Squeak-dev February 2008

squeak-dev@lists.squeakfoundation.org

159 participants
219 discussions

3.10 image
by itsme213 15 Jul '08

15 Jul '08

I the damien-3.10-web image size is quite large (129M) compared to a comparably (not identical) loaded 3.9 Ramon's image (42M). Is that expected, or is it because as a beta it has not been trimmed etc.? Thanks - Sophie

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[ANN] ESUG 2008 Call for Contribution
by stephane ducasse 04 May '08

04 May '08

Hi all we are really happy to announce that ... --------------------------------------------------------------------- 16th International Smalltalk Joint Conference - Call for Contributions August 25-29, 2008 - Amsterdam, the Netherlands http://www.esug.org/conferences/2008/ ---------------------------------------------------------------------- For the past 16 years, the European Smalltalk User Group (ESUG) has organised the International Smalltalk Conference, a lively forum on cutting edge software technologies that attract people from both academia and industry for a whole week. The attendees are both engineers using Smalltalk in business and students and teachers using Smalltalk both for research and didactic purposes. As every year, this year's edition of the largest European Smalltalk event will include the regular Smalltalk developers conference with renowned invited speakers, a Smalltalk camp that proves fruitful for interactions and discussions. Besides, this year will be held the 4th edition of the Innovation Technology Awards where prizes will be awarded to authors of best pieces of Smalltalk-related projects. You can support the ESUG conference in many different ways: * Sponsor the conference. New sponsoring packages are described at http://www.esug.org/supportesug/becomeasponsor/ * Submit a talk, a software or a paper to one of the events. See below. * Attend the conference. We'd like to beat the previous record of attendance (116 people at Köthen, Germany in 2004)! * Students can get free registration and hosting if they enroll into the the Student Volunteers program. See below. The conference features the following events: * Camp Smalltalk - There will be a Smalltalk camp the 23-24th of august * Developers Forum * Technology Forum Developers Forum : International Smalltalk Developers Conference ------------------ This year we are looking for YOUR experience on using Smalltalk. The list of topics includes, but is not limited to the following: * XP practices * Development tools * Experience reports * Model driven development * Web development * Team management * Meta-Modeling * Security * New libraries & frameworks * Educational material * Embedded systems and robotics * SOA and Web services * Interaction with other programming languages Submissions due on 1st June 2008 Notification of acceptance on 15 of June 2008 More information at http://www.esug.org/conferences/2008 How to sumbit? ------------------ Pay attention: the places are limited so do not wait till the last minute to apply. Prospective presenters should submit a request to esug-info(a)esug.org following the template below. Please use this template since the email will be automatically processed! Subject: [ESUG 2008 Developers] + your name First Name: Last Name: Email where you can always be reached: Title: Abstract: Bio: Any presentation not respecting this form will be discarded automatically Technology Forum ------------------ We are proud to announce the 4th Innovation Technology Awards. The top 3 teams with the most innovative software will receive, respectively, 500 Euros, 300 Euros and 200 Euros during an awards ceremony at the conference. Developers of any Smalltalk-based software are welcome to compete. More information at http://www.esug.org/conferences/2008 Student Volunteer Program ------------------ If you are a student wanting to attend ESUG, have you considered being a student volunteer? Student volunteers help keep the conference running smoothly; in return, they have free accommodations, while still having most of the time to enjoy the conference. More information at http://www.esug.org/conferences/2008 http://www.esug.org/conferences/16thinternationalsmalltalkjointconference20… We hope to see you there and have fun together.

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OmniBase/Magma - how big??
by Bill Schwab 02 Apr '08

02 Apr '08

Hello all, Any success or horror stories with OmniBase and/or Magma? Can you report that either worked well at or got into trouble beyond any particular size (either in object count or bytes of data)? Other comments? Bill Wilhelm K. Schwab, Ph.D. University of Florida Department of Anesthesiology PO Box 100254 Gainesville, FL 32610-0254 Email: bschwab(a)anest.ufl.edu Tel: (352) 846-1285 FAX: (352) 392-7029

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The "correct" approach to multi-core systems.
by Michael van der Gulik 22 Mar '08

22 Mar '08

On 2/22/08, Stephen Pair <stephen(a)pairhome.net> wrote: > > I must say, this is a really impressive development. I really think this > is the right way to approach multi-core systems. > I disagree about it being the right approach in the long term. In the short term, the Hydra VM allows the use of multiple cores without large changes to the core of Squeak, which is good and IMHO the right decision for a quick and reliable solution (for whoever Igor is doing his work for... Qwaq?). The disadvantage with the Hydra VM is that all inter-process communication needs to go through a pipe; this makes sharing objects and synchronising access while still getting good performance more difficult. I can't back up my claims yet; we'll see how Hydra VM works out. In the long term, a VM that can run its green threads (aka Process) on multiple OS threads (aka pthreads) should be the long-term goal. I can't imagine that hacking the VM with multiple processes, per-process state and a global VM lock for garbage collection and new object creation would be too difficult. The global VM lock would kill scalability and could make object creation slow, but it should still get some speedup on multi-cored CPUs. More advanced VMs with per-thread eden space would take a bit longer to write. Gulik. -- http://people.squeakfoundation.org/person/mikevdg http://gulik.pbwiki.com/

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Fwd: Web page with status of squeak license issue resolution?
by Damien Pollet 19 Mar '08

19 Mar '08

---------- Forwarded message ---------- From: José L. Redrejo Rodríguez <jredrejo(a)edu.juntaextremadura.net> Date: Tue, Feb 26, 2008 at 8:46 AM Subject: Re: Web page with status of squeak license issue resolution? To: Petter Reinholdtsen <pere(a)hungry.com> Cc: Damien Pollet <damien.pollet(a)gmail.com>, debian-edu(a)lists.debian.org El mar, 26-02-2008 a las 08:29 +0100, Petter Reinholdtsen escribió: > Hi. We spoke together after your lightning talk on FOSDEM about > getting squeak into Debian. You mentioned that there is slow progress > in getting the license question resolved, but that it is a lot of > work. Is there a web page documenting the status of this work? Like > who need to be contacted, who is already contacted and who is left to > contact? > > As I mentioned earlier, we in the Debian Edu community are interested > in including squeak into our distribution, and for this reason want to > see it in Debian/main. CC to our list to keep the other maintainers > updated on the squeak status. > > I've found <URL:http://wiki.squeak.org/squeak/159> and > <URL:http://wiki.squeak.org/squeak/3733> but did not see any > information there about the work on contacting previous authors to get > them to agree on a relicensing. > Those page are obsolete. The relicensing process is described and updated at http://wiki.squeak.org/squeak/6016 As the part of code that has not been relicensed is because contacting the authors has not been possible, current plans are rewritting that part of code. About taking Squeak in Debian, I have an ITP over the squeak virtual machine (#454635) and I plan to upload it as soon as I have time to finish a couple of pending patches for 64 bits platforms. There are different ways to use Squeak, people from squeak.org are more focused in using squeak as a development tool, and people from squeakland.org are more focused in using it for kids and teaching and currently working on the OLPC project. My intention is to do the squeak-vm interface oriented to teachers and students and give to the interface as better integration with the desktop as possible. For future Squeak images, as soon as the license issue is finished, we can work on different images. At Extremadura we have been working on customizing the image with a more updated interface, more eyecandy and adding projects from all around the world (Germany, Japan, Spain & USA) with a lot of educative tools. The project and the image is available at http://squeak.educarex.es. We have also made some interactive books for maths with the image. Those images are used in our school and will be uploaded to Debian when possible. So, in brief, today smalltalk developers are needed to recode the small part of code that has not been relicensed yet. There are some voices that say that FSF allows releasing under a free license if the percentage of code without the license is lower than 5%. If that were true it could be done today, but nobody is sure about it. Regards. José L. > Happy hacking, > -- > Petter Reinholdtsen > > -- Damien Pollet type less, do more [ | ] http://people.untyped.org/damien.pollet

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#fork and deterministic resumption of the resulting process
by Andreas Raab 16 Mar '08

16 Mar '08

Hi - In my never-ending quest for questionable behavior in multi-threaded situations just today I ran into a pattern which is dangerously common in our code. It basically goes like this: MyClass>>startWorkerProcess "worker is an instance variable" worker:= [self runWorkerProcess] fork. MyClass>>runWorkerProcess "Run the worker process" [Processor activeProcess == worker] whileTrue:[ "...do the work..." ]. MyClass>>stopWorkerProcess "Stop the worker process" worker := nil. "let it terminate itself" Those of you who can immediately tell what the problem is should get a medal for an outstanding knack of analyzing concurrency problems ;-) For the rest of us, the problem is that #fork in the above is not deterministic in the way that there is no guarantee whether the "worker" variable will be assigned when we enter the worker loop. It *would* be deterministic if the priority were below or above the current process' priority but when it's the same it can be affected by environmental effects (external signals, delay processing etc) leading to some very obscure runtime problems (in the above, the process would just not start). To fix this problem I have changed BlockContext>>fork and BlockContext>>forkAt: to read, e.g., BlockContext>>fork "Create and schedule a Process running the code in the receiver." ^self forkAt: Processor activePriority BlockContext>>forkAt: priority "Create and schedule a Process running the code in the receiver at the given priority. Answer the newly created process." | forkedProcess helperProcess | forkedProcess := self newProcess. forkedProcess priority: priority. priority = Processor activePriority ifTrue:[ helperProcess := [forkedProcess resume] newProcess. helperProcess priority: priority-1. helperProcess resume. ] ifFalse:[ forkedProcess resume ]. ^forkedProcess This will make sure that #fork has (for the purpose of resumption) the same semantics as forking at a lower priority has. What do people think about this? Cheers, - Andreas

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Ensuring canvas safety (using canvas by multiple processes)
by Igor Stasenko 15 Mar '08

15 Mar '08

The problem with OpenGL is, that GL context state is not a simple thing, which can be switched quickly. The drawing pipeline could be very complex, and if you allow multiple processes to issue drawing commands, it almost guaranteed that you will break things. Let me illustrate a problem. Suppose you have a Device, which provides a canvas which can be used to draw on it. canvas := Device getCanvas. " device at 'safe' state here " myVisuals drawThingsUsing: canvas. "device is not safe during drawing " " we finished drawing, now we are safe " .. the main problem, is that when you received a canvas instance you can free to do something like: canvas := Device getCanvas. 1 to: 10 do: [:i | [ (self at: i) drawOn: canvas ] fork ]. and at this point you are not safe anymore. You can easily break Device state, if multiple processes will try issue different drawing commands using canvas. I really don't like putting semaphores everywhere. It will be a performance killer. One way to isolate things, is to provide protocols like: Device drawExclusively: [:canvas | .. drawing code here .. ]. but again, this is not guarantees that, developer will not use received canvas reference to do nasty things.. Do an active process check in all methods of canvas? Any ideas? -- Best regards, Igor Stasenko AKA sig.

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[3.10] TaskList shortcut keys
by Noury Bouraqadi 14 Mar '08

14 Mar '08

Hi, I'm using Damien's nice sq3.10-7159dev08.01.1 image. To navigate from a task to another I found the shortcut keys: CMD +leftArrow or rightArrow. The problem is that it keeps switching from a task to the other if I keep the arrow key down. Relasing the arrow key makes the task list disappear. Is there some shortcut key to keep the TaskList displayed without switching between tasks ? Thanks, Noury ------------------------------------------------------------------ Dr. Noury Bouraqadi - Enseignant/Chercheur Responsable de l'enseignement de l'informatique ARMINES - Ecole des Mines de Douai - Dept. I.A. http://vst.ensm-douai.fr/noury European Smalltalk Users Group Board http://www.esug.org ------------------------------------------------------------------

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Election 2008: Answers from Yoshiki
by Yoshiki Ohshima 03 Mar '08

03 Mar '08

Hello, 1. Approximately, how much time do you plan on spending on Squeak during the coming year (in any kind of unit)? I will be still spending some chunk of my time constantly on the development of OLPC Etoys. Also, for making prototypes of new UI and end-user application, I'll be using Squeak (probably the OLPC Etoys image). In the longer term, though, VPRI trys to roll out new system that are not based on Squeak. I'll be working on these projects. 2. What are in your mind the three most important issues (not necessarily technical) we need to address in the coming year? Giving somebody(s) the authority of making technical dicisions would be important to move the community. 3. What is your view on fund raising and how any such collected money should be dealt with? For small chunks, simple donations from individuals members in the community would be good. But honestly I don't see some entity that offers bigger funding toward Squeak itself. There will be funding for projects that may use Squeak, but only if these projects are attractive. 4. What is your view on the ongoing process of making SqueakFoundation a not-for-profit legal entity? It is making progress and I hope it goes through. At the same time, even if it doesn't go through, that wouldn't be a disaster. It is people's willingness that drives the community. 5. Do you think the Team model is appropriate for organising our efforts or should we come up with something else? Team would work better if there is still a leader. 6. Do you have any specific views on how the Squeak board and the Squeak community should work together with the Squeak satellite communities (Croquet, Seaside, Sophie, Squeakland, Scratch etc), also referred to as "stakeholder communities"? Share the contributions and insights. Something like DeltaStream, which increases the visibility of other people's patches and let us cherry pick them would be good. I don't see a real merging effort of them will happen, though. I wouldn't even think about such effort with the OLPC Etoys image and the mainstream image. 7. The squeak.org release is our most important asset. How do you see it evolving over the next few years? For various reasons such as licensing and people's feeling toward minimum systems, I'd think that we would have two systems. One is based on a kind of small system that remotely related to current "Squeak". And another is maintenance versions of current image(s). The former should have cleaner license, but I think it is ok to distribute the latter even if some people think that the license is murky. 8. Do you have any thoughts on the current relicensing effort? I personally think that the license issue is overrated in the open source software community. Anybody can sue anybody after all for anything, so there is no way to achieve "100%" cleanness in this world. Nonetheless, we should try to do some "reasonable effort" to relicensing. And, like the Japanese versions and other languages version of Squeak and Squeakland, people wouldn't stop using, and that wouldn't be a problem. 9. How would you like Squeak to be positioned in the open source world in year 2012? An honest answer is that something much better comes out from the project at VPRI and the many members of Squeak community move on to it. 10. What do you see as the overall role of the board? Sometimes being at the Viewpoints helps, and knowing the POV of other language communities such as the largeer Japanese Squeak community helps. -- Yoshiki

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100 Million objects
by Herbert König 03 Mar '08

03 Mar '08

Hi, out of curiosity (forgot the reason) in a Workspace I did a:= Array new: 100000000 withAll: 1.0 Which gave me an 80% cpu usage. To verify I browsed a MessageTally and found that incremental GC used 88%. One Smalltalk garbageCollect brought things back to normal. As far as I remember my swiki readings this is because everything surviving a GC is moved to old space which is ignored by incremental GC. Another interesting observation: Doing the allocation with immediate GC is quite fast while doing a:= nil with immediate GC takes *much* longer. BTW, if you don't have the latest CPU 10 million objects will do. Win 3.10.6 VM, 3.8.2, 3.9 final and latest 3.10 images. Do I have to learn from this, that when creating lots of objects I intend to keep for a while, it's good to force a GC instead of waiting that time will move my objects to old space? Cheers Herbert mailto:herbertkoenig@gmx.net

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