October 2010 - Pharo-dev - lists.pharo.org

Re: [Pharo-project] Hallo Pharoers.. namespaces in the system level ?
by StÃ©phane Ducasse Oct. 11, 2010

Oct. 11, 2010

> > > Stef and I worked on an implementation a few years ago. > http://www.squeaksource.com/Namespace.html And it is a bad one :) Now we are working on making the system environment-aware so that we can browse part of the system, (remotely too with you). Stef > > Cheers, > Alexandre > > > On 11 Oct 2010, at 07:53, Nick Papoylias wrote: > >> Hallo to all, >> >> I am starting my Ph.D on 'languages and environments for autonomous robotics' -- and pharo will be a huge part of it. >> >> I am currently playing around with the system (to get the feel of it..) and testing it's programming tools in the context of >> different namespaces / environments. >> >> Specifically I am trying to find out what the implications of having a remote environment over rST for e.g (to browse, debug e.t.c). >> >> Any pointers to related work, suggestions e.t.c are welcomed. >> >> So my question: >> >> Is anybody currently working on integrating namespaces in the system level ? I may have one or two questions and suggestions to make. >> >> Thank you very much ! >> >> Nick Papoulias >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > -- > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > Alexandre Bergel http://www.bergel.eu > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

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[Pharo-project] [update 1.2] #12189
by StÃ©phane Ducasse Oct. 11, 2010

Oct. 11, 2010

12189 ----- - Issue 2883: Anymorphic Style. Thanks Anymorphic and Nicolas Paez. - Issue 2979: Controlling UI feedback. BlockClosure>>silentlyValue

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Re: [Pharo-project] MicroSqueak [was System Tracer]
by Eliot Miranda Oct. 11, 2010

Oct. 11, 2010

FInd attached. You want MicroSqueak-colonequal.st and the various MSqueak-.st files. This produces a 57k image. John's also given me a 2.0 development image which will run on a 3.8 VM. Let me know if you want that. For me this is a proof of concept. What's needed is to define a headless core that contains the compiler, good error reporting to standard out, the core collection and numeric libraries and file support. Then we try and load packages into it and build up a headful image. On Wed, Oct 6, 2010 at 3:03 PM, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>wrote: > > On Oct 6, 2010, at 7:18 PM, Eliot Miranda wrote: > > > > > > > On Wed, Oct 6, 2010 at 7:31 AM, StÃ©phane Ducasse < > stephane.ducasse(a)inria.fr> wrote: > > generate a new image. > > > > But that's not what it does. > > Yes I know gnerates = clone in my mail. > > > t merely clones an image, which is a long way form building an image > form source. *That*'s a useful project. John Maloney's lovely MicroSqueak > is a good starting point for ideas (basically have a copy of a kernel subset > of the system in a namespace and generate a fresh image from that). > > Do you have a pointer on the code of john. We are looking at bootstrap code > right now. > > > > > On Oct 6, 2010, at 2:23 PM, Alexandre Bergel wrote: > > > > > Hi! > > > > > > What do you want to achieve? > > > > > > Cheers, > > > Alexandre > > > > > > > > > On 6 Oct 2010, at 05:36, Gabriel HernÃ¡n Barbuto wrote: > > > > > >> Hi > > >> > > >> Does anyone know where I can find the system tracer that is currently > > >> in use in Pharo? > > >> > > >> Bests > > >> Gabriel > > >> > > >> _______________________________________________ > > >> Pharo-project mailing list > > >> Pharo-project(a)lists.gforge.inria.fr > > >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > > > > -- > > > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > > > Alexandre Bergel http://www.bergel.eu > > > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > Pharo-project mailing list > > > Pharo-project(a)lists.gforge.inria.fr > > > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > > > > _______________________________________________ > > Pharo-project mailing list > > Pharo-project(a)lists.gforge.inria.fr > > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > > _______________________________________________ > > Pharo-project mailing list > > Pharo-project(a)lists.gforge.inria.fr > > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >

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[Pharo-project] WeakRegistry>>remove: - when you'll be in trouble
by Igor Stasenko Oct. 11, 2010

Oct. 11, 2010

A current implementation of this method remove: oldObject ifAbsent: exceptionBlock "Remove oldObject as one of the receiver's elements." oldObject ifNil: [ ^nil ]. ^(self protected: [ valueDictionary removeKey: oldObject ifAbsent: nil ]) ifNil: [ exceptionBlock value ] simply removes a previously registered object from registry and voila. Now lets get back to our discussion about multiple finalizers per object and using them in weak subscriptions etc. Suppose i am added a socket to weak registry, and suppose i am added a weak subscription to it. Now, if i do 'socket close' , it tells weak registry to remove it from list. And what we'll have: - socket handle is closed - socket is wiped from weak registry - but weak subscription still listed somewhere in a list of subscriptions My suggestion is, that upon #remove:, a weak registry should notify all executors that object of interest are no longer takes part in finalization scheme, so they should not count on receiving #finalize eventually. In other words: remove: oldObject ifAbsent: exceptionBlock "Remove oldObject as one of the receiver's elements." oldObject ifNil: [ ^nil ]. ^(self protected: [ | executor | executor := valueDictionary removeKey: oldObject ifAbsent: nil. executor discardFinalization. ]) ifNil: [ exceptionBlock value ] -- Best regards, Igor Stasenko AKA sig.

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Re: [Pharo-project] Compiler pedantic about ifNotNil: argument
by StÃ©phane Ducasse Oct. 11, 2010

Oct. 11, 2010

>> >> >> Now to me this looks like a hack and again it works because now Symbol are valuable objects. >> Too many hacks will only make the system more hackish. >> And especially the >> iftrue: 'foo' ifFalse: 'zork' >> > > This is not a hack, because if you refer to implementation: > > True>>ifTrue: trueAlternativeBlock ifFalse: falseAlternativeBlock > ^trueAlternativeBlock value > > False>>ifTrue: trueAlternativeBlock ifFalse: falseAlternativeBlock > ^falseAlternativeBlock value > > so, it answers either 'foo' value , or 'zork' value. > And #value could be sent to any object in system: > > Object>>value > ^self > > What actually shown here is a use of duck typing, because any object, > which implemets #value, could be safely passed > as argument to #ifTrue:ifFalse: message. > It is well consistent with language design. I know well that. and it sucks from a language semantics point of view. I agree with the mail of lukas. Stef

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Re: [Pharo-project] Compiler pedantic about ifNotNil: argument
by StÃ©phane Ducasse Oct. 11, 2010

Oct. 11, 2010

On Oct 11, 2010, at 1:28 PM, Lukas Renggli wrote: >> Object>>value >> ^self >> >> What actually shown here is a use of duck typing, because any object, >> which implemets #value, could be safely passed >> as argument to #ifTrue:ifFalse: message. >> It is well consistent with language design. > > Magritte implemented Symbol>>#value: for a while before any Smalltalk > had this is their standard library. I must admit that I liked it in > the beginning, but in the long run I realized that ... > > 1. It is not easily understandable for newbies. > 2. It quickly leads to very unreadable, hard to understand and hard to > refactor code. > 3. It is very limiting in itself and quickly leads to other hacks > (like to replace sort blocks). > 4. #value and friends should be only understood by objects that can be > evaluated (certainly not by Object). A symbol (name) by itself cannot > be evaluated. + 200 > I eventually removed Symbol>>#value: for good. Re-occuring questions > in the mailing list disappeared. > > Therefor I strongly suggest to remove #value, #value:, and friends > from all objects that are not self-evaluable. BlockClosure and > MessageSend are self-evaluable. Only there it makes sense. > > If people are too lazy to create a block where something > self-evaluable is needed they should use a programming language > designed for cryptic code. Creating a block closure in Smalltalk is > concise and makes clear what happens easily. A symbol does not, you > need to exactly understand how this dispatches with various objects. This is exactly my point. Especially for system API like ifNotNil: When I read self bar: #zook I just know ok we are just passing a symbol as argument. I do not have to rely on the semantics of bar: so this is the only conclusion I can draw. Now I do not want to force people to have to understand the semantics of each single selector. In addition, it breaks nice rule such as use [ ] for any place where you do not know if the code will be executed. Simple nice and beautiful. [..]s delay execution and let the guy control it. Stef

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Re: [Pharo-project] Migration Manual for Pharo 1.1 ?
by StÃ©phane Ducasse Oct. 11, 2010

Oct. 11, 2010

Hi we should improve from that side, but unfortunately we do not have enough man power to build tool that could support it. Stef On Oct 11, 2010, at 1:28 PM, Johannes Rasche wrote: > Hi Folks, > > I just wanted to install my work on version 1.1 and was surprised > to discover changes which leave me alone to find out for myself how to change my code : > > WorldMenu (I wrote a subclass of PasteUpMorph) > NaturalLanguageTranslator (what is the "gettext package" mentioned in the class comment? - cannot find a menu to edit translations - hidden sowhere?) > > possibly more surprises to come .... > > some backwardcompatibilty support would have been nice > and > some examples > > But I like to point out as well, that Pharo is improving from release to release - thanks for that !!!! > > Thanks in advance > > > > > Johannes Rasche > Hagelberger Str. 56 > 10965 Berlin > > mail: johannesrasche(a)me.com > skype: johannesrasche > www: http://myNeat.de > fon: +49-30-7469 4425 (skypeIn) > fax: +49-30-315 66 821 > > > > > > > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

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[Pharo-project] another little OB "bug"
by Mariano Martinez Peck Oct. 11, 2010

Oct. 11, 2010

Hi. Me again. Not sure if it is a bug but I don't like it. If you do, no problem then ;) Suppose you are working with a method that it is in the half of the method pane of OB. Once you save it or run test on it for example, the "scroll" and the method pane is updated so that THAT method is first, above. And sometimes this is quite annoying for me. Cheers Mariano

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[Pharo-project] Xtreams : first embryonary port on Squeak
by Nicolas Cellier Oct. 11, 2010

Oct. 11, 2010

So, I started a quick port of VW Xtreams to Squeak this evening. Only the Xtreams-Core and the trivial Xtreams-Terminals (no file/pipe/socket/pointer). You'll find code at http://www.squeaksource.com/XTream. My previous experimental Xtream project has been renamed SqueaXTream to reduce confusion, but still sits in the same project. Please find my report below. cheers Nicolas --------------------- REPORT --------------------- THE CONTENTS: This first port is made of 3 packages - Xtreams-Core - Xtreams-Terminals - Xtreams-VWCompatible Plus 2 tests - Xtreams-CoreTests - Xtreams-TerminalsTests Please notice I removed one hyphen from test package names for MC compatibility. THE PROCEDURE: I didn't use FileOut30 not any more advanced tool, but just a simple copy/paste strategy. This gave me a chance to do a fast review of code. For porting the future evolutions of VW Xtreams, more advanced tools will be necessary, the manual approach does not scale. THE MODIFICATIONS: The changes I made are quite restricted, which indicates that Xtreams is not that hard to port. Main changes are due to lack of namespace in Squeak: - I added a XT prefix to every Xtreams classes (no Namespace in Squeak) - I added XTPools, a SharedPool for holding the single Xtreams namespace variable DefaultBufferSize - I transformed class SharedVariables into class variables and added proper class side initialization for these in XTWriteStream For the rest, I tried to not change Xtreams contents. but rather did implement VW compatible messages when possible in the Xtreams-VWCompatible package when they did not exist in Squeak. These message are a full rewrite and are also released under MIT license. The few exceptions are: - I modified originator -> self originator in XTIncomplete. - I changed the senders of #newInFixedSpace: to rather send an #error: 'not implemented in Squeak' in XTRecyclingBuffer - I replaced #waitIfCurtailedSignal/#signal with a #critical: section in XTRecyclingBuffer - I replaced Core.Timer after:do: with self after:do: in Xtreams-CoreTests A DISCUSSION OF TECHNICAL DETAILS: I first attempted to replace #growToAtLeast: with #grownBy: because Squeak become: is notoriously inefficient. But obviously, this did not work, the tests rely on destination preserving its identity. This clearly is going to degrade micro benchmarks when the destination collection capacity is not well adjusted in advance. I think we should discuss this particular point. Is identity preservation absolutely required, or just convenient ? THE STATUS OF TESTS: Tests do not all pass. There seems to be a bug in Squeak #replace:from:to:with: when the replacement is the collection itself, moved to the right (this is with a COG VM). THE FUTURE: I will probably continue porting with reduced activity, so I invite any interested person to help. Right now, the project is world writeable, code commited here falling under MIT license.

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Oct. 11, 2010

Thanks. So let's see what is the best choice and tell us. On Oct 11, 2010, at 11:47 AM, Igor Stasenko wrote: > On 11 October 2010 12:10, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> wrote: >> I integrate >> Issue 3086: MCMethodDefinition>>shutdown hack to avoid lock down. >> http://code.google.com/p/pharo/issues/detail?id=3086 >> >> >> >> Igor can you have a look and let me know: >> 1- if we should rollback Issue 3086: MCMethodDefinition>>shutdown hack to avoid lock down. >> 2- if we should integrate >> Issue 3048: MC method cache fix >> http://code.google.com/p/pharo/issues/detail?id=3048 >> >> I will integrate >> http://code.google.com/p/pharo/issues/detail?id=3091 >> > > Wait , MCMethodDefinition is only a consequence (however, removing it > from weakdependents would be good idea as well ;)). Yes I integrate it to avoid system hanging. > The real cultprit is HostSystemMenusProxy , which locks the weak > registry during finalization. > Then MCMethodDefinition>>shutdown simply locks at same point (trying > to obtain semaphore lock). > Note, that HostSystemMenusProxy locks finalization process, but not > the process which doing shutdown, > and then during image startup, a new finalization process get created. > That's why removing access to weakdependents in > MCMethodDefinition>>shutdown , kinda solved the issue. > In reality its not. > An old weak registry were sending #finalize outside a critical section: > > finalizeValues > "Some of our elements may have gone away. Look for those and activate > the associated executors." > | finiObjects | > finiObjects := nil. > "First collect the objects." > self protected:[ > valueDictionary allAssociationsDo:[:assoc| > assoc key isNil ifTrue:[ > finiObjects isNil > ifTrue:[finiObjects := OrderedCollection with: assoc value] > ifFalse:[finiObjects add: assoc value]] > ]. > finiObjects isNil ifFalse:[valueDictionary finalizeValues: > finiObjects asArray]. > ]. > "Then do the finalization" > finiObjects isNil ifTrue:[^self]. > finiObjects do:[:each| each finalize]. > > > So, there two ways to solve it: > a) perform finalization outside a critical section (see attached) > b) fix the HostSystemMenusProxy to prevent any manupulation with weak > registry during finalization. > > > I checked Squeak 4.2 image, and i can also say, that any attempt to > manipulate weak registry during finalization will also lock down a > finalization process (see Squeak's WeakRegistry>>finalizeValues & > WeakKeyDictionary>>finalizeValues) > > So, if we going to assume, in future that it is error to modify weak > registry during finalization, then we should leave the code in > WeakRegistry as-is, and fix HostSystemMenusProxy instead. > If not, the we should make sure that #finalize should be sent outside > weak registry's critical section. > > And the last note: if VM supports new finalization, it will happen > outside a critical section (See the > bottom of WeakRegistry>>finalizeValues). So any manipulations with > registry during finalization can't cause lockdown. > > > P.S. forwarded to Squeak-dev, to make Squeakers aware of potential > danger , when manipulating weak registry during finalization. > > -- > Best regards, > Igor Stasenko AKA sig. > <WeakRegistry-finalizeValues.st>_______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

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