October 2014 - Pharo-dev - lists.pharo.org

Ring
by Roberto Minelli Oct. 21, 2014

Oct. 21, 2014

Hi guys, I havenât been programming for the last few weeksâ¦ I just discovered that Ring is no longer part of the image. I am wondering if it has been replaced by a new model or it just disappeared. Cheers, Roberto

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Re: [Pharo-dev] [squeak-dev] Image Segment semantics and weakness
by Mariano Martinez Peck Oct. 21, 2014

Oct. 21, 2014

Just a quick note I would like to share.... For my PhD, I did investigate ImageSegment very very deeply: http://dl.acm.org/citation.cfm?id=2076323 http://www.slideshare.net/MarianoMartinezPeck/2010-smalltalkspeckobject-swa… I didn't want to write Fuel just because. I took quite a lot of time to understand how ImageSegment primitives worked. From that effort, I remember a few conclusions: 1) I found only few users of ImageSegment 2) The few users I found, were NOT using the real purpose of ImageSegment, that is, object swapping. It was used instead as an object serializer. For that, they use #writeForExportOn: which ended up using SmartRefStream for the rest of the objects. 3) I noticed I could achieve the same performance or even better with an OO serializer built at the language side, with all the benefits this means. Of course, having Cog helped here.... In the Fuel paper: http://rmod.lille.inria.fr/archives/papers/Dias12a-SPE-Fuel.pdf you can find some benchmark comparison agains IS. Also in my PhD: http://rmod.lille.inria.fr/archives/phd/PhD-2012-Martinez-Peck.pdf Cheers, On Mon, Oct 20, 2014 at 9:56 PM, <jvuletich(a)dc.uba.ar> wrote: > Hi Eliot, > > > Hi All, > > > > I want to check my understanding of reference semantics for image > > segments as I'm close to completing the Spur implementation. > Specifically > > the question is whether objects reachable only through weak pointers > > should > > be included in an image segment or not. > > > > Remember that an image segment is created from the transitive closure of > > an > > Array of root objects, the *segment roots*. i.e. we can think of an image > > segment as a set of objects created by tracing the object graph from the > > segment roots. > > > > The segment always includes the segment roots. Except for the roots, > > objects are excluded from the segment that are also reachable form the > > roots of the system (the *system roots*, effectively the root > environment, > > Smalltalk, and the stack of the current process). > > > > Consider a weak array in the transitive closure that is not reachable > from > > the system roots, and hence should be included in the segment. Objects > > referenced from that weak array may be in one of three categories > > > > - reachable from the system roots (and hence not to be included in the > > segment) > > - *not* reachable form the system roots, but reachable from the segment > > roots via strong pointers (and hence to be included in the segment) > > - *not* reachable form the system roots, *not* reachable from the segment > > roots via strong pointers > > > > Should this last category be included or excluded from the segment? I > > think that it makes no difference, and excluding them is only an > > optimization. The argument is as follows. Imagine that immediately > after > > loading the image segment there is a garbage collection. That garbage > > collection will collect all the objects in the last category as they are > > only reachable from the weak arrays in the segment. Hence we are free to > > follow weak references as if they are strong when we create the image > > segment, leaving it to subsequent events to reclaim those objects. > > > > An analogous argument accounts for objects reachable from ephemerons. Is > > my reasoning sound? > > -- > > best, > > Eliot > > > > > > I think you are right. But there is a risk of somehow, someone, gaining a > strong reference to the object after the image segment was created, > breaking our invariants when the segment is loaded again. > > An object might be (not reachable / strongly reachable / weakely > reachable) from system roots and / or segment roots. This gives us 9 > possibilities. > Six of them are easy (and I'll not go into them). The other three are > tricky: > > a- Not reachable from system roots. Weakely reachable from segment roots. > Do not include them. It is best to run a GC before building the image > segment, to get rid of them (run termination, etc). This is to avoid the > risk of the object gaining somehow a strong reference after the segment is > built, making the segment miss the weak ref to it. Doing this way would > also mean that any objects affected by termination would be consistent, > both in the image and in the segment. > > b- Weakely reachable from system roots. Weakely reachable from segment > roots. > Do not include them. If the object manages to survive by gaining a strong > ref from the system roots, the weak ref will be repaired on segment load > (Am I right on this?) If the original object was included in the segment, > then on segment load it would point to a duplicate object that is about to > be collected (and maybe terminated?) In any case, doing this way would also > mean that any objects affected by termination would be consistent, both in > the image and in the segment. > > c- Weakely reachable from system roots. Strongly reachable from segment > roots. > Do include them. It seems reasonable to run a GC and get rid of them after > unloading the segment, to avoid the risk of the object gaining somehow a > strong ref in the image, and being duplicated on segment load. But doing as > I say means that we would be loading into the image an object that was > already terminated, although in the state it had before running > termination. Not really sure if this is ok. There could be some risk of > objects in the segment being in some pre-termination state, with some > objects in the image being in some after-termination state. In any case, > this would suggest bad design... So perhaps it makes sense to throw an > exception in these cases? > > I hope this rant is of use. > > Cheers, > Juan Vuletich > > > > -- Mariano http://marianopeck.wordpress.com

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[pharo-project/pharo-core]
by GitHub Oct. 21, 2014

Oct. 21, 2014

Branch: refs/tags/40315 Home: https://github.com/pharo-project/pharo-core

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[pharo-project/pharo-core] cea480: 40315
by GitHub Oct. 21, 2014

Oct. 21, 2014

Branch: refs/heads/4.0 Home: https://github.com/pharo-project/pharo-core Commit: cea4804b8fefa6b0ae6239807b797fbc59f69bac https://github.com/pharo-project/pharo-core/commit/cea4804b8fefa6b0ae623980… Author: Jenkins Build Server <board(a)pharo-project.org> Date: 2014-10-21 (Tue, 21 Oct 2014) Changed paths: M Collections-Strings.package/Symbol.class/instance/accessing/precedence.st R Graphics-Tests.package/ColorTest.class/instance/testing/testPrintHtmlString.st A Graphics-Tests.package/ColorTest.class/instance/tests/testPrintHtmlString.st A Graphics-Tests.package/PointTest.class/instance/tests - testing/testNormalized.st A Graphics-Tests.package/PointTest.class/instance/tests - testing/testSideOf.st A Graphics-Tests.package/RectangleTest.class/instance/tests-accessing/testBottom.st A Graphics-Tests.package/RectangleTest.class/instance/tests-accessing/testLeft.st A Graphics-Tests.package/RectangleTest.class/instance/tests-accessing/testRight.st A Graphics-Tests.package/RectangleTest.class/instance/tests-accessing/testTop.st M Graphics-Tests.package/RectangleTest.class/instance/tests/testInsettingByRectangleShouldNotProduceNegativeRectangle.st M Graphics-Tests.package/RectangleTest.class/instance/tests/testRectangleWithNegativeExtentShouldHaveZeroExtent.st A Graphics-Tests.package/RectangleTest.class/instance/tests/testRotateBy.st A Graphics-Tests.package/RectangleTest.class/instance/tests/testScaleBy.st A Graphics-Tests.package/RectangleTest.class/instance/tests/testTranslateBy.st M Refactoring-Critics.package/RBAllAnyNoneSatisfyRule.class/instance/accessing/name.st M Refactoring-Critics.package/RBCodeCruftLeftInMethodsRule.class/instance/initialization/initialize.st A ScriptLoader40.package/ScriptLoader.class/instance/pharo - scripts/script315.st A ScriptLoader40.package/ScriptLoader.class/instance/pharo - updates/update40315.st M ScriptLoader40.package/ScriptLoader.class/instance/public/commentForCurrentUpdate.st Log Message: ----------- 40315 14272 #_foo: isBinary ---> true https://pharo.fogbugz.com/f/cases/14272 14221 Tests around Graphics https://pharo.fogbugz.com/f/cases/14221 14271 RBCodeCruftLeftInMethodsRule>>initialize and RBAllAnyNoneSatisfyRule>>name have spelling errors https://pharo.fogbugz.com/f/cases/14271 http://files.pharo.org/image/40/40315.zip

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[pharo-project/pharo-core] 3e9067: 40314
by GitHub Oct. 21, 2014

Oct. 21, 2014

Branch: refs/heads/4.0 Home: https://github.com/pharo-project/pharo-core Commit: 3e906711b6a1c3b127beca11f7924cae7844e03a https://github.com/pharo-project/pharo-core/commit/3e906711b6a1c3b127beca11… Author: Jenkins Build Server <board(a)pharo-project.org> Date: 2014-10-21 (Tue, 21 Oct 2014) Changed paths: M Kernel.package/CompiledMethodTrailer.class/instance/accessing/setSourceBySelector.st M Kernel.package/CompiledMethodTrailer.class/instance/decoding/decodeNoTrailer.st M Kernel.package/CompiledMethodTrailer.class/instance/encoding/encodeNoTrailer.st M Kernel.package/CompiledMethodTrailer.class/instance/encoding/encodeSourceBySelector.st A Kernel.package/CompiledMethodTrailer.class/instance/initialization/clear.st A Kernel.package/CompiledMethodTrailer.class/instance/initialization/method_.st R Kernel.package/CompiledMethodTrailer.class/instance/initialize-release/clear.st R Kernel.package/CompiledMethodTrailer.class/instance/initialize-release/method_.st M KernelTests.package/CompiledMethodTrailerTest.class/instance/tests/testEncodingNoTrailer.st M Komitter.package/KomitterUI.class/class/specs/defaultSpec.st M NativeBoost-Core.package/NativeBoost.class/class/subscribing for session change/notifyAboutSessionChange_.st A ScriptLoader40.package/ScriptLoader.class/instance/pharo - scripts/script314.st A ScriptLoader40.package/ScriptLoader.class/instance/pharo - updates/update40314.st M ScriptLoader40.package/ScriptLoader.class/instance/public/commentForCurrentUpdate.st Log Message: ----------- 40314 14269 Komitter: Improve layout for long repo names https://pharo.fogbugz.com/f/cases/14269 14242 Installing a method is slow https://pharo.fogbugz.com/f/cases/14242 14257 Replace Announcer>>#on:send:to:s senders in NativeBoost-Core https://pharo.fogbugz.com/f/cases/14257 http://files.pharo.org/image/40/40314.zip

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[pharo-project/pharo-core]
by GitHub Oct. 21, 2014

Oct. 21, 2014

Branch: refs/tags/40314 Home: https://github.com/pharo-project/pharo-core

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[for testing] speeding up code loading
by Marcus Denker Oct. 21, 2014

Oct. 21, 2014

Hi, Â [Object compileSilently: 'foo ^ 1' classified: 'testing'] bench Â Â -- 267 per second Â Â Load from inbox: Â SLICE-Issue-14242-Installing-a-method-is-slow-MarcusDenker.3 Â Â run bench again ==> 2320 per second. Â Â This will work as long the .changes is small enough so that it uses a normal (not extended) source pointer. Â Â Â Marcus

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[ANN] New Gold Member LabWare
by Marcus Denker Oct. 20, 2014

Oct. 20, 2014

The Pharo Consortium is very happy to announce that LabWare has joined the Consortium as a Gold Industrial Member. About LabWare: "LabWare is recognized as the global leader in providing enterprise scale laboratory automation solutions. Our Enterprise Laboratory Platform combines the award-winning LabWare LIMSâ¢ and LabWare ELNâ¢, a comprehensive and fully integrated Electronic Laboratory Notebook application, which enables companies to optimize compliance, improve quality, increase productivity and reduce costs. LabWare is a full service provider offering software, professional implementation services and validation assistance, training, and world class technical support to ensure our customers get the maximum value from their LabWare products." - LabWare: http://www.labware.com - Pharo Consortium: http://consortium.pharo.org The goal of the Pharo Consortium is to allow companies to support the ongoing development and future of Pharo. Individuals can support Pharo via the Pharo Association: http://association.pharo.org

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Question on Package comments [SO]
by Nicolai Hess Oct. 20, 2014

Oct. 20, 2014

There was a question on SO about documentations for Packages: http://stackoverflow.com/questions/26292060/is-there-any-pharo-package-refe… I don't have enough reputation for adding comments in SO, therefore, I ask the questions here: The question is closed and I don't understand why. It is a valid question and I do remember that this was a topic on this list as well: show document/help text in configuration browser/ tooltip for packages in Nautilus/ comment package like it is done for classes. For that user, who asked the question on SO: At least for external packages there are sometimes some information on github or squeaksource and we should show him a link to the pharo user mailing list. (and no, the http://lmgtfy.com/ link is not helpful nor funny) nicolai

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Image Segment semantics and weakness
by Eliot Miranda Oct. 20, 2014

Oct. 20, 2014

Hi All, I want to check my understanding of reference semantics for image segments as I'm close to completing the Spur implementation. Specifically the question is whether objects reachable only through weak pointers should be included in an image segment or not. Remember that an image segment is created from the transitive closure of an Array of root objects, the *segment roots*. i.e. we can think of an image segment as a set of objects created by tracing the object graph from the segment roots. The segment always includes the segment roots. Except for the roots, objects are excluded from the segment that are also reachable form the roots of the system (the *system roots*, effectively the root environment, Smalltalk, and the stack of the current process). Consider a weak array in the transitive closure that is not reachable from the system roots, and hence should be included in the segment. Objects referenced from that weak array may be in one of three categories - reachable from the system roots (and hence not to be included in the segment) - *not* reachable form the system roots, but reachable from the segment roots via strong pointers (and hence to be included in the segment) - *not* reachable form the system roots, *not* reachable from the segment roots via strong pointers Should this last category be included or excluded from the segment? I think that it makes no difference, and excluding them is only an optimization. The argument is as follows. Imagine that immediately after loading the image segment there is a garbage collection. That garbage collection will collect all the objects in the last category as they are only reachable from the weak arrays in the segment. Hence we are free to follow weak references as if they are strong when we create the image segment, leaving it to subsequent events to reclaim those objects. An analogous argument accounts for objects reachable from ephemerons. Is my reasoning sound? -- best, Eliot

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