Self-interest April 1999

self-interest@lists.selflanguage.org

12 participants
13 discussions

Re: Self on Linux
by Gordon Cichon 10 Sep '99

10 Sep '99

Hi, my vacation is over, I have to continue working on something else. Therfore I have less time now to continue with the Self port. I think that there is not missing too much to finally get a running system (with all the applications :-)). It all comes down to the stack walking code. In order to give others the chance to participate, too, I have put the stuff on the web server. Everybody who likes to see Self on Linux as soon as possible, and knows how to use a debugger is invited to help fixing the remaining problems. I will continue, too, of course. Maybe, I also made some mistakes... http://www.cichon.de/self/ -gordon -- ---------------------------------------------------- Gordon Cichon email: Gordon(a)Cichon.de ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/list/self-interest Free Web-based e-mail groups by eGroups.com

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desnarfing tinySelf
by Jecel Assumpcao Jr 28 Apr '99

28 Apr '99

The number one complaint by far that people have about Self is that it doesn't run on their machines. So it isn't surprising that the question I get asked most often is how do I intend to address the portability problem. Paul Wilson calls "snarfing" (in his excellent pages about implementing scheme - check out http://www.cs.utexas.edu/users/oops/ ) the act of implementing a feature in a language by simply stealing it from the underlying system. You could, for example, implement recursion in a Logo written in C by creating a stack array and having an explicit stack pointer that must be carefully kept updated. Or you could simply *snarf* the recursion already available in C. Snarfing makes it much easier to get started by reducing the number of things you have to worry about to obtain a working system. But it creates a tight dependence between the implementing and implemented systems, greatly reducing portability. And in the case of bootstrapping (such as tinySelf on Self 4.0 or a Lisp written in Lisp) it becomes an obstacle to be removed before the system can run "stand alone". TinySelf 1 was written in Self 4.0 back in 1997 as a quick and dirty test to see if parallel execution of Self programs was possible. I haven't finished debugging it yet and it was never intended to be the base for something better - tinySelf 2 is to be written from scratch instead. Even so, looking at what tinySelf 1 snarfs from the underlying Self 4 helps give us a sense of what must be done next: - the whole memory system. There is no separation between tinySelf 1 objects and Self objects. So tinySelf doesn't have to worry about allocation, garbage collection, it has no notion of maps and uses mirrors to access slots and things. The need to create mirrors for every object it uses is the main performance problem in this implementation. - all the primitives except '_Restart'. TinySelf would just do a "perform: primitiveSelector" in Self to get things done except the Self VM doesn't like that. So each primitive is wrapped in a trivial method and tinySelf asks Self to "perform" that instead. - the parser. When you give tinySelf an expression to evaluate, it uses Self to parse that into an object, which is then available at the tinySelf level due to the shared memory system. So if tinySelf 2 is to run on systems other than Self 4, the first thing it must do is implement the above things itself and not snarf them. A second portability problem is that there are too many primitives making Self 4's interface to the system on which it runs "too wide". The UI is the best example - while Self exposes all of the X Window API in the form of dozens of primitives, Squeak only requires a primitive to copy a bitmap from an internal form object to the frame buffer in order to work. Porting Squeak involves only writing a simple piece of code, while making Self run on Win32 or the Mac would involve adding a layer to essentially emulate X Windows on them (though such layers are available, so it might not be that much work). So one thing that would improve portability would be to "narrow down" the interface to the implementation platform by reducing the number of primitives. Unlike Squeak, Self doesn't not have a performance problem of things implemented using the language instead of primitives. After considering several options, I decided on an alternative for tinySelf 2 which isn't minimal but which should make it easier for other people to port it to various platforms. The main objects involved are: - compiler. This object takes bytecodes and using the current cpuDescription object is generates machine language code. More than one variation can exist, such as the current NIC and SIC. - cpuDescription. This encapsulates all the characteristics of a given cpu (X86, PowerPC, Sparc, ARM, Trimedia, etc.) so the other objects can be more portable. The level of detail here can be as high as needed - the X86 object can later be complemented with 486, Pentium, K6, MII, PentiumPro and so on objects. This will boost performance as the compiler will be able to tune the instruction scheduling to the actual hardware. - platformDescription. This encapsulates the "drivers" part of the system. Some platforms are Win32, POSIX and BarePC. This is the only place in the system where non Self code, assembly language, in this case, is allowed. These tend to be abstract objects - when combined with a cpuDescription object they form a concrete combo called a host object. - emulator. Given a host object, it can "run" code written for that host. - umbilical. This object connects two executions of Self: the motherSelf and the babySelf. They might run on separate machines connected by a LAN or serial port, as two processes in a native OS connected by that OS's IPC or the babySelf might run in the emulator running inside the motherSelf. Whatever the case, this object allows motherSelf to have complete control of babySelf and includes a protocol to allow objects to flow back and forth between them. - reflectiveVM. This includes memory allocation, garbage collection, multithreading, message passing, etc. all written in Self. So the first step is to get all this (except for the reflectiveVM) running in Self 4.0. A host object containing the X86 cpuDescription and the POSIX platformDescription must be created and the emulator is started up. The compiler, running in Self 4, gets to work on the umbilical object and the resulting X86 code is used to "boot" the emulator. Then the compiler generates code for the reflectiveVM and the compiler itself and sends it over the umbilical to the tinySelf 2 running inside the emulator. At some point this tinySelf is complete enough that saving a snapshot should result in a file that can actually run by itself on an Intel Linux machine! Note that the emulator isn't strictly necessary. The previous steps could have been done by connecting the umbilical to an actual Intel Linux machine instead. But doing it via an emulator is much more convenient since you can single step, examine memory, etc. Having two paths to babySelf (the umbilical object and the emulator's UI) makes it much easier to see what is going on. Of course, if the emulator isn't accurate then things will crash when trying it out on the actual hardware. But these bugs will be eliminated in time and it will become easier and easier to do new ports. It is interesting to compare this with the Squeak approach. They need an external system (the C compiler) to avoid having to deal with different CPUs. The problem is that this external system is only available when generating an new VM, not at runtime like the compiler described here. They moved most platform stuff into "black boxes" - some hand written C files. In contrast, the system I proposed is totally self contained (like many Forths) and takes full advantage of the power of Self (like multiple inheritance, polymorphism...). I still have a few things to do before I start working on this, but it is my hope that someday you will have tinySelf coming soon to a computer near you. -- Jecel ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/list/self-interest Free Web-based e-mail groups by eGroups.com

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Please send me any Self links...
by Randall.Smith＠Eng.Sun.COM 23 Apr '99

23 Apr '99

I am going to update the Self web pages here at Sun, and would like to have links to all current and relevant Self work. If you are doing or even know of some Self-related project, please send me a URL if you have one. Even send me the obvious ones I should know about, I would consider it a favor to have it show up in my mail rather than to have to do the virtual archeology necessary to unearth the info from my jumbled files or my own brain... You can reply directly to me randall.smith(a)sun.com Thanks! --Randy ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/group/self-interest http://www.eGroups.com - Simplifying group communications

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Re: Self on Solaris 2.6?
by Jecel Assumpcao Jr 23 Apr '99

23 Apr '99

I use Self on SunOS 5.6/Solaris 2.6 and the only problem I had was when you selected some text there would be a primitive fail as it tried to copy your selection to the X Window clipboard. The following patch eliminates the nasty notifiers by not calling the primitive anymore: http://www.lsi.usp.br/~jecel/release/patches/xlibPatch.self -- Jecel ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/group/self-interest http://www.eGroups.com - Simplifying group communications

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Re: Self on Solaris 2.6?
by Douglas Atique 23 Apr '99

23 Apr '99

Hello Mathias, I have installed Self 4.0 on a Sun SPARCstation2 that runs Solaris 2.6 and it seemed to run OK. Unfortunately, I had to uninstall it very quickly, as I hadn´t the necessary permission to use the disk space (nor the CPU cycles) and I don´t know if there is something wrong. But I know it will start. Install it and try it, too, it is worth. If you find something wrong, please tell me. I´m interested in it. Regards, Douglas ifw98041(a)informatik.fh-muenchen.de wrote: > Content-Type: text/plain > Subject: Self on Solaris 2.6? > X-Mailer: www.eGroups.com Message Poster > MIME-Version: 1.0 > Message-ID: <pid26626.1999.April.23.4:08.83524.@egroups.com> > Content-Type: text/plain > Date: Fri, 23 Apr 1999 11:08:29 -0000 > In-Reply-To: > From: ifw98041(a)informatik.fh-muenchen.de > To: self-interest(a)egroups.com > > Hello, > For preparing a small lecture in a course on conecpts of modern programming languages I am participating, I would like to play a bit with the Self4.0 system. On the Release Download Webpage it says, Self would run with Solaris 2.3 and 2.4. > My question now is, if it would run under v2.6 of Solaris, too, since this seems to be the OS version all of our SUN workstations are runnig with here at FH Muenchen (University of Applied Sciences Munich) > Has anybody tried it on 2.6? > > Thanks in advance > Mathias > > ------------------------------------------------------------------------ > V-Tech Computer For Kids! Challenge your kids with activities in math, > trivia, vocabulary, spelling, grammer! Looks just like your PC! No- > Hassle Returns*Satisfaction Guaranteed*Only $90.00 Free Freight in US > http://clickhere.egroups.com/click/144 > > eGroup home: http://www.eGroups.com/group/self-interest > http://www.eGroups.com - Simplifying group communications ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/group/self-interest http://www.eGroups.com - Simplifying group communications

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Self on Solaris 2.6?
by ifw98041＠informatik.fh-muenchen.de 23 Apr '99

23 Apr '99

Hello, For preparing a small lecture in a course on conecpts of modern programming languages I am participating, I would like to play a bit with the Self4.0 system. On the Release Download Webpage it says, Self would run with Solaris 2.3 and 2.4. My question now is, if it would run under v2.6 of Solaris, too, since this seems to be the OS version all of our SUN workstations are runnig with here at FH Muenchen (University of Applied Sciences Munich) Has anybody tried it on 2.6? Thanks in advance Mathias ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/group/self-interest http://www.eGroups.com - Simplifying group communications

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Re: Still Self on Linux.
by Jecel Assumpcao Jr 23 Apr '99

23 Apr '99

ian(a)monk.cgocable.ca wrote: > > Well, I have nothing else to ask if any (let's say, Gordon's one) Self for Linux is no available. It's quite shame to not having Self on Linux. Why Self creator didn't had in mind portability.. just like Squeak (pretty neat) ? I would guess that working for Sun made the Self team see things a little differently than most of us regarding which machines were the most "interesting". Squeak is very portable, but that has a great cost in terms of performance. The only way you can have portability is by ignoring the special characteristics of all the different machines. But the way to make things fast is by taking all these special features into account. I am looking at Ian Piumarta's new Jitter 2 compiler for Squeak and it is very interesting. It tries to improve performance without hurting portability. That is a noble goal, and I described in previous email to this list my own ideas about how to get there. -- Jecel ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/group/self-interest http://www.eGroups.com - Simplifying group communications

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Still Self on Linux.
by ian＠monk.cgocable.ca 22 Apr '99

22 Apr '99

Well, I have nothing else to ask if any (let's say, Gordon's one) Self for Linux is no available. It's quite shame to not having Self on Linux. Why Self creator didn't had in mind portability.. just like Squeak (pretty neat) ? Ian ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/group/self-interest http://www.eGroups.com - Simplifying group communications

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No Subject
by jbgarcia＠pi.seinv.uvigo.es 18 Apr '99

18 Apr '99

Hi again. ;-) No, Gordon, I can't do the next step. By doing 'make lists' in ../linux/generated, I got the output: cwdROOT*, no such file or directory makeList*, no such file or directory make: error 127 make: error 1 But these programs really are there, in self/bin/shell and in self/vm....(I don't remember exactly where). I tried to execute the make with the programs copied into the directory, but it didn't work. What's the trouble now ? I've tried also all the rest of the steps, and it didn't work none of them. Regards, jose ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/list/self-interest Free Web-based e-mail groups by eGroups.com

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Re: No Subject
by Jose' B. Garcia Perez-Schofield 17 Apr '99

17 Apr '99

> All: > > Do I understand this correctly: Is Self 4 available on Linux? > > > Well.. I am attemping to install Self for Linux, yes, but it is a limited version, it isn't (I think) the complete 4 version. (If you are interested in the graphic world, I'm afraid that it is not released yet.) Visit the page of the author, Gordon Cichon, where I donwloaded the software: www.cichon.de/self There are a lot of explanations into this page. Regards, jose ------------------------------------------------------------------------ eGroup home: http://www.eGroups.com/list/self-interest Free Web-based e-mail groups by eGroups.com

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Self-interest April 1999