November 2012 - Pharo-dev - lists.pharo.org

Re: [Pharo-project] Don't ever ever halt in #startUp:

by Sebastian Nozzi

Hey there Sebastian, I feel your pain. Unfortunately there seem to be *many* places / situations where "halting" is a very bad idea and renders your image unusable. That's why I think it would be a good idea to have a "list" of these places (in the documentation and in the Pharo "welcome" Workspace), and maybe the technical reasons behind them. Something that I did a couple (!!) of times until I learnt the lesson was to halt withing a Morph>>drawnOn:. If you do, then there goes your UI painting/event processing thread (solution: debug your Morph from outside, passing a NullCanvas). It was also possible for me, more than once, to "hang" the image beyond recovery (CMD-dot did not help) if "Delaying" ((Delay forMilliseconds: 200) wait) within the UI thread in an infinite recursion (by mistake). As for "rescuing it"... can the "recent changes" help you? In your case you would be directly reading the ".changes" file... Not really rescuing your image, but extracting and saving your work... (and migrating to a new image). This is very annoying, I know. Been there a couple of times (although with less serious work than yours). In my opinion something needs to change in this area. These are huge productivity losses, and I fear that many new users (*) would at this point turn their backs on Smalltalk never to look back again. Best regards, Sebastian N. (*) or senior developers evaluating the possibility to use Pharo in their companies. 2012/11/8 Sebastian Sastre <sebastian(a)flowingconcept.com> > â¦I mean ever. > > Because you'll screw your image. > > Mostly when you also are on OS X but, for some crazy reason of the > Universe, your TimeMachine was not operating normally on your laptop while > coding. > > Aaaaand you weren't committing in the monticello repo because it was work > in progress and you were expecting to reach some goal. > > Ever. > > Soâ¦ > > I'm in that situation with an image now :( > > I've the false good idea of putting a halt in an SomeApp class>>startUp: > method and now, when I open the image, it tries to, stays for about 2 > seconds and crashes. > > Any of you guys have a workaround/hack to rescue it? > > sebastian <https://about.me/sebastianconcept> > > o/ > > PS: I've tried with startup.st with the code that removes that method but > no luck. > > > >

Nov. 8, 2012

Re: [Pharo-project] [NativeBoost] pass an array of args to external function

by StÃ©phane Ducasse

On Nov 8, 2012, at 9:13 PM, Sven Van Caekenberghe wrote: > > On 08 Nov 2012, at 20:29, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> wrote: > >> I told you several time, do you think that a guy do not understand what is a pointer because he does not know how to write it >> in C? >> Give a chance to professionals to learn. We are not talking about explaining what is a pointer, but explaining the >> potential problems and challenges >> >> With your reasoning, I should stop programming because there are so many things that I did not learn in school >> and I would not have no chance to learn from this community. So with that reasoning I should better stop working in Smalltalk >> and look for another language! > > I think he meant it as a general warning ;-) yes I know > > The things is, as long as its pure Smalltalk, you are protected by a very good dynamic type system that cannot really be broken, i.e. the object illusion is kept (bounds checking, blah blah â¦) indeed but this means that with a little care we should be able to explain points. I do not see them as difficult, just full of little details. > But once you start using C pointers, you can very easily do something wrong. It might be a very subtle error and it might not manifest itself immediately, alas there won't be a Debugger popping up, just a coredump. > > Pharo is actually pretty/very stable in day to day use, it should stay that way. oh! yes! Stef > > Sven > > -- > Sven Van Caekenberghe > http://stfx.eu > Smalltalk is the Red Pill > > > >

Nov. 8, 2012

Re: [Pharo-project] [Pharo-users] Recovering Changes from a broken image

by Sven Van Caekenberghe

On 08 Nov 2012, at 21:09, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> wrote: > > On Nov 8, 2012, at 9:03 PM, Sven Van Caekenberghe wrote: > >> Hi, >> >> One of the cool things of Smalltalk's images/changes file is that you can do a World Menu > Tools > Recover lost changesâ¦ to get back most [1] of your code in case your image/OS/machine suddenly crashed or you forgot to save your image or commit your Monticello packages. >> >> But we all have encountered the situation where the image is broken, saved in such a state that it no longer starts up properly. In that case your code might seem lost forever. >> >> No, it is not ! >> >> Two days ago I had this problem myself and I remembered something Marcus said some time ago: you can access the changes file of one (in casu your broken image) from another (working) image to select/recover the changes you want. It worked perfectly. >> >> The easiest procedure it to copy the .changes file from the broken image and rename its extension to .cs and then open it from a World Menu > Tools > File Browser and open a Changes browser on it. > > We should add a recover from another image shortcut. Yes! Good idea. >> I found this very useful. This is a really important technique to be aware of. >> >> Sven >> >> [1] Sadly, not everything is logged in the changes file: creation of new classes, method deletions are not recorded. > > Yes we should change that. > Ezequiel started to work on a new description of changes. OK.

Nov. 8, 2012

Re: [Pharo-project] [NativeBoost] pass an array of args to external function

by Sven Van Caekenberghe

On 08 Nov 2012, at 20:29, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> wrote: > I told you several time, do you think that a guy do not understand what is a pointer because he does not know how to write it > in C? > Give a chance to professionals to learn. We are not talking about explaining what is a pointer, but explaining the > potential problems and challenges > > With your reasoning, I should stop programming because there are so many things that I did not learn in school > and I would not have no chance to learn from this community. So with that reasoning I should better stop working in Smalltalk > and look for another language! I think he meant it as a general warning ;-) The things is, as long as its pure Smalltalk, you are protected by a very good dynamic type system that cannot really be broken, i.e. the object illusion is kept (bounds checking, blah blah â¦) But once you start using C pointers, you can very easily do something wrong. It might be a very subtle error and it might not manifest itself immediately, alas there won't be a Debugger popping up, just a coredump. Pharo is actually pretty/very stable in day to day use, it should stay that way. Sven -- Sven Van Caekenberghe http://stfx.eu Smalltalk is the Red Pill

Nov. 8, 2012

Re: [Pharo-project] [Pharo-users] Recovering Changes from a broken image

by StÃ©phane Ducasse

On Nov 8, 2012, at 9:03 PM, Sven Van Caekenberghe wrote: > Hi, > > One of the cool things of Smalltalk's images/changes file is that you can do a World Menu > Tools > Recover lost changesâ¦ to get back most [1] of your code in case your image/OS/machine suddenly crashed or you forgot to save your image or commit your Monticello packages. > > But we all have encountered the situation where the image is broken, saved in such a state that it no longer starts up properly. In that case your code might seem lost forever. > > No, it is not ! > > Two days ago I had this problem myself and I remembered something Marcus said some time ago: you can access the changes file of one (in casu your broken image) from another (working) image to select/recover the changes you want. It worked perfectly. > > The easiest procedure it to copy the .changes file from the broken image and rename its extension to .cs and then open it from a World Menu > Tools > File Browser and open a Changes browser on it. We should add a recover from another image shortcut. > > I found this very useful. This is a really important technique to be aware of. > > Sven > > [1] Sadly, not everything is logged in the changes file: creation of new classes, method deletions are not recorded. Yes we should change that. Ezequiel started to work on a new description of changes. > > -- > Sven Van Caekenberghe > http://stfx.eu > Smalltalk is the Red Pill > > > >

Nov. 8, 2012

Re: [Pharo-project] [NativeBoost] pass an array of args to external function

by StÃ©phane Ducasse

jimmie ***THANKS*** I'm in the same situation even if I read several lectures and books on C. So I want a tutorials that takes us into account and I'm sure that this is faisable. Just need care, love and time. STef On Nov 8, 2012, at 8:58 PM, Jimmie Houchin wrote: > On 11/8/2012 1:30 PM, StÃ©phane Ducasse wrote: >>> And you can be pretty sure that most pharoers (including myself) have >>> a pretty vague notion about malloc/free, combined with the internals >>> of an third party C library, that makes a pretty unstable field. >>> >>> Again, no silver bullets here, but less arrogance and more examples! >> +1 >> but we can learn and learn fast with a good tutorial that puts the right amount >> of information in perspective. >> >> Stef > I am aperson who has no background in C or similar languages, but would like to learn how to use NB to be able to access methods in DLLs. > > My question is, without becoming a C programmer, what is a sufficient level of knowledge of C to be able to use NB well? > > What is a good path to acquiring a sufficient level of knowledge? > > Thanks for any information. > > Jimmie >

Nov. 8, 2012

[Pharo-project] Recovering Changes from a broken image

by Sven Van Caekenberghe

Hi, One of the cool things of Smalltalk's images/changes file is that you can do a World Menu > Tools > Recover lost changesâ¦ to get back most [1] of your code in case your image/OS/machine suddenly crashed or you forgot to save your image or commit your Monticello packages. But we all have encountered the situation where the image is broken, saved in such a state that it no longer starts up properly. In that case your code might seem lost forever. No, it is not ! Two days ago I had this problem myself and I remembered something Marcus said some time ago: you can access the changes file of one (in casu your broken image) from another (working) image to select/recover the changes you want. It worked perfectly. The easiest procedure it to copy the .changes file from the broken image and rename its extension to .cs and then open it from a World Menu > Tools > File Browser and open a Changes browser on it. I found this very useful. This is a really important technique to be aware of. Sven [1] Sadly, not everything is logged in the changes file: creation of new classes, method deletions are not recorded. -- Sven Van Caekenberghe http://stfx.eu Smalltalk is the Red Pill

Nov. 8, 2012

Re: [Pharo-project] [NativeBoost] pass an array of args to external function

by Jimmie Houchin

On 11/8/2012 1:30 PM, StÃ©phane Ducasse wrote: >> And you can be pretty sure that most pharoers (including myself) have >> a pretty vague notion about malloc/free, combined with the internals >> of an third party C library, that makes a pretty unstable field. >> >> Again, no silver bullets here, but less arrogance and more examples! > +1 > but we can learn and learn fast with a good tutorial that puts the right amount > of information in perspective. > > Stef I am aperson who has no background in C or similar languages, but would like to learn how to use NB to be able to access methods in DLLs. My question is, without becoming a C programmer, what is a sufficient level of knowledge of C to be able to use NB well? What is a good path to acquiring a sufficient level of knowledge? Thanks for any information. Jimmie

Nov. 8, 2012

Re: [Pharo-project] What did you guys do to startup-time ?

by StÃ©phane Ducasse

Thanks Miloslav This is strange because we are not really satisfied from this point of view. There are a lot of cleaning to do to get a snappy morphic. Stef > Who snuffed the poor guy ? I donât know what magic (yea, i know, not just one magic, bunch of magix really ;-) you did but ... I downloaded Pharo 2.0 to give it a whirl (I love smalltalk and keep playing with it / write an app in it every once in a while), unzipped it, doble clicked the binary and the window jumped me so fast i nearly fell of my chair (a positive WTF moment ;-). > > And not just old Mr. Startup Time, you killed Lady Delay too. I remember squeak / older pharo versions feeling a bit sluggish (a slight delay between clicking and the menu popping up / whatever), but now it is blazing fast. > > Just saying âGreat workâ would be an understatement / denigration. > > * rausm deeply bows in silent awe

Nov. 8, 2012

Re: [Pharo-project] New command line option: load updates

by StÃ©phane Ducasse

Cool! I like the noise of the falling of large bash scripts. The lesser the better Stef > Hi, > > There is now a command line option to load updates. > > To test it: > > wget --quiet -qO - http://pharo.gforge.inria.fr/ci/ciPharo20NBCog.sh | bash > > ./vm.sh Pharo.image update > > What is does it to load updates, then snapshot and quit. > > The idea is to use this in the new CI setup so we don't need any external scripts. > > -- > Marcus Denker -- http://marcusdenker.de > >

Nov. 8, 2012