Squeak-dev July 2007

squeak-dev@lists.squeakfoundation.org

140 participants
214 discussions

Error updating universe list
by Torsten Bergmann 28 Aug '07

28 Aug '07

Giuseppe wrote: >I'm getting this error updating universe from network from different >images. Looks like "Seaside-HTML5-beta version 2.8.411.5" (http://www.squeaksource.com/Seaside/HTML5-pmm.5.mcz) was added with a conflict - but the package defined in the conflict is empty: <package> <name>Seaside-HTML5-beta</name> <version>2.8.411.5</version> <category>Web Development beta</category> <description>HTML5 support moved out of Seaside2.8</description> <url>http://www.squeaksource.com/Seaside/HTML5-pmm.5.mcz</url> <homepage>http://www.seaside.st/</homepage> <maintainer>keith_hodges(a)yahoo.co.uk</maintainer> <provides></provides> <depends> <packagename>Seaside-beta</packagename></depends> <conflicts> <packagename></packagename></conflicts></package> -- Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser

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Squeak@ECOOP
by Marcus Denker 21 Aug '07

21 Aug '07

Hello, Squeak Germany e.V. and c-base are inviting for a special Squeak BOF event next week: When? 31.07.2007, starting at 19:30 Where? c-base (rungestrasse 20 10179 berlin, Germany, Europe) More information: http://upcoming.yahoo.com/event/222385 The event will be at c-base, see http://c-base.org. We have a seminar room, there will be live music in the main hall later in the evening, see http://www.openstage-berlin.de/ This is outside of ECOOP, so it is possible to attend without a conference registration! And it's not Squeak only: everyone is invited. C-Base is ca. 20min by s-bahn from the main ECOOP site. For conference participants, we will organize to go together, more information will be posted at the conference. The Dyla 2007 Workshop is the same day: http://dyla2007.unibe.ch/ See you in Berlin! Marcus pls. CC: me on any answers to this email, as I am not reading the mailinglist right now. -- Marcus Denker -- denker(a)iam.unibe.ch http://www.iam.unibe.ch/~denker

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Mock-Framework for Squeak?
by Robert Krahn 15 Aug '07

15 Aug '07

Dear Squeakers, I was looking for a Mock-Framework for Smalltalk but noticed that there is only SmallMock (http://www.cincomsmalltalk.com/blog/blogView?showComments=true&printTitle=S…) which seems to be outdated and not available any more. Have I missed something or are there really no mocks for Squeak? I thought of something like SMock (http://www.macta.f2s.com/Thoughts/smock.html). Thank you, Robert

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PDAMorph
by Brad Fuller 10 Aug '07

10 Aug '07

At one time in the recent past Tim R. suggested looking at the PDA project that he and Dan did. I did. but, now I can't find where I put it! There is a package called PDAMorph on squeaksource but it requires "WatchMorph". Is that available? Or, where can I find the PDA source? Or, is PDAMorph even the right package? Tim? thanks, brad

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Morphic! (ans to Jason from previous thread)
by Jerome Peace 09 Aug '07

09 Aug '07

Morphic! (ans to Jason from previous thread) My previous attempt to post this was only partially successful. This is the full post. -Jer Hi Jason, Thanks for your interest. Spec means speculation and doing something on spec means you take the responsibility that it might or might not be accepted by the publisher. The other way to do something is on commission where others specify what you are to do but give a garantee that the work will be of use to them and you will be compensated. As for motivation for morphic work, for me it means the work must be interesting (as defined by my curiosity) lead to something I think elegant in the code and the behavior of the morphs and allow me to learn and grow in my own understanding of squeak, morphic and things larger. You apparently have the curiosity streak as well. So answer me this, and I can better advise you. What would you like to learn from reading the specifications? you thought I had mentioned? What would you like to be able to do with the knowledge? Often, instead of specifications, I find it useful to just write down what I want to see squeak do. As vaguely as my initial understanding permits. As briefly as I can fit all my ideas in. And as passionately as the forces of desire inside me wish for the feature to exist. Oddly, the rest of it is all downhill from there. The specifications become the detailing of the initial statement. The code comes from implementing pieces of the details, testing them and proving they work. The fun comes when the coding process leads to something unexpected and the detail or even the original statement becomes worth rewriting. Incremental design benifits the designer by educating him all along the way. (Look on the web for articles about McReadys gossamer condor.) Anyway thanks for your response and request. Its been fun writing this. Yours in curiosity and service, --Jerome Peace ____________________________________________________________________________________ Sick sense of humor? Visit Yahoo! TV's Comedy with an Edge to see what's on, when. http://tv.yahoo.com/collections/222

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License change process
by Pavel Krivanek 03 Aug '07

03 Aug '07

Hi all, small notes to the relicensing effort. Please see http://lists.squeakfoundation.org/pipermail/squeak-dev/2007-July/119133.html. As you maybe know, the main idea is to have relatively small image that contains only free code and that is able to load the rest of current Squeak. I have selected about 3000 methods that can do this job and started with the license change of the code: 1) code from all the people that signed the license agreement is free 2) some methods with non-standard initials were fixed (initialsFix.st) to generate valid table of authors 3) this initials are considered to be free: ab jm sma fbs BP MD md sd NouryBouraqadi stephaneducassse tpr. That are mostly initials of known authors in a different form. 4) I compared the code with the code of free Squeak 1.1 and if the code was the same and had no author, I added this comment: "from Squeak 1.1". Such methods have new initials (pk). 5) if the method has the same code as in Squeak 1.1 but initials of a contributor that haven't signed the agreement, it includes comment like: "from Squeak 1.1, reformated by Andrew C. Greenberg". The new initials are mine again. 6) The most problematic is the rest of non-free code. You may find the list of this methods here: http://comtalk.net/public/pub/KernelImage/license/ (odf table, pdf) It's 316 methods. Some of them are simple accessors and are very easy to rewrite - there's the special column with this information. The next column contains original free code from Squeak 1.1 (if any). It is always somehow different from the current version. I have created next column with comment information that says how the original method should be changed. For example it says that the ZeroDivide class should be used instead of general error etc.. Of course some methods aren't easy to rewrite (comments like significant changes or different code). So I'm looking for a good soul that wants to help and will write this accessors and will modify the original methods where the information enable it. This person must not see current versions of this methods! That's why I cannot do that by myself. Then we will have got about 200 kernel methods to rewrite. We need to build two teams for that task: - one group of people will read the current code and will write tests that will specify the functionality of the methods (plus maybe some useful comments or hints) - the second group will write the new implementation. The members of this group must not see the current implementation. As the bonus to the free kernel we will have got more tests. I think that this is the best way how to correctly change the license of non-free Squeak code. If you have better idea, tell me. So, volunteers? ;-) Chees, -- Pavel

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Whisker browser / Certification on squeak people?
by Simon Guest 03 Aug '07

03 Aug '07

Hi, I'm just recently getting into Squeak more seriously, having been dabbling for a while. I'm a maths teacher, currently using Squeak as a demonstration tool in the classroom, and generally enjoying messing around with it. (I used to develop software for a living, in other languages.) Anyway, having just discovered the Whisker browser, I've now been saved from death by 1000 windows. Thank you, Doug! I'd like to register my interest in Whisker on Squeak People, for which I seem to need to be certified as an Apprentice. So, if anyone recognises me from my few previous posts here - mostly questions, and a contributed bugfix or two on Mantis, I'd be grateful for a certification on Squeak People, where I'm known as sjg. cheers, Simon

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How to generate identically image file after snapshots
by Martin Troielli 02 Aug '07

02 Aug '07

Hi All, We have tried to produce the same (bit identically) image file after two consecutive snapshots. We start from a base image then, fileIn several files into it and finally, we just SmalltalkImage current snapshot: true andQuit: true. We need this to verify the image file generated by a third-party with a checksum by executing a script. After trying several ways to get it (even by scripting the fileIn process and the snapshot), we found that the image files have, beside the timestamp differences, thousands of other differences and sometimes the snapshots have also size differeces. We supose that this kind of issues may occur due to the GC activity. Are this issues from the way GC process is changing dynamically the memory bytes? There is a way to inhibite this activity? Attached are the scripts we use to produce the image files. Many thanks in advance, Martin Troielli

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Symbol allInstances
by Philippe Marschall 02 Aug '07

02 Aug '07

Hi Browsing through a 3.9 image I found three senders of Symbol allInstances which store the result in a temp during image segment export: ImageSegment >> #copySmartRootsExport: CodeLoader >> #exportCodeSegment:classes:keepSource: SystemDictionary >> #writeImageSegmentsFrom:withKernel: Is this a problem? Cheers Philippe

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Delay and Server reliability
by Andreas Raab 02 Aug '07

02 Aug '07

Hi - We recently had some "fun" chasing server lockups (with truly awful uptimes of about a day or less before things went downhill) and were finally able to track a huge portion of it down to problems with Delay. The effect we were seeing on our servers was that the system would randomly lock up and either go down to 0% CPU or 100% CPU. After poking it with a USR1 signal (which, in our VMs is hooked up such that it prints all the call stacks in the image; it's a life-safer if you need to debug these issues) we usually found that all processes were waiting on Delay's AccessProtect (0%) or alternatively found that a particular process (the event tickler) would sit in a tight loop swallowing repeated errors complaining that "this delay is already scheduled". After hours and hours of testing, debugging, and a little stroke of luck we finally found out that all of these issues were caused by the fact that Delay's internal structures are updated by the calling process (insertion into and removal from SuspendedDelays) which renders the process susceptible to being terminated in the midst of updating these structures. If you look at the code, this is obviously an issue because if (for example) the calling process gets terminated while it's resorting SuspendedDelays the result is unpredictable. This is in particular an issue because the calling process is often running at a relatively low priority so interruption by other, high-priority processes is a common case. And if any of these higher priority processes kills the one that just happens to execute SortedCollection>>remove: anything can happen - from leaving a later delay in front of an earlier one (one of the cases we had indicated that this was just what had happened) to errors when doing the next insert/remove ("trying to evaluate a block that is already evaluated") to many more weirdnesses. Unfortunately, it is basically impossible to recreate this problem under any kind of controlled circumstances, mostly because you need a source of events that is truly independent from your time source. As a consequence of our findings we rewrote Delay to deal with these issues properly and, having deployed the changes about ten days ago on our servers, all of these sources of problems simply vanished. We haven't had a single server problem which we couldn't attribute to our own stupidity (such as running out of disk space ;-) The changes will in particular be helpful to you if you: * run network servers * fork processes to handle network requests * terminate these processes explicitly (on error conditions for example) * use Semaphore>>waitTimeoutMsecs: (all socket functions use this) If you have seen random, unexplained lockups of your server (0% CPU load while being locked up is a dead giveaway[*]) I'd recommend using the attached changes (which work best on top of a VM with David Lewis' 64bit fixes applied) and see if that helps. For us, they made the difference between running the server in Squeak and rewriting it in Java. I've also filed this as http://bugs.squeak.org/view.php?id=6576 [*] The 0% CPU lockups have sometimes been attributed to issues with Linux wait functions. After having seen the havoc that Delay wrecks on the system I don't buy these explanations any longer. A much simpler (and more likely) explanation is that Delay went wild. Cheers, - Andreas

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