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• Make Language change specific to window/app not whole system (Windows 8.1)

  - by Boppity Bop

  I have Windows 8.1 Pro English. Sometime I need to use another languages (I did not install any language packs and my locale is English). So I have a few keyboards enabled. However in W7 when I switch keyboard it stays in the window I switched it.. and other windows have English at the same time... In windows 8.1 if I switch keyboard it changes everywhere. is there an option to keep different keyboards in different windows / apps ?

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• How can I change my language/keyboard input language system-wide temporarily?

  - by Adam Lynch

  I currently have two languages set up; English and Dutch. The only difference is in keyboard input. The Dutch one uses the French/Belgian AZERTY layout and the English one uses the Irish/English QWERTY layout (@ = Shift+'). When a Belgian colleague needs to use my computer, I switch the language to NL (Dutch) (therefore the input to AZERTY) using the language bar, but it seems to be application-specific. (I.e: After changing the input to AZERTY for my colleague, if he then clicks on another program it switches back to QWERTY for that program). Is there a way I can quickly switch between the two comprehensively yet temporarily?

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• how to change some of the numbers in word to be arabic numbers without changing a global setting in windows?

  - by Karim

  i have a word document. it have 2 parts one english and one arabic. the problem is that all the numbers are english numbers [0123456789] but i want the arabic part's numbers to be arabic numbers [??????????] how can i do that in word 2007 or 2010? thanks Edit: since i didnt receive any response to the question i created a software that converts english numbers to arabic and then i use it to convert the numbers in the document. but still wondering if there is a more easy way to do it?

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• Google Chrome is in Danish

  - by Mad Cow

  I'm not sure what i have done, but by default, Chrome comes up in Danish. I can ignore this most of the time but its v annoying and i cant seem to change it. For example google directions come up in Danish too and have to be translated back to English! I have tried the spanner icon, and i've confirmed the only two languages specified are En and US English. Does anyone have any ideas how i can default it back to English all the time. In-lined the original screenshot from www.cow-shed.co.uk Thanks

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• Language bar switched input types on me.

  - by Elijah

  I learned Japanese, but I'm not native to Japan, so I never had a Japanese keyboard. I used to use the language bar to go back and forth between English and Japanese, simply typing the words in romaji and having windows convert it into either hiragana, katakana and sometimes Kanji. Suddenly, my input type changes. I am no longer able to simply type in English, it changed my keyboard into a native Japanese keyboard, and what's worse it doesn't even allow me to write in hiragana, which I would need way more than katakana. Can anyone tell me how to restore it to the old setting where I simply chose what the output dialect would be, and typed the words phonetically in english and have it translate the sounds for me into japanese characters?

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• How to modify existing keyboard layout (RU, kbdru.dll)?

  - by Anton

  There's a program I'm thinking of using called Punto Switcher that detects a language I'm typing in and switching entire word between Russian and English. The problem I have with this setup is that even though most of Russian letters "correspond" to English letters, Russian keys are scattered all over the keyboard and I don't feel like learning them all as I type in English mostly. Now, the program is very specific about me using RU, kbdru.dll file, not any other and if I use a custom keyboard under Russian, it doesn't recognize what I type so I think I should change the default RU keyboard. I created my custom keyboard using Microsoft's tool and I need to modify original one. I think it will take more than just replacing a file. Help?

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• Keyboard that can't be removed (W8 CP)

  - by torazaburo

  Somehow I ended up with four keyboards installed (English (United States), Japanese (Japan), Kannada, and Hindi. They are installed in the sense that the tray drop down displays these four, and when I ALT-SHIFT through my keyboards it cycles through them. The mysterious thing is that in the Languages Control Panel, only the first two are shown, so I am stuck as to how to remove the last two. In the past, I may have installed and removed the Kannada and Hindi keyboards. What I did recently was to install the English (India) keyboard, as a way to get the ability to input the rupee symbol with ALT-CTRL-4. That English (India) keyboard did show up in the Languages Control Panel and allow itself to be removed. It almost seems like installing that keyboard somehow activate hidden registry settings left over from back when I had Kannada and Hindi installed. In any case, any ideas about how to remove these keyboards which don't appear in the Language Control Panel?

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• Make interchangeable class types via pointer casting only, without having to allocate any new objects?

  - by HostileFork

  UPDATE: I do appreciate "don't want that, want this instead" suggestions. They are useful, especially when provided in context of the motivating scenario. Still...regardless of goodness/badness, I've become curious to find a hard-and-fast "yes that can be done legally in C++11" vs "no it is not possible to do something like that". I want to "alias" an object pointer as another type, for the sole purpose of adding some helper methods. The alias cannot add data members to the underlying class (in fact, the more I can prevent that from happening the better!) All aliases are equally applicable to any object of this type...it's just helpful if the type system can hint which alias is likely the most appropriate. There should be no information about any specific alias that is ever encoded in the underlying object. Hence, I feel like you should be able to "cheat" the type system and just let it be an annotation...checked at compile time, but ultimately irrelevant to the runtime casting. Something along these lines: Node<AccessorFoo>* fooPtr = Node<AccessorFoo>::createViaFactory(); Node<AccessorBar>* barPtr = reinterpret_cast< Node<AccessorBar>* >(fooPtr); Under the hood, the factory method is actually making a NodeBase class, and then using a similar reinterpret_cast to return it as a Node<AccessorFoo>*. The easy way to avoid this is to make these lightweight classes that wrap nodes and are passed around by value. Thus you don't need casting, just Accessor classes that take the node handle to wrap in their constructor: AccessorFoo foo (NodeBase::createViaFactory()); AccessorBar bar (foo.getNode()); But if I don't have to pay for all that, I don't want to. That would involve--for instance--making a special accessor type for each sort of wrapped pointer (AccessorFooShared, AccessorFooUnique, AccessorFooWeak, etc.) Having these typed pointers being aliased for one single pointer-based object identity is preferable, and provides a nice orthogonality. So back to that original question: Node<AccessorFoo>* fooPtr = Node<AccessorFoo>::createViaFactory(); Node<AccessorBar>* barPtr = reinterpret_cast< Node<AccessorBar>* >(fooPtr); Seems like there would be some way to do this that might be ugly but not "break the rules". According to ISO14882:2011(e) 5.2.10-7: An object pointer can be explicitly converted to an object pointer of a different type.70 When a prvalue v of type "pointer to T1" is converted to the type "pointer to cv T2", the result is static_cast(static_cast(v)) if both T1 and T2 are standard-layout types (3.9) and the alignment requirements of T2 are no stricter than those of T1, or if either type is void. Converting a prvalue of type "pointer to T1" to the type "pointer to T2" (where T1 and T2 are object types and where the alignment requirements of T2 are no stricter than those of T1) and back to its original type yields the original pointer value. The result of any other such pointer conversion is unspecified. Drilling into the definition of a "standard-layout class", we find: has no non-static data members of type non-standard-layout-class (or array of such types) or reference, and has no virtual functions (10.3) and no virtual base classes (10.1), and has the same access control (clause 11) for all non-static data members, and has no non-standard-layout base classes, and either has no non-static data member in the most-derived class and at most one base class with non-static data members, or has no base classes with non-static data members, and has no base classes of the same type as the first non-static data member. Sounds like working with something like this would tie my hands a bit with no virtual methods in the accessors or the node. Yet C++11 apparently has std::is_standard_layout to keep things checked. Can this be done safely? Appears to work in gcc-4.7, but I'd like to be sure I'm not invoking undefined behavior.

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• Open Source WPF UML Design tool

  - by oazabir

  PlantUmlEditor is my new free open source UML designer project built using WPF and .NET 3.5. If you have used plantuml before, you know that you can quickly create sophisitcated UML diagrams without struggling with a designer. Especially those who use Visio to draw UML diagrams (God forbid!), you will be at heaven. This is a super fast way to get your diagrams up and ready for show. You can *write* UML diagrams in plain English, following a simple syntax and get diagrams generated on-the-fly. This editor really saves time designing UML diagrams. I have to produce quick diagrams to convey ideas quickly to Architects, Designers and Developers everyday. So, I use this tool to write some quick diagrams at the speed of coding, and the diagrams get generated on the fly. Instead of writing a long mail explaining some complex operation or some business process in English, I can quickly write it in the editor in almost plain English, and get a nice looking activity/sequence diagram generated instantly. Making major changes is also as easy as doing search-replace and copy-pasting blocks here and there. You don't get such agility in any conventional mouse-based UML designers. I have submited a full codeproject article to give you a detail walkthrough how I have built this. Please read this article and vote for me if you like it. PlantUML Editor: A fast and simple UML editor using WPF http://www.codeproject.com/KB/smart/plantumleditor.aspx You can download the project from here: http://code.google.com/p/plantumleditor/

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• Pagination, Duplicate Content, and SEO

  - by Iamtotallylost

  Please consider a list of items (forum comments, articles, shoes, doesn't matter) which are spread over multiple pages. Different sort orders are supported (by date, by popularity, by price, etc). So, an URL might look like this (I use the query style here to simplify things): /items?id=1234&page=42&sort=popularity /items?id=1234&page=5&sort=date Now, in terms of SEO, I think I should be worried about duplicate content. After all, each item appears at least as many times as there are sort orders. I've seen Matt Cutts talking about the rel=canonical link tag, but he also said that the canonical page should have very similar content. But this is not the case here because page #1 in a non-canonical sort order might have completely different items than page #1 in the canonical sort order. For a given non-canonical page, there is no clear canonical page listing all the same items, so I think rel=canonical won't help here. Then I thought about using the noindex meta tag on all pages with non-canonical sort order, and not using it on all pages with canonical sort order. However, if I use that method, what will happen with backlinks that are going to non-canonical pages -- will they still spread their page rank juice, even though the first page googlebot (or any other crawler) is going to encounter is marked as "noindex"? Can you please comment on my problem and what you think is the best solution? If you think you have a better solution, please consider that 1) I do not want to use Javascript for this, 2) I do not want all the items to be on one page. Thank you.

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• Free Certification Exams for Visual Studio 2010

  - by budugu

  Get promotional codes from herehttp://blogs.msdn.com/gerryo/archive/2010/03/17/register-for-visual-studio-2010-beta-exams.aspx You don’t have to pay anything to take these exams.  These are 100% free. If you pass the exam, you earn the certification just the same as if you took it in a non-beta environment. From Gerry O'Brien’s blog...  2) Is this a real exam? – Yes it is.  Even though the questions are not scored at the time you take the exam, they are real questions and the exam is real.  If you pass the exam, you earn the certification just the same as if you took it in a non-beta environment.  This means you don’t get a pass/fail or score immediately following the exam, but you do get notified 8 to 10 weeks later because we move slow in getting the final scoring in place.  4) What is the main difference between a beta and non-beta exam, besides cost? – The beta exam will show you questions that have not been through a final QA check.  You are that final QA check.  Non-beta exams expose you to 40 or 45 questions and you have a total of two hours to complete it.  The beta exam could expose you to as many as 125 to 150 questions and take up to four hours.   Following exams are for Asp.Net developers Exam 71-515, TS: Web Applications Development with Microsoft .NET Framework 4Exam 71-519: Pro: Designing and Developing Web Applications Using Microsoft .NET Framework 4

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• Lost in Translation

  - by antony.reynolds

  Using the Correct Character Set for the SOA Suite Database A couple of years ago I spent a wonderful week in Tel Aviv helping with the first Oracle BAM implementation in Israel.  Although everyone I interacted spoke better English than I did, the screens and data for the implementation were all in Hebrew, meaning the Hebrew alphabet.  Over the week I learnt to recognize a few Hebrew words, enough to enable me to test what we were doing.  So I knew SOA Suite worked OK with non-English and non-Latin character sets so I was suspicious recently when a customer was having data corruption of non-Latin characters.  On investigation it turned out that the data received correctly in the SOA Suite, but then it was corrupted after being stored in the database. A little investigation revealed that the customer was using the default database character set, which is “WE8ISO8859P1” which, as the name suggests only supports West European 8-bit characters.  What was happening was that when the customer had installed his SOA repository he had ignored the message that his database was not using AL32UTF as the character. After changing the character set on his database he no longer saw the corruption of non-English character data. So the moral of this story is Always install the SOA Repository in to an AL32UTF8 Database This is true for both SOA Suite 10g and 11g.  Ignore it at your peril, because you never know when you will need to support Hebrew, or Japanese or another multi-byte character set.

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• Multiline Replacement With Visual Studio

  - by Alois Kraus

  I had to remove some file headers in a bigger project which were all of the form #region File Header /*[ Compilation unit ----------------------------------------------------------       Name            : Class1.cs       Language        : C#     Creation Date   :      Description     : -----------------------------------------------------------------------------*/ /*] END */ #endregion I know that would be a cool thing to write a simple C# program use a recursive file search, read all lines skip the first n lines and write the files back to disc. But I wanted to test things first before I ruin my source files with one little typo. There comes the Visual Studio Search and Replace in Files dialog into the game. I can test my regular expression to do a multiline match with the Find button before actually breaking anything. And if something goes wrong I have the Undo button.   There is a nice blog post from Paulo Morgado online who deals with Multiline Regular expressions. The Visual Studio Regular expressions are non standard so you have to adapt your usual Regex know how to the other patterns. The pattern I cam finally up with is \#region File Header:b*(.*\n)@\#endregion The Regular expression can be read as \#region File Header Match “#region File Header” \# Escapes the # character since it is a quantifier. :b* After this none or more spaces or tabs can follow (:b stands for space or tab) (.*\n)@ Match anything across lines in a non greedy way (the @ character makes it non greedy) to prevent matching too much until the #endregion somewhere in our source file. \#endregion Match everything until “#endregion” is found I had always knew that Visual Studio can do it but I never bothered to learn the non standard Regex syntax. This is powerful and it is inside Visual Studio since 2005!

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• Duplicate content appearing for multi lingual sites

  - by Rocky Singh

  I have a site which has a default url say "http://www.blahblah.com/" (which is default in english language). In my site there is support for multi languages. I am having few links at my home page say "English" "French" "Spanish" etc. and on clicking these links user is redirected to these links: http://www.blahblah.com/en-us/ (English) http://www.blahblah.com/fr-ca/ (French) http://www.blahblah.com/spanish-culture/ (Spanish) and based on culture in the url I am showing the content accordingly to end users in their desired language. Now, this was how my site is. The issue I am getting is with SEO. I noticed Google is considering (I checked via Google web masters) my site pages as duplicate like: 1. http://www.blahblah.com/documents/ and http://www.blahblah.com/en-us/documents/ 2. http://www.blahblah.com/news/ and http://www.blahblah.com/en-us/news and similarly all the pages are considered as a duplicate content in Google webmasters tools. I am worried of this, since I think my site is getting penalized in ranking because of this. Could you drop some idea how to overcome this situation?

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• Language redirect affecting pagerank and search listing?

  - by Janoszen

  Preface We have a number of sites that use the same redirect mechanism across the board. We recently transitioned one site from non-localised to localised and detected that the Google+ integration doesn't show up on the search results any more AND the PageRank is gone from 2 to 0. How the redirect works If the UA sends a cookie (e.g. lang=en), redirect the user to /language (e.g. /en) If the UA is a bot (.*bot.*), redirect to /en If the Accept-Language header contains a usable, non-English language, redirect to /language (English is the default on many browsers in non-English regions) If there is a valid GeoIP lookup and the detected region is linked to a supported language, redirect to /language Redirect to /en We do of course on all pages have the proper markup to indicate the alternate language: <link hreflang="de" href="/de" rel="alternate" /> As far as we can tell, we follow all publicly available guidelines from Google, so we are a bit at odds if this is a bug in Google or we have done something wrong. Question Does not having content on the root URL of a domain adversely affect search engine rankings and if yes, how does one implement a proper language redirection?

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• Oracle VM Server for x86 Training Schedule

  - by Antoinette O'Sullivan

  Learn about Oracle VM Server for x86 to see how you can accelerate enterprise application deployment and simplify lifecycle management with fully integrated support from physical to virtual servers including applications. Oracle offers a 3 day course Oracle VM Administration: Oracle VM Server for x86. This course  teaches you how to: Build a virtualization platform using the Oracle VM Manager and Oracle VM Server for x86. Deploy and manage highly configurable, inter-connected virtual machines. Install and configure Oracle VM Server for x86 as well as details of network and storage configuration, pool and repository creation, and virtual machine management. You can take this course as follows: Live Virtual Class - taking the course from your own desktop accessing a live teach by top Oracle instructors and accessing extensive hands-on exercises. No travel necessary. Over 300 events are current scheduled in many timezones across the world. See the full schedule by going to the Oracle University Portal and clicking on Virtualization. In Classroom - Events scheduled include those shown below:  Location  Date  Delivery Language  Warsaw, Poland  6 August 2012  Polish  Istanbul, Turkey  10 September 2012  Turkish  Dusseldorf, Germany  6 August 2012  German  Munich, Germany  10 September 2012  German  Paris, France  17 October 2012  French  Denver, Colorado, US  30 July 2012  English  Roseville, Minnesota, US  23 July 2012  English  Sydney, Australia  3 September  English For more information on this course and these events or to search for additional events or register your interest in an additional event/location, please visit the Oracle University Portal and click on Virtualization.

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• Browser language detection & content ranking for new language on the same site.

  - by Arnaud

  I've been reading a lot about it but it's still really hard to make up my mind. My understand is that if your website provide a link to the other language, this should not be an issue for google as long as your links are clear and clean, google will be able to make his way through it. The website was orginaly in french and I added the english version and I'm just worry that english speaker will just leave if the site is not in the correct language, for the home page I just wanted to get the value from the browser and redirect it to /fr/ or /en/ for the first page. (using php this will be very easy) Could you guys have a look at it and tell me what you think about it http://tinyurl.com/bpc5bn9 I don't want to get it wrong and lost my ranking with google. Also the website has good rank on the french side and the english has been online for 2 weeks and only get few visit a day, is that because all the back link refer to /fr/ and google is cleaver enough to decide that they are 2 differantes website and the back link will have to point to /en/ to increase the ranking value? Or will take few more weeks for the website to grow? Thanks for your hep

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• iPhone c++ development / compiler on a non-Mac PC? (Windows? Linux?)

  - by Ehrann Mehdan

  According to the (in)famous iPhone Developer Program License Agreement change 3.3.1 — Applications may only use Documented APIs in the manner prescribed by Apple and must not use or call any private APIs. Applications must be originally written in Objective-C, C, C++, or JavaScript as executed by the iPhone OS WebKit engine, and only code written in C, C++, and Objective-C may compile and directly link against the Documented APIs (e.g., Applications that link to Documented APIs through an intermediary translation or compatibility layer or tool are prohibited). So it is allowed to develop iPhone apps using C++ My questions Is there a compiler / IDE for developing iPhone apps using C++? Is that compiler / IDE available on non Mac environments? (Windows? Linux?) If not, why? I mean an eclipse C++ plugin for iPhone development will be quite popular, or is there already any serious attempt to do that?

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• unnecessary vertical scrollbar in ie6

  - by tirso

  hi to all does any could help me how to remove unnecessary scroll bar in ie6. I have already put overflow-y: hidden; but still the same output. thanks in advance here is my url http://webberzsoft.com/clients/csslayouttest/template_new.php here is my css * {margin:0;padding:0;}/*for demo purposes only, use a proper reset in your final layout*/ html,body { overflow: auto; height:100%; } body { font-size:100%; background:#777; } #wrapper{ min-height:99%; width: 1240px; margin:0 auto; background: #FFFFFF; border-left:1px solid #000; border-right:1px solid #000; } #header { background:#77F; border-bottom:1px solid #000; height: 70px; } #content{/*just to create top padding without tampering with min-height:100% on #inner*/ padding:10px 0; overflow:hidden;/*contain floats*/ } #left-index { float:left; width:220px; } #right-index { float:right; width:180px; } #middle-index { float:left; width:840px; overflow:hidden;/*contain floats*/ } #left-home { float:left; width:300px; } #right-home { float:right; width:940px; } here is my html <div id="wrapper"> <div id="header"> <h1 align="right">Fixed Header</h1> <h3>IE6 gets an expression</h3> </div> <div id="content"> <div id="left-index"> <h3>Left</h3> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> <p>Hendrerit eros ridiculus urna ipsum leo a ac sed tortor nisl. Tincidunt Morbi justo dis odio sit non sapien enim a augue. Sapien odio dui est Sed nisl id id malesuada sagittis et.</p> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> <p>Hendrerit eros ridiculus urna ipsum leo a ac sed tortor nisl. Tincidunt Morbi justo dis odio sit non sapien enim a augue. Sapien odio dui est Sed nisl id id malesuada sagittis et.</p> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> <p>Hendrerit eros ridiculus urna ipsum leo a ac sed tortor nisl. Tincidunt Morbi justo dis odio sit non sapien enim a augue. Sapien odio dui est Sed nisl id id malesuada sagittis et.</p> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> <p>Hendrerit eros ridiculus urna ipsum leo a ac sed tortor nisl. Tincidunt Morbi justo dis odio sit non sapien enim a augue. Sapien odio dui est Sed nisl id id malesuada sagittis et.</p> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> <p>Hendrerit eros ridiculus urna ipsum leo a ac sed tortor nisl. Tincidunt Morbi justo dis odio sit non sapien enim a augue. Sapien odio dui est Sed nisl id id malesuada sagittis et.</p> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> </div> <div id="middle-index"> <h3>Middle</h3> <p>Lorem ipsum sed pede non adipiscing nulla lacinia ipsum quis ac Integer. Ut consectetuer Cras fringilla Ut non gravida morbi Maecenas semper vel. Vestibulum quis In Nulla Vivamus Sed feugiat Quisque et ipsum tincidunt. Semper vitae cursus metus risus enim gravida tellus id dignissim nec. Justo laoreet dui commodo Integer malesuada vel quis vel consequat metus. Nec id dolor Aliquam Nullam gravida libero montes nunc ante Nulla. Tortor id.</p> <p>Lorem ipsum sed pede non adipiscing nulla lacinia ipsum quis ac Integer. Ut consectetuer Cras fringilla Ut non gravida morbi Maecenas semper vel. Vestibulum quis In Nulla Vivamus Sed feugiat Quisque et ipsum tincidunt. Semper vitae cursus metus risus enim gravida tellus id dignissim nec. Justo laoreet dui commodo Integer malesuada vel quis vel consequat metus. Nec id dolor Aliquam Nullam gravida libero montes nunc ante Nulla. Tortor id.</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> <p class="lgmarg">testing text for scrolling</p> </div> <div id="right-index"> <h3>Right</h3> <p>Lorem ipsum dolor sit amet consectetuer quis tempus tristique facilisi Vestibulum. Gravida rhoncus orci leo neque mattis felis Sed et tincidunt tellus. Massa ac condimentum elit ridiculus eget urna wisi id Suspendisse ullamcorper.</p> <p>Hendrerit eros ridiculus urna ipsum leo a ac sed tortor nisl. Tincidunt Morbi justo dis odio sit non sapien enim a augue. Sapien odio dui est Sed nisl id id malesuada sagittis et.</p> </div> </div><!--end content--> </div>

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• Enable wireless on Dell Inspiron 1300

  - by Simon

  As per subject, I've looked at various resources and attempted ndiswrapper solutions, found a one-click solution that lead to a 404 and this but none works. I've run all updates. Once I managed to lose my wired connection as well and had to reinstall. This is my first hour with Linux. iwconfig gives this before I do anything: lo no wireless extensions. wlan0 IEEE 802.11bg ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=0 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:on eth0 no wireless extens Thanks for responding lspci returns 00:00.0 Host bridge: Intel Corporation Mobile 915GM/PM/GMS/910GML Express Processor to DRAM Controller (rev 03) Subsystem: Dell Device 01c9 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR- INTx- Latency: 0 Capabilities: <access denied> Kernel driver in use: agpgart-intel 00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03) (prog-if 00 [VGA controller]) Subsystem: Dell Device 01c9 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 16 Region 0: Memory at dff00000 (32-bit, non-prefetchable) [size=512K] Region 1: I/O ports at eff8 [size=8] Region 2: Memory at c0000000 (32-bit, prefetchable) [size=256M] Region 3: Memory at dfec0000 (32-bit, non-prefetchable) [size=256K] Expansion ROM at <unassigned> [disabled] Capabilities: <access denied> Kernel driver in use: i915 Kernel modules: intelfb, i915 00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03) Subsystem: Dell Device 01c9 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Region 0: Memory at dff80000 (32-bit, non-prefetchable) [size=512K] Capabilities: <access denied> 00:1b.0 Audio device: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 03) Subsystem: Dell Device 01c9 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 42 Region 0: Memory at dfebc000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 00:1c.0 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 1 (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=0b, subordinate=0b, sec-latency=0 I/O behind bridge: 00002000-00002fff Memory behind bridge: 30000000-301fffff Prefetchable memory behind bridge: 0000000030200000-00000000303fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: <access denied> Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.3 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 4 (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=0c, subordinate=0d, sec-latency=0 I/O behind bridge: 0000d000-0000dfff Memory behind bridge: dfc00000-dfdfffff Prefetchable memory behind bridge: 00000000d0000000-00000000d01fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: <access denied> Kernel driver in use: pcieport Kernel modules: shpchp 00:1d.0 USB controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 03) (prog-if 00 [UHCI]) Subsystem: Dell Device 01c9 Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 16 Region 4: I/O ports at bf80 [size=32] Kernel driver in use: uhci_hcd 00:1d.1 USB controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 03) (prog-if 00 [UHCI]) Subsystem: Dell Device 01c9 Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin B routed to IRQ 17 Region 4: I/O ports at bf60 [size=32] Kernel driver in use: uhci_hcd 00:1d.2 USB controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 03) (prog-if 00 [UHCI]) Subsystem: Dell Device 01c9 Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin C routed to IRQ 18 Region 4: I/O ports at bf40 [size=32] Kernel driver in use: uhci_hcd 00:1d.3 USB controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 03) (prog-if 00 [UHCI]) Subsystem: Dell Device 01c9 Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin D routed to IRQ 19 Region 4: I/O ports at bf20 [size=32] Kernel driver in use: uhci_hcd 00:1d.7 USB controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 03) (prog-if 20 [EHCI]) Subsystem: Dell Device 01c9 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 16 Region 0: Memory at b0000000 (32-bit, non-prefetchable) [size=1K] Capabilities: <access denied> Kernel driver in use: ehci_hcd 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev d3) (prog-if 01 [Subtractive decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Bus: primary=00, secondary=02, subordinate=02, sec-latency=32 I/O behind bridge: 0000f000-00000fff Memory behind bridge: dfb00000-dfbfffff Prefetchable memory behind bridge: 00000000fff00000-00000000000fffff Secondary status: 66MHz- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort+ <SERR- <PERR- BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: <access denied> 00:1f.0 ISA bridge: Intel Corporation 82801FBM (ICH6M) LPC Interface Bridge (rev 03) Subsystem: Dell Device 01c9 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Kernel modules: iTCO_wdt, intel-rng 00:1f.1 IDE interface: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) IDE Controller (rev 03) (prog-if 8a [Master SecP PriP]) Subsystem: Dell Device 01c9 Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 16 Region 0: I/O ports at 01f0 [size=8] Region 1: I/O ports at 03f4 [size=1] Region 2: I/O ports at 0170 [size=8] Region 3: I/O ports at 0374 [size=1] Region 4: I/O ports at bfa0 [size=16] Kernel driver in use: ata_piix 02:00.0 Ethernet controller: Broadcom Corporation BCM4401-B0 100Base-TX (rev 02) Subsystem: Dell Device 01c9 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 64 Interrupt: pin A routed to IRQ 18 Region 0: Memory at dfbfc000 (32-bit, non-prefetchable) [size=8K] Capabilities: <access denied> Kernel driver in use: b44 Kernel modules: b44 02:03.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02) Subsystem: Dell Wireless 1370 WLAN Mini-PCI Card Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 64 Interrupt: pin A routed to IRQ 17 Region 0: Memory at dfbfe000 (32-bit, non-prefetchable) [size=8K] Kernel driver in use: b43-pci-bridge Kernel modules: ssb and the rfkill shows 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no Just checking addtional drivers. Says no additional driver installed in this system

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• elffile: ELF Specific File Identification Utility

  - by user9154181

  Solaris 11 has a new standard user level command, /usr/bin/elffile. elffile is a variant of the file utility that is focused exclusively on linker related files: ELF objects, archives, and runtime linker configuration files. All other files are simply identified as "non-ELF". The primary advantage of elffile over the existing file utility is in the area of archives — elffile examines the archive members and can produce a summary of the contents, or per-member details. The impetus to add elffile to Solaris came from the effort to extend the format of Solaris archives so that they could grow beyond their previous 32-bit file limits. That work introduced a new archive symbol table format. Now that there was more than one possible format, I thought it would be useful if the file utility could identify which format a given archive is using, leading me to extend the file utility: % cc -c ~/hello.c % ar r foo.a hello.o % file foo.a foo.a: current ar archive, 32-bit symbol table % ar r -S foo.a hello.o % file foo.a foo.a: current ar archive, 64-bit symbol table In turn, this caused me to think about all the things that I would like the file utility to be able to tell me about an archive. In particular, I'd like to be able to know what's inside without having to unpack it. The end result of that train of thought was elffile. Much of the discussion in this article is adapted from the PSARC case I filed for elffile in December 2010: PSARC 2010/432 elffile Why file Is No Good For Archives And Yet Should Not Be Fixed The standard /usr/bin/file utility is not very useful when applied to archives. When identifying an archive, a user typically wants to know 2 things: Is this an archive? Presupposing that the archive contains objects, which is by far the most common use for archives, what platform are the objects for? Are they for sparc or x86? 32 or 64-bit? Some confusing combination from varying platforms? The file utility provides a quick answer to question (1), as it identifies all archives as "current ar archive". It does nothing to answer the more interesting question (2). To answer that question, requires a multi-step process: Extract all archive members Use the file utility on the extracted files, examine the output for each file in turn, and compare the results to generate a suitable summary description. Remove the extracted files It should be easier and more efficient to answer such an obvious question. It would be reasonable to extend the file utility to examine archive contents in place and produce a description. However, there are several reasons why I decided not to do so: The correct design for this feature within the file utility would have file examine each archive member in turn, applying its full abilities to each member. This would be elegant, but also represents a rather dramatic redesign and re-implementation of file. Archives nearly always contain nothing but ELF objects for a single platform, so such generality in the file utility would be of little practical benefit. It is best to avoid adding new options to standard utilities for which other implementations of interest exist. In the case of the file utility, one concern is that we might add an option which later appears in the GNU version of file with a different and incompatible meaning. Indeed, there have been discussions about replacing the Solaris file with the GNU version in the past. This may or may not be desirable, and may or may not ever happen. Either way, I don't want to preclude it. Examining archive members is an O(n) operation, and can be relatively slow with large archives. The file utility is supposed to be a very fast operation. I decided that extending file in this way is overkill, and that an investment in the file utility for better archive support would not be worth the cost. A solution that is more narrowly focused on ELF and other linker related files is really all that we need. The necessary code for doing this already exists within libelf. All that is missing is a small user-level wrapper to make that functionality available at the command line. In that vein, I considered adding an option for this to the elfdump utility. I examined elfdump carefully, and even wrote a prototype implementation. The added code is small and simple, but the conceptual fit with the rest of elfdump is poor. The result complicates elfdump syntax and documentation, definite signs that this functionality does not belong there. And so, I added this functionality as a new user level command. The elffile Command The syntax for this new command is elffile [-s basic | detail | summary] filename... Please see the elffile(1) manpage for additional details. To demonstrate how output from elffile looks, I will use the following files: FileDescription configA runtime linker configuration file produced with crle dwarf.oAn ELF object /etc/passwdA text file mixed.aArchive containing a mixture of ELF and non-ELF members mixed_elf.aArchive containing ELF objects for different machines not_elf.aArchive containing no ELF objects same_elf.aArchive containing a collection of ELF objects for the same machine. This is the most common type of archive. The file utility identifies these files as follows: % file config dwarf.o /etc/passwd mixed.a mixed_elf.a not_elf.a same_elf.a config: Runtime Linking Configuration 64-bit MSB SPARCV9 dwarf.o: ELF 64-bit LSB relocatable AMD64 Version 1 /etc/passwd: ascii text mixed.a: current ar archive, 32-bit symbol table mixed_elf.a: current ar archive, 32-bit symbol table not_elf.a: current ar archive same_elf.a: current ar archive, 32-bit symbol table By default, elffile uses its "summary" output style. This output differs from the output from the file utility in 2 significant ways: Files that are not an ELF object, archive, or runtime linker configuration file are identified as "non-ELF", whereas the file utility attempts further identification for such files. When applied to an archive, the elffile output includes a description of the archive's contents, without requiring member extraction or other additional steps. Applying elffile to the above files: % elffile config dwarf.o /etc/passwd mixed.a mixed_elf.a not_elf.a same_elf.a config: Runtime Linking Configuration 64-bit MSB SPARCV9 dwarf.o: ELF 64-bit LSB relocatable AMD64 Version 1 /etc/passwd: non-ELF mixed.a: current ar archive, 32-bit symbol table, mixed ELF and non-ELF content mixed_elf.a: current ar archive, 32-bit symbol table, mixed ELF content not_elf.a: current ar archive, non-ELF content same_elf.a: current ar archive, 32-bit symbol table, ELF 64-bit LSB relocatable AMD64 Version 1 The output for same_elf.a is of particular interest: The vast majority of archives contain only ELF objects for a single platform, and in this case, the default output from elffile answers both of the questions about archives posed at the beginning of this discussion, in a single efficient step. This makes elffile considerably more useful than file, within the realm of linker-related files. elffile can produce output in two other styles, "basic", and "detail". The basic style produces output that is the same as that from 'file', for linker-related files. The detail style produces per-member identification of archive contents. This can be useful when the archive contents are not homogeneous ELF object, and more information is desired than the summary output provides: % elffile -s detail mixed.a mixed.a: current ar archive, 32-bit symbol table mixed.a(dwarf.o): ELF 32-bit LSB relocatable 80386 Version 1 mixed.a(main.c): non-ELF content mixed.a(main.o): ELF 64-bit LSB relocatable AMD64 Version 1 [SSE]

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• Collation errors in business

  - by Rob Farley

  At the PASS Summit last month, I did a set (Lightning Talk) about collation, and in particular, the difference between the “English” spoken by people from the US, Australia and the UK. One of the examples I gave was that in the US drivers might stop for gas, whereas in Australia, they just open the window a little. This is what’s known as a paraprosdokian, where you suddenly realise you misunderstood the first part of the sentence, based on what was said in the second. My current favourite is Emo Phillip’s line “I like to play chess with old men in the park, but it can be hard to find thirty-two of them.” Essentially, this a collation error, one that good comedians can get mileage from. Unfortunately, collation is at its worst when we have a computer comparing two things in different collations. They might look the same, and sound the same, but if one of the things is in SQL English, and the other one is in Windows English, the poor database server (with no sense of humour) will get suspicious of developers (who all have senses of humour, obviously), and declare a collation error, worried that it might not realise some nuance of the language. One example is the common scenario of a case-sensitive collation and a case-insensitive one. One may think that “Rob” and “rob” are the same, but the other might not. Clearly one of them is my name, and the other is a verb which means to steal (people called “Nick” have the same problem, of course), but I have no idea whether “Rob” and “rob” should be considered the same or not – it depends on the collation. I told a lie before – collation isn’t at its worst in the computer world, because the computer has the sense to complain about the collation issue. People don’t. People will say something, with their own understanding of what they mean. Other people will listen, and apply their own collation to it. I remember when someone was asking me about a situation which had annoyed me. They asked if I was ‘pissed’, and I said yes. I meant that I was annoyed, but they were asking if I’d been drinking. It took a moment for us to realise the misunderstanding. In business, the problem is escalated. A business user may explain something in a particular way, using terminology that they understand, but using words that mean something else to a technical person. I remember a situation with a checkbox on a form (back in VB6 days from memory). It was used to indicate that something was approved, and indicated whether a particular database field should store True or False – nothing more. However, the client understood it to mean that an entire workflow system would be implemented, with different users have permission to approve items and more. The project manager I’d just taken over from clearly hadn’t appreciated that, and I faced a situation of explaining the misunderstanding to the client. Lots of fun... Collation errors aren’t just a database setting that you can ignore. You need to remember that Americans speak a different type of English to Aussies and Poms, and techies speak a different language to their clients.

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• Download and Try Out the New ‘Australis UI’ Test-Build of Firefox for Windows

  - by Asian Angel

  We have all been hearing about the upcoming changes to the UI in Firefox and now the first test build is finally available to try out. Mozilla software engineer Jared Wein has worked hard and put together an unofficial (at the moment) Australis UI build that you can download as a regular installer or as a portable in zip file format. Here is a closer look at the new tab setup in the Australis build. Notice that only the focused tab is non-transparent while the non-active tabs blend nicely into the background. Special Note: Our screenshots were taken in Windows 8, thus the slightly different looking (non-rounded) corners on the app window. The test build only works on Windows at the moment, but you can bet that Linux and MacOS builds are coming in the near future! How to Make Your Laptop Choose a Wired Connection Instead of Wireless HTG Explains: What Is Two-Factor Authentication and Should I Be Using It? HTG Explains: What Is Windows RT and What Does It Mean To Me?

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• Pure virtual or abstract, what's in a name?

  - by Steven Jeuris

  While discussing a question about virtual functions on Stack Overflow, I wondered whether there was any official naming for pure (abstract) and non-pure virtual functions. I always relied on wikipedia for my information, which states that pure and non-pure virtual functions are the general term. Unfortunately, the article doesn't back it up with a origin or references. To quote Jon Skeet's answer to my reply that pure and non-pure are the general term used: @Steven: Hmm... possibly, but I've only ever seen it in the context of C++ before. I suspect anyone talking about them is likely to have a C++ background :) Did the terms originate from C++, or were they first defined or implemented in a earlier language, and are they the 'official' scientific terms?

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• PTLQueue : a scalable bounded-capacity MPMC queue

  - by Dave

  Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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