Gambit-list Juin 2012

gambit-list@iro.umontreal.ca

19 participants
19 discussions

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

04 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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How to use define-syntax and cond-expand in one program?
by Sven Hartrumpf 03 Jul '12

03 Jul '12

Hi all. I debugged the following compilation problem (v. 4.6.6): I am using 'gsc -:s ' because I need define-syntax, but then cond-expand is not working correctly. Any solutions? Sven

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Hooking the REPL reader
by Jeff Read 30 Jui '12

30 Jui '12

Hi all, Is there a way to hook the reader of the REPL to capture and do something with the expression that's read before the evaluator evaluates it? I don't want to change the expression before it hits the evaluator, just remember it.

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gambit-c and Subsystem for UNIX-based applications
by Cristian Baboi 17 Jui '12

17 Jui '12

After replacing config.sub and config.guess from: http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.gues… http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;… then runnig from C-Shell: ./configure --enable-single-host --enable-c-opts --enable-inline-jumps --enable-shared make bootstrap gives: os_base.c: In function `___err_code_from_h_errno': os_base.c:889: error: `NETDB_INTERNAL' undeclared (first use in this function) os_base.c:889: error: (Each undeclared identifier is reported only once os_base.c:889: error: for each function it appears in.) os_base.c:904: error: `NETDB_SUCCESS' undeclared (first use in this function)

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gsc doesn't build with vs2008.bat
by Cristian Baboi 17 Jui '12

17 Jui '12

After removing call "C:\Program Files\Microsoft Visual Studio 9.0\VC\bin\vcvars32.bat", calling misc/vs2008.bat in gambc-v4_6_6 sources from VS2010 command prompt gives these errors for gsc: _gambcgsc.obj : error LNK2001: unresolved external symbol _____20___t_2d_univ _gambcgsc.obj : error LNK2001: unresolved external symbol _____20___codegen _gambcgsc.obj : error LNK2001: unresolved external symbol _____20___x86 _gambcgsc.obj : error LNK2001: unresolved external symbol _____20___asm _gambcgsc.obj : error LNK2001: unresolved external symbol _____20___assert gsc.exe : fatal error LNK1120: 5 unresolved externals

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format
by Klaus Schilling 17 Jui '12

17 Jui '12

Is there a library for gambit-c implementing something on the lines of Common Lisp's format? Klaus Schilling

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Character out of range
by François Magnan 14 Jui '12

14 Jui '12

Hi, I got the following error in Gambit-C (4.6.4 compiled for iOS) *** ERROR IN (string)(a)1.7862 -- Character out of range What does it mean? Thank you, Francois

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What papers and strategies underly Gambit's design, in particular the compiler & VM?
by Mikael 13 Jui '12

13 Jui '12

Hi, In the purpose of making it clear and easy-enough for the unintroduced to understand the inner workings of Gambit in its current version, it'd be great to know what strategies/philosophies, papers and other reference documents underly Gambit - its compiler, environment and so on, beyond the Scheme (R5RS etc.) and SRFI specs. I'd be happy to make a Wiki page, Theory and papers, or alike, of this. My best understanding is that compilation to C/asm of Scheme with callcc support generally is perceived as a process that's intricate and of an abstract nature, asking this quite a lot therefore. :-) The papers I'm aware of are basically those on Marc's homepage and those listed by Alex below. And, beyond knowing which they are, it'd be great to have a clue of how central the respective paper is in Gambit's particular design / how strictly it was adhered to, on the scale from directly/being implemented as it is to indirectly/used rather for inspiration. Things whose answers can be found in the papers would include: * How the internal value, object, procedure and closure representations look and fit together Closures effectively special-purpose vectors of boxes? All values and object references are internally native-size integers with a number of reserved bytes describing the value type, what about them? * Value and object allocations, made how and what optimizations for fast dead object detection and subsequent reclaim are there * The layout of the asm/C-level stack and trampolines and how the GC resolves the locations of all object reference, anatomy of a procedure call and return * How the CPS transformation works * What optimizations are made, in terms of register use optimizations, compile-time pre-evaluation or deductions of datatype At some point I got that generally |cdr| is translated to +1 in asm/c, for instance * What does the internal form of interpreted code actually look/work like * Interrupt checks, made provenly at what granularity * Code debuggability, made in compiled code on what basis * Motivations for the GVM code's design * Hashtable algorithm * Number handling I suppose there's key areas beyond these also. And, I suppose quite possibly, some key things are not described in any paper. Find below an attempt to figure out which of Marc's papers are in use for these respects of Gambit today. If you know such papers/docs or you see areas beyond those listed above that ought to be considered as in the scope too, please tell. Kind regards, Mikael * Marc Feeley. *Speculative inlining of predefined procedures in an R5RS Scheme to C compiler. *In Olaf Chitil, Zoltán Horváth, and Viktória Zsók, editors, *Implementation and Application of Functional Languages (IFL'07)*, volume 5083 of *Lecture Notes in Computer Science*, pages 237-253, 2008. [PDF] <http://www.iro.umontreal.ca/~feeley/papers/FeeleyIFL07.pdf> * Fernanda Kri and Marc Feeley. *Genetic instruction scheduling and register allocation. *In *International Conference on the Quantitative Evaluation of Systems (QEST'04)*, pages 76-83, 2004. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/KriFeeleyQEST04.pdf> * Marc Feeley. *A better API for first-class continuations. *In *Scheme and Functional Programming Workshop (SFPW'01)*, pages 1-3, September 2001. [PDF] <http://www.iro.umontreal.ca/~feeley/papers/FeeleySW01.pdf> * Danny Dubé and Marc Feeley. *Demand-driven type analysis: an introduction. *In *Scheme and Functional Programming Workshop (SFPW'01)*, pages 21-32, September 2001. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/DubeFeeleySW01.pdf> * Marc Feeley. *A portable implementation of first-class continuations for unrestricted interoperability with C in a multithreaded Scheme. *In *Scheme and Functional Programming Workshop (SFPW'00)*, pages 65-66, September 2000. [PDF] <http://www.iro.umontreal.ca/~feeley/papers/FeeleySW00.pdf> * Mauricio Solar and Marc Feeley. *Scheduling algorithm considering latency time on a shared-memory machine. *In *XVI World Computer Congress, International Conference on Software: Theory and Practice*, August 2000. * Marc Feeley, James S. Miller, Guillermo J. Rozas, and Jason A. Wilson. *Compiling higher-order languages into fully tail-recursive portable C. *Technical Report 1078, département d'informatique et r.o., Université de Montréal, August 1997. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/FeeleyMillerRozasWilsonDIRO1078.…> * Dominique Boucher and Marc Feeley. *Abstract compilation: a new implementation paradigm for static analysis. *In *International Conference on Compiler Construction (CC'96)*, pages 192-207, April 1996.[PDF]<http://www.iro.umontreal.ca/~feeley/papers/BoucherFeeleyCC96.pdf> * Manuel Serrano and Marc Feeley. *Storage use analysis and its applications. *In *ACM SIGPLAN International Conference on Functional Programming (ICFP'96)*, pages 50-61, May 1996. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/SerranoFeeleyICFP96.pdf> * Marc Feeley. *Polling efficiently on stock hardware. *In *ACM Conference on Functional Programming Languages and Computer Architecture (FPCA'93)*, pages 179-187, 1993. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/FeeleyFPCA93.pdf> * Marc Feeley and Guy Lapalme. *Closure generation based on viewing LAMBDA as EPSILON plus COMPILE. **Computer Languages*, 17(4):251-267, 1992. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/FeeleyLapalmeCL92.pdf> Marc Feeley and Guy Lapalme. *Using closures for code generation. **Computer Languages*, 12(1):47-66, 1987. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/FeeleyLapalmeCL87.pdf> * Marc Feeley. *Deux approches à l'implantation du language Scheme. *Master's thesis, Université de Montréal, May 1986. [PDF]<http://www.iro.umontreal.ca/~feeley/papers/FeeleyMSc.pdf> 2011/6/9 Alex Queiroz > Hallo, > > On Wed, Jun 8, 2011 at 11:14 PM, Jason E. Aten <j.e.aten(a)gmail.com> wrote: > > > > If others on the list have pointers to papers as well, I'd enjoy reading > > about the best thoughts on how to implement continuations. > > > > "Representing Control in the Presence of First-Class Continuations" > http://www.cs.indiana.edu/~dyb/papers/stack.ps > > "A portable implementation of first-class continuations for > unrestricted interoperability with C in a multithreaded Scheme" > http://repository.readscheme.org/ftp/papers/sw2000/feeley.pdf > > "Implementation strategies for first-class continuations" > http://www.springerlink.com/content/h5808n962434j275/fulltext.pdf > > More in: > http://library.readscheme.org/page6.html > > Cheers, > -- > -alex >

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___setup memory corruption(?) on iPhone
by Kirill Zorin 11 Jui '12

11 Jui '12

Hi all, I've built (a slow version of) Gambit with llvm-gcc 4.2 on Mac OS X, targeted for the iPhone, using the build-gambit-iOS script, for the iOS 5.1 SDK. (I can't build it with latest clang, because for whatever reason Gambit's configure exits with various autoconf-related errors when clang is used.) When I run ___setup(...) as required, from a separate thread, the function never returns. If I call it from the main thread it returns, except that after that, various Apple libraries begin to crash in mysterious ways. If I don't run ___setup(...) at all (from any thread), everything works fine. (Except, of course, that I can't run Scheme code =)) Any ideas what could be at fault here (i.e. what I'm doing wrong)? For comparison, the same scenario (exactly the same code, linkage, etc.) built for Mac OS X works as required regardless of what thread ___setup() is called from initially. Thanks.

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Fwd: Puzzlement (different behavior of compiled code)
by David Rush 10 Jui '12

10 Jui '12

forgot to include the list in the correspondence. This is the (happy) outcome... ---------- Forwarded message ---------- From: David Rush <kumoyuki(a)gmail.com> Date: 10 June 2012 15:44 Subject: Re: [gambit-list] Puzzlement (different behavior of compiled code) To: Mikael <mikael.rcv(a)gmail.com> Ta much Mikael! It turns out that the -:s flag to gsc is the culprit. I had been using that flag out of habit to get the syntax-case expander - apparently it also interferes with recognizing keywords. I think i need "-:S" instead, which i guess has been added since I last update my Gambit makefiles (don't ask - it's been a while) thanks again - d On 10 June 2012 15:27, David Rush <kumoyuki(a)gmail.com> wrote: > On 10 June 2012 14:31, Mikael <mikael.rcv(a)gmail.com> wrote: >> >> Uh this is funny: >> >> (open-output-file '(|path:| "test.flog" |create:| maybe |append:| #t)) >> >> look there, there's |:s around the keywords. This means they're *not* >> actually keywords but *symbols* that kind of look like keywords. > > That is interesting. I have no idea why, as I said it's the same code > in both cases (code was included in the tail of the OP) > >> Tried to reproduce your error on 4.6.2: >> >> $ cat a.scm >> (write (cons abcde: 123)) >> $ gsi a.scm >> (abcde: . 123)$ gsc -exe a.scm >> $ ./a >> (abcde: . 123) > > I wonder if mine is a case that occurs because the code renames cons > (in an attempt to avoid variable capture while expanding macros) so > that instead of cons the var referenced is actually _cons_23 - leading > to compiler confusion about special cases. > >> Do you compile this code just with gsc filename.scm or (compile-file >> "filename.scm") or do you have some preprocessor on it? > > from the original message: > > ----------------------------------------------------------------------- > drr@dibbuk$ make target=gambit test/bug.gambit > gsc -:s -link test/bug.Gambit > gcc -I/home/drr/include test/bug.c test/bug_.c -o test/bug.gambit \ > -L/home/drr/lib -lgambc -lm -lutil -ldl > ------------------------------------------------------------------------ > > which is something of a habit i have with Gambit going back many years > in order to actually insert a lot of gcc optimization flags (*not* > included in this test case) > >> Do you see any other reasons for why this occured? > > just what I suggested above. It gives me something to try anyway. > > d > -- > GPG Public key at http://cyber-rush.org/drr/gpg-public-key.txt -- GPG Public key at http://cyber-rush.org/drr/gpg-public-key.txt -- GPG Public key at http://cyber-rush.org/drr/gpg-public-key.txt

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Gambit-list Juin 2012