problem - Page 590 - Developer IT

How does one find out which application is associated with an indicator icon?

- by Amos Annoy

It is trivial to do this in Ubuntu 10.04. The question is specific to Ubuntu 12.04. some pertinent references (src: answer to What is the difference between indicators and a system tray?: Here is the documentation for indicators: Application indicators | Ubuntu App Developer libindicate Reference Manual libappindicator Reference Manual also DesktopExperienceTeam/ApplicationIndicators - Ubuntu Wiki ref: How can the application that makes an indicator icon be identified? bookmark: How does one find out which application is associated with an indicator icon in Ubuntu 12.04? is a serious question for reasons & problems outlined below and for which a significant investment has been made and is necessary for remedial purposes. reviewing refs. to find an orchestrated resolution ... (an indicator ap. indicator maybe needed) This has nothing to do (does it?) with right click. How can an indicator's icon in Ubuntu 12.04 be matched with the program responsible for it's manifestation on the top panel? A list of running applications can include all processes using System Monitor. How is the correct matching process found for an indicator? How are the sub-indicator applications identified? These are the aps associated with the components of an indicators drop-down menu. (This was to be a separate question and quite naturally follows up the progression. It is included here as it is obvious there is no provisioning to track down offending either sub or indicator aps. easily.) (The examination of SM points out a rather poignant factor in the faster battery depletion and shortened run time - the ambient quiescent CPU rate in 12.04 is now well over 20% when previously, in 10.04, it was well under 10%, between 5% and 7%! - the huge inordinate cpu overhead originates from Xorg and compiz - after booting the system, only SM is run and All Processes are selected, sorting on %CPU - switching between Resources and Processes profiles the execution overhead problem - running another ap like gedit "Text Editor" briefly gives it CPU priority - going back to S&M several aps. are at the top of the list in order: gnome-system-monitor as expected, then: Xorg, compiz, unity-panel-service, hud-service, with dbus-daemon and kworker/x:y's mixed in with some expected daemons and background tasks like nm-applet - not only do Xorg and compiz require excessive CPU time but their entourage has to come along too! further exacerbating the problem - our compute bound tasks no longer work effectively in the field - reduced battery life, reduced CPU time for custom ap.s etc. - and all this precipitated from an examination of what is going on with the battery ap. indicator - this was and is not a flippant, rhetorical or idle musing but has consequences for the credible deployment of 12.04 to reduce the negative impact of its overhead in a production environment) (I have a problem with the battery indicator - it sometimes has % and other times hh:mm - it is necessary to know the ap. & v. to get more info on controlling same. ditto: There are issues with other indicator aps.: NM vs. iwlist/iwconfig conflict, BT ap. vs RF switch, Battery ap. w/ no suspend/sleep for poor battery runtime, ... the list goes on) Details from: How can I find Application Indicator ID's? suggests looking at: file:///usr/share/indicator-application/ordering-override.keyfile [Ordering Index Overrides] nm-applet=1 gnome-power-manager=2 ibus=3 gst-keyboard-xkb=4 gsd-keyboard-xkb=5 which solves the battery ap. identification, and presumably nm is NetworkManager for the rf icon, but the envelope, blue tooth and speaker indicator aps. are still a mystery. (Also, the ordering is not correlated.) Mind you, it was simple in the past to simply right click to get the About option to find the ap. & v. info. browsing around and about: file:///usr/share/indicator-application/ordering-override.keyfile examined: file:///usr/share/indicators file:///usr/share/indicators/messages/applications/ ... perhaps?/presumably? the information sought may be buried in file:///usr/share/indicators A reference in the comments was given to: What is the difference between indicators and a system tray? quoting from that source ... Unfortunately desktop indicators are not well documented yet: I couldn't find any specification doc ... Well ... the actual document https://wiki.ubuntu.com/DesktopExperienceTeam/ApplicationIndicators#Summary does not help much but it's existential information provides considerable insight ...

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How do I prove or disprove "god" objects are wrong?

- by honestduane

Problem Summary: Long story short, I inherited a code base and an development team I am not allowed to replace and the use of God Objects is a big issue. Going forward, I want to have us re-factor things but I am getting push-back from the teams who want to do everything with God Objects "because its easier" and this means I would not be allowed to re-factor. I pushed back citing my years of dev experience, that I'm the new boss who was hired to know these things, etc, and so did the third party offshore companies account sales rep, and this is now at the executive level and my meeting is tomorrow and I want to go in with a lot of technical ammo to advocate best practices because I feel it will be cheaper in the long run (And I personally feel that is what the third party is worried about) for the company. My issue is from a technical level, I know its good long term but I'm having trouble with the ultra short term and 6 months term, and while its something I "know" I cant prove it with references and cited resources outside of one person (Robert C. Martin, aka Uncle Bob), as that is what I am being asked to do as I have been told having data from one person and only one person (Robert C Martin) is not good enough of an argument. Question: What are some resources I can cite directly (Title, year published, page number, quote) by well known experts in the field that explicitly say this use of "God" Objects/Classes/Systems is bad (or good, since we are looking for the most technically valid solution)? Research I have already done: I have a number of books here and I have searched their indexes for the use of the words "god object" and "god class". I found that oddly its almost never used and the copy of the GoF book I have for example, never uses it (At least according to the index in front of me) but I have found it in 2 books per the below, but I want more I can use. I checked the Wikipedia page for "God Object" and its currently a stub with little reference links so although I personally agree with that it says, It doesn't have much I can use in an environment where personal experience is not considered valid. The book cited is also considered too old to be valid by the people I am debating these technical points with as the argument they are making is that "it was once thought to be bad but nobody could prove it, and now modern software says "god" objects are good to use". I personally believe that this statement is incorrect, but I want to prove the truth, whatever it is. In Robert C Martin's "Agile Principles, Patterns, and Practices in C#" (ISBN: 0-13-185725-8, hardcover) where on page 266 it states "Everybody knows that god classes are a bad idea. We don't want to concentrate all the intelligence of a system into a single object or a single function. One of the goals of OOD is the partitioning and distribution of behavior into many classes and many function." -- And then goes on to say sometimes its better to use God Classes anyway sometimes (Citing micro-controllers as an example). In Robert C Martin's "Clean Code: A Handbook of Agile Software Craftsmanship" page 136 (And only this page) talks about the "God class" and calls it out as a prime example of a violation of the "classes should be small" rule he uses to promote the Single Responsibility Principle" starting on on page 138. The problem I have is all my references and citations come from the same person (Robert C. Martin), and am from the same single person/source. I am being told that because he is just one guy, my desire to not use "God Classes" is invalid and not accepted as a standard best practice in the software industry. Is this true? Am I doing things wrong from a technical perspective by trying to keep to the teaching of Uncle Bob? God Objects and Object Oriented Programming and Design: The more I think of this the more I think this is more something you learn when you study OOP and its never explicitly called out; Its implicit to good design is my thinking (Feel free to correct me, please, as I want to learn), The problem is I "know" this, but but not everybody does, so in this case its not considered a valid argument because I am effectively calling it out as universal truth when in fact most people are statistically ignorant of it since statistically most people are not programmers. Conclusion: I am at a loss on what to search for to get the best additional results to cite, since they are making a technical claim and I want to know the truth and be able to prove it with citations like a real engineer/scientist, even if I am biased against god objects due to my personal experience with code that used them. Any assistance or citations would be deeply appreciated.

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How to install iodbc in Ubuntu 12.10

- by Hanynowsky

I need to install the library iodbc (depends on libodbc2) in my Quantal machine. Yet there is creepy dependency problem. This was replaced somehow by unixodbc which I don't have, installed. Here is what I get when I try to install : sudo apt-get install libiodbc2-dev Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: libiodbc2-dev : Depends: libiodbc2 (= 3.52.7-2build2) but it is not going to be installed Depends: iodbc (= 3.52.7-2build2) but it is not going to be installed E: Unable to correct problems, you have held broken packages. I can tell that iodbc conflicts with odbcinst. Yet, I cannot remove it due to the following: sudo apt-get remove odbcinst Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: akonadi-backend-mysql calligra-l10n-engb kde-l10n-engb kdevelop-l10n kdevelop-php-docs-l10n kdevelop-php-l10n libakonadi-kabc4 libakonadi-notes4 libakonadiprotocolinternals1 libboost-thread1.49.0 libdmtx0a libgpgme++2 libkcalcore4 libkdgantt2 libkholidays4 libkimap4 libkldap4 libkmbox4 libkmime4 libkolabxml0 libkpgp4 libkresources4 libksieve4 libprison0 libqgpgme1 libqrencode3 libxerces-c3.1 Use 'apt-get autoremove' to remove them. The following packages will be REMOVED: akonadi-server k3b k3b-i18n katepart kde-runtime kdelibs-bin kdelibs5-plugins kdepim-runtime kdepim-strigi-plugins kdepimlibs-kio-plugins kdoctools kget kmag kmail kmix kmousetool ksystemlog kubuntu-debug-installer language-pack-kde-ar language-pack-kde-en libakonadi-calendar4 libakonadi-contact4 libakonadi-kcal4 libakonadi-kde4 libakonadi-kmime4 libcalendarsupport4 libincidenceeditorsng4 libk3b6 libkabc4 libkactivities-bin libkactivities6 libkalarmcal2 libkatepartinterfaces4 libkcal4 libkcalutils4 libkcddb4 libkde3support4 libkdepim4 libkdepimdbusinterfaces4 libkdewebkit5 libkemoticons4 libkfile4 libkgapi0 libkhtml5 libkio5 libkleo4 libkmanagesieve4 libkmediaplayer4 libknewstuff3-4 libknotifyconfig4 libkolab0 libkonq-common libkonq5abi1 libkontactinterface4 libkparts4 libkpimidentities4 libkpimtextedit4 libkpimutils4 libkprintutils4 libksieveui4 libktexteditor4 libktnef4 libktorrent4 libkworkspace4abi2 libkxmlrpcclient4 libmailcommon4 libmailimporter4 libmailtransport4 libmessagecomposer4 libmessagecore4 libmessagelist4 libmessageviewer4 libmicroblog4 libnepomuk4 libnepomukcore4abi1 libnepomukquery4a libnepomuksync4 libnepomukutils4 libplasma3 libsoprano4 libtemplateparser4 libvirtodbc0 nepomuk-core odbcinst odbcinst1debian2 plasma-scriptengine-javascript qapt-batch soprano-daemon virtuoso-minimal 0 upgraded, 0 newly installed, 89 to remove and 0 not upgraded. After this operation, 126 MB disk space will be freed. Do you want to continue [Y/n]? Other info: Why do the "iodbc" and "libmyodbc" packages conflict with each other? The root problem is that I need to use a new feature introduced in the latest MySQL Workbench builds (DB Migration) which uses odbc for that matter. Here is what Mysql doc says about it : Linux The Migration Wizard uses iODBC as a driver manager for all of its ODBC connections in Linux. This may give you some troubles because most Linux distributions provide ODBC drivers compiled against unixODBC. This is another driver manager not supported by MySQL Workbench so you won’t be able to use those drivers unless you compile them against iODBC. Here’s what you should do. Make sure that you have iODBC installed. If you are using Debian, Ubuntu or another Debian based distro, type this command in your terminal: $ sudo apt-get install iodbc libiodbc2-dev libpq-dev libssl-dev For RPM based distros (RedHat, Fedora, etc.) type this command instead of the previous one: $ sudo yum install iodbc iodbc-dev libpqxx-devel openssl-devel Now we need to install the PostgreSQL ODBC drivers. Download the psqlODBC source tarball from here. Use the latest version available for download. As of this writing the latest version corresponds to the file psqlodbc-09.01.0200.tar.gz. Extract this tarball to a directory in your hard drive and open a terminal and cd into that directory. Type this in the terminal window: $ ./configure --with-iodbc --enable-pthreads $ make $ sudo make install Verify that you have the file psqlodbcw.so in the /usr/local/lib directory. This package seems to pose the problem probably: dpkg -s odbcinst1debian2 Package: odbcinst1debian2 Status: install ok installed Priority: optional Section: libs Installed-Size: 241 Maintainer: Ubuntu Developers <[email protected]> Architecture: amd64 Multi-Arch: same Source: unixodbc Version: 2.2.14p2-5ubuntu4 Replaces: unixodbc (<< 2.1.1-2) Depends: libc6 (>= 2.14), libltdl7 (>= 2.4.2), odbcinst Pre-Depends: multiarch-support Breaks: libiodbc2, libmyodbc (<< 5.1.6-2), odbc-postgresql (<< 1:09.00.0310-1.1), tdsodbc (<< 0.82-8) Conflicts: odbcinst1, odbcinst1debian1 Description: Support library for accessing odbc ini files This package contains the libodbcinst library from unixodbc, a library used by ODBC drivers for reading their configuration settings from /etc/odbc.ini and ~/.odbc.ini. . Also contained in this package are the driver setup plugins, which describe the features supported by individual ODBC drivers. Homepage: http://www.unixodbc.org/ Original-Maintainer: Steve Langasek <[email protected]> I have no broken packages:

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Subterranean IL: Constructor constraints

- by Simon Cooper

The constructor generic constraint is a slightly wierd one. The ECMA specification simply states that it: constrains [the type] to being a concrete reference type (i.e., not abstract) that has a public constructor taking no arguments (the default constructor), or to being a value type. There seems to be no reference within the spec to how you actually create an instance of a generic type with such a constraint. In non-generic methods, the normal way of creating an instance of a class is quite different to initializing an instance of a value type. For a reference type, you use newobj: newobj instance void IncrementableClass::.ctor() and for value types, you need to use initobj: .locals init ( valuetype IncrementableStruct s1 ) ldloca 0 initobj IncrementableStruct But, for a generic method, we need a consistent method that would work equally well for reference or value types. Activator.CreateInstance<T> To solve this problem the CLR designers could have chosen to create something similar to the constrained. prefix; if T is a value type, call initobj, and if it is a reference type, call newobj instance void !!0::.ctor(). However, this solution is much more heavyweight than constrained callvirt. The newobj call is encoded in the assembly using a simple reference to a row in a metadata table. This encoding is no longer valid for a call to !!0::.ctor(), as different constructor methods occupy different rows in the metadata tables. Furthermore, constructors aren't virtual, so we would have to somehow do a dynamic lookup to the correct method at runtime without using a MethodTable, something which is completely new to the CLR. Trying to do this in IL results in the following verification error: newobj instance void !!0::.ctor() [IL]: Error: Unable to resolve token. This is where Activator.CreateInstance<T> comes in. We can call this method to return us a new T, and make the whole issue Somebody Else's Problem. CreateInstance does all the dynamic method lookup for us, and returns us a new instance of the correct reference or value type (strangely enough, Activator.CreateInstance<T> does not itself have a .ctor constraint on its generic parameter): .method private static !!0 CreateInstance<.ctor T>() { call !!0 [mscorlib]System.Activator::CreateInstance<!!0>() ret } Going further: compiler enhancements Although this method works perfectly well for solving the problem, the C# compiler goes one step further. If you decompile the C# version of the CreateInstance method above: private static T CreateInstance() where T : new() { return new T(); } what you actually get is this (edited slightly for space & clarity): .method private static !!T CreateInstance<.ctor T>() { .locals init ( [0] !!T CS$0$0000, [1] !!T CS$0$0001 ) DetectValueType: ldloca.s 0 initobj !!T ldloc.0 box !!T brfalse.s CreateInstance CreateValueType: ldloca.s 1 initobj !!T ldloc.1 ret CreateInstance: call !!0 [mscorlib]System.Activator::CreateInstance<T>() ret } What on earth is going on here? Looking closer, it's actually quite a clever performance optimization around value types. So, lets dissect this code to see what it does. The CreateValueType and CreateInstance sections should be fairly self-explanatory; using initobj for value types, and Activator.CreateInstance for reference types. How does the DetectValueType section work? First, the stack transition for value types: ldloca.s 0 // &[!!T(uninitialized)] initobj !!T // ldloc.0 // !!T box !!T // O[!!T] brfalse.s // branch not taken When the brfalse.s is hit, the top stack entry is a non-null reference to a boxed !!T, so execution continues to to the CreateValueType section. What about when !!T is a reference type? Remember, the 'default' value of an object reference (type O) is zero, or null. ldloca.s 0 // &[!!T(null)] initobj !!T // ldloc.0 // null box !!T // null brfalse.s // branch taken Because box on a reference type is a no-op, the top of the stack at the brfalse.s is null, and so the branch to CreateInstance is taken. For reference types, Activator.CreateInstance is called which does the full dynamic lookup using reflection. For value types, a simple initobj is called, which is far faster, and also eliminates the unboxing that Activator.CreateInstance has to perform for value types. However, this is strictly a performance optimization; Activator.CreateInstance<T> works for value types as well as reference types. Next... That concludes the initial premise of the Subterranean IL series; to cover the details of generic methods and generic code in IL. I've got a few other ideas about where to go next; however, if anyone has any itching questions, suggestions, or things you've always wondered about IL, do let me know.

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How to UEFI install Ubuntu 12.10?

- by Geezanansa

Running a newer FM1 motherboard which is using an AMD 3870k APU with a new 1TB HDD. Following the advice in the motherboard manual and https://help.ubuntu.com/community/UEFI have now got to grub option screen for UEFI install. see http://imgur.com/VW5vz The dvd.iso being used is Ubuntu 12.10 desktop amd64 from ubuntu .com. The hdd has had a gpt partition table made for, by using gparted when in a live desktop session when booted in bios mode. (*edit/update: Although the old cd updates on running it is an old kernel and it did make a gpt but that version of gparted uses fdisk whereas gdisk is required to make gpt. Think am going to have to spend more time here http://www.dedoimedo.com/computers/gparted.html lol Using the gparted from 12.10 live session to make partitions; following the guidance regarding this at https://help.ubuntu.com/community/UEFI#Creating_an_EFI_partition, but can only boot to grub option screen http://imgur.com/VW5vz when 12.10 options to "try ubuntu" or "install ubuntu" are selected they give errors as described below*) but after making the gpt decided to leave it unformatted/unallocated space with the intention of using installer to set up partitions. update-originally but gparted now sees hdd as http://imgur.com/hFIvm as described above. *Booting live dvd in EFI mode gives "Secure Boot not installed" just before grub kernel option list with the option to "install ubuntu" but get "can not read cd/0" and "the kernel must be loaded first" errors; when that option is selected. Any pointers on how to get installer going for UEFI install would be good. Thanks in advance. update: Hopefully these screenshots can help better highlight where i am going wrong or if there is something else going on http://imgur.com/g30RB, http://imgur.com/VW5vz, http://imgur.com/31E0q, http://imgur.com/bnuaG, http://imgur.com/y4KGu, http://imgur.com/3u2QE, http://imgur.com/n9lN3, http://imgur.com/FEKvz, http://imgur.com/hFIvm, update: Thank you fernando garcia for pointing me in the right direction to start the process of elimantion. What i have done since asking question is a little home work starting here http://askubuntu.com/faq#bounty and here http://askubuntu.com/questions/how-to-ask. Looking at other similar questions was good fun and found this 12.10 UEFI Secure Boot install the most relative in helping getting ubuntu to uefi install on my system. In response to wolverine's question this article was referred to http://web.dodds.net/~vorlon/wiki/blog/SecureBoot_in_Ubuntu_12.10/ This article in the first sentence gives a link to http://www.ubuntu.com/download which is where i downloaded the 12.10 desktop amd64 .iso(and others) but have been unable to do a efi install of ubuntu on this system and as this is a new system have ended up just going with bios installer running which at least puts my mind at ease that i have not bricked my new mobo.(had to do a clrcmos and flash to latest bios version) So it possibly could be the bios settings or the bios version being used that is problem. To try and eliminate bios version i can not get to post screen in order to id bios version being used. Pressing tab to show post instead of logo and trying to pausebreak to catch post is proving difficult. If logo screen in bios is disabled just get black screen no post shown and pressing tab does not show post. Appreciate using appropriate bios settings and latest 12.10 release should simply get uefi installer running when selected from the grub list (nice graphic details in Identifying if computer boots the cd in efi mode section at https://help.ubuntu.com/community/UEFI#Identifying_if_the_computer_boots_the_CD_in_EFI_mode) And to confirm the hdd is booting in efi mode https://help.ubuntu.com/community/UEFI#Identifying_if_the_computer_boots_the_HDD_in_EFI_mode running the command [ -d /sys/firmware/efi ] && echo "EFI boot on HDD" || echo "Legacy boot on HDD" gave Legacy boot on HDD This is as expected because i allowed the bios installer (which was 12.04 desktop amd64 after trying 12.10 desktop amd64 in efi mode) to run to get a working installation. Which is not what was intended or wished for but wanted to get a working os to bench test new mobo i.e. prove it is working. There are other options as in installing other bootmanagers/loaders but do not wish to do so as shim should get grub2 going that is after secure boot has been signed.(Now got rough idea what should happen just it aint happening. Is it possible ahci drivers are required?) Will post boot info script url of the updated config/setup. The original question asked seems irrelevant to what is being said in this update but as the problem is not resolved will keep on trying efi installing! i.e the problem is same as when question asked just trying to update. Have tried to edit and update the best i can!

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Normal maps red in OpenGL?

- by KaiserJohaan

I am using Assimp to import 3d models, and FreeImage to parse textures. The problem I am having is that the normal maps are actually red rather than blue when I try to render them as normal diffuse textures. http://i42.tinypic.com/289ing3.png When I open the images in a image-viewing program they do indeed show up as blue. Heres when I create the texture; OpenGLTexture::OpenGLTexture(const std::vector<uint8_t>& textureData, uint32_t textureWidth, uint32_t textureHeight, TextureType textureType, Logger& logger) : mLogger(logger), mTextureID(gNextTextureID++), mTextureType(textureType) { glGenTextures(1, &mTexture); CHECK_GL_ERROR(mLogger); glBindTexture(GL_TEXTURE_2D, mTexture); CHECK_GL_ERROR(mLogger); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, textureWidth, textureHeight, 0, glTextureFormat, GL_UNSIGNED_BYTE, &textureData[0]); CHECK_GL_ERROR(mLogger); glGenerateMipmap(GL_TEXTURE_2D); CHECK_GL_ERROR(mLogger); glBindTexture(GL_TEXTURE_2D, 0); CHECK_GL_ERROR(mLogger); } Here is my fragment shader. You can see I just commented out the normal-map parsing and treated the normal map texture as the diffuse texture to display it and illustrate the problem. As for the rest of the code it interacts as expected with the diffuse textures so I dont see a obvious problem there. "#version 330 \n \ \n \ layout(std140) uniform; \n \ \n \ const int MAX_LIGHTS = 8; \n \ \n \ struct Light \n \ { \n \ vec4 mLightColor; \n \ vec4 mLightPosition; \n \ vec4 mLightDirection; \n \ \n \ int mLightType; \n \ float mLightIntensity; \n \ float mLightRadius; \n \ float mMaxDistance; \n \ }; \n \ \n \ uniform UnifLighting \n \ { \n \ vec4 mGamma; \n \ vec3 mViewDirection; \n \ int mNumLights; \n \ \n \ Light mLights[MAX_LIGHTS]; \n \ } Lighting; \n \ \n \ uniform UnifMaterial \n \ { \n \ vec4 mDiffuseColor; \n \ vec4 mAmbientColor; \n \ vec4 mSpecularColor; \n \ vec4 mEmissiveColor; \n \ \n \ bool mHasDiffuseTexture; \n \ bool mHasNormalTexture; \n \ bool mLightingEnabled; \n \ float mSpecularShininess; \n \ } Material; \n \ \n \ uniform sampler2D unifDiffuseTexture; \n \ uniform sampler2D unifNormalTexture; \n \ \n \ in vec3 frag_position; \n \ in vec3 frag_normal; \n \ in vec2 frag_texcoord; \n \ in vec3 frag_tangent; \n \ in vec3 frag_bitangent; \n \ \n \ out vec4 finalColor; " " \n \ \n \ void CalcGaussianSpecular(in vec3 dirToLight, in vec3 normal, out float gaussianTerm) \n \ { \n \ vec3 viewDirection = normalize(Lighting.mViewDirection); \n \ vec3 halfAngle = normalize(dirToLight + viewDirection); \n \ \n \ float angleNormalHalf = acos(dot(halfAngle, normalize(normal))); \n \ float exponent = angleNormalHalf / Material.mSpecularShininess; \n \ exponent = -(exponent * exponent); \n \ \n \ gaussianTerm = exp(exponent); \n \ } \n \ \n \ vec4 CalculateLighting(in Light light, in vec4 diffuseTexture, in vec3 normal) \n \ { \n \ if (light.mLightType == 1) // point light \n \ { \n \ vec3 positionDiff = light.mLightPosition.xyz - frag_position; \n \ float dist = max(length(positionDiff) - light.mLightRadius, 0); \n \ \n \ float attenuation = 1 / ((dist/light.mLightRadius + 1) * (dist/light.mLightRadius + 1)); \n \ attenuation = max((attenuation - light.mMaxDistance) / (1 - light.mMaxDistance), 0); \n \ \n \ vec3 dirToLight = normalize(positionDiff); \n \ float angleNormal = clamp(dot(normalize(normal), dirToLight), 0, 1); \n \ \n \ float gaussianTerm = 0.0; \n \ if (angleNormal > 0.0) \n \ CalcGaussianSpecular(dirToLight, normal, gaussianTerm); \n \ \n \ return diffuseTexture * (attenuation * angleNormal * Material.mDiffuseColor * light.mLightIntensity * light.mLightColor) + \n \ (attenuation * gaussianTerm * Material.mSpecularColor * light.mLightIntensity * light.mLightColor); \n \ } \n \ else if (light.mLightType == 2) // directional light \n \ { \n \ vec3 dirToLight = normalize(light.mLightDirection.xyz); \n \ float angleNormal = clamp(dot(normalize(normal), dirToLight), 0, 1); \n \ \n \ float gaussianTerm = 0.0; \n \ if (angleNormal > 0.0) \n \ CalcGaussianSpecular(dirToLight, normal, gaussianTerm); \n \ \n \ return diffuseTexture * (angleNormal * Material.mDiffuseColor * light.mLightIntensity * light.mLightColor) + \n \ (gaussianTerm * Material.mSpecularColor * light.mLightIntensity * light.mLightColor); \n \ } \n \ else if (light.mLightType == 4) // ambient light \n \ return diffuseTexture * Material.mAmbientColor * light.mLightIntensity * light.mLightColor; \n \ else \n \ return vec4(0.0); \n \ } \n \ \n \ void main() \n \ { \n \ vec4 diffuseTexture = vec4(1.0); \n \ if (Material.mHasDiffuseTexture) \n \ diffuseTexture = texture(unifDiffuseTexture, frag_texcoord); \n \ \n \ vec3 normal = frag_normal; \n \ if (Material.mHasNormalTexture) \n \ { \n \ diffuseTexture = vec4(normalize(texture(unifNormalTexture, frag_texcoord).xyz * 2.0 - 1.0), 1.0); \n \ // vec3 normalTangentSpace = normalize(texture(unifNormalTexture, frag_texcoord).xyz * 2.0 - 1.0); \n \ //mat3 tangentToWorldSpace = mat3(normalize(frag_tangent), normalize(frag_bitangent), normalize(frag_normal)); \n \ \n \ // normal = tangentToWorldSpace * normalTangentSpace; \n \ } \n \ \n \ if (Material.mLightingEnabled) \n \ { \n \ vec4 accumLighting = vec4(0.0); \n \ \n \ for (int lightIndex = 0; lightIndex < Lighting.mNumLights; lightIndex++) \n \ accumLighting += Material.mEmissiveColor * diffuseTexture + \n \ CalculateLighting(Lighting.mLights[lightIndex], diffuseTexture, normal); \n \ \n \ finalColor = pow(accumLighting, Lighting.mGamma); \n \ } \n \ else { \n \ finalColor = pow(diffuseTexture, Lighting.mGamma); \n \ } \n \ } \n"; Why is this? does normal-map textures need some sort of special treatment in opengl?

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Design review for application facing memory issues

- by Mr Moose

I apologise in advance for the length of this post, but I want to paint an accurate picture of the problems my app is facing and then pose some questions below; I am trying to address some self inflicted design pain that is now leading to my application crashing due to out of memory errors. An abridged description of the problem domain is as follows; The application takes in a “dataset” that consists of numerous text files containing related data An individual text file within the dataset usually contains approx 20 “headers” that contain metadata about the data it contains. It also contains a large tab delimited section containing data that is related to data in one of the other text files contained within the dataset. The number of columns per file is very variable from 2 to 256+ columns. The original application was written to allow users to load a dataset, map certain columns of each of the files which basically indicating key information on the files to show how they are related as well as identify a few expected column names. Once this is done, a validation process takes place to enforce various rules and ensure that all the relationships between the files are valid. Once that is done, the data is imported into a SQL Server database. The database design is an EAV (Entity-Attribute-Value) model used to cater for the variable columns per file. I know EAV has its detractors, but in this case, I feel it was a reasonable choice given the disparate data and variable number of columns submitted in each dataset. The memory problem Given the fact the combined size of all text files was at most about 5 megs, and in an effort to reduce the database transaction time, it was decided to read ALL the data from files into memory and then perform the following; perform all the validation whilst the data was in memory relate it using an object model Start DB transaction and write the key columns row by row, noting the Id of the written row (all tables in the database utilise identity columns), then the Id of the newly written row is applied to all related data Once all related data had been updated with the key information to which it relates, these records are written using SqlBulkCopy. Due to our EAV model, we essentially have; x columns by y rows to write, where x can by 256+ and rows are often into the tens of thousands. Once all the data is written without error (can take several minutes for large datasets), Commit the transaction. The problem now comes from the fact we are now receiving individual files containing over 30 megs of data. In a dataset, we can receive any number of files. We’ve started seen datasets of around 100 megs coming in and I expect it is only going to get bigger from here on in. With files of this size, data can’t even be read into memory without the app falling over, let alone be validated and imported. I anticipate having to modify large chunks of the code to allow validation to occur by parsing files line by line and am not exactly decided on how to handle the import and transactions. Potential improvements I’ve wondered about using GUIDs to relate the data rather than relying on identity fields. This would allow data to be related prior to writing to the database. This would certainly increase the storage required though. Especially in an EAV design. Would you think this is a reasonable thing to try, or do I simply persist with identity fields (natural keys can’t be trusted to be unique across all submitters). Use of staging tables to get data into the database and only performing the transaction to copy data from staging area to actual destination tables. Questions For systems like this that import large quantities of data, how to you go about keeping transactions small. I’ve kept them as small as possible in the current design, but they are still active for several minutes and write hundreds of thousands of records in one transaction. Is there a better solution? The tab delimited data section is read into a DataTable to be viewed in a grid. I don’t need the full functionality of a DataTable, so I suspect it is overkill. Is there anyway to turn off various features of DataTables to make them more lightweight? Are there any other obvious things you would do in this situation to minimise the memory footprint of the application described above? Thanks for your kind attention.

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What Counts For A DBA: Foresight

- by drsql

Of all the valuable attributes of a DBA covered so far in this series, ranging from passion to humility to practicality, perhaps one of the most important attributes may turn out to be the most seemingly-nebulous: foresight. According to Free Dictionary foresight is the "perception of the significance and nature of events before they have occurred". Foresight does not come naturally to most people, as the parent of any teenager will attest. No matter how clearly you see their problems coming they won't listen, and have to fail before eventually (hopefully) learning for themselves. Having graduated from the school of hard knocks, the DBA, the naive teenager no longer, acquires the ability to foretell how events will unfold in response to certain actions or attitudes with the unerring accuracy of a doom-laden prophet. Like Simba in the Lion King, after a few blows to the head, we foretell that a sore head that will be the inevitable consequence of a swing of Rafiki's stick, and we take evasive action. However, foresight is about more than simply learning when to duck. It's about taking the time to understand and prevent the habits that caused the stick to swing in the first place. And based on this definition, I often think there is a lot less foresight on display in my industry than there ought to be. Most DBAs reading this blog will spot a line such as the following in a piece of "working" code, understand immediately why it is less than optimimum, and take evasive action. …WHERE CAST (columnName as int) = 1 However, the programmers who regularly write this sort of code clearly lack that foresight, and this and numerous other examples of similarly-malodorous code prevail throughout our industry (and provide premium-grade fertilizer for the healthy growth of many a consultant's bank account). Sometimes, perhaps harried by impatient managers and painfully tight deadlines, everyone makes mistakes. Yes, I too occasionally write code that "works", but basically stinks. When the problems manifest, it is sometimes accompanied by a sense of grim recognition that somewhere in me existed the foresight to know that that approach would lead to this problem. However, in the headlong rush, warning signs got overlooked, lessons learned previously, which could supply the foresight to the current project, were lost and not applied. Of course, the problem often is a simple lack of skills, training and knowledge in the relevant technology and/or business space; programmers and DBAs forced to do their best in the face of inadequate training, or to apply their skills in areas where they lack experience. However, often the problem goes deeper than this; I detect in some DBAs and programmers a certain laziness of attitude. They veer from one project to the next, going with "whatever works", unwilling or unable to take the time to understand where their actions are leading them. Of course, the whole "Agile" mindset is often interpreted to favor flexibility and rapid production over aiming to get things right the first time. The faster you try to travel in the dark, frequently changing direction, the more important it is to have someone who has the foresight to know at least roughly where you are heading. This is doubly true for the data tier which, no matter how you try to deny it, simply cannot be "redone" every month as you learn aspects of the world you are trying to model that, with a little bit of foresight, you would have seen coming. Sometimes, when as a DBA you can glance briefly at 200 lines of working SQL code and know instinctively why it will cause problems, foresight can feel like magic, but it isn't; it's more like muscle memory. It is acquired as the consequence of good experience, useful communication with those around you, and a willingness to learn continually, through continued education as well as from failure. Foresight can be deployed only by finding time to understand how the lessons learned from other DBAs, and other projects, can help steer the current project in the right direction. C.S. Lewis once said "The future is something which everyone reaches at the rate of sixty minutes an hour, whatever he does, whoever he is." It cannot be avoided; the quality of what you build now is going to affect you, and others, at some point in the future. Take the time to acquire foresight; it is a love letter to your future self, to say you cared.

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Closing the gap between strategy and execution with Oracle Business Intelligence 11g

- by manan.goel(at)oracle.com

Wikipedia defines strategy as a plan of action designed to achieve a particular goal. An example of this is General Electric's acquisitions and divestiture strategy (plan) designed to propel GE to number 1 or 2 place (goal) in every business segment that it operated in. Execution on the other hand can be defined as the actions taken to getting things done. In GE's case execution will be steps followed for mergers/acquisitions or divestiture. Business press has written extensively about the importance of both strategy and execution in achieving desired business objectives. Perhaps the quote from Thomas Edison says it best - "vision without execution is hallucination". Conversely, it can be said that "execution without vision" is well may be "wishful thinking". Research overwhelmingly point towards the wide gap between strategy and execution. According to a published study, 49% of surveyed executives perceive a gap between their organizations' ability to develop and communicate sound strategies and their ability to implement those strategies. Further, of these respondents, 64% don't have full confidence that their companies will be able to close the gap. Having established the severity and importance of the problem let's talk about the reasons for the strategy-execution gap. The common reasons include: - Lack of clearly defined goals - Lack of consistent measure of success - Lack of ownership - Lack of alignment - Lack of communication - Lack of proper execution - Lack of monitoring There are multiple approaches to solving the problem including organizational development practices, technology enablement etc. In most cases a combination of approaches is required to achieve the desired result. For the purposes of this discussion, I'll focus on technology. Imagine an integrated closed loop technology platform that automates the entire management cycle from defining strategy to assigning ownership to communicating goals to achieving alignment to collaboration to taking actions to monitoring progress and achieving mid course corrections. Besides, for best ROI and lowest TCO such a system should also have characteristics like: Complete - Full functionality - Rich end user access Open - Any data source - Any business application - Any technology stack Integrated - Common metadata - Common security - Common system management From a capabilities perspective the system should provide the following capabilities: Define - Strategy - Objectives - Ownership - KPI's Communicate - Pervasive - Collaborative - Role based - Secure Execute - Integrated - Intuitive - Secure - Ubiquitous Monitor - Multiple styles and formats - Exception based - Push & Pull Having talked about the business problem and outlined the blueprint for a technology solution, let's talk about how Oracle Business Intelligence 11g can help. Oracle Business Intelligence is a comprehensive business intelligence solution for reporting, ad hoc query and analysis, OLAP, dashboards and scorecards. Oracle's best in class BI platform is based on an architecturally integrated technology foundation that provides a unified end user experience and features a Common Enterprise Information Model, with common security, query request generation and optimization, and system management. The BI platform is · Complete - meaning it delivers all modes and styles of BI including reporting, ad hoc query and analysis, OLAP, dashboards and scorecards with a rich end user experience that includes visualization, collaboration, alerts and notifications, search and mobile access. · Open - meaning the BI platform integrates with any data source, ETL tool, business application, application server, security infrastructure, portal technology as well as any ODBC compliant third party analytical tool. The suite accesses data from multiple heterogeneous sources--including popular relational and multidimensional data sources and major ERP and CRM applications from Oracle and SAP. · Integrated - meaning the BI platform is based on an architecturally integrated technology foundation built on an open, standards based service oriented architecture. The platform features a common enterprise information model, common security model and a common configuration, deployment and systems management framework. To summarize, Oracle Business Intelligence is a comprehensive, integrated BI platform that lets you define strategy, identify objectives, assign ownership, define KPI's, collaborate, take action, monitor, report and do course corrections all form a single interface and a single system. The platform's integrated metadata model and task based design ensures that the entire workflow from defining strategy to execution to monitoring is completely integrated delivering end to end visibility, transparency and agility. Click here to learn more about Oracle BI 11g.

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Collision Detection, player correction

- by DoomStone

I am having some problems with collision detection, I have 2 types of objects excluding the player. Tiles and what I call MapObjects. The tiles are all 16x16, where the MapObjects can be any size, but in my case they are all 16x16. When my player runs along the mapobjects or tiles, it get verry jaggy. The player is unable to move right, and will get warped forward when moving left. I have found the problem, and that is my collision detection will move the player left/right if colliding the object from the side, and up/down if collision from up/down. Now imagine that my player is sitting on 2 tiles, at (10,12) and (11,12), and the player is mostly standing on the (11,12) tile. The collision detection will first run on then (10,12) tile, it calculates the collision depth, and finds that is is a collision from the side, and therefore move the object to the right. After, it will do the collision detection with (11,12) and it will move the character up. So the player will not fall down, but are unable to move right. And when moving left, the same problem will make the player warp forward. This problem have been bugging me for a few days now, and I just can't find a solution! Here is my code that does the collision detection. public void ApplyObjectCollision(IPhysicsObject obj, List<IComponent> mapObjects, TileMap map) { PhysicsVariables physicsVars = GetPhysicsVariables(); Rectangle bounds = ((IComponent)obj).GetBound(); int leftTile = (int)Math.Floor((float)bounds.Left / map.GetTileSize()); int rightTile = (int)Math.Ceiling(((float)bounds.Right / map.GetTileSize())) - 1; int topTile = (int)Math.Floor((float)bounds.Top / map.GetTileSize()); int bottomTile = (int)Math.Ceiling(((float)bounds.Bottom / map.GetTileSize())) - 1; // Reset flag to search for ground collision. obj.IsOnGround = false; // For each potentially colliding tile, for (int y = topTile; y <= bottomTile; ++y) { for (int x = leftTile; x <= rightTile; ++x) { IComponent tile = map.Get(x, y); if (tile != null) { bounds = HandelCollision(obj, tile, bounds, physicsVars); } } } // Handel collision for all Moving objects foreach (IComponent mo in mapObjects) { if (mo == obj) continue; if (mo.GetBound().Intersects(((IComponent)obj).GetBound())) { bounds = HandelCollision(obj, mo, bounds, physicsVars); } } } private Rectangle HandelCollision(IPhysicsObject obj, IComponent objb, Rectangle bounds, PhysicsVaraibales physicsVars) { // If this tile is collidable, SpriteCollision collision = ((IComponent)objb).GetCollisionType(); if (collision != SpriteCollision.Passable) { // Determine collision depth (with direction) and magnitude. Rectangle tileBounds = ((IComponent)objb).GetBound(); Vector2 depth = bounds.GetIntersectionDepth(tileBounds); if (depth != Vector2.Zero) { float absDepthX = Math.Abs(depth.X); float absDepthY = Math.Abs(depth.Y); // Resolve the collision along the shallow axis. if (absDepthY <= absDepthX || collision == SpriteCollision.Platform) { // If we crossed the top of a tile, we are on the ground. if (obj.PreviousBound.Bottom <= tileBounds.Top) obj.IsOnGround = true; // Ignore platforms, unless we are on the ground. if (collision == SpriteCollision.Impassable || obj.IsOnGround) { // Resolve the collision along the Y axis. ((IComponent)obj).Position = new Vector2(((IComponent)obj).Position.X, ((IComponent)obj).Position.Y + depth.Y); // If we hit something about us, remove all velosity upwards if (depth.Y > 0 && obj.IsJumping) { obj.Velocity = new Vector2(obj.Velocity.X, 0); obj.JumpTime = physicsVars.MaxJumpTime; } // Perform further collisions with the new bounds. return ((IComponent)obj).GetBound(); } } else if (collision == SpriteCollision.Impassable) // Ignore platforms. { // Resolve the collision along the X axis. ((IComponent)obj).Position = new Vector2(((IComponent)obj).Position.X + depth.X, ((IComponent)obj).Position.Y); // Perform further collisions with the new bounds. return ((IComponent)obj).GetBound(); } } } return bounds; } Update: I have uploaded the source code, if you want to look that through. I think that my general approach might be wrong when i am working with small tiles, I have also be unable to find any good information on physics and collision detection in Platform games. http://dl.dropbox.com/u/3181816/Sogaard.Games.SuperMario.rar

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PhP Login/Register system [migrated]

- by Marian

I found this good tutorial on creating a login/register system using PhP and MySQL. The forum is around 5 years old (edited last year) but it can still be usefull. Beginner Simple Register-Login system There seems to be an issue with both login and register pages. <?php function register_form(){ $date = date('D, M, Y'); echo "<form action='?act=register' method='post'>" ."Username: <input type='text' name='username' size='30'><br>" ."Password: <input type='password' name='password' size='30'><br>" ."Confirm your password: <input type='password' name='password_conf' size='30'><br>" ."Email: <input type='text' name='email' size='30'><br>" ."<input type='hidden' name='date' value='$date'>" ."<input type='submit' value='Register'>" ."</form>"; } function register(){ $connect = mysql_connect("host", "username", "password"); if(!$connect){ die(mysql_error()); } $select_db = mysql_select_db("database", $connect); if(!$select_db){ die(mysql_error()); } $username = $_REQUEST['username']; $password = $_REQUEST['password']; $pass_conf = $_REQUEST['password_conf']; $email = $_REQUEST['email']; $date = $_REQUEST['date']; if(empty($username)){ die("Please enter your username!<br>"); } if(empty($password)){ die("Please enter your password!<br>"); } if(empty($pass_conf)){ die("Please confirm your password!<br>"); } if(empty($email)){ die("Please enter your email!"); } $user_check = mysql_query("SELECT username FROM users WHERE username='$username'"); $do_user_check = mysql_num_rows($user_check); $email_check = mysql_query("SELECT email FROM users WHERE email='$email'"); $do_email_check = mysql_num_rows($email_check); if($do_user_check > 0){ die("Username is already in use!<br>"); } if($do_email_check > 0){ die("Email is already in use!"); } if($password != $pass_conf){ die("Passwords don't match!"); } $insert = mysql_query("INSERT INTO users (username, password, email) VALUES ('$username', '$password', '$email')"); if(!$insert){ die("There's little problem: ".mysql_error()); } echo $username.", you are now registered. Thank you!<br><a href=login.php>Login</a> | <a href=index.php>Index</a>"; } switch($act){ default; register_form(); break; case "register"; register(); break; } ?> Once pressed the register button the page does nothing, fields are erased and no data is added inside the database or error given. I tought that the problem might be the switch($act){ part so I removed it and changed the page using a require require('connect.php'); where connect.php is <?php mysql_connect("localhost","host","password"); mysql_select_db("database"); ?> Removed the function register_form(){ and echo part turning it into an HTML code: <form action='register' method='post'> Username: <input type='text' name='username' size='30'><br> Password: <input type='password' name='password' size='30'><br> Confirm your password: <input type='password' name='password_conf' size='30'><br> Email: <input type='text' name='email' size='30'><br> <input type='hidden' name='date' value='$date'> <input type='submit' name="register" value='Register'> </form> And instead of having a function register(){ I replaced it with a if($register){ So when the Register button is pressed it runs the php code, but this edit doesn't seem to work either. So what can the problem be? If needed I can re-add this code on my Domain The login page has the same issue, nothing happens when the button is pressed beside emptying the fields.

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Actionscript 3.0 - Enemies do not move right in my platformer game

- by Christian Basar

I am making a side-scrolling platformer game in Flash (Actionscript 3.0). I have made lots of progress lately, but I have come across a new problem. I will give some background first. My game level's terrain (or 'floor') is referenced by a MovieClip variable called 'floor.' My desire is to have the Player and enemy characters walk along the terrain. I have gotten the Player character to move on the terrain just fine; he walks up/down hills and falls whenever there is no ground beneath him. Here is the code I created to allow the Player to follow the terrain correctly. Much more code is used to control the Player, but only this code deals with the Player character's following of the terrain and gravity. // If the Player's not on the ground (not touching the 'floor' MovieClip)... if (!onGround) { // Disable ducking downKeyPressed = false; // Increase the Player's 'y' position by his 'y' velocity player.y += playerYVel; } // Increase the 'playerYVel' variable so that the Player will fall // progressively faster down the screen. This code technically // runs "all the time" but in reality it only affects the player // when he's off the ground. playerYVel += gravity; // Give the Player a terminal velocity of 15 px/frame if (playerYVel > 15) { playerYVel = 15; } // If the Player has not hit the 'floor,' increase his falling //speed if (! floor.hitTestPoint(player.x, player.y, true)) { player.y += playerYVel; // The Player is not on the ground when he's not touching it onGround = false; } Since getting this code to work for the Player, I have created a 'SkullDemon' class, which is one of the planned enemies for my game. I want the 'SkullDemon' objects to move along the terrain like the Player does. With lots of great help, I have already coded the EventListeners, etc. necessary for the 'SkullDemons' to move. Unfortunately, I am having trouble getting them to move along the terrain. In fact, they do not touch the terrain at all; they move along the top of the boundary of the 'floor' MovieClip! I had a simple text diagram showing what I mean, but unfortunately Stackoverflow does not format it correctly. I hope my problem is clear from my description. Strangely enough, my code for the Player's movement and the 'SkullDemon's' movement is almost exactly the same, yet the 'SkullDemons' do not move like the Player does. Here is my code for the SkullDemon movement: // Move all of the Skull Demons using this method protected function moveSkullDemons():void { // Go through the whole 'skullDemonContainer' for (var skullDi:int = 0; skullDi < skullDemonContainer.numChildren; skullDi++) { // Set the SkullDemon 'instance' variable to equal the current SkullDemon skullDIns = SkullDemon(skullDemonContainer.getChildAt(skullDi)); // For now, just move the Skull Demons left at 5 units per second skullDIns.x -= 5; // If the Skull Demon has not hit the 'floor,' increase his falling //speed if (! floor.hitTestPoint(skullDIns.x, skullDIns.y, true)) { // Increase the Skull Demon's 'y' position by his 'y' velocity skullDIns.y += skullDIns.sdYVel; // The Skull Demon is not on the ground when he's not touching it skullDIns.sdOnGround = false; } // Increase the 'sdYVel' variable so that the Skull Demon will fall // progressively faster down the screen. This code technically // runs "all the time" but in reality it only affects the Skull Demon // when he's off the ground. if (! skullDIns.sdOnGround) { skullDIns.sdYVel += skullDIns.sdGravity; // Give the Skull Demon a terminal velocity of 15 px/frame if (skullDIns.sdYVel > 15) { skullDIns.sdYVel = 15; } } // What happens when the Skull Demon lands on the ground after a fall? // The Skull Demon is only on the ground ('onGround == true') when // the ground is touching the Skull Demon MovieClip's origin point, // which is at the Skull Demon's bottom centre for (var i:int = 0; i < 10; i++) { // The Skull Demon is only on the ground ('onGround == true') when // the ground is touching the Skull Demon MovieClip's origin point, // which is at the Skull Demon's bottom centre if (floor.hitTestPoint(skullDIns.x, skullDIns.y, true)) { skullDIns.y = skullDIns.y; // Set the Skull Demon's y-axis speed to 0 skullDIns.sdYVel = 0; // The Skull Demon is on the ground again skullDIns.sdOnGround = true; } } } } // End of 'moveSkullDemons()' function It is almost like the 'SkullDemons' are interacting with the 'floor' MovieClip using the hitTestObject() function, and not the hitTestPoint() function which is what I want, and which works for the Player character. I am confused about this problem and would appreciate any help you could give me. Thanks!

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Could not connect to wireless unitl reboot (nl80211)

- by user107410

I'm using Samsung NP900X3C. I have problem with occasionally connecting to WIFI, with Ubuntu 12.10. Sometimes my computer could not connect to WIFI "blab", neither after reboot computer. Only solution is to restart WIFI hotspot. It's public WIFI, used by many users, that don't have that problem. My /var/log/syslog: Nov 12 10:09:39 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:39 k15 kernel: [ 8.908610] wlan0: authenticate with 64:70:02:89:7c:d7 Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 12 10:09:39 k15 kernel: [ 8.915032] wlan0: send auth to 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:09:39 k15 wpa_supplicant[1308]: wlan0: Trying to associate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:39 k15 kernel: [ 8.916753] wlan0: authenticated Nov 12 10:09:39 k15 kernel: [ 8.916839] wlan0: waiting for beacon from 64:70:02:89:7c:d7 Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: authenticating -> associating Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associating -> disconnected Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: disconnected -> scanning Nov 12 10:09:42 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:42 k15 kernel: [ 12.386212] wlan0: authenticate with 64:70:02:89:7c:d7 Nov 12 10:09:42 k15 wpa_supplicant[1308]: wlan0: Trying to associate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:42 k15 kernel: [ 12.389114] wlan0: send auth to 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:09:42 k15 kernel: [ 12.391021] wlan0: authenticated Nov 12 10:09:42 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 12 10:09:42 k15 kernel: [ 12.391332] wlan0: waiting for beacon from 64:70:02:89:7c:d7 Nov 12 10:09:42 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: authenticating -> associating Nov 12 10:09:43 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associating -> disconnected Nov 12 10:09:43 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: disconnected -> scanning Nov 12 10:09:46 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) and after restart WiFi, I could connect: Nov 12 10:11:51 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: inactive -> scanning Nov 12 10:11:55 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:11:55 k15 kernel: [ 144.445154] wlan0: authenticate with 64:70:02:89:7c:d7 Nov 12 10:11:55 k15 kernel: [ 144.453994] wlan0: send auth to 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:11:55 k15 wpa_supplicant[1308]: wlan0: Trying to associate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 12 10:11:55 k15 kernel: [ 144.455860] wlan0: authenticated Nov 12 10:11:55 k15 kernel: [ 144.458681] wlan0: associate with 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: authenticating -> associating Nov 12 10:11:55 k15 kernel: [ 144.462799] wlan0: RX AssocResp from 64:70:02:89:7c:d7 (capab=0x431 status=0 aid=9) Nov 12 10:11:55 k15 kernel: [ 144.486368] wlan0: associated Nov 12 10:11:55 k15 wpa_supplicant[1308]: wlan0: Associated with 64:70:02:89:7c:d7 Nov 12 10:11:55 k15 kernel: [ 144.487435] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associating -> associated Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associated -> 4-way handshake This problem is appearing regulary. My WiFi device control is nl80211. Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): using nl80211 for WiFi device control Nov 12 10:09:32 k15 NetworkManager[1004]: <warn> (wlan0): driver supports Access Point (AP) mode Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): new 802.11 WiFi device (driver: 'iwlwifi' ifindex: 3) Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): exported as /org/freedesktop/NetworkManager/Devices/0 Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): now managed Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): bringing up device.

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OpenGL (glx) not working with ubuntu 12.10

- by user26766

It all started when I installed nvidia's own (download from website) driver. Uninstalling it and reverting back to nvidia-current didn't solve the problem, so I have been playing with this for a while. It seems glx support is missing, and my intel graphics is not responding. gnome loads only in fallback mode. Here are some outputs: glxinfo name of display: :0.0 Error: couldn't find RGB GLX visual or fbconfig glxgears Error: couldn't get an RGB, Double-buffered visual optirun glxgears works fine lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) 01:00.0 VGA compatible controller: NVIDIA Corporation GF108 [GeForce GT 540M] (rev ff) Here's the content of log file when just after running glxinfo: less /var/log/Xorg.0.log | grep gl [ 112.156] (II) LoadModule: "glx" [ 112.157] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so [ 112.157] (II) Module glx: vendor="X.Org Foundation" [ 112.157] (II) UnloadModule: "glx" [ 112.157] (II) Unloading glx [ 112.157] (EE) Failed to load module "glx" (module requirement mismatch, 0) Some more info... lsmod Module Size Used by bbswitch 13612 0 pci_stub 12623 1 vboxpci 23195 0 vboxnetadp 25671 0 vboxnetflt 23480 0 vboxdrv 320372 3 vboxpci,vboxnetadp,vboxnetflt parport_pc 32689 0 ppdev 17074 0 bnep 18141 2 rfcomm 46620 12 binfmt_misc 17501 1 snd_hda_codec_hdmi 32049 1 snd_hda_codec_realtek 78147 1 joydev 17458 0 uvcvideo 76750 0 videobuf2_core 32852 1 uvcvideo videodev 120310 2 uvcvideo,videobuf2_core videobuf2_vmalloc 12861 1 uvcvideo videobuf2_memops 13405 1 videobuf2_vmalloc snd_hda_intel 33492 3 coretemp 13401 0 kvm_intel 132760 0 arc4 12530 2 snd_hda_codec 134213 3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel kvm 414111 1 kvm_intel iwlwifi 386837 0 i915 520799 2 snd_hwdep 17699 1 snd_hda_codec snd_pcm 96668 3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec psmouse 100389 0 drm_kms_helper 49113 1 i915 ghash_clmulni_intel 13221 0 snd_seq_midi 13325 0 snd_rawmidi 30513 1 snd_seq_midi btusb 22475 0 drm 288436 3 i915,drm_kms_helper serio_raw 13216 0 snd_seq_midi_event 14900 1 snd_seq_midi snd_seq 61555 2 snd_seq_midi,snd_seq_midi_event mac80211 535936 1 iwlwifi bluetooth 209249 22 bnep,rfcomm,btusb snd_timer 29426 2 snd_pcm,snd_seq snd_seq_device 14498 3 snd_seq_midi,snd_rawmidi,snd_seq snd 78921 16 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device cfg80211 206797 2 iwlwifi,mac80211 aesni_intel 51038 1 cryptd 20404 2 ghash_clmulni_intel,aesni_intel aes_x86_64 17256 1 aesni_intel dell_wmi 12682 0 sparse_keymap 13891 1 dell_wmi dcdbas 14439 0 i2c_algo_bit 13414 1 i915 microcode 22804 0 lpc_ich 17062 0 soundcore 15048 1 snd snd_page_alloc 18485 2 snd_hda_intel,snd_pcm video 19391 1 i915 mac_hid 13206 0 wmi 19071 1 dell_wmi mei 40691 0 lp 17760 0 parport 46346 3 parport_pc,ppdev,lp ahci 25721 3 libahci 31192 1 ahci atl1c 41102 0 how can I fix this? any ideas? Here is another thing I've tried: sudo apt-get purge nvidia* sudo reboot sudo apt-get install bumblebee bumblebee-nvidia didn't make any difference. The most relevant post I found on the web was this: http://ubuntuforums.org/archive/index.php/t-1722306.html Here it's explained that the problem is with the priority of shared libraries that are loaded for glxinfo. Here's what I get when I look up the libraries: linux-vdso.so.1 => (0x00007fff6bf8b000) libGL.so.1 => /usr/lib/x86_64-linux-gnu/mesa/libGL.so.1 (0x00007f22d6ccd000) libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007f22d6993000) libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f22d65d3000) libglapi.so.0 => /usr/lib/x86_64-linux-gnu/libglapi.so.0 (0x00007f22d63ad000) libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007f22d619b000) libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007f22d5f97000) libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007f22d5d91000) libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f22d5b8f000) libxcb-glx.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-glx.so.0 (0x00007f22d5977000) libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f22d5759000) libXxf86vm.so.1 => /usr/lib/x86_64-linux-gnu/libXxf86vm.so.1 (0x00007f22d5553000) libdrm.so.2 => /usr/lib/x86_64-linux-gnu/libdrm.so.2 (0x00007f22d5346000) libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f22d5129000) libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f22d4f25000) /lib64/ld-linux-x86-64.so.2 (0x00007f22d6f54000) libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007f22d4d20000) libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f22d4b1a000) librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f22d4911000) It seems "mesa" instead of nvidia-current is being used. However I didn't find any obvious link to /lib/nvidia-current in /etc/ld.so.conf (where the directories containing the shared libraries are listed). I don't know if there's anything missing or if this is normal. thanks, UPDATE: The problem was solved by updating to Ubuntu 13.04. It seems bumblebee was to blame, but I'm not sure what was going wrong...

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The Unintended Consequences of Sound Security Policy

- by Tanu Sood

v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Author: Kevin Moulton, CISSP, CISM Meet the Author: Kevin Moulton, Senior Sales Consulting Manager, Oracle Kevin Moulton, CISSP, CISM, has been in the security space for more than 25 years, and with Oracle for 7 years. He manages the East Enterprise Security Sales Consulting Team. He is also a Distinguished Toastmaster. Follow Kevin on Twitter at twitter.com/kevin_moulton, where he sometimes tweets about security, but might also tweet about running, beer, food, baseball, football, good books, or whatever else grabs his attention. Kevin will be a regular contributor to this blog so stay tuned for more posts from him. When I speak to a room of IT administrators, I like to begin by asking them if they have implemented a complex password policy. Generally, they all nod their heads enthusiastically. I ask them if that password policy requires long passwords. More nodding. I ask if that policy requires upper and lower case letters – faster nodding – numbers – even faster – special characters – enthusiastic nodding all around! I then ask them if their policy also includes a requirement for users to regularly change their passwords. Now we have smiles with the nodding! I ask them if the users have different IDs and passwords on the many systems that they have access to. Of course! I then ask them if, when they walk around the building, they see something like this: Thanks to Jake Ludington for the nice example. Can these administrators be faulted for their policies? Probably not but, in the end, end-users will find a way to get their job done efficiently. Post-It Notes to the rescue! I was visiting a business in New York City one day which was a perfect example of this problem. First I walked up to the security desk and told them where I was headed. They asked me if they should call upstairs to have someone escort me. Is that my call? Is that policy? I said that I knew where I was going, so they let me go. Having the conference room number handy, I wandered around the place in a search of my destination. As I walked around, unescorted, I noticed the post-it note problem in abundance. Had I been so inclined, I could have logged in on almost any machine and into any number of systems. When I reached my intended conference room, I mentioned my post-it note observation to the two gentlemen with whom I was meeting. One of them said, “You mean like this,” and he produced a post it note full of login IDs and passwords from his breast pocket! I gave him kudos for not hanging the list on his monitor. We then talked for the rest of the meeting about the difficulties faced by the employees due to the security policies. These policies, although well-intended, made life very difficult for the end-users. Most users had access to 8 to 12 systems, and the passwords for each expired at a different times. The post-it note solution was understandable. Who could remember even half of them? What could this customer have done differently? I am a fan of using a provisioning system, such as Oracle Identity Manager, to manage all of the target systems. With OIM, and email could be automatically sent to all users when it was time to change their password. The end-users would follow a link to change their password on a web page, and then OIM would propagate that password out to all of the systems that the user had access to, even if the login IDs were different. Another option would be an Enterprise Single-Sign On Solution. With Oracle eSSO, all of a user’s credentials would be stored in a central, encrypted credential store. The end-user would only have to login to their machine each morning and then, as they moved to each new system, Oracle eSSO would supply the credentials. Good-bye post-it notes! 3M may be disappointed, but your end users will thank you. I hear people say that this post-it note problem is not a big deal, because the only people who would see the passwords are fellow employees. Do you really know who is walking around your building? What are the password policies in your business? How do the end-users respond?

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Best Practices Generating WebService Proxies for Oracle Sales Cloud (Fusion CRM)

- by asantaga

I've recently been building a REST Service wrapper for Oracle Sales Cloud and initially all was going well, however as soon as I added all of my Web Service proxies I started to get weird errors.. My project structure looks like this What I found out was if I only had the InteractionsService & OpportunityService WebService Proxies then all worked ok, but as soon as I added the LocationsService Proxy, I would start to see strange JAXB errors. Example of the error message Exception in thread "main" javax.xml.ws.WebServiceException: Unable to create JAXBContextat com.sun.xml.ws.model.AbstractSEIModelImpl.createJAXBContext(AbstractSEIModelImpl.java:164)at com.sun.xml.ws.model.AbstractSEIModelImpl.postProcess(AbstractSEIModelImpl.java:94)at com.sun.xml.ws.model.RuntimeModeler.buildRuntimeModel(RuntimeModeler.java:281)at com.sun.xml.ws.client.WSServiceDelegate.buildRuntimeModel(WSServiceDelegate.java:762)at weblogic.wsee.jaxws.spi.WLSProvider$ServiceDelegate.buildRuntimeModel(WLSProvider.java:982)at com.sun.xml.ws.client.WSServiceDelegate.createSEIPortInfo(WSServiceDelegate.java:746)at com.sun.xml.ws.client.WSServiceDelegate.addSEI(WSServiceDelegate.java:737)at com.sun.xml.ws.client.WSServiceDelegate.getPort(WSServiceDelegate.java:361)at weblogic.wsee.jaxws.spi.WLSProvider$ServiceDelegate.internalGetPort(WLSProvider.java:934)at weblogic.wsee.jaxws.spi.WLSProvider$ServiceDelegate$PortClientInstanceFactory.createClientInstance(WLSProvider.java:1039)...... Looking further down I see the error message is related to JAXB not being able to find an objectFactory for one of its types Caused by: java.security.PrivilegedActionException: com.sun.xml.bind.v2.runtime.IllegalAnnotationsException: 6 counts of IllegalAnnotationExceptionsThere's no ObjectFactory with an @XmlElementDecl for the element {http://xmlns.oracle.com/apps/crmCommon/activities/activitiesService/}AssigneeRsrcOrgIdthis problem is related to the following location:at protected javax.xml.bind.JAXBElement com.oracle.xmlns.apps.crmcommon.activities.activitiesservice.ActivityAssignee.assigneeRsrcOrgId at com.oracle.xmlns.apps.crmcommon.activities.activitiesservice.ActivityAssignee This is very strange... My first thoughts are that when I generated the WebService Proxy I entered the package name as "oracle.demo.pts.fusionproxy.servicename" and left the generated types as blank. This way all the generated types get put into the same package hierarchy and when deployed they get merged... Sounds resaonable and appears to work but not in this case.. To resolve this I regenerate the proxy but this time setting : Package name : To the name of my package eg. oracle.demo.pts.fusionproxy.interactionsRoot Package for Generated Types : Package where the types will be generated to, e.g. oracle.demo.pts.fusionproxy.SalesParty.types When I ran the application now, it all works , awesome eh???? Alas no, there is a serious side effect. The problem now is that to help coding I've created a collection of helper classes , these helper classes take parameters which use some of the "generic" datatypes, like FindCriteria. e.g. This wont work any more public static FindCriteria createCustomFindCriteria(FindCriteria pFc,String pAttributes) Here lies a gremlin of a problem.. I cant use this method anymore, this is because the FindCriteria datatype is now being defined two, or more times, in the generated code for my project. If you leave the Root Package for types blank it will get generated to com.oracle.xmlns, and if you populate it then it gets generated to your custom package.. The two datatypes look the same, sound the same (and if this were a duck would sound the same), but THEY ARE NOT THE SAME... Speaking to development, they recommend you should not be entering anything in the Root Packages section, so the mystery thickens why does it work.. Well after spending sometime with some colleagues of mine in development we've identified the issue.. Alas different parts of Oracle Fusion Development have multiple schemas with the same namespace, when the WebService generator generates its classes its not seeing the other schemas properly and not generating the Object Factories correctly... Thankfully I've found a workaround Solution Overview When generating the proxies leave the Root Package for Generated Types BLANK When you have finished generating your proxies, use the JAXB tool XJC and generate Java classes for all datatypes Create a project within your JDeveloper11g workspace and import the java classes into this project Final bit.. within the project dependencies ensure that the JAXB/XJC generated classes are "FIRST" in the classpath Solution Details Generate the WebServices SOAP proxies When generating the proxies your generation dialog should look like this Ensure the "unwrap" parameters is selected, if it isn't then that's ok, it simply means when issuing a "get" you need to extract out the Element Generate the JAXB Classes using XJC XJC provides a command line switch called -wsdl, this (although is experimental/beta) , accepts a HTTP WSDL and will generate the relevant classes. You can put these into a single batch/shell script xjc -wsdl https://fusionservername:443/appCmmnCompInteractions/InteractionService?wsdlxjc -wsdl https://fusionservername443/opptyMgmtOpportunities/OpportunityService?wsdl Create Project in JDeveloper to store the XJC "generated" JAXB classes Within the project folder create a filesystem folder called "src" and copy the generated files into this folder. JDeveloper11g should then see the classes and display them, if it doesnt try clicking the "refresh" button In your main project ensure that the JDeveloper XJC project is selected as a dependancy and IMPORTANT make sure it is at the top of the list. This ensures that the classes are at the front of the classpath And voilà.. Hopefully you wont see any JAXB generation errors and you can use common datatypes interchangeably in your project, (e.g. FindCriteria etc)

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Namespaces are obsolete

- by Bertrand Le Roy

To those of us who have been around for a while, namespaces have been part of the landscape. One could even say that they have been defining the large-scale features of the landscape in question. However, something happened fairly recently that I think makes this venerable structure obsolete. Before I explain this development and why it’s a superior concept to namespaces, let me recapitulate what namespaces are and why they’ve been so good to us over the years… Namespaces are used for a few different things: Scope: a namespace delimits the portion of code where a name (for a class, sub-namespace, etc.) has the specified meaning. Namespaces are usually the highest-level scoping structures in a software package. Collision prevention: name collisions are a universal problem. Some systems, such as jQuery, wave it away, but the problem remains. Namespaces provide a reasonable approach to global uniqueness (and in some implementations such as XML, enforce it). In .NET, there are ways to relocate a namespace to avoid those rare collision cases. Hierarchy: programmers like neat little boxes, and especially boxes within boxes within boxes. For some reason. Regular human beings on the other hand, tend to think linearly, which is why the Windows explorer for example has tried in a few different ways to flatten the file system hierarchy for the user. 1 is clearly useful because we need to protect our code from bleeding effects from the rest of the application (and vice versa). A language with only global constructs may be what some of us started programming on, but it’s not desirable in any way today. 2 may not be always reasonably worth the trouble (jQuery is doing fine with its global plug-in namespace), but we still need it in many cases. One should note however that globally unique names are not the only possible implementation. In fact, they are a rather extreme solution. What we really care about is collision prevention within our application. What happens outside is irrelevant. 3 is, more than anything, an aesthetical choice. A common convention has been to encode the whole pedigree of the code into the namespace. Come to think about it, we never think we need to import “Microsoft.SqlServer.Management.Smo.Agent” and that would be very hard to remember. What we want to do is bring nHibernate into our app. And this is precisely what you’ll do with modern package managers and module loaders. I want to take the specific example of RequireJS, which is commonly used with Node. Here is how you import a module with RequireJS: var http = require("http"); .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 is of course importing a HTTP stack module into the code. There is no noise here. Let’s break this down. Scope (1) is provided by the one scoping mechanism in JavaScript: the closure surrounding the module’s code. Whatever scoping mechanism is provided by the language would be fine here. Collision prevention (2) is very elegantly handled. Whereas relocating is an afterthought, and an exceptional measure with namespaces, it is here on the frontline. You always relocate, using an extremely familiar pattern: variable assignment. We are very much used to managing our local variable names and any possible collision will get solved very easily by picking a different name. Wait a minute, I hear some of you say. This is only taking care of collisions on the client-side, on the left of that assignment. What if I have two libraries with the name “http”? Well, You can better qualify the path to the module, which is what the require parameter really is. As for hierarchical organization, you don’t really want that, do you? RequireJS’ module pattern does elegantly cover the bases that namespaces used to cover, but it also promotes additional good practices. First, it promotes usage of self-contained, single responsibility units of code through the closure-based, stricter scoping mechanism. Namespaces are somewhat more porous, as using/import statements can be used bi-directionally, which leads us to my second point… Sane dependency graphs are easier to achieve and sustain with such a structure. With namespaces, it is easy to construct dependency cycles (that’s bad, mmkay?). With this pattern, the equivalent would be to build mega-components, which are an easier problem to spot than a decay into inter-dependent namespaces, for which you need specialized tools. I really like this pattern very much, and I would like to see more environments implement it. One could argue that dependency injection has some commonalities with this for example. What do you think? This is the half-baked result of some morning shower reflections, and I’d love to read your thoughts about it. What am I missing?

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Oracle NoSQL Database Exceeds 1 Million Mixed YCSB Ops/Sec

- by Charles Lamb

We ran a set of YCSB performance tests on Oracle NoSQL Database using SSD cards and Intel Xeon E5-2690 CPUs with the goal of achieving 1M mixed ops/sec on a 95% read / 5% update workload. We used the standard YCSB parameters: 13 byte keys and 1KB data size (1,102 bytes after serialization). The maximum database size was 2 billion records, or approximately 2 TB of data. We sized the shards to ensure that this was not an "in-memory" test (i.e. the data portion of the B-Trees did not fit into memory). All updates were durable and used the "simple majority" replica ack policy, effectively 'committing to the network'. All read operations used the Consistency.NONE_REQUIRED parameter allowing reads to be performed on any replica. In the past we have achieved 100K ops/sec using SSD cards on a single shard cluster (replication factor 3) so for this test we used 10 shards on 15 Storage Nodes with each SN carrying 2 Rep Nodes and each RN assigned to its own SSD card. After correcting a scaling problem in YCSB, we blew past the 1M ops/sec mark with 8 shards and proceeded to hit 1.2M ops/sec with 10 shards. Hardware Configuration We used 15 servers, each configured with two 335 GB SSD cards. We did not have homogeneous CPUs across all 15 servers available to us so 12 of the 15 were Xeon E5-2690, 2.9 GHz, 2 sockets, 32 threads, 193 GB RAM, and the other 3 were Xeon E5-2680, 2.7 GHz, 2 sockets, 32 threads, 193 GB RAM. There might have been some upside in having all 15 machines configured with the faster CPU, but since CPU was not the limiting factor we don't believe the improvement would be significant. The client machines were Xeon X5670, 2.93 GHz, 2 sockets, 24 threads, 96 GB RAM. Although the clients had 96 GB of RAM, neither the NoSQL Database or YCSB clients require anywhere near that amount of memory and the test could have just easily been run with much less. Networking was all 10GigE. YCSB Scaling Problem We made three modifications to the YCSB benchmark. The first was to allow the test to accommodate more than 2 billion records (effectively int's vs long's). To keep the key size constant, we changed the code to use base 32 for the user ids. The second change involved to the way we run the YCSB client in order to make the test itself horizontally scalable.The basic problem has to do with the way the YCSB test creates its Zipfian distribution of keys which is intended to model "real" loads by generating clusters of key collisions. Unfortunately, the percentage of collisions on the most contentious keys remains the same even as the number of keys in the database increases. As we scale up the load, the number of collisions on those keys increases as well, eventually exceeding the capacity of the single server used for a given key.This is not a workload that is realistic or amenable to horizontal scaling. YCSB does provide alternate key distribution algorithms so this is not a shortcoming of YCSB in general. We decided that a better model would be for the key collisions to be limited to a given YCSB client process. That way, as additional YCSB client processes (i.e. additional load) are added, they each maintain the same number of collisions they encounter themselves, but do not increase the number of collisions on a single key in the entire store. We added client processes proportionally to the number of records in the database (and therefore the number of shards). This change to the use of YCSB better models a use case where new groups of users are likely to access either just their own entries, or entries within their own subgroups, rather than all users showing the same interest in a single global collection of keys. If an application finds every user having the same likelihood of wanting to modify a single global key, that application has no real hope of getting horizontal scaling. Finally, we used read/modify/write (also known as "Compare And Set") style updates during the mixed phase. This uses versioned operations to make sure that no updates are lost. This mode of operation provides better application behavior than the way we have typically run YCSB in the past, and is only practical at scale because we eliminated the shared key collision hotspots.It is also a more realistic testing scenario. To reiterate, all updates used a simple majority replica ack policy making them durable. Scalability Results In the table below, the "KVS Size" column is the number of records with the number of shards and the replication factor. Hence, the first row indicates 400m total records in the NoSQL Database (KV Store), 2 shards, and a replication factor of 3. The "Clients" column indicates the number of YCSB client processes. "Threads" is the number of threads per process with the total number of threads. Hence, 90 threads per YCSB process for a total of 360 threads. The client processes were distributed across 10 client machines. Shards KVS Size Clients Mixed (records) Threads OverallThroughput(ops/sec) Read Latencyav/95%/99%(ms) Write Latencyav/95%/99%(ms) 2 400m(2x3) 4 90(360) 302,152 0.76/1/3 3.08/8/35 4 800m(4x3) 8 90(720) 558,569 0.79/1/4 3.82/16/45 8 1600m(8x3) 16 90(1440) 1,028,868 0.85/2/5 4.29/21/51 10 2000m(10x3) 20 90(1800) 1,244,550 0.88/2/6 4.47/23/53

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Atheros AR2413 wireless not working after shutdown

- by Chandrasekhar

I am using a Ubuntu 11.04 on an Acer aspire 3680 laptop and my wifi is not working. I followed the below commands to install the madwifi driver: sudo su apt-get install subversion cd /usr/src svn checkout http://madwifi-project.org/svn/madwifi/trunk madwifi tar cfvz madwifi.tgz cd madwifi make && make install echo "blacklist ath5k" /etc/modprobe.d/blacklist.conf echo "ath_pci" /etc/modules modprobe ath_pci sudo reboot After installation I am facing the same problem. My wifi wont work after I shutdown. Infact it didn't work after suspend but I rectified that problem by the following commands: Command 1: sudo rmmod -f ath_pci sudo rfkill unblock all sudo modprobe ath_pci along with the command SUSPEND_MODULES=ath_pci added to the /etc/pm/config.d/madwifi directory. So if I suspend and then on my laptop the wifi loads well and doesn't create a problem. But if I shutdown my laptop the wifi never loads again and eachtime I have to run a Ubuntu 9.04 live CD to load it. I did try adding the Command 1 to the /etc/rc.local directory but still it doesn't work. So my question is: What should I do in order to make my wireless work without having to run a live CD of ubuntu 9.04 everytime after shutdown? Thanks. Here are the outputs which one might need: Output 1 chandru@chandru-acer:~$ lspci 00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03) 00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03) 00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03) 00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 02) 00:1c.0 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 1 (rev 02) 00:1c.1 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 2 (rev 02) 00:1c.2 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 3 (rev 02) 00:1d.0 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 (rev 02) 00:1d.1 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 (rev 02) 00:1d.2 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 (rev 02) 00:1d.3 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 (rev 02) 00:1d.7 USB Controller: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller (rev 02) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e2) 00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 02) 00:1f.2 IDE interface: Intel Corporation 82801GBM/GHM (ICH7 Family) SATA IDE Controller (rev 02) 00:1f.3 SMBus: Intel Corporation N10/ICH 7 Family SMBus Controller (rev 02) 02:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8038 PCI-E Fast Ethernet Controller (rev 14) 0a:03.0 Ethernet controller: Atheros Communications Inc. AR2413 802.11bg NIC (rev 01) 0a:09.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller 0a:09.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD) Output 2: lsmod Module Size Used by wlan_tkip 17074 2 binfmt_misc 13213 1 parport_pc 32111 0 ppdev 12849 0 snd_hda_codec_si3054 12924 1 snd_hda_codec_realtek 255882 1 joydev 17322 0 snd_atiixp_modem 18624 0 snd_via82xx_modem 18305 0 snd_intel8x0m 18493 0 snd_ac97_codec 105614 3 snd_atiixp_modem,snd_via82xx_modem,snd_intel8x0m snd_hda_intel 24113 2 ac97_bus 12642 1 snd_ac97_codec snd_hda_codec 90901 3 snd_hda_codec_si3054,snd_hda_codec_realtek,snd_hda_intel i915 451053 3 snd_hwdep 13274 1 snd_hda_codec snd_pcm 80042 7 snd_hda_codec_si3054,snd_atiixp_modem,snd_via82xx_modem,snd_intel8x0m,snd_ac97_codec,snd_hda_intel,snd_hda_codec snd_seq_midi 13132 0 snd_rawmidi 25269 1 snd_seq_midi drm_kms_helper 40971 1 i915 snd_seq_midi_event 14475 1 snd_seq_midi snd_seq 51291 2 snd_seq_midi,snd_seq_midi_event pcmcia 39671 0 snd_timer 28659 2 snd_pcm,snd_seq snd_seq_device 14110 3 snd_seq_midi,snd_rawmidi,snd_seq drm 184164 4 i915,drm_kms_helper yenta_socket 27230 0 tifm_7xx1 12898 0 wlan_scan_sta 21945 1 ath_rate_sample 17279 1 pcmcia_rsrc 18292 1 yenta_socket psmouse 73312 0 tifm_core 15040 1 tifm_7xx1 snd 55295 18 snd_hda_codec_si3054,snd_hda_codec_realtek,snd_atiixp_modem,snd_via82xx_modem,snd_intel8x0m,snd_ac97_codec,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device serio_raw 12990 0 i2c_algo_bit 13184 1 i915 soundcore 12600 1 snd pcmcia_core 21505 3 pcmcia,yenta_socket,pcmcia_rsrc video 19112 1 i915 ath_pci 183044 0 snd_page_alloc 14073 5 snd_atiixp_modem,snd_via82xx_modem,snd_intel8x0m,snd_hda_intel,snd_pcm wlan 224640 5 wlan_tkip,wlan_scan_sta,ath_rate_sample,ath_pci ath_hal 398701 3 ath_rate_sample,ath_pci lp 13349 0 parport 36746 3 parport_pc,ppdev,lp usbhid 41704 0 hid 77084 1 usbhid sky2 49172 0 Output 3 root@chandru-acer:~# lshw -C network PCI (sysfs) *-network description: Ethernet interface product: 88E8038 PCI-E Fast Ethernet Controller vendor: Marvell Technology Group Ltd. physical id: 0 bus info: pci@0000:02:00.0 logical name: eth0 version: 14 serial: 00:16:36:fb:aa:64 capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.28 firmware=N/A latency=0 link=no multicast=yes port=twisted pair resources: irq:43 memory:44000000-44003fff ioport:2000(size=256) *-network description: Wireless interface product: AR2413 802.11bg NIC vendor: Atheros Communications Inc. physical id: 3 bus info: pci@0000:0a:03.0 logical name: wifi0 version: 01 serial: 00:19:7d:d3:0c:fd width: 32 bits clock: 33MHz capabilities: pm bus_master cap_list logical ethernet physical wireless configuration: broadcast=yes driver=ath_pci ip=192.168.1.6 latency=96 maxlatency=28 mingnt=10 multicast=yes wireless=IEEE 802.11g resources: irq:18 memory:d0000000-d000ffff Output 4 root@chandru-acer:~# lsmod | grep ath_pci ath_pci 183044 0 wlan 224640 5 wlan_tkip,wlan_scan_sta,ath_rate_sample,ath_pci ath_hal 398701 3 ath_rate_sample,ath_pci

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JPRT: A Build & Test System

- by kto

DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -kto

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Collision Detection problems in Voxel Engine (XNA)

- by Darestium

I am creating a minecraft like terrain engine in XNA and have had some collision problems for quite some time. I have checked and changed my code based on other peoples collision code and I still have the same problem. It always seems to be off by about a block. for instance, if I walk across a bridge which is one block high I fall through it. Also, if you walk towards a "row" of blocks like this: You are able to stand "inside" the left most one, and you collide with nothing in the right most side (where there is no block and is not visible on this image). Here is all my collision code: private void Move(GameTime gameTime, Vector3 direction) { float speed = playermovespeed * (float)gameTime.ElapsedGameTime.TotalSeconds; Matrix rotationMatrix = Matrix.CreateRotationY(player.Camera.LeftRightRotation); Vector3 rotatedVector = Vector3.Transform(direction, rotationMatrix); rotatedVector.Normalize(); Vector3 testVector = rotatedVector; testVector.Normalize(); Vector3 movePosition = player.position + testVector * speed; Vector3 midBodyPoint = movePosition + new Vector3(0, -0.7f, 0); Vector3 headPosition = movePosition + new Vector3(0, 0.1f, 0); if (!world.GetBlock(movePosition).IsSolid && !world.GetBlock(midBodyPoint).IsSolid && !world.GetBlock(headPosition).IsSolid) { player.position += rotatedVector * speed; } //player.position += rotatedVector * speed; } ... public void UpdatePosition(GameTime gameTime) { player.velocity.Y += playergravity * (float)gameTime.ElapsedGameTime.TotalSeconds; Vector3 footPosition = player.Position + new Vector3(0f, -1.5f, 0f); Vector3 headPosition = player.Position + new Vector3(0f, 0.1f, 0f); // If the block below the player is solid the Y velocity should be zero if (world.GetBlock(footPosition).IsSolid || world.GetBlock(headPosition).IsSolid) { player.velocity.Y = 0; } UpdateJump(gameTime); UpdateCounter(gameTime); ProcessInput(gameTime); player.Position = player.Position + player.velocity * (float)gameTime.ElapsedGameTime.TotalSeconds; velocity = Vector3.Zero; } and the one and only function in the camera class: protected void CalculateView() { Matrix rotationMatrix = Matrix.CreateRotationX(upDownRotation) * Matrix.CreateRotationY(leftRightRotation); lookVector = Vector3.Transform(Vector3.Forward, rotationMatrix); cameraFinalTarget = Position + lookVector; Vector3 cameraRotatedUpVector = Vector3.Transform(Vector3.Up, rotationMatrix); viewMatrix = Matrix.CreateLookAt(Position, cameraFinalTarget, cameraRotatedUpVector); } which is called when the rotation variables are changed: public float LeftRightRotation { get { return leftRightRotation; } set { leftRightRotation = value; CalculateView(); } } public float UpDownRotation { get { return upDownRotation; } set { upDownRotation = value; CalculateView(); } } World class: public Block GetBlock(int x, int y, int z) { if (InBounds(x, y, z)) { Vector3i regionalPosition = GetRegionalPosition(x, y, z); Vector3i region = GetRegionPosition(x, y, z); return regions[region.X, region.Y, region.Z].Blocks[regionalPosition.X, regionalPosition.Y, regionalPosition.Z]; } return new Block(BlockType.none); } public Vector3i GetRegionPosition(int x, int y, int z) { int regionx = x == 0 ? 0 : x / Variables.REGION_SIZE_X; int regiony = y == 0 ? 0 : y / Variables.REGION_SIZE_Y; int regionz = z == 0 ? 0 : z / Variables.REGION_SIZE_Z; return new Vector3i(regionx, regiony, regionz); } public Vector3i GetRegionalPosition(int x, int y, int z) { int regionx = x == 0 ? 0 : x / Variables.REGION_SIZE_X; int X = x % Variables.REGION_SIZE_X; int regiony = y == 0 ? 0 : y / Variables.REGION_SIZE_Y; int Y = y % Variables.REGION_SIZE_Y; int regionz = z == 0 ? 0 : z / Variables.REGION_SIZE_Z; int Z = z % Variables.REGION_SIZE_Z; return new Vector3i(X, Y, Z); } Any ideas how to fix this problem? EDIT 1: Graphic of the problem: EDIT 2 GetBlock, Vector3 version: public Block GetBlock(Vector3 position) { int x = (int)Math.Floor(position.X); int y = (int)Math.Floor(position.Y); int z = (int)Math.Ceiling(position.Z); Block block = GetBlock(x, y, z); return block; } Now, the thing is I tested the theroy that the Z is always "off by one" and by ceiling the value it actually works as intended. Altough it still could be greatly more accurate (when you go down holes you can see through the sides, and I doubt it will work with negitive positions). I also does not feel clean Flooring the X and Y values and just Ceiling the Z. I am surely not doing something correctly still.

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Avoiding coupling

- by Seralize

It is also true that a system may become so coupled, where each class is dependent on other classes that depend on other classes, that it is no longer possible to make a change in one place without having a ripple effect and having to make subsequent changes in many places.[1] This is why using an interface or an abstract class can be valuable in any object-oriented software project. Quote from Wikipedia Starting from scratch I'm starting from scratch with a project that I recently finished because I found the code to be too tightly coupled and hard to refactor, even when using MVC. I will be using MVC on my new project aswell but want to try and avoid the pitfalls this time, hopefully with your help. Project summary My issue is that I really wish to keep the Controller as clean as possible, but it seems like I can't do this. The basic idea of the program is that the user picks wordlists which is sent to the game engine. It will pick random words from the lists until there are none left. Problem at hand My main problem is that the game will have 'modes', and need to check the input in different ways through a method called checkWord(), but exactly where to put this and how to abstract it properly is a challenge to me. I'm new to design patterns, so not sure whether there exist any might fit my problem. My own attempt at abstraction Here is what I've gotten so far after hours of 'refactoring' the design plans, and I know it's long, but it's the best I could do to try and give you an overview (Note: As this is the sketch, anything is subject to change, all help and advice is very welcome. Also note the marked coupling points): Wordlist class Wordlist { // Basic CRUD etc. here! // Other sample methods: public function wordlistCount($user_id) {} // Returns count of how many wordlists a user has public function getAll($user_id) {} // Returns all wordlists of a user } Word class Word { // Basic CRUD etc. here! // Other sample methods: public function wordCount($wordlist_id) {} // Returns count of words in a wordlist public function getAll($wordlist_id) {} // Returns all words from a wordlist public function getWordInfo($word_id) {} // Returns information about a word } Wordpicker class Wordpicker { // The class needs to know which words and wordlists to exclude protected $_used_words = array(); protected $_used_wordlists = array(); // Wordlists to pick words from protected $_wordlists = array(); /* Public Methods */ public function setWordlists($wordlists = array()) {} public function setUsedWords($used_words = array()) {} public function setUsedWordlists($used_wordlists = array()) {} public function getRandomWord() {} // COUPLING POINT! Will most likely need to communicate with both the Wordlist and Word classes /* Protected Methods */ protected function _checkAvailableWordlists() {} // COUPLING POINT! Might need to check if wordlists are deleted etc. protected function _checkAvailableWords() {} // COUPLING POINT! Method needs to get all words in a wordlist from the Word class } Game class Game { protected $_session_id; // The ID of a game session which gets stored in the database along with game details protected $_game_info = array(); // Game instantiation public function __construct($user_id) { if (! $this->_session_id = $this->_gameExists($user_id)) { // New game } else { // Resume game } } // This is the method I tried to make flexible by using abstract classes etc. // Does it even belong in this class at all? public function checkWord($answer, $native_word, $translation) {} // This method checks the answer against the native word / translation word, depending on game mode public function getGameInfo() {} // Returns information about a game session, or creates it if it does not exist public function deleteSession($session_id) {} // Deletes a game session from the database // Methods dealing with game session information protected function _gameExists($user_id) {} protected function _getProgress($session_id) {} protected function _updateProgress($game_info = array()) {} } The Game /* CONTROLLER */ /* "Guess the word" page */ // User input $game_type = $_POST['game_type']; // Chosen with radio buttons etc. $wordlists = $_POST['wordlists']; // Chosen with checkboxes etc. // Starts a new game or resumes one from the database $game = new Game($_SESSION['user_id']); $game_info = $game->getGameInfo(); // Instantiates a new Wordpicker $wordpicker = new Wordpicker(); $wordpicker->setWordlists((isset($game_info['wordlists'])) ? $game_info['wordlists'] : $wordlists); $wordpicker->setUsedWordlists((isset($game_info['used_wordlists'])) ? $game_info['used_wordlists'] : NULL); $wordpicker->setUsedWords((isset($game_info['used_words'])) ? $game_info['used_words'] : NULL); // Fetches an available word if (! $word_id = $wordpicker->getRandomWord()) { // No more words left - game over! $game->deleteSession($game_info['id']); redirect(); } else { // Presents word details to the user $word = new Word(); $word_info = $word->getWordInfo($word_id); } The Bit to Finish /* CONTROLLER */ /* "Check the answer" page */ // ?????????????????? ( http://pastebin.com/cc6MtLTR ) Make sure you toggle the 'Layout Width' to the right for a better view. Thanks in advance. Questions To which extent should objects be loosely coupled? If object A needs info from object B, how is it supposed to get this without losing too much cohesion? As suggested in the comments, models should hold all business logic. However, as objects should be independent, where to glue them together? Should the model contain some sort of "index" or "client" area which connects the dots? Edit: So basically what I should do for a start is to make a new model which I can more easily call with oneliners such as $model->doAction(); // Lots of code in here which uses classes! How about the method for checking words? Should it be it's own object? I'm not sure where I should put it as it's pretty much part of the 'game'. But on another hand, I could just leave out the 'abstraction and OOPness' and make it a method of the 'client model' which will be encapsulated from the controller anyway. Very unsure about this.

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"Guiding" a Domain Expert to Retire from Programming

- by James Kolpack

I've got a friend who does IT at a local non-profit where they're using a custom web application which is no longer supported by the company who built it. (out of business, support was too expensive, I'm not sure...) Development on this app started around 10+ years ago so the technologies being harnessed are pretty out of date now - classic asp using vbscript and SQL Server 2000. The application domain is in the realm of government bookkeeping - so even though the development team is long gone, there are often new requirements of this software. Enter the... The domain expert. This is an middle aged accounting whiz without much (or any?) prior development experience. He studied the pages, code and queries and learned how to ape the style of the original team which, believe me, is mediocre at best. He's very clever and very tenacious but has no experience in software beyond what he's picked up from this app. Otherwise, he's a pleasant guy to talk to and definitely knows his domain. My friend in IT, and probably his superiors in the company, want him out of the code. They view him as wasting his expertise on coding tasks he shouldn't be doing. My friend got me involved with a few small contracts which I handled without much problem - other than somewhat of a communication barrier with the domain expert. He explained the requirements very quickly, assuming prior knowledge of the domain which I do not have. This is partially his normal style, and I think maybe a bit of resentment from my involvement. So, I think he feels like the owner of the code and has entrenched himself in a development position. So... his coding technique. One of his latest endeavors was to make a page that only he could reach (theoretically - the security model for the system is wretched) where he can enter a raw SQL query, run it, and save the query to run again later. A report that I worked on had been originally implemented by him using 6 distinct queries, 3 or 4 temp tables to coordinate the data between the queries, and the final result obtained by importing the data from the final query into Access and doing a pivot and some formatting. It worked - well, some of the results were incorrect - but at what a cost! (I implemented the report in a single query with at least 1/10th the amount of code.) He edits code in notepad. He doesn't seem to know about online reference material for the languages. I recently read an article on Dr. Dobbs titled "What Makes Bad Programmers Different" - and instantly thought of our domain expert. From the article: Their code is large, messy, and bug laden. They have very superficial knowledge of their problem domain and their tools. Their code has a lot of copy/paste and they have very little interest in techniques that reduce it. The fail to account for edge cases, while inefficiently dealing with the general case. They never have time to comment their code or break it into smaller pieces. Empirical evidence plays no little role in their decisions. 5.5 out of 6. My friend is wanting me to argue the case to their management - specifically, I got this email from their manager to respond to: ...Also, I need to talk to you about what effect there is from Domain Expert continuing to make edits to the live environment. If that is a problem for you I need to know so I can have his access blocked. Some examples would help. In my opinion, from a technical standpoint, it's dangerous to have him making changes without any oversight. On the other hand, I'm just doing one-off contracts at this point and don't have much desire to get involved deeply enough that I'm essentially arguing as one of the Bobs from Office Space. I'd like to help my friend out - but I feel like I'm getting in the middle of a political battle. More importantly - if I do get involved and suggest that his editing privileges be removed, it needs to be handled carefully so that doesn't feel belittled. He is beyond a doubt the foremost expert on this system. I'm hoping this is familiar territory for some other stackechangers, because I'm feeling a little bewildered. How should I respond? Should I argue that he shouldn't be allowed to touch the code? Should I phrase it as "no single developer, no matter how experienced, should be working on production code unchecked"? Should I argue to keep him involved with the code, but with a review process? Should I say "glad I could help, but uh, I'm busy now!" Other options? Thanks a bunch!

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Why won't USB 3.0 external hard drive run at USB 3.0 speeds?

- by jgottula

I recently purchased a PCI Express x1 USB 3.0 controller card (containing the NEC USB 3.0 controller) with the intent of using a USB 3.0 external hard drive with my Linux box. I installed the card in an empty PCIe slot on my motherboard, connected the card to a power cable, strung a USB 3.0 cable between one of the new ports and my external HDD, and connected the HDD to a wall socket for power. Booting the system, the drive works 100% as intended, with the one exception of throughput: rather than using SuperSpeed 4.8 Gbps connectivity, it seems to be falling back to High Speed 480 Mbps USB 2.0-style throughput. Disk Utility shows it as a 480 Mbps device, and running a couple Disk Utility and dd benchmarks confirms that the drive fails to exceed ~40 MB/s (the approximate limit of USB 2.0), despite it being an SSD capable of far more than that. When I connect my USB 3.0 HDD, dmesg shows this: [ 3923.280018] usb 3-2: new high speed USB device using ehci_hcd and address 6 where I would expect to find this: [ 3923.280018] usb 3-2: new SuperSpeed USB device using xhci_hcd and address 6 My system was running on kernel 2.6.35-25-generic at the time. Then, I stumbled upon this forum thread by an individual who found that a bug, which was present in kernels prior to 2.6.37-rc5, could be the culprit for this type of problem. Consequently, I installed the 2.6.37-generic mainline Ubuntu kernel to determine if the problem would go away. It didn't, so I tried 2.6.38-rc3-generic, and even the 2.6.38 nightly from 2010.02.01, to no avail. In short, I'm trying to determine why, with USB 3.0 support in the kernel, my USB 3.0 drive fails to run at full SuperSpeed throughput. See the comments under this question for additional details. Output that might be relevant to the problem (when booting from 2.6.38-rc3): Relevant lines from dmesg: [ 19.589491] xhci_hcd 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17 [ 19.589512] xhci_hcd 0000:03:00.0: setting latency timer to 64 [ 19.589516] xhci_hcd 0000:03:00.0: xHCI Host Controller [ 19.589623] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 12 [ 19.650492] xhci_hcd 0000:03:00.0: irq 17, io mem 0xf8100000 [ 19.650556] xhci_hcd 0000:03:00.0: irq 47 for MSI/MSI-X [ 19.650560] xhci_hcd 0000:03:00.0: irq 48 for MSI/MSI-X [ 19.650563] xhci_hcd 0000:03:00.0: irq 49 for MSI/MSI-X [ 19.653946] xHCI xhci_add_endpoint called for root hub [ 19.653948] xHCI xhci_check_bandwidth called for root hub Relevant section of sudo lspci -v: 03:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03) (prog-if 30) Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at f8100000 (64-bit, non-prefetchable) [size=8K] Capabilities: [50] Power Management version 3 Capabilities: [70] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [90] MSI-X: Enable+ Count=8 Masked- Capabilities: [a0] Express Endpoint, MSI 00 Capabilities: [100] Advanced Error Reporting Capabilities: [140] Device Serial Number ff-ff-ff-ff-ff-ff-ff-ff Capabilities: [150] #18 Kernel driver in use: xhci_hcd Kernel modules: xhci-hcd Relevant section of sudo lsusb -v: Bus 012 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.00 bDeviceClass 9 Hub bDeviceSubClass 0 Unused bDeviceProtocol 3 bMaxPacketSize0 9 idVendor 0x1d6b Linux Foundation idProduct 0x0003 3.0 root hub bcdDevice 2.06 iManufacturer 3 Linux 2.6.38-020638rc3-generic xhci_hcd iProduct 2 xHCI Host Controller iSerial 1 0000:03:00.0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 25 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xe0 Self Powered Remote Wakeup MaxPower 0mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 9 Hub bInterfaceSubClass 0 Unused bInterfaceProtocol 0 Full speed (or root) hub iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0004 1x 4 bytes bInterval 12 Hub Descriptor: bLength 9 bDescriptorType 41 nNbrPorts 4 wHubCharacteristic 0x0009 Per-port power switching Per-port overcurrent protection TT think time 8 FS bits bPwrOn2PwrGood 10 * 2 milli seconds bHubContrCurrent 0 milli Ampere DeviceRemovable 0x00 PortPwrCtrlMask 0xff Hub Port Status: Port 1: 0000.0100 power Port 2: 0000.0100 power Port 3: 0000.0100 power Port 4: 0000.0100 power Device Status: 0x0003 Self Powered Remote Wakeup Enabled Full, non-verbose lsusb: Bus 012 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 011 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 010 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 009 Device 003: ID 04d9:0702 Holtek Semiconductor, Inc. Bus 009 Device 002: ID 046d:c068 Logitech, Inc. G500 Laser Mouse Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 006: ID 174c:5106 ASMedia Technology Inc. Bus 003 Device 004: ID 0bda:0151 Realtek Semiconductor Corp. Mass Storage Device (Multicard Reader) Bus 003 Device 002: ID 058f:6366 Alcor Micro Corp. Multi Flash Reader Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 006: ID 1687:0163 Kingmax Digital Inc. Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 046d:081b Logitech, Inc. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Full output: full dmesg full lspci full lsusb

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Implementing a Custom Coherence PartitionAssignmentStrategy

- by jpurdy

A recent A-Team engagement required the development of a custom PartitionAssignmentStrategy (PAS). By way of background, a PAS is an implementation of a Java interface that controls how a Coherence partitioned cache service assigns partitions (primary and backup copies) across the available set of storage-enabled members. While seemingly straightforward, this is actually a very difficult problem to solve. Traditionally, Coherence used a distributed algorithm spread across the cache servers (and as of Coherence 3.7, this is still the default implementation). With the introduction of the PAS interface, the model of operation was changed so that the logic would run solely in the cache service senior member. Obviously, this makes the development of a custom PAS vastly less complex, and in practice does not introduce a significant single point of failure/bottleneck. Note that Coherence ships with a default PAS implementation but it is not used by default. Further, custom PAS implementations are uncommon (this engagement was the first custom implementation that we know of). The particular implementation mentioned above also faced challenges related to managing multiple backup copies but that won't be discussed here. There were a few challenges that arose during design and implementation: Naive algorithms had an unreasonable upper bound of computational cost. There was significant complexity associated with configurations where the member count varied significantly between physical machines. Most of the complexity of a PAS is related to rebalancing, not initial assignment (which is usually fairly simple). A custom PAS may need to solve several problems simultaneously, such as: Ensuring that each member has a similar number of primary and backup partitions (e.g. each member has the same number of primary and backup partitions) Ensuring that each member carries similar responsibility (e.g. the most heavily loaded member has no more than one partition more than the least loaded). Ensuring that each partition is on the same member as a corresponding local resource (e.g. for applications that use partitioning across message queues, to ensure that each partition is collocated with its corresponding message queue). Ensuring that a given member holds no more than a given number of partitions (e.g. no member has more than 10 partitions) Ensuring that backups are placed far enough away from the primaries (e.g. on a different physical machine or a different blade enclosure) Achieving the above goals while ensuring that partition movement is minimized. These objectives can be even more complicated when the topology of the cluster is irregular. For example, if multiple cluster members may exist on each physical machine, then clearly the possibility exists that at certain points (e.g. following a member failure), the number of members on each machine may vary, in certain cases significantly so. Consider the case where there are three physical machines, with 3, 3 and 9 members each (respectively). This introduces complexity since the backups for the 9 members on the the largest machine must be spread across the other 6 members (to ensure placement on different physical machines), preventing an even distribution. For any given problem like this, there are usually reasonable compromises available, but the key point is that objectives may conflict under extreme (but not at all unlikely) circumstances. The most obvious general purpose partition assignment algorithm (possibly the only general purpose one) is to define a scoring function for a given mapping of partitions to members, and then apply that function to each possible permutation, selecting the most optimal permutation. This would result in N! (factorial) evaluations of the scoring function. This is clearly impractical for all but the smallest values of N (e.g. a partition count in the single digits). It's difficult to prove that more efficient general purpose algorithms don't exist, but the key take away from this is that algorithms will tend to either have exorbitant worst case performance or may fail to find optimal solutions (or both) -- it is very important to be able to show that worst case performance is acceptable. This quickly leads to the conclusion that the problem must be further constrained, perhaps by limiting functionality or by using domain-specific optimizations. Unfortunately, it can be very difficult to design these more focused algorithms. In the specific case mentioned, we constrained the solution space to very small clusters (in terms of machine count) with small partition counts and supported exactly two backup copies, and accepted the fact that partition movement could potentially be significant (preferring to solve that issue through brute force). We then used the out-of-the-box PAS implementation as a fallback, delegating to it for configurations that were not supported by our algorithm. Our experience was that the PAS interface is quite usable, but there are intrinsic challenges to designing PAS implementations that should be very carefully evaluated before committing to that approach.

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