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[Pharo-project] [ANN] A Unifying Mechanism for the Implementation of Concurrency Abstractions

by Stefan Marr

Hi, beware the shameless plug: Our paper Identifying A Unifying Mechanism for the Implementation of Concurrency Abstractions on Multi-Language Virtual Machines [1] introduces an ownership-based Meta-object Protocol (MOP) to enable the enforcement of the various concurrency semantics required by the different programming models discussed in literature. The prototypical implementation is done on top of Pharo 1.3 and available at SqueakSource3 [2] under the MIT license. You might be interested in it to experiment with new concurrent programming models. Typically, green threads are enough to be exposed to race conditions and other correctness problems. Thus, a CogVM is sufficient for experiments. RoarVM support is coming later, enabling experiments with the parallel aspects of these programming models as well. For the evaluation, we implemented a couple of concurrency models on top of it. Most notably, you can use Clojure-like agents, AmbientTalk-like actors, a basic CSP, Active Objects, and an STM that is a port of Lukas Renggli's work. These concurrency models work out of the box with the Metacello configuration given below (to the degree they were tested and benchmarked). You might also be interested in the AmbientTalkST implementation that was done as comparison as well as the direct port of Lukas' STM to Pharo 1.3 [3]. Please see the paper [1] for an introduction to the MOP and an example how to use it to make objects immutable and implement Clojure's agents guaranteeing all required semantics. The paper's abstract: Supporting all known abstractions for concurrent and parallel programming in a virtual machines (VM) is a futile undertaking, but it is required to give programmers appropriate tools and performance. Instead of supporting all abstractions directly, VMs need a unifying mechanism similar to INVOKEDYNAMIC for JVMs. Our survey of parallel and concurrent programming concepts identifies concurrency abstractions as the ones benefiting most from support in a VM. Currently, their semantics is often weakened, reducing their engineering benefits. They require a mechanism to define flexible language guarantees. Based on this survey, we define an ownership-based meta-object protocol as candidate for VM support. We demonstrate its expressiveness by implementing actor semantics, software transactional memory, agents, CSP, and active objects. While the performance of our prototype confirms the need for VM support, it also shows that the chosen mechanism is appropriate to express a wide range of concurrency abstractions in a unified way. The code can be loaded into a fresh Pharo 1.3 image [4] with the following Gofer expression. However, be aware this is experimental software. Furthermore, note that you will need to acknowledge changes to the Process class: Gofer new url: 'http://ss3.gemstone.com/ss/Omni'; package: 'ConfigurationOfOmni'; load. (Smalltalk at: #ConfigurationOfOmni) loadTOOLS2012. As mentioned before, the paper gives some examples. The definition of different concurrency semantics can be found in subclasses of OstDomain. Examples of how to use any of the existing concurrency models are either the unit tests, or the included benchmarks. Note that the MOP based implementation of AmbientTalkST does use the same class names. Thus, to use the ad-hoc implementation, you will need to load it into a different image: Gofer new url: 'http://ss3.gemstone.com/ss/Omni'; package: 'ConfigurationOfAmbientTalkST'; load. (Smalltalk at: #ConfigurationOfAmbientTalkST) loadTOOLS2012. Similarly, the port of Lukas Renggli's STM to Pharo needs to be loaded into a separate image, too. This version is not using our MOP: Gofer new url: 'http://ss3.gemstone.com/ss/LRSTM'; package: 'ConfigurationOfLRSTM'; load. (Smalltalk at: #ConfigurationOfLRSTM) loadTOOLS2012. Acknowledgements: Thanks to Lukas for his STM implementation I used here. It was also a strong inspiration for my bytecode transformation approach. Best regards Stefan -- Stefan Marr Software Languages Lab Vrije Universiteit Brussel Pleinlaan 2 / B-1050 Brussels / Belgium http://soft.vub.ac.be/~smarr Phone: +32 2 629 2974 Fax: +32 2 629 3525

March 9, 2012

Re: [Pharo-project] more Nautilus feed back

by Fabrizio Perin

Hi, I just started to play with nautilus so this is just a quick feedback: - Are the icons on the packages really useful? I think they just overload the list with redundant information which is not really useful. Can they be simply removed? - When I tried to run a test class (ZnClientTests just to try it out) with several tests inside a big stack of bluish transparent boxes started to flood the left side of the image. Moreover for every failing assertion I get a debugger open. Which is the idea behind this? First I cannot do TDD. Can we have just one debugger window open at the time (for instance with the first failing assertion)? Second the image is polluted with elements which confuse me. Can we have just one bluish box with the whole results report? Third, the rendering of all this elements is very slow. I will play a bit more with it and I will give you more feedback. Regards, Fabrizio 2012/3/9 Benjamin <benjamin.vanryseghem.pharo(a)gmail.com> > Interesting proposition, I will keep that on my desktop :) > > Thanks > Ben > > On Mar 9, 2012, at 12:27 PM, Helene Bilbo wrote: > > > > > Igor Stasenko wrote > >> > >> so then go finish arts and design schools (min 5 years each). and only > >> then you may get back and continue working on nautilus! Hurry up. :) > >> > >> I can also easily tell what i don't like in Nautilus. Much harder is > >> to propose alternative. > >> > > So after finishing art school i propose a better UI in the attached > drawing. > > It gets rid of all Toggle-Buttons except one for the comments: > > > > http://forum.world.st/file/n4459175/nautilusui.jpg > > > > Good Luck with the exams, Helene. > > > > > > -- > > View this message in context: > http://forum.world.st/more-Nautilus-feed-back-tp4457416p4459175.html > > Sent from the Pharo Smalltalk mailing list archive at Nabble.com. > > > > >

March 9, 2012

Re: [Pharo-project] GSoC proposal: Naked Objects using Magritte

by StÃ©phane Ducasse

would be cool too :) On Mar 9, 2012, at 2:43 PM, Stephan Eggermont wrote: > After a discussion with Esteban, Nick challenged me to submit a proposal. > An alternative would be to start from Glamour instead of from Magritte 3. > > > Proposal: Extend Magritte 3 to create Naked Objects style interfaces > Level: Intermediate > Possible mentor: Stephan Eggermont > Possible second mentor: Esteban Lorenzano > > Description > > "What if you never had to write a user interface again? What if you could > simply expose your business objects directly to the end user? How would this > affect your productivity? The way you work? The flexibility of your > applications? Is this even possible? Sometimes, yes. This describes a > style of application development, Naked Objects, where you write just the > business objects, and a framework lets your users interact directly with > these objects." (Dave Thomas) > > Technical Details > > Using Magritte we can already build (web/glamour)components representing > attributes of domain objects. What should we add to enable a NO UI? > - (better descriptions of) relationships between domain objects; > - descriptions of actions, with and without parameters; > - build a canvas where multiple domain objects can be shown; > - make the domain objects identifiable with an icon and title; > - add drag-and drop to initiate actions and manage relationships; > - add buttons/drop down menus for actions; > (and a few other things, of which I'll think when these are finished :) > > Benefits to the student > > Learn to use and extend a high quality framework. > Learn and practice interaction design. > Learn about hexagonal architecture. > > Benefits to the community > > The Naked Objects UI enables a very short feedback loop when prototyping a > domain model. It provides a showcase for the superiority of smalltalk as a > rapid development environment. It allows scaling down the engineering effort > needed to create custom solutions. It fits very well with exploratory modeling. > In a mixed UI style it allows focusing effort on only the critical parts of the UI. > >

March 9, 2012

Re: [Pharo-project] Increase populatity of Pharo by doing some Killer-OpenSource-Tools

by StÃ©phane Ducasse

On Mar 9, 2012, at 1:05 PM, Stefan Krecher wrote: > Hi, > > i suspect, that the popularity of Pharo (or Smalltalk in general) > could be increased by developing some "Killer-OpenSource-Tools". > By "Killer-OpenSource-Tools" i think of Tools, e.g. for supporting the > Software-Development-Process in general. Moose of course could become > such a tool. > But i think of some standard Tools like Bug-Tracking/ Project Management. I agree > Let me explain by a short example. > In a lot of projects i needed to use Trac (http://trac.edgewall.org/) > as a Ticketing system. Trac is a "simple" Python script to manage > Tasks/ Tickets, it is customizable and can be enhanced. But it is very > very ugly, configuration is very unhandy. We like to print tickets to > pin them to a whiteboard for use in daily scrum meetings. This and > additional reports are made by BIRT-Reports. Everything feels very > unstable but a lot of companies prefer Trac because of licensing > issues (e.g. Jira is better but commercial). > A simple and good looking Ticketing-System for use in an agile team > would be a good thing - it's a CRUD-Application with some Reporting > and maybe some eye candy. Why don't you start based on experience to build a tool and share with us. > Another idea could be a Tool for organizing activities regarding > Softwaretests, e.g. generation of Testspecifications/ -plans and > reports on test-runs. I used TestLink (http://www.teamst.org/) but it > is ugly and unhandy too ... > > Pier CMS could be a good solution for Intranets or Websites, but the > lack of Documentation keeps people from using it. > > Is anyone interested in creating some OpenSource-Projects for use in a > wider range? Those Tools should look "sexy" and should be easy to try > (OneClick) or to install as a Service. Yes we are lot of people interested in that. Just quite busy. > > regards, > Stefan >

March 9, 2012

Re: [Pharo-project] GSoC proposal: Naked Objects using Magritte

by Tudor Girba

I could offer help here as well. Cheers, Doru On Fri, Mar 9, 2012 at 2:43 PM, Stephan Eggermont <stephan(a)stack.nl> wrote: > After a discussion with Esteban, Nick challenged me to submit a proposal. > An alternative would be to start from Glamour instead of from Magritte 3. > > > Proposal: Extend Magritte 3 to create Naked Objects style interfaces > Level: Intermediate > Possible mentor: Stephan Eggermont > Possible second mentor: Esteban Lorenzano > > Description > > "What if you never had to write a user interface again? What if you could > simply expose your business objects directly to the end user? How would this > affect your productivity? The way you work? The flexibility of your > applications? Is this even possible? Sometimes, yes. This describes a > style of application development, Naked Objects, where you write just the > business objects, and a framework lets your users interact directly with > these objects." (Dave Thomas) > > Technical Details > > Using Magritte we can already build (web/glamour)components representing > attributes of domain objects. What should we add to enable a NO UI? > - (better descriptions of) relationships between domain objects; > - descriptions of actions, with and without parameters; > - build a canvas where multiple domain objects can be shown; > - make the domain objects identifiable with an icon and title; > - add drag-and drop to initiate actions and manage relationships; > - add buttons/drop down menus for actions; > (and a few other things, of which I'll think when these are finished :) > > Benefits to the student > > Learn to use and extend a high quality framework. > Learn and practice interaction design. > Learn about hexagonal architecture. > > Benefits to the community > > The Naked Objects UI enables a very short feedback loop when prototyping a > domain model. It provides a showcase for the superiority of smalltalk as a > rapid development environment. It allows scaling down the engineering effort > needed to create custom solutions. It fits very well with exploratory modeling. > In a mixed UI style it allows focusing effort on only the critical parts of the UI. > > -- www.tudorgirba.com "Every thing has its own flow"

March 9, 2012

[Pharo-project] GsoC - Nautilus Hazelnut

by Benjamin

Project name : Nautilus Level (Beginner, Intermediate, Advanced) : Intermediate Possible Mentor : Stephane Ducasse ? Description : Nautilus is a new browser based on the latests system meta model tools like RPackage or Ring. The goal is to ensure this browser has the stability and all the features required to become the next standard browser. Technical Details : Nautilus may be improved on different levels: fixing last bugs, improve the way the UI widget are defined to be able to easily change the UI representation, create some plugins for metrics, better traits integration, better icons. Morphic may have to be improved Benefits to the Student : The student will learn and use the latests infrastructure tools, the different Morphic's layers. He will also participate to a tool which is used and will be. Benefits to the Community : The community will gain a more stable and up to date default browser. Project name : Hazelnut Level (Beginner, Intermediate, Advanced) : Advanced Possible Mentor : Stephane Ducasse ? Description : Hazelnut is part of the Seed project which goal is to bootstrap the system. Technical Details : Ensure the validity of the created kernel and also improved the serialization mechanism. The goal is to clarify and ensure a creation mechanism which can be applied to a dynamically generated kernel or to a statically describe kernel as well. Benefits to the Student : Deep understanding of the system layouts, of the kernel definition, of the meta model and the reflexivity of the system. The student will also learn the object format and the basic of the VM use. Benefits to the Community : The community will gain a way to bootstrap a new fresh kernel from an existing image or from a kernel description. It could also be used to generate minimal kernel used for embedded technology. Ben

March 9, 2012

[Pharo-project] GSoC proposal: Naked Objects using Magritte

by Stephan Eggermont

After a discussion with Esteban, Nick challenged me to submit a proposal. An alternative would be to start from Glamour instead of from Magritte 3. Proposal: Extend Magritte 3 to create Naked Objects style interfaces Level: Intermediate Possible mentor: Stephan Eggermont Possible second mentor: Esteban Lorenzano Description "What if you never had to write a user interface again? What if you could simply expose your business objects directly to the end user? How would this affect your productivity? The way you work? The flexibility of your applications? Is this even possible? Sometimes, yes. This describes a style of application development, Naked Objects, where you write just the business objects, and a framework lets your users interact directly with these objects." (Dave Thomas) Technical Details Using Magritte we can already build (web/glamour)components representing attributes of domain objects. What should we add to enable a NO UI? - (better descriptions of) relationships between domain objects; - descriptions of actions, with and without parameters; - build a canvas where multiple domain objects can be shown; - make the domain objects identifiable with an icon and title; - add drag-and drop to initiate actions and manage relationships; - add buttons/drop down menus for actions; (and a few other things, of which I'll think when these are finished :) Benefits to the student Learn to use and extend a high quality framework. Learn and practice interaction design. Learn about hexagonal architecture. Benefits to the community The Naked Objects UI enables a very short feedback loop when prototyping a domain model. It provides a showcase for the superiority of smalltalk as a rapid development environment. It allows scaling down the engineering effort needed to create custom solutions. It fits very well with exploratory modeling. In a mixed UI style it allows focusing effort on only the critical parts of the UI.

March 9, 2012

Re: [Pharo-project] more Nautilus feed back

by Benjamin

Interesting proposition, I will keep that on my desktop :) Thanks Ben On Mar 9, 2012, at 12:27 PM, Helene Bilbo wrote: > > Igor Stasenko wrote >> >> so then go finish arts and design schools (min 5 years each). and only >> then you may get back and continue working on nautilus! Hurry up. :) >> >> I can also easily tell what i don't like in Nautilus. Much harder is >> to propose alternative. >> > So after finishing art school i propose a better UI in the attached drawing. > It gets rid of all Toggle-Buttons except one for the comments: > > http://forum.world.st/file/n4459175/nautilusui.jpg > > Good Luck with the exams, Helene. > > > -- > View this message in context: http://forum.world.st/more-Nautilus-feed-back-tp4457416p4459175.html > Sent from the Pharo Smalltalk mailing list archive at Nabble.com. >

March 9, 2012

[Pharo-project] new CI Job: Project Pharo Kernel Reload Tests-Unix

by Pavel Krivanek

Hi, I created a new Jenkins job named "Project Pharo Kernel Reload Tests-Unix". It is the same job as Pharo 1.4 Tests-Unix but with Pharo Kernel Reload as the base. In ideal case it should have the same set of failing tests as Pharo 1.4 Tests-Unix (zero would be nice ;-)). Currently it has one more failing job: Tests.Release.ReleaseTest.testUndeclared. But I think it is a big achievement in itself :-) Cheers, -- Pavel

March 9, 2012

[Pharo-project] Increase populatity of Pharo by doing some Killer-OpenSource-Tools

by Stefan Krecher

Hi, i suspect, that the popularity of Pharo (or Smalltalk in general) could be increased by developing some "Killer-OpenSource-Tools". By "Killer-OpenSource-Tools" i think of Tools, e.g. for supporting the Software-Development-Process in general. Moose of course could become such a tool. But i think of some standard Tools like Bug-Tracking/ Project Management. Let me explain by a short example. In a lot of projects i needed to use Trac (http://trac.edgewall.org/) as a Ticketing system. Trac is a "simple" Python script to manage Tasks/ Tickets, it is customizable and can be enhanced. But it is very very ugly, configuration is very unhandy. We like to print tickets to pin them to a whiteboard for use in daily scrum meetings. This and additional reports are made by BIRT-Reports. Everything feels very unstable but a lot of companies prefer Trac because of licensing issues (e.g. Jira is better but commercial). A simple and good looking Ticketing-System for use in an agile team would be a good thing - it's a CRUD-Application with some Reporting and maybe some eyecandy. Another idea could be a Tool for organizing activities regarding Softwaretests, e.g. generation of Testspecifications/ -plans and reports on test-runs. I used TestLink (http://www.teamst.org/) but it is ugly and unhandy too ... Pier CMS could be a good solution for Intranets or Websites, but the lack of Documentation keeps people from using it. Is anyone interested in creating some OpenSource-Projects for use in a wider range? Those Tools should look "sexy" and should be easy to try (OneClick) or to install as a Service. regards, Stefan

March 9, 2012