Squeak-dev February 2007

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161 participants
240 discussions

Low-space signals in production environments
by Andreas Raab 11 Feb '07

11 Feb '07

Hi Guys - I am just being very confused about the current behavior of Squeak in the case of memory allocation failure. In my use case I have incoming network requests which are handled at high I/O priority and need to allocate memory based on the size of the request. Given a malformed request, this can easily lead to an allocation failure which really should raise an error, be caught and be done with. However, there doesn't seem to be a way of handling low-space conditions by the client. In the case of an allocation failure, all that appears to be happening is that the low-space semaphore is being signaled with the obvious assumption that the low-space watcher will preempt the running process, make some space and continue. But equally obviously this just can't work if the running process is at a higher priority than the low-space process and since the running process recurses directly into #basicNew: again this will bring your system to a screeching halt. Since I can't possibly be the first person who noticed that (or at least I really don't hope I am) my question is, how do people deal with that situation in their production systems? I have never seen the issue discussed but I would expect that it has come up on some Seaside or other network-related lists. Right now I'm just thinking to do something like signaling an OutOfMemory error which as its default action would signal the lowspace condition, leaving the client with the option to handle the request differently if needed. Cheers, - Andreas

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Appending a character to a string
by Damien Cassou 11 Feb '07

11 Feb '07

Hi, Often, I want to concatenate a character to a string : self doSomethingWith: myString, Character cr, anotherString. However, #, only works with collections. I'm obliged to use #copyWith: instead. Is there a pattern to do this without using Streams ? Would it be desirable to enhance #, to allow concatenation of a single element ? Bye -- Damien Cassou

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Streaming on all collections
by Damien Cassou 11 Feb '07

11 Feb '07

Hello, why isn't it possible to stream over OrderedCollections ? stream := WriteStream on: OrderedCollection new. stream nextPut: $a this generates a 'attempt to index non-existent element in an ordered collection' The documentation of WriteStream>>nextPut: says : « Fail if the collection of this stream is not an Array or a String. » Can somebody explain me why it is forbidden ? -- Damien Cassou

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TestRunner with support for ALT+f
by Damien Cassou 11 Feb '07

11 Feb '07

Hello, I've created a patch to allow the user to use ALT+f in the TestRunner in order to search a class by name. http://bugs.impara.de/view.php?id=6006 Is it possible to include this in the next release? -- Damien Cassou

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[beginner] Tools flap disappeared
by Eugenii Philippov 11 Feb '07

11 Feb '07

Dear all, My flap 'Tools' has magically disappeared for no reason. How do I restore it back? I use Squeak 3.8.1. -- Best regards, Eugenii Philippov

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Re: Command Line Squeak/Scripting: Status?
by Brent Fulgham 10 Feb '07

10 Feb '07

> >>I'm curious about what the status of a Squeak setup for scripting is, > >>specifically for Linux? My end goal is being able to tell a user or run > >>programmatically from another script a Squeak script by typing something If one of these functions well enough to run programs from a script, let me know and I'll be glad to add Squeak to the "Computer Language Shootout" (http://shootout.alioth.debian.org). If need be, we can generate a squeak image with the benchmark classes in it, save the image, and run the script using the image. We do this for the Lisp and GNU Smalltalk implementations. -Brent

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[From the soapbox:] Update stream are essential!!!
by Jerome Peace 10 Feb '07

10 Feb '07

[From the soapbox:] Update stream are essential!!! > Andreas Raab andreas.raab at gmx.de > Wed Feb 7 00:49:35 UTC 2007 > > Jerome Peace wrote: > > My point is that 9 out of ten of the "smartest and > > most efficient Squeakers". choose to develop and > > express their vision, focus, with execution using > > update streams. > > Not in my experience. Except for the OLPC team I don't know any other > serious development effort that is based on change sets (if you disagree > name a few). The context in which I am talking is in maintaining an image. A development project with clear boundries may work very well for a time if it starts in MC. But once it starts there its locked in. It can't go back and forth between change set development and MC development. That is an unfortunate limitation. The more developed a package gets the more it the code will want to shift between packages or will want to be placed in a new package of its own. MC does not facilitate interpackage development changesets do. My position is not to go back to changesets and abandon MC. My position is that the two need to interoperate. Right now MC kills the usefulness of changesets because of its use of catagories to determine packages. That is the current unfortunate limitation. > And mostly I would claim for OLPC this is > due to historical > reasons, e.g., we've always used updates for eToys and > there isn't any > compelling reason to change that, in particular > considering that the > people involved have exhaustive experience with > managing update streams. > > > Process has a direct relationship to results. > > That is certainly true. > > > Anyone can update and save a current OPLC system in a > > handful of minutes. > > Yes, that is also true and one of the powerful things > about incremental > updates. On the other hand, try to port changes from > the OLPC image to > Squeak 3.9 and see how that goes. You'll go wildly > fishing through a > large number of changes desperately trying to figure > out what got > changed where and which effect it might have on other > ends of the system > and how (and if) it depends on changes done three > months ago. Been > there, done that. Monticello makes that kind of stuff > really easy - if > we need fixes in Qwaq's internal version of some > package we simply do > them and at some point we merely merge them back into > the public version > and we're done. We can always look what has changed > where, when and how. Okay, thats cool. In the context of Qwaq MC works. How big is Qwaq? How old is it? How long does it take to load and save? There is some difference in our experiences. > > In any case, those are different trade-offs for > different styles of work > and different goals. If you want to make progress > quickly, updates and > change sets might be for you. If you want to be able to > reflect about > the changes in an organized manner and move code > between various images > and versions, Monticello is pretty much the only choice. Yes. And when is it important to do each of those things? In the context of maintaining the image and repairing problems I want to be able to make progress quickly and later at leisure determine how to separate things into packages. Good repairs desire to be allowed to happen across packages. In the context of developing an alpha image I want frequent and wide distribution of the image to interested test pilots so that they can unmask bugs. The bugs can be patched. And the bugs uncovered by the fixes found. As I've tracked thru squeak I've had a better opportunity to find bugs because of they were hiding behind bugs I've patched. Also sometimes a hasty patch of mine has slipped into the stream and caused its own bug. I usally find it and fix it quickly. But if it can't get in to the update stream quickly then others waste a lot of time refinding the same bug instead of finding new ones. In the context of maintaining an image MC is not the completely right tool. It causes things to happen out of sequence and puts pressures on programmers to include messages in the wrong packages to avoid the work of getting multiple permission. (As Tim says "Don't ask me how I know this") > > Another way to look at the above is where you put the > time - updates are > mostly "back-end loaded" as they will require very > significant work if > you ever need to do anything with the code after it is > out, whereas > Monticello is more "front-end loaded", requiring to put > more thought in > before you do things. That means Monticello is > intrinsically slower to > develop initially but also more stable in the > long-term. Both of these > observations match exactly my experience with both > development styles. Yes, this is like the cathedral and the bazaar comparison. Or water and ice. My veiwpoint would say MC is slower to use and harder to change. Changesets are essential because they provide the mechanism for repair by rapid learning. Like McCready's gossamar condor being built out of balsa wood, piano wire, and duct tape. In the context of getting an image to work you need to be able to learn your lessons quickly, repair them and learn the lessons that are now newly exposed by the repairs. For that you need changesets. When things are working (lots of little repairs) taking stock and packaging what is willing to be packaged is a good way to preserve the gains. So my point is that choosing to make MC packages first and to build the image solely from those is out of sequence. > But by the end of the day I'd still insist that the main difference is > not in those tools but rather in the people working with them. > Yes, and good people will always seek the most appropriate tools and sequences for the job at hand. If a person has the spirit to learn from there mistakes. They will improve most rapidly in their quality and experience if they are allow to get thru thier mistakes quickly and often. "You get good results from good choices. You learn to make go choices from experience. You get experience from making bad choices." -- unknown. > Cheers, > - Andreas *** > [From the soapbox:] Update stream are essential!!! > > Andreas Raab andreas.raab at gmx.de > Wed Feb 7 10:23:22 UTC 2007 > > Jerome Peace wrote: > > This is a life destroying decision for the squeak > > community. > > > > Look at how fast the OPLC team develops improvements > > and look at the level of feedback they get. > > > > Now compare that with the glacial pace of the squeak > > image. > > (Just because I only noticed it and it's so fitting in > this discussion) > Even if you do consider The Image to be the sine qua > non of Squeak, you > might want to have a look at: > > http://weeklysqueak.wordpress.com/2007/02/04/ > recent-squeak-packages-releases-2/ > > which may give you a different view of the "glacial" > pace at which the > community as a whole moves. There is a whole lot of > stuff going on if > you are willing to look beyond the image in front of > you. > > Cheers, > - Andreas *** Cool. Good point. Thank you for the engaging conversation so far. Yours in curiosity and service, -- Jerome Peace > > ____________________________________________________________________________________ Looking for earth-friendly autos? Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center. http://autos.yahoo.com/green_center/

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Command Line Squeak/Scripting: Status?
by Aaron Reichow 09 Feb '07

09 Feb '07

Hi everyone! I'm curious about what the status of a Squeak setup for scripting is, specifically for Linux? My end goal is being able to tell a user or run programmatically from another script a Squeak script by typing something like: ./hallowelt.sq where hallowelt.sq is a file like- #!/usr/bin/squeak -filein Transcript show: 'Hello World'; cr. I also would really, really like, the ability to pass command line arguments, so: ./hallowelt2.sq Aaron #!/usr/bin/squeak -filein Transcript show: 'Hello World '; show: (Argv at: 2); cr. I don't need anything very fancy, nor do I need a certain version of the image or much in the way of library support. The one library I do need is PostgreSQL suport. In my newish job, I'm starting to move various reports that pull data from a super flexible object- relational database setup from Java to Python. I'd like to do this in Squeak, obviously! But due to a few factors, the first couple I've done are in Python. I don't need to do any elaborate stuff, I don't need a curses interface, etc. I'm fine with most of it all being in the image, with the hallowelt.sq file in this example being nothing other than something that runs the squeak VM but some how tells the image to run a certain script through a command line argument. I'd do development on a regular Squeak VM on my Mac, then deploy to the server where someone else would run the reports. Worst case I could roll this myself, skipping commandline arguments and using config files that the report-runner has to edit to specify the date range rather than just doing it on the command line. But I'd rather a more Unix-feeling solution. I personally don't need anything like input and output through pipes, but I might find a use for them later if the option was there. So, what's up with Squeak for this sort of setup? What are my options? Do I have any useable ones? Regards, Aaron

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To PR and Web teams (small idea)
by Esteban Lorenzano 09 Feb '07

09 Feb '07

What about a "success stories" link in squeak.org? It would be useful for ours in order to promote the use of squeak in our day-jobs (they are always reluctant to introduce something "new"), and to get some extra visibility on the net. We could organize the page in subtopics like: "Educational successes", "Industry successes", etc. Cheers, Esteban -- "Querer es suscitar las paradojas" Camus. El míto de Sísifo.

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re: "Steps Toward the Reinvention of Programming" (was "Making Squeak more accessible...")
by Craig Latta 09 Feb '07

09 Feb '07

Jecel writes: > I found this plan interesting: > > http://irbseminars.intel-research.net/AlanKayNSF.pdf Given that work, is there any point to continuing with the Spoon[1] project? E.g., will there be a need for a minimal and extensible object memory, and if so, has that problem already been solved and I just haven't heard about it? Or does the Spoon work complement this project somehow? wondering, -C [1] http://netjam.org/spoon -- Craig Latta http://netjam.org/resume

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