May 2023 - Pharo-dev - lists.pharo.org

[Pharo12] commentSourcePointer and Metaclass

by Marcus Denker

Hi, up to Pharo11, the commentSourcePointer that is used to read and write the class comments was in ClassOrganization. In Pharo 12, we moved the commentSourcePointer to Class, Metaclass therefore has no empty commentSourcePointer anymore via itâs organizer. PR is mergedâ¦ these are of course more steps then you would think Started in Pharo11: - ix-tests-commentSourcePointer #11441 https://github.com/pharo-project/pharo/pull/11441 - Add commentSourcePointer to ClassDescription #11326 https://github.com/pharo-project/pharo/pull/11326 Pharo 12: - Set-CommentSourcepointer-ClassDescription #13171 https://github.com/pharo-project/pharo/pull/13171 - remove commentSourcePointer from ClassOrganization #13176 https://github.com/pharo-project/pharo/pull/13176 - CommentSourcePointer-move-methods-down #13640 https://github.com/pharo-project/pharo/pull/13640 - move commentSourcePointer from ClassDescription to Class #13643 https://github.com/pharo-project/pharo/pull/13643 - fix BehaviorTest>>#testInstSize #13648 https://github.com/pharo-project/pharo/pull/13648 and DONE. Moving ivars around in these classes is of course not easy, it can only be done with creating a PR by editing the code directly and then can be bootstapped, but you could not do that from a running image. (this explains why the commentSourcePointer was in ClassOrganization to start with, when it was introduced, this was the only place to put without major hassle) - the code is now much simpler to understand (Metaclass forwards all methods related to comments to #instanceSide) - it saves (a little bit) of memory (Smalltalk globals allClasses size * 8) bytes - is just one step to move merge ClassOrganization with ClassDescription, which will be a bit more relevant in terms of memory Marcus

May 4, 2023

Re: [Pharo12] Simplify CompiledMethod trailer: just support fixed sourcePointers

by Marcus Denker

The last PR now changes the trailer size to 5. https://github.com/pharo-project/pharo/pull/13580 <https://github.com/pharo-project/pharo/pull/13580> This way .changes/sources size can be 512GB. The most important things is, though, that this validates that we can change the space easily, e.g use 64bit and store some ObjectID... The fixed trailer does have an impact on speed for bytecode interpretation (via the Context). e.g. when looking for senders of special selectors, it has to fall back to use InstructionStream scanFor:, as the selectors are not in the literals. [#+ senders] bench Pharo11 : "'3.891 per second'" Pharo12 : "'4.913 per second'" This is some 25% faster, due to not having to instantiate a CompiledMethodTrailer for #endPC. Marcus > On 28 Apr 2023, at 11:07, Marcus Denker <marcus.denker(a)inria.fr> wrote: > > Hi, > > We did (im Pharo12) a simplification of how method trailers are handled. Below is the class comment of the now Deprecated and empty > class CompiledMethodTrailer. > > The issue https://github.com/pharo-project/pharo/issues/13512 has a list of all the intermediate steps done. > > ========== > > CompiledMethodTrailer was removed in Pharo12 > > It was responsible for encoding and decoding various kinds of compiled method trailer data, but that had many downsides: > > â¢ variable length trailers forced often called methods like CompiledMethod>>#endPC to instantiate an instance > â¢ setting a sourcePointer that required a different length trailer (e.g embedding sources) needed to create a new compiled method and do a become > â¢ to avoid that, the compiler supported to use an existing trailer and delegated instance creation of CompiledMethod to it. > â¢ using 1 byte for the trailer kind lead to the need use Variable length encoding already for our ~40MB source file for some methods. > > > All in all, the CompiledMethodTrailer added a lot of complexity for nothing. > > What do we do now? > > â¢ use use a fixed-length trailer (see #trailerSize) > â¢ writing and reading that is not that complex (see #setSourcePointer, #sourcePointer:) > > Q: I used to hand a trailer to the compiler, what should I do now? > > The compiler now creates always CompiledMethods with a fixed, but empty trailer. Just use #sourcePointer to set it after. > > Q: I used to clear the trailer using #copyWithTrailerBytes:, what should I do now? > > There is now #cearSourcePointer. Just use #copy before if you want a copy. > > Q: I want to have a non-installed method, but with source code. > The compiler now sets a #source property (and setting a source pointer via #sourcePointer: removes it). > If you use the compiler, you need to do nothing special anymore! All methods come with source via the property by default. > > >

May 3, 2023

[Pharo12] Simpler sourcePointer encoding

by Marcus Denker

Hi, After simplifying the CompiledMethodTrailer, let's look at what is stored there. It is an integer that encodes 1) which file? .sources or .changes ? and 2) the position in the file. So for two files we need one bit. So we could just shift the position by one and then use the last bit, if it is 1, we are .changes. But if you look at the code... it looks strange. I think this is for compatibility, without a bootstrap, changes like these are hard to do. So this is the old code: fileIndexFromSourcePointer: anInteger "Return the index of the source file which contains the source chunk addressed by anInteger" ^ (anInteger bitAnd: 16r1000000) ~= 0 ifTrue: [ 1 "sources file" ] ifFalse: [ anInteger >= 16r1000000 ifTrue: [ 2 "changes file" ] ifFalse: [ 0 "compatibility with StandardSourceFileArray" ] ] filePositionFromSourcePointer: anInteger "Return the position of the source chunk addressed by anInteger" | hi lo | hi := anInteger // 33554432. lo := anInteger \\ 16777216. ^ ((anInteger bitAnd: 16777216) ~= 0 or: [ anInteger < 16777216 "compatibility with StandardSourceFileArray" ]) ifTrue: [ hi * 16777216 + lo "sources file" ] ifFalse: [ (hi - 1) * 16777216 + lo "changes file" ] sourcePointerFromFileIndex: index andPosition: position "Return a sourcePointer encoding the given file index and position" | hi lo | (index = 1 or: [index = 2]) ifFalse: [self error: 'invalid source file index']. position < 0 ifTrue: [self error: 'invalid source code pointer']. hi := position // 16r1000000 *2 + index. lo := position \\ 16r1000000. ^ hi * 16r1000000 + lo While this is the "just shift by one and use the last bit" version: fileIndexFromSourcePointer: anInteger "Return the index of the source file which contains the source chunk addressed by anInteger" "1 is sources file, 2 is changes file" ^ (anInteger bitAnd: 1) + 1 filePositionFromSourcePointer: anInteger "Return the position of the source chunk addressed by anInteger, just shift by one" ^ anInteger >> 1 sourcePointerFromFileIndex: index andPosition: position "Return a sourcePointer encoding the given file index and position" (index = 1 or: [index = 2]) ifFalse: [self error: 'invalid source file index']. position < 0 ifTrue: [self error: 'invalid source code pointer']. "we shift the position by one and set the last bit for .changes" ^ (position << 1) bitOr: index - 1 The PR https://github.com/pharo-project/pharo/pull/13583 was merged in Pharo12 last week. Marcus

May 2, 2023

ESUG Presentation deadline is 1st of JUNE!

by stephane ducasse

Hello people do not wait the last moment, it will help the organizers. ESUG 2023 Call for Presentations 28.8.2023 to 01.9.2023 Lyon France https://esug.github.io <https://esug.github.io/> https://esug.github.io/2023-Conference/conf2023.html Deadline for submission is 1 st of June! ESUG is the premium and fun conference around smalltalk technologies. You can support the ESUG conference in many different ways: - Sponsor the conference. New sponsoring packages are described at http://www.esug.org/supportesug/becomeasponsor/ - Submit a talk, a software or a paper to one of the events. See below. - Attend the conference. We'd like to beat the previous record of attendance (180 people at Koln 2019)! - Students can get free registration and hosting if they enroll into the the Student Volunteers program. See below. ## Developers Forum: International Smalltalk Developers Conference We are looking for YOUR experience on using Smalltalk. You will have 30 min for presentations and 45 min for hands-on tutorials. The list of topics for the normal talks and tutorials includes, but is not limited to the following: - XP practices, Development tools, Experience reports - Model driven development, Web development, Team management - Meta-Modeling, Security, New libraries & frameworks - Educational material, Embedded systems and robotics - SOA and Web services, Interaction with other programming languages - Teaching Pearls and Show us Your Business New this year!!! We added two types of sessions in addition to the regular talks and show us your projects sessions. Show your business 10 min session (Get prepared!!) Teaching pearls : we want some session on how to teach some design aspects. We want your tip and tricks to teach Smalltalk or OOP. We expect to have several 10 to 15 min sessions aggregated. ### How to submit? Make a Pull Request here https://github.com/ESUG/esug.github.io/tree/source/2023-Conference/talks [Or but only if you are not connected to the worldâ¦ send an email to stephane.ducasse(a)inria.fr <mailto:stephane.ducasse@inria.fr>] Title: [ESUG 2023] Please follow the template below the email will be automatically processed! Name: Email: Abstract: Bio: Esug-list mailing list -- esug-list(a)lists.esug.org <mailto:esug-list@lists.esug.org> To unsubscribe send an email to esug-list-leave(a)lists.esug.org <mailto:esug-list-leave@lists.esug.org>

May 1, 2023

ESUG 2023 student volunteer program!

by stephane ducasse

Please distribute to the community and more Call for Student Volunteers Student volunteers help keep the conference running smoothly; in return, they have free accommodations, while still having most of the time to enjoy the conference. Pay attention: the places are limited so do not wait till the last minute to apply. Conference details: Send an email to stephane.ducasse at inria.fr <http://inria.fr/> and Oleksandr Zaitsev <olk.zaytsev(a)gmail.com <mailto:olk.zaytsev@gmail.com>> with: Title: [ESUG 2023 Student] name, gender, university/school, country, email address short description of you and why you are interested in participating For which period is accommodation covered? Accommodation is covered from Sunday 27.8.2023 to 01.9.2023 (including nights from Sunday to Monday and from Thursday to Friday). Students will be hosted in student rooms. ESUG additionally covers for the lunches during the week and one dinner. Duties include handling registration as people arrive at the conference, filling coffee machines, collecting presentation slides for ESUG right after the presentation is given, being present at an information desk to answer questions, and generally being helpful. Student volunteering makes the conference better, takes a fairly small amount of time and doesn't significantly interfere with enjoying and learning from the conference. Please Note, this role requires discipline and constant attention to all attendees. Information about hotel Student Volunteer rooms are booked at (to be announced). If you are student volunteer, do not book yourself, we have arranged the booking already! _______________________________________________

May 1, 2023