Search Results

Search found 15377 results on 616 pages for 'socket programming'.

Page 536/616 | < Previous Page | 532 533 534 535 536 537 538 539 540 541 542 543  | Next Page >

• How quickly to leave contract-to-hire gig where you don't want to be hired? [closed]

  - by nono

  So you move to a big new city with tons of software development opportunity, having taken a six month contract-to-hire job. The company treats you really well and has a good team and work environment. However, the recruiter assured you when offering the gig that it would be a good position in which you can advance your learning from more senior developers (a primary concern of yours) but you're starting to realize that a job recruiter isn't going to understand that the team in question isn't very up on modern software practices (you start to sympathize with this guy and read his post over and over again: http://stackoverflow.com/questions/1586166/career-killer-nhibernate-oop-design-patterns-domain-driven-design-test-driv) and that much of the company's software is very old and very very poorly architected, and the company (like so many others) seems to be only concerned with continually extending the software without investing in any structural improvements. You're absolutely dismayed at how long it takes your team (including) to fulfill simple feature requests (maybe 500-1000% longer than with better designed software that you've worked on in the past), but no one else there seems to think anything of it. You find that the work and the company's business are intensely uninteresting to you, but due to the convoluted design of their various software systems, fulfilling the work will require as much mental engagement as any other development position. You feel a bit naive about not having asked the right questions during your interview process, and for not having anticipated that your team at your former podunk company might possibly be light-years ahead of any team in Big Shiny City, but you know you don't want to stay at this place, and (were it not for your personal, after-hours studying and personal programming efforts) fear that you might actually give a worse interview after completing your 6 months than you did when you started at the place. You read about how hard of a time local companies are having filling their positions with qualified software development candidates. You read all sorts of fabulous sounding job postings online and feel like you're really missing out. In spite of the comfortable environment you feel like you would willingly accept a somewhat more demanding or aggressive lifestyle to feel like you are learning and progressing and producing something meaningful. My questions are: how quickly do you leave and how do you go about giving a polite reason for departing? The contract is written to allow them to "can" you and to allow you to leave with 2 weeks notice. Do you ethically owe the 6 months? Upon taking the position, the company told you they were not interested in candidates who were intending to only stay for 6 months and then leave (you were not intending to bail after 6 months, at that time), so perhaps they might be fine if you split now, knowing that you don't want to stick around for the full time hire?

  Read the article

• What is the recommended way to output values to FBO targets? (OpenGL 3.3 + GLSL 330)

  - by datSilencer

  I'll begin by apologizing for any dumb assumptions you might find in the code below since I'm still pretty much green when it comes to OpenGL programming. I'm currently trying to implement deferred shading by using FBO's and their associated targets (textures in my case). I have a simple (I think :P) geometry+fragment shader program and I'd like to write its Fragment Shader stage output to three different render targets (previously bound by a call to glDrawBuffers()), like so: #version 330 in vec3 WorldPos0; in vec2 TexCoord0; in vec3 Normal0; in vec3 Tangent0; layout(location = 0) out vec3 WorldPos; layout(location = 1) out vec3 Diffuse; layout(location = 2) out vec3 Normal; uniform sampler2D gColorMap; uniform sampler2D gNormalMap; vec3 CalcBumpedNormal() { vec3 Normal = normalize(Normal0); vec3 Tangent = normalize(Tangent0); Tangent = normalize(Tangent - dot(Tangent, Normal) * Normal); vec3 Bitangent = cross(Tangent, Normal); vec3 BumpMapNormal = texture(gNormalMap, TexCoord0).xyz; BumpMapNormal = 2 * BumpMapNormal - vec3(1.0, 1.0, -1.0); vec3 NewNormal; mat3 TBN = mat3(Tangent, Bitangent, Normal); NewNormal = TBN * BumpMapNormal; NewNormal = normalize(NewNormal); return NewNormal; } void main() { WorldPos = WorldPos0; Diffuse = texture(gColorMap, TexCoord0).xyz; Normal = CalcBumpedNormal(); } If my render target textures are configured as: RT1:(GL_RGB32F, GL_RGB, GL_FLOAT, GL_TEXTURE0, GL_COLOR_ATTACHMENT0) RT2:(GL_RGB32F, GL_RGB, GL_FLOAT, GL_TEXTURE1, GL_COLOR_ATTACHMENT1) RT3:(GL_RGB32F, GL_RGB, GL_FLOAT, GL_TEXTURE2, GL_COLOR_ATTACHMENT2) And assuming that each texture has an internal format capable of contaning the incoming data, will the fragment shader write the corresponding values to the expected texture targets? On a related note, do the textures need to be bound to the OpenGL context when they are Multiple Render Targets? From some Googling, I think there are two other ways to output to MRTs: 1: Output each component to gl_FragData[n]. Some forum posts say this method is deprecated. However, looking at the latest OpenGL 3.3 and 4.0 specifications at opengl.org, the core profiles still mention this approach. 2: Use a typed output array variable for the expected type. In this case, I think it would be something like this: out vec3 [3] output; void main() { output[0] = WorldPos0; output[1] = texture(gColorMap, TexCoord0).xyz; output[2] = CalcBumpedNormal(); } So which is then the recommended approach? Is there a recommended approach at all if I plan to code on top of OpenGL 3.3? Thanks for your time and help!

  Read the article

• StringBuffer behavior in LWJGL

  - by Michael Oberlin

  Okay, I've been programming in Java for about ten years, but am entirely new to LWJGL. I have a specific problem whilst attempting to create a text console. I have built a class meant to abstract input polling to it, which (in theory) captures key presses from the Keyboard object and appends them to a StringBuilder/StringBuffer, then retrieves the completed string after receiving the ENTER key. The problem is, after I trigger the String return (currently with ESCAPE), and attempt to print it to System.out, I consistently get a blank line. I can get an appropriate string length, and I can even sample a single character out of it and get complete accuracy, but it never prints the actual string. I could swear that LWJGL slipped some kind of thread-safety trick in while I wasn't looking. Here's my code: static volatile StringBuffer command = new StringBuffer(); @Override public void chain(InputPoller poller) { this.chain = poller; } @Override public synchronized void poll() { //basic testing for modifier keys, to be used later on boolean shift = false, alt = false, control = false, superkey = false; if(Keyboard.isKeyDown(Keyboard.KEY_LSHIFT) || Keyboard.isKeyDown(Keyboard.KEY_RSHIFT)) shift = true; if(Keyboard.isKeyDown(Keyboard.KEY_LMENU) || Keyboard.isKeyDown(Keyboard.KEY_RMENU)) alt = true; if(Keyboard.isKeyDown(Keyboard.KEY_LCONTROL) || Keyboard.isKeyDown(Keyboard.KEY_RCONTROL)) control = true; if(Keyboard.isKeyDown(Keyboard.KEY_LMETA) || Keyboard.isKeyDown(Keyboard.KEY_RMETA)) superkey = true; while(Keyboard.next()) if(Keyboard.getEventKeyState()) { command.append(Keyboard.getEventCharacter()); } if (Framework.isConsoleEnabled() && Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) { System.out.println("Escape down"); System.out.println(command.length() + " characters polled"); //works System.out.println(command.toString().length()); //works System.out.println(command.toString().charAt(4)); //works System.out.println(command.toString().toCharArray()); //blank line! System.out.println(command.toString()); //blank line! Framework.disableConsole(); } //TODO: Add command construction and console management after that } } Maybe the answer's obvious and I'm just feeling tired, but I need to walk away from this for a while. If anyone sees the issue, please let me know. This machine is running the latest release of Java 7 on Ubuntu 12.04, Mate desktop environment. Many thanks.

  Read the article

• Understanding the levels of computing

  - by RParadox

  Sorry, for my confused question. I'm looking for some pointers. Up to now I have been working mostly with Java and Python on the application layer and I have only a vague understanding of operating systems and hardware. I want to understand much more about the lower levels of computing, but it gets really overwhelming somehow. At university I took a class about microprogramming, i.e. how processors get hard-wired to implement the ASM codes. Up to now I always thought I wouldn't get more done if learned more about the "low level". One question I have is: how is it even possible that hardware gets hidden almost completely from the developer? Is it accurate to say that the operating system is a software layer for the hardware? One small example: in programming I have never come across the need to understand what L2 or L3 Cache is. For the typical business application environment one almost never needs to understand assembler and the lower levels of computing, because nowadays there is a technology stack for almost anything. I guess the whole point of these lower levels is to provide an interface to higher levels. On the other hand I wonder how much influence the lower levels can have, for example this whole graphics computing thing. So, on the other hand, there is this theoretical computer science branch, which works on abstract computing models. However, I also rarely encountered situations, where I found it helpful thinking in the categories of complexity models, proof verification, etc. I sort of know, that there is a complexity class called NP, and that they are kind of impossible to solve for a big number of N. What I'm missing is a reference for a framework to think about these things. It seems to me, that there all kinds of different camps, who rarely interact. The last few weeks I have been reading about security issues. Here somehow, much of the different layers come together. Attacks and exploits almost always occur on the lower level, so in this case it is necessary to learn about the details of the OSI layers, the inner workings of an OS, etc.

  Read the article

• Best practice for organizing/storing character/monster data in an RPG?

  - by eclecto

  Synopsis: Attempting to build a cross-platform RPG app in Adobe Flash Builder and am trying to figure out the best class hierarchy and the best way to store the static data used to build each of the individual "hero" and "monster" types. My programming experience, particularly in AS3, is embarrassingly small. My ultra-alpha method is to include a "_class" object in the constructor for each instance. The _class, in turn, is a static Object pulled from a class created specifically for that purpose, so things look something like this: // Character.as package { public class Character extends Sprite { public var _strength:int; // etc. public function Character(_class:Object) { _strength = _class._strength; // etc. } } } // MonsterClasses.as package { public final class MonsterClasses extends Object { public static const Monster1:Object={ _strength:50, // etc. } // etc. } } // Some other class in which characters/monsters are created. // Create a new instance of Character var myMonster = new Character(MonsterClasses.Monster1); Another option I've toyed with is the idea of making each character class/monster type its own subclass of Character, but I'm not sure if it would be efficient or even make sense considering that these classes would only be used to store variables and would add no new methods. On the other hand, it would make creating instances as simple as var myMonster = new Monster1; and potentially cut down on the overhead of having to read a class containing the data for, at a conservative preliminary estimate, over 150 monsters just to fish out the one monster I want (assuming, and I really have no idea, that such a thing might cause any kind of slowdown in execution). But long story short, I want a system that's both efficient at compile time and easy to work with during coding. Should I stick with what I've got or try a different method? As a subquestion, I'm also assuming here that the best way to store data that will be bundled with the final game and not read externally is simply to declare everything in AS3. Seems to me that if I used, say, XML or JSON I'd have to use the associated AS3 classes and methods to pull in the data, parse it, and convert it to AS3 object(s) anyway, so it would be inefficient. Right?

  Read the article

• How is a switch statement better than a series of if statements? [closed]

  - by user1276078

  Possible Duplicate: Should I use switch statements or long if…else chains? I'm working on a small program that will conduct an Insertion Sort. A number will be inputted through the keyboard and stored in a variable I called "num." I've decided to use a switch statement in order to obtain the number inputted. switch( e.getKeyCode() ) { case KeyEvent.VK_0: num = 0; break; case KeyEvent.VK_1: num = 1; break; case KeyEvent.VK_2: num = 2; break; case KeyEvent.VK_3: num = 3; break; case KeyEvent.VK_4: num = 4; break; case KeyEvent.VK_5: num = 5; break; case KeyEvent.VK_6: num = 6; break; case KeyEvent.VK_7: num = 7; break; case KeyEvent.VK_8: num = 8; break; case KeyEvent.VK_9: num = 9; break; } I realized one other course of action could have been to use a set of if statements. if( e.getKeyCode() == KeyEvent.VK_0 ) num = 0; else if( e.getKeyCode() == KeyEvent.VK_1 ) num = 1; etc. for every number up until 9. I then wondered what the essential difference is between a switch statement and a series of if statements. I know it saves space and time to write, but it's not that much. So, my question is, aside from the space, does a switch statement differ from a series of if statments in any way? Is it faster, less error-prone, etc.? This question really doesn't affect my code that much. I was just wondering. Also, this question pertains to the JAVA language, not any other programming language.

  Read the article

• What OpenGL version(s) to learn and/or use?

  - by zuko

  So, I'm new to OpenGL... I have general knowledge of game programming but little practical experience. I've been looking into various articles and books and trying to dive into OpenGL, but I've found the various versions and old vs new way of doing things confusing. I guess my first questions is does anyone know some figures about percentages of gamers that can run each version of OpenGL. What's the market share like? 2.x, 3.x, 4.x... I looked into the requirements for Half Life 2 since I know Valve updated it with OpenGL to run on Mac and I know they usually try to hit a very wide user-base, and they say a minimum of GeForce 8 Series. I looked at the 8800 GT on Nvidia's website and it listed support for OpenGL 2.1. Which, maybe I'm wrong, sounds ancient to me since there's already 4.x. I looked up a driver for 8800GT and it says it supports 4.2! A bit of a discrepancy there, lol. I've also read things like XP only supports up to a certain version, or OS X only supports 3.2, or all kinds of other things. Overall, I'm just confused as to how much support there is for various versions and what version to learn/use. I'm also looking for learning resources. My search results thus far have pointed me to the OpenGL SuperBible. The 4th edition has great reviews on Amazon, but it teaches 2.1. The 5th edition teaches 3.3 and there are a couple things in the reviews that mention the 4th edition is better and that the 5th edition doesn't properly teach the new features or something? Basically, even within learning material I'm seeing discrepancies and I just don't even know where to start. From what I understand, 3.x started a whole new way of doing things and I've read from various articles and reviews that you want to "stay away from deprecated features like glBegin(), glEnd()" yet a lot of books and tutorials I've seen use that method. I've seen people saying that, basically, the new way of doing stuff is more complicated yet the old way is bad . Just a side note, personally, I know I still have a lot to learn beforehand, but I'm interested in tessellation; so I guess that factors into it as well, because, as far as I understand that's only in 4.x? [just btw, my desktop supports 4.2]

  Read the article

• Applying the Knuth-Plass algorithm (or something better?) to read two books with different length and amount of chapters in parallel

  - by user147133

  I have a Bible reading plan that covers the whole Bible in 180 days. For the most of the time, I read 5 chapters in the Old Testament and 1 or 2 (1.5) chapters in the New Testament each day. The problem is that some chapters are longer than others (for example Psalm 119 which is 7 times longer than a average chapter in the Bible), and the plan I'm following doesn't take that in count. I end up with some days having a lot more to read than others. I thought I could use programming to make myself a better plan. I have a datastructure with a list of all chapters in the bible and their length in number of lines. (I found that the number of lines is the best criteria, but it could have been number of verses or number of words as well) I then started to think about this problem as a line wrap problem. Think of a chapter like a word, a day like a line and the whole plan as a paragraph. The "length" of a word (a chapter) is the number of lines in that chapter. I could then generate the best possible reading plan by applying a simplified Knuth-Plass algorithm to find the best breakpoints. This works well if I want to read the Bible from beginning to end. But I want to read a little from the new testament each day in parallel with the old testament. Of course I can run the Knuth-Plass algorithm on the Old Testament first, then on the New Testament and get two separate plans. But those plans merged is not a optimal plan. Worst-case days (days with extra much reading) in the New Testament plan will randomly occur on the same days as the worst-case days in the Old Testament. Since the New Testament have about 180*1.5 chapters, the plan is generally to read one chapter the first day, two the second, one the third etc... And I would like the plan for the Old Testament to compensate for this alternating length. So I will need a new and better algorithm, or I will have to use the Knuth-Plass algorithm in a way that I've not figured out. I think this could be a interesting and challenging nut for people interested in algorithms, so therefore I wanted to see if any of you have a good solution in mind.

  Read the article

• I'm graduating with a Computer Science degree but I don't feel like I know how to program.

  - by wp123

  I'm graduating with a Computer Science degree but I see websites like Stack Overflow and search engines like Google and don't know where I'd even begin to write something like that. During one summer I did have the opportunity to work as a iPhone developer, but I felt like I was mostly gluing together libraries that other people had written with little understanding of the mechanics happening beneath the hood. I'm trying to improve my knowledge by studying algorithms, but it is a long and painful process. I find algorithms difficult and at the rate I am learning a decade will have passed before I will master the material in the book. Given my current situation, I've spent a month looking for work but my skills (C, Python, Objective-C) are relatively shallow and are not so desirable in the local market, where C#, Java, and web development are much higher in demand. That is not to say that C and Python opportunities do not exist but they tend to demand 3+ years of experience I do not have. My GPA is OK (3.0) but it's not high enough to apply to the large companies like IBM or return for graduate studies. Basically I'm graduating with a Computer Science degree but I don't feel like I've learned how to program. I thought that joining a company and programming full-time would give me a chance to develop my skills and learn from those more experienced than myself, but I'm struggling to find work and am starting to get really frustrated. I am going to cast my net wider and look beyond the city I've grown up in, but what have other people in similar situation tried to do? I've worked hard but don't have the confidence to go out on my own and write my own app. (That is, become an indie developer in the iPhone app market.) If nothing turns up I will need to consider upgrading and learning more popular skills or try something marginally related like IT, but given all the effort I've put in that feels like copping out. EDIT: Thank you for all the advice. I think I was premature because of unrealistic expectations but the comments have given me a dose of reality. I will persevere and continue to code. I have a project in mind, although well beyond my current capabilities it will challenge me to hone my craft and prove my worth to myself (and potential employers). Had I known there was a career overflow I would have posted there instead. Thanks again!

  Read the article

• How to do proper Alpha in XNA?

  - by Soshimo

  Okay, I've read several articles, tutorials, and questions regarding this. Most point to the same technique which doesn't solve my problem. I need the ability to create semi-transparent sprites (texture2D's really) and have them overlay another sprite. I can achieve that somewhat with the code samples I've found but I'm not satisfied with the results and I know there is a way to do this. In mobile programming (BREW) we did it old school and actually checked each pixel for transparency before rendering. In this case it seems to render the sprite below it blended with the alpha above it. This may be an artifact of how I'm rendering the texture but, as I said before, all examples point to this one technique. Before I go any further I'll go ahead and paste my example code. public void Draw(SpriteBatch batch, Camera camera, float alpha) { int tileMapWidth = Width; int tileMapHeight = Height; batch.Begin(SpriteSortMode.Texture, BlendState.AlphaBlend, SamplerState.PointWrap, DepthStencilState.Default, RasterizerState.CullNone, null, camera.TransformMatrix); for (int x = 0; x < tileMapWidth; x++) { for (int y = 0; y < tileMapHeight; y++) { int tileIndex = _map[y, x]; if (tileIndex != -1) { Texture2D texture = _tileTextures[tileIndex]; batch.Draw( texture, new Rectangle( (x * Engine.TileWidth), (y * Engine.TileHeight), Engine.TileWidth, Engine.TileHeight), new Color(new Vector4(1f, 1f, 1f, alpha ))); } } } batch.End(); } As you can see, in this code I'm using the overloaded SpriteBatch.Begin method which takes, among other things, a blend state. I'm almost positive that's my problem. I don't want to BLEND the sprites, I want them to be transparent when alpha is 0. In this example I can set alpha to 0 but it still renders both tiles, with the lower z ordered sprite showing through, discolored because of the blending. This is not a desired effect, I want the higher z-ordered sprite to fade out and not effect the color beneath it in such a manner. I might be way off here as I'm fairly new to XNA development so feel free to steer me in the correct direction in the event I'm going down the wrong rabbit hole. TIA

  Read the article

• reference list for non-IT driven algorithmic patterns

  - by Quicker

  I am looking for a reference list for non-IT driven algorithmic patterns (which still can be helped with IT implementations of IT). An Example List would be: name; short desc; reference Travelling Salesman; find the shortest possible route on a multiple target path; http://en.wikipedia.org/wiki/Travelling_salesman_problem Ressource Disposition (aka Regulation); Distribute a limited/exceeding input on a given number output receivers based on distribution rules; http://database-programmer.blogspot.de/2010/12/critical-analysis-of-algorithm-sproc.html If there is no such list, but you instantly think of something specific, please 'put it on the desk'. Maybe I can compile something out of the input I get here (actually I am very frustrated as I did not find any such list via research by myself). Details on Scoping: I found it very hard to formulate what I want in a way everything is out that I do not need (which may be the issue why I did not find anything at google). There is a database centric definition for what I am looking for in the section 'Processes' of the second example link. That somehow fits, but the database focus sort of drifts away from the pattern thinking, which I have in mind. So here are my own thoughts around what's in and what's out: I am NOT looking for a foundational algo ref list, which is implemented as basis for any programming language. Eg. the php reference describes substr and strlen. That implements algos, but is not what I am looking for. the problem the algo does address would even exist, if there were no computers (or other IT components) the main focus of the algo is NOT to help other algo's chances are high, that there are implementions of the solution or any workaround without any IT support out there in the world however the algo could be benefitialy implemented/fully supported by a software application = means: the problem of the algo has to be addressed anyway, but running an algo implementation with software automates the process (that is why I posted it on stackoverflow and not somewhere else) typically such algo implementations have more than one input field value and more than one output field value - which implies it could not be implemented as simple function (which is fixed to produce not more than one output value) in a normalized data model often times such algo implementation outputs span accross multiple rows (sometimes multiple tables), whereby the number of output rows depends on the input paraters and rows in the table(s) at start time - which implies that any algo implementation/procedure must interact with a database (read and/or write) I am mainly looking for patterns, not for specific implementations. Example: The Travelling Salesman assumes any coordinates, however it does not say: You need a table targets with fields x and y. - however sometimes descriptions are focussed on examples with specific implementations very much - no worries, as long as the pattern gets clear

  Read the article

• Developer career feeling like going back in time every new job [closed]

  - by komediant

  Is there a good category for this question? My background is bachelor in ICT and for a hobby I am programming already since I was around twelve I think. Started with QBasic, Pascal, C, Java et cetera. Currently I am working for about eight/nine years. Half academics/medical and half company world. A few years ago I started with frameworks and I began with Grails (underlying Spring/Hibernate), which was a heavenly job, very productive and no hassle. My previous job I developed in pure Spring/Hibernate Java, which was a bit more writing annotations and XML and no conventions like Grails. But still, I did like Spring/Hibernate a lot and the professional setup with a developmentstreet, versioning, Jenkins/Sonar, log4j and a good IDE like IntellIJ. It felt quite 'clear' and organised, although I knew Grails which felt a bit more productive. But...at my current job almost half the code is pure servlet, hard coded JDBC (connections handled by yourself), scriptlets in all JSP pages, no service layer, no versioning, no Maven, HTML in DAO-layer, JAR-hell, no hot swap deployment locally, every change you have to deploy and hope it works fine on the server. All local development needs ugly scriptlet tags to check which environment it is running. Et cetera. Now and then developers work over in the evening - I don't - and still lots of issues are not solved and new projects are waiting. I hear the developers complaining, but somehow they feel like what they have now is "advanced" or they are in a sort of comfore zone. The lead developer seems open for new things, but half of the times he says he can implement MVC-framework features himself instead of using what is already out there. So in short, I currently feel like I miss all the modern framework techniques and that the company is going so slow forward. I just work here for two months now. What I do now is also code some partially ugly stuff, but it goes in completely into my nature and I feel uncomfortable with it. Coding something takes long(er) than estimated and my manager complains about why it takes so long and I feel ashamed for myself needing so much time. Where I was used to just writing a query I now build up whole try catch methods. My manager knows my complaints and the developers do so too. There will come a meeting to line out plans for 2013 on technology and the issues I and the company are facing. I am not looking for another job yet, it's close to wehre I live and the economy is fragile. Does anyone else have had this kind of career, like feeling going backwards witch technology? And how did you cope with it?

  Read the article

• Does OO, TDD, and Refactoring to Smaller Functions affect Speed of Code?

  - by Dennis

  In Computer Science field, I have noticed a notable shift in thinking when it comes to programming. The advice as it stands now is write smaller, more testable code refactor existing code into smaller and smaller chunks of code until most of your methods/functions are just a few lines long write functions that only do one thing (which makes them smaller again) This is a change compared to the "old" or "bad" code practices where you have methods spanning 2500 lines, and big classes doing everything. My question is this: when it call comes down to machine code, to 1s and 0s, to assembly instructions, should I be at all concerned that my class-separated code with variety of small-to-tiny functions generates too much extra overhead? While I am not exactly familiar with how OO code and function calls are handled in ASM in the end, I do have some idea. I assume that each extra function call, object call, or include call (in some languages), generate an extra set of instructions, thereby increasing code's volume and adding various overhead, without adding actual "useful" code. I also imagine that good optimizations can be done to ASM before it is actually ran on the hardware, but that optimization can only do so much too. Hence, my question -- how much overhead (in space and speed) does well-separated code (split up across hundreds of files, classes, and methods) actually introduce compared to having "one big method that contains everything", due to this overhead? UPDATE for clarity: I am assuming that adding more and more functions and more and more objects and classes in a code will result in more and more parameter passing between smaller code pieces. It was said somewhere (quote TBD) that up to 70% of all code is made up of ASM's MOV instruction - loading CPU registers with proper variables, not the actual computation being done. In my case, you load up CPU's time with PUSH/POP instructions to provide linkage and parameter passing between various pieces of code. The smaller you make your pieces of code, the more overhead "linkage" is required. I am concerned that this linkage adds to software bloat and slow-down and I am wondering if I should be concerned about this, and how much, if any at all, because current and future generations of programmers who are building software for the next century, will have to live with and consume software built using these practices. UPDATE: Multiple files I am writing new code now that is slowly replacing old code. In particular I've noted that one of the old classes was a ~3000 line file (as mentioned earlier). Now it is becoming a set of 15-20 files located across various directories, including test files and not including PHP framework I am using to bind some things together. More files are coming as well. When it comes to disk I/O, loading multiple files is slower than loading one large file. Of course not all files are loaded, they are loaded as needed, and disk caching and memory caching options exist, and yet still I believe that loading multiple files takes more processing than loading a single file into memory. I am adding that to my concern.

  Read the article

• Building a Store Locator ASP.NET Application Using Google Maps API

  The past couple of projects I've been working on have included the use of the Google Maps API and geocoding service in websites for various reasons. I decided to tie together some of the lessons learned, build an ASP.NETstore locator demo, and write about it on 4Guys. Last week I published the first article in what I think will be a three-part series: Building a Store Locator ASP.NET Application Using Google Maps (Part 1). Part 1 walks through creating a demo where a user can type in an address and any stores within a (roughly) 15 mile area will be displayed in a grid.The article begins with a look at the database used to power the store locator (namely, a single table that contains one row for every location, with each location storing its store number, address, and, most important, latitude and longitude coordinates) and then turns to usingGoogle's geocoding service to translatea user-entered address into latitude and longitude coordinates. The latitude and longitude coordinates are used to find nearby stores, which are then displayed in a grid. Part 2 looks at enhancing the search results to include a map with markers indicating the position of each nearby store location. The Google Maps API, along with a bit of client-side script and server-side logic, make this actually pretty straightforward and easy to implement. Here's a screen shot of the improved store locator results. Part 3, which I plan on publishing next week, looks at how to enhance the map by using information windows to display address information when clicking a marker. Additionally, I'll show how to use custom icons for the markers so that instead of having the same marker for each nearby location the markers will be images numbered 1, 2, 3, and so on, which will correspond to a number assigned to each search result in the grid. The idea here is that by numbering the search results in the grid and the markers on the map visitors will quickly be able to see what marker corresponds to what search result. This article and demo has been a lot of fun to write and create, and I hope you enjoy reading it, too. Building a Store Locator ASP.NET Application Using Google Maps API (Part 1) Building a Store Locator ASP.NET Application Using Google Maps API (Part 2) Happy Programming!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• How do I keep user input and rendering independent of the implementation environment?

  - by alex

  I'm writing a Tetris clone in JavaScript. I have a fair amount of experience in programming in general, but am rather new to game development. I want to separate the core game code from the code that would tie it to one environment, such as the browser. My quick thoughts led me to having the rendering and input functions external to my main game object. I could pass the current game state to the rendering method, which could render using canvas, elements, text, etc. I could also map input to certain game input events, such as move piece left, rotate piece clockwise, etc. I am having trouble designing how this should be implemented in my object. Should I pass references to functions that the main object will use to render and process user input? For example... var TetrisClone = function(renderer, inputUpdate) { this.renderer = renderer || function() {}; this.inputUpdate = input || function() {}; this.state = {}; }; TetrisClone.prototype = { update: function() { // Get user input via function passed to constructor. var inputEvents = this.inputUpdate(); // Update game state. // Render the current game state via function passed to constructor. this.renderer(this.state); } }; var renderer = function(state) { // Render blocks to browser page. } var inputEvents = {}; var charCodesToEvents = { 37: "move-piece-left" /* ... */ }; document.addEventListener("keypress", function(event) { inputEvents[event.which] = true; }); var inputUpdate = function() { var translatedEvents = [], event, translatedEvent; for (event in inputEvents) { if (inputEvents.hasOwnProperty(event)) { translatedEvent = charCodesToEvents[event]; translatedEvents.push(translatedEvent); } } inputEvents = {}; return translatedEvents; } var game = new TetrisClone(renderer, inputUpdate); Is this a good game design? How would you modify this to suit best practice in regard to making a game as platform/input independent as possible?

  Read the article

• How do you feel about being asked to code during an interview?

  - by Mystere Man

  I have seen a lot of comments about good interview questions and puzzles to require potential developers to solve during the interview process. I have personally had several interviews in which the interviewer has asked me to write some piece of code or solve a problem during the interview, and I have always performed very poorly in these "tests". The reason is simple, as a developer who spends my days talking to computers, I find I have to prepare myself and "switch gears" to be in "interview mode". I prepare myself to make a good impression. When I'm programming, I'm very focused and am totally different from when I'm being "interpersonal". I just can't get into "the zone" when I'm also having to be a charming and witty potential employee. I feel that by asking a developer to prove his skills during an interview, all you're doing is finding out if they can code under pressure, and at the drop of a hat. It has almost no ability to determine how you would perform in a "real life" development situation. Maybe, if you're looking for someone that can code and chat at the same time, i can see how that would be beneficial. But I think you overlook potential candidates that simply do not perform well in such an artificial environment. While I appreciate that a potential employer wants to see what I can do, I don't think an interview is the place for such a test. I mean, suppose a job for an over the road trucker required that you drive while being interviewed. How does that really end well? So I'm curious as to what others think about such situations. Have you failed interviews because you were not in the right frame of mind? Have you failed to make a good interpersonal impression because you were too distracted trying to solve the problem? If you're a hiring manager, or someone that gives interviews, do you even think about such things? Is it really important that someone perform well in an interview? EDIT: To clarify, I'm not against testing applicants. My concern is about testing during an interview. See also: What are the pros and cons for the employer of code questions during an interview? looking at this from the interviewer's point of view.

  Read the article

• Usage of Pirated software at a company

  - by hakesh

  Hi, I am redirected from stack over flow since the topic is ethics rather than about programming. Thank you for letting me know that. and please give me advices. So, I started to work at a company as an engineer a couple of months ago. It's a small company and what they basically do is answering service on phones. Now they are switching from normal phones to IP phones so that computers take more important place in the work. However, all the computers used by workers are equipped with pirated software ,even their operating systems are. Moreover, they don't even buy one license to make copies for other computers. In other words, they do not spend any money for the software in office. I am not saying copying a licensed one is legit, but the situation is too much. There is one guy who did installing those pirated soft. He does not feel any sense of guilt and even justified when I asked about it. and he is not even a specialist. He just searched on the internet to install pirated software. Our boss does not have any knowledge of computers, so he took cheaper way. How do you guys think about this? Since I am still new to the company, I am not doing maintenance or managing on those cracked computers. But I have to use those software daily. And later on I will be doing support, help desk kind of staff. I really don't want to take responsibility for operating pirated software. and from an aspect of developer and engineer, pirated software are not able to get legal support and it may work unexpectedly. So, I am thinking about changing job. Am I thinking too much? should I wait until I have more credit from the boss and try to change his policy? So far, the boss does not take any words from me. Any opinions are welcome. Thank you

  Read the article

• Agile team with no dedicated Tester members. Insane or efficient?

  - by MetaFight

  I'm a software developer. I've been thinking a lot about the efficiency of the Software Testers I've worked with so far in my career. In fact, I've been thinking a lot about the Software Testers role in general and have reached a potentially contentious conclusion: Non-developer Software Testers staff are less efficient at software testing than developers. Now, before everyone gets upset, hear me out. This isn't mere opinion: Software Testing and Software Development both require a lot of skills in common: Problem solving Thinking about corner cases Analytical skills The ability to define clear and concise step-by-step scenarios What developers have in addition to this is the ability to automate their tests. Yes, I know non-dev testers can automate their tests too, but that often then becomes a test maintenance issue. Because automating UI tests is essentially programming, non-dev members encounter all the same difficulties software developers encounter: Copy-pasta, lack of code reusibility/maintainability, etc. So, I was wondering. Why not replace all non-dev roles with developer roles? Developers have the skills required to perform Software Testing tasks, and they have the skills to automate tests and keep them maintainable. Would the following work: Hire a bunch of developers and split them into 2 roles: Software developers Software developers doing testing (some manual, mostly automated by writing integration tests, unit tests, etc) Software developers doing application support. (I've removed this as it is probably a separate question altogether) And, in our case since we're doing Agile development, rotate the roles every sprint or two. Also, if at all possible, try to have people spend their Developer stints and Testing stints on different projects. Ideally you would want to reduce the turnover rate per rotation. So maybe you could have 2 groups and make sure the rotation cycles of the groups are elided. So, for example, if each rotation was two sprints long, the two groups would have their rotations 1 sprint apart. That way there's only a 50% turn-over rate per sprint. Am I crazy, or could this work? (Obviously a key component to this working is that all devs want to be in the 3 roles. Let's assume I'm starting a new company and I can hire these ideal people) Edit I've removed the phrase "QA", as apparently we are using it incorrectly where I work.

  Read the article

• How are software projects 'typically' managed/deployed

  - by rguilbault

  My company is evaluating adopting off-the-shelf ALM products to aid in our development lifecycle; we currently use our own homegrown solutions to manage requirements gathering, specification documentation, testing, etc. One of the issues I am having is that we have what we call a pipeline, which consists of particular stops: [Source] - [QC] - [Production] At the first stop, the developer works out a solution to some requested change and performs individual testing. When that process is complete (and peer review has been performed), our ALM system physically moves the affected programs from the [Source] runtime environment to the [QC] runtime environment. You can think of this as analogous to moving some web pages from the 'test' server to the 'live' server, where QC personnel can bang on the system and complain that the developer has it all wrong ;-) Once QC signs off that the changes are working, the system again moves the code along to the next stage, where additional testing is performed, etc. I have been searching the internet for a few days trying to find how the process is accomplished anywhere else -- I have read a bit about builds, automated testing, various ALM products, etc. but nowhere does any of this state how builds interact with initial change requests, what the triggers are, how dependencies are managed, how the various forms of testing are accommodated (e.g. unit testing, integration testing, regression testing), etc. Can anyone point me to any resources or attempt to explain (generically) how a change could/should be tracked and moved though the development lifecycle? I'd be very appreciative. To keep things consistent, let's say that we have a project called Calculator, which we want to add support for the basic trigonometric functions: sine, cosine and tangent. I'm open to reorganizing the company however we need to in order to accomplish due diligence testing and we can suppose that any tools are available for use (if that helps to illustrate the process). To start things off, I think I understand this much: we document the requirements, e.g.: support sine, cosine and tangent functions we create some type of change request/work order to assign to programming coding takes place, commits are made to version control peer review commences programmer marks the work order as completed? ... now what? How does QC do their thing? Would they perform testing before closing the 'work order'?

  Read the article

• Should I use my own public API on my site (via JS)?

  - by newboyhun

  First of all, this question is far more different other 'public api questions' like this: Should a website use its own public API?, second, sorry for my English. You can find the question summarized at the bottom of this question. What I want to achieve is a big website with a public api, so who like programming (like me) and likes my website, can replicate my website's data with a much better approach (of course with some restrictions). Almost everything could be used by the public API. Because of this, I was thinking about making the whole website AJAX driven. There would be parts of the API which would be limited only to my website (domain), like login, registering. There would be only an INTERFACE on the client side, which would use the public and private API to make this interface working. The website would be ONLY CLIENT SIDE, well, I mean, the website would only use AJAX to use the api. How do I imagine this? The website would be like a mobile application, the application only sending a request to a webserver, which returns a json, the application parses it, and uses it to advance in the application. (e.g.: login) My thoughts: Pros: The whole website is built up by javascript, this means I don't need to transfer the html to the client, saving bandwidth. (I hope so) Anyone can use up the data of my website to make their own cool things. (Is this a con or pro? O_O) The public API is always in use, so I can see if there are any error. Cons: Without Javascript the website is unusable. The bad guys easily can load the server with requesting too much data (like Request Per Second 10000), but this can be countered via limiting this with some PHP code and logging. Probably much more work So the question in some words is: Should I build my website around my own api? Is it good to work only on the client side? Is this good for a big website? (e.x.: facebook, yeah facebook is a different story, but could it run with an 'architecture' like this?)

  Read the article

• Java EE 6?????????????? &quot;?&quot;????? ?????????????|WebLogic Channel|??????

  - by ???02

  ?Oracle WebLogic Server 12c??????????????????????Java EE?????Java EE 6??????????????????????????????Java EE 6?????????WebLogic Server 12c??????????Java????????????????????? 1?25????????Oracle WebLogic Server 12c Forum - ????????Java??????????? -?????WebLogic Server 12c??????? Java EE 6?? ~Java EE 6???????????????????~????????·???????????????????????????Java?????????????Java EE 6?WebLogic Server??????????????2??????????(???)??1????????Java EE????????????·?????????2????　???·??????????????·???Java?????????????????Java EE 5?????????????UFJ???????????????IT??????? ????????????????????????WebLogic Server???????????????????????????????????·??????????????????????????IT???????????·?????Publickey??????????????3????????????????????????????　??WebLogic Server?Java EE??????????????????????????????2??????2011?9???????????????Java EE?????????????????????????Java EE?????????????????????????????????Java EE??????????????????????????????????????????Java EE??????????????·????????????????????????????????????????????????¦?????WebLogic & Java EE???????????????　?????????Java EE?????????????　?????????·?????????????????2011?10???????????????????JavaOne 2011?????????????Publickey???????Java EE???????·????????????????????????????????????????????????Java EE?????????????????????????　JavaOne 2011???????????(??????)?????Java???????????????????????Java??????????????????????????????????Java EE 6????????? ????????　??????·?????????????????????????????????Java EE 6????????????WebLogic Server 12c??????Java EE?????Java EE 6??????????????????Java????????????????????????????????Java??????????????????????????　??????????????????Java EE 6??Java EE?????????????????????????　?J2EE 1.4???Java EE???????????????????????????????????????Java EE 5?????????Java EE 6???????????????????????????????????????????????????Struts?Spring????????????????????????????????????????????????????(???)　????????????????????????????JavaServer Faces(JSF)??????????????????????????????????????????????Java EE 6?????JSF 2.0?????????????????????????????????·?????????????????JSR-299:Context and Dependency Injection for Java EE Platform(CDI)????????????????????·??????????????????Java EE 6?????????1???????????????????????????　????????Java EE 6??????????4????????????????????????????????????????????????????????????????????????????????(IDE)?????????????????　1?????????????????????????????????????????????Java EE 7??8????????????Java EE 6????????????????????????????????????????????????　?????????????????????????????????????????????????????????Java EE?????????????????????????(???)??????????????　3??????????????????????????????????????????JAX-RS???WS-I Basic Profile????JAX-WS??????????????????　???4???IDE???????????NetBeans???????????????????Java EE 6?NetBeans?GlassFish??????????????????????Eclipse????IDE??????????????????????????????　????????????Java EE 6???????????????·??????????????????????????????????????????????????????????????????????　?Java EE 5???????????·?????3??(???)????????????????????????????????????????3????????????????????????????????Java EE 6???????????????????????CDI?????API???????????????????????Ruby on Rails?????????????????????????????????????????????????????????????(???)　???J2EE 1.4?????????????Java EE 6?????????????????????????????????????????????????Java EE 6????????????????????????????????????????????????????·????????WAR??????????????????????Java EE 6????????????????????????????????????J2EE 1.4??????10??1????????????????????????????Java EE???Java EE 6???????????????????　??????????????·???????????Java EE??????????J2EE 1.4?????????????????????"????Java EE??"???????????????Java EE 6???????????????????????????????　?????J2EE 1.4???????Java EE 6???????????????????????????????????????????Java EE?????????????????????????????????????????????????　??????????UFJ???????????????????????????Java EE 5????????????????????????????????????????????????????????????????????????　??Java EE 5????????J2EE 1.4??????????????POJO???????????????????????????????????????????????????????Java EE 5???????????????????????????????????????????????????????????　???J2EE 1.4????????????????Java EE 6????????????????????Dependency Injection(DI)?Aspect Oriented Programming(AOP)??????????????????????????(???)¦??????UFJ??????????????????????·?????WebLogic Server????????――????? ?????? ????? 2011?????　?????????????????????????????????????????????????????Java EE 6??????????????????????????(????????·???????????????????)???????????Java EE 6???????????　?????J2EE 1.4??Java EE 6????????????????????????????????J2EE 1.4+???????????????????????????????????????????????????????????????　????Spring????????????????????????????????????????"???"??????Java EE 6??????????????????????????????????????????　?Spring???????????????????????????????????????????????Java EE 6???????????????????EJB 3????????????????????????????EJB 3????????Java EE 6??????????????????????EJB?????????????????????????EJB????????????????(???)　????????JSF 2.0?Facelet???????????????????????????????????????????????????Struts?????????????JSF 2.0+Facelet???????????? "???????????"??"????????"?????????????????????????????????????????　?????????????????????????????????Java EE?????????Java EE 6????????????????????Java EE??????????????"??"?"???????"????????????????????????????????????????Java EE 6???????"?????????"????????????????????????????????????????????Java EE 6??????1???????Java EE?????????????????????????????　???????Java EE??????.NET??????????????????????Web????/????????·???????????????????????????????.NET????????????????????????????????Spring?Ruby on Rails???????????????Java EE 6??????????????????????????????????!???????????????????　????????????????????????Java EE?????????????????????????? Java EE????????????? WebLogic Server??????――??????·???????????????????????????????????????3?(?????)???

  Read the article

• Should the 12-String be in it's own class and why?

  - by MayNotBe

  This question is regarding a homework project in my first Java programming class (online program). The assignment is to create a "stringed instrument" class using (among other things) an array of String names representing instrument string names ("A", "E", etc). The idea for the 12-string is beyond the scope of the assignment (it doesn't have to be included at all) but now that I've thought of it, I want to figure out how to make it work. Part of me feels like the 12-String should have it's own class, but another part of me feels that it should be in the guitar class because it's a guitar. I suppose this will become clear as I progress but I thought I would see what kind of response I get here. Also, why would they ask for a String[] for the instrument string names? Seems like a char[] makes more sense. Thank you for any insight. Here's my code so far (it's a work in progress): public class Guitar { private int numberOfStrings = 6; private static int numberOfGuitars = 0; private String[] stringNotes = {"E", "A", "D", "G", "B", "A"}; private boolean tuned = false; private boolean playing = false; public Guitar(){ numberOfGuitars++; } public Guitar(boolean twelveString){ if(twelveString){ stringNotes[0] = "E, E"; stringNotes[1] = "A, A"; stringNotes[2] = "D, D"; stringNotes[3] = "G, G"; stringNotes[4] = "B, B"; stringNotes[5] = "E, E"; numberOfStrings = 12; } } public int getNumberOfStrings() { return numberOfStrings; } public void setNumberOfStrings(int strings) { if(strings == 12 || strings == 6) { if(strings == 12){ stringNotes[0] = "E, E"; stringNotes[1] = "A, A"; stringNotes[2] = "D, D"; stringNotes[3] = "G, G"; stringNotes[4] = "B, B"; stringNotes[5] = "E, E"; numberOfStrings = strings; } if(strings == 6) numberOfStrings = strings; }//if else System.out.println("***ERROR***Guitar can only have 6 or 12 strings***ERROR***"); } public void getStringNotes() { for(int i = 0; i < stringNotes.length; i++){ if(i == stringNotes.length - 1) System.out.println(stringNotes[i]); else System.out.print(stringNotes[i] + ", "); }//for }

  Read the article

• What is the standard term for my role?

  - by sigil

  I'm doing work that involves writing code and managing developers in a "special projects" division of a large company. I'd like to define my role better and figure out if there's an industry standard term for what I do, so that it will be easier for me to research best practices and work on a career path What I do all day: A macro that connects an Excel sheet to an Access database is acting funny; I get called in to figure out what's happening and debug it. Someone needs data extracted from a bunch of files on Sharepoint. I figure out a client-side solution because I'm not authorized to do anything server-side and getting IT to do anything would take several months and need a business case. A manager wants a new data entry tool for their team. I interview the manager and team members to work out the functional requirements, then design/develop/test the application. Someone needs a VBA script to crunch some data for their presentation that's due in two hours. I drop everything I'm doing to hack out a quick script and run the analysis, without much in the way of testing. A developer has been hired to build a database for one of the teams, since I'm working on too many different things and don't have time to take this project on in the timeframe required. I direct his work and push him to meet certain deadlines, interview stakeholders to get more info that will help him figure out how to build the necessary forms, and modify the functional requirements of the database to fit in the timeframe. Someone wants to load a set of data into a GIS system and set up an ongoing refresh and reporting of this data set. I facilitate the conversation between the GIS developers and the owners of this data set, and design a demo application as proof of concept. It's kind of an "all-purpose programming and IT management" position, but it's not officially IT because the company has an actual IT department with a rigorously defined system of submitting requests, developing code, and managing projects. What I do, I guess, is more of a handyman job, where stuff falls to me because I'm the geekiest one in the room. Is there a standard term in the software world for what I do?

  Read the article

• Should the 12-String be in it's own class and why? Java

  - by MayNotBe

  This is my first question here. I will amend it as instructed. This is regarding a homework project in my first Java programming class (online program). The assignment is to create a "stringed instrument" class using (among other things) an array of String names representing instrument string names ("A", "E", etc). The idea for the 12-string is beyond the scope of the assignment (it doesn't have to be included at all) but now that I've thought of it, I want to figure out how to make it work. Part of me feels like the 12-String should have it's own class, but another part of me feels that it should be in the guitar class because it's a guitar. I suppose this will become clear as I progress but I thought I would see what kind of response I get here. Also, why would they ask for a String[] for the instrument string names? Seems like a char[] makes more sense. Thank you for any insight. Here's my code so far (it's a work in progress): public class Guitar { private int numberOfStrings = 6; private static int numberOfGuitars = 0; private String[] stringNotes = {"E", "A", "D", "G", "B", "A"}; private boolean tuned = false; private boolean playing = false; public Guitar(){ numberOfGuitars++; } public Guitar(boolean twelveString){ if(twelveString){ stringNotes[0] = "E, E"; stringNotes[1] = "A, A"; stringNotes[2] = "D, D"; stringNotes[3] = "G, G"; stringNotes[4] = "B, B"; stringNotes[5] = "E, E"; numberOfStrings = 12; } } public int getNumberOfStrings() { return numberOfStrings; } public void setNumberOfStrings(int strings) { if(strings == 12 || strings == 6) { if(strings == 12){ stringNotes[0] = "E, E"; stringNotes[1] = "A, A"; stringNotes[2] = "D, D"; stringNotes[3] = "G, G"; stringNotes[4] = "B, B"; stringNotes[5] = "E, E"; numberOfStrings = strings; } if(strings == 6) numberOfStrings = strings; }//if else System.out.println("***ERROR***Guitar can only have 6 or 12 strings***ERROR***"); } public void getStringNotes() { for(int i = 0; i < stringNotes.length; i++){ if(i == stringNotes.length - 1) System.out.println(stringNotes[i]); else System.out.print(stringNotes[i] + ", "); }//for }

  Read the article

• Plagued by multithreaded bugs

  - by koncurrency

  On my new team that I manage, the majority of our code is platform, TCP socket, and http networking code. All C++. Most of it originated from other developers that have left the team. The current developers on the team are very smart, but mostly junior in terms of experience. Our biggest problem: multi-threaded concurrency bugs. Most of our class libraries are written to be asynchronous by use of some thread pool classes. Methods on the class libraries often enqueue long running taks onto the thread pool from one thread and then the callback methods of that class get invoked on a different thread. As a result, we have a lot of edge case bugs involving incorrect threading assumptions. This results in subtle bugs that go beyond just having critical sections and locks to guard against concurrency issues. What makes these problems even harder is that the attempts to fix are often incorrect. Some mistakes I've observed the team attempting (or within the legacy code itself) includes something like the following: Common mistake #1 - Fixing concurrency issue by just put a lock around the shared data, but forgetting about what happens when methods don't get called in an expected order. Here's a very simple example: void Foo::OnHttpRequestComplete(statuscode status) { m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } So now we have a bug in which Shutdown could get called while OnHttpNetworkRequestComplete is occuring on. A tester finds the bug, captures the crash dump, and assigns the bug to a developer. He in turn fixes the bug like this. void Foo::OnHttpRequestComplete(statuscode status) { AutoLock lock(m_cs); m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { AutoLock lock(m_cs); m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } The above fix looks good until you realize there's an even more subtle edge case. What happens if Shutdown gets called before OnHttpRequestComplete gets called back? The real world examples my team has are even more complex, and the edge cases are even harder to spot during the code review process. Common Mistake #2 - fixing deadlock issues by blindly exiting the lock, wait for the other thread to finish, then re-enter the lock - but without handling the case that the object just got updated by the other thread! Common Mistake #3 - Even though the objects are reference counted, the shutdown sequence "releases" it's pointer. But forgets to wait for the thread that is still running to release it's instance. As such, components are shutdown cleanly, then spurious or late callbacks are invoked on an object in an state not expecting any more calls. There are other edge cases, but the bottom line is this: Multithreaded programming is just plain hard, even for smart people. As I catch these mistakes, I spend time discussing the errors with each developer on developing a more appropriate fix. But I suspect they are often confused on how to solve each issue because of the enormous amount of legacy code that the "right" fix will involve touching. We're going to be shipping soon, and I'm sure the patches we're applying will hold for the upcoming release. Afterwards, we're going to have some time to improve the code base and refactor where needed. We won't have time to just re-write everything. And the majority of the code isn't all that bad. But I'm looking to refactor code such that threading issues can be avoided altogether. One approach I am considering is this. For each significant platform feature, have a dedicated single thread where all events and network callbacks get marshalled onto. Similar to COM apartment threading in Windows with use of a message loop. Long blocking operations could still get dispatched to a work pool thread, but the completion callback is invoked on on the component's thread. Components could possibly even share the same thread. Then all the class libraries running inside the thread can be written under the assumption of a single threaded world. Before I go down that path, I am also very interested if there are other standard techniques or design patterns for dealing with multithreaded issues. And I have to emphasize - something beyond a book that describes the basics of mutexes and semaphores. What do you think? I am also interested in any other approaches to take towards a refactoring process. Including any of the following: Literature or papers on design patterns around threads. Something beyond an introduction to mutexes and semaphores. We don't need massive parallelism either, just ways to design an object model so as to handle asynchronous events from other threads correctly. Ways to diagram the threading of various components, so that it will be easy to study and evolve solutions for. (That is, a UML equivalent for discussing threads across objects and classes) Educating your development team on the issues with multithreaded code. What would you do?

  Read the article

< Previous Page | 532 533 534 535 536 537 538 539 540 541 542 543  | Next Page >