Squeak-dev October 2007

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151 participants
195 discussions

Re: Concurrent Futures
by Rob Withers 01 Nov '07

01 Nov '07

Igor, why don't you add your ideas to http://wiki.squeak.org/squeak/6012. . . . ----- Original Message ---- From: Igor Stasenko siguctua(a)gmail.com > On 30/10/2007, Rob Withers <reefedjib(a)yahoo.com> wrote: > > > It seems to me that you are building event-loops in the VM. Consider > > anObject that is sent a msg on thread 1, so he is assigned to thread 1 and > > you start processing it with thread 1. In the meantime, 3 msgs are sent to > > this object on threads 2, 3, and 4. Each message send is scheduled for > > processing by thread 1, when it becomes available. There is your > > event-loop. > > > > Yes, exactly. I'm still unsure if it really needed for all objects in > system. For instance, the true/false/nil object are just singletons > without any internal state. Thus scheduling them into single thread of > execution can be simply omitted. The same goes for SmallIntegers, which while not singletons, are not mutable. Perhaps Characters are also candidates for this. These are PassByConstruction objects, which means they are always local. PassByCopy is another type of PassByConstruction, where a copy is marshalled to the other side. > The other thing which bothers me is a reflection. Should we expose a > properties of native threads at language side (for using/showing them > in debugger)? Or how well new contexts will deal with continuations, > which is used in seaside.. I think each process should know which thread id it is running in. In my model, the process stays with the thread, while in yours I am not sure. A message to a VatRef to an object in a different Vat, would be sent asynchronously and scheduled in the other Vat for it's thread to process. BTW, in another email you asked about how passing a ref between Vats (Islands) guaranteed that all msgs to it would go to the home Vat. The answer is that a ref to a Vat local object, being passed as an arg to a msg send to a VatRef to an object in a different Vat, would be translated into a VatRef back to the origin Vat when the MsgSend marshalled it's arguments to the 2nd Vat. No ref with direct memory access would ever be allowed to be passed to another Vat. > > But the primitive may have internal state that can't be shared. > > > I know, but i'm talking about basic primitives which used most > frequently and operating only with object memory. Such primitives > usually don't have any internal state, or using an interpreter state. Ok, so from the link above, the ProtectedPrimitives would not always be protected. > > All other primitives which have internal state should be reviewed. > And at first stages we could add support for scheduling all these > 'old' primitives into single 'main' thread. So they will work as in > current VM not knowing that VM is actually multithreaded. I was thinking we mutex protect them, but still allow different threads to use them. > I'd like to hear more critics about such model :) If it proves to be > viable and much or less easily doable (comparing to other models) then > i could start working on it :) Go for it!! cheers, Rob

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[ANN] Smalltalk flyer now in German
by Damien Cassou 31 Oct '07

31 Oct '07

Hi, thanks to Markus Gälli, we now have the Smalltalk flyer in German too. More information at: http://damien.cassou.free.fr/ I hope to receive the Japanese version soon. If you want to translate the flyer to your own language, please download https://svn.squeak.org/Advertisement/flyers/smalltalk/english.tex and translate the sentences. Bye -- Damien Cassou

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Re: Concurrent Futures
by Jason Johnson 31 Oct '07

31 Oct '07

On 10/31/07, Jecel Assumpcao Jr <jecel(a)merlintec.com> wrote: > I would like to mention some of my previous work in this area: > > - tinySelf 1 (1996) > http://www.lsi.usp.br/~jecel/tiny.html#rel1 > <snip> > > - 64 node Smalltalk machine (1992) > http://www.lsi.usp.br/~jecel/ms8702.html > <snip> > > - operating system in an Objective-C like language (1988) > http://www.lsi.usp.br/~jecel/atos.html (this page has download links but > the text still hasn't been written) > <snip> > > -- current model -- > <snip> > This thread is really getting good! :) > Speaking of hardware, I would like to stress how fantastically slow > (relatively speaking) main memory is these days. If I have a good > network connecting processor cores in a single chip then I can probably > send a message from one to another, get a reply, send a second message > and get another reply in the time that it takes to read a byte from > external RAM. So we should start thinking of DDR SDRAM as a really fast > disk to swap objects to/from and not as a shared memory. We should start > to take message passing seriously. > > -- Jecel Wonderful point. I suppose a big part of the problem I have had in this thread has been not accepting that a lot of people don't realize the reality of your comment. I'm not proposing to abandon the shared-state programming model *only* because it's too hard to program in. My *biggest* motivation is the fact that it *wont scale* to tomorrows systems. I would just hate to see Squeak put a ton of work in just so we can run out and announce that we have "real" concurrency, only to find out that everyone else already discovered it can't scale and moved on. Smalltalk for me is about being *ahead* of other platforms. Not decades behind.

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the Syntax Error dialog
by Alejandro Martínez 31 Oct '07

31 Oct '07

Hi. I'm trying the Damien's sq3.10-7158dev07.10.2.image with SqueakV39.sources When I tried to update Monticello and Monticello Configuration from the Universe Browser, I get a Syntax Error dialog, it seems there's no easy way to bypass this one. And the same error dialog updating Monticello from Monticello, even tried installing MC2. Any hint on this? I remember this could happen using the new compiler, but in the Preferences Browser there's no Compiler category to disable #compileUseNewCompiler, and BTW it's this image using the new compiler? how to check that? Thanks Alejandro

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Object orientation - can you have too much of a good thing?
by Michael Davies 30 Oct '07

30 Oct '07

There's an interesting post and discussion here: http://weblog.raganwald.com/2007/10/too-much-of-good-thing-not-all.html

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2 more movies from OOPSLA
by Göran Krampe 30 Oct '07

30 Oct '07

Hi! Read more at: http://goran.krampe.se/blog (might need to do reload in your browser, Rublog seems to use caching headers) regards, Göran PS. More coming but my server is starting to get full - might need to serve from home or something.

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Proposed 3.8.2 updates
by Michael Rueger 30 Oct '07

30 Oct '07

Hi all, attached a set of potential updates for 3.8.1 to move it to 3.8.2. Included are 6748advance382a.cs 6750stringAndCharFixes-mir.cs (really a collection of fixes from 3.9/3.10) 6755SemaCritical-ar.cs 6754DelayStartup-ar.cs 6753DelayTweaks-ar.cs 6751SafeDelay-ar.cs 6752FreezeFix-ar.cs 6747advance381.cs 6749categoryspeedup-al.cs Comments, suggestions for other fixes etc welcome! Michael

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Re: Concurrent Futures
by Rob Withers 30 Oct '07

30 Oct '07

----- Original Message ---- From: Igor Stasenko siguctua(a)gmail.com > > These are > > PassByConstruction objects, which means they are always local. PassByCopy > > is another type of PassByConstruction, where a copy is marshalled to the > > other side. > > Hmm i can't follow you here. Could you elaborate? Sorry, this is terminology from E. They have a whole terminology describing how objects get passed over the wire between Vats. http://erights.org/elib/distrib/obj-passing.html http://erights.org/elib/concurrency/refmech.html The restriction that PassByCopy objects are selfless, immutable and transparent certainly apply to SmallIntegers, true, false, and nil. I don't know about Characters, but that is their terminology. We can define ourselves. Rob

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Nokia 770 for $135
by Jon Hylands 30 Oct '07

30 Oct '07

If anyone is interested, the Nokia 770 (brand new) is selling for $135 USD ($130 in Canada). http://www.mobileplanet.com/p.aspx?i=141019 for US customers http://www.expansys.ca/p.aspx?i=141019 for Canadian I just ordered one last night to play with. What's the status of the VM on it? Is there support for the buttons? Later, Jon -------------------------------------------------------------- Jon Hylands Jon(a)huv.com http://www.huv.com/jon Project: Micro Raptor (Small Biped Velociraptor Robot) http://www.huv.com/blog

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#copyStack on Error
by Rob Withers 30 Oct '07

30 Oct '07

Let's say I have a process which is consuming events off of a queue. I don't want the process to ever terminate. If the handling of one of these events results in an Error, even a Halt, this process will be opened in the Debugger and the user could choose to abandon or terminate at will. Is it possible to copyStack the activeProcess and open that stack in the Debugger for the user. This way if the User terminates the process, it won't affect the main process. I wonder though, if the user resumes, will two proceses be consuming events from the queue? Perhaps I can copyStack using copyTo: a specific context that is above the point of consuming events, such that a resume will cause the copied stack to go away. Thanks for any assistance, Rob

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