January 2011 - Haskell

CfP: PPDP 2011
by mh＠informatik.uni-kiel.de 13 Jan '11

13 Jan '11

====================================================================== CALL FOR PAPERS PPDP 2011 13th International ACM SIGPLAN Symposium on Principles and Practice of Declarative Programming http://www-ps.informatik.uni-kiel.de/ppdp11/ July 20-22, 2011, Odense, Denmark (in cooperation with ACM SIGPLAN, co-located with LOPSTR 2011) ====================================================================== PPDP 2011 aims to provide a forum that brings together researchers from the declarative programming communities, including those working in the logic, constraint and functional programming paradigms, but also embracing a variety of other paradigms such as visual programming, executable specification languages, database languages, AI languages and knowledge representation languages used, for example, in the semantic web. The goal is to stimulate research in the use of logical formalisms and methods for specifying, performing, and analyzing computations, including mechanisms for mobility, modularity, concurrency, object-orientation, security, and static analysis. Papers related to the use of declarative paradigms and tools in industry and education are especially solicited. The conference will held in cooperation with ACM SIGPLAN and take place in July 2011 in Odense, Denmark, co-located with the 21st International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2011). TOPICS: - Logic, Constraint, and Functional Programming - Database, AI and Knowledge Representation Languages - Visual Programming - Executable Specification Languages - Applications of Declarative Programming - Methodologies: Program Design and Development - Declarative Aspects of Object-Oriented Programming - Concurrent Extensions to Declarative Languages - Declarative Mobile Computing - Integration of Paradigms - Proof Theoretic and Semantic Foundations - Type and Module Systems - Program Analysis and Verification - Program Transformation - Abstract Machines and Compilation - Programming Environments This list is not exhaustive - submissions describing new and interesting ideas relating broadly to declarative programming are encouraged. IMPORTANT DATES: Abstract submission: March 8, 2011 Paper submission: March 15, 2011 Notification: April 19, 2011 Camera-ready version: May 12, 2011 Symposium: July 20-22, 2011 SUBMISSION GUIDELINES: Papers should be submitted via the submission website for PPDP 2011: http://www.easychair.org/conferences/?conf=ppdp11 Papers must describe original work, be written and presented in English, and must not substantially overlap with papers that have been published or that are simultaneously submitted to a journal, conference, or workshop with refereed proceedings. Work that already appeared in unpublished or informally published workshop proceedings may be submitted (please contact the PC chair in case of questions). Papers should consist of the equivalent of 12 pages under the ACM formatting guidelines. These guidelines are available online, along with formatting templates or style files. Submitted papers will be judged on the basis of significance, relevance, correctness, originality, and clarity. They should include a clear identification of what has been accomplished and why it is significant. Authors who wish to provide additional material to the reviewers beyond the 12-page limit can do so in clearly marked appendices: reviewers are not required to read such appendices. PROCEEDINGS: The proceedings will be published by ACM Press. Authors of accepted papers will be required to sign a copyright form. PROGRAM COMMITTEE: Peter Achten Radboud University Nijmegen, The Netherlands Sergio Antoy Portland State University, USA Michael Codish Ben-Gurion University of the Negev, Israel Moreno Falaschi Universita di Siena, Italy Amy Felty University of Ottawa, Canada Michael Hanus University of Kiel, Germany (Chair) Andy King University of Kent, UK Helene Kirchner INRIA, France Francisco J. Lopez Fraguas Universidad Complutense de Madrid, Spain Salvador Lucas Universidad Politecnica de Valencia, Spain Simon Peyton Jones Microsoft Research, Cambridge, UK Kostis Sagonas Uppsala University, Sweden Peter Schneider-Kamp University of Southern Denmark, Denmark Doaitse Swierstra Utrecht University, The Netherlands Paul Tarau University of North Texas, USA Peter Thiemann University of Freiburg, Germany Kazunori Ueda Waseda University, Japan Tarmo Uustalu Tallinn University of Technology, Estonia Peter Van Roy Catholic University of Louvain, Belgium For more information, contact the chairs: Program Chair: Michael Hanus University of Kiel, Germany Email: mh(a)informatik.uni-kiel.de Symposium Chair: Peter Schneider-Kamp University of Southern Denmark Email: petersk(a)imada.sdu.dk ----------------------------------------------------------------------

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Haskell Weekly News: Issue 164 - January 12, 2011
by Daniel Santa Cruz 13 Jan '11

13 Jan '11

Welcome to issue 164 of the HWN, a newsletter covering developments in the [1]Haskell community. This release covers the week of January 2 to 8, 2011. Announcements Ben Millwood [2]announced the release of haskell-src-meta 0.3. He tells us that this release adds support for GHC 7, and for TH 2.5, along with other improvements. Mitar announced [3]a new version ef Etage, a general data-flow framework. Malcolm Wallace had [4]some news from the Haskell Language Committee. One of the points mentioned is that there will _not_ be a language standard called 2011, with the committee intending to issue a new language standard in 2012. Simon Peyton-Jones [5]invited members from the community to submit papers for the Workshop on Intermediate Representations 2011. The deadline is January 21. Clemens Grelck wanted to alert everyone that the [6]new deadline for papers for the Eighth International Workshop on Practical Aspects of High-Level Parallel Programming (PAPP 2011) to be held June 1-3, 2011, in Tsukuba, Japan. Emanuel Kitzelmann extended a [7]call for papers for the 4th International Workshop on Approaches and Applications of Inductive Programming (AAIP 2011) to be held July 19, 2011, in Odense, Denmark. Maciej Piechotka announced the [8]first release of nanoparsec. "Nanoparsec is currently simply a port of attoparsec on the ListLike--the abstraction of lists used by iteratee. Top Reddit Stories * Why Lisp is a Big Hack (And Haskell is Doomed to Succeed) Domain: axisofeval.blogspot.com, Score: 69, Comments: 15 On Reddit: http://www.reddit.com/r/haskell/comments/evbz5/why_lisp_is_a_big_hack_and_h… Original: http://axisofeval.blogspot.com/2011/01/why-lisp-is-big-hack-and-haskell-is.… * I ported Clojure's Persistent Vectors and Hash Maps to Haskell Domain: blog.wuwon.id.au, Score: 54, Comments: 2 On Reddit: http://www.reddit.com/r/haskell/comments/evzhz/i_ported_clojures_persistent… Original: http://blog.wuwon.id.au/2011/01/persistent-vectors-and-hash-maps-for.html * 3 Big Haskell Infrastructure Projects That Would Be Cool Domain: cdsmith.wordpress.com, Score: 31, Comments: 8 On Reddit: http://www.reddit.com/r/haskell/comments/evt56/3_big_haskell_infrastructure… Original: http://cdsmith.wordpress.com/2011/01/03/big-ideas-for-haskell/ * Merging binary and cereal Domain: blog.johantibell.com, Score: 31, Comments: On Reddit: http://www.reddit.com/r/haskell/comments/ewvpv/merging_binary_and_cereal/ Original: http://blog.johantibell.com/2011/01/merging-binary-and-cereal.html * Haskell library improvements I'd like to see Domain: blog.johantibell.com, Score: 28, Comments: On Reddit: http://www.reddit.com/r/haskell/comments/evm0g/haskell_library_improvements… Original: http://blog.johantibell.com/2011/01/haskell-library-improvements-id-like-to… * You can use GHC for the mac app store Domain: github.com, Score: 20, Comments: 8 On Reddit: http://www.reddit.com/r/haskell/comments/exxal/you_can_use_ghc_for_the_mac_… Original: https://github.com/nfjinjing/haskell-cocoa-currency-converter-example * Sudoku Solver in Haskell Domain: antimatroid.wordpress.com, Score: 18, Comments: 7 On Reddit: http://www.reddit.com/r/haskell/comments/ev1i0/sudoku_solver_in_haskell/ Original: http://antimatroid.wordpress.com/2009/06/01/sudoku-solver-in-haskell/ * Job Board for Functional Programmers Domain: functionaljobs.com, Score: 15, Comments: 6 On Reddit: http://www.reddit.com/r/haskell/comments/evi5d/job_board_for_functional_pro… Original: http://functionaljobs.com * Haskell library for analysis and synthesis of Go code. Domain: hackage.haskell.org, Score: 15, Comments: 6 On Reddit: http://www.reddit.com/r/haskell/comments/ex43z/haskell_library_for_analysis… Original: http://hackage.haskell.org/package/language-go * Hello Reddit! I implemented Levenshtein automata in Haskell after reading that 'Damn Cool Algorithm' blog post -- what do you think? Domain: self.haskell, Score: 14, Comments: 4 On Reddit: http://www.reddit.com/r/haskell/comments/ewl7o/hello_reddit_i_implemented_l… Original: /r/haskell/comments/ewl7o/hello_reddit_i_implemented_levenshtein_automata/ Top StackOverflow Questions * Why do we need 'seq' or 'pseq' with 'par' in Haskell? votes: 9, answers: 2 Read on SO: http://stackoverflow.com/questions/4576734/why-do-we-need-seq-or-pseq-with-… * Complex data structures in Haskell - how do they work? votes: 8, answers: 2 Read on SO: http://stackoverflow.com/questions/4597262/complex-data-structures-in-haske… * Mutability in functional programming votes: 8, answers: 3 Read on SO: http://stackoverflow.com/questions/4619500/mutability-in-functional-program… * Where can I learn advanced Haskell? votes: 8, answers: 6 Read on SO: http://stackoverflow.com/questions/4634962/where-can-i-learn-advanced-haske… * in haskell, why do I need to specify type constraints, why can't the compiler figure them out? votes: 7, answers: 4 Read on SO: http://stackoverflow.com/questions/4590975/in-haskell-why-do-i-need-to-spec… * Can someone explain to me the following Haskell expression votes: 6, answers: 2 Read on SO: http://stackoverflow.com/questions/4589957/can-someone-explain-to-me-the-fo… * Parse XML in Haskell votes: 6, answers: 5 Read on SO: http://stackoverflow.com/questions/4619206/parse-xml-in-haskell * Haskell: Record Update for Existential Types votes: 5, answers: 1 Read on SO: http://stackoverflow.com/questions/4580211/haskell-record-update-for-existe… * Are there any more original, more functional Haskell web-frameworks? votes: 5, answers: 2 Read on SO: http://stackoverflow.com/questions/4598091/are-there-any-more-original-more… * Defining a data type that doesn't want to be defined.. votes: 5, answers: 1 Read on SO: http://stackoverflow.com/questions/4612830/defining-a-data-type-that-doesnt… About the Haskell Weekly News You can find an html version of this newsletter at http://contemplatecode.blogspot.com/2011/01/haskell-weekly-news-issue-164.h… To help create new editions of this newsletter, please send stories to dstcruz(a)gmail.com. I'm in dire need of finding good "quotes of the week". If you happen to come across any, please don't hesitate to send it along. Hope your 2011 is off to a good start! Until next time, Daniel Santa Cruz References 1. http://haskell.org/ 2. http://permalink.gmane.org/gmane.comp.lang.haskell.general/18414 3. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/85062 4. http://article.gmane.org/gmane.comp.lang.haskell.general/18418 5. http://article.gmane.org/gmane.comp.lang.haskell.general/18415 6. http://article.gmane.org/gmane.comp.lang.haskell.general/18416 7. http://article.gmane.org/gmane.comp.lang.haskell.general/18417 8. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/85177

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LOPSTR 2011 - call for papers
by German Vidal 12 Jan '11

12 Jan '11

============================================================ Preliminary Call for papers 21th International Symposium on Logic-Based Program Synthesis and Transformation LOPSTR 2011 http://users.dsic.upv.es/~lopstr11/ Odense, Denmark, July 18-20, 2011 (co-located with PPDP 2011) ============================================================ Objectives: The aim of the LOPSTR series is to stimulate and promote international research and collaboration on logic-based program development. LOPSTR is open to contributions in logic-based program development in any language paradigm. LOPSTR has a reputation for being a lively, friendly forum for presenting and discussing work in progress. Formal proceedings are produced only after the symposium so that authors can incorporate this feedback in the published papers. The 21st International Symposium on Logic-based Program Synthesis and Transformation (LOPSTR 2011) will be held in Odense, Denmark; previous symposia were held in Hagenberg, Coimbra, Valencia, Lyngby, Venice, London, Verona, Uppsala, Madrid, Paphos, London, Venice, Manchester, Leuven, Stockholm, Arnhem, Pisa, Louvain-la-Neuve, and Manchester (you might have a look at the contents of past LOPSTR symposia). LOPSTR 2011 will be co-located with PPDP 2011 (International ACM SIGPLAN Symposium on Principles and Practice of Declarative Programming). Topics: Topics of interest cover all aspects of logic-based program development, all stages of the software life cycle, and issues of both programming- in-the-small and programming-in-the-large. Papers describing applications in these areas are especially welcome. Contributions are welcome on all aspects of logic-based program development, including, but not limited to: - specification - synthesis - verification - transformation - analysis - optimisation - specialization - partial evaluation - inversion - composition - program/model manipulation - certification - security - transformational techniques in SE - applications and tools Survey papers, that present some aspect of the above topics from a new perspective, and application papers, that describe experience with industrial applications, are also welcome. Papers must describe original work, be written and presented in English, and must not substantially overlap with papers that have been published or that are simultaneously submitted to a journal or a conference with refereed proceedings. Work that already appeared in unpublished or informally published workshops proceedings may be submitted. Following past editions, the formal post-conference proceedings are planned to be published by Springer-Verlag in the Lecture Notes in Computer Science (LNCS) series. IMPORTANT DATES AND SUBMISSION GUIDELINES: - Paper submission: March 27, 2011 - Extended abstract submission: April 3, 2011 - Notification (for pre-proceedings): May 16, 2011 - Camera-ready (for pre-proceedings): June 12, 2011 - Symposium: July 18-20, 2011 Submissions can either be (short) extended abstracts or (full) papers whose length should not exceed 9 and 15 pages (including references), respectively. Submissions must be formatted in the Lecture Notes in Computer Science style (excluding well-marked appendices not intended for publication). Referees are not required to read the appendices, and thus papers should be intelligible without them. Short papers may describe work-in-progress or tool demonstrations. Both short and full papers can be accepted for presentation at the symposium and will then appear in the LOPSTR 2011 pre-proceedings. Full papers can also be immediately accepted for publication in the formal proceedings, which is planned to be published by Springer-Verlag in the LNCS series. In addition, after the symposium, the programme committee will select further short or full papers presented in LOPSTR 2011 to be considered for formal publication. These authors will be invited to revise and/or extend their submissions in the light of the feedback solicited at the symposium. Then after another round of reviewing, these revised papers can also be published in the formal proceedings. Program Committee: TBD Contacts Program Chair (contact him for additional information about papers and submissions) German Vidal Department of Computer Science (DSIC) Universitat Politecnica de Valencia Valencia, Spain Email: lopstr11(a)dsic.upv.es General Chair Peter Schneider-Kamp Dept. of Mathematics and Computer Science University of Southern Denmark Campusvej 55 DK-5230 Odense M, Denmark Email: petersk(a)imada.sdu.dk

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Call for Papers (ICFEM 2011)
by Huibiao Zhu 12 Jan '11

12 Jan '11

************************************************************ ICFEM 2011 13th International Conference on Formal Engineering Methods *** FIRST CALL FOR PAPERS *** 25-28 Oct 2011 Radisson BLU Hotel, Durham, UK URL: http://www.scm.tees.ac.uk/icfem2011 ************************************************************ Since 1997, ICFEM has provided a forum for those interested in the application of formal engineering methods to computer systems.Researchers and practitioners, from industry, academia, and government, are encouraged to attend, and to help advance the state of the art. We are interested in work that has been incorporated into real production systems, and in theoretical work that promises to bring practical, tangible benefit. ICFEM 2011 is organised by Teesside University and will be held in the old historic Durham City in the North East of England (http://www.thisisdurham.com/) AREA AND TOPICS Submissions related to the following principal themes are encouraged, but any topics relevant to the field of formal methods and their support environments will also be considered: * Abstraction and refinement * Formal specification and modelling * Software verification * Program analysis * Software model checking * Formal approaches to software testing * Formal methods for object and component systems * Concurrency and software transaction memory * Formal methods for cloud computing * Software inspection * Formal methods for cyber-physical systems * Tool development and integration * Software safety, security and reliability * Experiments involving verified systems * Applications of formal methods * Formal model-based development and code generation SUBMISSION AND PUBLICATION Submissions to the conference must not have been published or be concurrently considered for publication elsewhere. All submissions will be judged on the basis of originality, contribution to the field, technical and presentation quality, and relevance to the conference. The proceedings will be published in the Springer Lecture Notes in Computer Science series. Papers should be written in English and not exceed 16 pages in LNCS format (see http://www.springer.de/comp/lncs/authors.html for details). Submission should be done through the ICFEM 2011 submission page (https://www.easychair.org/conferences/?conf=icfem2011) handled by the EasyChair conference system. All queries should be sent to the e-mail address icfem2011(a)scm.tees.ac.uk. IMPORTANT DATES 31 March, 2011: Abstract submission deadline 7 April, 2011: Full-paper submission deadline 8 June, 2011: Acceptance/rejection notification 6 July, 2011: Camera-ready version due ORGANIZATION COMMITTEE Honorary Chairs: Marc Cavazza, Teesside University Cliff Hardcastle, Teesside University General Chairs: Phil Brooke, Teesside University, UK Cliff Jones, Newcastle University, UK Program Chairs: Shengchao Qin, Teesside University, UK Zongyan Qiu, Peking University, UK Program Committee: Bernhard K. Aichernig (Graz University of Technology, Austria) Keijiro Araki (Kyushu University, Japan) Farhad Arbab (CWI and Leiden University, The Netherlands) Richard Banach (University of Manchester, UK) Nikolaj Bjorner (Microsoft Research Redmond, USA) Jonathan P. Bowen (University of Westminster, UK) Michael Butler (University of Southampton, UK) Andrew Butterfield (Trinity College Dublin, Ireland) Ana Cavalcanti (University of York, UK) Wei-Ngan Chin (National University of Singapore, Singapore) Florin Craciun (Soter Sys, Romania) Thao Dang (French National Center for Scientific Research, France) Jim Davies (Oxford University, UK) Dino Distefano (Queen Mary College, University of London, UK) Jin-Song Dong (National University of Singapore, Singapore) Zhenhua Duan (Xidian University, China) J. S. Fitzgerald (Newcastle University, UK) Leo Freitas (Newcastle University, UK) Joaquim Gabarro (Universitat Politècnica de Catalunya, Spain) Stefania Gnesi (ISTI-CNR, Italy) Anthony Hall (Consultant) Ian J. Hayes (The University of Queensland, Australia) Mike Hinchey (Lero, Ireland) Zhenjiang Hu (National Institute of Informatics, Japan) Michael Jackson (Consultant) Thierry Jéron (INRIA , France) Gerwin Klein (NICTA, Australia) Laura Kovacs (Vienna University of Technology, Austria) Kim G. Larsen (Aalborg University, Denmark) Peter Gorm Larsen (Aarhus University, Denmark) Michael Leuschel (Heinrich-Heine University Düsseldorf, Germany) Xuandong Li (Nanjing University, China) Shaoying Liu (Hosei University, Japan) Zhiming Liu (UNU/IIST, Macau) Tiziana Margaria (University of Potsdam, Germany) Stephan Merz (INRIA Nancy & LORIA, France) Huaikou Miao (Shanghai University, China) Peter Müller (ETH Zurich, Switzerland) Jun Pang (University of Luxembourg, Luxembourg) Matthew Parkinson (Microsoft Research Cambridge, UK) Geguang Pu (East China Normal University, China) Shengchao Qin (Teesside University, UK) Zongyan Qiu (Peking University, China) Augusto Sampaio (Universidade Federal de Pernambuco, Brazil) Thomas Santen (Microsoft Innovations Center Aachen, Germany) Wuwei Shen (Western Michigan University, USA) Marjan Sirjani (Reykjavik University, Iceland) Bill Stoddart (Teesside University, UK) Jing Sun (University of Auckland, New Zealand) Jun Sun (Singapore University of Technology and Design, Singapore) Kenji Taguchi (AIST, Japan) Tetsuo Tamai (University of Tokyo, Japan) Yih-Kuen Tsay (National Taiwan University, Taiwan) T.H. Tse (University of Hong Kong, Hong Kong) Viktor Vafeiadis (MPI-SWS, Germany) Miroslav Velev (Aries Design Automation, USA) Laurent Voisin (Systerel, France) Hai H. Wang (Aston University, UK) Ji Wang (National University of Defense Technology, China) Heike Wehrheim (University of Paderborn, Germany) Jim Woodcock (University of York, UK) Wang Yi (Uppsala University, Sweden) Naijun Zhan (Chinese Academy of Sciences, China) Jian Zhang (Chinese Academy of Sciences, China) Hong Zhu (Oxford Brookes University, UK) Huibiao Zhu (East China Normal University, China) Steering Committee Keijiro Araki, Japan Jin Song Dong, Singapore Chris George, Canada Jifeng He, China Mike Hinchey, Ireland Shaoying Liu (Chair), Japan John McDermid, UK Tetsuo Tamai, Japan Jim Woodcock, UK

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ANNOUNCE: haskell-src-exts 1.10.1
by Niklas Broberg 12 Jan '11

12 Jan '11

Fellow Haskelleers, I'm pleased to announce the release of haskell-src-exts-1.10.1! * On hackage: http://hackage.haskell.org/package/haskell-src-exts * Via cabal: cabal install haskell-src-exts * Darcs repo: http://code.haskell.org/haskell-src-exts Unless you are using the XmlSyntax extension, this major version bump should behave just like a minor version bump. Changes: 1.10.0 --> 1.10.1 =============== * Enable the unicode version of DoubleColon (x2237). Thanks to Andrés Sicard-Ramírez for the patch! 1.9.6 --> 1.10.0 =============== * Ensure that implied extensions are always picked up, not only when using the parseFile* family of functions as previously. * Add the newly devised <%>...</%> syntax to the XmlSyntax support. This causes changes to pretty much everything, including adding a case to the AST which prompts the major version bump. Cheers, /Niklas

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School of Expression pages missing from haskell.org
by Julian Gilbey 11 Jan '11

11 Jan '11

Does anyone know what has happened to the Haskell School of Expression (SOE) webpages? The link from books for learning Haskell now gives a 404 Not Found error. Thanks! Julian

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2nd CfP: JAL Special Issue on Automated Specification and Verification of Web Systems
by Temur Kutsia 11 Jan '11

11 Jan '11

[Apologies for multiple copies] ======================================================================== JOURNAL OF APPLIED LOGIC Special Issue on Automated Specification and Verification of Web Systems http://www.risc.uni-linz.ac.at/people/tkutsia/jal-wwv.html ======================================================================== SCOPE ----- This special issue of the Journal of Applied Logic is related to the topics of the workshop WWV'10: Automated Specification and Verification of Web Systems, which took place in Vienna on July 30-31, 2010. Both participants of the workshop and other authors are invited to submit contributions. The increased complexity of Web sites and the explosive growth of Web-based applications has turned their design and construction into a challenging problem. Nowadays, many companies have diverted their Web sites into interactive, completely-automated, Web-based applications (such as Amazon, on-line banking, or travel agencies) with a high complexity that requires appropriate specification and verification techniques and tools. Systematic, formal approaches to the analysis and verification can address the problems of this particular domain with automated and reliable tools that also incorporate semantic aspects. We solicit original papers on logic-based methods and techniques applied to Web sites, Web services or Web-based applications, such as: * Rule-based approaches to Web systems analysis, certification, specification, verification, and optimization * Algebraic methods for verification and certification of Web systems * Formal models for describing and reasoning about Web systems * Model-checking, synthesis and debugging of Web systems * Abstract interpretation and program transformation applied to the semantic Web * Intelligent tutoring and advisory systems for Web specifications authoring * Web quality and Web metrics * Web usability and accessibility * Testing and evaluation of Web systems and applications SUBMISSION ---------- We expect original articles (typically 15-25 pages; submission of larger papers will be evaluated depending on editorial constraints) that present high-quality contributions that have not been previously published and that must not be simultaneously submitted for publication elsewhere. Submissions must comply with JAL's author guidelines. They must be written in English and should be prepared using the Elsevier LaTeX package. Submissions are encouraged via the EasyChair submission system: http://www.easychair.org/conferences/?conf=jalwwv2010. IMPORTANT DATES --------------- * Submission of papers: March 7, 2011. * Notification: June 6, 2011. GUEST EDITORS -------------- * Laura Kovács (Vienna University of Technology) * Temur Kutsia (RISC, Johannes Kepler University Linz)

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Re: [Haskell] filesystem verification utility
by Anand Mitra 11 Jan '11

11 Jan '11

Based on feedback I inferred that the huge memory usage was mostly because of the String handling in the patern generation. To make it more efficient I have used Data.ByteString.Lazy.Char8 but now I get the following error when I execute stress: tmp/asdf-1: hPutBuf: illegal operation (handle is closed) stress: tmp/asdf-3: hPutBuf: illegal operation (handle is closed) stress: tmp/asdf-5: hPutBuf: illegal operation (handle is closed) stress: tmp/asdf-2: hPutBuf: illegal operation (handle is closed) stress: tmp/asdf-7: hPutBuf: illegal operation (handle is closed) stress: tmp/asdf-10: hPutBuf: illegal operation (handle is closed) I have explicitly remove all calls to close despite this I get this error. I tried both version of seek the fdSeek as well as hSeek. The documentation on hSeek had a confusing comment that "The offset i is given in terms of 8-bit bytes" At this point I am unable to understand how the handle is getting explicitly closed. {-# OPTIONS -fglasgow-exts #-} import Data.Int import qualified Data.ByteString.Lazy.Char8 as L import System.Random import Data.List import Monad import System.Posix.IO import System.Posix.Types import Data.Time.Clock import System.Posix.Files import Data.Maybe import GHC.IO.Device (SeekMode(..)) import Control.Exception import Data.Typeable import System import Control.Concurrent import System.IO --myrandomRlist :: (Num t, Random t) => t -> IO [t] --myrandomRlist x = liftM (randomRs (0,x)) newStdGen myrandomRlist :: (Num t, Random t) => t ->t -> StdGen -> [t] myrandomRlist min max seed = randomRs (min,max) seed data IoLoc = IoLoc {offset ::FileOffset, size::Int, num::Int } deriving (Show, Typeable) instance Exception IoLoc data Corrupt = Corrupt String IoLoc deriving (Show, Typeable) instance Exception Corrupt data FileHdr = FileHdr {fileName::FilePath, seed::StdGen, minIoSize::Int, maxIoSize::Int, ioCount::Int} deriving (Show) data FileIO = FileIO {fd::Handle, params::FileHdr, fileData::[IoLoc]} check hdl = do closed <- hIsClosed hdl if closed then do putStrLn $ "file handle was closed" ++ (show hdl) else do return () genPattern :: FilePath -> IoLoc -> L.ByteString genPattern f l = L.take (fromIntegral (size l)) (L.cycle $ L.pack ("(" ++ f ++ ")" ++ "[" ++ (show (offset l)) ++ ":" ++ (show (size l)) ++ (show (num l)) ++ "]")) doHdrRead :: Handle -> IO [Char] doHdrRead x = do fd <- handleToFd x (str, count) <- fdRead fd 100 return (takeWhile (\x-> not (x == '\n')) str) doGetHdr :: Handle -> IO FileHdr doGetHdr fd = do file <- doHdrRead fd seed <- doHdrRead fd minIoSize <- doHdrRead fd maxIoSize <- doHdrRead fd ioCount <- doHdrRead fd return (FileHdr file (read seed) (read minIoSize) (read maxIoSize) (read ioCount)) doHdrFromFile :: Handle -> IO FileIO doHdrFromFile fd = do -- fd <- openBinaryFile name ReadWriteMode -- (Just ownerModes) (OpenFileFlags {append=False, exclusive=False, noctty=True, nonBlock=False, trunc=False}) hSeek fd AbsoluteSeek 0 hdr <- doGetHdr fd return (FileIO fd hdr []) doHdrWrite :: Handle -> [Char] -> IO () doHdrWrite fd str = do hPutStr fd (take 100 (str ++ "\n" ++ (cycle ['\0']))) doWriteHdr :: Handle -> FileHdr -> IO () doWriteHdr fd hdr = do doHdrWrite fd (show (fileName hdr)) doHdrWrite fd (show (seed hdr)) doHdrWrite fd (show (minIoSize hdr)) doHdrWrite fd (show (maxIoSize hdr)) doHdrWrite fd (show (ioCount hdr)) doWriteFile :: FilePath -> IO FileIO doWriteFile name = do fd <- openBinaryFile name ReadWriteMode -- (Just ownerModes) (OpenFileFlags {append=False, exclusive=False, noctty=True, nonBlock=False, trunc=True}) seed <- newStdGen hdr <- return (FileHdr name seed 4096 (2*8096) 200) doWriteHdr fd hdr return (FileIO fd hdr []) overLap (IoLoc off1' sz1' num1) (IoLoc off2' sz2' num2) = ((off1 > off2) && (off1 < off2 +sz2)) ||((off1+sz1 >off2) &&(off1+sz1 < off2 +sz2)) where off1 = read (show off1') sz1 = read (show sz1') off2 = read (show off2') sz2 = read (show sz2') genIoList1 :: [IoLoc] -> [Int] -> [Int] -> Int -> Int -> [IoLoc] genIoList1 list offset size _ 0 = list genIoList1 list offset size 0 _ = list genIoList1 list (offset:os) (size:ss) count bound = if isNothing $ find (overLap x) list then genIoList1 ([x] ++ list) os ss (count - 1) (bound -1) else genIoList1 list os ss count (bound -1) where x = IoLoc (read (show offset)) (read(show size)) count -- offset = (read (show offset1)) -- size = (read(show size1)) genIoList :: FileHdr -> [IoLoc] genIoList (FileHdr name seed min max count) = genIoList1 [] (myrandomRlist 4000 1099511627776 seed) (myrandomRlist min max seed) count (count*2) doActualIo :: Handle -> IoLoc -> L.ByteString -> IO () doActualIo fd (IoLoc off sz num) str = do -- hSeek fd AbsoluteSeek off rfd <- (handleToFd fd) fdSeek rfd AbsoluteSeek off L.hPut fd str return () doVerifyIo :: Handle -> IoLoc -> L.ByteString -> IO () doVerifyIo fd (IoLoc off sz num) str = do -- hSeek fd AbsoluteSeek off rfd <- (handleToFd fd) fdSeek rfd AbsoluteSeek off filedata <- L.hGet fd sz if str == filedata then return () else throwIO (Corrupt ("Data corruption in #" ++ (take 200 (L.unpack str)) ++ "#" ++ (take 200 (L.unpack filedata)))(IoLoc off sz num)) mainWrite file = do (FileIO hd _ _) <- doWriteFile file hdrIO <- doHdrFromFile hd check hd (FileIO _ hdr _) <- return hdrIO check hd iolst <- return $ genIoList hdr app <- return $ zip iolst (map (genPattern (fileName hdr)) iolst) putStrLn (fileName hdr) mapM (\(x,y)-> doActualIo (fd hdrIO) x y) app mapM (\(x,y)-> doVerifyIo (fd hdrIO) x y) app -- hClose hd return hdr mainVerify file = do hd <- openBinaryFile file ReadWriteMode hdrIO <- doHdrFromFile hd hdr <- return (params hdrIO) iolst <- return $ genIoList hdr file <- return $ filter (\x->not ( x=='"')) (fileName hdr) app <- return $ zip iolst (map (genPattern file) iolst) putStrLn $ filter (\x->not ( x=='"')) (fileName hdr) mapM (\(x,y)-> doVerifyIo (fd hdrIO) x y) app -- hClose hd return hdr main = do x <- getArgs if (length x) == 3 then do main1 else do putStrLn "USAGE:\nfile-io write/verify <full-path file name> <number of threads> \ \\n\n\ \Simple IO load generator with write verification. This utility is designed\n\ \to generate multi-threaded IO load which will write a pattern to the file. \n\ \When this is invoked with the same parameters with the verify option \n\ \the data written will be verified.\n\ \ " main1 = do [op, name, numProcs] <- getArgs m <- newEmptyMVar n <- return $read numProcs case op of "write" -> do mapM forkIO [(fillfile (name ++ (show i)) ) m|i<-[1..n]] "verify" -> do mapM forkIO [(verifyfile (name ++ (show i)) ) m|i<-[1..n]] x <- mapM takeMVar $ take (read numProcs) $ repeat m putStrLn $ show $ and x fillfile filename m = do mainWrite filename putMVar m True verifyfile filename m = do mainVerify filename putMVar m True On Tue, Jan 11, 2011 at 1:02 AM, Anand Mitra <mitra(a)kqinfotech.com> wrote: > Hi, > > I had a requirement to generate various kinds of I/O patterns on a > filesystem and subsequently verify this. The initial version of the > program below implements a random I/O pattern with multiple threads. > Even when the number of I/O is as small as 200 and 10 concurrent > theads, the amount of memory used is huge. When I run the program it > consumes close to 1to2GB memory. Moreover the rate at which it > generates the I/O is very low which is not good for testing a > filesystem. I have used System.POSIX.IO but I tried System.IO and did > not see much difference either. I would appreciate help in identifying > ways to improve this. > >

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filesystem verification utility
by Anand Mitra 11 Jan '11

11 Jan '11

Hi, I had a requirement to generate various kinds of I/O patterns on a filesystem and subsequently verify this. The initial version of the program below implements a random I/O pattern with multiple threads. Even when the number of I/O is as small as 200 and 10 concurrent theads, the amount of memory used is huge. When I run the program it consumes close to 1to2GB memory. Moreover the rate at which it generates the I/O is very low which is not good for testing a filesystem. I have used System.POSIX.IO but I tried System.IO and did not see much difference either. I would appreciate help in identifying ways to improve this. {-# OPTIONS -fglasgow-exts #-} import System.Random import Data.List import Monad import System.Posix.IO import System.Posix.Types import Data.Time.Clock import System.Posix.Files import Data.Maybe import GHC.IO.Device (SeekMode(..)) import Control.Exception import Data.Typeable import System import Control.Concurrent --myrandomRlist :: (Num t, Random t) => t -> IO [t] --myrandomRlist x = liftM (randomRs (0,x)) newStdGen myrandomRlist :: (Num t, Random t) => t ->t -> StdGen -> [t] myrandomRlist min max seed = randomRs (min,max) seed data IoLoc = IoLoc {offset :: FileOffset, size::ByteCount, num::Int } deriving (Show, Typeable) instance Exception IoLoc data Corrupt = Corrupt String IoLoc deriving (Show, Typeable) instance Exception Corrupt data FileHdr = FileHdr {fileName::FilePath, seed::StdGen, minIoSize::Int, maxIoSize::Int, ioCount::Int} deriving (Show) data FileIO = FileIO {fd::Fd, params::FileHdr, fileData::[IoLoc]} genPattern :: FilePath -> IoLoc -> String genPattern f l = take (read $ show $size l) (cycle $ "(" ++ f ++ ")" ++ "[" ++ (show (offset l)) ++ ":" ++ (show (size l)) ++ (show (num l)) ++ "]") doHdrRead :: Fd -> IO [Char] doHdrRead fd = do (str, count) <- fdRead fd 100 return (takeWhile (\x-> not (x == '\n')) str) doGetHdr :: Fd -> IO FileHdr doGetHdr fd = do file <- doHdrRead fd seed <- doHdrRead fd minIoSize <- doHdrRead fd maxIoSize <- doHdrRead fd ioCount <- doHdrRead fd return (FileHdr file (read seed) (read minIoSize) (read maxIoSize) (read ioCount)) doHdrFromFile :: FilePath -> IO FileIO doHdrFromFile name = do fd <- openFd name ReadWrite (Just ownerModes) (OpenFileFlags {append=False, exclusive=False, noctty=True, nonBlock=False, trunc=False}) hdr <- doGetHdr fd return (FileIO fd hdr []) doHdrWrite :: Fd -> [Char] -> IO ByteCount doHdrWrite fd str = do fdWrite fd (take 100 (str ++ "\n" ++ (cycle ['\0']))) doWriteHdr :: Fd -> FileHdr -> IO ByteCount doWriteHdr fd hdr = do doHdrWrite fd (show (fileName hdr)) doHdrWrite fd (show (seed hdr)) doHdrWrite fd (show (minIoSize hdr)) doHdrWrite fd (show (maxIoSize hdr)) doHdrWrite fd (show (ioCount hdr)) doWriteFile :: FilePath -> IO FileHdr doWriteFile name = do fd <- openFd name ReadWrite (Just ownerModes) (OpenFileFlags {append=False, exclusive=False, noctty=True, nonBlock=False, trunc=True}) seed <- newStdGen hdr <- return (FileHdr name seed 4096 (2*8096) 200) doWriteHdr fd hdr return hdr overLap (IoLoc off1' sz1' num1) (IoLoc off2' sz2' num2) = ((off1 > off2) && (off1 < off2 +sz2)) ||((off1+sz1 >off2) &&(off1+sz1 < off2 +sz2)) where off1 = read (show off1') sz1 = read (show sz1') off2 = read (show off2') sz2 = read (show sz2') genIoList1 :: [IoLoc] -> [Int] -> [Int] -> Int -> Int -> [IoLoc] genIoList1 list offset size _ 0 = list genIoList1 list offset size 0 _ = list genIoList1 list (offset:os) (size:ss) count bound = if isNothing $ find (overLap x) list then genIoList1 ([x] ++ list) os ss (count - 1) (bound -1) else genIoList1 list os ss count (bound -1) where x = IoLoc (read (show offset)) (read(show size)) count -- offset = (read (show offset1)) -- size = (read(show size1)) genIoList :: FileHdr -> [IoLoc] genIoList (FileHdr name seed min max count) = genIoList1 [] (myrandomRlist 4000 1099511627776 seed) (myrandomRlist min max seed) count (count*2) doActualIo :: Fd -> IoLoc -> String -> IO () doActualIo fd (IoLoc off sz num) str = do off <- fdSeek fd AbsoluteSeek off fdWrite fd str return () doVerifyIo :: Fd -> IoLoc -> String -> IO () doVerifyIo fd (IoLoc off sz num) str = do off <- fdSeek fd AbsoluteSeek off (filedata, count) <- fdRead fd sz if str == filedata then return () else throwIO (Corrupt ("Data corruption in #" ++ (take 200 str) ++ "#" ++ (take 200 filedata))(IoLoc off sz num)) mainWrite file = do hdr <- doWriteFile file hdrIO <- doHdrFromFile file iolst <- return $ genIoList hdr app <- return $ zip iolst (map (genPattern (fileName hdr)) iolst) putStrLn (fileName hdr) mapM (\(x,y)-> doActualIo (fd hdrIO) x y) app mapM (\(x,y)-> doVerifyIo (fd hdrIO) x y) app return hdr mainVerify file = do hdrIO <- doHdrFromFile file hdr <- return (params hdrIO) iolst <- return $ genIoList hdr file <- return $ filter (\x->not ( x=='"')) (fileName hdr) app <- return $ zip iolst (map (genPattern file) iolst) putStrLn $ filter (\x->not ( x=='"')) (fileName hdr) mapM (\(x,y)-> doVerifyIo (fd hdrIO) x y) app return hdr main = do x <- getArgs if (length x) == 3 then do main1 else do putStrLn "USAGE:\nfile-io write/verify <full-path file name> <number of threads> \ \\n\n\ \Simple IO load generator with write verification. This utility is designed\n\ \to generate multi-threaded IO load which will write a pattern to the file. \n\ \When this is invoked with the same parameters with the verify option \n\ \the data written will be verified.\n\ \ " main1 = do [op, name, numProcs] <- getArgs m <- newEmptyMVar n <- return $read numProcs case op of "write" -> do mapM forkIO [(fillfile (name ++ (show i)) ) m|i<-[1..n]] "verify" -> do mapM forkIO [(verifyfile (name ++ (show i)) ) m|i<-[1..n]] x <- mapM takeMVar $ take (read numProcs) $ repeat m putStrLn $ show $ and x fillfile filename m = do mainWrite filename putMVar m True verifyfile filename m = do mainVerify filename putMVar m True

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ANNOUNCE: Monad.Reader Issue 17
by Brent Yorgey 09 Jan '11

09 Jan '11

I am pleased to announce that Issue 17 of The Monad.Reader is now available [1]. Issue 17 consists of the following three articles: * List Leads Off with the Letter Lambda by Douglas M. Auclair * The InterleaveT Abstraction: Alternative with Flexible Ordering by Neil Brown * The Reader Monad and Abstraction Elimination by Petr Pudlak Feel free to browse the source files [2]. You can check out the entire repository using darcs: darcs get http://code.haskell.org/~byorgey/TMR/Issue17 Watch for a special announcement regarding Issue 18 soon! [1] http://themonadreader.files.wordpress.com/2011/01/issue17.pdf [2] http://code.haskell.org/~byorgey/TMR/Issue17

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