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Termite, IO and memory leakage
by Nicholas Walton 30 Nov '08

30 Nov '08

Hi, I have a large Termite based system that runs over eight cores on OS X Leopard. The system distributes itself over as many Termite processes as are made available and each process may make use of anyother. However, I have been getting odd segmentation errors occurring. I have shrunk the code down to the framework built on top of Termite and a small example (as below) (define (stress-test n m) (mapn (lambda(i) (dpmap-split (lambda (i) (length (dpmap-split (lambda(j) (+ j j)) ; (newline) (write j)) (make-integer-list (+ 1 i)) next-slave 'INNER-STRESS (lambda(x)#t))) (thread-sleep! m)) (make-integer-list 100) next-slave 'OUTER-STRESS (lambda(x)#t))) n)) The interface to Termiote is through dpmap-split which acts as a distributed form of map by partitioning the calls from map over the slaved Termite instances, via remote-spawn. Executing (stress-test 1000 0) termintates as expected. I have logging code in dpmap-split which writes to the terminal's for all the processes with no problem. However if I replace the (+ j j) call with (newline) (write j)) then after a while (stress-test 1000 0) fails with a segmentation violation, having until then written to each instance's terminal the values as I would expect. Termite appears to have a problem with IO within spawned processes. Secondly, even with (+ j j) in place it gobbles up core as if there is no tommorrow. By the time (stress-test 10000 0) completes using three instances, each instance has nearly 1Gig allocated. This is causing me considerable problems with the development system that relies on Termite to support its computational requirements and runs for hours at a time making many hundreds of call to Termite via dpmap-split. The interface dpmap-split is side effect free. I have patched Termite's make-tag function to return a string instead of an interned symbol, and traced string->symbol to ensure that interned symbols are not building garbage up, but still Termite devours huge amounts of core. Any ideas please? Nick Walton

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[ANN] Gambit-C v4.3.2 released
by gambit＠iro.umontreal.ca 28 Nov '08

28 Nov '08

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Debugging macros...?
by David St-Hilaire 27 Nov '08

27 Nov '08

Hi all! Is there a way to debug a macro expansion? More precisely, I'd like to be able to have access to the full debugger when my macro expansion fails such that I could trace what's wrong of the code producing the expansion... At the moment I get something like: > (pp (lambda () (define-class tata (toto) (slot: a)))) *** ERROR -- Unbound table key (table-ref '#<table #2> 'tata) > with no possibility to debug and see whats wrong. I guess that the environment is available at the expansion time so I don't see why I couldn't debug it like normal gambit code. Many thanks in advance ^_^Y David

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Thank you for Gambit
by Arthur Smyles 27 Nov '08

27 Nov '08

In the US, our Thanksgiving holiday is coming up. It's a good time to take stock on what to be thankful for. I just wanted to thank all of you for your contributions to the Gambit source code and just as important, the Gambit community. I've really enjoyed programming with it and studying it. I'd also like the thank all the people who contribute questions and answers on this mailing list. I've found them really enlightening at times. Arthur

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Re: [gambit-list] Termite, IO and memory leakage
by Nicholas Walton 27 Nov '08

27 Nov '08

Christian et al, I ran it under gdb having rebuilt gsi / gsc with --debug and without. Little difference in either case. The attached files form the framework with the exception of the SLIB library of utilty functions. The output from gdb is in gdbout.Ran the code compiled and interpreted with no noted difference. Nick On Tuesday, November 25, 2008, at 05:59PM, "Christian Jaeger" <christian(a)pflanze.mine.nu> wrote: >Christian Jaeger wrote: >> Your best bet (short of someone going to debug it for you) really is >> running Gambit under gdb and see where it crashes. Just run "gdb gsc" >> and from there load your program as usual (assuming you're using, or >> know how to use, |compile-file| and |load| for your programs), or "gdb >> yourlinkedprogram" or "gdb gsi-script" or whatever. Then "run >> eventualprogramarguments" then "backtrace" when it crashed. > >PS. I once wrote a script named "with-gdb-backtrace-to" which makes >running apps under gdb trivial, I've now put it up here: > >http://repo.or.cz/w/with-gdb-backtrace-to.git?a=blob_plain;f=with-gdb-backt… >http://repo.or.cz/w/with-gdb-backtrace-to.git > >Christian. > > >

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[ANN] Gambit-C v4.3.1 released
by gambit＠iro.umontreal.ca 26 Nov '08

26 Nov '08

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comet web server
by francesco bracchi 26 Nov '08

26 Nov '08

I've extended some (contributed by me) dumping grounds packages and added some others, the result is a web server, that implements comet, using actor models to abstract push instead of publish/subscribe protocol. I'm experimenting too with functional reactive programming as a elegant solution to describe web user interfaces. the result could be downloaded via git: git clone git://git.berlios.de/futhark francesco bracchi

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Re: [gambit-list] Termite, IO and memory leakage
by Nicholas Walton 25 Nov '08

25 Nov '08

Christian, Many thanks for that. The code is pure R5RS until it hits Termite of course, no #!key or #!rest variables anywhere to be seen. All I/O is done by write, display or newline. I strongly suspect the problem is in Termite since weird things happen eg if I replace the (+ j j) in the example code with (newline)(write ..) I get the problem, but I also get the problem if I replace it with (if #t (+ j j) (begin (newline) (write ...))) Termite seems to pick up the possible I/O and crashes even if I/O is never executed. I therefore suspect a problem in the serialisation of ports but I can't be sure. NIck On Tuesday, November 25, 2008, at 01:48PM, "Christian Jaeger" <christian(a)pflanze.mine.nu> wrote: >Nicholas Walton wrote: >> Any ideas please? >> > >I can't really say anything about the memory leaking (I'm not a regular >Termite user). > >Regarding the segv's/bus errors, run the code under gdb and look at or >show the backtrace, this should give a clue on what's happening. Compile >with cc-options -g and with options keep-c or track-scheme for better >location reporting. > >Just to be sure, check whether you're using |print| or |println| or >defining own functions using both the #!key and #!rest syntax at the >same time, since Gambit has (afaik still) a known problem in the GC when >calling such procedures (it is triggered only when a GC happens in the >right place, so you'll only see it when you're calling such procedures >often). > >People having time to debug (not me currently) might appreciate a >complete example to reproduce the problem. > >Christian. > > >

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Relaxing moment
by Guillaume Cartier 17 Nov '08

17 Nov '08

For a relaxing moment using Gambit, try evaluating the following : (inexact->exact 2.2) ---------- the 2476979795053773/1125899906842624 result shows that Gambit does indeed smoke some powerfull stuff!

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Newbie question about Gambit and iPhone
by Chanwoo Yoo 16 Nov '08

16 Nov '08

Hello. Several days ago, I posted the next message in Google scheme group. "Hello. Nowadays, I'm trying to make ipod touch toy applications. When I write object-c or c code, I can't help miss macro and repl of lisp. As the subject, I hope that I develop core functions with lisp (e.g. In game application, they will be artificial intelligence parts), and make them into c dynamic or static libraries. If cocoa touch application can use shared libraries, object-c will be need in only GUI and controller parts. Is it possible? If it is possible, is there implementation which generate c libraries? I looked around ECL, bigloo, and some other lisps, but I couldn't find how to export symbols of var and function to external C and generate a library rather than make standalone executable. Would you recommend a good implementation(generate small binaries as possible, good documentation...) for it? Regards." And Mark answered me like below, so I tried to find how to build gambit code for iPhone application in Xcode. "Yes, with Gambit. See: https://webmail.iro.umontreal.ca/pipermail/gambit-list/2008-January/0...<https://webmail.iro.umontreal.ca/pipermail/gambit-list/2008-January/001966.…>" I went to the blog (http://weblog.latte.ca/blake/tech/iTouch/languages.html) and try to find how he makes it. But I didn't find any hint. And I read the manual of Gambit and searched in all Gambit list archives for examples of C interoperation. Shamely, because I don't know much about gcc build process and options, I can't figure out how I can apply them into Xcode build process. So I decided to try it in every way. First, I asserted that my mac can generates an executable. bash-3.2$ gsc -c m2.scm bash-3.2$ gsc -c m3.scm bash-3.2$ gsc -link m2.c m3.c bash-3.2$ gcc m1.c m2.c m3.c m3_.c -I/usr/local/Gambit-C/current/include -L/usr/local/Gambit-C/current/lib -lgambc bash-3.2$ ./a.out ((2 . 2) (4 . 4) (8 . 8) (16 . 16)) Next, I tried to compile "tests/server.scm" example in Xcode iPhone application project. Because I didn't know hot it goes, I added all files in "/usr/local/Gambit-C/current/include" and "usr/local/Gambit-C/current/lib" into Xcode project. And I copied generated c files and server.h file except client.c into Xcode project. I tried next combinations. all .a files in usr/local/Gambit-C/current/lib + Gambit.h + generated "server.c" by "gsc -c server.scm" + server.h copied into Xcode project, and "Build and Go" all .a files in usr/local/Gambit-C/current/lib + Gambit.h + generated "server.c", "server_.c" by "gsc -link -flat server.scm" + server.h copied into Xcode project, and "Build and Go" all files in usr/local/Gambit-C/current/lib + Gambit.h + generated "server.c" by "gsc -c server.scm" + server.h copied into Xcode project, and "Build and Go" all files in usr/local/Gambit-C/current/lib + Gambit.h + generated "server.c", "server_.c" by "gsc -link -flat server.scm" + server.h copied into Xcode project, and "Build and Go" All they failed. I know I look stupid. ^_^;; Could I get some help if there is anyone who have built Gambit code in Xcode with c or object-c files? Thanks in advance.

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