Squeak-dev October 2006

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175 participants
305 discussions

3.9 Traits behavior code
by tim Rowledge 25 Oct '06

25 Oct '06

It looks a bit odd - given the aim of traits, insofar as I understand them - to have for example 4 identical methods #compile:classified:notifying:trailer: ifFail: in classes Behavior, TCompilingBehavior, TPureBehavior and TraitBehavior. Are they all really needed or are they perhaps left overs needing cleaning up? tim -- tim Rowledge; tim(a)rowledge.org; http://www.rowledge.org/tim Performance is easier to add than clarity.

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headless swiki for Mac OS X? -nodisplay and -headless not available?
by Daniel Green 25 Oct '06

25 Oct '06

I'm trying to get a swiki running on my mac such that it starts at boot time and doesn't depend on me starting the Mac OS X Squeak app wrapper manually upon desktop login. Is that possible and if so, has somebody documented it? It looks like it should be possible to fire off "squeak -headless" or "squeak -display" in a system startup script but I only find Linux and Solaris versions for server-only mode. The 3.8.latest version of Squeak for Mac OS X doesn't seem to like either option. Thanks in advance for any insights or pointers to documentation. Best regards, -- DanG Daniel Green, Sun Microsystems Parkville, Missouri http://parkville.servebbs.org/media/

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Removing Etoys (was Re: A process proposal for 3.10)
by Robert Hawley 25 Oct '06

25 Oct '06

On Oct 24, 2006, at 9:46 PM, karl wrote: > Stéphane Rollandin skrev: >> goran at krampe.se wrote: >>> >>> PS. How many Squeakers on squeak-dev use eToys in official >>> Squeak, hands >>> up? >> >> >> I do >> >> Stef >> >> > I do. > Karl > Count me in. Markus I use it too Yours Bob

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[Q] Reading tar.gz archives from inside Squeak
by Edgar J. De Cleene 24 Oct '06

24 Oct '06

Doing some google , I found this from Ned and from a long time ago... > I've made space (in Archive) for other kinds of archives. It'll take a bit of > refactoring. My plan was to add Tar archives at some point. That should be > easy. Unfortunately, support for .tar.gz (compressed Tar) archives would > require multiple passes through the decompression to be able to extract > individual files -- one pass to get the members built, then for each member, > a scan through all the compressed data to the member start. Compressed tar > files are so ugly compared to zip files... > > The problem with .gz files is that they're a degenerate form of archive: they > can only hold one file! So the viewer would have to enquire of the archive > whether adding was possible. I wish know if some Squeaker have a newer code or examples. Now what I see how nice SkinsII is and use the themes what Todd suggest, I wish have a collection of themes , inside Squeak. Any lead or clues was appreciated. Edgar __________________________________________________ Correo Yahoo! Espacio para todos tus mensajes, antivirus y antispam �gratis! �Abr� tu cuenta ya! - http://correo.yahoo.com.ar

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[ANN] Etoys in OLPC build
by Bert Freudenberg 24 Oct '06

24 Oct '06

Starting with today's build #122, Etoys is included in the OLPC software distribution: http://olpc.download.redhat.com/olpc/streams/development/build122/ jffs2/build.log This means it will come pre-installed on the first actual laptops (a.k.a. "B-test") manufactured next month. Thanks to all who made this possible, and please keep contributing! There still is a lot of work to do over the next months. - Bert -

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Re: Efficient thread-local shared variables
by Klaus D. Witzel 24 Oct '06

24 Oct '06

Hi Reinout, on Tue, 24 Oct 2006 18:44:49 +0200, you wrote: > Klaus wrote: >> >> I don't know why but the discussion with you "inspired" three new >> operations for my implementation: >> >> - specialization, clones the anonymous class (shares the method >> dictionary) >> - proliferation of name space, locally copies the method dictionary >> ("rapidly" doubles it, still shares methods, variables and state) > > I presume you want to do above at Process creation time, and Yes, e.g. at "schema creation" time. >> - proliferation of state, locally clones "un-shares" a variable (and so >> its state) > > on global var assignment. Yes, e.g. at "schema evolution" time. > > Another approach could be to (ab)use SearchOrder. Assuming you still > have something like a 'global or 'default' scope you can put that at the > bottom of your SearchOrder and have a per-thread Vocabulary (perhaps > with scoping support) at the top of the SearchOrder. > > So at process creation time you only need to create an *empty* > Vocabulary for each scope and chain it to the global SearchOrder, > reading a global var will now fall through to the global definitions > while assigning a new value to that var will put it in the topmost > Vocabulary masking the global state of that variable. :) > Thinking this through even further: you could defer the creation of the > thread-local Vocabularies in the SearchOrder until the first write is > done, if the code only does reads the Process creation overhead can be > pretty close to zero :-) > Thank you for sharing the ideas! /Klaus > > R > - >

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Re: Efficient thread-local shared variables
by ncellier＠ifrance.com 24 Oct '06

24 Oct '06

Yes, despite very confusing names i used, you understood me well, "key" was to be replaced with any variable name lying in the pool dictionary. Thank you for these explanations. I understand that having mutable literals would break VW JIT. It may be worse if we use a trick to share a literal reference between two methods (the getter and setter), and that trick is not recognized at JIT level... In order to use traditional compiler optimizations, you could maybe use a class var for each pool dictionary entry in your anonymous class instead of a literal reference. This way, no use to flush the VM cache whenever the value changes... Compared to traditional global variable access that directly adresses the association (with value or value:), this cost a first method call to get the thread-dependent pool dictionary and an additional method lookup to get/set the value. Could such kind of method lookup be reduced by an inlining cache a la strongtalk ? Nicolas Le Mardi 24 Octobre 2006 16:17, vous avez écrit : > On Oct 24, 2006, at 12:18 PM, ncellier(a)ifrance.com wrote: > > So you have to share the first literal between read and write > > access methods ? > > like pseudo byte code: > > key > > ^(literalAt: 1) value > > > > key: aValue > > ^(literalAt: 1) value: aValue > > Your code confuses me, but you seem to be talking about implementing > Association behavior. In my scheme CompiledMethods come closest to > this role. > > So getting to the 'association' could be implemented on the anonymous > class as > > associationAt: aSymbol > ^self compiledMethodAt: aSymbol > > then CompiledMethod could implement > > key > ^self selector > > value > ^self localAt: 1 > > > Changing the value is something I haven't needed/tried yet because in > VW matters are complicated by the JIT cache that would (might?) need > to be flushed. This requires me getting to the class that holds this > CompiledMethod. Conceptually: > > value: anObject > self localAt: 1 put: anObject. > self classThatImplementsMe flushVMMethodCashesFor: self selector. > > > Overall I'm not too keen on modeling full dictionary behavior because > my 'dictionary' is already different in that it is reified as two > objects (the anonymous class and its singleton instance), the class > can be regarded as a mirror-like accessor to the dictionary for doing > 'meta' queries like getting to an 'association' and for altering the > dictionary contents. The singleton instance is used for lookup only > (any support methods implemented on it would clash with keys you > might want to use, currently only #doesNotUnderstand: is implemented > on my anon class). > > > > > One of my pet peeves about St is that #doesNotUnderstand: should be > implemented on he class side so it doesn't pollute the object's > selector namespace... > > R > - ________________________________________________________________________ iFRANCE, exprimez-vous ! http://web.ifrance.com

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Efficient thread-local shared variables
by Andreas Raab 24 Oct '06

24 Oct '06

Folks - For a variety of reasons I am in dire need of the ability to vector shared variables (globals, class vars and pool vars) through an extra indirection vector per process (really per island but binding per process seems to be simpler for now). Since I need this for *each and every shared variable* it needs to be *very* efficient. The question is: What is the most efficient way to implement such a scheme? There are a couple of ways I can think about: 1) Just use a dictionary. The main disadvantage is the lookup cost which could be handled by making it a special kind of dictionary and implementing the lookup in a primitive. This is a good fallback position but probably just a little slow in general. It could implemented by something along the lines of: ProtoObject>>lookup: sharedBinding "Look up the value of the given shared binding in the currently executing process." ^Processor activeProcess scope at: sharedBinding ifAbsent:[nil]. which is pretty straightforward. 2) Use message lookup, e.g., send a message. This is simple to describe but not necessarily simple to implement correctly. Here is how the simulation would look like: ProtoObject>>lookup: sharedBinding "Look up the value of the given shared binding in the currently executing process." ^[Processor activeProcess scope perform: sharedBinding key] on: MessageNotUnderstood do:[:ex| ex return: nil]. One problem here is that the key needs to be unique within all possible keys which is a problem if there is a name conflict. This can be resolved by implicitly prefixing names with the place where they are defined so it's not such big of a deal conceptually but practically the impact of that change might be more visible. The other problem is that the scope object needs to hold all the objects which means quite a number of them. OTOH, one could argue that in many ways "Smalltalk" is just an object with a few thousand iVars so having a class representing the namespace defined by Smalltalk may be quite reasonable. 3) Use "some" integer index caching scheme. The main idea here is in realizing that really, option #2 doesn't quite work since classes can't have more than 256 iVars so we'd need to have an indirection through an array to be able to access these variables. If that is so, then why can't we inline the entire access pattern and have the scope just be an array that we index directly? This is actually the most interesting approach to me because (as far as I can tell) it would be by far the most efficient. The basic idea goes like this: If all shared variables are assigned a "global index" then only this index is required to use them. Any use of the shared variable Foo would be inlined to "Processor activeProcess scope at: FooIndex" which (given proper primitive support) would probably be by far the fastest version (if offered a byte code it should rival the current speed of accessing shared variables). [I'll admit that there are some tricky issues with this approach as well, like the size needed for the scope object and whether or not to use hash lookup instead of indexing] In any case, I'm trying to gather options. If any of you have any new ideas or have tried one or the other (successfully or not) or have any other comments to make I'd love to hear about it. Cheers, - Andreas

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Re: Efficient thread-local shared variables
by ncellier＠ifrance.com 24 Oct '06

24 Oct '06

So you have to share the first literal between read and write access methods ? like pseudo byte code: key ^(literalAt: 1) value key: aValue ^(literalAt: 1) value: aValue Le Mardi 24 Octobre 2006 10:02, Reinout Heeck a écrit : > > 2) Use message lookup, e.g., send a message. This is simple to > > describe but not necessarily simple to implement correctly. Here is > > how the simulation would look like: > > I have experimented with this in VisualWorks (to implement a new > namespace system, not per-process pools) with great results regarding > speed. The two concepts I needed (stolen from Forth) where Vocabulary > (a Dictionary) and SearchOrder (a stack of those dictionaries). My > breakthrough came when I realized that my search rules in a > SearchOrder where the same as those the VM uses when doing method > lookup. > > So I implemented a Vocabulary 'instance' as a pair of a anonymous > class and a singleton instance of that class, lookup is done by > sending a message to the instance (fast), insertion/removal is done > by adding/removing methods in the class (slow). > The methods are very simple: they return their first literal, where > the literal slot holds the value to be returned from the dictionary > for the key assigned as that method's selector. > > > ProtoObject>>lookup: sharedBinding > > "Look up the value of the given shared binding in the currently > > executing process." > > ^[Processor activeProcess scope perform: sharedBinding key] > > on: MessageNotUnderstood do:[:ex| ex return: nil]. > > In my scheme you can get rid of the cost of this exception handler by > reimplementing #doesNotUnderstand: on the anonymous class so it > raises a KeyNotFound error (or returns nil as your snippet suggests). > In VW #doesNotUnderstand: is fully supported by the VM optimizations > (ICs, PICs, hoisting etc..) making lookup misses a fast path, I don't > know whether Squeak does the same in the case of #doesNotUnderstand:, > you may want to measure that. > > ProtoObject>>lookup: sharedBinding > ^Processor activeScope perform: sharedBinding key > > > One problem here is that the key needs to be unique within all > > possible keys which is a problem if there is a name conflict. This > > can be resolved by implicitly prefixing names with the place where > > they are defined so it's not such big of a deal conceptually but > > practically the impact of that change might be more visible. > > This is where SearchOrder enters the picture (assuming your conflicts > arise because you don't model scoping). > SearchOrder is implemented by chaining Vocabularies through the > #superclass attribute of the anonymous class. The VM will run through > this chain when a miss happens on the first Vocabulary and the nice > thing is that it will probably optimize future lookup of this key (by > hoisting). > > Implementing scoping is obviously more involved since you need to > know /where from/ the lookup is performed. > > Naively: > ^(Procesor activeScopeFor: self class) perform: sharedBinding key > > Perhaps you can make gains by cashing the per-process SearchOrders > belonging only to this calling scope in the sharedBinding? > > ^(sharedBinding scopeFor: Processor activeProcess) perform: > sharedBinding key > "we lost the 'self class' because the binding already 'knows' that" > > That last snippet clearly wants to be implemented on sharedBinding > instead of ProtoObject ;-) > > > The other problem is that the scope object needs to hold all the > > objects which means quite a number of them. OTOH, one could argue > > that in many ways "Smalltalk" is just an object with a few thousand > > iVars so having a class representing the namespace defined by > > Smalltalk may be quite reasonable. > > In my scheme Smalltalk would be modeled by an anonymous class that > implements thousands of methods, each with one literal, no ivars are > involved. > So you are limited by the maximum number of methods a class may > implement. I guess that is infinite for our purposes, but if Squeak > does have an upper limit on the number of methods per class you can > work around that by splitting the oversized Vocabularies into > multiple Vocabularies that are placed adjacent in the SearchOrder. > > > > > > I don't actively follow this list, so please CC reinz(a)desk.org if you > have any questions. > > Furthermore I'm vain, so please credit me if you decide to run with > this :-) > > R > - ________________________________________________________________________ iFRANCE, exprimez-vous ! http://web.ifrance.com

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Re: Underscore in 3.9
by Klaus D. Witzel 24 Oct '06

24 Oct '06

Stef & Marcus, would it be possible to change all syntaxHighlightingAsYouType* Preferences to values that do not cause confusion for beginners. This was already done so for the Squeak-dev image. Thank you very much in advance! /Klaus On Tue, 24 Oct 2006 12:38:29 +0200, Ramiro Diaz Trepat wrote: > Thank you Klaus. > Everything is fine now. > Probably that defaullt setting should be changed before the release, > shouldn't it? > > > On 10/24/06, Klaus D. Witzel <klaus.witzel(a)cobss.com> wrote: >> Hi Ramiro, >> >> on Tue, 24 Oct 2006 00:30:23 +0200, you wrote: >> >> > Hello everyone, >> > I started using the latest 3.9 image and there are no := there :) >> > Only underscores. >> > Even when I write := it turns into _ when I save. >> > I am sure there is a very silly option out there to deactivate >> > this behaviour. Anyone can tell me? >> > Thanks >> >> Open Preference Browser and in the searchbox type >> syntaxHighlightingAsYouType. >> >> This will show up three underscore and := related preferences. >> >> Unfortuntely the initial preferences in the stock 3.9 image are as you >> desribed. >> >> Have a look at the developer's image, there this (and other preferences) >> are pre-set for meeting the expectations of developers, the image also >> comes with cool tools pre-loaded >> >> - http://damiencassou.seasidehosting.st/seaside/pier >> >> /Klaus >> >> _______________________________________________ >> Beginners mailing list >> Beginners(a)lists.squeakfoundation.org >> http://lists.squeakfoundation.org/mailman/listinfo/beginners >>

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