Mars 2007 - Gambit-list - mailman.iro.umontreal.ca

Edge triggered I/O with libevent
by Adam Langley 05 Avr '13

05 Avr '13

Gambit uses the select call on POSIX systems to multiplex IO operations. This is fine for small numbers of file descriptors, but falls apart quickly with large numbers[1]. libevent[2] is a wrapper library around a number of modern IO multiplexing systems (epoll on Linux, kqueue on the BSDs as well as poll and select). Attached is a patch which converts Gambit to using edge triggered I/O with epoll and libevent. This also requires a patch (attached) of libevent since the standard distribution doesn't include edge triggering support and the upstream appears to be on holiday. (epoll is required because I don't have a BSD box on which to develop edge triggering support for kqueue) This patch (for Gambit) preprocesses away to nothing unless --enable-libevent is passed to the configure script. (Note that, since this patches the configure.ac script, you'll need to run autoconf to regenerate). I hope I've not broken anything, but at this stage I've only tested that the console and tcp ports work. This patch (in the future) should also allow people, who write programs which use socket calls directly, to integrate into the main event loop at some point. Testing is more than welcome and, if you find a form of IO which is broken, please email me. [1] http://monkey.org/~provos/libevent/libevent-benchmark2.jpg [2] http://monkey.org/~provos/libevent/ -- Adam Langley agl(a)imperialviolet.org http://www.imperialviolet.org (+44) (0)7906 332512 PGP: 9113 256A CC0F 71A6 4C84 5087 CDA5 52DF 2CB6 3D60

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Re: [gambit-list] compiler bug?
by Marc Feeley 03 Sep '07

03 Sep '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 25-Sep-06, at 3:48 PM, Sven.Hartrumpf(a)FernUni-Hagen.de wrote: > Hello Marc. > > I have a large program which behaves a little different > with gsc than any other Scheme I know of (bigloo, chicken, gauche): > Here is the problematic region: > > (let* ((orth (and (pair? word-info) > ;(not (eq? (caar word-info) 'words)) > (fs-value (car word-info) '(orth)))) > (orth-l (if orth (string-length orth) 0)) > (left-hyphen (and (> orth-l 2) > (char=? (string-ref orth 0) # > \-))) ; examples: \quw{Steuergesetzgebung und -verwaltung}, \quw > {auspringen und -setzen} > (right-hyphen (and (> orth-l 1) > (char=? (string-ref orth (- orth- > l 1)) #\-))) > (step (if left-hyphen > (and (not right-hyphen) > -1) > (and right-hyphen > 1)))) > > left-hyphen and right-hyphen are evaluated to #f for some binding - > this > is as expected. But step is bound to 1 which seems wrong to me. > Minimizing the problem might be hard for me, so I hope that you can > see > the problem already :-) > > Ciao > Sven Sven, you have just uncovered a nasty bug in the compiler. In beta 18 the transformation for the "and" form is too aggressive in the case where the second argument is a constant. As far as I can tell this bug was introduced just before beta 18 was released. Surprisingly in the 70Kloc in the Gambit runtime system and compiler this case does not occur. I have now fixed the bug and will release beta 19 shortly because this is a serious bug. Thanks! Marc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (Darwin) iD8DBQFFGEqS//V9Zc2T/v4RAqTeAJ9asp7elGoK7yqa6MzmLFTRj6K8UwCfc3d4 5haROCNvlgMs1NREyZCgYIw= =bvLI -----END PGP SIGNATURE-----

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Appending 32bit integers to a file
by Phil Dawes 30 Mar '07

30 Mar '07

Hi Gambit List, What's the simplest way to append 32bit unsigned integers to a file in gambit? (not bothered about maintaining endian portability or anything) I'm currently using a C hack (see below), but it feels like there ought to be something less clunky. Thanks, Phil (c-declare "#include <stdio.h>") (define fopen (c-lambda (nonnull-char-string nonnull-char-string) (pointer "FILE") "fopen")) (define fclose (c-lambda ((pointer "FILE")) int32 "fclose")) (define write-u32vector-to-file ; args: port, u32-vector, len (c-lambda ((pointer "FILE") scheme-object unsigned-int32) int32 "___result = fwrite((void*)(___BODY_AS(___arg2,___tSUBTYPED)), 4, ___arg3, ___arg1);")) (define read-u32vector-from-file ; args: port, u32-vector, len (c-lambda ((pointer "FILE") scheme-object unsigned-int32) int32 "___result = fread((void*)(___BODY_AS(___arg2,___tSUBTYPED)), 4, ___arg3, ___arg1);"))

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gambit's list displaying is not very pretty
by dillo gimp 28 Mar '07

28 Mar '07

(display (list (list 1 2 ) 3)) 123 how do I properly display ((1 2) 3)? thanks

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ssax-sxml for gambc-4.0b21
by Aycan iRiCAN 28 Mar '07

28 Mar '07

Here is the proper Makefile of ssax-sxml-gambit-060529.tgz for gambit 4.0 beta 21. You should change the prefix variable before using this Makefile. Best Regards, -- Aycan iRiCAN KOR Bilişim Teknolojileri http://www.core.gen.tr/

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ssax-sxml for gambc-4.0b21
by Aycan iRiCAN 28 Mar '07

28 Mar '07

This a slightly modified Makefile that creates a shared-library and a loadable library for ssax-sxml-gambit-060529.tgz. Here is an example transcript for loadable ssax-sxml library. ssax-sxml $ gsi Gambit Version 4.0 beta 21 > (load "ssax-sxml") "/tmp/ssax-sxml/ssax-sxml.o1" > (ssax:xml->sxml (open-input-string "<example>Peace at home, peace in the world.</example>") '()) (*TOP* (example "Peace at home, peace in the world.")) > (sxml:document "http://library.readscheme.org" '()) (*TOP* (html (head (title "Bibliography of Scheme-related Research") (meta (@ (name "generator") (content "SchemeBib and Site-ML"))) (meta (@ (name "description") (content "Online bibliography of Scheme research"))) (meta (@ (name "keywords") (content "Scheme, bibliography, research"))) ... ... Best Regards, -- Aycan iRiCAN KOR Bilişim Teknolojileri http://www.core.gen.tr/

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Re: [gambit-list] Conflict bewteen #<<c-declare-end and syntax-case?
by Raffael Cavallaro 25 Mar '07

25 Mar '07

On Feb 7, 2007, at 8:06 PM, Marc Feeley wrote: > It's probably easy to fix for the implementors of syntax-case > (Dybvig et al), but I shudder at the thought of figuring out which > of the over 40 usages of 'quote in syntax-case.scm has to be made > conditional on the object being quoted (the quote should be dropped > for strings, numbers, booleans, and characters). Given that you can't fix syntax-case.scm, would it be possible to modify c-declare, etc. so that they take both strings and quoted strings? regards, Ralph Raffael Cavallaro, Ph.D. raffaelcavallaro(a)mac.com

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Commercial support?
by a Human Being 25 Mar '07

25 Mar '07

Hi guys We are looking for commercial support (in Europe) for the Gambit-C compiler and runtime system (and Termite too). Any ideas ? Chris

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Trying to run Emacs with Gambit-C
by urrozalf＠vcn.bc.ca 24 Mar '07

24 Mar '07

Hello there Scheme gurus, I am trying to run Gambit-C and using Emacs as the editor, but I can't fugure out how to do it. First of all I am running Solaris 9 on an old Sun box. I have downloaded the Gambit files and the Emacs files, expanded and made both of them. At the beginning I was having some issues with the PATH, but I have that fixed right now. I can use the Gambit Interpreter (gsi) and the compiler (gsc). The problem is, I have to use a separate text editor, to edit the files, and here is where I wan to use Emacs. What I have right now, is the following structure /export/home/alfonso/MyPrograms/Gambit-C/ and also /export/home/alfonso/MyProgrmas/Emacs/ I also know, that I have this, somewhere else on the hard drive: /usr/local/Gambit-C/ I don't know, how it got there, but there it is. I created an .emacs file, 0n /export/home/alfonso/ which contains the following: (autoload 'gambit-inferior-mode "gambit" "Hook Gambit mode into cmuscheme.") (autoload 'gambit-mode "gambit" "Hool Gambit mode into scheme.") (add-hook 'inferior-scheme-mode-hook (function gambit-inferior-mode)) (add-hook 'scheme-mode-hook (function gambit-mode)) (setq scheme-program-name "gsi -:d-") (setq load-path (cons "/usr/local/Gambit-C/share/emacs/site-lisp" load-path)) (setq scheme-program-name "/tmp/gsi -:d-") (setq gambit-highlight-color "gray") (setq ganbit-repl-command-prefix "-e") (require 'gambit) When I type emacs, open the editor, but it tell me, there is an error, if I remove the (require 'gambit) line and do 'M-x run-scheme' it tells me there is an error also. I don't know what I am doing wrong, or what I am missing, please help me to figure out this problem, I know I am pretty close, but no cigar. If I can't figure this thing out, I will have to go and dowmload PLT scheme, for UNix, and give it a try. Thanks. Alfonso G. Urroz

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Meroon and syntax-case?
by Phil Dawes 23 Mar '07

23 Mar '07

Hi Gambit List, I really like the meroonet object system, however my program contains quite a few syntax-case macros and the meroonet common-lisp style macros don't work once syntax-case is loaded. I've found that I can switch between the two macro systems using: (define (switch-to-lisp-macros) (set! ##expand-source (lambda (src) src))) (define (switch-to-syntax-rules-macros) (set! ##expand-source (lambda (src) (sc-expand src)))) ... however this is both a hassle and a global change which I'm guessing prob won't work with threading etc.. Has anybody attempted to build a meroon style system using syntax-case macros? Any pointers would be much appreciated. Many thanks, Phil

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