August 2010 - Gambit-list - mailman.iro.umontreal.ca

Edge triggered I/O with libevent
by Adam Langley 04 Apr '13

04 Apr '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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How to pass a u8vector to the FFI
by Mikael 20 Sep '11

20 Sep '11

You do this, by declaring the passed u8vector as a scheme-object in the c-lambda definition. The memory pointer to the u8vector's contents in the C code is resolved by void *u8vectorptr = ___CAST(void*,&___FETCH_U8(___BODY(theu8vectorschemeobjectvariable),___INT(0))); Remember that the pointer is only to be kept until the next return to Scheme. Mikael 2010/3/30 Álvaro Castro-Castilla <alvaro.castro.castilla(a)gmail.com> > Hi! > > Is there a way to pass a u8-vector to a FFI interface somehow? > The way I expect this to work is through a (pointer unsigned-char), but it > obviously doesn't work, claiming a proper C pointer. I would like to be able > to build this arrays from Scheme code. Is there a way? > > Currently I have to call a FFI function to set char by char, calling the > c-lambda function too many times. > > One thing that could work is something that converts u8-vectors to unsigned > char* arrays, does that exist in Gambit? > > > Thanks, > > Álvaro > > _______________________________________________ > Gambit-list mailing list > Gambit-list(a)iro.umontreal.ca > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-list > >

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problems with development release
by hendrik＠topoi.pooq.com 15 Sep '10

15 Sep '10

I just downloaded, untarred, compiled, installed gambc-v4_6_0.tgz But when I tried to use it Space-invaders-src-v1.0.tgz I got errors that look like C/C++ compatibility problems. I compiled and installed gambit using C++; specifically, the g++ compiler. I had to modify the space invaders makefile to recognise that gambit was installed at /usr/local/gambit, and to tell it that my C compiler was g++. ## compilers GSC=$(PATH_TO_GAMBIT)/bin/gsc -:=$(PATH_TO_GAMBIT) CC=g++ ## Gambit-c # PATH_TO_GAMBIT=/usr/local/Gambit-C/current PATH_TO_GAMBIT=/usr/local/Gambit-C I then performed a make clean in the space-invaders directory to clear out the effects of mismaking with the wrong PATH_TO_GAMBIT and the wrong CC. hendrik@lovesong:~/dv/lang/gambit/expand/space-invaders$ make clean make: Warning: File `makefile' has modification time 93 s in the future rm -f coroutine.c engine.c event-simulation-macro.c event-simulation.c font-macro.c font.c glu-header.c glu.c glut-header.c glut.c opengl-header.c opengl.c ppm-reader.c rbtree.c scm-lib-macro.c scm-lib.c sdl-interface.c sdl-user-interface.c sprite-macro.c sprite.c texture-macro.c texture.c user-interface-images.c user-interface.c *_.c *.o* space-invaders.exe *.tar.gz *.tgz *.~*~ *.zip make clean -C doc make: *** doc: No such file or directory. Stop. make: *** [clean] Error 2 Upon doing make OS=linux UI=glut The errors I got were hendrik@lovesong:~/dv/lang/gambit/expand/space-invaders$ make OS=linux UI=glut make: Warning: File `makefile' has modification time 81 s in the future *** Global Variables *** OS=linux UI=glut *** Currently using following paths *** PATH_TO_GAMBIT=/usr/local/Gambit-C PATH_TO_GL=/usr *** Beginning compilation *** /usr/local/Gambit-C/bin/gsc -:=/usr/local/Gambit-C -c opengl.scm g++ -I/usr/local/Gambit-C/include -I/usr/include/GL -I/usr/include/GL -c opengl.c opengl.c:60019: warning: deprecated conversion from string constant to ‘char*’ /usr/local/Gambit-C/bin/gsc -:=/usr/local/Gambit-C -c glu.scm g++ -I/usr/local/Gambit-C/include -I/usr/include/GL -I/usr/include/GL -c glu.c glu.c: In function ‘int ___H__20_glu_23_641(___processor_state_struct*)’: glu.c:39781: warning: overflow in implicit constant conversion glu.c: In function ‘int ___H__20_glu_23_657(___processor_state_struct*)’: glu.c:40759: error: invalid conversion from ‘const void*’ to ‘void*’ glu.c: In function ‘int ___H__20_glu_23_659(___processor_state_struct*)’: glu.c:40883: error: invalid conversion from ‘const void*’ to ‘void*’ glu.c: At global scope: glu.c:46535: warning: deprecated conversion from string constant to ‘char*’ make: *** [glu.o] Error 1 hendrik@lovesong:~/dv/lang/gambit/expand/space-invaders$ My guess is that one crucial macro within the gambit include files fails to deal with 'const' properly. Or is there some obscure way I'm getting C code instead of C++? -- hendrik

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[ANN] LAST CHANCE TO REGISTER ONLINE for 2010 Workshop on Scheme and Functional Programming
by Marc Feeley 17 Aug '10

17 Aug '10

The 2010 Scheme Workshop will be held in Montreal in less than 4 days from now. If you are planning to attend the workshop ***PLEASE REGISTER ONLINE ASAP***. By going through the online registration process we will get vital information for the workshop (badge data, dietary restrictions, T-shirt size, and proceedings preference). You can register on-site saturday morning but in that case we will not be able to take your information into consideration and planning the food for lunch will be difficult (i.e. we may not be able to provide lunch for you and a complimentary T-shirt). Please register online by ***THURSDAY AUGUST 18 AT 8 AM EDT*** To register online visit: http://www.iro.umontreal.ca/~sfp2010/registration.html Marc Feeley 2010 Scheme Workshop chair

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[ANN] Call for Participation for 2010 Workshop on Scheme and Functional Programming
by Marc Feeley 07 Aug '10

07 Aug '10

[The early registration deadline is only 2 days from now. Please register ASAP!] CALL FOR PARTICIPATION 2010 Workshop on Scheme and Functional Programming Montreal, Quebec, Canada Saturday and Sunday August 21-22, 2010 http://www.iro.umontreal.ca/~sfp2010 *** ONLINE REGISTRATION IS NOW OPEN FOR THE WORKSHOP *** *** REGISTER BEFORE AUGUST 10 TO AVOID LATE REGISTRATION FEES *** PURPOSE The 2010 Workshop on Scheme and Functional Programming provides a forum for discussing experience with and future development of the Scheme programming language. The scope of the workshop includes all aspects of the design, implementation, theory, and application of Scheme. We encourage everyone interested in Scheme to participate. FORMAT The workshop will be held on the Université de Montréal campus Saturday and Sunday August 21-22, 2010. The workshop will start at 8 AM August 21 and end around noon on August 22. This year's departure from the traditional one day format will leave room for special events (lightning talks, social outing, etc). *** IF YOU ARE INTERESTED IN GIVING A LIGHTNING TALK, PLEASE CONTACT THE WORKSHOP CHAIR FOR DETAILS ASAP EVEN IF YOU ARE NOT 100% SURE *** Other information is available on the workshop web site: - Workshop program (http://www.iro.umontreal.ca/~sfp2010/program.html) - Travel, accommodation and tourism information (http://www.iro.umontreal.ca/~sfp2010/travel.html) - Online registration (http://www.iro.umontreal.ca/~sfp2010/registration.html) Marc Feeley Scheme Workshop Chair feeley at iro.umontreal.ca

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Bug (?) with BlackHole and append!
by Yves Parès 06 Aug '10

06 Aug '10

Hello, I have a file "test.scm" containing the following lines: (import (std srfi/1)) (define a '(3 2 4 2)) (append! a '(8 8 8)) (display a) (newline) When I lauch: gsc -e '(load "~~/lib/modules/build")' - and then (import test) it displays '(3 2 4 2 8 8 8)', which is fine. But if 'test' has been compiled first with (module-compile! 'test), then when importing I got the error: *** ERROR IN ##main -- (Argument 1) MUTABLE object expected (set-cdr! '(2) '(8 8 8)) (I use the last git version of BH)

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Re: [gambit-list] {Spam?} Spork issue
by Milan Markovic 04 Aug '10

04 Aug '10

I think Racket (formerly PLT Scheme) uses continuations in their web apps. Here's a link to their doc page: http://docs.racket-lang.org/web-server/index.html > Message: 2 > Date: Tue, 03 Aug 2010 23:17:00 +0400 > From: Valeriya Alex <valery(a)digitalchile.net> > Subject: Re: [gambit-list] {Spam?} Spork issue > (kCFErrorDomainCFNetwork error 303.) > To: Per Eckerdal <per.eckerdal(a)gmail.com>, > gambit-list(a)iro.umontreal.ca > Message-ID: <4C586B2C.6030804(a)digitalchile.net> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > One more question > > Does anybody has the copy of this page > http://mwaza.dyndns.org/apps/files/bh-tutorial.html ? > > Or maybe there are some examples of the site with the Spork ( I am > interested to see any code which uses continuation web programming style ) > > > ------------------------------ > > _______________________________________________ > Gambit-list mailing list > Gambit-list(a)iro.umontreal.ca > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-list > > > End of Gambit-list Digest, Vol 71, Issue 3 > ****************************************** >

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[ANN] Call for Participation for 2010 Workshop on Scheme and Functional Programming
by Marc Feeley 04 Aug '10

04 Aug '10

Here is the final program for the 2010 Workshop on Scheme and Functional Programming. For the abstracts please check the website (http://www.iro.umontreal.ca/~sfp2010) To take advantage of the early registration price, please register by ***AUGUST 9***. Marc Feeley Saturday, August 21 8:15 On-site registration and breakfast 9:00 Invited Talk; To be announced Olin Shivers; Northeastern University 10:00 Break Session 1 10:30 Functional Data Structures for Typed Racket Hari Prashanth K R and Sam Tobin-Hochstadt; Northeastern University 11:00 Implementing User-level Value-weak Hashtables Aaron W. Hsu; Indiana University 11:30 Break Session 2 12:00 Pushdown Control-Flow Analysis of Higher-Order Programs Christopher Earl (1), Matthew Might (1), and David Van Horn (2); (1)University of Utah, (2)Northeastern University 12:30 Lightning talks Speakers to be announced at the workshop 12:45 Lunch break Session 3 14:00 Measuring the Effectiveness of Error Messages Designed for Novice Programmers Guillaume Marceau (1), Kathi Fisler (1), and Shriram Krishnamurthi (2); (1)Worcester Polytechnic Institute, (2)Brown University 14:30 JazzScheme: Evolution of a Lisp-Based Development System Guillaume Cartier and Louis-Julien Guillemette; Auphelia Technologies Inc. 15:00 Break Session 4 15:30 The Design of a Functional Image Library Ian Barland (1), Robert Findler (2), and Matthew Flatt (3); (1)Radford University, (2)Northwestern University, (3)University of Utah 16:00 Enabling cross-library optimization and compile-time error checking in the presence of procedural macros Andrew Keep and R. Kent Dybvig; Indiana University 16:30 Break Session 5 17:00 Guiding Requirements for the Ongoing Scheme Standardization Process Mario Latendresse; SRI International 17:20 Lightning talks; Speakers to be announced at the workshop Sunday, August 22 8:15 Breakfast 9:00 Invited Talk; Contracts in Racket Robert Findler; Northwestern University 10:00 Break Session 6 10:30 Report by the Scheme Language Steering Committee and report by the Scheme Language Working Groups 12:00 Closing

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Re: [gambit-list] {Spam?} Spork issue (kCFErrorDomainCFNetwork error 303.)
by Valeriya Alex 03 Aug '10

03 Aug '10

One more question Does anybody has the copy of this page http://mwaza.dyndns.org/apps/files/bh-tutorial.html ? Or maybe there are some examples of the site with the Spork ( I am interested to see any code which uses continuation web programming style )

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Re: [gambit-list] {Spam?} Spork issue (kCFErrorDomainCFNetwork error 303.)
by Valeriya Alex 03 Aug '10

03 Aug '10

Thanks allot Per, Maybe you want publish this info to the your git's readme? Then what the Spork state is? I mean. Is it abandoned? On 8/3/10 10:36 PM, Per Eckerdal wrote: > Well... I'd say that the Sack specification is rather complete. It is more or less a Schemification of Ruby's Rack, which must be considered both complete and stable. The specification is not finished, and if it would be > > ... > > I do not have time to maintain it myself, but I will gladly accept patches and API improvements (but talk to me first to make sure that it goes in line with the rest of Sack). I'd love if anyone was interested to maintain it and move it forward, but I don't really expect that to happen. I put all my time I have on Gambit related things on Black Hole. > > /Per >

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