August 2011 - Pharo-dev - lists.pharo.org

[Pharo-project] The serverMode flag and some thoughts on event polling
by Dimitry Golubovsky Aug. 26, 2011

Aug. 26, 2011

Hi, [this is not really about VM alone, but rather how image and VM interact - hence posting to multiple lists] In the process of porting Cog to Android, I observed the following pattern. If a scrollbar's "up" or "down" button is held pressed (prolonged tap on a button) for few seconds, the VM freezes, and gets killed by Android. Digging down the code got me to the WorldState>>interCyclePause: method. When there are morphs requesting stepping by shorter than certain time interval, the process responsibke for running step methods keeps looping without giving up to lower priority processes (and the host OS). ScrollBar seems to decrease the stepping interval over time to simulate accelerated scrolling. In order to port Cog to Android, I turned it into an event-driven VM based on ideas found in [1]. The same was done by Andreas for his earlier Classic VM port. My approach is a bit different such as the longjmp call is made as part of the relinquishProcessor primitive. Such primitive is called only from the lowest priority (idle) process which only can run when there are no external events to deal with. The event-driven VM needs to exit from the interpreter to the host process in order to obtain any input events. Thus, non-interrupted polling just deadlocks the interpreter as it cannot exit to the host process to get more events, yet keeps polling for them. The serverMode flag [2] (aka Mantis #6581) came to rescue. With such flag set to true, polling for events always yields CPU for 50ms (which in the Android case is meaningless anyway: I would not give the VM idle timer more often than 10 times per sec, so 50ms granularity is just not handleable). Anyway this does the trick as the lowest priority process gets its CPU time, and exits the interpreter to the host process. With serverMode = true I can tap a scroller button as long as I want, and even the text cursor in a workspace keeps blinking which means that stepping works and VM is alive. BTW in Android, the interpreter will be called as soon as any user action is intercepted, so responsiveness is not degraded regardless of the delay introduced by serverMode. I have found at least one place (this is in PharoCore) where serverMode is not honored: PolygonMorph class >> fromHand: (this method creates a polygon drawn by the mouse) This method has code pieces (repeating multiple times btw - why is it not a separate method?) [Sensor anyButtonPressed] whileFalse: [self currentWorld displayWorldSafely; runStepMethods]. which is clearly grabbing the event sensor to the polygon morph while keeping other morphs stepped, so the VM does not seem dead entirely. In my case though executing PolygonMorph fromHand: defaultHand freezes the VM immediately as this is uninterrupted polling again. While I'll try to experiment with inserting interCyclePause somewhere in these loops, there are broader questions on how event polling is done these days: 1. Are there other morphs in packages not included in PharoCore where event grabbing is done such way? 1a. Is this possible in general to have such functionality properly embedded in WorldState instead of having it in a morph itself, if event grabbing is needed? 2. Are there images in active development (other than PharoCore, and Squeak) where event polling is done without an option to relinquish processor? In fact, this VM freezing on stepping morphs was a big issue, and it mainly kept me from moving towards the public release. Now that it seems to be solved (unless there is a flaw in my logic above) it takes me closer to finishing the Cog for Android port. Thanks. ------------------------------------------ [1] http://lists.squeakfoundation.org/pipermail/vm-dev/2009-November/003385.html [2] http://bugs.squeak.org/view.php?id=6581 -- Dimitry Golubovsky Anywhere on the Web

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[Pharo-project] CI down?
by Pavel Krivanek Aug. 26, 2011

Aug. 26, 2011

The CI server https://ci.lille.inria.fr/pharo/ is not responding. Is it down? -- Pavel

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Re: [Pharo-project] [Vm-dev] Cog in Jenkis has brokken finalization
by Marcus Denker Aug. 26, 2011

Aug. 26, 2011

On Aug 25, 2011, at 5:34 PM, Igor Stasenko wrote: > On 25 August 2011 14:38, Mariano Martinez Peck <marianopeck(a)gmail.com> wrote: >> >> Hi guys. The linux Cog VM from hudson has broken the finalization. Just run the WeakRegistryTest and you will see the broken test. It might happened because of the ephemerons because Eliot's VM works correctly. >> Even more, the VM from Jenkis is correct. So....I would remove the broken one from Hudson. >> > > I migrated unix and windows VM jobs to Jenkins. > Please use VMs built on Jenkins servers. > Can we delete the Hudson projects? Just to avoid confusion? -- Marcus Denker -- http://marcusdenker.de

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[Pharo-project] Filesystem in collab book
by Max Leske Aug. 26, 2011

Aug. 26, 2011

I wrote a few lines on Filesystem in the collab book: http://book.pharo-project.org/book/PharoTools/Filesystem/ Please take a look and let me know if you'd like to see any changes. Cheers, Max

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[Pharo-project] Cog in Jenkis has brokken finalization
by Mariano Martinez Peck Aug. 25, 2011

Aug. 25, 2011

Hi guys. The linux Cog VM from hudson has broken the finalization. Just run the WeakRegistryTest and you will see the broken test. It might happened because of the ephemerons because Eliot's VM works correctly. Even more, the VM from Jenkis is correct. So....I would remove the broken one from Hudson. Cheers -- Mariano http://marianopeck.wordpress.com

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[Pharo-project] HelpSystem added to CollaborActive book
by Sean P. DeNigris Aug. 25, 2011

Aug. 25, 2011

A short description by its creator, Torsten. And a link to the PharoCast. http://book.pharo-project.org/book/PharoTools/HelpSystem Sean -- View this message in context: http://forum.world.st/HelpSystem-added-to-CollaborActive-book-tp3768092p376… Sent from the Pharo Smalltalk mailing list archive at Nabble.com.

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[Pharo-project] expanding text morph
by Tudor Girba Aug. 25, 2011

Aug. 25, 2011

Hi, I would like to create a Text Morph that wraps the text horizontally, and expands the height to fit the text. Thus, this morph would never offer scrolling. How could I do that? Cheers, Doru -- www.tudorgirba.com "There are no old things, there are only old ways of looking at them."

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[Pharo-project] new Cog VMs available
by Eliot Miranda Aug. 25, 2011

Aug. 25, 2011

in http://www.mirandabanda.org/files/Cog/VM/VM.r2487/. Fix bugs described in the "[Pharo-project] Troubles with #flushCache and #run:with:in:" thread http://lists.gforge.inria.fr/pipermail/pharo-project/ 2011-July/050858.html. The PIC machinery wrongly treated invoke-as-method sends as MNUs. Closely related, finally fully implement PIC MNU cacheing where, by calling a special abort, a PIC is able to record that a gven selector is an MNU for a particular class. Speeds up a simple MNU benchmark by 33% (with more performance the deeper the receiver's cass hierarchy is). On Mac fix mis-editing of Info.plist to insert revision info so that VM .app once again starts on 10.5.x. -- best, Eliot

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[Pharo-project] Using system fonts in Pharo
by Ilmari Vacklin Aug. 24, 2011

Aug. 24, 2011

Using Pharo 1.3, I'm trying to load system fonts into the image. However, if I the "Launch" button next to "Update fonts from system", nothing seems to happen. What is the expected behaviour of the button?

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[Pharo-project] Slides of Pharo Roadmap talk Monday
by Marcus Denker Aug. 24, 2011

Aug. 24, 2011

SlideShare: http://www.slideshare.net/esug/pharo-roadmap PDF: http://esug.org/data/ESUG2011/Slides/22-Monday/03-22-ESUG-PharoRoadmap.pdf -- Marcus Denker -- http://marcusdenker.de

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