April 2017 - Pharo-dev - lists.pharo.org

Esteban's ChangeLog week of 27 March 2017
by estebanlm＠gmail.com April 3, 2017

April 3, 2017

Hello! This is my weekly ChangeLog, from 27 March 2017 to 2 April 2017. You can see it in a better format by going here: http://log.smallworks.eu/web/search?from=27/3/2017&to=2/4/2017 ChangeLog ========= 31 March 2017: -------------- * Yesterday I spent most of the day verifying why the pharo site was going down time to time... as a result, we found a problem in Voyage that may cause a deadlock under heavy load. Finally, with the help of Guille we help a possible cause in the way the +VOLazyProxy+ is implemented. This is +#doesNotUnderstand:+ current implementation: ---- VOLazyProxy>>doesNotUnderstand: aMessage | realObject | realObject := self obtainRealObject. realObject ifNil: [ (repository descriptionBuilder for: objectClass) isAllowMissingContent ifTrue: [ realObject := VOMissingObject class: objectClass id: objectId ] ifFalse: [ VOError signal: ('Lazy reference not found {1}: {2}' format: {objectClass name. objectId}) ] ]. VOLazyProxy mutex critical: [ self == realObject ifFalse: [ self becomeForwardKeepingHash: realObject ] ]. ^realObject perform: aMessage selector withArguments: aMessage arguments. ---- It is designed to prevent double attempt to become when trying to access same proxy at concurrent moments (in webapps is very frequent). We discovered this implementation has some problems: * When doing the comparisson of of +self+ with +realObject+ self can already be in the stack, and then it can fail. * apparently the error handler handles the occurrence of +Semaphore+ in a stack in weird ways (to ensure is debuggable) :) So, now I'm testing (and proposing to Voyage) this implementation: ---- VOLazyProxy>>#doesNotUnderstand: aMessage | realObject thisObject error | realObject := self obtainRealObject. realObject ifNil: [ (repository descriptionBuilder for: objectClass) isAllowMissingContent ifTrue: [ realObject := VOMissingObject class: objectClass id: objectId ] ifFalse: [ VOError signal: ('Lazy reference not found {1}: {2}' format: {objectClass name. objectId}) ] ]. error := nil. thisObject := self. VOLazyProxy mutex critical: [ thisObject == realObject ifFalse: [ [ self becomeForwardKeepingHash: realObject ] on: Error do: [ :e | error := e ] ] ]. error ifNotNil: [ VOLazyProxyBecomeError new error: error; signal ]. ^realObject perform: aMessage selector withArguments: aMessage arguments. ---- If this works, I will submit an update to [Voyage](http://github.com/pharo-nosql/voyage) immediately :) 29 March 2017: -------------- * I validated some changes to Athens and copyBits primitive to fix the crashing problem. Seems to be working so I will integrate it... thanks Eliot! * Still with [Iceberg](https://github.com/npasserini/iceberg), I took care of some bug... but most important than that, I added an option to create repositories from Iceberg. This is very simple: you click in the "New repository" button :) This way you do not need a remote repository to start working, and you can keep your versions in your local environent if you want. *WARNNING*: When doing your first push, it has to be a clean push (fast-forward), I have had problems trying the otherwise (which triggered a merge that Iceberg still does not knows how to handle). 27 March 2017: -------------- * I just spent sometime fixing stuff on [Iceberg](https://github.com/npasserini/iceberg). * I fixed [issue 313](https://github.com/npasserini/iceberg/issues/313) (now user gets a dialog to set user properties when needed). * Now commit dialog remembers last choice of "push" automatically while commiting. cheers! Esteban

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[gsoc] Advances in Code Quality
by Myroslava Romaniuk April 2, 2017

April 2, 2017

Hello, I'm Myroslava and I'm studying Computer Science at the Ukrainian Catholic University in Lviv. As part of my Google Summer of Code project I'm going to work on the quality of code in Pharo. This <https://docs.google.com/document/d/1cX7VJ2QZejq_Cu6Ur28UCiUwzSD-Bu8GgSDqECi…> is my proposal draft, and I would really appreciate some feedback, comments, suggestions and so on. Thanks!

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Removing a class something messes up Nautilus
by Stephane Ducasse April 2, 2017

April 2, 2017

Hi In latest pharo 60 I'm removing a lot of classes when I experiment with Smacc (which leak some references to class too btw). And I see form time to time the package empty and does not refresh. I have to open another nautilus to see the classes in the package. Stef

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Iceberg with SSH on Linux
by Pavel Krivanek April 2, 2017

April 2, 2017

Hi, I want to let you know that the SSH (git@...) support in Iceberg on Linux VM now works with the latest threaded VM (get.pharo.org/vmTLatest60) The threaded VM now runs without root priviledges nor special configuration of the system. Thank you Esteban and others! Cheers, -- Pavel

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[Gsoc] [FastTable improvements] [Features request]
by Elhamer Oussama AbdelKHalek April 1, 2017

April 1, 2017

Dear Pharo community, I am planning in working on FastTables improvements during Gsoc as suggested by Mr. Stephan Eggermont. Iâve managed to collect some important features and ideas suggested by some of you (thanks to @stephan, @cyrilferlicot, @thierrygoubier, @estebanlm, @jfabry) in the following repo (as issues): https://github.com/SamTheDev/Pharo-FastTable-improvements/issues You might come across some FT limitations or issues while working with Pharo as a user or as a contributor, I would appreciate hearing your thoughts on this, please feel free to share your reviews/ideas/requests â¦ on the repo. Thank you for your contribution, Elhamer.

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(non)prefixes of Spec classes
by Peter Uhnak April 1, 2017

April 1, 2017

I suppose this applies to other tools/frameworks as well, but is it beneficial to have non-prefixed classes in the system? e.g. in Spec we have WindowModel, AbstractAdapter, TreeModel, ... I am not asking because I want these generic terms free, but rather to be more explicit about the classes being from Spec. Is there any "official" view or preferred view on this? Thanks, Peter

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[VM] Windows VM SurfacePlugin.dll LoadLibrary failure
by Peter Uhnak April 1, 2017

April 1, 2017

Hi, recently (couple of days ago) sometimes when I start Pharo there's a box at the bottom "Debug console" with the following info ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # Debug console # To close: F2 -> 'debug options' -> 'show output console' # To disable: F2 -> 'debug options' -> 'show console on errors' LoadLibrary(SurfacePlugin) (998: Invalid access to memory location. ) LoadLibrary(SurfacePlugin.dll) (998: Invalid access to memory location. ) LoadLibrary(SurfacePlugin) (998: Invalid access to memory location. ) LoadLibrary(SurfacePlugin.dll) (998: Invalid access to memory location. ) LoadLibrary(SurfacePlugin) (998: Invalid access to memory location. ) LoadLibrary(SurfacePlugin.dll) (998: Invalid access to memory location. ) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I have Windows 10 & VM Version: Cog Spur VM 5.0 (release) from Feb 3 2017 (downloaded from files.pharo.org) This error results in Athens (and Roassal) not working, although Pharo itself seems fine. Reopening the image has no effect, and the only resolution is to do a system reboot. There is also crash.dmp from Feb 12 (possibly the day it started) containing ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Sun Feb 12 23:10:24 2017 Exception code: C0000005 Exception addr: 0040BDD0 Access violation (write access) at 00AFF43C EAX:FFFFFFFF EBX:74329850 ECX:549D7EBE EDX:00AFF43C ESI:74315F70 EDI:00489DB9 EBP:0887FF94 ESP:0887FF54 EIP:0040BDD0 EFL:00010206 FP Control: 0000027F FP Status: 00000000 FP Tag: 0000FFFF Crashed in some other thread ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Makes me wonder whether the SurfacePlugin.dll didn't somehow get corrupted... but then again there's no modification date change on the dll file, nor would it explain why rebooting fixes it. Thanks, Peter

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