February 2009 - Pharo-dev - lists.pharo.org

[Pharo-project] newDelta >0 failed in sqUnixMemory -- Was Re: Incompatibility between Pharo and Seasidehosting

by Bruce O'Neel

Hi, Um, yes, I know you've discussed this before, but.... I'm not sure it's just a gcc 4.3.2 problem. I downloaded and poked at the tar file of 3.10-4's source. I got this from http://squeakvm.org/unix/. The error message comes from uxGrowMemoryBy, but, I think it comes from being called (two frames higher) in incrementalGC. The code is (from the gnu-interp.c file, though interp.c is the same): if (((((usqInt) ((longAt(foo->freeBlock)) & AllButTypeMask))) < (((usqInt) foo->growHeadroom))) && (foo->gcBiasToGrow > 0)) { /* begin biasToGrow */ /* begin growObjectMemory: */ foo->statGrowMemory += 1; limit = sqGrowMemoryBy(foo->memoryLimit, growSize); if (!(limit == foo->memoryLimit)) { foo->memoryLimit = limit - 24; initializeMemoryFirstFree(foo->freeBlock); } weDidGrow = 1; } So we call sqGrowMemoryBy with growSize which is used to calculate newDelta in uxGrowMemoryBy. A search of incrementalGC though shows that growSize, a sqInt is declared it's never set. It turns out that with my system (Debian Lenny ppc, with gcc 4.3.2) growSize is zeroed. Maybe that's the 'problem' with gcc 4.3.2? If I set it to some number, say, 100000, then a print statement just before sqGrowMemoryBy comes out and squeak grows its memory, and, volia, no crash. Now, this might just be bypassing the real problem, but, it's unclear to me how an uninitialized growSize would be a good idea. This also explains why my previous workaround, using the flag -memory on the command line, caused the problem to not occur. cheers bruce On Thu, Feb 19, 2009 at 09:18:49AM -0800, John M McIntosh wrote: > look in the archive and on the vm-dev list I think people agree this > is a gcc 4.3 issue. > > On 19-Feb-09, at 4:15 AM, Bruce O'Neel wrote: > > > Hi, > > > > Is it possible this error? > > > > sqUnixMemory.c:172: uxGrowMemoryBy: Assertion `newDelta >= 0` failed. > > Aborted > > > > I get this following the procedure below on a Debian Lenny PPC > > system with Squeak 3.10-4. > > Gcc is 4.3.2. I do not get this on a Ubuntu hardy ppc system with > > the same version of squeak. > > Gcc is slightly older at 4.2.3. > > > > I've worked around this, for the moment, by adding -memory 200m to > > the squeak > > command line. > > > > I spent some weekend debugging this, but, I didn't find where the > > problem it is comes > > from. > > > > cheers > > > > bruce > > -- > = > = > = > ======================================================================== > John M. McIntosh <johnmci(a)smalltalkconsulting.com> > Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com > = > = > = > ======================================================================== > > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

Feb. 20, 2009

[Pharo-project] Debugger problem with Windows Vista

by Marco D'Ambros

Hi, in a course about web development we are using pharo and seaside. One of the student has windows vista and for this student the debugger does not work, in the sense that it does not even appear. It only appears the dialog which asks "proceed, abort, debug", but when pressing debug the same dialog appear. He's using the last squeak vm for windows and the last development image from the pharo web page. The same image on the mac does not have this problem. Any idea? Thanks and cheers Marco

Feb. 20, 2009

[Pharo-project] Automatic focus on column upon moose enter

by Alexandre Bergel

David, You're a hero! Thanks for OB-Enhancements-dr.305 Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

Feb. 20, 2009

Re: [Pharo-project] Question about Universes

by StÃ©phane Ducasse

On Feb 20, 2009, at 8:44 AM, Keith Hodges wrote: > StÃ©phane Ducasse wrote: >> But we do not want hacks. :) and hidden dependencies. >> Frankly I do not understand why this is not possible to use a method >> (since a method is a script with a name). >> > Because methods have to compile, or they are not accepted. > > In bob's case these are scripts that will run in a different image, so > do not necessarily compile in Bob's image. > > In mantis's case these are the bug reports downloaded for searching > and > reference purposes. > > I dont regard this as a hack since Smalltalk is designed to have this > flexibility of supporting differnnt languages, and syntaxes. If you > dont > like it then why not remove #compilerClass altogether. > > If you call this a hack then what is WAFileDirectory? You would think > that using methods to store data in the image has never been done > before. but these images do not require to extend the compiler. What I do not understand is how the browse also shows you this extra code at the end of methods. My gut feeling is that there is certainly a clean way to do that. > > > Keith > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >

Feb. 20, 2009

Re: [Pharo-project] Question about Universes

by Lukas Renggli

> Where is the documentation? http://www.refactory.com/RefactoringBrowser/BrowserPagesLint.html For an overview of RB: http://www.refactory.com/RefactoringBrowser/index.html Lukas -- Lukas Renggli http://www.lukas-renggli.ch

Feb. 20, 2009

Re: [Pharo-project] Incompatibility between Pharo and Seasidehosting

by Bruce O'Neel

Hi, Thanks. I kind of assumed this, but, sigh, running gdb is fun, right? cheers bruce On Thu, Feb 19, 2009 at 09:18:49AM -0800, John M McIntosh wrote: > look in the archive and on the vm-dev list I think people agree this > is a gcc 4.3 issue. > > On 19-Feb-09, at 4:15 AM, Bruce O'Neel wrote: > > > Hi, > > > > Is it possible this error? > > > > sqUnixMemory.c:172: uxGrowMemoryBy: Assertion `newDelta >= 0` failed. > > Aborted > > > > I get this following the procedure below on a Debian Lenny PPC > > system with Squeak 3.10-4. > > Gcc is 4.3.2. I do not get this on a Ubuntu hardy ppc system with > > the same version of squeak. > > Gcc is slightly older at 4.2.3. > > > > I've worked around this, for the moment, by adding -memory 200m to > > the squeak > > command line. > > > > I spent some weekend debugging this, but, I didn't find where the > > problem it is comes > > from. > > > > cheers > > > > bruce > > -- > = > = > = > ======================================================================== > John M. McIntosh <johnmci(a)smalltalkconsulting.com> > Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com > = > = > = > ======================================================================== > > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

Feb. 20, 2009

[Pharo-project] Postdoctoral position on language design

by StÃ©phane Ducasse

The INRIA RMoD Team led by S. Ducasse has an open position on traits. http://rmod.lille.inria.fr/ http://stephane.ducasse.free.fr/ End of the campaign : May 4, 2009 Beginning of the positions: from September to December 2009 CONTEXT INRIA, the national institute for research in computer science and control, is dedicated to fundamental and applied research in information and communication science and technology (ICST). The Institute has a workforce of 3,700, 2,900 of whom are scientists from INRIA and its partner organizations. INRIA has an annual budget of 162 million euros, 20% of which comes from its own research contracts and development products. INRIA develops many partnerships with industry and fosters technology transfer and company foundations in the field of ICST - some eighty companies have been funded. Startups are financed in particular by INRIA Transfert, a subsidiary of INRIA that supports four startup funds. The international collaborations are based on an incentive strategy of welcoming and recruiting foreign students as well as developing strong exchanges between research scientists. Priority is given to geographic zones with strong growth: Europe, Asia and North America while maintaining reasonable cooperation with South America, Africa and Middle-East. from http://www.inria.fr/lille/scientific-research/research-teams/RMOD_page : The goal of RMoD is to support remodularization of object-oriented applications. This objective is tackled from two complementary perspectives: reengineering and modularity constructs for programming languages. In the reengineering perspective we will propose new analyses to understand and restructure existing large applications (specialized package metrics, adapted visualizations, layer identifications). In the modularity construct context we will work on a pure trait-based language and new modular abstractions. We will also propose the definition of dedicated secure language constructs based on a modular and layered kernel as one direct application of modularization. These programming language constructs will be experimented on Pharo, a platform for dynamic web development. Pharo will be used as a testbed for a pure-traits language, which will be used to assess the impact of modular classes in terms of reuse orthogonally to inheritance. SCIENTIFIC CONTEXT Recently, traits have been proposed as a single inheritance backward compatible solution in which the composing entity has the control over the trait composition. Traits are fine-grained units used to compose classes, while avoiding many of inheritance and mixin-based approaches. To evaluate the expressiveness of traits, some hierarchies were refactored, showing code reuse. However, such large refactorings, while valuable, may not be facing all the problems, since the hierarchies were previously expressed within single inheritance and following certain patterns. In addition traits have always been considered in addition to class inheritance but not as the main composition and reuse mechanism. Goals We are in the process of designing a pure traits based language. We want to evaluate the impact of having only traits as building blocks and removing inheritance from an object-oriented language. We expect the candidate to take part of the design of a pure traits- based programming language, to perform analysis on large piece of software for remodularisation purposes and redesign a library. We expect the candidate to implement the core of a pure trait-based language and some representative examples. Expected Skills -have good skills in interpretation of object-oriented programming languages (classbased, prototypes, mixins...) - have an expertise in object-oriented programming languages outside Java, C++ and C# - be fluent in English Bilbiographical References: 1 Alexandre Bergel, StÃ©phane Ducasse, Oscar Nierstrasz and Roel Wuyts, Stateful Traits and their Formalization, Journal of Computer Languages, Systems and Structures, 2008. 2 Damien Cassou, Stphane Ducasse and Roel Wuyts, Redesigning with Traits: the Nile Stream trait-based Library, International Conference on Dynamic Languages 2007, 2007, pp. 50-79. 3 StÃ©phane Ducasse, Oscar Nierstrasz, Nathanael Schaerli, Roel Wuyts and Andrew Black, Traits: A Mechanism for fine-grained Reuse, ACM Transactions on Programming Languages and Systems (TOPLAS), vol. 28, no. 2, March 2006, pp. 331-388. 4 Luigi Liquori and Arnaud Spiwack, FeatherTrait: A Modest Extension of Featherweight Java, ACM Transactions on Programming Languages and Systems (TOPLAS), 2007, To appear. 5 Nathanael Schaerli, StÃ©phane Ducasse, Oscar Nierstrasz and Andrew Black, Traits: Composable Units of Behavior, Proceedings of European Conference on Object-Oriented Programming (ECOOP'03), LNCS, vol. 2743, Springer Verlag, July 2003, pp. 248-274. APPLICATION REQUIREMENTS Applicant should have held a doctorate or Ph.D. for less than one year or you are about to obtain one and you would like to carry out a fulfilling research activity in the field of ICST (information and communication science and technology) or in a related field. POSITION SALARY 2,357.30 EUR gross per month (Social security already payed) SOCIAL SECURITY BENEFITS - Entitled to unemployment benefit at the end of the contract; - Affiliated to the French social security system. HOW TO APPLY Thank you for applying directly on the institute's website, by following this link: = http://www.inria.fr/travailler/opportunites/postdoc/postdoc.en.html

Feb. 20, 2009

Re: [Pharo-project] Question about Universes

by Keith Hodges

StÃ©phane Ducasse wrote: > But we do not want hacks. :) and hidden dependencies. > Frankly I do not understand why this is not possible to use a method > (since a method is a script with a name). > Because methods have to compile, or they are not accepted. In bob's case these are scripts that will run in a different image, so do not necessarily compile in Bob's image. In mantis's case these are the bug reports downloaded for searching and reference purposes. I dont regard this as a hack since Smalltalk is designed to have this flexibility of supporting differnnt languages, and syntaxes. If you dont like it then why not remove #compilerClass altogether. If you call this a hack then what is WAFileDirectory? You would think that using methods to store data in the image has never been done before. Keith

Feb. 20, 2009

Re: [Pharo-project] Question about Universes

by StÃ©phane Ducasse

But we do not want hacks. :) and hidden dependencies. Frankly I do not understand why this is not possible to use a method (since a method is a script with a name). >>> >> > Well I never liked it, when I used it last I only had a 700Mhz machine > to work on, it was slow, buggy, menu items I used frequently were > missing. In short it was impossible to actually use. But it is working since years now. I never understood why some Squeakers did not the value of it. For Pharo I would like to have deeper integration of RB engine. Stef

Feb. 20, 2009

Re: [Pharo-project] Question about Universes

by Keith Hodges

Lukas Renggli wrote: >> It doesn't depend upon that compiler hack. That hack provides the >> ability to put textual data in as an appendix to a method. It is an >> entirely independent facility that could be perhaps better included as a >> trait for those that want it. >> > > The version I found in the latest Pharo-Dev images has the compiler > hack loaded and depends on it (or the package definitions). > The package definitions do not depend on it, it allows the compiler to ignore code after 6 quote marks. myMethod ^ self """""" Some text here as documentation. Bob will also use this facility, because it provides a place to put scripts verbatim without having to escape quotes. Again you dont have to use it. >> I don't think it is fair to use code critics as an argument. >> > > You can't deny that references to variables and classes that do not > exist in the system are not a serious bug. > Yes I can, because plainly it hasnt effected use for while. If the tests run then its not a serious bug. These sot of artifacts are unwanted side effects in a rapidly evolving code base, they are not a big deal in the grand scheme of things. >> To me it >> appears that you have developed all of these tools for your own use. >> > > Code Critics is part of the refactoring browser by Don Roberts and John Brant. > > The refactoring browser is one of the most amazing pieces of Smalltalk > code I have ever seen. I am maintaining the code-base in Pharo (and > Well I never liked it, when I used it last I only had a 700Mhz machine to work on, it was slow, buggy, menu items I used frequently were missing. In short it was impossible to actually use. > previously in Squeak), because it makes me much more productive in my > daily work. Code critics provides a huge set of high quality tests for > free that can quickly point out flaws in code. It is not always > correct, but it is usually very good to find the problematic parts of > a system ok Keith

Feb. 20, 2009