Search Results

Search found 16947 results on 678 pages for 'kernel programming'.

Page 95/678 | < Previous Page | 91 92 93 94 95 96 97 98 99 100 101 102  | Next Page >

• Generalist Languages: Dying or Alive and Well?

  - by dsimcha

  Around here, it seems like there's somewhat of a consensus that generalist programming languages (that try to be good at everything, support multiple paradigms, support both very high- and very low-level programming), etc. are a bad idea, and that it's better to pick the right tool for the job and use lots of different languages. I see three major areas where this is flawed: Interfacing multiple languages is always at least a source of friction and is sometimes practically impossible. How severe a problem this is depends on how fine-grained the interfacing is. Near the boundary between the two languages, though, you're basically limited to the intersection of their features, and you have to care about things like binary interfaces that you usually wouldn't. Passing complex data structures (i.e. not just primitives and arrays of primitives) between languages is almost always a hassle. Furthermore, shifting between different syntaxes, different conventions, etc. can be confusing and annoying, though this is a fairly minor complaint. Requirements are never set in stone. I hate picking a language thinking it's the right tool for the job, then realizing that, when some new requirement surfaces, it's actually a terrible choice for that requirement. This has happened to me several times before, usually when working with languages that are very slow, very domain specific and/or has very poor concurrency/parallelism support. When you program in a language for a while, you start to build up a personal toolbox of small utility functions/classes/programs. The value of these goes drastically down if you're forced to use a different language than the one you've accumulated all this code in. What am I missing here? Why shouldn't more focus be placed on generalist languages? Are generalist languages as a category dying or alive and well?

  Read the article

• Benefits of classic OOP over Go-like language

  - by tylerl

  I've been thinking a lot about language design and what elements would be necessary for an "ideal" programming language, and studying Google's Go has led me to question a lot of otherwise common knowledge. Specifically, Go seems to have all of the interesting benefits from object oriented programming without actually having any of the structure of an object oriented language. There are no classes, only structures; there is no class/structure inheritance -- only structure embedding. There aren't any hierarchies, no parent classes, no explicit interface implementations. Instead, type casting rules are based on a loose system similar to duck-typing, such that if a struct implements the necessary elements of a "Reader" or a "Request" or an "Encoding", then you can cast it and use it as one. Does such a system obsolete the concept of OOP? Or is there something about OOP as implemented in C++ and Java and C# that is inherently more capable, more maintainable, somehow more powerful that you have to give up when moving to a language like Go? What benefit do you have to give up to gain the simplicity that this new paradigm represents?

  Read the article

• What can be done against language inertia?

  - by gerrit

  Often, projects use programming language X, but would use programming language Y if they were started from scratch. For example, big numerical models may be written entirely in Fortran. Whereas this might be a reasonable choice for the components that need to run fast (alternative would be C or C++), it might be a poor choice for components that either do not need to run fast (such as things dealing with human input or simple visualisations), or where runtime is not the limiting factor (such as I/O, particularly when from the network). Another example may be when a project is built using a propriety language (such as Matlab; no, FOSS clones are not good enough) and was started at a time when FOSS alternatives were not viable, but ten years later, they are; and it would be beneficial to migrate. However, due to language inertia, a migration does not happen. Code that works should not be touched, porting code is a time-consuming, expensive process, and programmers are familiar in language X but not necessarily in language Y. Still, in the long term, a migration would likely be beneficial. Can anything be done to mitigate the problems associated with language inertia? Are there any notable examples of big projects that have successfully overcome this problem? Or is a project bound to stick forever with the initial choices?

  Read the article

• What's the proper term for a function inverse to a constructor? Deconstructor, destructor, or something else?

  - by Petr Pudlák

  Edit: I'm rephrasing the question a bit. Apparently I caused some confusion because I didn't realize that the term destructor is used in OOP for something quite different - it's a function invoked when an object is being destroyed. In functional programming we (try to) avoid mutable state so there is no such equivalent to it. (I added the proper tag to the question.) Instead, I've seen that the record field for unwrapping a value (especially for single-valued data types such as newtypes) is sometimes called destructor or perhaps deconstructor. For example, let's have (in Haskell): newtype Wrap = Wrap { unwrap :: Int } Here Wrap is the constructor and unwrap is what? I've seen both, for example: ... Most often, one supplies smart constructors and destructors for these to ease working with them. ... at Haskell wiki, or ... The general theme here is to fuse constructor - deconstructor pairs like ... at Haskell wikibook (here it's probably meant in a bit more general sense). The questions are: How do we call unwrap in functional programming? Deconstructor? Destructor? Or by some other term? And to clarify, is this terminology applicable to other functional languages, or is it used just in the Has

  Read the article

• Where to Start?

  - by freemann098

  my name is Chase. I've been programming for over 3 years now and I've made very little progress towards game development. I blame myself for it due to reasons. I have experience in many languages such as C++, C#, and Java. I have a little bit of knowledge in JavaScript/HTML and Python. My question is where to start on actually understanding jumping into game development. Whenever I watch game development tutorials it mostly makes sense until points of things like OpenGL or advanced topics that make no sense at all. An example is something like glOrhho Matrix or whatever. Videos either don't explain things like this or they're not explained very well. Do I not know enough basics? I find myself always copying code from a video but understanding very little of it. It's like i'm memorizing things I don't understand which makes it hard to program at all. If I were to want to get to the point where I could write my own game engine or just a game by myself in general in C++ using at the most documentation how would I start at mastering to that level. Should I learn C first, or get really good at basics in general with C++. I know there is a similar posted question on this site but it's not the same due to the fact the person asking the question has a well knowledge level in programming. I'm stuck in a loop of learning the same things but if I go farther I don't understand. I'm stuck in the same spot and need to make progress.

  Read the article

• Uses of persistent data structures in non-functional languages

  - by Ray Toal

  Languages that are purely functional or near-purely functional benefit from persistent data structures because they are immutable and fit well with the stateless style of functional programming. But from time to time we see libraries of persistent data structures for (state-based, OOP) languages like Java. A claim often heard in favor of persistent data structures is that because they are immutable, they are thread-safe. However, the reason that persistent data structures are thread-safe is that if one thread were to "add" an element to a persistent collection, the operation returns a new collection like the original but with the element added. Other threads therefore see the original collection. The two collections share a lot of internal state, of course -- that's why these persistent structures are efficient. But since different threads see different states of data, it would seem that persistent data structures are not in themselves sufficient to handle scenarios where one thread makes a change that is visible to other threads. For this, it seems we must use devices such as atoms, references, software transactional memory, or even classic locks and synchronization mechanisms. Why then, is the immutability of PDSs touted as something beneficial for "thread safety"? Are there any real examples where PDSs help in synchronization, or solving concurrency problems? Or are PDSs simply a way to provide a stateless interface to an object in support of a functional programming style?

  Read the article

• What's the proper term for a function inverse to a constructor - to unwrap a value from a data type?

  - by Petr Pudlák

  Edit: I'm rephrasing the question a bit. Apparently I caused some confusion because I didn't realize that the term destructor is used in OOP for something quite different - it's a function invoked when an object is being destroyed. In functional programming we (try to) avoid mutable state so there is no such equivalent to it. (I added the proper tag to the question.) Instead, I've seen that the record field for unwrapping a value (especially for single-valued data types such as newtypes) is sometimes called destructor or perhaps deconstructor. For example, let's have (in Haskell): newtype Wrap = Wrap { unwrap :: Int } Here Wrap is the constructor and unwrap is what? The questions are: How do we call unwrap in functional programming? Deconstructor? Destructor? Or by some other term? And to clarify, is this/other terminology applicable to other functional languages, or is it used just in the Haskell? Perhaps also, is there any terminology for this in general, in non-functional languages? I've seen both terms, for example: ... Most often, one supplies smart constructors and destructors for these to ease working with them. ... at Haskell wiki, or ... The general theme here is to fuse constructor - deconstructor pairs like ... at Haskell wikibook (here it's probably meant in a bit more general sense), or newtype DList a = DL { unDL :: [a] -> [a] } The unDL function is our deconstructor, which removes the DL constructor. ... in The Real World Haskell.

  Read the article

• When can you call yourself good at language X?

  - by SoulBeaver

  This goes back to a conversation I've had with my girlfriend. I tried to tell her that I simply don't feel adequate enough in my programming language (C++) to call myself good. She then asked me, "Well, when do you consider yourself good enough?" That's an interesting question. I didn't know what to tell her. So I'm asking you. For any programming language, framework or the like, when do you reach a point were you sit back, look at what you've done and say, "Hey, I'm actually pretty good at this."? How do you define "good" so that you can tell others, honestly, "Yeah, I'm good at X". Additionally, do you reach these conclusions by comparing what others can do? Additional Info I have read the canonical paper on how it takes ten-thousand hours before you are an expert on the field. (Props to anybody that knows what this paper is called again) I have also read various articles from Coding Horror about interviewing people. Some people, it was said, "Cannot function outside of a framework." So they may be "good" for that framework, but not otherwise in the language. Is this true?

  Read the article

• What are some techniques I can use to refactor Object Oriented code into Functional code?

  - by tieTYT

  I've spent about 20-40 hours developing part of a game using JavaScript and HTML5 canvas. When I started I had no idea what I was doing. So it started as a proof of concept and is coming along nicely now, but it has no automated tests. The game is starting to become complex enough that it could benefit from some automated testing, but it seems tough to do because the code depends on mutating global state. I'd like to refactor the whole thing using Underscore.js, a functional programming library for JavaScript. Part of me thinks I should just start from scratch using a Functional Programming style and testing. But, I think refactoring the imperative code into declarative code might be a better learning experience and a safer way to get to my current state of functionality. Problem is, I know what I want my code to look like in the end, but I don't know how to turn my current code into it. I'm hoping some people here could give me some tips a la the Refactoring book and Working Effectively With Legacy Code. For example, as a first step I'm thinking about "banning" global state. Take every function that uses a global variable and pass it in as a parameter instead. Next step may be to "ban" mutation, and to always return a new object. Any advice would be appreciated. I've never taken OO code and refactored it into Functional code before.

  Read the article

• What are some ways to separate game logic from animations and the draw loop?

  - by TMV

  I have only previously made flash games, using MovieClips and such to separate out my animations from my game logic. Now I am getting into trying my hand at making a game for Android, but the game programming theory around separating these things still confuses me. I come from a background of developing non game web applications so I am versed in more MVC like patterns and am stuck in that mindset as I approach game programming. I want to do things like abstract my game by having, for example, a game board class that contains the data for a grid of tiles with instances of a tile class that each contain properties. I can give my draw loop access to this and have it draw the game board based on the properties of each tile on the game board, but I don't understand where exactly animation should go. As far as I can tell, animation sort of sits between the abstracted game logic (model) and the draw loop (view). With my MVC mindset, it's frustrating trying to decide where animation is actually supposed to go. It would have quite a bit of data associated with it like a model, but seemingly needs to be very closely coupled with the draw loop in order to have things like frame independent animation. How can I break out of this mindset and start thinking about patterns that make more sense for games?

  Read the article

• Are specific types still necessary?

  - by MKO

  One thing that occurred to me the other day, are specific types still necessary or a legacy that is holding us back. What I mean is: do we really need short, int, long, bigint etc etc. I understand the reasoning, variables/objects are kept in memory, memory needs to be allocated and therefore we need to know how big a variable can be. But really, shouldn't a modern programming language be able to handle "adaptive types", ie, if something is only ever allocated in the shortint range it uses fewer bytes, and if something is suddenly allocated a very big number the memory is allocated accordinly for that particular instance. Float, real and double's are a bit trickier since the type depends on what precision you need. Strings should however be able to take upp less memory in many instances (in .Net) where mostly ascii is used buth strings always take up double the memory because of unicode encoding. One argument for specific types might be that it's part of the specification, ie for example a variable should not be able to be bigger than a certain value so we set it to shortint. But why not have type constraints instead? It would be much more flexible and powerful to be able to set permissible ranges and values on variables (and properties). I realize the immense problem in revamping the type architecture since it's so tightly integrated with underlying hardware and things like serialization might become tricky indeed. But from a programming perspective it should be great no?

  Read the article

• Spending a good fortune on a certificate holding Scrum Master or a Veteran XP coach?

  - by ashy_32bit

  There is a very prestigious company that delivers a well-sold software about financial systems. It has more that 20 years of history, and is staffed with about 20 programmers and much larger number of managerial staff. Dissatisfied customers have reported strange bugs and no one has a clue what is wrong, hard to read code, and customization is prohibitively expensive. In a word, the software is rotten. The company decided to spend a fortune and found the Agile thing as the remedy but they are stuck about what it is they need most urgently. Is it about the process or the developers or both? The challenge breaks down to the following options: They can hire a certificate holding Scrum Master to teach them Scrum. When asked about the value of doing it, the SM responded: "I will prepare them to embrace Agile and only then they can go Agile and save the product". They can as well hire a veteran XP coach. When posed with the same question he responded : "The most urgent problem is with the programmers and not the management, XP will save the product from rot and only then Scrum will make sense" Developers are far from capable of doing agile programming practices at the moment. No unit tests, no pair programmings, no CI (huh? what is it?) ... you get the idea. Some say they would be far better trying to improve their programming first (hire option 2) and then go with the process. Many say quite the opposite. Any insights ?

  Read the article

• Laser range finder, what language to use? Beginner advice

  - by DrOnline

  I hope this is the right place. I am a programming beginner, and I want to make a laser range finder, and I need advice about how to proceed etc. In a few weeks I will get a lot of dirt cheap 3-5V lasers and some cheap usb webcams. I will point the laser and webcam in parallel, and somehow use trigonometry and programming to determined distance. I have seen online that others made done it this way, I have purposefully not looked at the details too much because I want to develop it on my own, and learn, but I know the general outline. I have a general idea of how to proceed. The program loads in a picture from the webcam, and I dunno how images work really, but I imagine there is a format that is basically an array of RGB values.. is this right? I will load in the red values, and find the most red one. I know the height difference between the laser and the cam. I know the center dot in the image, I know the redmost dot. I'm sure there's some way to figure out some range there. TO THE POINT: 1) Is my reasoning sound thus far, especially in terms of image analysis? I don't need complete solutions, just general points 2) What I need to figure out, is what platform to use. I have an arduino... apparently, I've read it's too weak to process images. Read that online. I know some C I know some Python I have Matlab. Which is the best option? I do not need high sampling rates, I have not decided on whether it should be automated or whether I should make a GUI with a button to press for samples. I will keep it simple and expand I think. I also do not need it to be super accurate, I'm just having fun here. Advice!

  Read the article

• Order of the [BITS 16] and [ORG 0x0000] directives

  - by dboarman-FissureStudios

  I am beginning some experimentation in writing a kernel and having fun doing it. I have the basic boot-loader done and the following directives: [BITS 16] [ORG 0x0000] In the kernel tutorial, however, it starts with: [ORG 0x0000] [BITS 16] I was wondering if the order in which these directives are given makes a difference? I am using NASM version 2.06rc2, OpenSUSE 11.2

  Read the article

• Reliability of UDP on localhost

  - by Bryan Ward

  I know that UDP is inherently unreliable, but when connecting to localhost I would expect the kernel handles the connection differently since everything can be handled internally. So in this special case, is UDP considered a reliable protocol, or will the kernel still potentially junk some packets if buffers are overrun?

  Read the article

• Do the changes to cpumask using sched_setaffinity() take place immediately

  - by Sukanto

  I am writing a linux kernel module that needs to pin two threads on two different cpus. I am planning to use sched_setaffinity() after exporting it in the kernel. Is there any other exported function for the same ? Also, if I set only 1 CPU in the cpumask, will the thread be moved to that cpu with immediate effect ? If not, how do I enforce the same ? Will it help to call schedule() just after sched_setaffinity() ?

  Read the article

• Turn off the Linux OOM killer by default?

  - by Peter Eisentraut

  The OOM killer on Linux wreaks havoc with various applications every so often, and it appears that not much is really done on the kernel development side to improve this. Would it not be better, as a best practice when setting up a new server, to reverse the default on the memory overcommitting, that is, turn it off (vm.overcommit_memory=2) unless you know you want it on for your particular use? And what would those use cases be where you know you want the overcommitting on? As a bonus, since the behavior in case of vm.overcommit_memory=2 depends on vm.overcommit_ratio and swap space, what would be a good rule of thumb for sizing the latter two so that this whole setup keeps working reasonably?

  Read the article

• Linux halts every few seconds

  - by Zeppomedio

  We're having an issue where one our Linux boxes (Ubuntu 10.04 LTS, running on EC2 with a quadruple-large size, 68GB of RAM and 8 virtual cores with 3.25GHz each) freezes up every few seconds. Typing in an ssh session will freeze, and running strace on one of the Postgresql processes that's running usually shows: 02:37:41.567990 semop(7831581, {{3, -1, 0}}, 1 for a few seconds before it proceeds (it always gets stuck at that semop). OProfile shows that most of the time is spent in the kernel (60%) versus 37% in Postgresql. The result of these halts (which began suddenly a day ago) is that load on the box has gone from 0.7 to 10+, and causes our entire stack to slow done. Any ideas on how to track down what's going on? iostat doesn't show the disks being particularly slow or overloaded, and top shows user cpu % spike from 8% to about 40% whenever these back-ups happen.

  Read the article

• taskmgr.exe 100% CPU Usage

  - by Burnsys

  Hi. I have 2 IBM servers Intel Xeon Dual core with 2gb RAM. the problem is that Taskmanager uses one full core when i open it. The same happens when i copy files in the explorer. OS: Windows 2003 Server Things i tried: Installed all updates They has kaspersky anti virus and they previously had Nod32. All drivers installed OK. All unused devices are disabled in the bios. Reinstalled win 2003 SP2. No conflict in drivers Tried opening via remote desktop and the problem continues. The cpu utilization is in the Kernel Times (Red in taskmanager) If i open Proces Explorer and i navigate to the threads consuming CPU the stack traces ends always in "NtkrnlPA!UnexpectedInterrupt", all threads stacks end in "UnexpectedInterrupt" ntoskrnl.exe!KiUnexpectedInterrupt+0x48 ntoskrnl.exe!KeWaitForMutexObject+0x20e ntoskrnl.exe!CcSetReadAheadGranularity+0x1ff9 ntoskrnl.exe!IoAllocateIrp+0x3fd ntoskrnl.exe!KeWaitForMutexObject+0x20e ntoskrnl.exe!NtWaitForSingleObject+0x94 ntoskrnl.exe!DbgBreakPointWithStatus+0xe05 ntdll.dll!KiFastSystemCallRet kernel32.dll!WaitForSingleObject+0x12 taskmgr.exe+0xeef6 kernel32.dll!GetModuleHandleA+0xdf Any help would be appreciated!

  Read the article

• unable to install new versions of linux on my PC

  - by iamrohitbanga

  I have an MSI-RC410 motherboard with onboard ATI Radeon XPress 200 series Graphics card. I have used OpenSuse-11.0 on my PC for over an year. but when I tried to upgrade to OpenSuse-11.1, I managed to install it only to find that several features were missing. for example /dev/cdrom was missing. Also install DVD of Fedora 11 did not work. I have also tried Ubuntu-9.10 live cd. When I boot from the CD i get the initramfs command prompt. Still able to install old versions of these OSs. What is the reason for this behavior? Does it have to do anything with the new version of the linux kernel not being compatible with my hardware? What should i do to install new versions of Linux?

  Read the article

• About rw init=/bin/bash

  - by triedtoomuck

  I am a linux newbie so excuse me if I ask silly things. I recently find out that if I edit GRUB before booting and I add rw init=/bin/bash I end up with a root shell. Being in a condition that I want to understand everything I would like to know why this happens. I mean is it a bug? is it a feature? is it there to help admins to fix things as it only works if you have physical access to a computer? Which part are we exploiting? GRUB or the actual kernel? Sorry for asking a lot of things.

  Read the article

• unable to install new versions of linux on my PC

  - by iamrohitbanga

  I have an MSI-RC410 motherboard with onboard ATI Radeon XPress 200 series Graphics card. I have used OpenSuse-11.0 on my PC for over an year. but when I tried to upgrade to OpenSuse-11.1, I managed to install it only to find that several features were missing. for example /dev/cdrom was missing. Also install DVD of Fedora 11 did not work. I have also tried Ubuntu-9.10 live cd. When I boot from the CD i get the initramfs command prompt. Still able to install old versions of these OSs. What is the reason for this behavior? Does it have to do anything with the new version of the linux kernel not being compatible with my hardware? What should i do to install new versions of Linux?

  Read the article

• Munin "Available entropy" when using address space layout randomization

  - by clawspoon

  Having just configured Munin for statistics logging on my gentoo server (hardened profile), I am noticing that my "Available entropy" is consitently in the 200-300 range. This seems way to low, so I checked it manually using the command $ cat /proc/sys/kernel/random/entropy_avail 3544 Odd. Consistently very low values in Munin and practically filled up when checking manually. After thinking about the problem for a while I came to the conclusion that the problem is probably that I'm using Adress Space Layout Randomization which is using the entropy when running commands/programs. Since Munin runs a whole slew of programs all the entropy is used up, and Munin then measures how much entropy there is, resulting in the low values. Does anyone have any experience with this? How can this be avoided?

  Read the article

• Linux PCIE Physical Bus Address

  - by Without me Its just Aweso

  I am working on designing a custom PCIexpress card. I am trying to write a kernel module that will DMA my custom card. Right now when i plug the card into linux no valid PCI device shows up (meaning I probably have a error on my end, i know) however, If I halt the system at startup in the bootloader (uboot) I am able to directly access the card as I know in uboot the physical memory address that is mapped to my device. Is there a way I can access the card in a simliar fashion in linux? Thanks, Stephanie

  Read the article

• How to add/remove codecs in linux

  - by agg

  Friends, I'm new to Linux, I need to work on Linux. I have ported Linux to AT91SAM9261-EK board. Now i need to work on Codecs. I just know the definition of codec from wikipedia, Now i need add my own codec to the board. I want to know, Where codec will be preset in 1)File System, 2)Kernel or 3)Player And how to add codec while building entire source, please tell me the steps i need follow. And also how to remove the codec. How to play the video files from pendrive in console, now i can play audio by command 'mplayer "filename" '. Don't know how to play video. Please help me, How to do this. Regards AGG

  Read the article

< Previous Page | 91 92 93 94 95 96 97 98 99 100 101 102  | Next Page >