >> So, yes, one can write an C-esque OS in Ada, but who needs yet another >> horse cart? >> > Often overlooked is that any "C-esque" POSIX compliant OS turns the > computer into a VAX. C was written to be easily translated into VAX > machine code and POSIX signals are all the original interrupts on a VAX. > If you have a CISC computer running VMS, C is your language. > Actually, C was written for the PDP-6, long before the VAX. It was used at AT&T to write UNIX for that machine, long before VMS.