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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,4215feeab2a8154a X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!postnews.google.com!z31g2000yqd.googlegroups.com!not-for-mail From: Maciej Sobczak Newsgroups: comp.lang.ada Subject: Re: C++0x and Threads - a poor relation to Ada's tasking model? Date: Tue, 11 Aug 2009 13:51:35 -0700 (PDT) Organization: http://groups.google.com Message-ID: <7961a91c-a5af-40e2-bbc0-6bf69a98176d@z31g2000yqd.googlegroups.com> References: <7q2385104kihs87d79p8kfphuoki6r01vq@4ax.com> NNTP-Posting-Host: 83.78.22.24 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1250023895 18997 127.0.0.1 (11 Aug 2009 20:51:35 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Tue, 11 Aug 2009 20:51:35 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: z31g2000yqd.googlegroups.com; posting-host=83.78.22.24; posting-account=bMuEOQoAAACUUr_ghL3RBIi5neBZ5w_S User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.13) Gecko/2009073021 Firefox/3.0.13,gzip(gfe),gzip(gfe) Xref: g2news2.google.com comp.lang.ada:7682 Date: 2009-08-11T13:51:35-07:00 List-Id: On 11 Sie, 17:30, John McCabe wrote: > I was just wondering if anyone here has been following the C++0x > development, particularly wrt concurrency etc. Yes. > Obviously we all know that one of the big issues Ada compilers had in > the early days was providing a supporting run-time system that was > robust, efficient and reliable. Right, we will come back to this statement. > To be honest, I haven't been following the C++0x development but, > based on what I have read about C++0x's threads stuff (based on > Boost.Thread) am I right in assuming that all that's being proposed is > a standardised abstraction of the threading functions of whatever OS > that your C++ program is running on? Yes. This basically standardizes the existing practice (which is very good for users) and allows easier implementation (which is very good for users). > I'm fairly sure this is how many Ada implementations work anyway, but > I believe there are (or have been) many Ada implementations developed > for bare machines where the Ada vendor provided the run time system. And there is absolutely nothing that could prevent the C++ vendor from implementing a stand-alone run-time that will implement the given API. > So, are we seeing something arriving in C++ that need only be > supported by implementations running on a 3rd party OS Absolutely not, see above. There is nothing that prevents vendors from implementing stand-alone run-times. Actually, with the API that is borrowed from *existing implementations* (read: maturity, industrial experience, etc.), implementing such a stand-alone run-time is actually much easier than being forced to work with API that is constructed in isolation from the existing practise. You might even pick a source code from the Linux kernel and build on that. Why not? This is the comfort that Ada vendors did not have. > or will threads need to be supported for bare machines > as well? No standard can force anybody to provide implementations. Vendors will do it if they will see a business opportunity in it. > Thanks for any responses. You are welcome. > This may seem like a C++ question, but it's > more a question of "why will Ada's threading model remain vastly > superior"! Why do you think it is "vastly superior"? It is certainly more complex, but the most visible effect of complexity is the cost (both in time and money) of implementation and this is where we come back to what you have stated at the beginning - the complexity of run-time has *hurt* Ada heavily at the beginning and the consequences of it are still visible in low adoption of the language. Being complex does not guarantee higher expressiveness, either. -- Maciej Sobczak * www.msobczak.com * www.inspirel.com Database Access Library for Ada: www.inspirel.com/soci-ada