March 2010 - Pharo-dev - lists.pharo.org

[Pharo-project] A little quizzzzzzz : find the problem :)
by StÃ©phane Ducasse March 28, 2010

March 28, 2010

fileStream "Answer the file stream with position set at the beginning of my string. Answer a read only copy to avoid syntax errors when accessed via multiple processes." | theFile | (sourceFileNumber == nil or: [(SourceFiles at: sourceFileNumber) == nil]) ifTrue: [^ nil]. theFile := (SourceFiles at: sourceFileNumber) readOnlyCopy. theFile position: filePositionHi. ^ theFile string "Answer the receiver's string if remote files are enabled. Use a read only copy to avoid syntax errors when accessed via multiple processes." | theFile | (sourceFileNumber == nil or: [(SourceFiles at: sourceFileNumber) == nil]) ifTrue: [^'']. theFile := (SourceFiles at: sourceFileNumber) readOnlyCopy. ^[theFile position: filePositionHi. theFile nextChunk] ensure: [theFile close] text "Answer the receiver's string asText if remote files are enabled. Use a read only copy to avoid syntax errors when accessed via multiple processes." | theFile | (sourceFileNumber == nil or: [(SourceFiles at: sourceFileNumber) == nil]) ifTrue: [^ nil]. theFile := (SourceFiles at: sourceFileNumber) readOnlyCopy. ^[theFile position: filePositionHi. theFile position > theFile size ifTrue: [ self error: 'RemoteString past end of file' ]. theFile nextChunkText] ensure: [theFile close] I imagine a good soul could fix that and nicely published in the inbox :) Stef Did I say something negative about the past :)

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[Pharo-project] Help system question / monticello
by Michael Roberts March 28, 2010

March 28, 2010

Hi, based on Lukas' recent blog post about Monticello merging, I created some help system classes for this content. What is the best way to integrate this? We have our own version of Monticello in the Pharo repository. Which package, would we add it to? Or do we want to add it upstream somewhere? Also, has anyone thought or spiked some simple formatting? that would be really nice. thanks, Mike

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Re: [Pharo-project] [smalltalk-research] Re: [Esug-list] Google Summer Of Code 2010 news!!!
by Eliot Miranda March 28, 2010

March 28, 2010

On Sun, Mar 7, 2010 at 3:24 PM, Gilad Bracha <gbracha(a)gmail.com> wrote: > I'm all for it, and hope that John or Eliot can mentor. I would like to mentor something in this area, but I think the basic goal of a cross-platform system is not achievable in GSoC this summer. A specification of a non-blocking architecture and a reference implementation may be possible. Cross-platform is too big for a summer project and will require input from dialects and vendors. What affects my thinking is the following: 1. I designed and implemented the VisualWorks THAPI system, a threaded extension to the VisualWorks FFI. 2. I have a functional prototype of a multi-threaded FFI for the Cog VM based on David Simmons' VMs. 1's architecture is poor, being complex, slow and not very general (allows only FFI calls to be threaded). 2's architecture is rather simple, rather fast and very general (allows threading to be much more widely used, e.g. calls within plugins can be made threaded by surrounding them with two calls, disownVM and ownVM). 3. I have looked at marshalling semantics in the context of the VW FFI, Andreas' Squeak FFI & Alien, and am still of the opinion, one shared by David, - that the generation of marshalling stubs has to be lifted up into Smalltalk based on simple ABI compilers that somehow (e.g. through RTL) communicate down to a JIT that generates and caches marshalling code (i.e. that VM attempts to interpret simplified call specs, as happens in the VM and Squeak FFIs are in general doomed to poor performance and bugs) - that type coercion code also has to be lifted (e.g. character conversions on strings, null termination, type coercion) - that one be able to depend on a pinning garbage collector to deal with the issues of passing objects through the FFI (although there are workaround hacks that can serve temporarily) I don't see the point of spending a GSoC trying to implement an obsolete (unthreaded, lowest-common-denominator) cross-platform FFI; it won't get used. I do see benefit in an open-source reference implementation that provides some of the above (at least threading/non-blocking). If people agree that an open-source reference implementation is worth pursuing, then I will happily mentor. What the starting point is will depend on to what extent Cog has been open sourced (Teleplace may choose to open source single-threaded Cog initially, keeping back the threaded FFI for a while, it may not open source Cog at all; we'll see :) ). There are other starting points (current Squeak VMs, GST, Newspeak). But the outline above is a move towards better cross-platform commonality, not less, because it's an architecture in which the image does more (type coercion, compiling call signatures to RTL sequences) and the VM (except for the threading ;) ) does less. And so this direction does lead towards better cross-platform facilities. best Eliot

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[Pharo-project] [update 1.1] #11299
by StÃ©phane Ducasse March 27, 2010

March 27, 2010

11299 ----- - Issue 2222: Form dimmed - Issue 2209: Form conversion ligther/darker and other cool methods - Issue 2220: CombinedChar>>#add: - Issue 2217: fontFullName fixes - Issue 2219: redirect locations fix and tests - Issue 2221: primitiveFailed better feedback Stef

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[Pharo-project] Issue 2219: redirect locations fix
by stephane ducasse March 27, 2010

March 27, 2010

Hi network aware guy can you have a look at that? http://code.google.com/p/pharo/issues/detail?id=2219 I'm planning to integrate it in pharo but some incentive from you would help :) Stef

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[Pharo-project] Can I use GDB with SqueakVM ?
by Mariano Martinez Peck March 27, 2010

March 27, 2010

(cross posting) Hi folks. I have a SqueakVM with an image that uses SqueakDBX to talk to a database. SqueakDBX talks to a external library (written in C) called OpenDBX. At the same time, OpenDBX then talks to another library which is the database client library. When....I am having a problem with Firebird and it seems to be related with threads management. So, what I want to do is to start the SqueakVM with GDB, run my tests and try to get as much information as possible when it crash. So far I am in Ubuntu 9.10 and I have tried the following: ubuntu@ubuntu-desktop:~/opendbx/trunk/test$ gdb /home/ubuntu/squeak/pharo-vm-0.15.2f-linux/squeak GNU gdb (GDB) 7.0-ubuntu Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html > This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i486-linux-gnu". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /home/ubuntu/squeak/pharo-vm-0.15.2f-linux/squeak...done. (gdb) set args /home/ubuntu/squeak/pharo1.0-10500-rc1dev09.12.1/pharo1.0-10500-rc1dev09.12.dbx.1.image (gdb) run Starting program: /home/ubuntu/squeak/pharo-vm-0.15.2f-linux/squeak /home/ubuntu/squeak/pharo1.0-10500-rc1dev09.12.1/pharo1.0-10500-rc1dev09.12.dbx.1.image [Thread debugging using libthread_db enabled] Cannot find new threads: generic error (gdb) As you can see there the error "[Thread debugging using libthread_db enabled] Cannot find new threads: generic error" I am not an expert in C or VM so I don't know if I am doing the things correctly. I tried to google a bit, and I found different solutions. I copy exactly what I found: "I've find a workaround, i've link the debugging app with libpthread and now gdb feels happy, and i can run it with gdb !" "But however, if I compile the program with -pthread option, am able to debug the program: $ cc -W -Wall -Wextra -g 20.c `pkg-config --cflags --libs gtk+-2.0` -pthread" "The problem appears to be that something goes wrong with dynamically loading libpthread in case the program has not been linked to it at compile time. That would explain why it works when you use msethread, because that one explicitly links to libpthread at compile time (via the imports in mselibc, I guess). Why dynamically loading libpthread causes problems is another question. Maybe somehow the cthreads unit loads a different ("wrong") copy of libpthread than the one the static linker uses when linking the program. Or, alternatively, maybe the static linker selects a different version of libc to link against if libpthread is also used (libc and libpthread are quite interwoven on GNU systems, even though they are separate libraries)." So...I don't understand exactly how can I fix it. Thanks for any help. Mariano

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[Pharo-project] bug in Pharo RC3 , OB related
by Mariano Martinez Peck March 27, 2010

March 27, 2010

In PharoDev RC3 open a class browser and go to any class that overrides a method. For example, TestCase >> assert: Now, click on the green narrow to go to the super class implementor: MessageNotUnderstood: TestCase class>>withAllSuperAndSubclassesDo: The method withAllSuperAndSubclassesDo: is not in Pharo 1.0 but it is in 1.1 Cheers Mariano

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[Pharo-project] How to easily intercept messages sent to ALL objects ?
by Mariano Martinez Peck March 27, 2010

March 27, 2010

Hi folks. I want to intercept (and do something) for all objects. I know few approaches, for example: 1) using method wrappers (implementing run: aSelector with: arguments in: aReceiver) I can wrap all compiled methods of all classes and there I have the receiver. 2) become all objects to some kind of hacky object that stores the original object and that redefines the doesNotUnderstand: But in 1) I need to change all CompiledMehtod of all classes. in 2) I have to become all the objects to another object Then my question is, is there an easier way to intercept all messages send to all objects from the image side (not going to vm) and with a lower cost ? And if going to vm, how ? Thanks. Mariano

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[Pharo-project] [update 1.1] #11298
by Marcus Denker March 27, 2010

March 27, 2010

11298 ----- Issue 2216: remove 21 unsent methods Issue 2215: testFontFullName recursively deletes all files in the image directory - Undo a change from Issue 2030 Marcus -- Marcus Denker -- http://www.marcusdenker.de INRIA Lille -- Nord Europe. Team RMoD.

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[Pharo-project] Ubuntu users
by Schwab,Wilhelm K March 27, 2010

March 27, 2010

Hello all, I hope this is simply irresponsible FUD, but one possible explanation for my image meltdown yesterday is that it was fried in copying to a USB stick. I have also been messing around with FFI, which is another way things could have gone bad. Attempts to load the bad image end in "Read failed or premature end of image file." I am asking myself whether unmounting USB drives is working as well as it did prior to some updates that came out last week. Any thoughts? Backups are always a good idea, and you might want to be a little extra careful until experience proves me wrong. Bill

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