Gambit-list Mars 2018

gambit-list@iro.umontreal.ca

11 participants
16 discussions

Gambit versus Python+GMP: Timing for Chudnovskys' algorithm for pi
by Bradley Lucier 07 Avr '22

07 Avr '22

Bakul Shah wrote a particularly elegant Scheme program for Chudnovskys' algorithm for pi based on the Common Lisp program here: https://bitbucket.org/tarballs_are_good/numericl/src/5fe8fe7089f48ab1c8a388… Nick Craig-Wood wrote a Python program using the GMP multiprecision library that appears to use exactly the same algorithm here: http://www.craig-wood.com/nick/articles/pi-chudnovsky/ I modified both programs a bit and include them here. They time the calculation of $10^n$ digits of pi for $n=1,2,3,4,5,6,7$. The results are heine:~/programs/gambiteer/gambit> !py python pi_chudnovsky_bs_gmpy.py 31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679 ('chudnovsky_gmpy_mpz_bs: digits', 10, 'time', 1.0967254638671875e-05) ('chudnovsky_gmpy_mpz_bs: digits', 100, 'time', 3.0040740966796875e-05) Last 5 digits 70679 OK ('chudnovsky_gmpy_mpz_bs: digits', 1000, 'time', 0.00025582313537597656) Last 5 digits 01989 OK ('chudnovsky_gmpy_mpz_bs: digits', 10000, 'time', 0.00386810302734375) Last 5 digits 75678 OK ('chudnovsky_gmpy_mpz_bs: digits', 100000, 'time', 0.0834801197052002) Last 5 digits 24646 OK ('chudnovsky_gmpy_mpz_bs: digits', 1000000, 'time', 1.655979871749878) Last 5 digits 58151 OK ('chudnovsky_gmpy_mpz_bs: digits', 10000000, 'time', 30.67442488670349) Last 5 digits 55897 OK heine:~/programs/gambiteer/gambit> gsi chud1.scm Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10, CPU time: 0.. Last 5 digits 26535. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100, CPU time: 0.. Last 5 digits 70679. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000, CPU time: .004. Last 5 digits 1989. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000, CPU time: .028. Last 5 digits 75678. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000, CPU time: .472. Last 5 digits 24646. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000, CPU time: 6.448. Last 5 digits 58151. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000000, CPU time: 98.612. Last 5 digits 55897. So it appears that for this algorithm applied to large integers, GMP's bignum routines are about 3-4 times as fast as Gambit's bignum routines. Not so bad. For smaller bignums, GMP has a bigger advantage. The C program gmp-chudnovsky.c includes certain optimizations to this basic algorithm: http://gmplib.org/pi-with-gmp.html ftp://ftp.gmplib.org/pub/misc/gmp-chudnovsky.c On my machine, compiled with gcc -O3 -march=native -o gmp-chudnovsky gmp-chudnovsky.c -lgmp -lm the CPU times for 1,000,000 and 10,000,000 digits are 1.064 and 18.200 seconds, respectively. This is with a somewhat older machine model name : Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz running Ubuntu 13.04 with heine:~/programs/gambiteer/gambit> gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.3-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl --disable-cloog-version-check --disable-ppl-version-check --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) heine:~/programs/gambiteer/gambit> gsi -v v4.6.9 20130607151908 x86_64-unknown-linux-gnu "./configure '--enable-single-host' '--enable-multiple-versions' '--enable-shared'" and the Ubuntu-provided GMP 5.0.5. (I'm sure the GMP folks have a better way to build GMP on my machine than the "generic" 64-bit version provided by Ubuntu.) Brad

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Missing string matching functions
by C K Kashyap 31 Mar '18

31 Mar '18

Hi, I am trying to write an automation script in gsi (on windows). I just realized that there does not seem to be a string match function built into gambit. Is there a recommended way to use string-search or regex for that matter? Regards, Kashyap

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Some questions on tls contexts
by Dimitris Vyzovitis 26 Mar '18

26 Mar '18

Marc, Post refcount release bug, I've been looking more closely into the implementation of tls contexts, and I have a couple of questions 1. The tls context contains internally allocated data, that is released immediately with ___release_rc_tls_context in failure paths of ___os_make_tls_context. However, I am not convinced it gets cleaned up when the tls context is reclaimed by the gc. Is there a finalizer for tls contexts or do we leak that internal memory? 2. Is there a need to make a tls context per socket or can the tls context be reused and shared among many (concurrent) sockets? Currently I make a new context every time I make an https request, but it would be very nice if a single context could be reused. -- vyzo

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question about implementation of force
by Dimitris Vyzovitis 25 Mar '18

25 Mar '18

Marc, in _std.scm you have the following code implementing force: (define-prim (##force obj) (if (##promise? obj) (let ((result (##promise-result obj))) (if (##eq? result obj) (let* ((r ((##promise-thunk obj))) (result2 (##promise-result obj))) (if (##eq? result2 obj) (begin (##promise-result-set! obj r) (##promise-thunk-set! obj #f) r) result2)))) ;; XXX -- value is unspecified when (not (##eq? result obj)) obj)) I find it very strange that the first if eq test of the result to the promise is lacking the else part; that's where I marked with XXX. Shouldn't the code return result in this case? What am I missing here? -- vyzo

2 3

detecting closed ports
by Dimitris Vyzovitis 24 Mar '18

24 Mar '18

Is there a reasonable way to detect whether a port has been closed? I want to implement input-port-open? and output-port-open? for r7rs coverage... -- vyzo

3 6

The monster that killed gcc
by Dimitris Vyzovitis 23 Mar '18

23 Mar '18

The attached file results in a 140kloc monster that results in gcc dying with OOM after several minutes of effort, and I would like to understand why. Any ideas? -- vyzo

4 17

Process stdout redirection
by C K Kashyap 20 Mar '18

20 Mar '18

Hello all, I was hoping for this program to redirect the output of the forked process into a file - (define program (list path: "ls" stdout-redirection: #f arguments: (list "-l"))) (with-output-to-file (list path: "output.txt") (lambda () (open-process program))) But that does not seem to happen. I am not sure what I am missing here. Regards, Kashyap

3 5

Good way to slurp in gambit
by C K Kashyap 20 Mar '18

20 Mar '18

Hi, Could someone please tell me whats the gambit way to "slurp" a file? Regards, Kashyap

4 5

Call for Tutorial Proposals: ICFP 2018
by Lindsey Kuper 18 Mar '18

18 Mar '18

CALL FOR TUTORIAL PROPOSALS ICFP 2018 23rd ACM SIGPLAN International Conference on Functional Programming September 23-29, 2018 St. Louis, Missouri, United States http://conf.researchr.org/home/icfp-2018 The 23rd ACM SIGPLAN International Conference on Functional Programming will be held in St. Louis, Missouri, United States on September 23-29, 2018. ICFP provides a forum for researchers and developers to hear about the latest work on the design, implementations, principles, and uses of functional programming. Proposals are invited for tutorials to be presented during ICFP and its co-located workshops and other events. These tutorials are the successor to the CUFP tutorials from previous years, but we also welcome tutorials whose primary audience is researchers rather than practitioners. Tutorials may focus either on a concrete technology or on a theoretical or mathematical tool. Ideally, tutorials will have a concrete result, such as "Learn to do X with Y" rather than "Learn language Y". Tutorials may occur in parallel to both ICFP and its co-located workshops, from September 23 through September 29. Additionally, ICFP is co-located with Strange Loop this year, and this will be taken into account when scheduling tutorials. ---------------------------------------------------------------------- Submission details Deadline for submission: April 9, 2018 Notification of acceptance: April 16, 2018 Prospective organizers of tutorials are invited to submit a completed tutorial proposal form in plain text format to the ICFP 2018 workshop co-chairs (Christophe Scholliers and David Christiansen), via email to icfp-workshops-2018(a)googlegroups.com by April 9, 2018. Please note that this is a firm deadline. Organizers will be notified if their event proposal is accepted by April 16, 2018. The proposal form is available at: http://www.icfpconference.org/icfp2018-files/icfp18-tutorials-form.txt ---------------------------------------------------------------------- Selection committee The proposals will be evaluated by a committee comprising the following members of the ICFP 2018 organizing committee. Workshop Co-Chair: Christophe Scholliers (University of Ghent) Workshop Co-Chair: David Christiansen (Galois, Inc.) General Chair: Robby Findler (Northwestern University) Program Chair: Matthew Flatt (University of Utah) ---------------------------------------------------------------------- Further information Any queries should be addressed to the workshop co-chairs (Christophe Scholliers and David Christiansen), via email to icfp-workshops-2018(a)googlegroups.com

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Call for Participation: <Programming> 2018 in Nice
by Sylvia Grewe 14 Mar '18

14 Mar '18

----------------------------------------------------------------------- <Programming> 2018 : The Art, Science, and Engineering of Programming April 9-12, 2018, Nice, France https://2018.programming-conference.org/ <https://2018.programming-conference.org> ----------------------------------------------------------------------- We are excited to welcome you to <Programming> 2018, the second edition of a young conference on everything to do with programming. It takes place at the Boscolo B4 Plaza in Nice, France on April 9-12. The <Programming> conference is closely associated with the open-access journal "The Art, Science, and Engineering of Programming". The journal's first two issues are freely accessible at http://programming-journal.org/ and form part of the conference's research track. Along with the research track, <Programming> 2018 features a program with two main keynotes, several workshops, a coding dojo, and a student research competition. *********************************************************************** Program highlights *********************************************************************** Main conference: - Keynote: "The Recurring Rainfall Problem" by Shriram Krishnamurthi - Keynote: "Static Analysis of Android Applications for Finding Bugs and Security Vulnerabilities" by Sukyoung Ryu Co-located events: - Bx 2018: Seventh International Workshop on Bidirectional Transformations, with 12 talks - MoreVMs 2018: Workshop on Modern Language Runtimes, Ecosystems, and VMs, with 9 talks - PASS 2018: Programming Across the System Stack, with 3 paper talks and two invited talks by Christa Lopes and Ludovic Henrio - PX/18: 4th Edition of the Programming Experience Workshop - ProWeb 2018: Programming Technology for the Future Web, with 4 paper talks and one invited talk by Manuel Serrano - Salon des Refusés 2018 workshop - CoCoDo 2018, Compiler Coding Dojo Social events: - Banquet at Restaurant of the Plage Beau Rivage (April 11) *********************************************************************** Registration, attendance and accommodation *********************************************************************** - You can register for <Programming> 2018 at: https://2018.programming-conference.org/attending/registration - Early registration ends soon! Please register before March 16th to obtain the early-bird discount. - More information on attending the conference is available at: https://2018.programming-conference.org/attending/reaching-the-conference - More information on accommodation is available at: https://2018.programming-conference.org/attending/accommodation <https://2018.programming-conference.org/attending/accomodation> *********************************************************************** About Nice *********************************************************************** Nice, Capital of the French Riviera, is a charming city between sea and mountains, which has a strong cultural heritage. You will discover the French gastronomy and specialities from Nice, the numerous museums (Musée Matisse, Musée des Arts Asiatiques, Musée des Beaux Arts, Musée d’Art Moderne et d’Art Contemporain (MAMAC), Musée Chagall…) and of course various places like “la promenade des Anglais” or “le Vieux Nice”. In “La Promenade des Anglais”, you may practice sports like running, roller skating or cycling, enjoy the beauty of the Meditterean Sea and spend some time on the beach. You can also walk downtown to do some shopping or just discover the city by using the Tramway which allows you to go about everywhere in Nice. There are many places to go out to enjoy your evenings in the Vieux Nice, around the harbor or downtown. ----------------------------------------------------------------------- For more information, please visit https://2018.programming-conference.org/ <https://2018.programming-conference.org> You can also find us on Twitter (twitter.com/programmingconf <http://twitter.com/programmingconf>) and Facebook (facebook.com/programmingconf <http://facebook.com/programmingconf>) Looking forward to seeing you in Nice, Manuel Serrano (General chair), Tamara Rezk (Organizing chair), Guido Salvaneschi (Program chair), Sylvia Grewe, Philipp Haller, Etienne Lozes, Stefan Marr, Minh Ngo, Tobias Pape, Yves Roudier, and Jennifer B. Sartor

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Gambit-list Mars 2018