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  • Building a project in VS that depends on a static and dynamic library

    - by fg nu
    Noob noobin'. I would appreciate some very careful handholding in setting up an example in Visual Studio 2010 Professional where I am trying to build a project which links: a previously built static library, for which the VS project folder is "C:\libjohnpaul\" a previously built dynamic library, for which the VS project folder is "C:\libgeorgeringo\" These are listed as Recipes 1.11, 1.12 and 1.13 in the C++ Cookbook. The project fails to compile for me with unresolved dependencies (see details below), and I can't figure out why. Project 1: Static Library The following are the header and source files that were compiled in this project. I was able to compile this project fine in VS2010, to the named standard library "libjohnpaul.lib" which lives in the folder ("C:/libjohnpaul/Release/"). // libjohnpaul/john.hpp #ifndef JOHN_HPP_INCLUDED #define JOHN_HPP_INCLUDED void john( ); // Prints "John, " #endif // JOHN_HPP_INCLUDED // libjohnpaul/john.cpp #include <iostream> #include "john.hpp" void john( ) { std::cout << "John, "; } // libjohnpaul/paul.hpp #ifndef PAUL_HPP_INCLUDED #define PAUL_HPP_INCLUDED void paul( ); // Prints " Paul, " #endif // PAUL_HPP_INCLUDED // libjohnpaul/paul.cpp #include <iostream> #include "paul.hpp" void paul( ) { std::cout << "Paul, "; } // libjohnpaul/johnpaul.hpp #ifndef JOHNPAUL_HPP_INCLUDED #define JOHNPAUL_HPP_INCLUDED void johnpaul( ); // Prints "John, Paul, " #endif // JOHNPAUL_HPP_INCLUDED // libjohnpaul/johnpaul.cpp #include "john.hpp" #include "paul.hpp" #include "johnpaul.hpp" void johnpaul( ) { john( ); paul( ); Project 2: Dynamic Library Here are the header and source files for the second project, which also compiled fine with VS2010, and the "libgeorgeringo.dll" file lives in the directory "C:\libgeorgeringo\Debug". // libgeorgeringo/george.hpp #ifndef GEORGE_HPP_INCLUDED #define GEORGE_HPP_INCLUDED void george( ); // Prints "George, " #endif // GEORGE_HPP_INCLUDED // libgeorgeringo/george.cpp #include <iostream> #include "george.hpp" void george( ) { std::cout << "George, "; } // libgeorgeringo/ringo.hpp #ifndef RINGO_HPP_INCLUDED #define RINGO_HPP_INCLUDED void ringo( ); // Prints "and Ringo\n" #endif // RINGO_HPP_INCLUDED // libgeorgeringo/ringo.cpp #include <iostream> #include "ringo.hpp" void ringo( ) { std::cout << "and Ringo\n"; } // libgeorgeringo/georgeringo.hpp #ifndef GEORGERINGO_HPP_INCLUDED #define GEORGERINGO_HPP_INCLUDED // define GEORGERINGO_DLL when building libgerogreringo.dll # if defined(_WIN32) && !defined(__GNUC__) # ifdef GEORGERINGO_DLL # define GEORGERINGO_DECL _ _declspec(dllexport) # else # define GEORGERINGO_DECL _ _declspec(dllimport) # endif # endif // WIN32 #ifndef GEORGERINGO_DECL # define GEORGERINGO_DECL #endif // Prints "George, and Ringo\n" #ifdef __MWERKS__ # pragma export on #endif GEORGERINGO_DECL void georgeringo( ); #ifdef __MWERKS__ # pragma export off #endif #endif // GEORGERINGO_HPP_INCLUDED // libgeorgeringo/ georgeringo.cpp #include "george.hpp" #include "ringo.hpp" #include "georgeringo.hpp" void georgeringo( ) { george( ); ringo( ); } Project 3: Executable that depends on the previous libraries Lastly, I try to link the aforecompiled static and dynamic libraries into one project called "helloBeatlesII" which has the project directory "C:\helloBeatlesII" (note that this directory does not nest the other project directories). The linking process that I did is described below: To the "helloBeatlesII" solution, I added the solutions "libjohnpaul" and "libgeorgeringo"; then I changed the properties of the "helloBeatlesII" project to additionally point to the include directories of the other two projects on which it depends ("C:\libgeorgeringo\libgeorgeringo" & "C:\libjohnpaul\libjohnpaul"); added "libgeorgeringo" and "libjohnpaul" to the project dependencies of the "helloBeatlesII" project and made sure that the "helloBeatlesII" project was built last. Trying to compile this project gives me the following unsuccessful build: 1------ Build started: Project: helloBeatlesII, Configuration: Debug Win32 ------ 1Build started 10/13/2012 5:48:32 PM. 1InitializeBuildStatus: 1 Touching "Debug\helloBeatlesII.unsuccessfulbuild". 1ClCompile: 1 helloBeatles.cpp 1ManifestResourceCompile: 1 All outputs are up-to-date. 1helloBeatles.obj : error LNK2019: unresolved external symbol "void __cdecl georgeringo(void)" (?georgeringo@@YAXXZ) referenced in function _main 1helloBeatles.obj : error LNK2019: unresolved external symbol "void __cdecl johnpaul(void)" (?johnpaul@@YAXXZ) referenced in function _main 1E:\programming\cpp\vs-projects\cpp-cookbook\helloBeatlesII\Debug\helloBeatlesII.exe : fatal error LNK1120: 2 unresolved externals 1 1Build FAILED. 1 1Time Elapsed 00:00:01.34 ========== Build: 0 succeeded, 1 failed, 2 up-to-date, 0 skipped ========== At this point I decided to call in the cavalry. I am new to VS2010, so in all likelihood I am missing something straightforward.

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  • Creating my first F# program in my new &ldquo;Expert F# Book&rdquo;

    - by MarkPearl
    So I have a brief hour or so that I can dedicate today to reading my F# book. It’s a public holiday and my wife’s birthday and I have a ton of assignments for UNISA that I need to complete – but I just had to try something in F#. So I read chapter 1 – pretty much an introduction to the rest of the book – it looks good so far. Then I get to chapter 2, called “Getting Started with F# and .NET”. Great, there is a code sample on the first page of the chapter. So I open up VS2010 and create a new F# console project and type in the code which was meant to analyze a string for duplicate words… #light let wordCount text = let words = Split [' '] text let wordset = Set.ofList words let nWords = words.Length let nDups = words.Length - wordSet.Count (nWords, nDups) let showWordCount text = let nWords,nDups = wordCount text printfn "--> %d words in text" nWords printfn "--> %d duplicate words" nDups   So… bad start - VS does not like the “Split” method. It gives me an error message “The value constructor ‘Split’ is not defined”. It also doesn’t like wordSet.Count telling me that the “namespace or module ‘wordSet’ is not defined”. ??? So a bit of googling and it turns out that there was a bit of shuffling of libraries between the CTP of F# and the Beta 2 of F#. To have access to the Split function you need to download the F# PowerPack and hen reference it in your code… I download and install the powerpack and then add the reference to FSharp.Core and FSharp.PowerPack in my project. Still no luck! Some more googling and I get the suggestions I got were something like this…#r "FSharp.PowerPack.dll";; #r "FSharp.PowerPack.Compatibility.dll";; So I add the code above to the top of my Program.fs file and still no joy… I now get an error message saying… Error    1    #r directives may only occur in F# script files (extensions .fsx or .fsscript). Either move this code to a script file, add a '-r' compiler option for this reference or delimit the directive with '#if INTERACTIVE'/'#endif'. So what does that mean? If I put the code straight into the F# interactive it works – but I want to be able to use it in a project. The C# equivalent I would think would be the “Using” keyword. The #r doesn’t seem like it should be in the FSharp code. So I try what the compiler suggests by doing the following…#if INTERACTIVE #r "FSharp.PowerPack.dll";; #r "FSharp.PowerPack.Compatibility.dll";; #endif No luck, the Split method is still not recognized. So wait a second, it mentioned something about FSharp.PowerPack.Compatibility.dll – I haven’t added this as a reference to my project so I add it and remove the two lines of #r code. Partial success – the Split method is now recognized and not underlined, but wordSet.Count is still not working. I look at my code again and it was a case error – the original wordset was mistyped comapred to the wordSet. Some case correction and the compiler is no longer complaining. So the code now seems to work… listed below…#light let wordCount text = let words = String.split [' '] text let wordSet = Set.ofList words let nWords = words.Length let nDups = words.Length - wordSet.Count (nWords, nDups) let showWordCount text = let nWords,nDups = wordCount text printfn "--> %d words in text" nWords printfn "--> %d duplicate words" nDups  So recap – if I wanted to use the interactive compiler then I need to put the #r code. In my mind this is the equivalent of me adding the the references to my project. If however I want to use the powerpack in a project – I just need to make sure that the correct references are there. I feel like a noob once again!

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  • How to convert my backup.cmd into something I can run in Linux?

    - by blade19899
    Back in the day when i was using windows(and a noob at everything IT) i liked batch scripting so much that i wrote a lot of them and one i am pretty proud of that is my backup.cmd(see below). I am pretty basic with the linux bash sudo/apt-get/sl/ls/locate/updatedb/etc... I don't really know the full power of the terminal. If you see the code below can i get it to work under (Ubuntu)linux :) by rewriting some of the windows code with the linux equivalent (btw:this works under xp/vista/7 | dutch/english) @echo off title back it up :home cls echo ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» echo º º echo º typ A/B for the options º echo º º echo ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹ echo º º echo º "A"=backup options º echo º º echo º "B"=HARDDISK Options º echo º º echo º º echo ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍŒ set /p selection=Choose: Goto %selection% :A cls echo ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» echo º º echo º typ 1 to start that backup º echo º º echo ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹ echo º º echo º "A"=backup options º echo º È1=Documents,Pictures,Music,Videos,Downloads º echo º º echo º "B"=HARDDISK Options º echo º º echo ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍŒ set /p selection=Choose: Goto %selection% :B cls echo ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» echo º º echo º typ HD to start the disk check º echo º º echo ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹ echo º º echo º "A"=backup options º echo º º echo º "B"=HARDDISK Options º echo º ÈHD=find and repair bad sectors º echo º º echo ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍŒ set /p selection=Choose: Goto %selection% :1 cls if exist "%userprofile%\desktop" (set desk=desktop) else (set desk=Bureaublad) if exist "%userprofile%\documents" (set docs=documents) else (set docs=mijn documenten) if exist "%userprofile%\pictures" (set pics=pictures) else (echo cant find %userprofile%\pictures) if exist "%userprofile%\music" (set mus=music) else (echo cant find %userprofile%\music) if exist "%userprofile%\Videos" (set vids=videos) else (echo cant find %userprofile%\videos) if exist "%userprofile%\Downloads" (set down=downloads) else (echo cant find %userprofile%\Downloads) cls echo. examples (D:\) (D:\Backup) (D:\Backup\18-4-2011) echo. echo. if there is no "D:\backup" folder then the folder will be created echo. set drive= set /p drive=storage: echo start>>backup.log echo Name:%username%>>backup.log echo Date:%date%>>backup.log echo Time:%time%>>backup.log echo ========================================%docs%===========================================>>backup.log echo %docs% echo Source:"%userprofile%\%docs%" echo Destination:"%drive%\%username%\%docs%" echo %time%>>backup.log xcopy "%userprofile%\%docs%" "%drive%\%username%\%docs%" /E /I>>Backup.log echo 20%% cls echo ========================================"%pics%"=========================================>>backup.log echo "%pics%" echo Source:"%userprofile%\%pics%" echo Destination:"%drive%\%username%\%pics%" echo %time%>>backup.log xcopy "%userprofile%\%pics%" "%drive%\%username%\%pics%" /E /I>>Backup.log echo 40%% cls echo ========================================"%mus%"=========================================>>backup.log echo "%mus%" echo Source:"%userprofile%\%mus%" echo Destination:"%drive%\%username%\%mus%" echo %time%>>backup.log xcopy "%userprofile%\%mus%" "%drive%\%username%\%mus%" /E /I>>Backup.log echo 60%% cls echo ========================================"%vids%"========================================>>backup.log echo %vids% echo Source:"%userprofile%\%vids%" echo Destination:"%drive%\%username%\%vids%" echo %time%>>backup.log xcopy "%userprofile%\%vids%" "%drive%\%username%\%vids%" /E /I>>Backup.log echo 80%% cls echo ========================================"%down%"========================================>>backup.log echo "%down%" echo Source:"%userprofile%\%down%" echo Destination:"%drive%\%username%\%down%" echo %time%>>backup.log xcopy "%userprofile%\%down%" "%drive%\%username%\%down%" /E /I>>Backup.log echo end>>backup.log echo %username% %date% %time%>>backup.log echo 100%% cls echo backup Compleet copy "backup.log" "%drive%\%username%" del "backup.log" pushd "%drive%\%username%" echo close backup.log to continue with backup script "backup.log" echo press any key to retun to the main menu pause>nul goto :home :HD echo finds and repairs bad sectors echo typ in harddisk letter (C: D: E:) set HD= set /p HD=Hard Disk: chkdsk %HD% /F /R /X pause goto :home

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  • PHP and Ruby: how to leverage both? and, is it worth it?

    - by dukeofgaming
    As you might have noticed from the title, this is not a "PHP or Ruby", or a "PHP vs. Ruby" question. This is a question on how to leverage PHP + Ruby in the same business. I myself am a PHP developer, I love the language because of its convenience and I specially love the ecosystem of resources that surround it: Joomla, Drupal, Wordpress, Symfony2, Doctrine2, etc. However, the language itself can be a little disappointing sometimes. OTOH, Ruby looks like a very beautiful language and —from studying it superficially in several aspects— I could say it is leaner than Python as a language per se. However, from what I've seen there is pretty much only RoR making noise, and I don't like RoR so much (mainly because its model layer). As Co-CEO and CTO at my company I'm trying to think outside of the box since I want to start to focus on the human side of technology and see if its sane to use both PHP and Ruby. Here are some random thoughts: Ruby folk seem to be generally better suited programmers than PHP folk (in terms of averages), I know the previous statement is somewhat baloney because very good and well architected PHP can be written, but I'd say the Ruby programmer culture is better than PHP's. The thing about Ruby is that it seems better suited for rapid development, I don't really know if this is only the case for RoR, but I do know that there are certain practices (perhaps not so good) like monkey patching that let business needs be satified quicker. From a marketing point of view (yep, sometimes you need to leverage the marketing BS for the sake of your company) Ruby seems better while PHP carries some stigmas. PHP 5.4 is bringing traits, and that is better/cleaner than mixins. That could really make PHP as lean as Ruby —or more— for certain stuff. Now, concretely, my questions: Would a PHP programmer want to learn Ruby?, I know I do, but conversely, would a Ruby programmer want to learn PHP?. What kinds of projects or situations would be better suited for Ruby that are not suited for PHP?. What is the actual ecosystem of Ruby?, aside from RoR, I have not seen other hyped technologies/frameworks (I've seen RSpec, but I confess being a total noob on what BDD really consists of and its implications). Supposing there are a certain type of projects ideal for Ruby, would there be a moment that its better to move it to PHP?. I know PHP can handle lots of stuff, but I've read that Ruby has its limitations when scaling (or is that RoR?, or is that baloney for both?). Finally and most importantly, would it be sane to maintain projects in two languages?, or is that just stupid. As I said, it looks like Ruby is leaner on the short term and that can make a project happen and succeed, but I'm not so sure about that on the long run. I'm looking for insights mainly from people that know well the strengths and weaknesses of the languages —preferably both of them— and Ruby's ecosystem in real practice, meaning: frameworks and applications like the ones I quoted from PHP's ecosystem. Best regards and thanks for your time.

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  • How would I handle input with a Game Component?

    - by Aufziehvogel
    I am currently having problems from finding my way into the component-oriented XNA design. I read an overview over the general design pattern and googled a lot of XNA examples. However, they seem to be right on the opposite site. In the general design pattern, an object (my current player) is passed to InputComponent::update(Player). This means the class will know what to do and how this will affect the game (e.g. move person vs. scroll text in a menu). Yet, in XNA GameComponent::update(GameTime) is called automatically without a reference to the current player. The only XNA examples I found built some sort of higher-level Keyboard engine into the game component like this: class InputComponent: GameComponent { public void keyReleased(Keys); public void keyPressed(Keys); public bool keyDown(Keys); public void override update(GameTime gameTime) { // compare previous state with current state and // determine if released, pressed, down or nothing } } Some others went a bit further making it possible to use a Service Locator by a design like this: interface IInputComponent { public void downwardsMovement(Keys); public void upwardsMovement(Keys); public bool pausedGame(Keys); // determine which keys pressed and what that means // can be done for different inputs in different implementations public void override update(GameTime); } Yet, then I am wondering if it is possible to design an input class to resolve all possible situations. Like in a menu a mouse click can mean "click that button", but in game play it can mean "shoot that weapon". So if I am using such a modular design with game components for input, how much logic is to be put into the InputComponent / KeyboardComponent / GamepadComponent and where is the rest handled? What I had in mind, when I heard about Game Components and Service Locator in XNA was something like this: use Game Components to run the InputHandler automatically in the loop use Service Locator to be able to switch input at runtime (i.e. let player choose if he wants to use a gamepad or a keyboard; or which shall be player 1 and which player 2). However, now I cannot see how this can be done. First code example does not seem flexible enough, as on a game pad you could require some combination of buttons for something that is possible on keyboard with only one button or with the mouse) The second code example seems really hard to implement, because the InputComponent has to know in which context we are currently. Moreover, you could imagine your application to be multi-layered and let the key-stroke go through all layers to the bottom-layer which requires a different behaviour than the InputComponent would have guessed from the top-layer. The general design pattern with passing the Player to update() does not have a representation in XNA and I also cannot see how and where to decide which class should be passed to update(). At most time of course the player, but sometimes there could be menu items you have to or can click I see that the question in general is already dealt with here, but probably from a more elobate point-of-view. At least, I am not smart enough in game development to understand it. I am searching for a rather code-based example directly for XNA. And the answer there leaves (a noob like) me still alone in how the object that should receive the detected event is chosen. Like if I have a key-up event, should it go to the text box or to the player?

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  • 12.04 making BCM4313 card work with aircrack-ng?

    - by Charles Forest
    I'm a real Linux Noob, just started using it (this month) and until now i had no issues. now i'm trying to set-up aircrack-ng on my laptop, but it seems like it's using the worst card possible (or almost) there is a TON of tutorial on this card (seems to be hell to set-up) i have tryed some, but i ended up uninstalling my drivers, messing with my desktops, and ended by having no more "X" to close my windows (i have no clue how i ended there) i just re-installed my linux (took me 2 hours to setup everything again), but now i'm a bit "Scared" to try tutorials randomly again. Right now it says the driver is wl, wich is not the one i want (AFAIK it's not supported) i'm not sure what kind of informations are needed, but here's what i think could be usefull. lspci -knn 00:00.0 Host bridge [0600]: Intel Corporation 2nd Generation Core Processor Family DRAM Controller [8086:0104] (rev 09) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: agpgart-intel 00:01.0 PCI bridge [0604]: Intel Corporation Xeon E3-1200/2nd Generation Core Processor Family PCI Express Root Port [8086:0101] (rev 09) Kernel driver in use: pcieport Kernel modules: shpchp 00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: i915 Kernel modules: i915 00:16.0 Communication controller [0780]: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 [8086:1c3a] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: mei Kernel modules: mei 00:1a.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 [8086:1c2d] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: ehci_hcd 00:1b.0 Audio device [0403]: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller [8086:1c20] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 00:1c.0 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 [8086:1c10] (rev b4) Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.3 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 [8086:1c16] (rev b4) Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.4 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 5 [8086:1c18] (rev b4) Kernel driver in use: pcieport Kernel modules: shpchp 00:1d.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 [8086:1c26] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: ehci_hcd 00:1f.0 ISA bridge [0601]: Intel Corporation HM65 Express Chipset Family LPC Controller [8086:1c49] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel modules: iTCO_wdt 00:1f.2 SATA controller [0106]: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller [8086:1c03] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: ahci 00:1f.3 SMBus [0c05]: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller [8086:1c22] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel modules: i2c-i801 01:00.0 3D controller [0302]: NVIDIA Corporation GF108 [GeForce GT 540M] [10de:0df4] (rev a1) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: nouveau Kernel modules: nouveau, nvidiafb WIRELESS CARD 02:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01) Subsystem: Wistron NeWeb Corp. Device [185f:051a] Kernel driver in use: wl Kernel modules: wl, bcma, brcmsmac REST... 03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168] (rev 06) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: r8169 Kernel modules: r8169 04:00.0 USB controller [0c03]: NEC Corporation uPD720200 USB 3.0 Host Controller [1033:0194] (rev 04) Subsystem: Samsung Electronics Co Ltd Device [144d:c0a5] Kernel driver in use: xhci_hcd Also, if i'm "screwed" with my hardware, just tell me.

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  • Multithreading 2D gravity calculations

    - by Postman
    I'm building a space exploration game and I've currently started working on gravity ( In C# with XNA). The gravity still needs tweaking, but before I can do that, I need to address some performance issues with my physics calculations. This is using 100 objects, normally rendering 1000 of them with no physics calculations gets well over 300 FPS (which is my FPS cap), but any more than 10 or so objects brings the game (and the single thread it runs on) to its knees when doing physics calculations. I checked my thread usage and the first thread was killing itself from all the work, so I figured I just needed to do the physics calculation on another thread. However when I try to run the Gravity.cs class's Update method on another thread, even if Gravity's Update method has nothing in it, the game is still down to 2 FPS. Gravity.cs public void Update() { foreach (KeyValuePair<string, Entity> e in entityEngine.Entities) { Vector2 Force = new Vector2(); foreach (KeyValuePair<string, Entity> e2 in entityEngine.Entities) { if (e2.Key != e.Key) { float distance = Vector2.Distance(entityEngine.Entities[e.Key].Position, entityEngine.Entities[e2.Key].Position); if (distance > (entityEngine.Entities[e.Key].Texture.Width / 2 + entityEngine.Entities[e2.Key].Texture.Width / 2)) { double angle = Math.Atan2(entityEngine.Entities[e2.Key].Position.Y - entityEngine.Entities[e.Key].Position.Y, entityEngine.Entities[e2.Key].Position.X - entityEngine.Entities[e.Key].Position.X); float mult = 0.1f * (entityEngine.Entities[e.Key].Mass * entityEngine.Entities[e2.Key].Mass) / distance * distance; Vector2 VecForce = new Vector2((float)Math.Cos(angle), (float)Math.Sin(angle)); VecForce.Normalize(); Force = Vector2.Add(Force, VecForce * mult); } } } entityEngine.Entities[e.Key].Position += Force; } } Yeah, I know. It's a nested foreach loop, but I don't know how else to do the gravity calculation, and this seems to work, it's just so intensive that it needs its own thread. (Even if someone knows a super efficient way to do these calculations, I'd still like to know how I COULD do it on multiple threads instead) EntityEngine.cs (manages an instance of Gravity.cs) public class EntityEngine { public Dictionary<string, Entity> Entities = new Dictionary<string, Entity>(); public Gravity gravity; private Thread T; public EntityEngine() { gravity = new Gravity(this); } public void Update() { foreach (KeyValuePair<string, Entity> e in Entities) { Entities[e.Key].Update(); } T = new Thread(new ThreadStart(gravity.Update)); T.IsBackground = true; T.Start(); } } EntityEngine is created in Game1.cs, and its Update() method is called within Game1.cs. I need my physics calculation in Gravity.cs to run every time the game updates, in a separate thread so that the calculation doesn't slow the game down to horribly low (0-2) FPS. How would I go about making this threading work? (any suggestions for an improved Planetary Gravity system are welcome if anyone has them) I'm also not looking for a lesson in why I shouldn't use threading or the dangers of using it incorrectly, I'm looking for a straight answer on how to do it. I've already spent an hour googling this very question with little results that I understood or were helpful. I don't mean to come off rude, but it always seems hard as a programming noob to get a straight meaningful answer, I usually rather get an answer so complex I'd easily be able to solve my issue if I understood it, or someone saying why I shouldn't do what I want to do and offering no alternatives (that are helpful). Thank you for the help!

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  • Libgdx 2D Game, Random generated World of random size, how to get mouse coordinates?

    - by Solom
    I'm a noob and English is not my mothertongue, so please bear with me! I'm generating a map for a Sidescroller out of a 2D-array. That is, the array holds different values and I create blocks based on that value. Now, my problem is to match mouse coordinates on screen with the actual block the mouse is pointing at. public class GameScreen implements Screen { private static final int WIDTH = 100; private static final int HEIGHT = 70; private OrthographicCamera camera; private Rectangle glViewport; private Spritebatch spriteBatch; private Map map; private Block block; ... @Override public void show() { camera = new OrthographicCamera(WIDTH, HEIGHT); camera.position.set(WIDTH/2, HEIGHT/2, 0); glViewport = new Rectangle(0, 0, WIDTH, HEIGHT); map = new Map(16384, 256); map.printTileMap(); // Debugging only spriteBatch = new SpriteBatch(); } @Override public void render(float delta) { // Clear previous frame Gdx.gl.glClearColor(1, 1, 1, 1 ); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); GL30 gl = Gdx.graphics.getGL30(); // gl.glViewport((int) glViewport.x, (int) glViewport.y, (int) glViewport.width, (int) glViewport.height); spriteBatch.setProjectionMatrix(camera.combined); camera.update(); spriteBatch.begin(); // Draw Map this.drawMap(); // spriteBatch.flush(); spriteBatch.end(); } private void drawMap() { for(int a = 0; a < map.getHeight(); a++) { // Bounds check (y) if(camera.position.y + camera.viewportHeight < a)// || camera.position.y - camera.viewportHeight > a) break; for(int b = 0; b < map.getWidth(); b++) { // Bounds check (x) if(camera.position.x + camera.viewportWidth < b)// || camera.position.x > b) break; // Dynamic rendering via BlockManager int id = map.getTileMap()[a][b]; Block block = BlockManager.map.get(id); if(block != null) // Check if Air { block.setPosition(b, a); spriteBatch.draw(block.getTexture(), b, a, 1 ,1); } } } } As you can see, I don't use the viewport anywhere. Not sure if I need it somewhere down the road. So, the map is 16384 blocks wide. One block is 16 pixels in size. One of my naive approaches was this: if(Gdx.input.isButtonPressed(Input.Buttons.LEFT)) { Vector3 mousePos = new Vector3(); mousePos.set(Gdx.input.getX(), Gdx.input.getY(), 0); camera.unproject(mousePos); System.out.println(Math.round(mousePos.x)); // *16); // Debugging // TODO: round // map.getTileMap()[mousePos.x][mousePos.y] = 2; // Draw at mouse position } I confused myself somewhere down the road I fear. What I want to do is, update the "block" (or rather the information in the Map/2D-Array) so that in the next render() there is another block. Basically drawing on the spriteBatch g So if anyone could point me in the right direction this would be highly appreciated. Thanks!

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  • Framework for Everything - Where to begin? [Longer post]

    - by SquaredSoft
    Back story of this question, feel free to skip down for the specific question Hello, I've been very interested in the idea of abstract programming the last few years. I've made about 30 attempts at creating a piece of software that is capable of almost anything you throw at it. I've undertook some attempts at this that have taken upwards of a year, while getting close, never releasing it beyond my compiler. This has been something I've always tried wrapping my head around, and something is always missing. With the title, I'm sure you're assuming, "Yes of course you noob! You can't account for everything!" To which I have to reply, "Why not?" To give you some background into what I'm talking about, this all started with doing maybe a shade of gray hat SEO software. I found myself constantly having to create similar, but slightly different sets of code. I've gone through as many iterations of way to communicate on http as the universe has particles. "How many times am I going to have to write this multi-threaded class?" is something I found myself asking a lot. Sure, I could create a class library, and just work with that, but I always felt I could optimize what I had, which often was a large undertaking and typically involved frequent use of the CRTL+A keyboard shortcut, mixed with the delete button. It dawned on me that it was time to invest in a plugin system. This would allow me to simply add snippets of code. as time went on, and I could subversion stuff out, and distribute small chunks of code, rather than something that encompasses only a specific function or design. This comes with its own complexity, of course, and by the time I had finished the software scope for this addition, it hit me that I would want to add to everything in the software, not just a new http method, or automation code for a specific website. Great, we're getting more abstract. However, the software that I have in my mind comes down to a quite a few questions regarding its execution. I have to have some parameters to what I am going to do. After writing what the perfect software would do in my mind, I came up with this as a list of requirements: Should be able to use networking A "Macro" or "Expression system" which would allow people to do something like : =First(=ParseToList(=GetUrl("http://www.google.com?q=helloworld!"), Template.Google)) Multithreaded Able to add UI elements through some type of XML -- People can make their own addons etc. Can use third party API through the plugins, such as Microsoft CRM, Exchange, etc. This would allow the software to essentially be used for everything. Really, any task you wish to automate, in a simple way. Making the UI was as also extremely hard. How do you do all of this? Its very difficult. So my question: With so many attempts at this, I'm out of ideas how to successfully complete this. I have a very specific idea in my mind, but I keep failing to execute it. I'm a self taught programmer. I've been doing it for years, and work professionally in it, but I've never encountered something that would be as complex and in-depth as a system which essentially does everything. Where would you start? What are the best practices for design? How can I avoid constantly having to go back and optimize my software. What can I do to generalize this and draw everything out to completion. These are things I struggle with. P.s., I'm using c# as my main language. I feel like in this example, I might be hitting the outer limit of the language, although, I don't know if that is the case, or if I'm just a bad programmer. Thanks for your time.

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  • SDL Bullet Movement

    - by Code Assasssin
    I'm currently working on my first space shooter, and I'm in the process of making my ship shoot some bullets/lasers. Unfortunately, I'm having a hard time getting the bullets to fly vertically. I'm a total noob when it comes to this so you might have a hard time understanding my code :/ // Position Bullet Function projectilex = x + 17; projectiley = y + -20; if(keystates[SDLK_SPACE]) { alive = true; } And here's my show function if(alive) { if(frame == 2) { frame = 0; } apply_surface(projectilex,projectiley,ShootStuff,screen,&lazers[frame]); frame++; projectiley + 1; } I'm trying to get the bullet to fly vertically... and I have no clue how to do that. I've tried messing with the y coordinate but that makes things worse. The laser/bullet just follows the ship :( How would I get it to fire at the starting position and keep going in a vertical line without it following the ship? int main( int argc, char* args[] ) { Player p; Timer fps; bool quit = false; if( init() == false ) { return 1; } //Load the files if( load_files() == false ) { return 1; } clip[ 0 ].x = 0; clip[ 0 ].y = 0; clip[ 0 ].w = 30; clip[ 0 ].h = 36; clip[ 1 ].x = 31; clip[ 1 ].y = 0; clip[ 1 ].w = 39; clip[ 1 ].h = 36; clip[ 2 ].x = 71; clip[ 2 ].y = 0; clip[ 2 ].w = 29; clip[ 2 ].h = 36; lazers [ 0 ].x = 0; lazers [ 0 ].y = 0; lazers [ 0 ].w = 3; lazers [ 0 ].h = 9; lazers [ 1 ].x = 5; lazers [ 1 ].y = 0; lazers [ 1 ].w = 3; lazers [ 1 ].h = 7; while( quit == false ) { fps.start(); //While there's an event to handle while( SDL_PollEvent( &event ) ) { p.handle_input(); //If a key was pressed //If the user has Xed out the window if( event.type == SDL_QUIT ) { //Quit the program quit = true; } } //Scroll background bgX -= 8; //If the background has gone too far if( bgX <= -GameBackground->w ) { //Reset the offset bgX = 0; } p.move(); apply_surface( bgX, bgY,GameBackground, screen ); apply_surface( bgX + GameBackground->w, bgY, GameBackground, screen ); apply_surface(0,0, FullHealthBar,screen); p.shoot(); p.show(); //Apply the message //Update the screen if( SDL_Flip( screen ) == -1 ) { return 1; } SDL_Flip(GameBackground); if( fps.get_ticks() < 1000 / FRAMES_PER_SECOND ) { SDL_Delay( ( 1000 / FRAMES_PER_SECOND ) - fps.get_ticks() ); } } //Clean up clean_up(); return 0; }

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  • 12.10 unable to install or even run from Live CD with nVidia GTX 580

    - by user99056
    I've used Ubuntu in the past (set up as web server, etc over in Iraq), so I'm not a 100% Linux Noob, however, I'm running into a brick wall here. I've got a machine I built when I got back to the US earlier this year, running Windows 7 Ultimate on it, and I've now got some free time and would like to transition over to Ubuntu full time. I've searched around in the forums, and there seems to be an issue with the nVidia graphics cards, so I've tried going to the EVGA site to see if I could find a new BIOS update for it and had no luck, so I'm back searching the forums here again and decided to just go ahead and post my question. My apologies if this is covered in another post and I was just unable to find it. I've found a few 'similar' posts, but nothing as bad as my issue. With the history aside, here is the actual detailed issue: I purchased a new SSD (Intel 520 SSD), arrived today, and I disconnect my old Windows 7 SSD. I had pre downloaded the ubuntu-12.10-desktop-amd64 earlier today and burned it to DVD. Upon inserting the Live CD into the computer and booting up, everything was fine up to the 'Run From Live CD' or 'Install Ubuntu Now' buttons. As I was sure I wanted to go ahead and make the switch, I selected the 'Install Now' from the right hand side. CD Spins up, black window pops up, and then the errors started: date/time GPU Lockup date/time Failed to idle channel 1 date/time PFIFO - playlist update failed date/time Failed to idle channel 2 date/time PFIFO - playlist update failed Thinking it might correct itself, I let it run and it would swap over to a GUI Screen that was locked up with major blurring/etc, then back to the command line with the errors. Eventually it said something along the lines of 'unknown status' and switched back to the GUI and froze. So, that's when I tried to see if I could find a BIOS upgrade for the nVidia GTX580 cards, and had no luck. So I thought, why not try to just run it from the Live CD and see if I can at least get a look at it, maybe if I could get it running try to do some sort of install from there and fix the driver issue. I rebooted, brought up the Live CD, and this time chose the left option / run from the CD. It brought me all the way in to the desktop, I saw my drives, the other icons, could move the mouse, etc for about 30 seconds and then it locked up completely. I've tried this a couple of times and get the same results every time. Hardware: Intel i7-3930K CPU @ 3.2GHz (12 CPUs) / MSI MS-7760 Motherboard / 32GB RAM / 2 x EVGA (nVidia) GeForce GTX 580 (4GB Ram each) So the question is: Is there any way to install 12.10 if you can't even get the Live CD to run (for more than 30 seconds)? My current hardware configuration is both of the GTX 580 cards have an SLI jumper on them, and I have 2 monitors on each card. (Ubuntu info obviously only shows on the main monitor from the failed installation and the attempt at running the Live CD). Perhaps opening the machine back up and removing the SLI Jumper and removing the other 3 monitors (so it only would have 1 video card with one monitor on it) would actually allow me to get 12.10 installed, then I could work on an nVidia Video Driver fix for the GTX 580, and then possibly hook up the other video card and monitors? Or is this something that they are currently aware of and may update with a future release in the next few days/weeks? Any thoughts or suggestions would be greatly appreciated, as I can't even try to fix the issue (assuming it is the nVidia drivers) if I can't even get it to install at all.

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  • PHP crashing (seg-fault) under mod_fcgi, apache

    - by Andras Gyomrey
    I've been programming a site using: Zend Framework 1.11.5 (complete MVC) PHP 5.3.6 Apache 2.2.19 CentOS 5.6 i686 virtuozzo on vps cPanel WHM 11.30.1 (build 4) Mysql 5.1.56-log Mysqli API 5.1.56 The issue started here http://stackoverflow.com/questions/6769515/php-programming-seg-fault. In brief, php is giving me random segmentation-faults. [Wed Jul 20 17:45:34 2011] [error] mod_fcgid: process /usr/local/cpanel/cgi-sys/php5(11562) exit(communication error), get unexpected signal 11 [Wed Jul 20 17:45:34 2011] [warn] [client 190.78.208.30] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server [Wed Jul 20 17:45:34 2011] [error] [client 190.78.208.30] Premature end of script headers: index.php About extensions. When i compile php with "--enable-debug" flag, i have to disable this line: zend_extension="/usr/local/IonCube/ioncube_loader_lin_5.3.so" Otherwise, the server doesn't accept requests and i get a "The connection with the server was reset". It is possible that i have to disable eaccelerator too because of the same reason. I still don't get why apache gets running it some times and some others not: extension="eaccelerator.so" Anyway, after i get httpd running, seg-faults can occurr randomly. If i don't compile php with "--enable-debug" flag, i can get DETERMINISTICALLY a php crash: <?php class Admin_DbController extends Controller_BaseController { public function updateSqlDefinitionsAction() { $db = Zend_Registry::get('db'); $row = $db->fetchRow("SHOW CREATE TABLE 222AFI"); } } ?> BUT if i compile php with "--enable-debug" flag, it's really hard to get this error. I must add some complexity to make it crash. I have to be doing many paralell requests for a few seconds to get a crash: <?php class Admin_DbController extends Controller_BaseController { public function updateSqlDefinitionsAction() { $db = Zend_Registry::get('db'); $tableList = $db->listTables(); foreach ($tableList as $tableName){ $row = $db->fetchRow("SHOW CREATE TABLE " . $db->quoteIdentifier($tableName)); file_put_contents( DB_DEFINITIONS_PATH . '/' . $tableName . '.sql', $row['Create Table'] . ';' ); } } } ?> Please notice this is the same script, but creating DDL for all tables in database rather than for one. It seems that if php is heavy loaded (with extensions and me doing many paralell requests) it's when i get php to crash. About starting httpd with "-X": i've tried. The thing is, it is already hard to make php crash with --enable-debug. With "-X" option (which only enables one child process) i can't do parallel requests. So i haven't been able to create to proper debug backtrace: https://bugs.php.net/bugs-generating-backtrace.php My concrete question is, what do i do to get a coredump? root@GWT4 [~]# httpd -V Server version: Apache/2.2.19 (Unix) Server built: Jul 20 2011 19:18:58 Cpanel::Easy::Apache v3.4.2 rev9999 Server's Module Magic Number: 20051115:28 Server loaded: APR 1.4.5, APR-Util 1.3.12 Compiled using: APR 1.4.5, APR-Util 1.3.12 Architecture: 32-bit Server MPM: Prefork threaded: no forked: yes (variable process count) Server compiled with.... -D APACHE_MPM_DIR="server/mpm/prefork" -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=128 -D HTTPD_ROOT="/usr/local/apache" -D SUEXEC_BIN="/usr/local/apache/bin/suexec" -D DEFAULT_PIDLOG="logs/httpd.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_LOCKFILE="logs/accept.lock" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="conf/mime.types" -D SERVER_CONFIG_FILE="conf/httpd.conf"

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  • Setting up a minimalist linux environment

    - by Nate
    All right, I've been messing around with various linux distros and a variety of window managers (I seem to change operating systems like most people change their pants), and I've gotten to the point where I know what I want but I'm not sure the best way to set it up. Here's what I want out of my programming machine: I don't want a status bar. I don't want a menu bar. When there are no windows open, the screen should show my desktop background and nothing else. I'll use alt+f2 to run things, and my shell prompt will tell me my battery life and the time. I'll open network controls and volume controls when I need them, no need for them to pollute the screen all the time. I want a good, simple terminal emulator. I'll be using it with tmux. It should have no title bar and, if possible, no app frame. It's ok if I have to run it in full screen mode to remove the app frame, but only if it still plays nicely with alt-tab and workspaces. I want a dirt-simple window manager. It needs to support transparency: I don't have a lot of screen real-estate and I often overlay the terminal on the browser and type out commands. I don't want a tiling-only system, for the above reason. Bonus points for tiling and overlaying. I'd like multiple workspaces. I prefer to have one gui per workspace. If I could 'pin' the terminal emulator to always show up in each workspace, that's bonus points. If not, I can have a terminal emulator in each workspace attached to the same tmux instance. I'd like a way to set up a keypress that always takes me to the current open terminal emulator. Currently, 90% of the time I only have two windows open: the terminal emulator and something else. In this scenario, alt-tab works like a toggle between the two. If I have another gui open (like a developer window with a web browser), this throws a wrench in my workflow. I'd like a way to assign, for example, 'super-T' to switch to the first open terminal emulator. Bonus points if I can also assign 'super-B' (or whatever) to switch to the first open browser. So far I've been messing around with gnome and tweaking it heavily to match my preferences, but that seems like overkill and I can never get it quite right. I've toyed with xmonad, but it's more for handling many windows, and I usually only have the two. and am considering fluxbox, but I was wondering if any of your minimalists out there had suggestions that might better match my workflow. I'm sick of fighting the window manager, I just want it to get out of my way. Edit: To make things clear, I am not considering switching to a mac/windows environment. I find programming in windows to be a bore, and I have no interest in buying new (read: mac) hardware. Thanks! -Nate

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  • Open-source and client-side IRC-Client

    - by user125197
    I'm administrating a homepage with an IRC-Webclient. At the moment, it uses a Java-client, modified to be SSL-compatible and compatible with whatever design I want to use. The usual PJIRC thing, with users wishes and concerns implemented (I'll give you SSL-PJIRC if you want - no problem. The login-script will be improved for IE6-support this weekend, means write the object tag if an old IE is found, that's it. Rest runs perfectly well). But still, the better user experience would be a client that only requires the user to enable JavaScript. So, before I go into rewriting and customizing a complete Java-IRC-solution, I'd like to ask some other people - after researching for half a year of time. The requirements are: a) Free hosting, no cgi-bin is acceptable. A lot of hosters also have CGI supported, but it doesn't allow IRC-access. So, seems you are limited to x10-hosting for CGI:IRC. b) Solution must be open source (not free as in free beer, but free as in free speech - I want to be able to read every line of the code). c) Hosting cannot be limited to Windows-hosting. Free operation systems (anything with Linux, BSD, whatever - I think you get what I mean) must be possible. d) No server-side technology. I'm limited to everything that runs client-side only. (Well, a Java-Applet does...). d) Solution must support SSL. e) The side must be able to move. Means, you register to a new free hoster, load your things up via FileZilla and the thing simply runs. No server-concerning implementations needed. f) Old browsers must be supported. From all my research, there are two ways a) Java-Applet b) Use HTML5-Websockets (it is impossible to use the JavaScript-library I found, as it depends on ActiveX - means, Windows hosting). b) means "you are going to enter very unstable content". I worked with HTML5 for month, and, well ... Though, HTML5 also is not suitable for older browsers (old browser support is an absolutely necessary requirement). PHP by the way is a server side solution ... so no line of PHP. My idea now was a Java Applet, and a fallback which again is embedded and proprietary, but only requieres JavaScript (wsirc or Mibbit are great here, whilst I prefer wsirc ... and zooming fonts that are plainly to small, but worse, cannot read the code). So my question is - with free hosting, not installation on server, plain upload - do you see and open source, complelety client-side, ssl-compatible way to use or write a client? This wouldn't be my first programming project, I'm not afraid of the code. If there was a way and I had to write it, even from scratch, I'd do. From all I know, there sadly is none. But maybe some experienced admin has an idea? Best Wishes, yetanotheruser Sry my English isn't perfect. It's enough for programming at least.

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  • Consume WCF Service InProcess using Agatha and WCF

    - by REA_ANDREW
    I have been looking into this lately for a specific reason.  Some integration tests I want to write I want to control the types of instances which are used inside the service layer but I want that control from the test class instance.  One of the problems with just referencing the service is that a lot of the time this will by default be done inside a different process.  I am using StructureMap as my DI of choice and one of the tools which I am using inline with RhinoMocks is StructureMap.AutoMocking.  With StructureMap the main entry point is the ObjectFactory.  This will be process specific so if I decide that the I want a certain instance of a type to be used inside the ServiceLayer I cannot configure the ObjectFactory from my test class as that will only apply to the process which it belongs to. This is were I started thinking about two things: Running a WCF in process Being able to share mocked instances across processes A colleague in work pointed me to a project which is for the latter but I thought that it would be a better solution if I could run the WCF Service in process.  One of the projects which I use when I think about WCF Services is AGATHA, and the one which I have to used to try and get my head around doing this. Another asset I have is a book called Programming WCF Services by Juval Lowy and if you have not heard of it or read it I would definately recommend it.  One of the many topics that is inside this book is the type of configuration you need to communicate with a service in the same process, and it turns out to be quite simple from a config point of view. <system.serviceModel> <services> <service name="Agatha.ServiceLayer.WCF.WcfRequestProcessor"> <endpoint address ="net.pipe://localhost/MyPipe" binding="netNamedPipeBinding" contract="Agatha.Common.WCF.IWcfRequestProcessor"/> </service> </services> <client> <endpoint name="MyEndpoint" address="net.pipe://localhost/MyPipe" binding="netNamedPipeBinding" contract="Agatha.Common.WCF.IWcfRequestProcessor"/> </client> </system.serviceModel>   You can see here that I am referencing the Agatha object and contract here, but also that my binding and the address is something called Named Pipes.  THis is sort of the “Magic” which makes it happen in the same process. Next I need to open the service prior to calling the methods on a proxy which I also need.  My initial attempt at the proxy did not use any Agatha specific coding and one of the pains I found was that you obviously need to give your proxy the known types which the serializer can be aware of.  So we need to add to the known types of the proxy programmatically.  I came across the following blog post which showed me how easy it was http://bloggingabout.net/blogs/vagif/archive/2009/05/18/how-to-programmatically-define-known-types-in-wcf.aspx. First Pass So with this in mind, and inside a console app this was my first pass at consuming a service in process.  First here is the proxy which I made making use of the Agatha IWcfRequestProcessor contract. public class InProcProxy : ClientBase<Agatha.Common.WCF.IWcfRequestProcessor>, Agatha.Common.WCF.IWcfRequestProcessor { public InProcProxy() { } public InProcProxy(string configurationName) : base(configurationName) { } public Agatha.Common.Response[] Process(params Agatha.Common.Request[] requests) { return Channel.Process(requests); } public void ProcessOneWayRequests(params Agatha.Common.OneWayRequest[] requests) { Channel.ProcessOneWayRequests(requests); } } So with the proxy in place I could then use this after opening the service so here is the code which I use inside the console app make the request. static void Main(string[] args) { ComponentRegistration.Register(); ServiceHost serviceHost = new ServiceHost(typeof(Agatha.ServiceLayer.WCF.WcfRequestProcessor)); serviceHost.Open(); Console.WriteLine("Service is running...."); using (var proxy = new InProcProxy()) { foreach (var operation in proxy.Endpoint.Contract.Operations) { foreach (var t in KnownTypeProvider.GetKnownTypes(null)) { operation.KnownTypes.Add(t); } } var request = new GetProductsRequest(); var responses = proxy.Process(new[] { request }); var response = (GetProductsResponse)responses[0]; Console.WriteLine("{0} Products have been retrieved", response.Products.Count); } serviceHost.Close(); Console.WriteLine("Finished"); Console.ReadLine(); } So what I used here is the KnownTypeProvider of Agatha to easily get all the types I need for the service/proxy and add them to the proxy.  My Request handler for this was just a test one which always returned 2 products. public class GetProductsHandler : RequestHandler<GetProductsRequest,GetProductsResponse> { public override Agatha.Common.Response Handle(GetProductsRequest request) { return new GetProductsResponse { Products = new List<ProductDto> { new ProductDto{}, new ProductDto{} } }; } } Second Pass Now after I did this I started reading up some more on some resources including more by Davy Brion and others on Agatha.  Now it turns out that the work I did above to create a derived class of the ClientBase implementing Agatha.Common.WCF.IWcfRequestProcessor was not necessary due to a nice class which is present inside the Agatha code base, RequestProcessorProxy which takes care of this for you! :-) So disregarding that class I made for the proxy and changing my code to use it I am now left with the following: static void Main(string[] args) { ComponentRegistration.Register(); ServiceHost serviceHost = new ServiceHost(typeof(Agatha.ServiceLayer.WCF.WcfRequestProcessor)); serviceHost.Open(); Console.WriteLine("Service is running...."); using (var proxy = new RequestProcessorProxy()) { var request = new GetProductsRequest(); var responses = proxy.Process(new[] { request }); var response = (GetProductsResponse)responses[0]; Console.WriteLine("{0} Products have been retrieved", response.Products.Count); } serviceHost.Close(); Console.WriteLine("Finished"); Console.ReadLine(); }   Cheers for now, Andy References Agatha WCF InProcess Without WCF StructureMap.AutoMocking Cross Process Mocking Agatha Programming WCF Services by Juval Lowy

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  • Parallelism in .NET – Part 5, Partitioning of Work

    - by Reed
    When parallelizing any routine, we start by decomposing the problem.  Once the problem is understood, we need to break our work into separate tasks, so each task can be run on a different processing element.  This process is called partitioning. Partitioning our tasks is a challenging feat.  There are opposing forces at work here: too many partitions adds overhead, too few partitions leaves processors idle.  Trying to work the perfect balance between the two extremes is the goal for which we should aim.  Luckily, the Task Parallel Library automatically handles much of this process.  However, there are situations where the default partitioning may not be appropriate, and knowledge of our routines may allow us to guide the framework to making better decisions. First off, I’d like to say that this is a more advanced topic.  It is perfectly acceptable to use the parallel constructs in the framework without considering the partitioning taking place.  The default behavior in the Task Parallel Library is very well-behaved, even for unusual work loads, and should rarely be adjusted.  I have found few situations where the default partitioning behavior in the TPL is not as good or better than my own hand-written partitioning routines, and recommend using the defaults unless there is a strong, measured, and profiled reason to avoid using them.  However, understanding partitioning, and how the TPL partitions your data, helps in understanding the proper usage of the TPL. I indirectly mentioned partitioning while discussing aggregation.  Typically, our systems will have a limited number of Processing Elements (PE), which is the terminology used for hardware capable of processing a stream of instructions.  For example, in a standard Intel i7 system, there are four processor cores, each of which has two potential hardware threads due to Hyperthreading.  This gives us a total of 8 PEs – theoretically, we can have up to eight operations occurring concurrently within our system. In order to fully exploit this power, we need to partition our work into Tasks.  A task is a simple set of instructions that can be run on a PE.  Ideally, we want to have at least one task per PE in the system, since fewer tasks means that some of our processing power will be sitting idle.  A naive implementation would be to just take our data, and partition it with one element in our collection being treated as one task.  When we loop through our collection in parallel, using this approach, we’d just process one item at a time, then reuse that thread to process the next, etc.  There’s a flaw in this approach, however.  It will tend to be slower than necessary, often slower than processing the data serially. The problem is that there is overhead associated with each task.  When we take a simple foreach loop body and implement it using the TPL, we add overhead.  First, we change the body from a simple statement to a delegate, which must be invoked.  In order to invoke the delegate on a separate thread, the delegate gets added to the ThreadPool’s current work queue, and the ThreadPool must pull this off the queue, assign it to a free thread, then execute it.  If our collection had one million elements, the overhead of trying to spawn one million tasks would destroy our performance. The answer, here, is to partition our collection into groups, and have each group of elements treated as a single task.  By adding a partitioning step, we can break our total work into small enough tasks to keep our processors busy, but large enough tasks to avoid overburdening the ThreadPool.  There are two clear, opposing goals here: Always try to keep each processor working, but also try to keep the individual partitions as large as possible. When using Parallel.For, the partitioning is always handled automatically.  At first, partitioning here seems simple.  A naive implementation would merely split the total element count up by the number of PEs in the system, and assign a chunk of data to each processor.  Many hand-written partitioning schemes work in this exactly manner.  This perfectly balanced, static partitioning scheme works very well if the amount of work is constant for each element.  However, this is rarely the case.  Often, the length of time required to process an element grows as we progress through the collection, especially if we’re doing numerical computations.  In this case, the first PEs will finish early, and sit idle waiting on the last chunks to finish.  Sometimes, work can decrease as we progress, since previous computations may be used to speed up later computations.  In this situation, the first chunks will be working far longer than the last chunks.  In order to balance the workload, many implementations create many small chunks, and reuse threads.  This adds overhead, but does provide better load balancing, which in turn improves performance. The Task Parallel Library handles this more elaborately.  Chunks are determined at runtime, and start small.  They grow slowly over time, getting larger and larger.  This tends to lead to a near optimum load balancing, even in odd cases such as increasing or decreasing workloads.  Parallel.ForEach is a bit more complicated, however. When working with a generic IEnumerable<T>, the number of items required for processing is not known in advance, and must be discovered at runtime.  In addition, since we don’t have direct access to each element, the scheduler must enumerate the collection to process it.  Since IEnumerable<T> is not thread safe, it must lock on elements as it enumerates, create temporary collections for each chunk to process, and schedule this out.  By default, it uses a partitioning method similar to the one described above.  We can see this directly by looking at the Visual Partitioning sample shipped by the Task Parallel Library team, and available as part of the Samples for Parallel Programming.  When we run the sample, with four cores and the default, Load Balancing partitioning scheme, we see this: The colored bands represent each processing core.  You can see that, when we started (at the top), we begin with very small bands of color.  As the routine progresses through the Parallel.ForEach, the chunks get larger and larger (seen by larger and larger stripes). Most of the time, this is fantastic behavior, and most likely will out perform any custom written partitioning.  However, if your routine is not scaling well, it may be due to a failure in the default partitioning to handle your specific case.  With prior knowledge about your work, it may be possible to partition data more meaningfully than the default Partitioner. There is the option to use an overload of Parallel.ForEach which takes a Partitioner<T> instance.  The Partitioner<T> class is an abstract class which allows for both static and dynamic partitioning.  By overriding Partitioner<T>.SupportsDynamicPartitions, you can specify whether a dynamic approach is available.  If not, your custom Partitioner<T> subclass would override GetPartitions(int), which returns a list of IEnumerator<T> instances.  These are then used by the Parallel class to split work up amongst processors.  When dynamic partitioning is available, GetDynamicPartitions() is used, which returns an IEnumerable<T> for each partition.  If you do decide to implement your own Partitioner<T>, keep in mind the goals and tradeoffs of different partitioning strategies, and design appropriately. The Samples for Parallel Programming project includes a ChunkPartitioner class in the ParallelExtensionsExtras project.  This provides example code for implementing your own, custom allocation strategies, including a static allocator of a given chunk size.  Although implementing your own Partitioner<T> is possible, as I mentioned above, this is rarely required or useful in practice.  The default behavior of the TPL is very good, often better than any hand written partitioning strategy.

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  • Displaying an image on a LED matrix with a Netduino

    - by Bertrand Le Roy
    In the previous post, we’ve been flipping bits manually on three ports of the Netduino to simulate the data, clock and latch pins that a shift register expected. We did all that in order to control one line of a LED matrix and create a simple Knight Rider effect. It was rightly pointed out in the comments that the Netduino has built-in knowledge of the sort of serial protocol that this shift register understands through a feature called SPI. That will of course make our code a whole lot simpler, but it will also make it a whole lot faster: writing to the Netduino ports is actually not that fast, whereas SPI is very, very fast. Unfortunately, the Netduino documentation for SPI is severely lacking. Instead, we’ve been reliably using the documentation for the Fez, another .NET microcontroller. To send data through SPI, we’ll just need  to move a few wires around and update the code. SPI uses pin D11 for writing, pin D12 for reading (which we won’t do) and pin D13 for the clock. The latch pin is a parameter that can be set by the user. This is very close to the wiring we had before (data on D11, clock on D12 and latch on D13). We just have to move the latch from D13 to D10, and the clock from D12 to D13. The code that controls the shift register has slimmed down considerably with that change. Here is the new version, which I invite you to compare with what we had before: public class ShiftRegister74HC595 { protected SPI Spi; public ShiftRegister74HC595(Cpu.Pin latchPin) : this(latchPin, SPI.SPI_module.SPI1) { } public ShiftRegister74HC595(Cpu.Pin latchPin, SPI.SPI_module spiModule) { var spiConfig = new SPI.Configuration( SPI_mod: spiModule, ChipSelect_Port: latchPin, ChipSelect_ActiveState: false, ChipSelect_SetupTime: 0, ChipSelect_HoldTime: 0, Clock_IdleState: false, Clock_Edge: true, Clock_RateKHz: 1000 ); Spi = new SPI(spiConfig); } public void Write(byte buffer) { Spi.Write(new[] {buffer}); } } All we have to do here is configure SPI. The write method couldn’t be any simpler. Everything is now handled in hardware by the Netduino. We set the frequency to 1MHz, which is largely sufficient for what we’ll be doing, but it could potentially go much higher. The shift register addresses the columns of the matrix. The rows are directly wired to ports D0 to D7 of the Netduino. The code writes to only one of those eight lines at a time, which will make it fast enough. The way an image is displayed is that we light the lines one after the other so fast that persistence of vision will give the illusion of a stable image: foreach (var bitmap in matrix.MatrixBitmap) { matrix.OnRow(row, bitmap, true); matrix.OnRow(row, bitmap, false); row++; } Now there is a twist here: we need to run this code as fast as possible in order to display the image with as little flicker as possible, but we’ll eventually have other things to do. In other words, we need the code driving the display to run in the background, except when we want to change what’s being displayed. Fortunately, the .NET Micro Framework supports multithreading. In our implementation, we’ve added an Initialize method that spins a new thread that is tied to the specific instance of the matrix it’s being called on. public LedMatrix Initialize() { DisplayThread = new Thread(() => DoDisplay(this)); DisplayThread.Start(); return this; } I quite like this way to spin a thread. As you may know, there is another, built-in way to contextualize a thread by passing an object into the Start method. For the method to work, the thread must have been constructed with a ParameterizedThreadStart delegate, which takes one parameter of type object. I like to use object as little as possible, so instead I’m constructing a closure with a Lambda, currying it with the current instance. This way, everything remains strongly-typed and there’s no casting to do. Note that this method would extend perfectly to several parameters. Of note as well is the return value of Initialize, a common technique to add some fluency to the API and enabling the matrix to be instantiated and initialized in a single line: using (var matrix = new LedMS88SR74HC595().Initialize()) The “using” in the previous line is because we have implemented IDisposable so that the matrix kills the thread and clears the display when the user code is done with it: public void Dispose() { Clear(); DisplayThread.Abort(); } Thanks to the multi-threaded version of the matrix driver class, we can treat the display as a simple bitmap with a very synchronous programming model: matrix.Set(someimage); while (button.Read()) { Thread.Sleep(10); } Here, the call into Set returns immediately and from the moment the bitmap is set, the background display thread will constantly continue refreshing no matter what happens in the main thread. That enables us to wait or read a button’s port on the main thread knowing that the current image will continue displaying unperturbed and without requiring manual refreshing. We’ve effectively hidden the implementation of the display behind a convenient, synchronous-looking API. Pretty neat, eh? Before I wrap up this post, I want to talk about one small caveat of using SPI rather than driving the shift register directly: when we got to the point where we could actually display images, we noticed that they were a mirror image of what we were sending in. Oh noes! Well, the reason for it is that SPI is sending the bits in a big-endian fashion, in other words backwards. Now sure you could fix that in software by writing some bit-level code to reverse the bits we’re sending in, but there is a far more efficient solution than that. We are doing hardware here, so we can simply reverse the order in which the outputs of the shift register are connected to the columns of the matrix. That’s switching 8 wires around once, as compared to doing bit operations every time we send a line to display. All right, so bringing it all together, here is the code we need to write to display two images in succession, separated by a press on the board’s button: var button = new InputPort(Pins.ONBOARD_SW1, false, Port.ResistorMode.Disabled); using (var matrix = new LedMS88SR74HC595().Initialize()) { // Oh, prototype is so sad! var sad = new byte[] { 0x66, 0x24, 0x00, 0x18, 0x00, 0x3C, 0x42, 0x81 }; DisplayAndWait(sad, matrix, button); // Let's make it smile! var smile = new byte[] { 0x42, 0x18, 0x18, 0x81, 0x7E, 0x3C, 0x18, 0x00 }; DisplayAndWait(smile, matrix, button); } And here is a video of the prototype running: The prototype in action I’ve added an artificial delay between the display of each row of the matrix to clearly show what’s otherwise happening very fast. This way, you can clearly see each of the two images being displayed line by line. Next time, we’ll do no hardware changes, focusing instead on building a nice programming model for the matrix, with sprites, text and hardware scrolling. Fun stuff. By the way, can any of my reader guess where we’re going with all that? The code for this prototype can be downloaded here: http://weblogs.asp.net/blogs/bleroy/Samples/NetduinoLedMatrixDriver.zip

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  • Who IS Brian Solis?

    - by Michael Snow
    Q: Brian, Welcome to the WebCenter Blog. Can you tell our readers your current role and what career path brought you here? A: I’m proudly serving as a principal analyst at Altimeter Group, a research based advisory firm in Silicon Valley. My career path, well, let’s just say it’s a long and winding road. As a kid, I was fascinated with technology. I learned programming at an early age and found myself naturally drawn to all things tech. I started my career as a database programmer at a technology marketing agency in Southern California. When I saw the chance to work with tech companies and help them better market their capabilities to businesses and consumers, I switched focus from programming to marketing and advertising. As technologist, my approach to marketing was different. I didn’t believe in hype, fluff or buzz words. I believed in translating features into benefits and specifications and capabilities into solutions for real world problems and opportunities. In the mid 90’s I experimented with direct to consumer/customer engagement in dedicated technology forums and boards. I quickly realized that the entire approach to do so would need to change. Therefore, I learned and developed new methods for a more social and informed way of engaging people in ways that helped them, marketed the company, and also tied to tangible benefits for the company. This work would lead me to start an agency in 1999 dedicated to interactive marketing. As I continued to experiment with interactive platforms, I developed interesting methods for converting one-to-many forms of media into one-to-one-to-many programs. I ran that company until joining Altimeter Group. Along the way, in the early 2000s, I realized that everything was changing and that there were others like me finding success in what would become a more social form of media. I dedicated a significant amount of my time to sharing everything that I learned in the form of articles, blogs, and eventually books. My mission became to share my experience with anyone who’d listen. It would later become much bigger than marketing, this would lead to a decade of work, that still continues, in business transformation. Then and now, I find myself always assuming the role of a student. Q: As an industry analyst & technology change evangelist, what are you primarily focused on these days? A: As a digital analyst, I study how disruptive technology impacts business. As an aspiring social scientist, I study how technology affects human behavior. I explore both horizons professionally and personally to better understand the future of popular culture and also the opportunities that exist for organizations to improve relationships and experiences with customers and the people that are important to them. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? A: The line between work and life isn’t blurred it’s been overtly crossed and erased. We live in an always on society. The digital lifestyle keeps us connected to one another it keeps us connected all the time. Whether your sending or checking email, trying to catch up, or simply trying to get ahead, people are spending the equivalent of an extra day at work in the time they spend out of work…working. That’s absurd. It’s a matter of survival. It’s also a matter of unintended, subconscious self-causation. We brought this on ourselves and continue to do so. Think about your day. You’re in meetings for the better part of each day. You probably spend evenings and weekends catching up on email and actually doing the work you couldn’t get to during the day. And, your co-workers and executives are doing the same thing. So if you try to slow down, you find yourself at a disadvantage as you’re willfully pulling yourself out of an unfortunate culture of whenever wherever business dynamics. If you’re unresponsive or unreachable, someone within your organization or on your team is accessible. Over time, this could contribute to unfavorable impressions. I choose to steer my life balance in ways that complement one another. But, I don’t pretend to have this figured out by any means. In fact, I find myself swimming upstream like those around me. It’s essentially a competition for relevance and at some point I’ll learn how to earn attention and relevance while redrawing the line between work and life. Q: How can people keep up with what you’re working on? A: The easy answer is that people can keep up with me at briansolis.com. But, I also try to reach people where their attention is focused. Whether it’s Facebook (facebook.com/briansolis), Twitter (@briansolis), Google+ (+briansolis), Youtube (briansolis.tv) or through books and conferences, people can usually find me in a place of their choosing. Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon? A: I spent some time with the Oracle team reviewing the idea of Digital Darwinism and how technology and society are evolving faster than many organizations can adapt. Digital Darwinism: How Brands Can Survive the Rapid Evolution of Society and Technology Thursday, December 13, 2012, 10 a.m. PT / 1 p.m. ET Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast? A: We’re inviting guests to join us online as we dive into the future of business and how the convergence of technology and connected consumerism would ultimately impact how business is done. It’ll be an exciting and revealing conversation that explores just how much everything is changing. We’ll also review the importance of adapting to emergent trends and how to compete for the future. It’s important to recognize that change is not happening to us, it’s happening because of us. We are part of the revolution and therefore we need to help organizations adapt from the inside out. Watch the Entire Oracle Social Business Thought Leaders Webcast Series On-Demand and Stay Tuned for More to Come in 2013!

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  • Code Camp 2011 – Summary

    - by hajan
    Waiting whole twelve months to come this year’s Code Camp 2011 event was something which all Microsoft technologies (and even non-Microsoft techs.) developers were doing in the past year. Last year’s success was enough big to be heard and to influence everything around our developer community and beyond. Code Camp 2011 was nothing else but a invincible success which will remain in our memory for a long time from now. Darko Milevski (president of MKDOT.NET UG and SharePoint MVP) said something interesting at the event keynote that up to now we were looking at the past by saying what we did… now we will focus on the future and how to develop our community more and more in the future days, weeks, months and I hope so for many years… Even though it was held only two days ago (26th of November 2011), I already feel the nostalgia for everything that happened there and for the excellent time we have spent all together. ORGANIZED BY ENTHUSIASTS AND EXPERTS Code Camp 2011 was organized by number of community enthusiasts and experts who have unselfishly contributed with all their free time to make the best of this event. The event was organized by a known community group called MKDOT.NET User Group, name of a user group which is known not only in Macedonia, but also in many countries abroad. Organization mainly consists of software developers, technical leaders, team leaders in several known companies in Macedonia, as well as Microsoft MVPs. SPEAKERS There were 24 speakers at five parallel tracks. At Code Camp 2011 we had two groups of speakers: Professional Experts in various technologies and Student Speakers. The new interesting thing here is the Student Speakers, which draw attention a lot, especially to other students who were interested to see what their colleagues are going to speak about and how do they use Microsoft technologies in different coding scenarios and practices, in different topics. From the rest of the professional speakers, there were 7 Microsoft MVPs: Two ASP.NET/IIS MVPs, Two C# MVPs, and One MVP in SharePoint, SQL Server and Exchange Server. I must say that besides the MVP Speakers, who definitely did a great job as always… there were other excellent speakers as well, which were speaking on various technologies, such as: Web Development, Windows Phone Development, XNA, Windows 8, Games Development, Entity Framework, Event-driven programming, SOLID, SQLCLR, T-SQL, e.t.c. SESSIONS There were 25 sessions mainly all related to Microsoft technologies, but ranging from Windows 8, WP7, ASP.NET till Games Development, XNA and Event-driven programming. Sessions were going in five parallel tracks named as Red, Yellow, Green, Blue and Student track. Five presentations in each track, each with level 300 or 400. More info MY SESSION (ASP.NET MVC Best Practices) I must say that from the big number of speaking engagements I have had, this was one of my best performances and definitely I have set new records of attendees at my sessions and probably overall. I spoke on topic ASP.NET MVC Best Practices, where I have shown tips, tricks, guidelines and best practices on what to use and what to avoid by developing with one of the best web development frameworks nowadays, ASP.NET MVC. I had approximately 350+ attendees, the hall was full so that there was no room for staying at feet. Besides .NET developers, there were a lot of other technology oriented developers, who has also received the presentation very well and I really hope I gave them reason to think about ASP.NET as one of the best options for web development nowadays (if you ask me, it’s the best one ;-)). I have included 10 tips in using ASP.NET MVC each of them followed by a demo. Besides these 10 tips, I have briefly introduced the concept of ASP.NET MVC for those that haven’t been working with the framework and at the end some bonus tips. I must say there was lot of laugh for some funny sentences I have stated, like “If you code ASP.NET MVC, girls will love you more” – same goes for girls, only replace girls with boys :). [LINK TO SESSION WILL GO HERE, ONCE SESSIONS ARE AVAILABLE ON MK CODECAMP WEBSITE] VOLUNTEERS Without strong organization, such events wouldn’t be able to gather hundreds of attendees at one place and still stay perfectly organized to the smallest details, without dedicated organization and volunteers. I would like to dedicate this space in my blog to them and to say one big THANK YOU for supporting us before the event and during the whole day in the event. With such young and dedicated volunteers, we couldn’t achieve anything but great results. THANK YOU EVERYONE FOR YOUR CONTRIBUTION! NETWORKING One of the main reasons why we do such events is to gather all professionals in one place. Networking is what everyone wants because through this way of networking, we can meet incredible people in one place. It is amazing feeling to share your knowledge with others and exchange thoughts on various topics. Meet and talk to interesting people. I have had very special moments with many attendees especially after my presentation. Special Thank You to all of them who come to meet me in person, whether to ask a question, say congrats for my session or simply meet me and just smile :)… everything counts! Thank You! TWITTER During the event, twitter was one of the most useful event-wide communication tool where everyone could tweet with hash tag #mkcodecamp or #mkdotnet and say what he/she wants to say about the current state and happenings at that moment… In my next blog post I will list the top craziest tweets that were posted at this event… FUTURE OF MKDOT.NET Having such strong community around MKDOT.NET, the future seems very bright. The initial plans are to have sub-groups in several technologies, however all these sub-groups will belong to the MKDOT.NET UG which will be, somehow, the HEAD of these sub-groups. We are doing this to provide better divisions by technologies and organize ourselves better since our community is very big, around 500 members in MKDOT.NET.We will have five sub-groups:- Web User Group (Lead:Hajan Selmani - me)- Mobile User Group (Lead: Filip Kerazovski)- Visual C# User Group (Lead: Vekoslav Stefanovski)- SharePoint User Group (Lead: Darko Milevski)- Dynamics User Group (Lead: Vladimir Senih) SUMMARY Online registered attendees: ~1.200 Event attendees: ~800 Number of members in organization: 40+ Organized by: MKDOT.NET User Group Number of tracks: 5 Number of speakers: 24 Number of sessions: 25 Event official website: http://codecamp.mkdot.net Total number of sponsors: 20 Platinum Sponsors: Microsoft, INETA, Telerik Place held: FON University City and Country: Skopje, Macedonia THANK YOU FOR BEING PART OF THE BEST EVENT IN MACEDONIA, CODE CAMP 2011. Regards, Hajan

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  • A simple Dynamic Proxy

    - by Abhijeet Patel
    Frameworks such as EF4 and MOQ do what most developers consider "dark magic". For instance in EF4, when you use a POCO for an entity you can opt-in to get behaviors such as "lazy-loading" and "change tracking" at runtime merely by ensuring that your type has the following characteristics: The class must be public and not sealed. The class must have a public or protected parameter-less constructor. The class must have public or protected properties Adhere to this and your type is magically endowed with these behaviors without any additional programming on your part. Behind the scenes the framework subclasses your type at runtime and creates a "dynamic proxy" which has these additional behaviors and when you navigate properties of your POCO, the framework replaces the POCO type with derived type instances. The MOQ framework does simlar magic. Let's say you have a simple interface:   public interface IFoo      {          int GetNum();      }   We can verify that the GetNum() was invoked on a mock like so:   var mock = new Mock<IFoo>(MockBehavior.Default);   mock.Setup(f => f.GetNum());   var num = mock.Object.GetNum();   mock.Verify(f => f.GetNum());   Beind the scenes the MOQ framework is generating a dynamic proxy by implementing IFoo at runtime. the call to moq.Object returns the dynamic proxy on which we then call "GetNum" and then verify that this method was invoked. No dark magic at all, just clever programming is what's going on here, just not visible and hence appears magical! Let's create a simple dynamic proxy generator which accepts an interface type and dynamically creates a proxy implementing the interface type specified at runtime.     public static class DynamicProxyGenerator   {       public static T GetInstanceFor<T>()       {           Type typeOfT = typeof(T);           var methodInfos = typeOfT.GetMethods();           AssemblyName assName = new AssemblyName("testAssembly");           var assBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assName, AssemblyBuilderAccess.RunAndSave);           var moduleBuilder = assBuilder.DefineDynamicModule("testModule", "test.dll");           var typeBuilder = moduleBuilder.DefineType(typeOfT.Name + "Proxy", TypeAttributes.Public);              typeBuilder.AddInterfaceImplementation(typeOfT);           var ctorBuilder = typeBuilder.DefineConstructor(                     MethodAttributes.Public,                     CallingConventions.Standard,                     new Type[] { });           var ilGenerator = ctorBuilder.GetILGenerator();           ilGenerator.EmitWriteLine("Creating Proxy instance");           ilGenerator.Emit(OpCodes.Ret);           foreach (var methodInfo in methodInfos)           {               var methodBuilder = typeBuilder.DefineMethod(                   methodInfo.Name,                   MethodAttributes.Public | MethodAttributes.Virtual,                   methodInfo.ReturnType,                   methodInfo.GetParameters().Select(p => p.GetType()).ToArray()                   );               var methodILGen = methodBuilder.GetILGenerator();               methodILGen.EmitWriteLine("I'm a proxy");               if (methodInfo.ReturnType == typeof(void))               {                   methodILGen.Emit(OpCodes.Ret);               }               else               {                   if (methodInfo.ReturnType.IsValueType || methodInfo.ReturnType.IsEnum)                   {                       MethodInfo getMethod = typeof(Activator).GetMethod(/span>"CreateInstance",new Type[]{typeof((Type)});                                               LocalBuilder lb = methodILGen.DeclareLocal(methodInfo.ReturnType);                       methodILGen.Emit(OpCodes.Ldtoken, lb.LocalType);                       methodILGen.Emit(OpCodes.Call, typeofype).GetMethod("GetTypeFromHandle"));  ));                       methodILGen.Emit(OpCodes.Callvirt, getMethod);                       methodILGen.Emit(OpCodes.Unbox_Any, lb.LocalType);                                                              }                 else                   {                       methodILGen.Emit(OpCodes.Ldnull);                   }                   methodILGen.Emit(OpCodes.Ret);               }               typeBuilder.DefineMethodOverride(methodBuilder, methodInfo);           }                     Type constructedType = typeBuilder.CreateType();           var instance = Activator.CreateInstance(constructedType);           return (T)instance;       }   }   Dynamic proxies are created by calling into the following main types: AssemblyBuilder, TypeBuilder, Modulebuilder and ILGenerator. These types enable dynamically creating an assembly and emitting .NET modules and types in that assembly, all using IL instructions. Let's break down the code above a bit and examine it piece by piece                Type typeOfT = typeof(T);              var methodInfos = typeOfT.GetMethods();              AssemblyName assName = new AssemblyName("testAssembly");              var assBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assName, AssemblyBuilderAccess.RunAndSave);              var moduleBuilder = assBuilder.DefineDynamicModule("testModule", "test.dll");              var typeBuilder = moduleBuilder.DefineType(typeOfT.Name + "Proxy", TypeAttributes.Public);   We are instructing the runtime to create an assembly caled "test.dll"and in this assembly we then emit a new module called "testModule". We then emit a new type definition of name "typeName"Proxy into this new module. This is the definition for the "dynamic proxy" for type T                 typeBuilder.AddInterfaceImplementation(typeOfT);               var ctorBuilder = typeBuilder.DefineConstructor(                         MethodAttributes.Public,                         CallingConventions.Standard,                         new Type[] { });               var ilGenerator = ctorBuilder.GetILGenerator();               ilGenerator.EmitWriteLine("Creating Proxy instance");               ilGenerator.Emit(OpCodes.Ret);   The newly created type implements type T and defines a default parameterless constructor in which we emit a call to Console.WriteLine. This call is not necessary but we do this so that we can see first hand that when the proxy is constructed, when our default constructor is invoked.   var methodBuilder = typeBuilder.DefineMethod(                      methodInfo.Name,                      MethodAttributes.Public | MethodAttributes.Virtual,                      methodInfo.ReturnType,                      methodInfo.GetParameters().Select(p => p.GetType()).ToArray()                      );   We then iterate over each method declared on type T and add a method definition of the same name into our "dynamic proxy" definition     if (methodInfo.ReturnType == typeof(void))   {       methodILGen.Emit(OpCodes.Ret);   }   If the return type specified in the method declaration of T is void we simply return.     if (methodInfo.ReturnType.IsValueType || methodInfo.ReturnType.IsEnum)   {                               MethodInfo getMethod = typeof(Activator).GetMethod("CreateInstance",                                                         new Type[]{typeof(Type)});                               LocalBuilder lb = methodILGen.DeclareLocal(methodInfo.ReturnType);                                                     methodILGen.Emit(OpCodes.Ldtoken, lb.LocalType);       methodILGen.Emit(OpCodes.Call, typeof(Type).GetMethod("GetTypeFromHandle"));       methodILGen.Emit(OpCodes.Callvirt, getMethod);       methodILGen.Emit(OpCodes.Unbox_Any, lb.LocalType);   }   If the return type in the method declaration of T is either a value type or an enum, then we need to create an instance of the value type and return that instance the caller. In order to accomplish that we need to do the following: 1) Get a handle to the Activator.CreateInstance method 2) Declare a local variable which represents the Type of the return type(i.e the type object of the return type) specified on the method declaration of T(obtained from the MethodInfo) and push this Type object onto the evaluation stack. In reality a RuntimeTypeHandle is what is pushed onto the stack. 3) Invoke the "GetTypeFromHandle" method(a static method in the Type class) passing in the RuntimeTypeHandle pushed onto the stack previously as an argument, the result of this invocation is a Type object (representing the method's return type) which is pushed onto the top of the evaluation stack. 4) Invoke Activator.CreateInstance passing in the Type object from step 3, the result of this invocation is an instance of the value type boxed as a reference type and pushed onto the top of the evaluation stack. 5) Unbox the result and place it into the local variable of the return type defined in step 2   methodILGen.Emit(OpCodes.Ldnull);   If the return type is a reference type then we just load a null onto the evaluation stack   methodILGen.Emit(OpCodes.Ret);   Emit a a return statement to return whatever is on top of the evaluation stack(null or an instance of a value type) back to the caller     Type constructedType = typeBuilder.CreateType();   var instance = Activator.CreateInstance(constructedType);   return (T)instance;   Now that we have a definition of the "dynamic proxy" implementing all the methods declared on T, we can now create an instance of the proxy type and return that out typed as T. The caller can now invoke the generator and request a dynamic proxy for any type T. In our example when the client invokes GetNum() we get back "0". Lets add a new method on the interface called DayOfWeek GetDay()   public interface IFoo      {          int GetNum();          DayOfWeek GetDay();      }   When GetDay() is invoked, the "dynamic proxy" returns "Sunday" since that is the default value for the DayOfWeek enum This is a very trivial example of dynammic proxies, frameworks like MOQ have a way more sophisticated implementation of this paradigm where in you can instruct the framework to create proxies which return specified values for a method implementation.

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  • Scripting Language Sessions at Oracle OpenWorld and MySQL Connect, 2012

    - by cj
    This posts highlights some great scripting language sessions coming up at the Oracle OpenWorld and MySQL Connect conferences. These events are happening in San Francisco from the end of September. You can search for other interesting conference sessions in the Content Catalog. Also check out what is happening at JavaOne in that event's Content Catalog (I haven't included sessions from it in this post.) To find the timeslots and locations of each session, click their respective link and check the "Session Schedule" box on the top right. GEN8431 - General Session: What’s New in Oracle Database Application Development This general session takes a look at what’s been new in the last year in Oracle Database application development tools using the latest generation of database technology. Topics range from Oracle SQL Developer and Oracle Application Express to Java and PHP. (Thomas Kyte - Architect, Oracle) BOF9858 - Meet the Developers of Database Access Services (OCI, ODBC, DRCP, PHP, Python) This session is your opportunity to meet in person the Oracle developers who have built Oracle Database access tools and products such as the Oracle Call Interface (OCI), Oracle C++ Call Interface (OCCI), and Open Database Connectivity (ODBC) drivers; Transparent Application Failover (TAF); Oracle Database Instant Client; Database Resident Connection Pool (DRCP); Oracle Net Services, and so on. The team also works with those who develop the PHP, Ruby, Python, and Perl adapters for Oracle Database. Come discuss with them the features you like, your pains, and new product enhancements in the latest database technology. CON8506 - Syndication and Consolidation: Oracle Database Driver for MySQL Applications This technical session presents a new Oracle Database driver that enables you to run MySQL applications (written in PHP, Perl, C, C++, and so on) against Oracle Database with almost no code change. Use cases for such a driver include application syndication such as interoperability across a relationship database management system, application migration, and database consolidation. In addition, the session covers enhancements in database technology that enable and simplify the migration of third-party databases and applications to and consolidation with Oracle Database. Attend this session to learn more and see a live demo. (Srinath Krishnaswamy - Director, Software Development, Oracle. Kuassi Mensah - Director Product Management, Oracle. Mohammad Lari - Principal Technical Staff, Oracle ) CON9167 - Current State of PHP and MySQL Together, PHP and MySQL power large parts of the Web. The developers of both technologies continue to enhance their software to ensure that developers can be satisfied despite all their changing and growing needs. This session presents an overview of changes in PHP 5.4, which was released earlier this year and shows you various new MySQL-related features available for PHP, from transparent client-side caching to direct support for scaling and high-availability needs. (Johannes Schlüter - SoftwareDeveloper, Oracle) CON8983 - Sharding with PHP and MySQL In deploying MySQL, scale-out techniques can be used to scale out reads, but for scaling out writes, other techniques have to be used. To distribute writes over a cluster, it is necessary to shard the database and store the shards on separate servers. This session provides a brief introduction to traditional MySQL scale-out techniques in preparation for a discussion on the different sharding techniques that can be used with MySQL server and how they can be implemented with PHP. You will learn about static and dynamic sharding schemes, their advantages and drawbacks, techniques for locating and moving shards, and techniques for resharding. (Mats Kindahl - Senior Principal Software Developer, Oracle) CON9268 - Developing Python Applications with MySQL Utilities and MySQL Connector/Python This session discusses MySQL Connector/Python and the MySQL Utilities component of MySQL Workbench and explains how to write MySQL applications in Python. It includes in-depth explanations of the features of MySQL Connector/Python and the MySQL Utilities library, along with example code to illustrate the concepts. Those interested in learning how to expand or build their own utilities and connector features will benefit from the tips and tricks from the experts. This session also provides an opportunity to meet directly with the engineers and provide feedback on your issues and priorities. You can learn what exists today and influence future developments. (Geert Vanderkelen - Software Developer, Oracle) BOF9141 - MySQL Utilities and MySQL Connector/Python: Python Developers, Unite! Come to this lively discussion of the MySQL Utilities component of MySQL Workbench and MySQL Connector/Python. It includes in-depth explanations of the features and dives into the code for those interested in learning how to expand or build their own utilities and connector features. This is an audience-driven session, so put on your best Python shirt and let’s talk about MySQL Utilities and MySQL Connector/Python. (Geert Vanderkelen - Software Developer, Oracle. Charles Bell - Senior Software Developer, Oracle) CON3290 - Integrating Oracle Database with a Social Network Facebook, Flickr, YouTube, Google Maps. There are many social network sites, each with their own APIs for sharing data with them. Most developers do not realize that Oracle Database has base tools for communicating with these sites, enabling all manner of information, including multimedia, to be passed back and forth between the sites. This technical presentation goes through the methods in PL/SQL for connecting to, and then sending and retrieving, all types of data between these sites. (Marcelle Kratochvil - CTO, Piction) CON3291 - Storing and Tuning Unstructured Data and Multimedia in Oracle Database Database administrators need to learn new skills and techniques when the decision is made in their organization to let Oracle Database manage its unstructured data. They will face new scalability challenges. A single row in a table can become larger than a whole database. This presentation covers the techniques a DBA needs for managing the large volume of data in a standard Oracle Database instance. (Marcelle Kratochvil - CTO, Piction) CON3292 - Using PHP, Perl, Visual Basic, Ruby, and Python for Multimedia in Oracle Database These five programming languages are just some of the most popular ones in use at the moment in the marketplace. This presentation details how you can use them to access and retrieve multimedia from Oracle Database. It covers programming techniques and methods for achieving faster development against Oracle Database. (Marcelle Kratochvil - CTO, Piction) UGF5181 - Building Real-World Oracle DBA Tools in Perl Perl is not normally associated with building mission-critical application or DBA tools. Learn why Perl could be a good choice for building your next killer DBA app. This session draws on real-world experience of building DBA tools in Perl, showing the framework and architecture needed to deal with portability, efficiency, and maintainability. Topics include Perl frameworks; Which Comprehensive Perl Archive Network (CPAN) modules are good to use; Perl and CPAN module licensing; Perl and Oracle connectivity; Compiling and deploying your app; An example of what is possible with Perl. (Arjen Visser - CEO & CTO, Dbvisit Software Limited) CON3153 - Perl: A DBA’s and Developer’s Best (Forgotten) Friend This session reintroduces Perl as a language of choice for many solutions for DBAs and developers. Discover what makes Perl so successful and why it is so versatile in our day-to-day lives. Perl can automate all those manual tasks and is truly platform-independent. Perl may not be in the limelight the way other languages are, but it is a remarkable language, it is still very current with ongoing development, and it has amazing online resources. Learn what makes Perl so great (including CPAN), get an introduction to Perl language syntax, find out what you can use Perl for, hear how Oracle uses Perl, discover the best way to learn Perl, and take away a small Perl project challenge. (Arjen Visser - CEO & CTO, Dbvisit Software Limited) CON10332 - Oracle RightNow CX Cloud Service’s Connect PHP API: Intro, What’s New, and Roadmap Connect PHP is a public API that enables developers to build solutions with the Oracle RightNow CX Cloud Service platform. This API is used primarily by developers working within the Oracle RightNow Customer Portal Cloud Service framework who are looking to gain access to data and services hosted by the Oracle RightNow CX Cloud Service platform through a backward-compatible API. Connect for PHP leverages the same data model and services as the Connect Web Services for SOAP API. Come to this session to get an introduction and learn what’s new and what’s coming up. (Mark Rhoads - Senior Principal Applications Engineer, Oracle. Mark Ericson - Sr. Principle Product Manager, Oracle) CON10330 - Oracle RightNow CX Cloud Service APIs and Frameworks Overview Oracle RightNow CX Cloud Service APIs are available in the following areas: desktop UI, Web services, customer portal, PHP, and knowledge. These frameworks provide access to Oracle RightNow CX Cloud Service’s Connect Common Object Model and custom objects. This session provides a broad overview of capabilities in all these areas. (Mark Ericson - Sr. Principle Product Manager, Oracle)

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  • Personal Development : Time, Planning , Repairs & Maintenance

    - by Rajesh Pillai
    Personal Development : Time, Planning, Repairs & Maintenance These are just my thoughts, but some you may find something interesting in it. Please think over it. We may know many things, but still we always keeps procrastinating it. I have written this as I have heard many people coming back and saying they don’t have time to do things they like. These are my thoughts buy may be useful to someone else too. Certain things in life needs periodic repairs and maintenance. To cite some examples , your CAR, your HOUSE, your personal laptop/desktop, your health etc. Likewise there are certain other things in professional life that requires repair/ maintenance /or some kind of polishing, so that you always stay on top of it. But they are not always obvious. Some of them are - Improving your communication skills - Increasing your vocabulary - Upgrading your technical skills - Pursuing your hobby - Increasing your knowledge/awareness etc… etc… And then there are certain things that we are always short of…. one is TIME. We all know TIME is one of the most precious things in life and yet we all are very miserable at managing it. Remember you can only manage it and not control it. You can only control which you own or which you create. In theory time is infinite. So, there should be abundant of it. But remember one thing, you know this, it’s not reversible. Once it has elapsed you cannot live it again. Think over it. So, how do find that golden 25th hour every day. To find the 25th hour you need to reflect back on your current daily activities. Analyze them and see where you are spending most of your time and is it really important. Even the 8 hours that you spent in the office, is it spent fruitfully. At the end of the day is the 8 precious hour that you spent was worth it. Just reflect back on your activities. Did you learn something? If yes did you make a point to NOTE IT. If you didn’t NOTED it then was the time you spent really worth it. Just ponder over it. Some calculations of your daily activities where most of the time is spent. Let’s start (in no particular order though) - Sleep (6.5 hours) [Remember you only require 6 good hours of sleep every day]. Some may thing it is 8, but it’s a myth.   o To achive 6 hours of sleep and be in good health you can practice 15 minutes of daily meditation. So effectively you can    round it to 6.5 hours. - Morning chores(2 hours) : Some may need to prepare breakfast and all other things. - Office commuting (avg. to and fro 3 hours) - Office Work (avg 9.5 hours) Total Hours: 21 hours effective time which is spent irrespective of what you do. There may be some variations here and there. Still you have 3 hours EXTRA. Where do these 3 hours go? If you can find it, then you may get that golden 25th hour out of these 3 hours. Let’s discount 2 hours for contingencies, still you have 1 hour with you. If you can’t find it then you are living a direction less life. As you can see, the 25th Hour lies within the 24 hours of the day. It’s upto each one of us to find and make use of it. Now what can you do with that 25th hour i.e. 1 hour extra of your life. Imagine the possibility. Again some calculations 1 hour daily * 30 days = 30 hours every month 30 hours pm * 12 month = 360 hours every year. 360 hours every year seems very promising. Let’s add some contingencies, say, let’s be optimistic and say 50 % contingency. Still you have 180 hours every year. That leaves with 30 minutes every day of extra time. That’s hell a lot of time, if you could manage it. These may sound like a high talk [yes, it is, unless you apply these simple rules and rationalize your everyday living and stop procrastinating]. NOTE: I haven’t taken weekend, holidays and leaves into account. So, that leaves us with a lot of buffer time. You can meet family friends, relatives, other tasks, and yet have these 180 pure hours of joy every year. Do whatever you want to do with it. So, how important is this 180 hours per year to you? Just think over it. You may use it the way you like - 50 hours [pursue your hobby like drawing, crafting, learn dance, learn juggling, learn swimming, travelling hmm.. anything you like doing and you didn’t had time to do it.] - 30 hours you can learn a new programming language or technology (i.e. you can get comfortable with it) - 50 hours [improve existing skills] - 20 hours [improve you communication skill]. Do some light reading. - 30 hours [YOU DECIDE WHAT TO DO]? So, if you had done this for one year you would have learnt a new programming language, upgraded existing skills, improved you communication etc.. If you had done this for two years.. imagine the level of personal development or growth which you may have attained….. If you had done this for three years….. NOW I think I don’t need to mention this… So, you still have TIME, as they say TIME is infinite. So, make judicious use of this precious thing. And never ever comeback saying “I don’t have time”. So, if you are RICH in TIME, everything else will be automatically taken care of, as those things may just be a byproduct of how you spend your time… So, happy TIMING your TIME everyday.

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  • C# Performance Pitfall – Interop Scenarios Change the Rules

    - by Reed
    C# and .NET, overall, really do have fantastic performance in my opinion.  That being said, the performance characteristics dramatically differ from native programming, and take some relearning if you’re used to doing performance optimization in most other languages, especially C, C++, and similar.  However, there are times when revisiting tricks learned in native code play a critical role in performance optimization in C#. I recently ran across a nasty scenario that illustrated to me how dangerous following any fixed rules for optimization can be… The rules in C# when optimizing code are very different than C or C++.  Often, they’re exactly backwards.  For example, in C and C++, lifting a variable out of loops in order to avoid memory allocations often can have huge advantages.  If some function within a call graph is allocating memory dynamically, and that gets called in a loop, it can dramatically slow down a routine. This can be a tricky bottleneck to track down, even with a profiler.  Looking at the memory allocation graph is usually the key for spotting this routine, as it’s often “hidden” deep in call graph.  For example, while optimizing some of my scientific routines, I ran into a situation where I had a loop similar to: for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i]); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This loop was at a fairly high level in the call graph, and often could take many hours to complete, depending on the input data.  As such, any performance optimization we could achieve would be greatly appreciated by our users. After a fair bit of profiling, I noticed that a couple of function calls down the call graph (inside of ProcessElement), there was some code that effectively was doing: // Allocate some data required DataStructure* data = new DataStructure(num); // Call into a subroutine that passed around and manipulated this data highly CallSubroutine(data); // Read and use some values from here double values = data->Foo; // Cleanup delete data; // ... return bar; Normally, if “DataStructure” was a simple data type, I could just allocate it on the stack.  However, it’s constructor, internally, allocated it’s own memory using new, so this wouldn’t eliminate the problem.  In this case, however, I could change the call signatures to allow the pointer to the data structure to be passed into ProcessElement and through the call graph, allowing the inner routine to reuse the same “data” memory instead of allocating.  At the highest level, my code effectively changed to something like: DataStructure* data = new DataStructure(numberToProcess); for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i], data); } delete data; Granted, this dramatically reduced the maintainability of the code, so it wasn’t something I wanted to do unless there was a significant benefit.  In this case, after profiling the new version, I found that it increased the overall performance dramatically – my main test case went from 35 minutes runtime down to 21 minutes.  This was such a significant improvement, I felt it was worth the reduction in maintainability. In C and C++, it’s generally a good idea (for performance) to: Reduce the number of memory allocations as much as possible, Use fewer, larger memory allocations instead of many smaller ones, and Allocate as high up the call stack as possible, and reuse memory I’ve seen many people try to make similar optimizations in C# code.  For good or bad, this is typically not a good idea.  The garbage collector in .NET completely changes the rules here. In C#, reallocating memory in a loop is not always a bad idea.  In this scenario, for example, I may have been much better off leaving the original code alone.  The reason for this is the garbage collector.  The GC in .NET is incredibly effective, and leaving the allocation deep inside the call stack has some huge advantages.  First and foremost, it tends to make the code more maintainable – passing around object references tends to couple the methods together more than necessary, and overall increase the complexity of the code.  This is something that should be avoided unless there is a significant reason.  Second, (unlike C and C++) memory allocation of a single object in C# is normally cheap and fast.  Finally, and most critically, there is a large advantage to having short lived objects.  If you lift a variable out of the loop and reuse the memory, its much more likely that object will get promoted to Gen1 (or worse, Gen2).  This can cause expensive compaction operations to be required, and also lead to (at least temporary) memory fragmentation as well as more costly collections later. As such, I’ve found that it’s often (though not always) faster to leave memory allocations where you’d naturally place them – deep inside of the call graph, inside of the loops.  This causes the objects to stay very short lived, which in turn increases the efficiency of the garbage collector, and can dramatically improve the overall performance of the routine as a whole. In C#, I tend to: Keep variable declarations in the tightest scope possible Declare and allocate objects at usage While this tends to cause some of the same goals (reducing unnecessary allocations, etc), the goal here is a bit different – it’s about keeping the objects rooted for as little time as possible in order to (attempt) to keep them completely in Gen0, or worst case, Gen1.  It also has the huge advantage of keeping the code very maintainable – objects are used and “released” as soon as possible, which keeps the code very clean.  It does, however, often have the side effect of causing more allocations to occur, but keeping the objects rooted for a much shorter time. Now – nowhere here am I suggesting that these rules are hard, fast rules that are always true.  That being said, my time spent optimizing over the years encourages me to naturally write code that follows the above guidelines, then profile and adjust as necessary.  In my current project, however, I ran across one of those nasty little pitfalls that’s something to keep in mind – interop changes the rules. In this case, I was dealing with an API that, internally, used some COM objects.  In this case, these COM objects were leading to native allocations (most likely C++) occurring in a loop deep in my call graph.  Even though I was writing nice, clean managed code, the normal managed code rules for performance no longer apply.  After profiling to find the bottleneck in my code, I realized that my inner loop, a innocuous looking block of C# code, was effectively causing a set of native memory allocations in every iteration.  This required going back to a “native programming” mindset for optimization.  Lifting these variables and reusing them took a 1:10 routine down to 0:20 – again, a very worthwhile improvement. Overall, the lessons here are: Always profile if you suspect a performance problem – don’t assume any rule is correct, or any code is efficient just because it looks like it should be Remember to check memory allocations when profiling, not just CPU cycles Interop scenarios often cause managed code to act very differently than “normal” managed code. Native code can be hidden very cleverly inside of managed wrappers

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  • Fraud Detection with the SQL Server Suite Part 2

    - by Dejan Sarka
    This is the second part of the fraud detection whitepaper. You can find the first part in my previous blog post about this topic. My Approach to Data Mining Projects It is impossible to evaluate the time and money needed for a complete fraud detection infrastructure in advance. Personally, I do not know the customer’s data in advance. I don’t know whether there is already an existing infrastructure, like a data warehouse, in place, or whether we would need to build one from scratch. Therefore, I always suggest to start with a proof-of-concept (POC) project. A POC takes something between 5 and 10 working days, and involves personnel from the customer’s site – either employees or outsourced consultants. The team should include a subject matter expert (SME) and at least one information technology (IT) expert. The SME must be familiar with both the domain in question as well as the meaning of data at hand, while the IT expert should be familiar with the structure of data, how to access it, and have some programming (preferably Transact-SQL) knowledge. With more than one IT expert the most time consuming work, namely data preparation and overview, can be completed sooner. I assume that the relevant data is already extracted and available at the very beginning of the POC project. If a customer wants to have their people involved in the project directly and requests the transfer of knowledge, the project begins with training. I strongly advise this approach as it offers the establishment of a common background for all people involved, the understanding of how the algorithms work and the understanding of how the results should be interpreted, a way of becoming familiar with the SQL Server suite, and more. Once the data has been extracted, the customer’s SME (i.e. the analyst), and the IT expert assigned to the project will learn how to prepare the data in an efficient manner. Together with me, knowledge and expertise allow us to focus immediately on the most interesting attributes and identify any additional, calculated, ones soon after. By employing our programming knowledge, we can, for example, prepare tens of derived variables, detect outliers, identify the relationships between pairs of input variables, and more, in only two or three days, depending on the quantity and the quality of input data. I favor the customer’s decision of assigning additional personnel to the project. For example, I actually prefer to work with two teams simultaneously. I demonstrate and explain the subject matter by applying techniques directly on the data managed by each team, and then both teams continue to work on the data overview and data preparation under our supervision. I explain to the teams what kind of results we expect, the reasons why they are needed, and how to achieve them. Afterwards we review and explain the results, and continue with new instructions, until we resolve all known problems. Simultaneously with the data preparation the data overview is performed. The logic behind this task is the same – again I show to the teams involved the expected results, how to achieve them and what they mean. This is also done in multiple cycles as is the case with data preparation, because, quite frankly, both tasks are completely interleaved. A specific objective of the data overview is of principal importance – it is represented by a simple star schema and a simple OLAP cube that will first of all simplify data discovery and interpretation of the results, and will also prove useful in the following tasks. The presence of the customer’s SME is the key to resolving possible issues with the actual meaning of the data. We can always replace the IT part of the team with another database developer; however, we cannot conduct this kind of a project without the customer’s SME. After the data preparation and when the data overview is available, we begin the scientific part of the project. I assist the team in developing a variety of models, and in interpreting the results. The results are presented graphically, in an intuitive way. While it is possible to interpret the results on the fly, a much more appropriate alternative is possible if the initial training was also performed, because it allows the customer’s personnel to interpret the results by themselves, with only some guidance from me. The models are evaluated immediately by using several different techniques. One of the techniques includes evaluation over time, where we use an OLAP cube. After evaluating the models, we select the most appropriate model to be deployed for a production test; this allows the team to understand the deployment process. There are many possibilities of deploying data mining models into production; at the POC stage, we select the one that can be completed quickly. Typically, this means that we add the mining model as an additional dimension to an existing DW or OLAP cube, or to the OLAP cube developed during the data overview phase. Finally, we spend some time presenting the results of the POC project to the stakeholders and managers. Even from a POC, the customer will receive lots of benefits, all at the sole risk of spending money and time for a single 5 to 10 day project: The customer learns the basic patterns of frauds and fraud detection The customer learns how to do the entire cycle with their own people, only relying on me for the most complex problems The customer’s analysts learn how to perform much more in-depth analyses than they ever thought possible The customer’s IT experts learn how to perform data extraction and preparation much more efficiently than they did before All of the attendees of this training learn how to use their own creativity to implement further improvements of the process and procedures, even after the solution has been deployed to production The POC output for a smaller company or for a subsidiary of a larger company can actually be considered a finished, production-ready solution It is possible to utilize the results of the POC project at subsidiary level, as a finished POC project for the entire enterprise Typically, the project results in several important “side effects” Improved data quality Improved employee job satisfaction, as they are able to proactively contribute to the central knowledge about fraud patterns in the organization Because eventually more minds get to be involved in the enterprise, the company should expect more and better fraud detection patterns After the POC project is completed as described above, the actual project would not need months of engagement from my side. This is possible due to our preference to transfer the knowledge onto the customer’s employees: typically, the customer will use the results of the POC project for some time, and only engage me again to complete the project, or to ask for additional expertise if the complexity of the problem increases significantly. I usually expect to perform the following tasks: Establish the final infrastructure to measure the efficiency of the deployed models Deploy the models in additional scenarios Through reports By including Data Mining Extensions (DMX) queries in OLTP applications to support real-time early warnings Include data mining models as dimensions in OLAP cubes, if this was not done already during the POC project Create smart ETL applications that divert suspicious data for immediate or later inspection I would also offer to investigate how the outcome could be transferred automatically to the central system; for instance, if the POC project was performed in a subsidiary whereas a central system is available as well Of course, for the actual project, I would repeat the data and model preparation as needed It is virtually impossible to tell in advance how much time the deployment would take, before we decide together with customer what exactly the deployment process should cover. Without considering the deployment part, and with the POC project conducted as suggested above (including the transfer of knowledge), the actual project should still only take additional 5 to 10 days. The approximate timeline for the POC project is, as follows: 1-2 days of training 2-3 days for data preparation and data overview 2 days for creating and evaluating the models 1 day for initial preparation of the continuous learning infrastructure 1 day for presentation of the results and discussion of further actions Quite frequently I receive the following question: are we going to find the best possible model during the POC project, or during the actual project? My answer is always quite simple: I do not know. Maybe, if we would spend just one hour more for data preparation, or create just one more model, we could get better patterns and predictions. However, we simply must stop somewhere, and the best possible way to do this, according to my experience, is to restrict the time spent on the project in advance, after an agreement with the customer. You must also never forget that, because we build the complete learning infrastructure and transfer the knowledge, the customer will be capable of doing further investigations independently and improve the models and predictions over time without the need for a constant engagement with me.

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  • PostSharp, Obfuscation, and IL

    - by Simon Cooper
    Aspect-oriented programming (AOP) is a relatively new programming paradigm. Originating at Xerox PARC in 1994, the paradigm was first made available for general-purpose development as an extension to Java in 2001. From there, it has quickly been adapted for use in all the common languages used today. In the .NET world, one of the primary AOP toolkits is PostSharp. Attributes and AOP Normally, attributes in .NET are entirely a metadata construct. Apart from a few special attributes in the .NET framework, they have no effect whatsoever on how a class or method executes within the CLR. Only by using reflection at runtime can you access any attributes declared on a type or type member. PostSharp changes this. By declaring a custom attribute that derives from PostSharp.Aspects.Aspect, applying it to types and type members, and running the resulting assembly through the PostSharp postprocessor, you can essentially declare 'clever' attributes that change the behaviour of whatever the aspect has been applied to at runtime. A simple example of this is logging. By declaring a TraceAttribute that derives from OnMethodBoundaryAspect, you can automatically log when a method has been executed: public class TraceAttribute : PostSharp.Aspects.OnMethodBoundaryAspect { public override void OnEntry(MethodExecutionArgs args) { MethodBase method = args.Method; System.Diagnostics.Trace.WriteLine( String.Format( "Entering {0}.{1}.", method.DeclaringType.FullName, method.Name)); } public override void OnExit(MethodExecutionArgs args) { MethodBase method = args.Method; System.Diagnostics.Trace.WriteLine( String.Format( "Leaving {0}.{1}.", method.DeclaringType.FullName, method.Name)); } } [Trace] public void MethodToLog() { ... } Now, whenever MethodToLog is executed, the aspect will automatically log entry and exit, without having to add the logging code to MethodToLog itself. PostSharp Performance Now this does introduce a performance overhead - as you can see, the aspect allows access to the MethodBase of the method the aspect has been applied to. If you were limited to C#, you would be forced to retrieve each MethodBase instance using Type.GetMethod(), matching on the method name and signature. This is slow. Fortunately, PostSharp is not limited to C#. It can use any instruction available in IL. And in IL, you can do some very neat things. Ldtoken C# allows you to get the Type object corresponding to a specific type name using the typeof operator: Type t = typeof(Random); The C# compiler compiles this operator to the following IL: ldtoken [mscorlib]System.Random call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle( valuetype [mscorlib]System.RuntimeTypeHandle) The ldtoken instruction obtains a special handle to a type called a RuntimeTypeHandle, and from that, the Type object can be obtained using GetTypeFromHandle. These are both relatively fast operations - no string lookup is required, only direct assembly and CLR constructs are used. However, a little-known feature is that ldtoken is not just limited to types; it can also get information on methods and fields, encapsulated in a RuntimeMethodHandle or RuntimeFieldHandle: // get a MethodBase for String.EndsWith(string) ldtoken method instance bool [mscorlib]System.String::EndsWith(string) call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle( valuetype [mscorlib]System.RuntimeMethodHandle) // get a FieldInfo for the String.Empty field ldtoken field string [mscorlib]System.String::Empty call class [mscorlib]System.Reflection.FieldInfo [mscorlib]System.Reflection.FieldInfo::GetFieldFromHandle( valuetype [mscorlib]System.RuntimeFieldHandle) These usages of ldtoken aren't usable from C# or VB, and aren't likely to be added anytime soon (Eric Lippert's done a blog post on the possibility of adding infoof, methodof or fieldof operators to C#). However, PostSharp deals directly with IL, and so can use ldtoken to get MethodBase objects quickly and cheaply, without having to resort to string lookups. The kicker However, there are problems. Because ldtoken for methods or fields isn't accessible from C# or VB, it hasn't been as well-tested as ldtoken for types. This has resulted in various obscure bugs in most versions of the CLR when dealing with ldtoken and methods, and specifically, generic methods and methods of generic types. This means that PostSharp was behaving incorrectly, or just plain crashing, when aspects were applied to methods that were generic in some way. So, PostSharp has to work around this. Without using the metadata tokens directly, the only way to get the MethodBase of generic methods is to use reflection: Type.GetMethod(), passing in the method name as a string along with information on the signature. Now, this works fine. It's slower than using ldtoken directly, but it works, and this only has to be done for generic methods. Unfortunately, this poses problems when the assembly is obfuscated. PostSharp and Obfuscation When using ldtoken, obfuscators don't affect how PostSharp operates. Because the ldtoken instruction directly references the type, method or field within the assembly, it is unaffected if the name of the object is changed by an obfuscator. However, the indirect loading used for generic methods was breaking, because that uses the name of the method when the assembly is put through the PostSharp postprocessor to lookup the MethodBase at runtime. If the name then changes, PostSharp can't find it anymore, and the assembly breaks. So, PostSharp needs to know about any changes an obfuscator does to an assembly. The way PostSharp does this is by adding another layer of indirection. When PostSharp obfuscation support is enabled, it includes an extra 'name table' resource in the assembly, consisting of a series of method & type names. When PostSharp needs to lookup a method using reflection, instead of encoding the method name directly, it looks up the method name at a fixed offset inside that name table: MethodBase genericMethod = typeof(ContainingClass).GetMethod(GetNameAtIndex(22)); PostSharp.NameTable resource: ... 20: get_Prop1 21: set_Prop1 22: DoFoo 23: GetWibble When the assembly is later processed by an obfuscator, the obfuscator can replace all the method and type names within the name table with their new name. That way, the reflection lookups performed by PostSharp will now use the new names, and everything will work as expected: MethodBase genericMethod = typeof(#kGy).GetMethod(GetNameAtIndex(22)); PostSharp.NameTable resource: ... 20: #kkA 21: #zAb 22: #EF5a 23: #2tg As you can see, this requires direct support by an obfuscator in order to perform these rewrites. Dotfuscator supports it, and now, starting with SmartAssembly 6.6.4, SmartAssembly does too. So, a relatively simple solution to a tricky problem, with some CLR bugs thrown in for good measure. You don't see those every day!

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