- Pharo-dev - lists.pharo.org

mutex optimisation - #ifTrue:ifFalse versus #ifNil:ifNotNil:

by Ben Coman

The Mutex primitives return a tri-state value: true, false and nil. So we would have... NewMutex>>critical: mutuallyExcludedBlock ifLocked: alternativeBlock ^lock tryAcquire ifNil: mutuallyExcludedBlock ifNotNil: [:acquired| acquired ifTrue: [mutuallyExcludedBlock ensure: [lock strictRelease]] ifFalse: alternativeBlock ]. NewMutex>>critical: mutuallyExcludedBlock ^lock waitAcquire ifNil: mutuallyExcludedBlock ifNotNil:[ mutuallyExcludedBlock ensure: [lock strictRelease] ]. So we would have NewMutex>>critical: aBlock ifLocked: lockedBlock ^lock tryAcquire ifNil: mutuallyExcludedBlock ifNotNil: [:acquired | acquired ifTrue: [mutuallyExcludedBlock ensure: [lock strictRelease]] ifFalse: alternativeBlock ]. Mutex>>critical: aBlock ifLocked: lockedBlock ^self primitiveTestAndSetOwnershipOfCriticalSection ifNil: [lockedBlock value] ifNotNil:[:alreadyOwner| alreadyOwner ifTrue: [aBlock value] ifFalse: [aBlock ensure: [self primitiveExitCriticalSection]]] ifNil:ifNotNil: Also, I notice several of RBMessageNode>>isInlineXXXX methods contain... self receiver isBlock ifTrue: [^ false]. Does this mean that... [ true ] ifTrue: [2] ifFalse: [3] is not inlined?

Feb. 19, 2016

FFI related musings

by Ben Coman

While musing on FFI interfacing issues like C++ name mangling, I found an interesting article "Beautiful Native Libraries" about the other side of the fence of designing a nice library interface. I learnt some things maybe of interest to others - perhaps for pushing upstream into external libraries to ease their use by our FFI. http://lucumr.pocoo.org/2013/8/18/beautiful-native-libraries/ Some of the ideas seem applicable to maybe one day helping the VM be embeddable in other programs. Also, for the occasional idea of in-Image parsing of C include files, a link to a basic algorithm for macro expansion. http://www.spinellis.gr/blog/20060626/ And while I haven't read the following, it was interesting to skim "Calling conventions for different C++ compilers and operating systems" http://www.agner.org/optimize/calling_conventions.pdf cheers -ben

Feb. 19, 2016

Re: [Pharo-dev] [squeak-dev] Process>>isSusended

by David T. Lewis

On Thu, Feb 18, 2016 at 10:03:47PM -0500, David T. Lewis wrote: > On Thu, Feb 18, 2016 at 01:22:28PM -0800, Eliot Miranda wrote: > > Hi All, > > > > we have a serious misunderstanding in current versions of Squeak's and > > Pharo's Process>>isSuspended. > > > > Squeak's version reads > > > > isSuspended > > ^myList isNil > > > > Pharo's reads > > > > isSuspended > > ^myList isNil or: [ myList isEmpty ] > > > > Process's myList holds the list a process is on when it is not running. > > There is only one running process at any one time, Processor > > activeProcess. The active process's myList is always nil, so Squeak's and > > Pharo's are both wrong for the active process. > > > > Processor activeProcess isSuspended => true (!!!) > > This was working correctly as of Squeak4.6, but not in Squeak5.0.15113.image. Correcting myself, the difference in behavior is related to the VM. Using a Squeak 4.6 image and comparing Cog versus interpreter VM: Processor activeProcess isSuspended ==> true "Cog" Processor activeProcess isSuspended ==> false "interpreter VM" I think there were some process scheduling improvements introduced in Cog, and maybe the image needs to be adjusted accordingly? Dave

Feb. 19, 2016

Re: [Pharo-dev] [squeak-dev] Process>>isSusended

by David T. Lewis

On Thu, Feb 18, 2016 at 01:22:28PM -0800, Eliot Miranda wrote: > Hi All, > > we have a serious misunderstanding in current versions of Squeak's and > Pharo's Process>>isSuspended. > > Squeak's version reads > > isSuspended > ^myList isNil > > Pharo's reads > > isSuspended > ^myList isNil or: [ myList isEmpty ] > > Process's myList holds the list a process is on when it is not running. > There is only one running process at any one time, Processor > activeProcess. The active process's myList is always nil, so Squeak's and > Pharo's are both wrong for the active process. > > Processor activeProcess isSuspended => true (!!!) This was working correctly as of Squeak4.6, but not in Squeak5.0.15113.image. Dave

Feb. 19, 2016

Re: [Pharo-dev] [ANN] The Pharo Unicode Project

by Mariano Martinez Peck

Wow guys. Unbelievable. Amazing. Coming from you and Henry, I really don't expect anything else than this :) Sven I also love your midium posts. Thanks!!! On Thu, Feb 18, 2016 at 6:22 PM, stepharo <stepharo(a)free.fr> wrote: > I ***LOVE*** the documentation :) > > > Le 17/2/16 10:16, Sven Van Caekenberghe a Ã©crit : > > Hi, >> >> In Pharo we can deal with and represent any Unicode character and string, >> but there are still some important pieces of functionality missing. >> >> The goal of the Pharo Unicode project is to gradually improve and expand >> Unicode support in Pharo. We started in December last year to lay the >> foundation and are now ready to go public with what we built. >> >> The first delivery is an implementation of Unicode Normalization, >> together with an implementation of the Unicode Character Database. >> >> Please read the following article for more information (the appendix >> explains how to get the code). >> >> An Implementation of Unicode Normalisation >> >> Streaming NFC, NFD, NFKC & NFKD, normalization QC and normalization >> preserving concatenation. >> >> >> https://medium.com/concerning-pharo/an-implementation-of-unicode-normalizat… >> >> The development branch also contains a work in progress implementation of >> Unicode Collation. >> >> Much work remains to be done and contributions are more than welcome. >> >> Sven & Henrik >> >> > > -- Mariano http://marianopeck.wordpress.com

Feb. 19, 2016

Re: [Pharo-dev] [ANN] The Pharo Unicode Project

by stepharo

I deeply appreciate your effort! Le 17/2/16 23:27, Sven Van Caekenberghe a Ã©crit : >> On 17 Feb 2016, at 19:56, Esteban A. Maringolo <emaringolo(a)gmail.com> wrote: >> >> I read the whole Article, seems like a tricky, to not say hard, subject. > Yes. The Unicode specs are big and complex. Step one is to read & understand them, at least well enough to find your way. Doing some implementation is not too hard, but getting 100% scores on the very extensive test suites was/is quite hard. > >> The article is very detailed and well written though. > Thx. > >> What is the rationale behind embracing such a challenging feature like supporting Unicode? > Unicode is the de facto standard for internationalisation of computer software. Any serious platform has to tackle (big parts of) Unicode. > >> Regards! >> >> >> Esteban A. Maringolo >> >> >> 2016-02-17 15:24 GMT-03:00 Max Leske <maxleske(a)gmail.com>: >>> Good stuff guys! >>> >>>> On 17 Feb 2016, at 10:16, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >>>> >>>> Hi, >>>> >>>> In Pharo we can deal with and represent any Unicode character and string, but there are still some important pieces of functionality missing. >>>> >>>> The goal of the Pharo Unicode project is to gradually improve and expand Unicode support in Pharo. We started in December last year to lay the foundation and are now ready to go public with what we built. >>>> >>>> The first delivery is an implementation of Unicode Normalization, together with an implementation of the Unicode Character Database. >>>> >>>> Please read the following article for more information (the appendix explains how to get the code). >>>> >>>> An Implementation of Unicode Normalisation >>>> >>>> Streaming NFC, NFD, NFKC & NFKD, normalization QC and normalization preserving concatenation. >>>> >>>> https://medium.com/concerning-pharo/an-implementation-of-unicode-normalizat… >>>> >>>> The development branch also contains a work in progress implementation of Unicode Collation. >>>> >>>> Much work remains to be done and contributions are more than welcome. >>>> >>>> Sven & Henrik >>> > >

Feb. 18, 2016

Process>>isSusended

by Eliot Miranda

Hi All, we have a serious misunderstanding in current versions of Squeak's and Pharo's Process>>isSuspended. Squeak's version reads isSuspended ^myList isNil Pharo's reads isSuspended ^myList isNil or: [ myList isEmpty ] Process's myList holds the list a process is on when it is not running. There is only one running process at any one time, Processor activeProcess. The active process's myList is always nil, so Squeak's and Pharo's are both wrong for the active process. Processor activeProcess isSuspended => true (!!!) A process may be runnable, but not running (which follows form there being only one running process, the active process, at any one time). If it is runnable but not running its list is one of the runnable process lists in the scheduler, e.g. Processor waitingProcessesAt: Processor activePriority => a LinkedList() Processor waitingProcessesAt: Processor lowestPriority => a LinkedList(a Process in ProcessorScheduler class>>idleProcess) Here's a couple of illustrative examples: [Semaphore new wait] fork suspendingList => a LinkedList(a Process in [] in BlockClosure>>newProcess) ([Semaphore new wait] forkAt: Processor activePriority + 1) suspendingList => a Semaphore(a Process in [] in UndefinedObject>>DoIt) In the first example above the new process isn't running yet. It's runnable but hasn't got a chance to run because the active process that created it is still running. So the process's list is Processor waitingProcessesAt: Processor activePriority. In the second example the process has got to run, because, having higher priority, it has preempted the active process that created it. So it suspends waiting on the semaphore. So in fact, isSuspended should read something like isSuspended | myRunList | myRunList := Processor waitingProcessesAt: priority. ^myList notNil and: [myList ~~ myRunList] except that this isn't atomic. But it isn't the complete nonsense we have at the moment. Here's an atomic version that answers the truth at the point that the question was asked: isSuspended | myPriority | myPriority := priority. ^myList ifNil: [false] ifNotNil: [:list| list ~~ (Processor waitingProcessesAt: myPriority)] We need tests like self deny: Processor activeProcess isSuspended. self deny: ([Semaphore new wait] forkAt: Processor activePriority) isSuspended. self assert: ([Semaphore new wait] forkAt: Processor activePriority + 1) isSuspended. _,,,^..^,,,_ best, Eliot

Feb. 18, 2016

Re: [Pharo-dev] [ANN] The Pharo Unicode Project

by stepharo

I ***LOVE*** the documentation :) Le 17/2/16 10:16, Sven Van Caekenberghe a Ã©crit : > Hi, > > In Pharo we can deal with and represent any Unicode character and string, but there are still some important pieces of functionality missing. > > The goal of the Pharo Unicode project is to gradually improve and expand Unicode support in Pharo. We started in December last year to lay the foundation and are now ready to go public with what we built. > > The first delivery is an implementation of Unicode Normalization, together with an implementation of the Unicode Character Database. > > Please read the following article for more information (the appendix explains how to get the code). > > An Implementation of Unicode Normalisation > > Streaming NFC, NFD, NFKC & NFKD, normalization QC and normalization preserving concatenation. > > https://medium.com/concerning-pharo/an-implementation-of-unicode-normalizat… > > The development branch also contains a work in progress implementation of Unicode Collation. > > Much work remains to be done and contributions are more than welcome. > > Sven & Henrik >

Feb. 18, 2016

Re: [Pharo-dev] [ANN] The Pharo Unicode Project

by stepharo

Super cool! Stef Le 17/2/16 10:16, Sven Van Caekenberghe a Ã©crit : > Hi, > > In Pharo we can deal with and represent any Unicode character and string, but there are still some important pieces of functionality missing. > > The goal of the Pharo Unicode project is to gradually improve and expand Unicode support in Pharo. We started in December last year to lay the foundation and are now ready to go public with what we built. > > The first delivery is an implementation of Unicode Normalization, together with an implementation of the Unicode Character Database. > > Please read the following article for more information (the appendix explains how to get the code). > > An Implementation of Unicode Normalisation > > Streaming NFC, NFD, NFKC & NFKD, normalization QC and normalization preserving concatenation. > > https://medium.com/concerning-pharo/an-implementation-of-unicode-normalizat… > > The development branch also contains a work in progress implementation of Unicode Collation. > > Much work remains to be done and contributions are more than welcome. > > Sven & Henrik >

Feb. 18, 2016

Re: [Pharo-dev] [ANN] The Pharo Unicode Project

by Sven Van Caekenberghe

Here is a quick & dirty version without error checking: | codePoint ucd name hex url | codePoint := 180. codePoint := 8491. ucd := codePoint unicodeCharacterData. name := $_ join: (Character space split: ucd name asLowercase). hex := String streamContents: [ :out | codePoint printOn: out base: 16 nDigits: 4 ]. url := 'http://www.fileformat.info/info/unicode/char/{1}/{2}.png' format: { hex. name }. ZnEasy getPng: url. They seem to be adding a watermark if you do it like this, but not all the time. > On 18 Feb 2016, at 20:24, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > >> >> On 18 Feb 2016, at 18:13, Ben Coman <btc(a)openinworld.com> wrote: >> >> On Thu, Feb 18, 2016 at 10:52 PM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >>> Ben, >>> >>>> On 18 Feb 2016, at 02:05, Ben Coman <btc(a)openInWorld.com> wrote: >>>> >>>> On Wed, Feb 17, 2016 at 5:16 PM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >>>>> Hi, >>>>> >>>>> In Pharo we can deal with and represent any Unicode character and string, but there are still some important pieces of functionality missing. >>>>> >>>>> The goal of the Pharo Unicode project is to gradually improve and expand Unicode support in Pharo. We started in December last year to lay the foundation and are now ready to go public with what we built. >>>>> >>>>> The first delivery is an implementation of Unicode Normalization, together with an implementation of the Unicode Character Database. >>>>> >>>>> Please read the following article for more information (the appendix explains how to get the code). >>>>> >>>>> An Implementation of Unicode Normalisation >>>>> >>>>> Streaming NFC, NFD, NFKC & NFKD, normalization QC and normalization preserving concatenation. >>>>> >>>>> https://medium.com/concerning-pharo/an-implementation-of-unicode-normalizat… >>>>> >>>>> The development branch also contains a work in progress implementation of Unicode Collation. >>>>> >>>>> Much work remains to be done and contributions are more than welcome. >>>>> >>>>> Sven & Henrik >>>> >>>> This is really great. Thanks Sven & Henrik. >>> >>> You're welcome. >>> >>>>> The right pane shows a large glyph view of the character involved. >>>> >>>> This is very cool !! >>>> Does it rely on font support, or is it bitmap or SVG based? >>> >>> Currently, we just use what Pharo can do (it thus depends on your font and even then the layout is often wrong in special cases, something we need to fix as well). >>> >>>> Maybe it could dynamically download SVG data as needed from somewhere >>>> like here... >>>> http://www.fileformat.info/info/unicode/char/00f6/index.htm >>> >>> Wow, I was looking for something like that, but I didn't know it existed. >>> >>> Can we somehow directly use SVG in Pharo ? >>> >>> On this page [http://www.fileformat.info/info/unicode/index.htm] they say that they got all their info from unicode.org but I can't seem to find the SVG data there. You seem to be good in finding stuff ;-) >> >> aH-Har! A challenge! but I did not succeed. > > I thought you would write a complete solution in Pharo, oh well ;-) > >> The Unicode Code Charts >> [1] seem available only in PDF form (e.g. [2]) . Indeed it says "The >> fonts and font data used in production of the Unicode Standard may not >> be extracted, or used in any way in any product or publication, >> without permission or license granted by the typeface owner(s)." >> >> [1] http://unicode.org/charts/About.html >> [2] http://unicode.org/charts/PDF/U0100.pdf >> >> Though I discovered a few other interesting resources... >> >> Fallback font >> https://en.wikipedia.org/wiki/Fallback_font >> >> Last Resort Font >> http://www.unicode.org/policies/lastresortfont_eula.html >> >> Scriptsource - Unicode Character Browsing >> http://scriptsource.org/cms/scripts/page.php?item_id=entry_detail&uid=tubkv… >> >> Javascript Unibook 4.0 Character Browser >> http://www.soldin.de/about/2003-js_unibook/ >> >> decodeunicode >> http://www.decodeunicode.org/ > > Yeah, good links. > > This site seems to be able to generate .png's for each glyph > > http://r12a.github.io/uniview/ > > Though the URLs are not straightforward and probably not meant to be used as web service. > > Maybe this is usable: > > https://en.wikipedia.org/wiki/GNU_Unifont > >> HTH, cheers -ben >> >>> >>> In any case, it would be very cool to have something like that as a fall back. >>> >>>>> We also added an extension to our environmentâs search system to allow you to look up characters by name: >>>> >>>> Is there a #unicode filter for Spotter? >>> >>> That comes for free. >>> >>>> check repeated phrase... >>>>> and replace it with and replace it with >>> >>> Fixed, thanks. >>> >>>> I bumped into an interesting "Good, Bad, Ugly" comparison of Unicode >>>> support in other programming languages (though circa 2011) >>>> https://www.azabani.com/pages/gbu/ >>> >>> Reading it. >>> >>>> and this sparked a thought to wonder if the consortium would consider >>>> it worthwhile paying someone external (like that author) with broad >>>> cross platform Unicode experience to consult on getting Pharo to a >>>> pragmatic point where we look attractive in such comparisons, which >>>> may also provide a side-channel advertisement for Pharo when such >>>> comparisons are presented at conferences (??) >>> >>> Maybe, I don't know if we should spent (marketing) money like that, but who knows. >>> >>>> cheers -ben >>> >>> Sven

Feb. 18, 2016