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

[Pharo-project] leaking semaphores
by Milan Mimica March 2, 2012

March 2, 2012

Hi! I am continuing my search of why does my remote headless image run out of semaphores eventually. I have found the culprit this time. It is most definitively related to RFBServer. I am using version 38 from http://source.lukas-renggli.ch/unsorted. Every time I disconnect from the image with my VNC client (I click the disconnect icon) the count of leaked semaphores increases by 3. Since there is 3 semaphores per socket, I guess this is related to sockets. Now what do I do? What do I check? I am running the a Pharo image and Cog I got from CI server yesterday. This is the script I use to count leaked semaphores: | semaphores arr res | arr := ExternalSemaphoreTable unprotectedExternalObjects. semaphores := arr reject: #isNil. res := semaphores collect: [:sema | sema pointersTo reject: [:ptr | ptr == arr or: [ptr == semaphores ] ] ]. res := res select: [ :each | each isEmpty ]. res size. -- Milan Mimica http://sparklet.sf.net

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[Pharo-project] Nautilus version 4.0.4
by Benjamin March 2, 2012

March 2, 2012

Hi guys, I really want to thank you all for your feedbacks which give me the will to always add cool features to Nautilus. Thanks to that, let me introduce the new stable version with some new features: - better groups (now the granularity is method and no longer class) - better algorithm for coloring protocols and methods - more menu entries and shortcuts - Monticello integration - OCompletion integration - a lot of new icons :) (and some cleans in the code but ^^) Thanks every one for your good energy :) Ben

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[Pharo-project] fun with NBOpenGL
by StÃ©phane Ducasse March 1, 2012

March 1, 2012

Igor coded with me one hour to show me step by step how to produce a rotating pyramid in Pharo :) Have fun (igor will update the configurationOfNBOpenGL to load the latest file).

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[Pharo-project] can this be done via modification to the Squeak/Pharo IDE?
by Lawson English March 1, 2012

March 1, 2012

http://vimeo.com/36579366 Lawson

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[Pharo-project] does anybody use for business the Native Mac menus?
by StÃ©phane Ducasse March 1, 2012

March 1, 2012

Hi guys we are thinking that we want to (rewrite) remove the support for native mac menus because it goes against the flow of things and the cleanup of the events we are doing. So before removing them we would like to assess if we should really support that or not now. Stef

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Re: [Pharo-project] [squeak-dev] Spoon presentation 2012-02-24
by Chris Muller March 1, 2012

March 1, 2012

You showed us this earlier in the week -- and the feedback then was, "voice-over, please." When the music started I hoped perhaps you were going to sing it to us. :) It's nice demo, but so far I've only seen the components that are IN Spoon -- I am interested in seeing an OUTPUT of Spoon. Anything to take me to the next-level of understanding and confidence about it.. On Fri, Feb 24, 2012 at 9:01 AM, Craig Latta <craig(a)netjam.org> wrote: > > Hi-- > > Â Â This is a fly-through of my next presentation about Spoon[1]. I > hope to present it at the next Pharo conference, 24-25 May 2012 in > Lille, France. > > Â Â http://tinyurl.com/8y2x3rp (wordpress.com) > > > Â Â thanks for any feedback! > > -C > > [1] http://netjam.org/spoon > > -- > Craig Latta > www.netjam.org/resume > +31 6 2757 7177 > + 1 415 287 3547 > >

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[Pharo-project] Is athens configuration loading?
by StÃ©phane Ducasse March 1, 2012

March 1, 2012

Can we play with it :)? Stef

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[Pharo-project] FFI on 1.3: compile fields
by Schwab,Wilhelm K March 1, 2012

March 1, 2012

Does 1.3 by default not create field accessors? Why is that? I thought nothing was happening. Bill

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Re: [Pharo-project] Nearly limitless Image: revisited.
by Janko MivÅ¡ek Feb. 29, 2012

Feb. 29, 2012

Good compromise is a step by step approach, something like: 1.step: image based persistence up to 1GB with hourly snapshot 2.step: parts migrated to Fuel and file based persistence 3.step: Gemstone, with "images" running in parallel (well, any DB with images in parallel, Gemstone is certainly the easiest to scale from image based persistence) 1GB limit is here just for simplicity, you can probably go further with 64bit images. Advantages: - very very simple start - freedom of pure OO modeling, - good enough for probably 90% of all projects - fastest way from your dreams to reality - speed of development - no impedance mismatch, no ORM nightmare - you won't believe how much data you can put in 1GB image - speed because of always in-memory data processing - you can always scale further if you make your design from the start with above steps in mind - reliability good enough, on reliable hardware probably even better than more complex solutions. Main reason: simplicity. Disadvantages: - you easy forgot to include later scalability requirements in upfront design - such scaling is easy only to OO database while migrating to NoSQL (not to mention SQL) database later is very hard if not possible - up to about 1GB only, because of GC problems as Igor described - active users limit (number of requests/s) - single point of failure - corrupted image will loose all data (but good backup approach helps) - undetected image corruption fear (after many otherwise successful snapshots, causing non-startable image) - lengthy snapshots of bigger images (can be improved with two step snapshots, first in memory, then on disk) - loss of data between snapshots in case of power or machine failure (but this is very rare those days) Bet regards Janko S, Igor Stasenko piÅ¡e: > Incidentally, we had a little chat with Marcus yesterday about that. > > No, i don't think it is feasible to use single image to store everything. > It is convenient, cheap and of course it is way better than dealing > with communicating with external DB/servers whatever. > > But there's one thing you should know already: the days of vertical > growth is over. > > Running a service (under VM or not) on a single machine is asking for troubles: > - limits on load > - susceptible to power outage and other reliability problems > etc > > Also, think that the amount of data you need to process correlates > with CPU horsepower available. > Which means that yes, you can run a huge image with 64Gb data in it.. > but that means that responsiveness > of your service will quite often fall beyond any usability limits. > > If we look in terms of VM and pick only one thing - garbage collection, > you will see that there is certain limits beyond which a performance > will drop too much, so you naturally > will start thinking about ways to split data to separate chunks and > run them on different machines/VMs. > > It is because GC's mark algorithm is O(n) bound, when n is total > number of references between objects, > and GC's scavenge algorithm is at best O(n) bound where n is total > number of objects in object memory, > and at worst is where n is total memory used by objects. > No matter how you turn it, i just wanted to indicate that time to run > GC is in linear dependency from the amount of data. > > Yes, we might invest a lot of effort in making GC more clever, more > complex and more robust.. but no matter what you do, > you cannot change the above facts. It means, that any improvements > will be about diminishing returns, but won't change the picture > radically. > > That means that sooner or later you will have to deal with it: a > problem of splitting data on multiple independent chunks, > and making your service to run on multiple machines , in order to use > more CPU power, more memory and be more reliable etc. > At this point, your main dilemma is to invent a fast and robust > interfaces to communicate between images or between image(s)/ database > etc. > > We should concentrate on things which dealing with inter-image > communication and image-database communication, > because it is the only way to ensure that we will answer upcoming > future problems. Relying on using a single huge image is way to > nowhere. > -- Janko MivÅ¡ek Aida/Web Smalltalk Web Application Server http://www.aidaweb.si

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[Pharo-project] New CogVM binaries as per VMMaker.oscog-eem.150/r2537
by Eliot Miranda Feb. 29, 2012

Feb. 29, 2012

http://www.mirandabanda.org/files/Cog/VM/VM.r2537/ CogVM binaries as per VMMaker.oscog-eem.150/r2537 Disable filling of the weakRoots table during fullGC. Report remappable oop and weak root table overflows as errors. Make primitiveObjectAtPut fail if used to store other than a SmallInteger into the method header. Better error message for inability to thread. Load function pointer early in ThreadedFFIPlugin's invocation checking sequence. This must come early for compatibility with the old FFIPlugin. Image-level code may assume the function pointer is loaded eagerly. Add 1007,1008 & 1009 attribute info to version info on linux, & 1009 on Windows. Add -version option to Mac VM (with similar info to linux). Include vm-display-fbdev on linux. Exclude fbdev in the newspeak build. Simplify ticker for older linuxes. -- best, Eliot

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