* Re: Real time Java? Huh? [not found] ` <364224FB.7FCF@world.std.com> @ 1998-11-05 0:00 ` Pat Rogers 1998-11-06 0:00 ` Jay O'Connor 0 siblings, 1 reply; 22+ messages in thread From: Pat Rogers @ 1998-11-05 0:00 UTC (permalink / raw) David Chase wrote in message <364224FB.7FCF@world.std.com>... <snip> >Most of that commercial software is written in "unsafe" languages. >C++ is not safe. Pascal is not safe. Ada, as typically used, >is not safe. Detailed, hard evidence, please, regarding Ada. ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-05 0:00 ` Real time Java? Huh? Pat Rogers @ 1998-11-06 0:00 ` Jay O'Connor 1998-11-05 0:00 ` Joseph 0 siblings, 1 reply; 22+ messages in thread From: Jay O'Connor @ 1998-11-06 0:00 UTC (permalink / raw) On Thu, 5 Nov 1998 21:21:27 -0600, "Pat Rogers" <progers@NOclasswideSPAM.com> wrote: >David Chase wrote in message <364224FB.7FCF@world.std.com>... > ><snip> > >>Most of that commercial software is written in "unsafe" languages. >>C++ is not safe. Pascal is not safe. Ada, as typically used, >>is not safe. > >Detailed, hard evidence, please, regarding Ada. That one kinda surprised me as well because Ada was designed to be safe but also designed to support low level hardware access if needed. I mean, the language was originally targetted for embedded weapons systems and such, BTW - The onboard systems on the Boeing 777 are written in Ada. As are most of the train systems in Europe. Jay O'Connor joconnor@roadrunner.com http://www.roadrunner.com/~joconnor "God himself plays on the bass strings first, when he tunes the soul" ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` Jay O'Connor @ 1998-11-05 0:00 ` Joseph 1998-11-06 0:00 ` dewar ` (2 more replies) 0 siblings, 3 replies; 22+ messages in thread From: Joseph @ 1998-11-05 0:00 UTC (permalink / raw) I missed way too much of this thread. Java as a real time language? Tell me that this is a hoax, please. Joseph Jay O'Connor wrote: > On Thu, 5 Nov 1998 21:21:27 -0600, "Pat Rogers" > <progers@NOclasswideSPAM.com> wrote: > > >David Chase wrote in message <364224FB.7FCF@world.std.com>... > > > ><snip> > > > >>Most of that commercial software is written in "unsafe" languages. > >>C++ is not safe. Pascal is not safe. Ada, as typically used, > >>is not safe. > > > >Detailed, hard evidence, please, regarding Ada. > > That one kinda surprised me as well because Ada was designed to be > safe but also designed to support low level hardware access if needed. > > I mean, the language was originally targetted for embedded weapons > systems and such, > > BTW - The onboard systems on the Boeing 777 are written in Ada. As > are most of the train systems in Europe. > > Jay O'Connor > joconnor@roadrunner.com > http://www.roadrunner.com/~joconnor > > "God himself plays on the bass strings first, when he tunes the soul" ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-05 0:00 ` Joseph @ 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Jay O'Connor 1998-11-06 0:00 ` Jean-Pierre Rosen 2 siblings, 0 replies; 22+ messages in thread From: dewar @ 1998-11-06 0:00 UTC (permalink / raw) In article <36428b55.0@blushng.jps.net>, Joseph <**********@*******.**> wrote: > I missed way too much of this thread. > Java as a real time language? > Tell me that this is a hoax, please. Sorry, no one will tell you that, because it is most certainly the case that there are JVM systems that are suitable for real-time use. For an interesting demo, please stop by the Ada Core Technologies booth at the Washington Sig-Ada meeting next week, where you will see some real-time Java in action (well actually most of what you see will be Ada targetted to the JVM for real time use :-) Robert Dewar Ada Core Technologies -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-05 0:00 ` Joseph 1998-11-06 0:00 ` dewar @ 1998-11-06 0:00 ` Jay O'Connor 1998-11-06 0:00 ` oopster 1998-11-06 0:00 ` Jean-Pierre Rosen 2 siblings, 1 reply; 22+ messages in thread From: Jay O'Connor @ 1998-11-06 0:00 UTC (permalink / raw) On Thu, 05 Nov 1998 21:36:10 -0800, Joseph <**********@*******.**> wrote: >I missed way too much of this thread. Java as a real time language? >Tell me that this is a hoax, please. That gist of it is that some companies are breaking with Sun and trying to establish a standard for Java in real time systems. I remember being at a Alsys demonstration once where one of the Ada compiler writers warned against using exception handling in hard real time systems because you couldn't guarantee how long it would take to unwind to find the handler for the raised exception. I wonder if such conditions esist for exception handling in Java? (Or dynamic dispatch, for that matter) >Joseph > >Jay O'Connor wrote: > >> On Thu, 5 Nov 1998 21:21:27 -0600, "Pat Rogers" >> <progers@NOclasswideSPAM.com> wrote: >> >> >David Chase wrote in message <364224FB.7FCF@world.std.com>... >> > >> ><snip> >> > >> >>Most of that commercial software is written in "unsafe" languages. >> >>C++ is not safe. Pascal is not safe. Ada, as typically used, >> >>is not safe. >> > >> >Detailed, hard evidence, please, regarding Ada. >> >> That one kinda surprised me as well because Ada was designed to be >> safe but also designed to support low level hardware access if needed. >> >> I mean, the language was originally targetted for embedded weapons >> systems and such, >> >> BTW - The onboard systems on the Boeing 777 are written in Ada. As >> are most of the train systems in Europe. >> >> Jay O'Connor >> joconnor@roadrunner.com >> http://www.roadrunner.com/~joconnor >> >> "God himself plays on the bass strings first, when he tunes the soul" > Jay O'Connor joconnor@roadrunner.com http://www.roadrunner.com/~joconnor "God himself plays on the bass strings first, when he tunes the soul" ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` Jay O'Connor @ 1998-11-06 0:00 ` oopster 1998-11-06 0:00 ` Jay O'Connor ` (2 more replies) 0 siblings, 3 replies; 22+ messages in thread From: oopster @ 1998-11-06 0:00 UTC (permalink / raw) In article <3642a327.38883600@news.nmia.com>, joconnor@roadrunner.com wrote: > On Thu, 05 Nov 1998 21:36:10 -0800, Joseph <**********@*******.**> > wrote: > > >I missed way too much of this thread. Java as a real time language? > >Tell me that this is a hoax, please. > > That gist of it is that some companies are breaking with Sun and > trying to establish a standard for Java in real time systems. More accurately, the gist is that Sun has a proposed standard for real-time Java, and a group of other companies has also formed a consortium to promote a somewhat different realtime Java standard. The main issue seems to be the licensing terms for Sun Embedded Java. HP has already produced a competing embedded Java VM, which they are also licensing to other companies. > I remember being at a Alsys demonstration once where one of the Ada > compiler writers warned against using exception handling in hard real > time systems because you couldn't guarantee how long it would take to > unwind to find the handler for the raised exception. I wonder if such > conditions esist for exception handling in Java? (Or dynamic > dispatch, for that matter) Is it still the case that Ada exceptions are to be avoided for real-time? Not a good thing if true... It seems clear that deterministic exception handling will be critical to real-time Java efforts. I'm sure you can find out more about this at the various real-time Java websites if you're interested. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` oopster @ 1998-11-06 0:00 ` Jay O'Connor 1998-11-07 0:00 ` whiter5195 1998-11-07 0:00 ` Charles R. Lyttle 1998-11-09 0:00 ` JP Thornley 2 siblings, 1 reply; 22+ messages in thread From: Jay O'Connor @ 1998-11-06 0:00 UTC (permalink / raw) On Fri, 06 Nov 1998 19:11:46 GMT, oopster@my-dejanews.com wrote: >Is it still the case that Ada exceptions are to be avoided for real-time? >Not a good thing if true... Not sure. That was for Ada '83 about 5 or 6 years ago. Jay O'Connor joconnor@roadrunner.com http://www.roadrunner.com/~joconnor "God himself plays on the bass strings first, when he tunes the soul" ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` Jay O'Connor @ 1998-11-07 0:00 ` whiter5195 0 siblings, 0 replies; 22+ messages in thread From: whiter5195 @ 1998-11-07 0:00 UTC (permalink / raw) In article <36435a47.1894177@news.nmia.com>, joconnor@roadrunner.com wrote: > On Fri, 06 Nov 1998 19:11:46 GMT, oopster@my-dejanews.com wrote: > > >Is it still the case that Ada exceptions are to be avoided for real-time? > >Not a good thing if true... > > Not sure. That was for Ada '83 about 5 or 6 years ago. I know that we use as a code inspection checklist item that exceptions are not to be used for normal control flow. We do HRT. At "outside world" input interfaces, values are checked with normal logic comparisons and a completely deterministic response is given (often very helpful since the offending parameter is found in a very localized fashion). Could this be done in a more blanket fashion by enabling full Ada checks and having a local exception handler? Perhaps, but IMHO a system that is running properly _should_ not have any exceptions being raised. _____________________________________________________________________ Robert S. White -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` oopster 1998-11-06 0:00 ` Jay O'Connor @ 1998-11-07 0:00 ` Charles R. Lyttle 1998-11-09 0:00 ` JP Thornley 2 siblings, 0 replies; 22+ messages in thread From: Charles R. Lyttle @ 1998-11-07 0:00 UTC (permalink / raw) oopster@my-dejanews.com wrote: > > In article <3642a327.38883600@news.nmia.com>, > joconnor@roadrunner.com wrote: > > On Thu, 05 Nov 1998 21:36:10 -0800, Joseph <**********@*******.**> > > wrote: > > > > >I missed way too much of this thread. Java as a real time language? > > >Tell me that this is a hoax, please. > > > > That gist of it is that some companies are breaking with Sun and > > trying to establish a standard for Java in real time systems. > > More accurately, the gist is that Sun has a proposed standard for real-time > Java, and a group of other companies has also formed a consortium to promote > a somewhat different realtime Java standard. The main issue seems to be the > licensing terms for Sun Embedded Java. > > HP has already produced a competing embedded Java VM, which they are also > licensing to other companies. > > > I remember being at a Alsys demonstration once where one of the Ada > > compiler writers warned against using exception handling in hard real > > time systems because you couldn't guarantee how long it would take to > > unwind to find the handler for the raised exception. I wonder if such > > conditions esist for exception handling in Java? (Or dynamic > > dispatch, for that matter) > > Is it still the case that Ada exceptions are to be avoided for real-time? > Not a good thing if true... > > It seems clear that deterministic exception handling will be critical to > real-time Java efforts. I'm sure you can find out more about this at the > various real-time Java websites if you're interested. > > -----------== Posted via Deja News, The Discussion Network ==---------- > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own Exceptions are never to be used in Ada ( or Java) for any reason other than to catch totaly unpredictable disasters. Java IOStreams will have to be completely re-written if Java is to be used in hard real-time systems. Until then don't use ^D or ^Z to end an input stream. -- Russ Lyttle, PE <http://www.flash.net/~lyttlec> ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` oopster 1998-11-06 0:00 ` Jay O'Connor 1998-11-07 0:00 ` Charles R. Lyttle @ 1998-11-09 0:00 ` JP Thornley 2 siblings, 0 replies; 22+ messages in thread From: JP Thornley @ 1998-11-09 0:00 UTC (permalink / raw) In article: <71vhli$hul$1@nnrp1.dejanews.com> oopster@my-dejanews.com writes: > > Is it still the case that Ada exceptions are to be avoided for real-time? > Not a good thing if true... > For high-integrity Ada, I've always been fascinated by the existence of the two opposed camps on exceptions - one group taking the view that having exceptions in the language makes it *more* suitable for high-integrity applications and the other regarding them as, not quite the work of the devil, but definitely not something that self-respecting software engineers would want to get involved with. The Annex H Rapporteur Group spent a long time discussing the appropriate advice to give for exceptions in the (currently Draft) "Guide for the Use of the Ada Programming Language in High Integrity Systems" with the result that it describes three different approaches:- 1. Catch and handle all exceptions locally - so there is no exception propagation; program state must be well-defined after the handler has executed. 2. Use a single catch-all handler at the top level that makes almost no assumptions about program state - it probably does a restart. 3. Prove that no run-time errors can occur (so code can be compiled with all checks suppressed). [But you often still include the 'catch-all' handler to cope with hardware glitches/memory corruptions.] Phil Thornley -- ------------------------------------------------------------------------ | JP Thornley EMail jpt@diphi.demon.co.uk | | phil.thornley@acm.org | ------------------------------------------------------------------------ ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-05 0:00 ` Joseph 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Jay O'Connor @ 1998-11-06 0:00 ` Jean-Pierre Rosen 1998-11-06 0:00 ` dewar 2 siblings, 1 reply; 22+ messages in thread From: Jean-Pierre Rosen @ 1998-11-06 0:00 UTC (permalink / raw) Joseph <**********@*******.**> a �crit dans le message <36428b55.0@blushng.jps.net>... >I missed way too much of this thread. Java as a real time language? >Tell me that this is a hoax, please. > At an AFNOR-Ada (French standardization body) we had a discussion about this yesterday. It seems that by real-time Java, people really mean "embedded Java", i.e. in SmartCards for example. When I asked how extensive dynamic allocation and garbage collector could be used in smart-cards, people told me that there were restrictions, like only final classes with only final methods... When I asked why use Java rather than C, and why not call such "classes" packages, I had no answer... sigh. ---------------------------------------------------------------------------- J-P. Rosen (Rosen.Adalog@wanadoo.fr) Visit Adalog's web site at http://perso.wanadoo.fr/adalog ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` Jean-Pierre Rosen @ 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Roga Danar ` (2 more replies) 0 siblings, 3 replies; 22+ messages in thread From: dewar @ 1998-11-06 0:00 UTC (permalink / raw) [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain, Size: 1279 bytes --] In article <71uc8n$lu1$1@platane.wanadoo.fr>, "Jean-Pierre Rosen" <rosen.adalog@wanadoo.fr> wrote: > > Joseph <**********@*******.**> a �crit dans le message > <36428b55.0@blushng.jps.net>... > >I missed way too much of this thread. Java as a real time language? > >Tell me that this is a hoax, please. > > > At an AFNOR-Ada (French standardization body) we had a discussion > about this yesterday. > It seems that by real-time Java, people really mean "embedded Java", > i.e. in SmartCards for example. When I asked how extensive dynamic > allocation and garbage collector could be used in smart-cards, > people told me that there were restrictions, like only final classes > with only final methods... When I asked why use Java rather than > C, and why not call such "classes" packages, I had no answer... > sigh. There are very good reasons for using JVM based approaches for real time embedded systems, and you should not just assume that garbage collection is out of the question in such systems. This is why it is so important that we have Ada 95 systems that target the JVM! Robert Dewar Ada Core Technologies -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` dewar @ 1998-11-06 0:00 ` Roga Danar 1998-11-06 0:00 ` Jean-Pierre Rosen 1998-11-06 0:00 ` Roga Danar 2 siblings, 0 replies; 22+ messages in thread From: Roga Danar @ 1998-11-06 0:00 UTC (permalink / raw) Timing is a better (or another) reason why one should look twice at a Java for a real-time system must instead of Ada. Real-Time embedded systems that frequently require persice processing in a narrow time margin would be better off with Ada, IHO. dewar@gnat.com wrote: > In article <71uc8n$lu1$1@platane.wanadoo.fr>, > "Jean-Pierre Rosen" <rosen.adalog@wanadoo.fr> wrote: > > > > Joseph <**********@*******.**> a �crit dans le message > > <36428b55.0@blushng.jps.net>... > > >I missed way too much of this thread. Java as a real > time language? > > >Tell me that this is a hoax, please. > > > > > At an AFNOR-Ada (French standardization body) we had a > discussion > > about this yesterday. > > It seems that by real-time Java, people really mean > "embedded Java", > > i.e. in SmartCards for example. When I asked how > extensive dynamic > > allocation and garbage collector could be used in > smart-cards, > > people told me that there were restrictions, like only > final classes > > with only final methods... When I asked why use Java > rather than > > C, and why not call such "classes" packages, I had no > answer... > > sigh. > > There are very good reasons for using JVM based approaches > for real time embedded systems, and you should not just > assume that garbage collection is out of the question in > such systems. This is why it is so important that we have > Ada 95 systems that target the JVM! > > Robert Dewar > Ada Core Technologies > > -----------== Posted via Deja News, The Discussion Network ==---------- > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Roga Danar @ 1998-11-06 0:00 ` Jean-Pierre Rosen 1998-11-07 0:00 ` dewarr 1998-11-06 0:00 ` Roga Danar 2 siblings, 1 reply; 22+ messages in thread From: Jean-Pierre Rosen @ 1998-11-06 0:00 UTC (permalink / raw) dewar@gnat.com a �crit dans le message <71usgj$uv4$1@nnrp1.dejanews.com>... >There are very good reasons for using JVM based approaches >for real time embedded systems, and you should not just >assume that garbage collection is out of the question in >such systems. This is why it is so important that we have >Ada 95 systems that target the JVM! > Sure. Garbage collection is not out of the question for some systems, but there are certainly many RT systems where it is an issue. Anyway, the issue was not about the JVM, but about the Java language. I keep trying to separate these issues clearly - Guess why! BTW, can we deduce from your message that the soon-to-be-delivered GNAT 3.11p will include GNAT-for-Java ? ---------------------------------------------------------------------------- J-P. Rosen (Rosen.Adalog@wanadoo.fr) Visit Adalog's web site at http://perso.wanadoo.fr/adalog ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` Jean-Pierre Rosen @ 1998-11-07 0:00 ` dewarr 1998-11-07 0:00 ` bill 1998-11-10 0:00 ` Richard IRVINE 0 siblings, 2 replies; 22+ messages in thread From: dewarr @ 1998-11-07 0:00 UTC (permalink / raw) In article <71ve5m$iv2$1@platane.wanadoo.fr>, "Jean-Pierre Rosen" <rosen.adalog@wanadoo.fr> wrote: BTW, can we deduce from your message that the > soon-to-be-delivered GNAT 3.11p will include > GNAT-for-Java ? No, not yet, GNAT-for-Java is still very much in the testing phase, but it is getting closer, we have some customers doing serious evaluations, and as I mentioned you will be able to see an interesting real-time demo at SigAda. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-07 0:00 ` dewarr @ 1998-11-07 0:00 ` bill 1998-11-10 0:00 ` Richard IRVINE 1 sibling, 0 replies; 22+ messages in thread From: bill @ 1998-11-07 0:00 UTC (permalink / raw) In article <720mvr$gg4$1@nnrp1.dejanews.com>, dewarr@my-dejanews.com says... > > >No, not yet, GNAT-for-Java is still very much in the >testing phase, but it is getting closer, we have some >customers doing serious evaluations, and as I mentioned you >will be able to see an interesting real-time demo at >SigAda. > Cool stuff ! go Ada ! Bill. ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-07 0:00 ` dewarr 1998-11-07 0:00 ` bill @ 1998-11-10 0:00 ` Richard IRVINE 1998-11-10 0:00 ` dennison ` (2 more replies) 1 sibling, 3 replies; 22+ messages in thread From: Richard IRVINE @ 1998-11-10 0:00 UTC (permalink / raw) I see so many raging discussions on this newsgroup (comp.lang.java.advocacy) about templates or named parameters that it is refreshing to see contributions from the somewhat calmer Ada world, where many of these problems were well thought out years if not decades ago. GNAT for Java sounds interesting. I wonder whether GNAT for Java implies coding in a subset of Ada, without pointers or access types and without manual memory allocation/deallocation, or will we be free to carry across dangling pointer and memory leakage problems from Ada into Java? dewarr@my-dejanews.com wrote: > In article <71ve5m$iv2$1@platane.wanadoo.fr>, > "Jean-Pierre Rosen" <rosen.adalog@wanadoo.fr> wrote: > > BTW, can we deduce from your message that the > > soon-to-be-delivered GNAT 3.11p will include > > GNAT-for-Java ? > > No, not yet, GNAT-for-Java is still very much in the > testing phase, but it is getting closer, we have some > customers doing serious evaluations, and as I mentioned you > will be able to see an interesting real-time demo at > SigAda. > > -----------== Posted via Deja News, The Discussion Network ==---------- > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-10 0:00 ` Richard IRVINE @ 1998-11-10 0:00 ` dennison 1998-11-10 0:00 ` Stephen Leake 1998-11-12 0:00 ` dewarr 2 siblings, 0 replies; 22+ messages in thread From: dennison @ 1998-11-10 0:00 UTC (permalink / raw) In article <364874D1.D788CE9C@eurocontrol.fr>, Richard IRVINE <richard.irvine@eurocontrol.fr> wrote: > > GNAT for Java sounds interesting. I wonder whether GNAT for Java implies > coding in a subset of Ada, without pointers or access types and without > manual memory allocation/deallocation, or will we be free to carry across > dangling pointer and memory leakage problems from Ada into Java? Actually, I don't believe it is possible to have dangling pointers in Ada w/o using one of the "unchecked" programming constructs. From what I know of Java, I suspect the Java Virtual Machine wouldn't support Ada unchecked programming constructs anyway. -- T.E.D. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-10 0:00 ` Richard IRVINE 1998-11-10 0:00 ` dennison @ 1998-11-10 0:00 ` Stephen Leake 1998-11-12 0:00 ` dewarr 2 siblings, 0 replies; 22+ messages in thread From: Stephen Leake @ 1998-11-10 0:00 UTC (permalink / raw) Richard IRVINE <richard.irvine@eurocontrol.fr> writes: > I see so many raging discussions on this newsgroup > (comp.lang.java.advocacy) about templates or named parameters that it is > refreshing to see contributions from the somewhat calmer Ada world, where > many of these problems were well thought out years if not decades ago. > > GNAT for Java sounds interesting. I wonder whether GNAT for Java implies > coding in a subset of Ada, without pointers or access types and without > manual memory allocation/deallocation, or will we be free to carry across > dangling pointer and memory leakage problems from Ada into Java? It's not "GNAT-for-Java", but rather "GNAT-for-JVM" (Java Virtual Machine). Since the JVM allows pointers and access types, GNAT-for-JVM will too (or at least I hope so - I don't have it yet !). ObjectAda-for-JVM allows pointers and access types now; it supports all of Ada (barring the many bugs, and most of the annexes :). -- Stephe ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-10 0:00 ` Richard IRVINE 1998-11-10 0:00 ` dennison 1998-11-10 0:00 ` Stephen Leake @ 1998-11-12 0:00 ` dewarr 1998-11-12 0:00 ` Jon S Anthony 2 siblings, 1 reply; 22+ messages in thread From: dewarr @ 1998-11-12 0:00 UTC (permalink / raw) In article <364874D1.D788CE9C@eurocontrol.fr>, Richard IRVINE <richard.irvine@eurocontrol.fr> wrote: > > I see so many raging discussions on this newsgroup > (comp.lang.java.advocacy) about templates or named parameters that it is > refreshing to see contributions from the somewhat calmer Ada world, where > many of these problems were well thought out years if not decades ago. > > GNAT for Java sounds interesting. I wonder whether GNAT for Java implies > coding in a subset of Ada, without pointers or access types and without > manual memory allocation/deallocation, or will we be free to carry across > dangling pointer and memory leakage problems from Ada into Java? GNAT-for-Java will support the entire Ada language, with the exception of certain representation clauses that do not make sense in the JVM environment. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-12 0:00 ` dewarr @ 1998-11-12 0:00 ` Jon S Anthony 0 siblings, 0 replies; 22+ messages in thread From: Jon S Anthony @ 1998-11-12 0:00 UTC (permalink / raw) > GNAT-for-Java will support the entire Ada language, with the > exception of certain representation clauses that do not make sense > in the JVM environment. This doesn't mean you are not going to use the GC in the JVM, right? You will support completely GC style programming, right? Admittedly the current JVM GC is a complete piece of trash, but the claim is that final 1.2 will have a "decent" generational scavenging collector. /Jon -- Jon Anthony Synquiry Technologies, Ltd. Belmont, MA 02478, 617.484.3383 "Nightmares - Ha! The way my life's been going lately, Who'd notice?" -- Londo Mollari ^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: Real time Java? Huh? 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Roga Danar 1998-11-06 0:00 ` Jean-Pierre Rosen @ 1998-11-06 0:00 ` Roga Danar 2 siblings, 0 replies; 22+ messages in thread From: Roga Danar @ 1998-11-06 0:00 UTC (permalink / raw) dewar@gnat.com wrote: > In article <71uc8n$lu1$1@platane.wanadoo.fr>, > "Jean-Pierre Rosen" <rosen.adalog@wanadoo.fr> wrote: > > > > Joseph <**********@*******.**> a �crit dans le message > > <36428b55.0@blushng.jps.net>... > > >I missed way too much of this thread. Java as a real > time language? > > >Tell me that this is a hoax, please. > > > > > At an AFNOR-Ada (French standardization body) we had a > discussion > > about this yesterday. > > It seems that by real-time Java, people really mean > "embedded Java", > > i.e. in SmartCards for example. When I asked how > extensive dynamic > > allocation and garbage collector could be used in > smart-cards, > > people told me that there were restrictions, like only > final classes > > with only final methods... When I asked why use Java > rather than > > C, and why not call such "classes" packages, I had no > answer... > > sigh. > > There are very good reasons for using JVM based approaches > for real time embedded systems, and you should not just > assume that garbage collection is out of the question in > such systems. This is why it is so important that we have > Ada 95 systems that target the JVM! > > Robert Dewar > Ada Core Technologies > > -----------== Posted via Deja News, The Discussion Network ==---------- > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own > Timing is a better (or another) reason why one should look twice at a Java for a real-time system must instead of Ada. Real-Time embedded systems that frequently require persice processing in a narrow time margin would be better off with Ada, IHO. ^ permalink raw reply [flat|nested] 22+ messages in thread
end of thread, other threads:[~1998-11-12 0:00 UTC | newest] Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <363E1DE8.4189EBAC@solaris.ok> [not found] ` <nagleF1uyME.3IA@netcom.com> [not found] ` <364024f5.3575731@news.demon.co.uk> [not found] ` <364071C4.619D@world.std.com> [not found] ` <3641ca4b.23637018@news.demon.co.uk> [not found] ` <3641B718.DBF4C37C@tisny.com> [not found] ` <36431ca0.301400410@news.netcomuk.co.uk> [not found] ` <364224FB.7FCF@world.std.com> 1998-11-05 0:00 ` Real time Java? Huh? Pat Rogers 1998-11-06 0:00 ` Jay O'Connor 1998-11-05 0:00 ` Joseph 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Jay O'Connor 1998-11-06 0:00 ` oopster 1998-11-06 0:00 ` Jay O'Connor 1998-11-07 0:00 ` whiter5195 1998-11-07 0:00 ` Charles R. Lyttle 1998-11-09 0:00 ` JP Thornley 1998-11-06 0:00 ` Jean-Pierre Rosen 1998-11-06 0:00 ` dewar 1998-11-06 0:00 ` Roga Danar 1998-11-06 0:00 ` Jean-Pierre Rosen 1998-11-07 0:00 ` dewarr 1998-11-07 0:00 ` bill 1998-11-10 0:00 ` Richard IRVINE 1998-11-10 0:00 ` dennison 1998-11-10 0:00 ` Stephen Leake 1998-11-12 0:00 ` dewarr 1998-11-12 0:00 ` Jon S Anthony 1998-11-06 0:00 ` Roga Danar
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