April 2011 - Pharo-dev - lists.pharo.org

Re: [Pharo-project] new Cog VMs uploaded

by Eliot Miranda

On Fri, Apr 29, 2011 at 9:04 AM, Philippe Marschall <kustos(a)gmx.net> wrote: > On 27.04.2011 19:23, Eliot Miranda wrote: > > Philippe, > > > > can you please profile before and after? This could very well be to > > do with the additional cost of shallowCopy for contexts, but it is > > inevitable that a correct implementation is going to be more expensive > > than the simple block-copy. The new implementation can be optimized, > > but we need to profile first to be sure we're tilting at the relevant > > windmill. > > > What kind of profiling do you have in mind, MessageTally? > Yes, that would be fine. Thanks! best, Eliot > > Cheers > Philippe > > >

April 29, 2011

Re: [Pharo-project] new Cog VMs uploaded

by Philippe Marschall

On 27.04.2011 19:23, Eliot Miranda wrote: > Philippe, > > can you please profile before and after? This could very well be to > do with the additional cost of shallowCopy for contexts, but it is > inevitable that a correct implementation is going to be more expensive > than the simple block-copy. The new implementation can be optimized, > but we need to profile first to be sure we're tilting at the relevant > windmill. What kind of profiling do you have in mind, MessageTally? Cheers Philippe

April 29, 2011

Re: [Pharo-project] new Cog VMs uploaded

by Philippe Marschall

On 27.04.2011 19:24, Eliot Miranda wrote: > > > > > can you post a stack trace from gdb? Also, what linux system and what > image are you using? r2382 fixed it Cheers Philippe

April 29, 2011

Re: [Pharo-project] Counting Messages as a Proxy for Average Execution Time in Pharo

by Igor Stasenko

On 29 April 2011 01:03, Stefan Marr <pharo(a)stefan-marr.de> wrote: > > On 29 Apr 2011, at 00:32, Nicolas Cellier wrote: > >> >> However, as I understand it, it's entirely up to user to write code >> exploiting parallel Process explicitly right ? > Sure, you have to do: n times: [ [ 1 expensiveComputation. ] fork ]. > > I don't belief in holy grails or silver bullets. > Automatic parallelization is something nice for the kids, like Santa Clause or the Easter Bunny... > Indeed :) People tend to forget that parallel algorithms are different by nature, and there is no way to automatically convert arbitrary single-threaded algorithm to parallel one, without thinking about rearranging data structures and control flow. > > Best regards > Stefan > > -- > Stefan Marr > Software Languages Lab > Vrije Universiteit Brussel > Pleinlaan 2 / B-1050 Brussels / Belgium > http://soft.vub.ac.be/~smarr > Phone: +32 2 629 2974 > Fax: Â +32 2 629 3525 > > > -- Best regards, Igor Stasenko AKA sig.

April 29, 2011

Re: [Pharo-project] [Pharo-users] [COTDC] 56 - HostFont

by laurent laffont

On Fri, Apr 29, 2011 at 4:24 PM, Marcus Denker <marcus.denker(a)inria.fr>wrote: > > On Apr 28, 2011, at 6:23 PM, laurent laffont wrote: > > > Today: HostFont > > > Seems to be unused. I vote for removing. (together with IdentityGlyphMap) > Agree. I like rule #2 :) Laurent. > > Marcus > > > > -- > Marcus Denker -- http://www.marcusdenker.de > INRIA Lille -- Nord Europe. Team RMoD. > > >

April 29, 2011

Re: [Pharo-project] Counting Messages as a Proxy for Average Execution Time in Pharo

by Alexandre Bergel

It makes perfect sense to me. Alexandre On 29 Apr 2011, at 10:09, Toon Verwaest wrote: > Actually if you listen to Guy Steele's talk the whole point is to let the developer be even more ignorant than you are now. > > You shouldn't write "do" loops that start at the beginning and go until the end. You should just say that you want the calculation done and that your intent is that you have visited everything. And then of course you might have dependencies etc... but the idea is generally, don't say how to do it, just declare what you want as a result. > > Of course, it doesn't immediately match what we are used to doing: telling the computer how we want things done; but you can't really say that you have to tell the computer more about parallelization. It's exactly the opposite. > > On 04/29/2011 05:05 PM, Alexandre Bergel wrote: >> Interesting result. But still, I feel that the computer should be able to do some inference. This could be at runtime, at compile time or during the development. I think than expecting the user to have the knowledge about how to parallelize an application is too much asking. >> >> I will read Charlotte's work. >> >> Alexandre >> >> >> On 29 Apr 2011, at 09:58, Toon Verwaest wrote: >> >>> I have a hunch that Stefan is referring to the PhD thesis of Charlotte Herzeel without giving names. As far as I understood from my discussions with her (and her talks), it generally doesn't really pay off to automatically parallelize on branches. You get minimal speedups (1% at best). >>> >>> I tend to agree with Stefan / Michael / Guy Steele... Maybe you don't need much, but the mapreduce style is the minimum requirement to give the language enough "wiggle room" to automatically parallelize stuff. But it DOES require you to restructure your application in a slightly more declarative fashion. >>> >>> cheers, >>> Toon >>> >>> On 04/29/2011 04:55 PM, Alexandre Bergel wrote: >>>> Hi Stefan, >>>> >>>> I though about your email. I do not understand why automatic parallelization is not the way to go. In my opinion, the computer has much more knowledge about the programmer about where side effects appear and where to cut or split a computation. >>>> >>>> Actually, if I want to be provocative, I would say that parallelization cannot be effective without being automatic. For a similar reason that the compiler will always know better than me how to properly allocate registers. >>>> >>>> I feel it would be cheaper for me to buy a faster computer than to learn how to program in a multi-core fashion. >>>> >>>> Cheers, >>>> Alexandre >>>> >>>> >>>>>> However, as I understand it, it's entirely up to user to write code >>>>>> exploiting parallel Process explicitly right ? >>>>> Sure, you have to do: n times: [ [ 1 expensiveComputation. ] fork ]. >>>>> >>>>> I don't belief in holy grails or silver bullets. >>>>> Automatic parallelization is something nice for the kids, like Santa Clause or the Easter Bunny... >>>> >>> > > -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

April 29, 2011

Re: [Pharo-project] Counting Messages as a Proxy for Average Execution Time in Pharo

by Alexandre Bergel

Interesting result. But still, I feel that the computer should be able to do some inference. This could be at runtime, at compile time or during the development. I think than expecting the user to have the knowledge about how to parallelize an application is too much asking. I will read Charlotte's work. Alexandre On 29 Apr 2011, at 09:58, Toon Verwaest wrote: > I have a hunch that Stefan is referring to the PhD thesis of Charlotte Herzeel without giving names. As far as I understood from my discussions with her (and her talks), it generally doesn't really pay off to automatically parallelize on branches. You get minimal speedups (1% at best). > > I tend to agree with Stefan / Michael / Guy Steele... Maybe you don't need much, but the mapreduce style is the minimum requirement to give the language enough "wiggle room" to automatically parallelize stuff. But it DOES require you to restructure your application in a slightly more declarative fashion. > > cheers, > Toon > > On 04/29/2011 04:55 PM, Alexandre Bergel wrote: >> Hi Stefan, >> >> I though about your email. I do not understand why automatic parallelization is not the way to go. In my opinion, the computer has much more knowledge about the programmer about where side effects appear and where to cut or split a computation. >> >> Actually, if I want to be provocative, I would say that parallelization cannot be effective without being automatic. For a similar reason that the compiler will always know better than me how to properly allocate registers. >> >> I feel it would be cheaper for me to buy a faster computer than to learn how to program in a multi-core fashion. >> >> Cheers, >> Alexandre >> >> >>>> However, as I understand it, it's entirely up to user to write code >>>> exploiting parallel Process explicitly right ? >>> Sure, you have to do: n times: [ [ 1 expensiveComputation. ] fork ]. >>> >>> I don't belief in holy grails or silver bullets. >>> Automatic parallelization is something nice for the kids, like Santa Clause or the Easter Bunny... >> >> > > -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

April 29, 2011

Re: [Pharo-project] Counting Messages as a Proxy for Average Execution Time in Pharo

by Alexandre Bergel

Hi Stefan, I though about your email. I do not understand why automatic parallelization is not the way to go. In my opinion, the computer has much more knowledge about the programmer about where side effects appear and where to cut or split a computation. Actually, if I want to be provocative, I would say that parallelization cannot be effective without being automatic. For a similar reason that the compiler will always know better than me how to properly allocate registers. I feel it would be cheaper for me to buy a faster computer than to learn how to program in a multi-core fashion. Cheers, Alexandre >> However, as I understand it, it's entirely up to user to write code >> exploiting parallel Process explicitly right ? > Sure, you have to do: n times: [ [ 1 expensiveComputation. ] fork ]. > > I don't belief in holy grails or silver bullets. > Automatic parallelization is something nice for the kids, like Santa Clause or the Easter Bunny... -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

April 29, 2011

Re: [Pharo-project] Counting Messages as a Proxy for Average Execution Time in Pharo

by Toon Verwaest

>> You shouldn't write "do" loops that start at the beginning and go until the end. You should just say that you want the calculation done and that your intent is that you have visited everything. And then of course you might have dependencies etc... but the idea is generally, don't say how to do it, just declare what you want as a result. >> >> Of course, it doesn't immediately match what we are used to doing: telling the computer how we want things done; but you can't really say that you have to tell the computer more about parallelization. It's exactly the opposite. > Well, it is not that easy. You have to include enough information intro the program, and you have to break it down in a way that allows parallelism. > For instance, you need to tell the machine that your operators are associative or commutative to enable optimizations and reordering. > And there seem to be approaches for instance to infer parallel solutions like prefix-sum algorithms[1] but that is also restricted to certain applications. Nothing general, no holly grail or silver bullet. > > > Best regards > Stefan Sure sure. I was just avoiding unnecessary details from the talk ;P

April 29, 2011

Re: [Pharo-project] Zinc problems found

by Esteban Lorenzano

Hi Sven, no, it has to have a body (if I use HTTPSocket, I get a correct answer) here is a script that can show you the problem: | response auth | response := ZnClient post: 'http://127.0.0.1:333/accounts/ClientLogin' data: (ZnApplicationFormUrlEncodedEntity withAll: (Dictionary new at: 'Email' put: 'YOUR GOOGLE ACCOUNT'; at: 'Passwd' put: 'YOUR SECRET PASSWORD'; at: 'service' put: 'analytics'; yourself)). auth := Dictionary new. (response entity contents subStrings: Character lf asString) do: [ :each | (each subStrings: '=') in: [ :array | auth at: array first put: array second ] ]. ZnHTTPSocketFacade httpGetDocument: 'http://127.0.0.1:333/analytics/feeds/accounts/default' args: nil accept: '*/*' request: ('Authorization: GoogleLogin Auth={1}{2}' format: {auth at: 'Auth'. String crlf}). (if you replace ZnHTTPSocketFacade with HTTPSocket, you get a correct answer, if you have a google analytics account) btw... 127.0.0.1:333 is a stunnel who redirects to https://google.com Cheers, Esteban El 29/04/2011, a las 2:32a.m., Sven Van Caekenberghe escribiÃ³: > Hello Esteban, > > On 29 Apr 2011, at 00:26, Esteban Lorenzano wrote: > > Thanks for reporting these issues, I'll have a look at them, but during the day I am out of the office and have meetings, so it won't be until the evening that I have some time, maybe only tomorrow. > > I remember having thought about the first issue, I just don't remember why I did it that way, I'll have to check a bit. > > The second issue them, can you send a print string of the headers in that response ? Maybe there just is no body ? Is there a way for me to try that request ? > > Sven > >> Hi, >> I found some problems on Zinc implementation. >> >> Take this example: >> >> HTTPSocket >> httpGetDocument: 'http://127.0.0.1:333/analytics/feeds/accounts/default' >> args: (Dictionary new >> at: 'prettyprint' put: #('true'); >> yourself) >> accept: '*/*' >> request: ('Authorization: GoogleLogin Auth={1}{2}' format: {self authenticationKey. String crlf} >> >> this, if I have the correct authentication key, gives me the correct answer (an atom-xml response). >> >> Now, if I try: >> >> ZnHTTPSocketFacade >> httpGetDocument: 'http://127.0.0.1:333/analytics/feeds/accounts/default' >> args: (Dictionary new >> at: 'prettyprint' put: #('true'); >> yourself) >> accept: '*/*' >> request: ('Authorization: GoogleLogin Auth={1}{2}' format: {self authenticationKey. String crlf} >> >> (this should work, as the facade is for compatibility, I think) >> >> I have two errors, one of them easily solvable, and the other... well... I couldn't solve it in the 15' I spent on it :) >> >> 1) arguments are not in the correct way. While HTTPSocket functions expect something like this: >> >> Dictionary new >> at: 'prettyprint' put: #('true'); "<-- Parameter is an array" >> yourself. >> >> ZnHTTPSocketFacade expects something like this: >> >> Dictionary new >> at: 'prettyprint' put: 'true'; "<-- Parameter is a string" >> yourself. >> >> 2) This is the hard one. If you do the get request with parameter fixed, you should get the atom feed. >> But you don't. >> You get a ZnResponse who is OK (status 200), but entity is empty. I followed the error until this method: >> >> canReadContent >> ^ self hasContentLength or: [ self isChunked or: [ self allowsReadingUpToEnd ] ] >> >> who return false, because none of the questions is true. Then, no entity is filled, and I have no answer :( >> >> Hope this help :) >> >> Cheers, >> Esteban >> >> >> >> >> >> >> >> >> > >

April 29, 2011