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

[Pharo-project] [ANN] Amazon AWS S3 Client

by Sven Van Caekenberghe

Hi All, I implemented and published a Pharo client for Amazon's AWS S3 service called ZnAWSS3Client. For some background, see http://en.wikipedia.org/wiki/Amazon_S3 or http://aws.amazon.com/s3. The code can be found in the package 'Zinc-AWS' in http://www.squeaksource.com/ZincHTTPComponents.html. It depends on both Zinc HTTP Components and XML Support (an excellent package BTW) as well as on the cryptography functionality in Pharo (md5, sha1 & hmac). Basically, Amazon S3 (Simple Storage Service) is an online storage web service where you store and retrieve objects under keys organized in groups called buckets. Objects can be any web resource identified by a mime type. The main advantage is that S3 is a highly scalable, reliable, secure, fast, inexpensive service. The client is currently a proof of concept implementing the basic S3 concepts. Here is some example usage: | client | (client := ZnAWSS3Client new) accessKeyId: '2ZGSSBGBHQGJ9VV5N441'; secretAccessKey: 'OtxrzxIsfpFjA7SwPzILwy8Bw21TLhquhboDYROV'; checkIntegrity: true. client buckets. client keysIn: 'my-bucket'. client keysIn: 'my-bucket' query: (Dictionary with: 'prefix'->'my-'). client at: 'my-bucket' -> 'my-key'. client at: 'my-bucket' -> 'my-key' put: (ZnEntity with: '0123456789'). client at: 'my-bucket' -> 'my-key' put: (ZnEntity with: 'Smalltalk rules S3!') headers: (Dictionary with: 'x-amz-acl'->'public-read'). Sven PS: the code does contain comments but you will need to read up on S3 first. To run anything you will have to create an AWS S3 account.

Jan. 5, 2011

Re: [Pharo-project] Best way for change a window style

by nullPointer

Mi inglÃ©s es penoso. Lo que quiero decir es que aunque haya un proyecto en SourceSafe llamado UIBuilder, que es exactamente igual al CLFramework, lo Ãºnico que he modificado son clases que no tienen nada que ver con aquellas categorÃas relacionadas con el diseÃ±ador de UIs. El desarrollo del diseÃ±ador de interfaces esta cerrado desde hace tiempo y yo al menos no lo voy a continuar. Google translation - My English is poor. What I mean is that even if a project called UIBuilder SourceSafe, which is exactly equal to CLFramework only thing I changed are classes that have nothing to do with those categories related to the designer of UIs. The development of the interface designer is closed for some time and I for one am not going to continue. -- View this message in context: http://forum.world.st/Best-way-for-change-a-window-style-tp3032341p3176337.… Sent from the Pharo Smalltalk mailing list archive at Nabble.com.

Jan. 5, 2011

Re: [Pharo-project] Best way for change a window style

by Hilaire Fernandes

Le 05/01/2011 18:19, nullPointer a Ã©crit : > > CLFramework continues in develop but donÂ´t the subset UIBuilder. For the > change of window styles I didnÂ´t almost update UIBuilder. > > Regards. I don't understand. Hilaire

Jan. 5, 2011

Re: [Pharo-project] Alien and callbacks from "foreign" threads?

by Igor Stasenko

On 5 January 2011 20:07, Eliot Miranda <eliot.miranda(a)gmail.com> wrote: > > > On Wed, Jan 5, 2011 at 10:36 AM, Igor Stasenko <siguctua(a)gmail.com> wrote: >> >> I think any interoperability should have a reasonable limitations. >> Otherwise, there is no way how to guarantee the system stability. >> >> Squeak and Cog virtual machines can't run multiple native threads >> interpreting smalltalk code, which means that >> any callback(s) will be forced to be handled in single (VM) thread. > > No. Â One can arrange to shae the VM between native threads just like Python, > which is what I've done in my prototype. > i didn't said it can't, i just don't see a reason for doing that. Too much for it. >> >> Apparently callbacks from foreign threads require a special checks to >> be added to detect it and then serialize the call to vm thread. > > No. Â One can arrange for the current thread to cede ownership to the foreign > thread and allow it to run. Â With a two-evel scheduler one can still arrange > to preserve Smalltalk process priorities and scheduling semantics. > Â Essentially one assigns a priority to foreign callbacks and they get to run > as soon as their priority is high enough to displace the priority of the > current process (in whatever thread it may be). > The scheme you're describing is one I implemented in VisualWorks and it is > slow and clumsy. Â The scheme I'm now using is due to David Simmons and by > comparison is lightweight and fast. Â But neither are simple. > Sharing VM among multiple threads.. Okay.. but this is same. It doesn't eliminates a need of synchronizing with thread which currently 'owns' VM to obtain a control, which means you can't start handling callback immediately, that's why i told that it kills an idea of using multithreading. Again, i hope you realizing that there is a lot of situations, where this won't go. Suppose that i using some library which using a thread-local storage. How i could guarantee that all calls to this library will be made in same thread, in situation, when VM could run interpreter in any random thread, resulted because of need to handle callback from other library, not related to one that used by code related to my library? I don't see how it can be made 'automagically' without introducing an additional discipline in code, and without any notion of native threads at language side, where developer could enforce some rules, known by him. Otherwise an interoperability scheme which you introducing is mine field. Also, now you must check every single primitive which currently used by VM is thread safe, i.e. it can be invoked from any 'random' thread without leading to unwanted effect(s). Which is a good thing (oh and i did that in Hydra btw). I know very well that some OS(es) and some libraries don't like when you using their functions either from non-main process thread, or from multiple threads. (Btw, Johm told scary story about GUI and multithreading on Macs multiple times ;) ) So, before introducing such kind of sharing , you should take care about every single primitive which using OS-specific function(s) or using some external library, that it is safe to make a calls from random thread. So, the question remains open: is it worth spending so much efforts for such small outcome? :) >> >> And therefore, handling callback in different thread will require a >> synchronization with it, which kills an idea of >> invoking callback from different thread in a first place. > > Nope. > >> >> So, even if Alien will implement support of callbacks in non-VM >> thread(s), the value of such feature are questionable, >> because it simply kills the attempt(s) of foreign language to gain >> performance benefits through exploiting multithreading. > > I disagree. > access to VM run-time are obviosly synchronous. And as long as it true, there is very small reason to use multiple threads. A simple example. Suppose you using a 3rd party library for setting up a socket server, which is a single call, accepting a pointer to function which will handle incoming connections. The external library takes care about rest itself: it using thread pool(s) for incoming connections and in this way distributing load among multiple native threads. Now, what will happen if you pass a smalltalk callback to it? I can elaborate that, but i think you know it yourself. >> >> Allowing to interpret smalltalk using multiple threads is another >> story - see RoarVM :) > > That's not the only way to go. Â Python (and my Cog prototype) shares the VM > amongst native threads and it is quite a lot simpler than implementing a > concurrently-threaded VM. sure its simpler. but kills multithreading benefits :) >> >> So, unless you running RoarVM, i don't see that it is reasonable to >> support cross-thread callbacks. > > Not at all. Â It's quite a reasonable thing to want to do, and is not beyond > us. Yeah, it is painful to turn once non-thread aware VM into be thread aware and play nicely with other players on [mine] field :) > best > Eliot > >> >> -- >> Best regards, >> Igor Stasenko AKA sig. >> > > -- Best regards, Igor Stasenko AKA sig.

Jan. 5, 2011

Re: [Pharo-project] Best way for change a window style

by Mariano Martinez Peck

WHich is the difference between CLFramework and UIBUilder? I thought it was the same.... gracias! mariano On Wed, Jan 5, 2011 at 6:19 PM, nullPointer <epicfan(a)gmail.com> wrote: > > CLFramework continues in develop but donÂ´t the subset UIBuilder. For the > change of window styles I didnÂ´t almost update UIBuilder. > > Regards. > -- > View this message in context: > http://forum.world.st/Best-way-for-change-a-window-style-tp3032341p3175983.… > Sent from the Pharo Smalltalk mailing list archive at Nabble.com. > >

Jan. 5, 2011

Re: [Pharo-project] Alien and callbacks from "foreign" threads?

by Tudor Girba

This is great news! Thanks a lot for your effort, Doru On 5 Jan 2011, at 18:22, Joachim Geidel wrote: > > Hi everybody, > > I am close to releasing JNIPort (http://jniport.wikispaces.com) for Pharo > and Squeak. Almost everything works on both Mac OS X and Windows with one > exception. I can attach a Java VM to Pharo/Squeak, I can send messages to > Java objects and get results back, and even callbacks from Java to Smalltalk > seem to work. > > The exception is that a callback from Java to Smalltalk which comes from a > different thread leads to a crash of the Squeak VM. I have not been able to > figure out what the problem is. There is a similar problem with a hook of > the Java VM: one can register a callback function which is called whenever > the Java VM produces output for stdout/stderr. With Pharo 1.1.1 on Mac OS X, > using this hook works when the hook contains a "nil halt", and if I simply > proceed in each of the notifiers. When I remove the halt or replace it by a > Delay, the image freezes. In Squeak 4.1 on Windows, the behavior is > different: the VM crashes. > > Does Alien support callbacks coming from a "foreign" thread? Or is this a > limitation of Alien? > > Thanks in advance for any help, > Joachim Geidel > > -- > View this message in context: http://forum.world.st/Alien-and-callbacks-from-foreign-threads-tp3175989p31… > Sent from the Pharo Smalltalk mailing list archive at Nabble.com. > -- www.tudorgirba.com "Being happy is a matter of choice."

Jan. 5, 2011

Re: [Pharo-project] Alien and callbacks from "foreign" threads?

by Joachim Geidel

Igor, Igor Stasenko wrote: > > So, unless you running RoarVM, i don't see that it is reasonable to > support cross-thread callbacks. > VisualWorks and Dolphin both support foreign callbacks, using two very different implementations. Yes, it's not easy, as there are lots of ways to create deadlocks and faults etc. Chris Uppal's implementation of JNIPort for Dolphin came with a highly complicated http://metagnostic.dolphinmap.net/JNIPort/threading.html mechanism for deadlock prevention which is now also part of the ports of JNIPort to VisualWorks, Pharo and Squeak. However, there are situations where foreign callbacks are needed simply because the external libraries which are used have a multithreaded implementation. E.g., the callbacks for monitoring a Java VM (to monitor class loading, garbage collection etc.) will always come from a foreign thread, and this has nothing to do with performance. It's just the way it is. Another example (see screenshot at the end of the page): http://metagnostic.dolphinmap.net/JNIPort/callback-example-1.html http://metagnostic.dolphinmap.net/JNIPort/callback-example-1.html Best regards, Joachim Geidel -- View this message in context: http://forum.world.st/Alien-and-callbacks-from-foreign-threads-tp3175989p31… Sent from the Pharo Smalltalk mailing list archive at Nabble.com.

Jan. 5, 2011

Re: [Pharo-project] Alien and callbacks from "foreign" threads?

by Eliot Miranda

On Wed, Jan 5, 2011 at 10:36 AM, Igor Stasenko <siguctua(a)gmail.com> wrote: > I think any interoperability should have a reasonable limitations. > Otherwise, there is no way how to guarantee the system stability. > > Squeak and Cog virtual machines can't run multiple native threads > interpreting smalltalk code, which means that > any callback(s) will be forced to be handled in single (VM) thread. > No. One can arrange to shae the VM between native threads just like Python, which is what I've done in my prototype. > > Apparently callbacks from foreign threads require a special checks to > be added to detect it and then serialize the call to vm thread. > No. One can arrange for the current thread to cede ownership to the foreign thread and allow it to run. With a two-evel scheduler one can still arrange to preserve Smalltalk process priorities and scheduling semantics. Essentially one assigns a priority to foreign callbacks and they get to run as soon as their priority is high enough to displace the priority of the current process (in whatever thread it may be). The scheme you're describing is one I implemented in VisualWorks and it is slow and clumsy. The scheme I'm now using is due to David Simmons and by comparison is lightweight and fast. But neither are simple. > And therefore, handling callback in different thread will require a > synchronization with it, which kills an idea of > invoking callback from different thread in a first place. > Nope. > > So, even if Alien will implement support of callbacks in non-VM > thread(s), the value of such feature are questionable, > because it simply kills the attempt(s) of foreign language to gain > performance benefits through exploiting multithreading. > I disagree. > > Allowing to interpret smalltalk using multiple threads is another > story - see RoarVM :) > That's not the only way to go. Python (and my Cog prototype) shares the VM amongst native threads and it is quite a lot simpler than implementing a concurrently-threaded VM. > So, unless you running RoarVM, i don't see that it is reasonable to > support cross-thread callbacks. > Not at all. It's quite a reasonable thing to want to do, and is not beyond us. best Eliot > > -- > Best regards, > Igor Stasenko AKA sig. > >

Jan. 5, 2011

Re: [Pharo-project] Alien and callbacks from "foreign" threads?

by Joachim Geidel

Eliot Miranda-2 wrote: > > That current version of Alien does /not/ support callbacks from foreign > threads. > Aah, that explains a lot. ;-) Eliot Miranda-2 wrote: > > I have a prototype that does support callbacks from foreign > threasds and supports non-blocking callouts on arbitrary threads. > ... > Are you interested in working with this prototype code? Pleaze let me > know > either way. I haven't sought permission to release this code yet but I > would very much like to. I think there's value to Teleplace in my > releasing > it before we release it internally because it needs pounding on to bring > up > to production quality. If there's significant interest in this code I'll > ask for permission to release it and see where we go from there. > I'm not sure how many people will actually use JNIPort in Pharo or Squeak and need callbacks. Yes, I am interested, but given the small amount of time I have available for JNIPort, it may take some time until I can do something with your prototype. Also, JNIPort is currently just a hobby, and I will not use it in any kind of production software myself. I'm not sure if this qualifies as significant interest. ;-) Thanks! Joachim -- View this message in context: http://forum.world.st/Alien-and-callbacks-from-foreign-threads-tp3175989p31… Sent from the Pharo Smalltalk mailing list archive at Nabble.com.

Jan. 5, 2011

Re: [Pharo-project] Alien and callbacks from "foreign" threads?

by Igor Stasenko

I think any interoperability should have a reasonable limitations. Otherwise, there is no way how to guarantee the system stability. Squeak and Cog virtual machines can't run multiple native threads interpreting smalltalk code, which means that any callback(s) will be forced to be handled in single (VM) thread. Apparently callbacks from foreign threads require a special checks to be added to detect it and then serialize the call to vm thread. And therefore, handling callback in different thread will require a synchronization with it, which kills an idea of invoking callback from different thread in a first place. So, even if Alien will implement support of callbacks in non-VM thread(s), the value of such feature are questionable, because it simply kills the attempt(s) of foreign language to gain performance benefits through exploiting multithreading. Allowing to interpret smalltalk using multiple threads is another story - see RoarVM :) So, unless you running RoarVM, i don't see that it is reasonable to support cross-thread callbacks. -- Best regards, Igor Stasenko AKA sig.

Jan. 5, 2011