Search Results

Search found 913 results on 37 pages for 'haskell multicore'.

Page 28/37 | < Previous Page | 24 25 26 27 28 29 30 31 32 33 34 35  | Next Page >

  • A Method for Reducing Contention and Overhead in Worker Queues for Multithreaded Java Applications

    - by Janice J. Heiss
    A java.net article, rich in practical resources, by IBM India Labs’ Sathiskumar Palaniappan, Kavitha Varadarajan, and Jayashree Viswanathan, explores the challenge of writing code in a way that that effectively makes use of the resources of modern multicore processors and multiprocessor servers.As the article states: “Many server applications, such as Web servers, application servers, database servers, file servers, and mail servers, maintain worker queues and thread pools to handle large numbers of short tasks that arrive from remote sources. In general, a ‘worker queue’ holds all the short tasks that need to be executed, and the threads in the thread pool retrieve the tasks from the worker queue and complete the tasks. Since multiple threads act on the worker queue, adding tasks to and deleting tasks from the worker queue needs to be synchronized, which introduces contention in the worker queue.” The article goes on to explain ways that developers can reduce contention by maintaining one queue per thread. It also demonstrates a work-stealing technique that helps in effectively utilizing the CPU in multicore systems. Read the rest of the article here.

    Read the article

  • Catching Up with Lisp

    Support for multicore and Big Data are among the upcoming features of Franz's Lisp-based tools Lisp - Programming - Languages - FAQs Help and Tutorials - Compilers and Interpreters

    Read the article

  • Programming concepts taken from the arts and humanities

    - by Joey Adams
    After reading Paul Graham's essay Hackers and Painters and Joel Spolsky's Advice for Computer Science College Students, I think I've finally gotten it through my thick skull that I should not be loath to work hard in academic courses that aren't "programming" or "computer science" courses. To quote the former: I've found that the best sources of ideas are not the other fields that have the word "computer" in their names, but the other fields inhabited by makers. Painting has been a much richer source of ideas than the theory of computation. — Paul Graham, "Hackers and Painters" There are certainly other, much stronger reasons to work hard in the "boring" classes. However, it'd also be neat to know that these classes may someday inspire me in programming. My question is: what are some specific examples where ideas from literature, art, humanities, philosophy, and other fields made their way into programming? In particular, ideas that weren't obviously applied the way they were meant to (like most math and domain-specific knowledge), but instead gave utterance or inspiration to a program's design and choice of names. Good examples: The term endian comes from Gulliver's Travels by Tom Swift (see here), where it refers to the trivial matter of which side people crack open their eggs. The terms journal and transaction refer to nearly identical concepts in both filesystem design and double-entry bookkeeping (financial accounting). mkfs.ext2 even says: Writing superblocks and filesystem accounting information: done Off-topic: Learning to write English well is important, as it enables a programmer to document and evangelize his/her software, as well as appear competent to other programmers online. Trigonometry is used in 2D and 3D games to implement rotation and direction aspects. Knowing finance will come in handy if you want to write an accounting package. Knowing XYZ will come in handy if you want to write an XYZ package. Arguably on-topic: The Monad class in Haskell is based on a concept by the same name from category theory. Actually, Monads in Haskell are monads in the category of Haskell types and functions. Whatever that means...

    Read the article

  • Why do I not get the correct answer for Euler 56 in J?

    - by Gregory Higley
    I've solved 84 of the Project Euler problems, mostly in Haskell. I am now going back and trying to solve in J some of those I already solved in Haskell, as an exercise in learning J. Currently, I am trying to solve Problem 56. Let me stress that I already know what the right answer is, since I've already solved it in Haskell. It's a very easy, trivial problem. I will not give the answer here. Here is my solution in J: digits =: ("."0)":"0 eachDigit =: adverb : 'u@:digits"0' NB. I use this so often I made it an adverb. cartesian =: adverb : '((#~ #) u ($~ ([:*~#)))' >./ +/ eachDigit x: ^ cartesian : i. 99 This produces a number less than the desired result. In other words, it's wrong somehow. Any J-ers out there know why? I'm baffled, since it's pretty straightforward and totally brute force.

    Read the article

  • Performance affects of compressing Program Files on Windows / NTFS

    - by SRobertJames
    What are the performance affects of compressing Program Files on Windows NTFS? On a fast, multicore machine, the overhead of decompression is minimal. Machines are generally disk bound, and if you can reduce the disk load by compression, you often speed things up. (Microsoft says that the built in compression of Windows Search indexes actually improves speed for this reason.) On the other hand, Windows' virtual memory is complicated. Perhaps if files are compressed, they can't be paged out simply. And there may be other issues. In short: On a fast, multicore machine with a relatively slow disk, what performance affects will compressing Program Files have?

    Read the article

  • The Cloud is STILL too slow!

    - by harry.foxwell(at)oracle.com
    If you've been in the computing industry sufficiently long enough to remember dialup modems and other "ancient" technologies, you might be tempted to marvel at today's wonderfully powerful multicore PCs, ginormous disks, and blazingly fast networks.  Wow, you're in Internet Nirvana, right!  Well, no, not by a long shot.Considering the exponentially growing expectations of what the Web, that is, "the Cloud", is supposed to provide, today's Web/Cloud services are still way too slow.Already we are seeing cloud-enabled consumer devices that are stressing even the most advanced public network services.  Like the iPad and its competitors, ever more powerful smart-phones, and an imminent hoard of special purpose gadgets such as the proposed "cloud camera" (see http://gdgt.com/discuss/it-time-cloud-camera-found-out-cnr/ ).And at the same time that the number and type of cloud services are growing, user tolerance for even the slightest of download delays is rapidly decreasing.  Ten years ago Web developers followed the "8-Second Rule", (average time a typical Web user would tolerate for a page to download and render).  Not anymore; now it's less than 3 seconds, and only a bit longer for mobile devices (see http://www.technologyreview.com/files/54902/GoogleSpeed_charts.pdf).  How spoiled we've become!Google, among others, recognizes this problem and is working to encourage the development of a faster Web (see http://www.technologyreview.com/web/32338/). They, along with their competitors and ISPs, will have to encourage and support significantly better Web performance in order to provide the types of services envisioned for the Cloud.  How will they do this? Through the development of faster components, better use of caching technologies, and the really tough one - exploiting parallelism. Not that parallel technologies like multicore processors are hard to build...we already have them.  It's just that we're not that good yet at using them effectively.  And if we don't get better, users will abandon cloud-based services...in less than 3 seconds.

    Read the article

  • What is the best way to exploit multicores when making multithread games?

    - by Keeper
    Many people suggest to write a program, and then start optimizing it. But I think that when it's coming to multithreading with multicore, a little think ahead is required. I've read about using threads, and experienced it myself during some courses at the university (still a student). The big question is simple, but a bit abstract: What thread related steps in game design do I need to take, before implementation? Now trying to be more specific. Let's say, as an example, that I'm making a small board game (like Monopoly) that I want to be multithreaded. My goal Is that this multithreaded game will exploit the best of the multicore system, lets say 4-6 cores (like in i7 processors). My answer to this question at the moment is, one thread for each of these four basic components: GUI User Input / Output AI (computer rival) Other game related calculations (like shortest path from A to B, or level up status change) I'm not an expert (yet!), and I'm sure there are better answers out there. Any suggestion, answer, different approach will be helpful. Some thoughts: Maybe splitting the main database is a good way.. (or total disaster.. )

    Read the article

  • Learning functional programming [closed]

    - by Oni
    This question is similar to Choosing a functional programming language. I want to learn functional programming but I am having troubles choosing the right programming language. At the university I studied Haskell for 2 months, so I have a basic idea of what a functional language is. I have read a lot that functional programming change your way of think. I started to take a look to Clojure, which I like for several reasons(code as data, JVM, etc). What stops me from continue learning Clojure is that it is not a pure functional language and I am afraid of ending up using imperative/OO style. Should I learn Haskell or keep on learning Clojure? Thanks in advance P.D: I am open to any other language.

    Read the article

  • Are C or C++ The Only Viable Languages for a GC

    - by user95312
    Background I have just finished writing a compiler for a functional language compiling to the JVM as a learning project. However, since I'm just doing this to learn, I thought it might be interesting to write a native backend and a RTS for it. As I've been planning out what this new backend will look like, the one point I'm stumbling on is the garbage collector. I've implemented the compiler in Haskell. But I have no desire to write the GC in Haskell since, while it may be possible, it'd suck. Question I've looked at several FOSS garbage collectors prior to posting and most of them were implemented in good old ANSI C. Is this still the most accepted choice for writing a GC nowadays? I've seen that this site tends to frown upon questions with multiple answers so I hope this will make it more specific: If some startup was writing a professional grade gc today, are the only viable choice for them C or C++? It's my first question here so please comment and let me know if this question is ill-suited for for programmers.

    Read the article

  • Languages with C/C++ output [closed]

    - by Vag
    Which languages have compilers able to emit plain standard C/C++ code? For a start: Haxe // uses Boehm GC Haskell (JHC) Haskell (old GHC) // -fvia-c, removed recently (emitted code is super ugly) Clay ATS Cython RPython (Shed Skin) // experimental RPython (PyPy) Python (Nuitka) // although author claims there are no speedups Common Lisp (ECL) COBOL (OpenCobol) Scheme (Chicken) APL // So far I've not found working implementation available for free download Ur/Web // GCC-specific output, and intended to be used only for web developments (included for completeness only) I'd like to build comprehensive up-to-date list but found only these ones so far. I've tested only Haxe and it works pretty well and quite fast. What about other ones? What is your expirience? How much ugly is generated code? Update. Any language chains (e.g. X - Scheme - C) will be perfectly OK as answer if its use is practical enough and suited for production use.

    Read the article

  • Manual memory allocation and purity

    - by Eonil
    Language like Haskell have concept of purity. In pure function, I can't mutate any state globally. Anyway Haskell fully abstracts memory management, so memory allocation is not a problem here. But if languages can handle memory directly like C++, it's very ambiguous to me. In these languages, memory allocation makes visible mutation. But if I treat making new object as impure action, actually, almost nothing can be pure. So purity concept becomes almost useless. How should I handle purity in languages have memory as visible global object?

    Read the article

  • Parallel task in C# 4.0

    - by Jalpesh P. Vadgama
    In today’s computing world the world is all about Parallel processing. You have multicore CPU where you have different core doing different work parallel or its doing same task parallel. For example I am having 4-core CPU as follows. So the code that I write should take care of this.C# does provide that kind of facility to write code for multi core CPU with task parallel library. We will explore that in this post. Read More

    Read the article

  • Are functional programming languages good for practical tasks?

    - by Clueless
    It seems to me from my experimenting with Haskell, Erlang and Scheme that functional programming languages are a fantastic way to answer scientific questions. For example, taking a small set of data and performing some extensive analysis on it to return a significant answer. It's great for working through some tough Project Euler questions or trying out the Google Code Jam in an original way. At the same time it seems that by their very nature, they are more suited to finding analytical solutions than actually performing practical tasks. I noticed this most strongly in Haskell, where everything is evaluated lazily and your whole program boils down to one giant analytical solution for some given data that you either hard-code into the program or tack on messily through Haskell's limited IO capabilities. Basically, the tasks I would call 'practical' such as Aceept a request, find and process requested data, and return it formatted as needed seem to translate much more directly into procedural languages. The most luck I have had finding a functional language that works like this is Factor, which I would liken to a reverse-polish-notation version of Python. So I am just curious whether I have missed something in these languages or I am just way off the ball in how I ask this question. Does anyone have examples of functional languages that are great at performing practical tasks or practical tasks that are best performed by functional languages?

    Read the article

  • Advice for a computer science sophomore in college?

    - by RDas
    Hi Everyone! I'm a sophomore in college majoring in Computer Science and Math. I have always loved programming. I started programming in C when I was nine years old and over the years I've picked up Visual Basic, C#, Java, C++, JavaScript, Objective-C, Python, Ruby, elementary Haskell and elementary Erlang, and I learned Perl back in the day which I've mostly forgotten. I have not done much network programming. I have done CGI programming, but that was about six/seven years ago. I've done some socket programming and written (school) programs to do interprocess communication, which I understood and liked. I'm taking a course on client/server programming and another one on network security next semester, which I am really looking forward to. I'm seeking advice on how to proceed with future learning. I've mostly done application (mobile and desktop) development, not much of web development. I'd like to pick up some web development this coming semester. Since I know Ruby and Python, should I start by learning Django and/or Rails? Any other suggestions on starting web development? I have a good understanding of HTML and CSS. Also, I'd also like to know how hard it is to pick up and be good (read: productive) in functional programming languages coming from a purely structured/object oriented background? I've been reading up on Erlang and Haskell, and I'd like to know your opinions on whether it's worth my time trying to learn them. What about Lisp, Scheme and other functional languages? Any help/ideas would be really appreciated.

    Read the article

  • Is there a modified LGPL license that allows static linking?

    - by Petr Pudlák
    úLGPL requires that it if a program uses LGPL-ed library, users must be able to re-link the program with a different version of the library: ... d) Do one of the following: 0) Convey the Minimal Corresponding Source under the terms of this License, and the Corresponding Application Code in a form suitable for, and under terms that permit, the user to recombine or relink the Application with a modified version of the Linked Version to produce a modified Combined Work, in the manner specified by section 6 of the GNU GPL for conveying Corresponding Source. 1) Use a suitable shared library mechanism for linking with the Library. A suitable mechanism is one that (a) uses at run time a copy of the Library already present on the user's computer system, and (b) will operate properly with a modified version of the Library that is interface-compatible with the Linked Version. ... However in some cases, this can pose considerable difficulties. In particular, Haskell programs are almost always statically compiled. Moreover, the compiler does cross-module optimizations so it's very hard to satisfy this condition. (See this link at Haskell Wiki.) Therefore, I'm looking for a standard LGPL-like license that wouldn't require the possibility of re-linking. Some projects use their own modification of LGPL, for example wxWidgets. But I'd rather use some standard license that is somewhat more official, perhaps checked by some law experts, and (L)GPL compatible. Is there some like that? (Also I'd be interested to know if are there some unforeseen consequences of such a modification of LGPL.)

    Read the article

  • Why am I not getting an sRGB default framebuffer?

    - by Aaron Rotenberg
    I'm trying to make my OpenGL Haskell program gamma correct by making appropriate use of sRGB framebuffers and textures, but I'm running into issues making the default framebuffer sRGB. Consider the following Haskell program, compiled for 32-bit Windows using GHC and linked against 32-bit freeglut: import Foreign.Marshal.Alloc(alloca) import Foreign.Ptr(Ptr) import Foreign.Storable(Storable, peek) import Graphics.Rendering.OpenGL.Raw import qualified Graphics.UI.GLUT as GLUT import Graphics.UI.GLUT(($=)) main :: IO () main = do (_progName, _args) <- GLUT.getArgsAndInitialize GLUT.initialDisplayMode $= [GLUT.SRGBMode] _window <- GLUT.createWindow "sRGB Test" -- To prove that I actually have freeglut working correctly. -- This will fail at runtime under classic GLUT. GLUT.closeCallback $= Just (return ()) glEnable gl_FRAMEBUFFER_SRGB colorEncoding <- allocaOut $ glGetFramebufferAttachmentParameteriv gl_FRAMEBUFFER gl_FRONT_LEFT gl_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING print colorEncoding allocaOut :: Storable a => (Ptr a -> IO b) -> IO a allocaOut f = alloca $ \ptr -> do f ptr peek ptr On my desktop (Windows 8 64-bit with a GeForce GTX 760 graphics card) this program outputs 9729, a.k.a. gl_LINEAR, indicating that the default framebuffer is using linear color space, even though I explicitly requested an sRGB window. This is reflected in the rendering results of the actual program I'm trying to write - everything looks washed out because my linear color values aren't being converted to sRGB before being written to the framebuffer. On the other hand, on my laptop (Windows 7 64-bit with an Intel graphics chip), the program prints 0 (huh?) and I get an sRGB default framebuffer by default whether I request one or not! And on both machines, if I manually create a non-default framebuffer bound to an sRGB texture, the program correctly prints 35904, a.k.a. gl_SRGB. Why am I getting different results on different hardware? Am I doing something wrong? How can I get an sRGB framebuffer consistently on all hardware and target OSes?

    Read the article

  • Tmux causes Emacs glitch

    - by killy9999
    Recently I started using Tmux, but I noticed that it causes a strange Emacs glitch. When I open source code for elisp or haskell, the comments aren't highlighted. Only the comment sign is (; in case of elisp, -- in case of haskell). The rest of the commented line is in normal colour. When I run Emacs outside of Tmux everything works as expected - the whole commented line is highlighted in a colour denoting a comment. Any ideas why this is happening? SOLUTION: Based on Stefan's comment I added this to my .emacs file: (custom-set-variables (custom-set-faces '(font-lock-comment-face ((((class color) (min-colors 8) (background dark)) (:foreground "red")))))) Now the comments are displayed in red, just like comment delimiters.

    Read the article

  • Thoughts on type aliases/synonyms?

    - by Rei Miyasaka
    I'm going to try my best to frame this question in a way that doesn't result in a language war or list, because I think there could be a good, technical answer to this question. Different languages support type aliases to varying degrees. C# allows type aliases to be declared at the beginning of each code file, and they're valid only throughout that file. Languages like ML/Haskell use type aliases probably as much as they use type definitions. C/C++ are sort of a Wild West, with typedef and #define often being used seemingly interchangeably to alias types. The upsides of type aliasing don't invoke too much dispute: It makes it convenient to define composite types that are described naturally by the language, e.g. type Coordinate = float * float or type String = [Char]. Long names can be shortened: using DSBA = System.Diagnostics.DebuggerStepBoundaryAttribute. In languages like ML or Haskell, where function parameters often don't have names, type aliases provide a semblance of self-documentation. The downside is a bit more iffy: aliases can proliferate, making it difficult to read and understand code or to learn a platform. The Win32 API is a good example, with its DWORD = int and its HINSTANCE = HANDLE = void* and its LPHANDLE = HANDLE FAR* and such. In all of these cases it hardly makes any sense to distinguish between a HANDLE and a void pointer or a DWORD and an integer etc.. Setting aside the philosophical debate of whether a king should give complete freedom to their subjects and let them be responsible for themselves or whether they should have all of their questionable actions intervened, could there be a happy medium that would allow the benefits of type aliasing while mitigating the risk of its abuse? As an example, the issue of long names can be solved by good autocomplete features. Visual Studio 2010 for instance will alllow you to type DSBA in order to refer Intellisense to System.Diagnostics.DebuggerStepBoundaryAttribute. Could there be other features that would provide the other benefits of type aliasing more safely?

    Read the article

  • How are objects modelled in a functional programming language?

    - by Giorgio
    In an answer to this question (written by Pete) there are some considerations about OOP versus FP. In particular, it is suggested that FP languages are not very suitable for modelling (persistent) objects that have an identity and a mutable state. I was wondering if this is true or, in other words, how one would model objects in a functional programming language. From my basic knowledge of Haskell I thought that one could use monads in some way, but I really do not know enough on this topic to come up with a clear answer. So, how are entities with an identity and a mutable persistent state normally modelled in a functional language? EDIT Here are some further details to clarify what I have in mind. Take a typical Java application in which I can (1) read a record from a database table into a Java object, (2) modify the object in different ways, (3) save the modified object to the database. How would this be implemented e.g. in Haskell? I would initially read the record into a record value (defined by a data definition), perform different transformations by applying functions to this initial value (each intermediate value is a new, modified copy of the original record) and then write the final record value to the database. Is this all there is to it? How can I ensure that at each moment in time only one copy of the record is valid / accessible? One does not want to have different immutable values representing different snapshots of the same object to be accessible at the same time.

    Read the article

  • Windows 7 PATH not expanding

    - by trinithis
    I am using the following to create and edit environment variables for Windows 7. Control Panel\All Control Panel Items\System -> Advanced system settings -> Environment Variables Under System variables I have the following pertinant variables: PROG32=C:\Program Files (x86) REALDWG_SDK_DIR=%PROG32%\Autodesk\RealDWG 2011 Path=%REALDWG_SDK_DIR%;%PROG32%\Haskell\bin However, the following happens: C:\>echo %PROG32% C:\Program Files (x86) C:\>echo %Path% %REALDWG_SDK_DIR%;C:\Program Files (x86)\Haskell\bin Is it possible to have a chain of variables expand? If I rename Path to something else, I sometimes get the problem, and sometimes I don't.

    Read the article

  • How much sense does it make for a veteran .Net developer to move to ROR professionally?

    - by SharePoint Newbie
    Hi, I consider myself a moderately skilled (definitely not stupid) .Net developer. Over the past 5 years I've been working with ASP.Net, ASP.Net MVC, SharePoint, WPF, Silverlight, RDBMS (SQL Server and Oracle). I maintain/contribute a couple of .Net OSS. I've also picked up F# and Haskell over the previous year. I am currently employed at one of the better (best) software firms out there and would surely love to continue working here. However over the past 6 months opportunities in .Net have mostly dried up and all new work is headed towards ROR (and whatever is left towards Java). I have never been apprehensive about learning a new stack/language for fun and have previously picked up Haskell and Python in my free time. I am however apprehensive as to what impact moving to a new entirely different stack would have on my career. What would you do: Change jobs if you don't find anything on .Net soon. Try out the ROR stack for some time. If you find that its not your cup of tea, move back. (How would this impact my career and job opportunities in the longer run?) Also it would be very helpful if there are any ASP.Net MVC folks who have switched over to ROR professionally who can share their experiences. Edit: I have not done any development on a *nix box before. I've however used Ubuntu for fun and games. Sorry if this sounds subjective.

    Read the article

  • List of freely available programming books

    - by Karan Bhangui
    I'm trying to amass a list of programming books with opensource licenses, like Creative Commons, GPL, etc. The books can be about a particular programming language or about computers in general. Hoping you guys could help: Languages BASH Advanced Bash-Scripting Guide (An in-depth exploration of the art of shell scripting) C The C book C++ Thinking in C++ C++ Annotations How to Think Like a Computer Scientist C# .NET Book Zero: What the C or C++ Programmer Needs to Know About C# and the .NET Framework Illustrated C# 2008 (Dead Link) Data Structures and Algorithms with Object-Oriented Design Patterns in C# Threading in C# Common Lisp Practical Common Lisp On Lisp Java Thinking in Java How to Think Like a Computer Scientist Java Thin-Client Programming JavaScript Eloquent JavaScript Haskell Real world Haskell Learn You a Haskell for Great Good! Objective-C The Objective-C Programming Language Perl Extreme Perl (license not specified - home page is saying "freely available") The Mason Book (Open Publication License) Practical mod_perl (CreativeCommons Attribution Share-Alike License) Higher-Order Perl Learning Perl the Hard Way PHP Practical PHP Programming Zend Framework: Survive the Deep End PowerShell Mastering PowerShell Prolog Building Expert Systems in Prolog Adventure in Prolog Prolog Programming A First Course Logic, Programming and Prolog (2ed) Introduction to Prolog for Mathematicians Learn Prolog Now! Natural Language Processing Techniques in Prolog Python Dive Into Python Dive Into Python 3 How to Think Like a Computer Scientist A Byte of Python Python for Fun Invent Your Own Computer Games With Python Ruby Why's (Poignant) Guide to Ruby Programming Ruby - The Pragmatic Programmer's Guide Mr. Neighborly's Humble Little Ruby Book SQL Practical PostgreSQL x86 assembly Paul Carter's tutorial Lua Programming In Lua (for v5 but still largely relevant) Algorithms and Data Structures Algorithms Data Structures and Algorithms with Object-Oriented Design Patterns in Java Planning Algorithms Frameworks/Projects The Django Book The Pylons Book Introduction to Design Patterns in C++ with Qt 4 (Open Publication License) Version control The SVN Book Mercurial: The Definitive Guide Pro Git UNIX / Linux The Art of Unix Programming Linux Device Drivers, Third Edition Others Structure and Interpretation of Computer Programs The Little Book of Semaphores Mathematical Logic - an Introduction An Introduction to the Theory of Computation Developers Developers Developers Developers Linkers and loaders Beej's Guide to Network Programming Maven: The Definitive Guide I will expand on this list as I get comments or when I think of more :D Related: Programming texts and reference material for my Kindle What are some good free programming books? Can anyone recommend a free software engineering book? Edit: Oh I didn't notice the community wiki feature. Feel free to edit your suggestions right in!

    Read the article

< Previous Page | 24 25 26 27 28 29 30 31 32 33 34 35  | Next Page >