January 2016 - Pharo-users - lists.pharo.org

Pharo and OpenMP
by Dimitris Chloupis Feb. 3, 2016

Feb. 3, 2016

First my apology for the very long post but I think this will interest a lot of people. I have seen that someone out there .... HELOOOOOOO.... has tried Pharo with OpenMP https://pharoweekly.wordpress.com/2015/07/17/pharo-and-openmp/ For those that dont know what the hell OpenMP is, it nothing more than a collection of C pragmas, not very diffirent to our pharo pragmas , that tell to a compiler how to make code parallel. By parallel I don't mean pharo threads which are not really code that executes at the same time but true hardware threads and taking advantage of multiple cores etc. A pharo holy grail. Parallel coding is a bitch, there a lot of logical problems to face when you have pieces of code executing at the same time and you have to be aware of how the hardware is doing it because if you dont it so easy to get code as slow as running it on a single thread. I have been watching youtube tutorials by one of the guys that made OpenMP and I have to say I am very impressed. And it got me wondering "why the hell not pharo". The nice thing about OpenMP is that it does not matter that pharo VM can do only 1 thread which is the main thread, you can do multiple threads at C side using OpenMP and then collapse them to one thread and send the result back to pharo. Also note OpenMP is engineered by Intel so its a very serious library and comes included with most modern compilers and that includes GCC. Visual Studio and Clang / LLVM On the other hand lately I am also researching shared memory, actually its shared memory that lead me to OpenMP. My idea is basically extending the live coding enviroment of pharo beyond pharo. Its sound a bit crazy but the way I see it from my very small knowledge of C and shared memory is that right now, pharo live coding evniroment is isolated from outside world. You can do live coding while inside pharo but the moment you go outside , say you call a C library , live coding goes out of the window. This why we need to have session management to manage resource of calling C libraries to make sure when we reload the image , the image does not freak out that the live state of the C libraries is gone. This is also why many people push things to the image side. And of course its much more fun to code in Pharo than C. Now bare with me because things are now getting really interesting.... what if we could have an image flle for C code ? The things is that I am interested into shared memory because I want a very fast IPC, shared memory is the faster. I want to communicate Pharo with Blender, that I have accomplished via sockets, I can call python code and python libraries from pharo. But sockets are expensive in large loops, they work great for simple communication and much faster than pipes when used locally but try a large loop and socket will lag. Shared memory on the other hand is super fast, it basically it gives a part of memory that is shared among process that means also different applications. Now how a C image file fits into all this you may ask. Its simple. The most popular way of shared memory is called "memory mapped file", what it does is that it takes a file and loads it to memory as it is... sound familiar ? ;) what however is also doing is that it allows you share that part of the memory with any other application/ process as long as it also tries to load the file mapped to memory the same way. So what that means that we can have a place in memory that is shared between C code, including C dlls, and Pharo code. That file can act as an image file because we take that shared memory at any time that has been modified either by pharo, C or whatever else has access to shared memmory and store it back to that file. This is functionality that memory mapped files provide called msync. We talk here about a C image that work at least on surface very similarly to Pharo image. Now where OpenMP fits in all this ? Since OpenMP is about code that eats processors like peanuts , yes we could call it from a DLL, but with my approach even if that code crashes we will be able to restore it back to its live state because of that image format. All we do is reopen the memory mapped file and restore from it the shared memory. So we end up with true parallel live C/Pharo code with live state that and of course live code that is shared between Pharo and pretty much anything that uses C or python or why not other languages. So far I know how to do all of the above, well at least I am learning it now. Now the real challenge, which I have no clue about, is to make a Pharo parser to C using OpenMP. My thinking is as following. Why code in C and OpenMP when you could take something like Slang, which is basically pharo code that compiles to C, use pharo code with some pharo pragmas corresponding to OpenMP pragmas that will allow you to compile Slang OpenMP to C OpenMP and then compile it to an executable or dll that uses the shared memory memory mapped file solution. Crazy ? realistic ? far fetched ? maybe ? good in theory back in practice? Open to your thoughts.

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Problem to open Pharo 50 on Windows
by Justine STIENNE Feb. 2, 2016

Feb. 2, 2016

Hi, I wanted to download the lastest version of Pharo 50 on this website: http://files.pharo.org/get-files/50/ After having downloaded the lastest version for Windows (pharo-win-latest.zip) and the image in Pharo.zip, I try to to open the image with Pharo.exe but nothing appears, and the application never opened. Has anyone already had this problem and could help me ? Thank you, Justine

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[Updated Pharo by Example] SUnit chapter ready for reviews....
by stepharo Jan. 31, 2016

Jan. 31, 2016

Hi all yet another chapter ready for reviews. Special tx to Werner. I took all your feedback into account for the previous chapters. Stef

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Some Spotter Questions
by Sven Van Caekenberghe Jan. 31, 2016

Jan. 31, 2016

Hi, I managed to add a spotter extension and preview, but I still have some questions. Is there some global top level overview documentation about writing Spotter extensions ? Is the only way to add a 'global/first' search extension by adding a method to class GTSpotter itself ? I don't see any other package do that (in a modular way), it feels a bit wrong compared to how modular the GT inspector is. Is there a way to reuse a GT inspector view as a preview ? I tried that but it did not work, but what I copied over was 99% identical. Can you have tabs (multiple pages) in the preview ? Is it possible to control on what tab an inspector opens when a matching item is clicked (like to maintain the same view as the preview) ? What are some best practices for the order, exact matches, fast searching, etc ... ? Is it possible to search in multiple ways (multiple properties), not just collection -> itemName -> GTFilterSubstring ? (Say I want to search all fields of an address object). Searching for Color by name, or by RGB and other representations would seem like a good tutorial example (for me). Thx, Sven

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mini Actor model in two classes and
by stepharo Jan. 30, 2016

Jan. 30, 2016

Hi Since long time I wanted to have fun building a mini actor model. So I did one and I attached the skeleton of a future chapter for FunWithPharo :) Now I will read about futures and the rest. may be there is a problem with the compiling behavior. (see thread learningObject) Stef

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Use cases for methods with optional parameters
by Damien Cassou Jan. 29, 2016

Jan. 29, 2016

Hi, I would like to study the impact of adding optional parameters to keyword methods in Pharo. The goal of optional parameters is to facilitate the implementation of methods where some parameters are optional. For example, Seaside has: WAComponent>>request: aRequestString label: aLabelString default: aDefaultString onAnswer: aBlock ... This method of 4 arguments has only 1 required argument (aRequestString) and 3 optional ones. In the current implementation, this results in 7 additional methods that only delegate directly or indirectly to the one above: - request: - request:default: - request:default:onAnswer: - request:label: - request:label:default: - request:label:onAnswer: - request:onAnswer: Before starting to implement anything, I need to know if it makes sense. If you want to help me, please send me all the use cases you have by giving me: - the library name (and URL if not in Catalog), or "pharo" if it's in Pharo - the class where this happens - the range of selectors that make sense For the example above, this would be: - Seaside - WAComponent - request:* Thank you very much -- Damien Cassou http://damiencassou.seasidehosting.st "Success is the ability to go from one failure to another without losing enthusiasm." --Winston Churchill

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Windows headless and service
by Robert Kuszinger Jan. 29, 2016

Jan. 29, 2016

Hello Everyone! I'd like to install a Seaside app in Pharo in Windows (Server 2008). I live on linux but now I must put it on Windows. Pharo --help pops up a window with only a fragment of options. Pharo --headless TheFilenameOf.image Won't do anything. I've checked the available books but they mostly talk about mac osx/Linux which is welcome, anyway... Does anyone have experience with pharo (service) on windows? My version is (from readme): *Pharo 4.0 This distribution was built December 07, 2015.* thanks Robert

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[ANN] First release of FFICHeaderExtractor
by Mariano Martinez Peck Jan. 29, 2016

Jan. 29, 2016

Dear all, I am happy to announce the first release of FFICHeaderExtractor project. You can find the project and the documentation here: https://github.com/marianopeck/FFICHeaderExtractor Any feedback is more than welcome. Best, -- Mariano http://marianopeck.wordpress.com

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Paris is here
by Serge Stinckwich Jan. 29, 2016

Jan. 29, 2016

Where is the channel for the sprint ? on Slack or IRC ? Regards, -- Serge Stinckwich UCBN & UMI UMMISCO 209 (IRD/UPMC) Every DSL ends up being Smalltalk http://www.doesnotunderstand.org/

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Smalltalkhub scheduled maintenance next monday (February, 1st)
by Christophe Demarey Jan. 29, 2016

Jan. 29, 2016

Hello, Smalltalk will be down next monday (february, 1st) from 12:30 to 13:30 (french local time). IT will add storage to the root partition. Regards, Christophe

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