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• CodePlex Daily Summary for Sunday, June 10, 2012

  CodePlex Daily Summary for Sunday, June 10, 2012Popular ReleasesRCon Development Server: BF3DevServer-Console v0.3: Solved issues9 10 11 13 14 15 16 17SVNUG.CodePlex: Cloud Development with Windows Azure: This release contains the slides for the Cloud Development with Windows Azure presentation.Image Cropper for Umbraco 5: Image Cropper for Umbraco 5.1: for Umbraco version 5.1SHA-1 Hash Checker: SHA-1 Hash Checker (for Windows): Fixed major bugs. Removed false negatives.Grid.Mvc: Grid.Mvc 1.3: Added Html helper extension methods (see: Documentation) Fixed minor bugs Changed Namespace to 'GridMvc'AutoUpdaterdotNET: AutoUpdater.NET 1.0: Everything seems perfect if you find any problem you can report to http://www.rbsoft.org/contact.htmlMedia Companion: Media Companion 3.503b: It has been a while, so it's about time we release another build! Major effort has been for fixing trailer downloads, plus a little bit of work for episode guide tag in TV show NFOs.Microsoft SQL Server Product Samples: Database: AdventureWorks Sample Reports 2008 R2: AdventureWorks Sample Reports 2008 R2.zip contains several reports include Sales Reason Comparisons SQL2008R2.rdl which uses Adventure Works DW 2008R2 as a data source reference. For more information, go to Sales Reason Comparisons report.Json.NET: Json.NET 4.5 Release 7: Fix - Fixed Metro build to pass Windows Application Certification Kit on Windows 8 Release Preview Fix - Fixed Metro build error caused by an anonymous type Fix - Fixed ItemConverter not being used when serializing dictionaries Fix - Fixed an incorrect object being passed to the Error event when serializing dictionaries Fix - Fixed decimal properties not being correctly ignored with DefaultValueHandlingLINQ Extensions Library: 1.0.3.0: New to release 1.0.3.0:Combinatronics: Combinations (unique) Combinations (with repetition) Permutations (unique) Permutations (with repetition) Convert jagged arrays to fixed multidimensional arrays Convert fixed multidimensional arrays to jagged arrays ElementAtMax ElementAtMin ElementAtAverage New set of array extension (1.0.2.8):Rotate Flip Resize (maintaing data) Split Fuse Replace Append and Prepend extensions (1.0.2.7) IndexOf extensions (1.0.2.7) Ne...????????API for .Net SDK: SDK for .Net ??? Release 1: ??? - ??.Net 2.0/3.5/4.0????。??????VS2010??????????。VS2008????????，??????????。 ??? - ??.Net 4.0???SDK??????Dynamic????????。 ??? - OAuth??????AccessToken?VerifierAccessToken??。??Token?????????Client?。 ?? - OAuth???2?????。 ?????AccessToken?????????。???AppKey，AppSecret?CallbackUrl ???AccessToken????????API???Client?????。???AppKey，AppSecret?AccessToken ?? - ??OAuth??????????????????????????CallbackUrl??，??GetAuthorizeURL, GetAccessTokenByAuthorizationCode, ClientLogin?????????CallbackUr...Audio Pitch & Shift: Audio Pitch And Shift 4.5.0: Added Instruments tab for modules Open folder content feature Some bug fixesPython Tools for Visual Studio: 1.5 Beta 1: We’re pleased to announce the release of Python Tools for Visual Studio 1.5 Beta. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including: • Supports CPython, IronPython, Jython and PyPy • Python editor with advanced member, signature intellisense and refactoring • Code navigation: “Find all refs”, goto definition, and object browser • Local and remote debugging •...Circuit Diagram: Circuit Diagram 2.0 Beta 1: New in this release: Automatically flip components when placing Delete components using keyboard delete key Resize document Document properties window Print document Recent files list Confirm when exiting with unsaved changes Thumbnail previews in Windows Explorer for CDDX files Show shortcut keys in toolbox Highlight selected item in toolbox Zoom using mouse scroll wheel while holding down ctrl key Plugin support for: Custom export formats Custom import formats Open...Umbraco CMS: Umbraco CMS 5.2 Beta: The future of Umbracov5 represents the future architecture of Umbraco, so please be aware that while it's technically superior to v4 it's not yet on a par feature or performance-wise. What's new? For full details see our http://progress.umbraco.org task tracking page showing all items complete for 5.2. In a nutshellPackage Builder Starter Kits Dynamic Extension Methods Querying / IsHelpers Friendly alt template URLs Localization Various bug fixes / performance enhancements Gett...JayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.0.5: JayData is a unified data access library for JavaScript developers to query and update data from different sources like WebSQL, IndexedDB, OData, Facebook or YQL. See it in action in this 6 minutes video New features in JayData 1.0.5http://jaydata.org/blog/jaydata-1.0.5-is-here-with-authentication-support-and-more http://jaydata.org/blog/release-notes Sencha Touch 2 module (read-only)This module can be used to bind data retrieved by JayData to Sencha Touch 2 generated user interface. (exam...Application Architecture Guidelines: Application Architecture Guidelines 3.0.7: 3.0.7Jolt Environment: Jolt v2 Stable: Many new features. Follow development here for more information: http://www.rune-server.org/runescape-development/rs-503-client-server/projects/298763-jolt-environment-v2.html Setup instructions in downloadSharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.5): New fetures:Multilingual Support Max users property in Standings Web Part Games time zone change (UTC +1) bug fix - Version 1.4 locking problem http://euro2012.codeplex.com/discussions/358262 bug fix - Field Title not found (v.1.3) German SP http://euro2012.codeplex.com/discussions/358189#post844228 Bug fix - Access is denied.for users with contribute rights Bug fix - Installing on non-English version of SharePoint Bug fix - Title Rules Installing SharePoint Euro 2012 PredictorSharePoint E...myManga: myManga v1.0.0.4: ChangeLogUpdating from Previous Version: Extract contents of Release - myManga v1.0.0.4.zip to previous version's folder. Replaces: myManga.exe BakaBox.dll CoreMangaClasses.dll Manga.dll Plugins/MangaReader.manga.dll Plugins/MangaFox.manga.dll Plugins/MangaHere.manga.dll Plugins/MangaPanda.manga.dllNew ProjectsDatabase Based Config Management: This project helps you to consolidate all your app configs into DB and access it from single location. eLogistics: My logistics systemFacebook Web Parts for SharePoint 2010: Going beyond authentication with Facebook and SharePoint 2010.FsJson: A JSON Parser in F#Google Web Service API for Windows Phone: Google Web Service API ported to .NET for Windows Phone.Hedge when you can, not when you have to.: Classic Black-Scholes/Merton option hedging assumes options are continuously hedged. This project is for exploring what happens in the real world of option hedging.Infragistics via PRISM: Using Infragistics RibbonBar and DockManager with PRISMLightBus???????: LightBus???????????????；????,????,????,????,????,????；????,????；??????,??????,????,????；????????。 ????????： 1. Silverlight Out-of-Browser?? 2. Windows 8 Metro??metaPost: metaPost provides a MetaWeblog interface for managing content in DotNetNuke modules using MetaWeblog enabled editors such as Windows Live Writer. The metaPost module defines a framework that can be used to easily add MetaWeblog publishing support to existing DotNetNuke modules.MPerfs Tool: MPerfs is a tool of MSSQL Performance Tool Web site, developped in php/javascript with graphicals and tables, using a MSSQL database contained DMVs data aggregations and historicals. Supported Versions : Microsoft SQLServer 2005 and 2008 R1 (2008 R2 soon). Important : The tool doesn't monitor SSAS, SSIS or SSRSNanoMVVM: a lightweight wpf MVVM framework: This is a lightweight C# 4.0 ViewModel-first MVVM framework designed to aid in the creation of desktop wpf applications.Open Personal Response System: OpenPRS is designed to be an audience-feedback tool for presenters to keep audiences engaged in a presentation as well as facilitating information gathering from the audience and presentation to the presenter and other interested parties. Panda TimeManager: Panda TimeManager is a software for management of timesheets.Progetto Sicurezza: A *VERY* basic implementation of a Certification Authority and a Client to use it, made with vb.net, BouncyCastle and iTextSharp.Proyectos de Pruebas de UTB Minor Sql 2012: Proyectos de Pruebas de UTB Minor Sql 2012Really fast Javascript Base64 encoder/decoder with utf-8 suppot: If you wonder why another one, then focus on the title. I’ve seen a lot of implementations (custom ones and in libraries/frameworks) that are fast, but not as this one. What you get is significant performance in encoding and light speed in decoding.Rezerwior - JSF: Projekt aplikacji webowej w technologi Java Server Faces 2.0Rules of Acquisition: Ferengi rules of acquistion for Windows Phone.SCOMA - FIM Connector for System Center Orchestrator: SCOMA is the acronym for the Web Service-based FIM connector (aka Management Agent) for System Center Orchestrator, short SCO. SCOMA is written in C# and based on the new ECMA2 (Extensible Connectivity 2.0 Management Agents) interface that is part of FIM 2010 R2 and FIM 2010 Update 2.SHA-1 Hash Checker: Offline command line tool that generates a SHA-1 hash for a text string or pass-phrase. Additionally, you may check your hash against published lists of compromised hashes, to check whether your password has been compromised or not.Testprojekt: Dies ist nur ein TestTmib Video Downloader: A small youtube video downloader. Created in C#TVGrid: watch several web streams simultaneously??: ????、???????ARPG

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• Cannot connect to MySQL with JDBC - Connection Timeout - Ubuntu 9.04

  - by gav

  I am running Ubuntu and am ultimately trying to connect Tomcat to my MySQL database using JDBC. It has worked previously but after a reboot the instance now fails to connect. Both Tomcat 6 and MySQL 5.0.75 are on the same machine Connection string: jdbc:mysql:///localhost:3306 I can connect to MySQL on the command line using the mysql command The my.cnf file is pretty standard (Available on request) has bind address: 127.0.0.1 I cannot Telnet to the MySQL port despite netstat saying MySQL is listening I have one IpTables rule to forward 80 - 8080 and no firewall I'm aware of. I'm pretty new to this and I'm not sure what else to test. I don't know whether I should be looking in etc/interfaces and if I did what to look for. It's weird because it used to work but after a reboot it's down so I must have changed something.... :). I realise a timeout indicates the server is not responding and I assume it's because the request isn't actually getting through. I installed MySQL via apt-get and Tomcat manually. MySqld processes root@88:/var/log/mysql# ps -ef | grep mysqld root 21753 1 0 May27 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe mysql 21792 21753 0 May27 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --skip-external-locking --port=3306 --socket=/var/run/mysqld/mysqld.sock root 21793 21753 0 May27 ? 00:00:00 logger -p daemon.err -t mysqld_safe -i -t mysqld root 21888 13676 0 11:23 pts/1 00:00:00 grep mysqld Netstat root@88:/var/log/mysql# netstat -lnp | grep mysql tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 21792/mysqld unix 2 [ ACC ] STREAM LISTENING 1926205077 21792/mysqld /var/run/mysqld/mysqld.sock Toy Connection Class root@88:~# cat TestConnect/TestConnection.java import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class TestConnection { public static void main(String args[]) throws Exception { Connection con = null; try { Class.forName("com.mysql.jdbc.Driver").newInstance(); System.out.println("Got driver"); con = DriverManager.getConnection( "jdbc:mysql:///localhost:3306", "uname", "pass"); System.out.println("Got connection"); if(!con.isClosed()) System.out.println("Successfully connected to " + "MySQL server using TCP/IP..."); } finally { if(con != null) con.close(); } } } Toy Connection Class Output Note: This is the same error I get from Tomcat. root@88:~/TestConnect# java -cp mysql-connector-java-5.1.12-bin.jar:. TestConnection Got driver Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 1 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122) at TestConnection.main(TestConnection.java:14) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2181) ... 12 more Caused by: java.net.ConnectException: Connection timed out at java.net.PlainSocketImpl.socketConnect(Native Method) ... 13 more Telnet Output root@88:~/TestConnect# telnet localhost 3306 Trying 127.0.0.1... telnet: Unable to connect to remote host: Connection timed out

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• CodePlex Daily Summary for Tuesday, June 05, 2012

  CodePlex Daily Summary for Tuesday, June 05, 2012Popular ReleasesApplication Architecture Guidelines: Application Architecture Guidelines 3.0.7: 3.0.7Jolt Environment: Jolt v2 Stable: Many new features. Follow development here for more information: http://www.rune-server.org/runescape-development/rs-503-client-server/projects/298763-jolt-environment-v2.html Setup instructions in downloadtedplay: tedplay 1.0: First public release of the Commodore 264 family (C16, plus/4) music player based on the SDL version of YAPE http://yape.homeserver.hu.SharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.5): New fetures:Multilingual Support Max users property in Standings Web Part Games time zone change (UTC +1) bug fix - Version 1.4 locking problem http://euro2012.codeplex.com/discussions/358262 bug fix - Field Title not found (v.1.3) German SP http://euro2012.codeplex.com/discussions/358189#post844228 Bug fix - Access is denied.for users with contribute rights Bug fix - Installing on non-English version of SharePoint Bug fix - Title Rules Installing SharePoint Euro 2012 PredictorSharePoint E...xNet: xNet 2.1.1: Release xNet 2.1.1Command Line Parser Library: 1.9.2.4 stable: This is the first stable of 1.9.* branch. Added tests for HelpText::AutoBuild. Fixed minor formatting error in HelpText::DefaultParsingErrorsHandler.myManga: myManga v1.0.0.4: ChangeLogUpdating from Previous Version: Extract contents of Release - myManga v1.0.0.4.zip to previous version's folder. Replaces: myManga.exe BakaBox.dll CoreMangaClasses.dll Manga.dll Plugins/MangaReader.manga.dll Plugins/MangaFox.manga.dll Plugins/MangaHere.manga.dll Plugins/MangaPanda.manga.dllMVVM Light Toolkit: V4RC (binaries only) including Windows 8 RP: This package contains all the latest DLLs for MVVM Light V4 RC. It includes the DLLs for Windows 8 Release Preview. An updated Nuget package is also available at http://nuget.org/packages/MvvmLightLibsPreviewExtAspNet: ExtAspNet v3.1.7: +2012-06-03 v3.1.7 -?????????BUG，??????RadioButtonList?，AJAX????????BUG（swtseaman、????）。 +?Grid?BoundField、HyperLinkField、LinkButtonField、WindowField??HtmlEncode?HtmlEncodeFormatString（TiDi）。 -HtmlEncode?HtmlEncodeFormatString??????true，??????HTML????????。 -??????Asp.Net??GridView?BoundField?????????。 -http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.boundfield.htmlencode -?Grid?HyperLinkField、WindowField??UrlEncode??，????URL??（???true）。 -?????????????，?????????????...Ela, functional language: Ela Platform 2012.3: 2012.3 is a stabilization release. It contains several improvements to Ela, std lib and Elide. Ela changes Fix:Op code 'Show' didn't work correctly when a format string was a thunk. Fix:Flipping a function wrapped in a thunk caused VM to crush. Fix:A bug fixed in concatenation of a thunk and a lazy list. Fix:Concatenation of a lazy list and a strict list could cause stack overflow in a case of recursive thunks. Fix:A bug fixed in applying 'show' to a result of a lazy and strict list...Cross Site Treeview - For MOSS 2007: Cross Site Treeview-Beta - WSP Solution: Cross Site Treeview-Beta - WSP SolutionLiveChat Starter Kit: LCSK v1.5.2: New features: Visitor location (City - Country) from geo-location Pass configuration via javascript for the chat box New visitor identification (no more using the IP address as visitor identification) To update from 1.5.1 Run the /src/1.5.2-sql-updates.txt SQL script to update your database tables. If you have it installed via NuGet, simply update your package and the file will be included so you can run the update script. New installation The easiest way to add LCSK to your app is by...Kendo UI ASP.NET Sample Applications: Sample Applications (2012-06-01): Sample application(s) demonstrating the use of Kendo UI in ASP.NET applications.Better Explorer: Better Explorer Beta 1: Finally, the first Beta is here! There were a lot of changes, including: Translations into 10 different languages (the translations are not complete and will be updated soon) Conditional Select new tools for managing archives Folder Tools tab new search bar and Search Tab new image editing tools update function many bug fixes, stability fixes, and memory leak fixes other new features as well! Please check it out and if there are any problems, let us know. :) Also, do not forge...Player Framework by Microsoft: Player Framework for Windows 8 Metro (Preview 3): Player Framework for HTML/JavaScript and XAML/C# Metro Style Applications. Additional DownloadsIIS Smooth Streaming Client SDK for Windows 8 Microsoft PlayReady Client SDK for Metro Style Apps Release notes:Support for Windows 8 Release Preview (released 5/31/12) Advertising support (VAST, MAST, VPAID, & clips) Miscellaneous improvements and bug fixesMicrosoft Ajax Minifier: Microsoft Ajax Minifier 4.54: Fix for issue #18161: pretty-printing CSS @media rule throws an exception due to mismatched Indent/Unindent pair.Silverlight Toolkit: Silverlight 5 Toolkit Source - May 2012: Source code for December 2011 Silverlight 5 Toolkit release.Windows 8 Metro RSS Reader: RSS Reader release 6: Changed background and foreground colors Used VariableSizeGrid layout to wrap blog posts with images Sort items with Images first, text-only last Enabled Caching to improve navigation between framesJson.NET: Json.NET 4.5 Release 6: New feature - Added IgnoreDataMemberAttribute support New feature - Added GetResolvedPropertyName to DefaultContractResolver New feature - Added CheckAdditionalContent to JsonSerializer Change - Metro build now always uses late bound reflection Change - JsonTextReader no longer returns no content after consecutive underlying content read failures Fix - Fixed bad JSON in an array with error handling creating an infinite loop Fix - Fixed deserializing objects with a non-default cons...DotNetNuke® Community Edition CMS: 06.02.00: Major Highlights Fixed issue in the Site Settings when single quotes were being treated as escape characters Fixed issue loading the Mobile Premium Data after upgrading from CE to PE Fixed errors logged when updating folder provider settings Fixed the order of the mobile device capabilities in the Site Redirection Management UI The User Profile page was completely rebuilt. We needed User Profiles to have multiple child pages. This would allow for the most flexibility by still f...New ProjectsDish: ????? ???????? ??? ??.DRESSCOLLECTION: THIS IS A MVC APPLICAITON WHICH HELPS IN CREATING RANGE OF CLOTH AND DRESS COLLECTION TO CHOOSE AND BUY.FlowTasks: FlowTasks is a framework to develop human and business workflowGroup3.ERP.Roleadministration: Software zum generieren von RollendefinitionenHierarchical Pages Orchard Module: Creates a Hierarchical Page content type that does everything the built-in Page type does, but items can also contain other pages (and thus are containable by other pages too).hot24.vn: is first my project, it very cu chuoi.Household Manager: fcsdvsdvsdcdLabView interface for windows HPC: This project is a prototype library that attempts to integrate in the same enviroment the Data Acquisition and the Data Analysis systems. The library is a collection of LabVIEW Virtual Instruments that permts the job submission to a Windows HPC cluster. Jobs results can be easaly collected in order to perform actions via the DAQ control. Full documentation and examples are included.markgroves.us: Hello this is the blog template for http://markgroves.us. MostrarDireccion: Muestra la Direccion donde Reside cada personaMSPTH2012: This project is for MSPTH2012. Pattern Rolling File Appender for log4net: Appender for log4net that is combination of PatternFileAppender and RollingFileAppenderPowershell By Example: The vision of Powershell By Example is to give those interested in Powershell the chance to learn Powershell scripting by example with the goal of empowering them to use Powershell to maintain their own Windows environments. Practica Cuarto A: proyecto bakanProvidence: Providence is an application meant to capture audio, video, and screen-shots for various purposes.Proyecto T2: Tarea 2 - aprendiendo a utilizar la herramientaServer Config Tools: ??? ?????? IIS ?????SharePoint Scheduling Assistant: Scheduling assistant built for schools and universities. Works with out-of-the-box list and involves no custom workflows.Steam Group Players: This tool is meant to allow access to Steam community groups with the ability to sort group members according to hours spent playing specific games (as well as overall play time). The reason for starting this project was to allow a "player of the week"-selection that is slightly more complex than picking one by random or just by total hours played (recently).t2belenlm4c: Ana Belen LandaTaskLogger: Handy little pop-up that allows you to track time spent on project tasks. Can be used to generate timesheets.TechnicBlog: ????TPL DataFlow Debugger Visualizer: Graphic debugger visualizer to TPL DataFlow networks enable to see live state of blocks and relations Compatible with VS 2012 RC VsDoc2JsDoc: The goal of this project is to convert VSDoc JavaScript comments of JayData classes to JSDoc comment format. Using this tool you can generate the API reference of your JayData components and keep your JavaScript documentation up-to-date.WorkOutTimer: WorkOutTimer This little tool provides an easy to use timer for your workouts, trainings, and more... It has two time period, one for working, and one to be cool! By default work time is set to 2 minutes, cool time is set to 1minute (Kick boxing settings), but you can set up each period time as you want. You can hang up, restart, or reset time. It offers a high visibility timer. It also counts rounds. So have great workout! If you use it and you think it’s cool for y...XLIFF Editor: This is an attempt at making an open source XLIFF editor for Windows. I am using the Open Language Tools Editor as the primary source for the ideas of the XLIFF Editor. I am new to C# so this is is for me an ambitious learning and hopefull succesfull project. Any help in positive criticism will be looked at gratefully. xNet: xNet - a class library for .NET Framework, which includes: - Classes for work with proxy servers: HTTP, Socks4 (and), Socks5. - Classes for work with HTTP 1.0/1.1 protocol: keep-alive, gzip, deflate, chunked, SSL, proxies and more. - Classes for work with multithreading: _a multithreaded bypassing the collection, asynchronous events and more_. - Classes helpers that extend standard classes .NET Framework: FileHelper, DirectoryHelper, StringHelper, XmlHelper, BitHelper and others.?????? «??????????? ??????»: ??????????? ??????????: description

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• CodePlex Daily Summary for Saturday, June 09, 2012

  CodePlex Daily Summary for Saturday, June 09, 2012Popular ReleasesARCBots API Program: ARCBots API Program v3 STABLE: Stable Release, you can find the update notes in the source code.Microsoft SQL Server Product Samples: Database: AdventureWorks Sample Reports 2008 R2: AdventureWorks Sample Reports 2008 R2.zip contains several reports include Sales Reason Comparisons SQL2008R2.rdl which uses Adventure Works DW 2008R2 as a data source reference. For more information, go to Sales Reason Comparisons report.RULI Chain Code Image Generator: RULI Chain Code BW Image Generator v. 0.4: added features: - 3x3 bitmask support - 7x7 bitmask support - app icon added some refactoring for later library-creationThe Chronicles of Asku: Alpha Test v1.1: Welcome to the Chronicles of Asku alpha test. The current state of the game is 2 tomb floors, level 10 cap, and almost all core systems in the game, excluding a store that you buy armor in. This is just a test for downloading the game, and severe bug hunts... INSTRUCTIONS: When you download the folder, right click within the folder and select EXTRACT ALL Run Setup.exe Follow any on screen instructions DO NOT TRY TO LOAD A CHARACTER IF YOU HAVE NEVER SAVED ONE BEFORE Patch 1.1 -Added a...Json.NET: Json.NET 4.5 Release 7: Fix - Fixed Metro build to pass Windows Application Certification Kit on Windows 8 Release Preview Fix - Fixed Metro build error caused by an anonymous type Fix - Fixed ItemConverter not being used when serializing dictionaries Fix - Fixed an incorrect object being passed to the Error event when serializing dictionaries Fix - Fixed decimal properties not being correctly ignored with DefaultValueHandlingLINQ Extensions Library: 1.0.3.0: New to release 1.0.3.0:Combinatronics: Combinations (unique) Combinations (with repetition) Permutations (unique) Permutations (with repetition) Convert jagged arrays to fixed multidimensional arrays Convert fixed multidimensional arrays to jagged arrays ElementAtMax ElementAtMin ElementAtAverage New set of array extension (1.0.2.8):Rotate Flip Resize (maintaing data) Split Fuse Replace Append and Prepend extensions (1.0.2.7) IndexOf extensions (1.0.2.7) Ne...Audio Pitch & Shift: Audio Pitch And Shift 4.5.0: Added Instruments tab for modules Open folder content feature Some bug fixesPython Tools for Visual Studio: 1.5 Beta 1: We’re pleased to announce the release of Python Tools for Visual Studio 1.5 Beta. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including: • Supports CPython, IronPython, Jython and PyPy • Python editor with advanced member, signature intellisense and refactoring • Code navigation: “Find all refs”, goto definition, and object browser • Local and remote debugging •...Circuit Diagram: Circuit Diagram 2.0 Beta 1: New in this release: Automatically flip components when placing Delete components using keyboard delete key Resize document Document properties window Print document Recent files list Confirm when exiting with unsaved changes Thumbnail previews in Windows Explorer for CDDX files Show shortcut keys in toolbox Highlight selected item in toolbox Zoom using mouse scroll wheel while holding down ctrl key Plugin support for: Custom export formats Custom import formats Open...Umbraco CMS: Umbraco CMS 5.2 Beta: The future of Umbracov5 represents the future architecture of Umbraco, so please be aware that while it's technically superior to v4 it's not yet on a par feature or performance-wise. What's new? For full details see our http://progress.umbraco.org task tracking page showing all items complete for 5.2. In a nutshellPackage Builder Starter Kits Dynamic Extension Methods Querying / IsHelpers Friendly alt template URLs Localization Various bug fixes / performance enhancements Gett...JayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.0.5: JayData is a unified data access library for JavaScript developers to query and update data from different sources like WebSQL, IndexedDB, OData, Facebook or YQL. See it in action in this 6 minutes video New features in JayData 1.0.5http://jaydata.org/blog/jaydata-1.0.5-is-here-with-authentication-support-and-more http://jaydata.org/blog/release-notes Sencha Touch 2 module (read-only)This module can be used to bind data retrieved by JayData to Sencha Touch 2 generated user interface. (exam...32feet.NET: 3.5: This version changes the 32feet.NET library (both desktop and NETCF) to use .NET Framework version 3.5. Previously we compiled for .NET v2.0. There are no code changes from our version 3.4. See the 3.4 release for more information. Changes due to compiling for .NET 3.5Applications should be changed to use NET/NETCF v3.5. Removal of class InTheHand.Net.Bluetooth.AsyncCompletedEventArgs, which we provided on NETCF. We now just use the standard .NET System.ComponentModel.AsyncCompletedEvent...DotNetNuke® Links: 06.02.01: Added new DNN 6.2.0 beta social feature "friends" BugfixesApplication Architecture Guidelines: Application Architecture Guidelines 3.0.7: 3.0.7Jolt Environment: Jolt v2 Stable: Many new features. Follow development here for more information: http://www.rune-server.org/runescape-development/rs-503-client-server/projects/298763-jolt-environment-v2.html Setup instructions in downloadSharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.5): New fetures:Multilingual Support Max users property in Standings Web Part Games time zone change (UTC +1) bug fix - Version 1.4 locking problem http://euro2012.codeplex.com/discussions/358262 bug fix - Field Title not found (v.1.3) German SP http://euro2012.codeplex.com/discussions/358189#post844228 Bug fix - Access is denied.for users with contribute rights Bug fix - Installing on non-English version of SharePoint Bug fix - Title Rules Installing SharePoint Euro 2012 PredictorSharePoint E...myManga: myManga v1.0.0.4: ChangeLogUpdating from Previous Version: Extract contents of Release - myManga v1.0.0.4.zip to previous version's folder. Replaces: myManga.exe BakaBox.dll CoreMangaClasses.dll Manga.dll Plugins/MangaReader.manga.dll Plugins/MangaFox.manga.dll Plugins/MangaHere.manga.dll Plugins/MangaPanda.manga.dllMVVM Light Toolkit: V4RC (binaries only) including Windows 8 RP: This package contains all the latest DLLs for MVVM Light V4 RC. It includes the DLLs for Windows 8 Release Preview. An updated Nuget package is also available at http://nuget.org/packages/MvvmLightLibsPreviewExtAspNet: ExtAspNet v3.1.7: +2012-06-03 v3.1.7 -?????????BUG，??????RadioButtonList?，AJAX????????BUG（swtseaman、????）。 +?Grid?BoundField、HyperLinkField、LinkButtonField、WindowField??HtmlEncode?HtmlEncodeFormatString（TiDi）。 -HtmlEncode?HtmlEncodeFormatString??????true，??????HTML????????。 -??????Asp.Net??GridView?BoundField?????????。 -http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.boundfield.htmlencode -?Grid?HyperLinkField、WindowField??UrlEncode??，????URL??（???true）。 -?????????????，?????????????...LiveChat Starter Kit: LCSK v1.5.2: New features: Visitor location (City - Country) from geo-location Pass configuration via javascript for the chat box New visitor identification (no more using the IP address as visitor identification) To update from 1.5.1 Run the /src/1.5.2-sql-updates.txt SQL script to update your database tables. If you have it installed via NuGet, simply update your package and the file will be included so you can run the update script. New installation The easiest way to add LCSK to your app is by...New ProjectsAdvanceWars: Advance Wars For NetARCBots API Program: This is a simple API program designed for quick use for the ARCBots API.AutoUpdaterdotNET: AutoUpdater.NET is a class library that allows .net developers to easily add auto update functionality to their project.C++ AMP Conformance Test Suite: C++ AMP Conformance Test Suite contains a set of tests to aid in verifying compiler, library, and runtime behaviors as specified in the C++ AMP open specification. DynamicObjectProxy: DOP (Dynamic Object Proxy) é uma biblioteca que permite que qualquer método de qualquer objeto possa ser interceptado através de um proxy dinâmico. Ao interceptar um método, pode-se decorar o objeto, alterando ou recuperando informações sobre o seu comportamento. Extremamente útil para logs, verificações de transações, etc. DOP (Dynamic Object Proxy) is a library that contains classes that makes it possible that any method of any object can be intercepted by a dynamic proxy. By interceptin...EAIP: ???????? Flatland: Artificial life, or A-Life, is a broad and ever emerging field that has found its applications in almost any field: economics, medicine, traffic planning, shopping habits, patterns in music. And it is evident that work with modelling logical life in artificial environments is a necessity for the future software developer. Abbots novella "Flatland: A Romance of Many Dimensions" describes the two dimensional world "Flatland", where life is geometrical shapes that have human-like emotions, but...GameAudioSystem: Simple Audio Game System written with OpenAL to be used with Ogre3D.HyperionSS2P - Simple scan to pdf solution: Simple scan to pdf solution.Issue Impala: Issue Impala is a powerful and elegant issue tracker.KoekyGL Wrapper: A .net wrapper for OpenGL aimed at making it easy to use OpenGL.Marik Sample Project: This is a sample by KitMongoDB Managment Client: Development MongoDB Web client. HTML 5 jQuery. One page web application. When Windows 8 metro is released then Metro style application To.MongoDB.Dynamic: MongoDB.Dynamic is a personal project that I’ve started when I was developing my first application targeting MongoDB as DBMS, using the “official driver” MongoDB.Driver, supported by 10gen. The objective is to provide a lightweight library with some interesting features that speed up development for desktop/web applications that accesses MongoDB databases. MongoDB.Dynamic is oriented to interfaces. You don’t need to create concrete classes of your entities, all you need to do is setup your...My Google Workspace: An easy way to create documents search at Google and read your emails and Much moreqzgfjava: git????，?android??“??”???SP Sticky Notes: SP Sticky Notes allows your users to add sticky notes to a page on your SharePoint site.Weather3: It's Metro Style AppXNA Scumm: This is a rewrite of the ScummVM engine using XNA. ScummVM is an engine that runs old school LucasArts graphical adventure games. It is written completely in C# and the first version will run on PC and Xbox 360. A Windows phone version will probably follow. Of course, you will need to own the original games in order to use it. I will start my work by The Secret of Monkey Island, more specifically the VGA CD version. Monkey Island 2: LeChuck's Revenge and Indiana Jones 4 and Fate of Atl...YoG Community Game: This project is a game, being developed by several members of the Yogscast Community Forums. It is a top-down shooter, based around the protagonist 'Joe', and his adventures through TV shows every day.

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• Thread Synchronisation 101

  - by taspeotis

  Previously I've written some very simple multithreaded code, and I've always been aware that at any time there could be a context switch right in the middle of what I'm doing, so I've always guarded access the shared variables through a CCriticalSection class that enters the critical section on construction and leaves it on destruction. I know this is fairly aggressive and I enter and leave critical sections quite frequently and sometimes egregiously (e.g. at the start of a function when I could put the CCriticalSection inside a tighter code block) but my code doesn't crash and it runs fast enough. At work my multithreaded code needs to be a tighter, only locking/synchronising at the lowest level needed. At work I was trying to debug some multithreaded code, and I came across this: EnterCriticalSection(&m_Crit4); m_bSomeVariable = true; LeaveCriticalSection(&m_Crit4); Now, m_bSomeVariable is a Win32 BOOL (not volatile), which as far as I know is defined to be an int, and on x86 reading and writing these values is a single instruction, and since context switches occur on an instruction boundary then there's no need for synchronising this operation with a critical section. I did some more research online to see whether this operation did not need synchronisation, and I came up with two scenarios it did: The CPU implements out of order execution or the second thread is running on a different core and the updated value is not written into RAM for the other core to see; and The int is not 4-byte aligned. I believe number 1 can be solved using the "volatile" keyword. In VS2005 and later the C++ compiler surrounds access to this variable using memory barriers, ensuring that the variable is always completely written/read to the main system memory before using it. Number 2 I cannot verify, I don't know why the byte alignment would make a difference. I don't know the x86 instruction set, but does mov need to be given a 4-byte aligned address? If not do you need to use a combination of instructions? That would introduce the problem. So... QUESTION 1: Does using the "volatile" keyword (implicity using memory barriers and hinting to the compiler not to optimise this code) absolve a programmer from the need to synchronise a 4-byte/8-byte on x86/x64 variable between read/write operations? QUESTION 2: Is there the explicit requirement that the variable be 4-byte/8-byte aligned? I did some more digging into our code and the variables defined in the class: class CExample { private: CRITICAL_SECTION m_Crit1; // Protects variable a CRITICAL_SECTION m_Crit2; // Protects variable b CRITICAL_SECTION m_Crit3; // Protects variable c CRITICAL_SECTION m_Crit4; // Protects variable d // ... }; Now, to me this seems excessive. I thought critical sections synchronised threads between a process, so if you've got one you can enter it and no other thread in that process can execute. There is no need for a critical section for each variable you want to protect, if you're in a critical section then nothing else can interrupt you. I think the only thing that can change the variables from outside a critical section is if the process shares a memory page with another process (can you do that?) and the other process starts to change the values. Mutexes would also help here, named mutexes are shared across processes, or only processes of the same name? QUESTION 3: Is my analysis of critical sections correct, and should this code be rewritten to use mutexes? I have had a look at other synchronisation objects (semaphores and spinlocks), are they better suited here? QUESTION 4: Where are critical sections/mutexes/semaphores/spinlocks best suited? That is, which synchronisation problem should they be applied to. Is there a vast performance penalty for choosing one over the other? And while we're on it, I read that spinlocks should not be used in a single-core multithreaded environment, only a multi-core multithreaded environment. So, QUESTION 5: Is this wrong, or if not, why is it right? Thanks in advance for any responses :)

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• CodePlex Daily Summary for Friday, June 08, 2012

  CodePlex Daily Summary for Friday, June 08, 2012Popular ReleasesMy Google Workspace: Google Workspace 1.0.0: Useful Google Search workspace that includes web-browsing and applitions access Download it to see it in action, please take a look and let me know your feedback Thanks!Tweetz - Windows Twitter Client Gadget: tweetz 3.1.5.8: Fixes bug where Ctrl+Shift+S sends a tweet when only Ctrl+S should send the tweet.C++ AMP Conformance Test Suite: C++ AMP Conformance Test Suite 0.99.0: Initial release of the C++ AMP Conformance Test Suite.Audio Pitch & Shift: Audio Pitch And Shift 4.5.0: Added Instruments tab for modules Open folder content feature Some bug fixesLINQ to Twitter: LINQ to Twitter Beta v2.0.26: Supports .NET 3.5, .NET 4.0, Silverlight 4.0, Windows Phone 7.1, Client Profile, and Windows 8. 100% Twitter API coverage. Also available via NuGet! Follow @JoeMayo.Python Tools for Visual Studio: 1.5 Beta 1: We’re pleased to announce the release of Python Tools for Visual Studio 1.5 Beta. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including: • Supports CPython, IronPython, Jython and PyPy • Python editor with advanced member, signature intellisense and refactoring • Code navigation: “Find all refs”, goto definition, and object browser • Local and remote debugging •...Circuit Diagram: Circuit Diagram 2.0 Beta 1: New in this release: Automatically flip components when placing Delete components using keyboard delete key Resize document Document properties window Print document Recent files list Confirm when exiting with unsaved changes Thumbnail previews in Windows Explorer for CDDX files Show shortcut keys in toolbox Highlight selected item in toolbox Zoom using mouse scroll wheel while holding down ctrl key Plugin support for: Custom export formats Custom import formats Open...Umbraco CMS: Umbraco CMS 5.2 Beta: The future of Umbracov5 represents the future architecture of Umbraco, so please be aware that while it's technically superior to v4 it's not yet on a par feature or performance-wise. What's new? For full details see our http://progress.umbraco.org task tracking page showing all items complete for 5.2. In a nutshellPackage Builder Starter Kits Dynamic Extension Methods Querying / IsHelpers Friendly alt template URLs Localization Various bug fixes / performance enhancements Gett...JayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.0.5: JayData is a unified data access library for JavaScript developers to query and update data from different sources like WebSQL, IndexedDB, OData, Facebook or YQL. See it in action in this 6 minutes video New features in JayData 1.0.5http://jaydata.org/blog/jaydata-1.0.5-is-here-with-authentication-support-and-more http://jaydata.org/blog/release-notes Sencha Touch 2 module (read-only)This module can be used to bind data retrieved by JayData to Sencha Touch 2 generated user interface. (exam...32feet.NET: 3.5: This version changes the 32feet.NET library (both desktop and NETCF) to use .NET Framework version 3.5. Previously we compiled for .NET v2.0. There are no code changes from our version 3.4. See the 3.4 release for more information. Changes due to compiling for .NET 3.5Applications should be changed to use NET/NETCF v3.5. Removal of class InTheHand.Net.Bluetooth.AsyncCompletedEventArgs, which we provided on NETCF. We now just use the standard .NET System.ComponentModel.AsyncCompletedEvent...DotNetNuke® Links: 06.02.01: Added new DNN 6.2.0 beta social feature "friends" BugfixesApplication Architecture Guidelines: Application Architecture Guidelines 3.0.7: 3.0.7Jolt Environment: Jolt v2 Stable: Many new features. Follow development here for more information: http://www.rune-server.org/runescape-development/rs-503-client-server/projects/298763-jolt-environment-v2.html Setup instructions in downloadSharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.5): New fetures:Multilingual Support Max users property in Standings Web Part Games time zone change (UTC +1) bug fix - Version 1.4 locking problem http://euro2012.codeplex.com/discussions/358262 bug fix - Field Title not found (v.1.3) German SP http://euro2012.codeplex.com/discussions/358189#post844228 Bug fix - Access is denied.for users with contribute rights Bug fix - Installing on non-English version of SharePoint Bug fix - Title Rules Installing SharePoint Euro 2012 PredictorSharePoint E...xNet: xNet 2.1.1: Release xNet 2.1.1Command Line Parser Library: 1.9.2.4 stable: This is the first stable of 1.9.* branch. Added tests for HelpText::AutoBuild. Fixed minor formatting error in HelpText::DefaultParsingErrorsHandler.myManga: myManga v1.0.0.4: ChangeLogUpdating from Previous Version: Extract contents of Release - myManga v1.0.0.4.zip to previous version's folder. Replaces: myManga.exe BakaBox.dll CoreMangaClasses.dll Manga.dll Plugins/MangaReader.manga.dll Plugins/MangaFox.manga.dll Plugins/MangaHere.manga.dll Plugins/MangaPanda.manga.dllMVVM Light Toolkit: V4RC (binaries only) including Windows 8 RP: This package contains all the latest DLLs for MVVM Light V4 RC. It includes the DLLs for Windows 8 Release Preview. An updated Nuget package is also available at http://nuget.org/packages/MvvmLightLibsPreviewExtAspNet: ExtAspNet v3.1.7: +2012-06-03 v3.1.7 -?????????BUG，??????RadioButtonList?，AJAX????????BUG（swtseaman、????）。 +?Grid?BoundField、HyperLinkField、LinkButtonField、WindowField??HtmlEncode?HtmlEncodeFormatString（TiDi）。 -HtmlEncode?HtmlEncodeFormatString??????true，??????HTML????????。 -??????Asp.Net??GridView?BoundField?????????。 -http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.boundfield.htmlencode -?Grid?HyperLinkField、WindowField??UrlEncode??，????URL??（???true）。 -?????????????，?????????????...LiveChat Starter Kit: LCSK v1.5.2: New features: Visitor location (City - Country) from geo-location Pass configuration via javascript for the chat box New visitor identification (no more using the IP address as visitor identification) To update from 1.5.1 Run the /src/1.5.2-sql-updates.txt SQL script to update your database tables. If you have it installed via NuGet, simply update your package and the file will be included so you can run the update script. New installation The easiest way to add LCSK to your app is by...New ProjectsAFSAspnetHandyAppTry: ddddddBlackrain Engine: A real-time rendering, game/cinematic engine.codeplexbsso: codeplexbsso?????codesmith template for DbEntry.Net: codesmith template for DbEntry.NetDevTeamsUnse: Proyecto de software para crear un sistema de gestion para una bibliotecaErrordite Client: Client libraries for Errordite Errordite is a simple plug-in for any .net application that will log details of exceptions generated by your application. Errordite will group together errors that are the same, either automatically or with rules you define. You then decide how to progress with the errors. You can investigate them, request to ignore them or put them on hold while you have more pressing concerns. For further information and to sign up for the beta, please visit http://ww...Expense Tracker V2: Asp.net site to manage expenses on a daily basis.Experiment N-Layer Project: The goal of this project to build a deal application using microsoft nlayer sample project. Goal is to build a complete application with proper documentation. More to add...GoMusicNow Downloader: This is a simple application created to make things a little easier when downloading a whole album worth of mp3s from the gomusicnow.com web site. To use, simply add your gomusicnow username and password, choose a local folder to download the mp3s to, then paste the url of the gomusicnow 'links' page, for the album you have purchased. Once you hit start, the files will be downloaded sequentially. This application is my first windows application, and first time using WPF. Therefore, I ca...Help A Lot(HAL): Dll to help in the developementHospital: The hospital project is built for my dad's hospital in India. The version one's features to be implemented are: 1. Add or edit patient (Deadline: 6/10/2012) 2. Add or edit medical history of a patient 3. Add or edit patient visit 4. Search existing patients 5. Print discharge reportinControl: Basic Inv ControlLongNile_Projects: Mobile devices projectsNucleo Mobile Detection: This project wraps around Wireless Universal Resource FiLe (WURFL) and provides added server-side mobile detection features for ASP.NET web forms and ASP.NET MVC. It provides controls/helpers and extension methods that make device detection support much easier. It also provides some mobile simulation capabilities for testing purposes.Physical Quantities: This library represents all physical quantities, units of measures, unit systems and unit conversions, as stated in different sources, but mainly on Wikipedia.Proyecto cuarto a: este trabajo es de prueba en codeplex 4to Apython otp: an hmac-based one-time password algorithmRadiation IM: This project aims to create a secure IRC like client (in the main ideas). But it brings a lot of new ideas and makes it a quite good place to discuss and share things. In security.RULI Chain Code Image Generator: RULICCimageGeneratorSharePoint 2010 - Selected items export to excel: Out of the box export to excel feature allows to export the complete view, and not the selected items. In order to achieve the functionality of exporting only selected items to excel.social media solidario: Se trata de desarrollar una aplicación web para escritorio y móvil que ofrezca la posibilidad de que expertos en social media puedan compartir su conocimiento en este área con las ONG , se trata de que respondan las preguntas que las ONG formulen y que todo ese conocimiento quede clasificado y a disposición de todosStarfish: Planning and organisation app for Pilates instructors.testddgit060720121: cxvtestddgit060720122: gftestddhg060720121: ,ktestddtfs060720122: cxvtesttom06072012git01: dsadstesttom06072012hg01: fdstitle: lo mejorWii Game Maker: Wii Game Maker is a program made in VB.NET that was made to allow people with little to no programming experience make their Wii ideas into reality.WoJiudeProject: WoJiudeProjectWpf localization without compile: Localization without recompiling, use it to localize your app. (Including xaml support).zzz: zzz

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• Feedback on iterating over type-safe enums

  - by Sumant

  In response to the earlier SO question "Enumerate over an enum in C++", I came up with the following reusable solution that uses type-safe enum idiom. I'm just curious to see the community feedback on my solution. This solution makes use of a static array, which is populated using type-safe enum objects before first use. Iteration over enums is then simply reduced to iteration over the array. I'm aware of the fact that this solution won't work if the enumerators are not strictly increasing. template<typename def, typename inner = typename def::type> class safe_enum : public def { typedef typename def::type type; inner val; static safe_enum array[def::end - def::begin]; static bool init; static void initialize() { if(!init) // use double checked locking in case of multi-threading. { unsigned int size = def::end - def::begin; for(unsigned int i = 0, j = def::begin; i < size; ++i, ++j) array[i] = static_cast<typename def::type>(j); init = true; } } public: safe_enum(type v = def::begin) : val(v) {} inner underlying() const { return val; } static safe_enum * begin() { initialize(); return array; } static safe_enum * end() { initialize(); return array + (def::end - def::begin); } bool operator == (const safe_enum & s) const { return this->val == s.val; } bool operator != (const safe_enum & s) const { return this->val != s.val; } bool operator < (const safe_enum & s) const { return this->val < s.val; } bool operator <= (const safe_enum & s) const { return this->val <= s.val; } bool operator > (const safe_enum & s) const { return this->val > s.val; } bool operator >= (const safe_enum & s) const { return this->val >= s.val; } }; template <typename def, typename inner> safe_enum<def, inner> safe_enum<def, inner>::array[def::end - def::begin]; template <typename def, typename inner> bool safe_enum<def, inner>::init = false; struct color_def { enum type { begin, red = begin, green, blue, end }; }; typedef safe_enum<color_def> color; template <class Enum> void f(Enum e) { std::cout << static_cast<unsigned>(e.underlying()) << std::endl; } int main() { std::for_each(color::begin(), color::end(), &f<color>); color c = color::red; }

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• CodePlex Daily Summary for Thursday, June 07, 2012

  CodePlex Daily Summary for Thursday, June 07, 2012Popular Releases????SDK for .Net 2.0/3.5/4.0 (OAuth2.0+??V2?API): ??VS2008?.net2.0、3.5、4.0????????: ??Upload???“?????IComparer”??????，????????。 ???????.net????VS2010??，?????????。 ????VS2008?.net2.0/3.5?！??Entities???? ???????.net???N????? ??JSON.net??????????? ?.net4.0??API?????dynamic??class ???alpha??，???? ?????????????JSON.net????，??????。 VS2005???????，?????var???，??????????！ ????.net4.0???????????????，?????????LINQ to Twitter: LINQ to Twitter Beta v2.0.26: Supports .NET 3.5, .NET 4.0, Silverlight 4.0, Windows Phone 7.1, Client Profile, and Windows 8. 100% Twitter API coverage. Also available via NuGet! Follow @JoeMayo.Python Tools for Visual Studio: 1.5 Beta 1: We’re pleased to announce the release of Python Tools for Visual Studio 1.5 Beta. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including: • Supports CPython, IronPython, Jython and PyPy • Python editor with advanced member, signature intellisense and refactoring • Code navigation: “Find all refs”, goto definition, and object browser • Local and remote debugging •...Circuit Diagram: Circuit Diagram 2.0 Beta 1: New in this release: Automatically flip components when placing Delete components using keyboard delete key Resize document Document properties window Print document Recent files list Confirm when exiting with unsaved changes Thumbnail previews in Windows Explorer for CDDX files Show shortcut keys in toolbox Highlight selected item in toolbox Zoom using mouse scroll wheel while holding down ctrl key Plugin support for: Custom export formats Custom import formats Open...Umbraco CMS: Umbraco CMS 5.2 Beta: The future of Umbracov5 represents the future architecture of Umbraco, so please be aware that while it's technically superior to v4 it's not yet on a par feature or performance-wise. What's new? For full details see our http://progress.umbraco.org task tracking page showing all items complete for 5.2. In a nutshellPackage Builder Starter Kits Dynamic Extension Methods Querying / IsHelpers Friendly alt template URLs Localization Various bug fixes / performance enhancements Gett...JayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.0.5: JayData is a unified data access library for JavaScript developers to query and update data from different sources like WebSQL, IndexedDB, OData, Facebook or YQL. See it in action in this 6 minutes video New features in JayData 1.0.5http://jaydata.org/blog/jaydata-1.0.5-is-here-with-authentication-support-and-more http://jaydata.org/blog/release-notes Sencha Touch 2 module (read-only)This module can be used to bind data retrieved by JayData to Sencha Touch 2 generated user interface. (exam...32feet.NET: 3.5: This version changes the 32feet.NET library (both desktop and NETCF) to use .NET Framework version 3.5. Previously we compiled for .NET v2.0. There are no code changes from our version 3.4. See the 3.4 release for more information. Changes due to compiling for .NET 3.5Applications should be changed to use NET/NETCF v3.5. Removal of class InTheHand.Net.Bluetooth.AsyncCompletedEventArgs, which we provided on NETCF. We now just use the standard .NET System.ComponentModel.AsyncCompletedEvent...DotNetNuke® Links: 06.02.01: Added new DNN 6.2.0 beta social feature "friends" BugfixesApplication Architecture Guidelines: Application Architecture Guidelines 3.0.7: 3.0.7Jolt Environment: Jolt v2 Stable: Many new features. Follow development here for more information: http://www.rune-server.org/runescape-development/rs-503-client-server/projects/298763-jolt-environment-v2.html Setup instructions in downloadSharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.5): New fetures:Multilingual Support Max users property in Standings Web Part Games time zone change (UTC +1) bug fix - Version 1.4 locking problem http://euro2012.codeplex.com/discussions/358262 bug fix - Field Title not found (v.1.3) German SP http://euro2012.codeplex.com/discussions/358189#post844228 Bug fix - Access is denied.for users with contribute rights Bug fix - Installing on non-English version of SharePoint Bug fix - Title Rules Installing SharePoint Euro 2012 PredictorSharePoint E...xNet: xNet 2.1.1: Release xNet 2.1.1Command Line Parser Library: 1.9.2.4 stable: This is the first stable of 1.9.* branch. Added tests for HelpText::AutoBuild. Fixed minor formatting error in HelpText::DefaultParsingErrorsHandler.myManga: myManga v1.0.0.4: ChangeLogUpdating from Previous Version: Extract contents of Release - myManga v1.0.0.4.zip to previous version's folder. Replaces: myManga.exe BakaBox.dll CoreMangaClasses.dll Manga.dll Plugins/MangaReader.manga.dll Plugins/MangaFox.manga.dll Plugins/MangaHere.manga.dll Plugins/MangaPanda.manga.dllMVVM Light Toolkit: V4RC (binaries only) including Windows 8 RP: This package contains all the latest DLLs for MVVM Light V4 RC. It includes the DLLs for Windows 8 Release Preview. An updated Nuget package is also available at http://nuget.org/packages/MvvmLightLibsPreviewExtAspNet: ExtAspNet v3.1.7: +2012-06-03 v3.1.7 -?????????BUG，??????RadioButtonList?，AJAX????????BUG（swtseaman、????）。 +?Grid?BoundField、HyperLinkField、LinkButtonField、WindowField??HtmlEncode?HtmlEncodeFormatString（TiDi）。 -HtmlEncode?HtmlEncodeFormatString??????true，??????HTML????????。 -??????Asp.Net??GridView?BoundField?????????。 -http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.boundfield.htmlencode -?Grid?HyperLinkField、WindowField??UrlEncode??，????URL??（???true）。 -?????????????，?????????????...LiveChat Starter Kit: LCSK v1.5.2: New features: Visitor location (City - Country) from geo-location Pass configuration via javascript for the chat box New visitor identification (no more using the IP address as visitor identification) To update from 1.5.1 Run the /src/1.5.2-sql-updates.txt SQL script to update your database tables. If you have it installed via NuGet, simply update your package and the file will be included so you can run the update script. New installation The easiest way to add LCSK to your app is by...Kendo UI ASP.NET Sample Applications: Sample Applications (2012-06-01): Sample application(s) demonstrating the use of Kendo UI in ASP.NET applications.Better Explorer: Better Explorer Beta 1: Finally, the first Beta is here! There were a lot of changes, including: Translations into 10 different languages (the translations are not complete and will be updated soon) Conditional Select new tools for managing archives Folder Tools tab new search bar and Search Tab new image editing tools update function many bug fixes, stability fixes, and memory leak fixes other new features as well! Please check it out and if there are any problems, let us know. :) Also, do not for...New ProjectsActiveAttributes: Create attributes that execute code when their target members are called.Blogger Access Library: This is a .NET library that make it easy to post your blog article to Blogger when you want to handle the blogger with .NET (C#, VB, F#...etc) code.cookie.js - Simple JavaScript Cookie Processor: Simple JavaScript Cookie ProcessorDeberPrueba: deber de tareaDNN User Redirect: Allows you to redirect users that are members of specific roles or groups to landing pages within your DotNetNuke website. This is perfect for scenarios such as the following: - redirect unauthenticated users to a Login page - redirect authenticated users to a Welcome page after successful login - redirect users to a page where they need to view/accept Terms of Service - redirect employees who are part of a specific department in your organization to a Departmental landing page When ...Evento-Pro: O Aplicativo contará com uma área de manutenção e cadastro das informações necessárias para seu funcionamento, bem como uma tela para visualização, criação/manutenção dos eventos.Exchange Mailbox Permission Reverse Lookup: Ever wondered a user in which mailboxes has full-access or send-as rights? One common strategy is to use groups to grant permissions on shared mailboxes, where querying the user which groups is member of would do the job. But in case you grant mailbox permissions directly to users (maybe because you are using the Exchange 2010 shared mailbox automapping feature), this tool can come quite handy.Find and Replace word in the sentences: This program used Java Development Kid 6.0 and i were using HighLighter class. It was completed code with source code and then everybody can use in everything. I use it for my assignment of NCC Education on IAD(International Advanced Diploma). GIMS: Graphical ImageMagick ScripterGoogleMaps .NET API: This is a wrapper to use the Google Maps API in a .NET windows application (WinForms and WPF). It works by using a browser control (either WinForms or WPF), and interacting with a JavaScript implementation of Google Maps.Grid.Mvc: Grid.Mvc - is a component that allows you easy construction of HTML tables for displaying, paging and sorting data from a collection of Model objects.HgReleaseNotesGen: A cmd line utility for automatically creating a Release Notes document from a Mercurial repository - currently used by StyleCop.HS FB: Fizz BuzzJaySvcUtil - generate JavaScript context from OData metadata: This tool generates client-side metadata for OData service endpoints, so OData services can be consumed from JavaScript using JayData. Visit http://jaydata.org for detailed documentation, example apps and tutorials. You can download JayData from the [url:JayData CodePlex project|http://jaydata.codeplex.com] Knockout Serializer: Knockout SerializerMarsExplorer: This is a personal projectMulti camera snapshot taker: **this c# winform project is based on DXSnap-2008 sample project ** A few days ago, someone told me that it was not possible to take 3 snapshots , from 3 different webcams , at the same time (e.g. this guy wanted to take snapshots of an item on 3 different axes (X,Y,Z) at the same time. so I 've tried to make it work..mvcEticaret: Ticaret sitesiPush Notification: Push Notification service sample using F# and Duplex NetTcpBinding Reproductor: ReproductorStudyMate: A Internet and mobile based website, where user can make and share Exam revision notes to read them from mobile, attempt objective type questions and chat between online users.SugarSync Folder Provider for DotNetNuke: The SugarSync Folder Provider for DotNetNuke allows you to have direct integration between your cloud-hosted files and the file system in your DotNetNuke website. In using this extension, you will be able to enjoy the management of files in a CMS with the power of cloud file hosting.The SharePoint 2010 Tag Cloud web part for blog web template: The SharePoint 2010 Tag Cloud web part for blog web templateTimeClearWinFreeTime: ?????????IT???????，????????????，????????????（??：?????，??????）。???????????????????????，???????????????，??????，????????，?????55?????Windows????，????????????。 ???????c#,Windows7 ???Windows???????????， Windows XP??????.Netframework3.5????. Netframework3.5????： http://msdn.microsoft.com/zh-cn/netframework/cc378097VoIP based Call Management System (VBCMS): This project intends to focus on new ways of providing road side assistance service and many more using VoIP based systemXaml FlowDocument to PDF Converter: Simple FlowDocument to PDF Converter with paging, header and footer

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• CodePlex Daily Summary for Sunday, August 12, 2012

  CodePlex Daily Summary for Sunday, August 12, 2012Popular ReleasesThisismyusername's codeplex page.: Run! Thunderstorm! Classic Multiplatform: The classic edition now on any device, you don't have to get the touch edition for touch screens!SharePoint Developers & Admins: SPTaxCleaner Tool - Cleaner Taxonomy Data: For more information on the tool and how to use it: SPTaxCleaner Run the tool at your own risk!BugNET Issue Tracker: BugNET 1.1: This release includes bug fixes from the 1.0 release for email notifications, RSS feeds, and several other issues. Please see the change log for a full list of changes. http://support.bugnetproject.com/Projects/ReleaseNotes.aspx?pid=1&m=76 Upgrade Notes The following changes to the web.config in the profile section have occurred: Removed <add name="NotificationTypes" type="String" defaultValue="Email" customProviderData="NotificationTypes;nvarchar;255" />Added <add name="ReceiveEmailNotifi...Virtual Keyboard: Virtual Keyboard v2.0 Source Code: This release has a few added keys that were missing in the earlier versions.????: ????2.0.5: 1、?????????????。RiP-Ripper & PG-Ripper: PG-Ripper 1.4.01: changes NEW: Added Support for Clipboard Function in Mono Version NEW: Added Support for "ImgBox.com" links FIXED: "PixHub.eu" links FIXED: "ImgChili.com" links FIXED: Kitty-Kats Forum loginPlayer Framework by Microsoft: Player Framework for Windows 8 (Preview 5): Support for Smooth Streaming SDK beta 2 Support for live playback New bitrate meter and SD/HD indicators Auto smooth streaming track restriction for snapped mode to conserve bandwidth New "Go Live" button and SeekToLive API Support for offset start times Support for Live position unique from end time Support for multiple audio streams (smooth and progressive content) Improved intellisense in JS version Support for Windows 8 RTM ADDITIONAL DOWNLOADSSmooth Streaming Client SD...Media Companion: Media Companion 3.506b: This release includes an update to the XBMC scrapers, for those who prefer to use this method. There were a number of behind-the-scene tweaks to make Media Companion compatible with the new TMDb-V3 API, so it was considered important to get it out to the users to try it out. Please report back any important issues you might find. For this reason, unless you use the XBMC scrapers, there probably isn't any real necessity to download this one! The only other minor change was one to allow the mc...Avian Mortality Detection Entry Application: Detection Entry: The most recent and up-to-date version of the Detection Entry application. Please click on the CLICKONCE link above to install.NVorbis: NVorbis v0.3: Fix Ogg page reader to correctly handle "split" packets Fix "zero-energy" packet handling Fix packet reader to always merge packets when needed Add statistics properties to VorbisReader.Stats Add multi-stream API (for Ogg files containing multiple Vorbis streams)The Ftp Library - Most simple, full-featured .NET Ftp Library: TheFtpLibrary v1.0: First version. Please report any bug and discuss how to improve this library in 'Discussion' section.VisioAutomation: Visio Power Tools 2010 (Beta): Visio Power Tools 2010 An Add-in for Visio 2010. In Beta but should be very stable. Some Cool Features Import Colors - From Kuler, ColourLovers, or manually enter RGB values Create a Document containing images of all masters in multiple stencils Toggle text case Copy All text from all shapes Export document to XHTML (with embedded SVG) Export document to XAML Updates2012-08-10 - Fixed path handling when generating the HTML stencil catalogXBMC for LCDSmartie: v 0.7.1: Changes: Version 0.7.1 - Removed unused configuration options: You can remove the user and pass section from your LCDSmartie.exe.config Version 0.7.0 - Changed JSON-Protocol to TCP: This means the plugin will run much faster and chances that LCDSmartie will stutter are minimized Note: You will have to change some settings in your LCDSmartie.exe.config, as TCP uses a different port than HTTP (9090 is default in XBMC)WPF RSS Feed Reader: WPF RSS Feed Reader 4.1: WPF RSS Feed Reader 4.1.x This application has been developed using Visual Studio 2010 with .NET 4.0 and Microsoft Expression Blend. It makes use of the MVVM Light Toolkit, more information can be found here Fixed bug when first installed - handle null reference on _proxySetting Fixed bug if trying to open error log but error log doesn't exist yet Added strings to resources Moved AsssemblyInfo centrally and linked to other projectsScutex: Scutex 4th Preview Release 0.4: This is the fourth preview release for the new Scutex 0.4 Beta. This preview release is unstable and contains some UI issues that are being worked on due to an installation of a brand new GUI. The stable version of the 0.4 Beta will be out shortly as soon as this release passes QA. The following were fixed in this release *Fixed an issue with the Upload Product dialog that would cause it to throw an exception. Known Issues *The download service logs grid does not display properlySystem.Net.FtpClient: System.Net.FtpClient 2012.08.08: 2012.08.08 Release. Several changes, see commit notes in source code section. CHM help as well as source for this release are included in the download. Remember that Windows 7 by default (and possibly older versions) will block you from opening the CHM by default due to trust settings. To get around the problem, right click on the CHM, choose properties and click the Un-block button. Please note that this will be the last release tested to compile with the .net 2.0 framework. I will be remov...Isis2 Cloud Computing Library: Isis2 Alpha V1.1.967: This is an alpha pre-release of the August 2012 version of the system. I've been testing and fixing many problems and have also added a new group "lock" API (g.Lock("lock name")/g.Unlock/g.Holder/g.SetLockPolicy); with this, Isis2 can mimic Chubby, Google's locking service. I wouldn't say that the system is entirely stable yet, and I haven't rechecked every single problem I had seen in May/June, but I think it might be good to get some additional use of this release. By now it does seem to...JSON C# Class Generator: JSON CSharp Class Generator 1.3: Support for native JSON.net serializer/deserializer (POCO) New classes layout option: nested classes Better handling of secondary classesAxiom 3D Rendering Engine: v0.8.3376.12322: Changes Since v0.8.3102.12095 ===================================================================== Updated ndoc3 binaries to fix bug Added uninstall.ps1 to nuspec packages fixed revision component in version numbering Fixed sln referencing VS 11 Updated OpenTK Assemblies Added CultureInvarient to numeric parsing Added First Visual Studio 2010 Project Template (DirectX9) Updated SharpInputSystem Assemblies Backported fix for OpenGL Auto-created window not responding to input Fixed freeInterna...DotSpatial: DotSpatial 1.3: This is a Minor Release. See the changes in the issue tracker. Minimal -- includes DotSpatial core and essential extensions Extended -- includes debugging symbols and additional extensions Tutorials are available. Just want to run the software? End user (non-programmer) version available branded as MapWindow Want to add your own feature? Develop a plugin, using the template and contribute to the extension feed (you can also write extensions that you distribute in other ways). Components ...New ProjectsAppFabric Cache Admin Tool: Appfabric Admin tool is a GUI tool provided for Cache Administration. This tool can be used for both Appfabric 1.0 and 1.1 versions.Bootstrap XML Navigation: Bootstrap XML Navigation is an ASP.NET Server Control which provide the ability to off-load your Bootstrap navigation structure to external XML files.Classic MVC: Classic MVC is an MVC framework written entirely in JScript for Microsoft's Classic ASP. Separation of concerns, controllers, partial views and more.Component Spectrum: Component Spectrum is an E-Commerce Application project.Developments in Java: Free Develop JavaDongGPrj: DongGPrjEsShop: ???????，????。。。F# Indent Visual Studio addon: The addon to show how to use SmartIndent and change the indent behavior in F# content.FizzBuzzAssignment: This is HeadSpring assignment.hotfighter: a act game!!!iSoilHotel: It is a hotel management system that using Microsoft N-Layer Architecture as the primary thoughts.KVBL (K's VB6 library) VB6????,????????.: KVBL??VB6??????、???????，????????，??????，????VB????，??????????。????：??????、???、??、????、??、????、??、??、?????、?????、???????，???????……Meteorite: c# game 3d wp7 space ship meteoriteMetro App Helpers: Helper classes for building Metro style app on Windows 8.MobileShop: Mobile shop for Iphone & AndroidMomentum: this is q project pqrticipqtion between meir and david concerning student university project on physics.OneLine: dfgfdgPreflight: Summary HereResilient FileSystemWatcher for monitoring network folders: Drop in replacement for FileSystemWatcher that works for network folders and compensate for network outages, server restarts ect.SkyPoint: A Windows Phone 7 app aimed at novice astronomers.test20120811: summary of this projectVS Unbind Source Control: Remove Source Control bindings from Visual Studio Solution and Project FilesWcf SWA (SFTI) implementation: First releasewebstart: new web tech testwinform_framework: winform_frameworkwtopenapi: wtopen sina weibo sdk txweibosdk qzone sdk

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• Forms bound to updateable ADO recordsets are not updateable when the source includes a JOIN

  - by Art

  I'm developing an application in Access 2007. It uses an .accdb front end connecting to an SQL Server 2005 backend. I use forms that are bound to ADO recordsets at runtime. For the sake of efficiency, the recordsets usually contain only one record, and are queried out on the server: Public Sub SetUpFormRecordset(cn As ADODB.Connection, rstIn As ADODB.Recordset, rstSource As String) Dim cmd As ADODB.Command Dim I As Long Set cmd = New ADODB.Command cn.Errors.Clear ' Recordsets based on command object Execute method are Read Only! With cmd Set .ActiveConnection = cn .CommandType = adCmdText .CommandText = rstSource End With With rstIn .CursorType = adOpenKeyset .LockType = adLockPessimistic 'Check the locktype after opening; optimistic locking is worthless on a bound End With ' form, and ADO might open optimistically without firing an error! rstIn.Open cmd, , adOpenKeyset, adLockPessimistic 'This should run the query on the server and return an updatable recordset With cn If .Errors.Count <> 0 Then For Each errADO In .Errors Call HandleADOErrors(.Errors(I)) I = I + 1 Next errADO End If End With End Sub rstSource (the string containg the TSQL on which the recordset is based) is assembled by the calling routine, in this case from the Open event of the form being bound: Private Sub Form_Open(Cancel As Integer) Dim rst As ADODB.Recordset Dim strSource As String, DefaultSource as String Dim lngID As Long lngID = Forms!MyParent.CurrentID strSource = "SELECT TOP (100) PERCENT dbo.Customers.CustomerID, dbo.Customers.LegacyID, dbo.Customers.Active, dbo.Customers.TypeID, dbo.Customers.Category, " & _ "dbo.Customers.Source, dbo.Customers.CustomerName, dbo.Customers.CustAddrID, dbo.Customers.Email, dbo.Customers.TaxExempt, dbo.Customers.SalesTaxCode, " & _ "dbo.Customers.SalesTax2Code, dbo.Customers.CreditLimit, dbo.Customers.CreationDate, dbo.Customers.FirstOrder, dbo.Customers.LastOrder, " & _ "dbo.Customers.nOrders, dbo.Customers.Concurrency, dbo.Customers.LegacyLN, dbo.Addresses.AddrType, dbo.Addresses.AddrLine1, dbo.Addresses.AddrLine2, " & _ "dbo.Addresses.City, dbo.Addresses.State, dbo.Addresses.Country, dbo.Addresses.PostalCode, dbo.Addresses.PhoneLandline, dbo.Addresses.Concurrency " & _ "FROM dbo.Customers INNER JOIN " & _ "dbo.Addresses ON dbo.Customers.CustAddrID = dbo.Addresses.AddrID " strSource = strSource & "WHERE dbo.Customers.CustomerID= " & lngID With Me 'Default is Set up for editing one record If Not Nz(.RecordSource, vbNullString) = vbNullString Then If .Dirty Then .Dirty = False 'Save any changes on the form .RecordSource = vbNullString End If If rst Is Nothing Then 'Might not be first time through DefaultSource = .RecordSource Else rst.Close Set rst = Nothing End If End With Set rst = New ADODB.Recordset Call setupformrecordset(dbconn, rst, strSource) 'dbconn is a global variable With Me Set .Recordset = rst End With End Sub The recordset that is returned from setupformrecordset is fully updateable, and its .Supports property shows this. It can be edited and updated in code. The entire form, however, is read only, even though it's .AllowEdits and .AllowAdditions properties are both true. Even the fields from the right hand side (the 'many' side) cannot be edited. Removing the INNER JOIN clause from the TSQL (restricting strSource to one table) makes the form fully editable. I've verified that the TSQL includes priimary key fields from both tables, and each table includes a timestamp field for concurrency. I tried changing the .CursorType and .CursorLocation properties of the recordset to no avail. What am I doing wrong?

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• Lockless queue implementation ends up having a loop under stress

  - by Fozi

  I have lockless queues written in C in form of a linked list that contains requests from several threads posted to and handled in a single thread. After a few hours of stress I end up having the last request's next pointer pointing to itself, which creates an endless loop and locks up the handling thread. The application runs (and fails) on both Linux and Windows. I'm debugging on Windows, where my COMPARE_EXCHANGE_PTR maps to InterlockedCompareExchangePointer. This is the code that pushes a request to the head of the list, and is called from several threads: void push_request(struct request * volatile * root, struct request * request) { assert(request); do { request->next = *root; } while(COMPARE_EXCHANGE_PTR(root, request, request->next) != request->next); } This is the code that gets a request from the end of the list, and is only called by a single thread that is handling them: struct request * pop_request(struct request * volatile * root) { struct request * volatile * p; struct request * request; do { p = root; while(*p && (*p)->next) p = &(*p)->next; // <- loops here request = *p; } while(COMPARE_EXCHANGE_PTR(p, NULL, request) != request); assert(request->next == NULL); return request; } Note that I'm not using a tail pointer because I wanted to avoid the complication of having to deal with the tail pointer in push_request. However I suspect that the problem might be in the way I find the end of the list. There are several places that push a request into the queue, but they all look generaly like this: // device->requests is defined as struct request * volatile requests; struct request * request = malloc(sizeof(struct request)); if(request) { // fill out request fields push_request(&device->requests, request); sem_post(device->request_sem); } The code that handles the request is doing more than that, but in essence does this in a loop: if(sem_wait_timeout(device->request_sem, timeout) == sem_success) { struct request * request = pop_request(&device->requests); // handle request free(request); } I also just added a function that is checking the list for duplicates before and after each operation, but I'm afraid that this check will change the timing so that I will never encounter the point where it fails. (I'm waiting for it to break as I'm writing this.) When I break the hanging program the handler thread loops in pop_request at the marked position. I have a valid list of one or more requests and the last one's next pointer points to itself. The request queues are usually short, I've never seen more then 10, and only 1 and 3 the two times I could take a look at this failure in the debugger. I thought this through as much as I could and I came to the conclusion that I should never be able to end up with a loop in my list unless I push the same request twice. I'm quite sure that this never happens. I'm also fairly sure (although not completely) that it's not the ABA problem. I know that I might pop more than one request at the same time, but I believe this is irrelevant here, and I've never seen it happening. (I'll fix this as well) I thought long and hard about how I can break my function, but I don't see a way to end up with a loop. So the question is: Can someone see a way how this can break? Can someone prove that this can not? Eventually I will solve this (maybe by using a tail pointer or some other solution - locking would be a problem because the threads that post should not be locked, I do have a RW lock at hand though) but I would like to make sure that changing the list actually solves my problem (as opposed to makes it just less likely because of different timing).

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• Processing Kinect v2 Color Streams in Parallel

  - by Chris Gardner

  Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2014/08/20/processing-kinect-v2-color-streams-in-parallel.aspxProcessing Kinect v2 Color Streams in Parallel I've really been enjoying being a part of the Kinect for Windows Developer's Preview. The new hardware has some really impressive capabilities. However, with great power comes great system specs. Unfortunately, my little laptop that could is not 100% up to the task; I've had to get a little creative. The most disappointing thing I've run into is that I can't always cleanly display the color camera stream in managed code. I managed to strip the code down to what I believe is the bear minimum: using( ColorFrame _ColorFrame = e.FrameReference.AcquireFrame() ) { if( null == _ColorFrame ) return;   BitmapToDisplay.Lock(); _ColorFrame.CopyConvertedFrameDataToIntPtr( BitmapToDisplay.BackBuffer, Convert.ToUInt32( BitmapToDisplay.BackBufferStride * BitmapToDisplay.PixelHeight ), ColorImageFormat.Bgra ); BitmapToDisplay.AddDirtyRect( new Int32Rect( 0, 0, _ColorFrame.FrameDescription.Width, _ColorFrame.FrameDescription.Height ) ); BitmapToDisplay.Unlock(); } With this snippet, I'm placing the converted Bgra32 color stream directly on the BackBuffer of the WriteableBitmap. This gives me pretty smooth playback, but I still get the occasional freeze for half a second. After a bit of profiling, I discovered there were a few problems. The first problem is the size of the buffer along with the conversion on the buffer. At this time, the raw image format of the data from the Kinect is Yuy2. This is great for direct video processing. It would be ideal if I had a WriteableVideo object in WPF. However, this is not the case. Further digging led me to the real problem. It appears that the SDK is converting the input serially. Let's think about this for a second. The color camera is a 1080p camera. As we should all know, this give us a native resolution of 1920 x 1080. This produces 2,073,600 pixels. Yuy2 uses 4 bytes per 2 pixel, for a buffer size of 4,147,200 bytes. Bgra32 uses 4 bytes per pixel, for a buffer size of 8,294,400 bytes. The SDK appears to be doing this on one thread. I started wondering if I chould do this better myself. I mean, I have 8 cores in my system. Why can't I use them all? The first problem is converting a Yuy2 frame into a Bgra32 frame. It is NOT trivial. I spent a day of research of just how to do this. In the end, I didn't even produce the best algorithm possible, but it did work. After I managed to get that to work, I knew my next step was the get the conversion operation off the UI Thread. This was a simple process of throwing the work into a Task. Of course, this meant I had to marshal the final write to the WriteableBitmap back to the UI thread. Finally, I needed to vectorize the operation so I could run it safely in parallel. This was, mercifully, not quite as hard as I thought it would be. I had my loop return an index to a pair of pixels. From there, I had to tell the loop to do everything for this pair of pixels. If you're wondering why I did it for pairs of pixels, look back above at the specification for the Yuy2 format. I won't go into full detail on why each 4 bytes contains 2 pixels of information, but rest assured that there is a reason why the format is described in that way. The first working attempt at this algorithm successfully turned my poor laptop into a space heater. I very quickly brought and maintained all 8 cores up to about 97% usage. That's when I remembered that obscure option in the Task Parallel Library where you could limit the amount of parallelism used. After a little trial and error, I discovered 4 parallel tasks was enough for most cases. This yielded the follow code: private byte ClipToByte( int p_ValueToClip ) { return Convert.ToByte( ( p_ValueToClip < byte.MinValue ) ? byte.MinValue : ( ( p_ValueToClip > byte.MaxValue ) ? byte.MaxValue : p_ValueToClip ) ); }   private void ColorFrameArrived( object sender, ColorFrameArrivedEventArgs e ) { if( null == e.FrameReference ) return;   // If you do not dispose of the frame, you never get another one... using( ColorFrame _ColorFrame = e.FrameReference.AcquireFrame() ) { if( null == _ColorFrame ) return;   byte[] _InputImage = new byte[_ColorFrame.FrameDescription.LengthInPixels * _ColorFrame.FrameDescription.BytesPerPixel]; byte[] _OutputImage = new byte[BitmapToDisplay.BackBufferStride * BitmapToDisplay.PixelHeight]; _ColorFrame.CopyRawFrameDataToArray( _InputImage );   Task.Factory.StartNew( () => { ParallelOptions _ParallelOptions = new ParallelOptions(); _ParallelOptions.MaxDegreeOfParallelism = 4;   Parallel.For( 0, Sensor.ColorFrameSource.FrameDescription.LengthInPixels / 2, _ParallelOptions, ( _Index ) => { // See http://msdn.microsoft.com/en-us/library/windows/desktop/dd206750(v=vs.85).aspx int _Y0 = _InputImage[( _Index << 2 ) + 0] - 16; int _U = _InputImage[( _Index << 2 ) + 1] - 128; int _Y1 = _InputImage[( _Index << 2 ) + 2] - 16; int _V = _InputImage[( _Index << 2 ) + 3] - 128;   byte _R = ClipToByte( ( 298 * _Y0 + 409 * _V + 128 ) >> 8 ); byte _G = ClipToByte( ( 298 * _Y0 - 100 * _U - 208 * _V + 128 ) >> 8 ); byte _B = ClipToByte( ( 298 * _Y0 + 516 * _U + 128 ) >> 8 );   _OutputImage[( _Index << 3 ) + 0] = _B; _OutputImage[( _Index << 3 ) + 1] = _G; _OutputImage[( _Index << 3 ) + 2] = _R; _OutputImage[( _Index << 3 ) + 3] = 0xFF; // A   _R = ClipToByte( ( 298 * _Y1 + 409 * _V + 128 ) >> 8 ); _G = ClipToByte( ( 298 * _Y1 - 100 * _U - 208 * _V + 128 ) >> 8 ); _B = ClipToByte( ( 298 * _Y1 + 516 * _U + 128 ) >> 8 );   _OutputImage[( _Index << 3 ) + 4] = _B; _OutputImage[( _Index << 3 ) + 5] = _G; _OutputImage[( _Index << 3 ) + 6] = _R; _OutputImage[( _Index << 3 ) + 7] = 0xFF; } );   Application.Current.Dispatcher.Invoke( () => { BitmapToDisplay.WritePixels( new Int32Rect( 0, 0, Sensor.ColorFrameSource.FrameDescription.Width, Sensor.ColorFrameSource.FrameDescription.Height ), _OutputImage, BitmapToDisplay.BackBufferStride, 0 ); } ); } ); } } This seemed to yield a results I wanted, but there was still the occasional stutter. This lead to what I realized was the second problem. There is a race condition between the UI Thread and me locking the WriteableBitmap so I can write the next frame. Again, I'm writing approximately 8MB to the back buffer. Then, I started thinking I could cheat. The Kinect is running at 30 frames per second. The WPF UI Thread runs at 60 frames per second. This made me not feel bad about exploiting the Composition Thread. I moved the bulk of the code from the FrameArrived handler into CompositionTarget.Rendering. Once I was in there, I polled from a frame, and rendered it if it existed. Since, in theory, I'm only killing the Composition Thread every other hit, I decided I was ok with this for cases where silky smooth video performance REALLY mattered. This ode looked like this: private byte ClipToByte( int p_ValueToClip ) { return Convert.ToByte( ( p_ValueToClip < byte.MinValue ) ? byte.MinValue : ( ( p_ValueToClip > byte.MaxValue ) ? byte.MaxValue : p_ValueToClip ) ); }   void CompositionTarget_Rendering( object sender, EventArgs e ) { using( ColorFrame _ColorFrame = FrameReader.AcquireLatestFrame() ) { if( null == _ColorFrame ) return;   byte[] _InputImage = new byte[_ColorFrame.FrameDescription.LengthInPixels * _ColorFrame.FrameDescription.BytesPerPixel]; byte[] _OutputImage = new byte[BitmapToDisplay.BackBufferStride * BitmapToDisplay.PixelHeight]; _ColorFrame.CopyRawFrameDataToArray( _InputImage );   ParallelOptions _ParallelOptions = new ParallelOptions(); _ParallelOptions.MaxDegreeOfParallelism = 4;   Parallel.For( 0, Sensor.ColorFrameSource.FrameDescription.LengthInPixels / 2, _ParallelOptions, ( _Index ) => { // See http://msdn.microsoft.com/en-us/library/windows/desktop/dd206750(v=vs.85).aspx int _Y0 = _InputImage[( _Index << 2 ) + 0] - 16; int _U = _InputImage[( _Index << 2 ) + 1] - 128; int _Y1 = _InputImage[( _Index << 2 ) + 2] - 16; int _V = _InputImage[( _Index << 2 ) + 3] - 128;   byte _R = ClipToByte( ( 298 * _Y0 + 409 * _V + 128 ) >> 8 ); byte _G = ClipToByte( ( 298 * _Y0 - 100 * _U - 208 * _V + 128 ) >> 8 ); byte _B = ClipToByte( ( 298 * _Y0 + 516 * _U + 128 ) >> 8 );   _OutputImage[( _Index << 3 ) + 0] = _B; _OutputImage[( _Index << 3 ) + 1] = _G; _OutputImage[( _Index << 3 ) + 2] = _R; _OutputImage[( _Index << 3 ) + 3] = 0xFF; // A   _R = ClipToByte( ( 298 * _Y1 + 409 * _V + 128 ) >> 8 ); _G = ClipToByte( ( 298 * _Y1 - 100 * _U - 208 * _V + 128 ) >> 8 ); _B = ClipToByte( ( 298 * _Y1 + 516 * _U + 128 ) >> 8 );   _OutputImage[( _Index << 3 ) + 4] = _B; _OutputImage[( _Index << 3 ) + 5] = _G; _OutputImage[( _Index << 3 ) + 6] = _R; _OutputImage[( _Index << 3 ) + 7] = 0xFF; } );   BitmapToDisplay.WritePixels( new Int32Rect( 0, 0, Sensor.ColorFrameSource.FrameDescription.Width, Sensor.ColorFrameSource.FrameDescription.Height ), _OutputImage, BitmapToDisplay.BackBufferStride, 0 ); } }

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• CodePlex Daily Summary for Thursday, May 29, 2014

  CodePlex Daily Summary for Thursday, May 29, 2014Popular ReleasesQuickMon: Version 3.13: 1. Adding an Audio/sound notifier that can be used to simply draw attention to the application of a warning pr error state is returned by a collector. 2. Adding a property for Notifiers so it can be set to 'Attended', 'Unattended' or 'Both' modes. 3. Adding a WCF method to remote agent host so the version can be checked remotely. 4. Adding some 'Sample' monitor packs to installer. Note: this release and the next release (3.14 aka Pie release) will have some breaking changes and will be incom...fnr.exe - Find And Replace Tool: 1.7: Bug fixes Refactored logic for encoding text values to command line to handle common edge cases where find/replace operation works in GUI but not in command line Fix for bug where selection in Encoding drop down was different when generating command line in some cases. It was reported in: https://findandreplace.codeplex.com/workitem/34 Fix for "Backslash inserted before dot in replacement text" reported here: https://findandreplace.codeplex.com/discussions/541024 Fix for finding replacing...VG-Ripper & PG-Ripper: VG-Ripper 2.9.59: changes NEW: Added Support for 'GokoImage.com' links NEW: Added Support for 'ViperII.com' links NEW: Added Support for 'PixxxView.com' links NEW: Added Support for 'ImgRex.com' links NEW: Added Support for 'PixLiv.com' links NEW: Added Support for 'imgsee.me' links NEW: Added Support for 'ImgS.it' linksXsemmel - XML Editor and Viewer: 29-MAY-2014: WINDOWS XP IS NO LONGER SUPPORTED If you need support for WinXP, download release 15-MAR-2014 instead. FIX: Some minor issues NEW: Better visualisation of validation issues NEW: Printing CHG: Disabled Jumplist CHG: updated to .net 4.5, WinXP NO LONGER SUPPORTEDSPART (SharePoint Admin & Reporting Tool): Installation Kit V1.1: Installation Kit SPART V1.1 This release covers, • Site Size • Count - Sites, Site Collection, Document • Site collection quota information • Site/Web apps / Site collection permission which seeks URL as input/ • Last content change for sites which displays the time stampPerformance Analyzer for Microsoft Dynamics: DynamicsPerf 1.20: Version 1.20 Improved performance in PERFHOURLYROWDATA_VW Fixed error handling encrypted triggers Added logic ACTIVITYMONITORVW to handle Context_Info for Dynamics AX 2012 and above with this flag set on AOS Added logic to optional blocking to handle Context_Info for Dynamics AX 2012 and above with this flag set on AOS Added additional queries for investigating blocking Added logic to collect Baseline capture data (NOTE: QUERY_STATS table has entire procedure cache for that db during...Toolbox for Dynamics CRM 2011/2013: XrmToolBox (v1.2014.5.28): XrmToolbox improvement XrmToolBox updates (v1.2014.5.28)Fix connecting to a connection with custom authentication without saved password Tools improvement New tool!Solution Components Mover (v1.2014.5.22) Transfer solution components from one solution to another one Import/Export NN relationships (v1.2014.3.7) Allows you to import and export many to many relationships Tools updatesAttribute Bulk Updater (v1.2014.5.28) Audit Center (v1.2014.5.28) View Layout Replicator (v1.2014.5.28) Scrip...Microsoft Ajax Minifier: Microsoft Ajax Minifier 5.10: Fix for Issue #20875 - echo switch doesn't work for CSS CSS should honor the SASS source-file comments JS should allow multi-line comment directivesClosedXML - The easy way to OpenXML: ClosedXML 0.71.1: More performance improvements. It's faster and consumes less memory.Dynamics CRM Rich UX: RichUX Managed Solution File v0.4: Added format type attribute so icons, CSS and colors may be defined by the retrieved entity record. Also added samples in documentation on setting up FetchXML and tabs. Only for demo / experimenting. Do not use in production without extensive testing. Please help make this package better by reporting all issues.Fluentx: Fluentx v1.4.0: Added object to object mapper, added new NotIn extention method, and added documentation to library with fluentx.xmlVK.NET - Vkontakte API for .NET: VkNet 1.0.5: ?????????? ????? ??????.Kartris E-commerce: Kartris v2.6002: Minor release: Double check that Logins_GetList sproc is present, sometimes seems to get missed earlier if upgrading which can give error when viewing logins page Added CSV and TXT export option; this is not Google Products compatible, but can give a good base for creating a file for some other systems such as Amazon Fixed some minor combination and options issues to improve interface back and front Turn bitcoin and some other gateways off by default Minor CSS changes Fixed currenc...SimCityPak: SimCityPak 0.3.1.0: Main New Features: Fixed Importing of Instance Names (get rid of the Dutch translations) Added advanced editor for Decal Dictionaries Added possibility to import .PNG to generate new decals Added advanced editor for Path display entriesTiny Deduplicator: Tiny Deduplicator 1.0.1.0: Increased version number to 1.0.1.0 Moved all options to a separate 'Options' dialog window. Allows the user to specify a selection strategy which will help when dealing with large numbers of duplicate files. Available options are "None," "Keep First," and "Keep Last"SEToolbox: SEToolbox 01.031.009 Release 1: Added mirroring of ConveyorTubeCurved. Updated Ship cube rotation to rotate ship back to original location (cubes are reoriented but ship appears no different to outsider), and to rotate Grouped items. Repair now fixes the loss of Grouped controls due to changes in Space Engineers 01.030. Added export asteroids. Rejoin ships will merge grouping and conveyor systems (even though broken ships currently only maintain the Grouping on one part of the ship). Installation of this version wi...Player Framework by Microsoft: Player Framework for Windows and WP v2.0: Support for new Universal and Windows Phone 8.1 projects for both Xaml and JavaScript projects. See a detailed list of improvements, breaking changes and a general overview of version 2 ADDITIONAL DOWNLOADSSmooth Streaming Client SDK for Windows 8 Applications Smooth Streaming Client SDK for Windows 8.1 Applications Smooth Streaming Client SDK for Windows Phone 8.1 Applications Microsoft PlayReady Client SDK for Windows 8 Applications Microsoft PlayReady Client SDK for Windows 8.1 Applicat...TerraMap (Terraria World Map Viewer): TerraMap 1.0.6: Added support for the new Terraria v1.2.4 update. New items, walls, and tiles Added the ability to select multiple highlighted block types. Added a dynamic, interactive highlight opacity slider, making it easier to find highlighted tiles with dark colors (and fixed blurriness from 1.0.5 alpha). Added ability to find Enchanted Swords (in the stone) and Water Bolt books Fixed Issue 35206: Hightlight/Find doesn't work for Demon Altars Fixed finding Demon Hearts/Shadow Orbs Fixed inst...DotNet.Highcharts: DotNet.Highcharts 4.0 with Examples: DotNet.Highcharts 4.0 Tested and adapted to the latest version of Highcharts 4.0.1 Added new chart type: Heatmap Added new type PointPlacement which represents enumeration or number for the padding of the X axis. Changed target framework from .NET Framework 4 to .NET Framework 4.5. Closed issues: 974: Add 'overflow' property to PlotOptionsColumnDataLabels class 997: Split container from JS 1006: Series/Categories with numeric names don't render DotNet.Highcharts.Samples Updated s...Extended WPF Toolkit™ Community Edition: Extended WPF Toolkit - 2.2.0: What's new in v2.2.0 Community Edition? Improvements and bug fixes Two new free controls: TimeSpanUpDown and RangeSlider 15 bug fixes and improvements (See the complete list of improvements in v2.2.0). Updated Live Explorer app available online as a Click Once app. Try it now! Want an easier way to install the Extended WPF Toolkit? The Extended WPF Toolkit is available on Nuget. .NET Framework notes:Requires .NET Framework 4.0 or 4.5. A build for .NET 3.5 is available but also requires ...New Projects2112110026: OOP- Lê Th? Xuân HuongASP.Net Controls Extended: ASP controls' look modified and behavior extended.Audio Tools: The project is intended to capture common knowledge about popular audio file formats and related stuff.Dnn Bootstrap Helpers: Dnn Bootstrap helpers ( Tabs, Accordion & Carousel )itouch - JS touch library for browser: this project hosts a JavaScript library which enables you to handle user's touch gestures like swiping, pinching, clicking on your web app cross platform/deviceMySQL Powershell Library: This PowerShell Module attempt to provide a convenient methods for working with MySQL. It make use of the Oracle MySQL .Net connector version 6.8.3Performance Analyzer for Microsoft Dynamics: Performance Analyzer for Microsoft Dynamics is a toolset developed by Premier Field Engineering at Microsoft for resolving performance issues with Dynamics PRISA NEW: LIBRERIA PRISAQFix Rx: This project aims at enabling Rx based programming for Quick FIX / n API by pushing events to Quick FIX / n API and subscribing to to event feeds from the API.Riccsson.System a C# .NET library for C++: Riccsson.System is a C#-like library for C++ with support of Events, Delegates, Properties, Threading, Locking, and more. For easier to port C# libraries to C++SusicoTrader: A F# / C# based trading API with connections to IB and QuickFix/n API. TestCodePlex: testTP2Academia.net: .net projectoTypeScriptTD: TypeScriptTD is a tower defense game written in TypeScript with help of the Phaser game engine. It is a port of ScriptTD http://scripttd.codeplex.com/Universal Autosave: Universal Autosave (UA) is extension for DNN Platform. It allows easy and fast to configure autosave functionality for any form/control without any coding.WeatherView: A universal Windows app written in C# demonstrating geolocation and webservices.

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• Suggestions for lightweight, thread-safe scheduler

  - by nirvanai

  I am trying to write a round-robin scheduler for lightweight threads (fibers). It must scale to handle as many concurrently-scheduled fibers as possible. I also need to be able to schedule fibers from threads other than the one the run loop is on, and preferably unschedule them from arbitrary threads as well (though I could live with only being able to unschedule them from the run loop). My current idea is to have a circular doubly-linked list, where each fiber is a node and the scheduler holds a reference to the current node. This is what I have so far: using Interlocked = System.Threading.Interlocked; public class Thread { internal Future current_fiber; public void RunLoop () { while (true) { var fiber = current_fiber; if (fiber == null) { // block the thread until a fiber is scheduled continue; } if (fiber.Fulfilled) fiber.Unschedule (); else fiber.Resume (); //if (current_fiber == fiber) current_fiber = fiber.next; Interlocked.CompareExchange<Future> (ref current_fiber, fiber.next, fiber); } } } public abstract class Future { public bool Fulfilled { get; protected set; } internal Future previous, next; // this must be thread-safe // it inserts this node before thread.current_fiber // (getting the exact position doesn't matter, as long as the // chosen nodes haven't been unscheduled) public void Schedule (Thread thread) { next = this; // maintain circularity, even if this is the only node previous = this; try_again: var current = Interlocked.CompareExchange<Future> (ref thread.current_fiber, this, null); if (current == null) return; var target = current.previous; while (target == null) { // current was unscheduled; negotiate for new current_fiber var potential = current.next; var actual = Interlocked.CompareExchange<Future> (ref thread.current_fiber, potential, current); current = (actual == current? potential : actual); if (current == null) goto try_again; target = current.previous; } // I would lock "current" and "target" at this point. // How can I do this w/o risk of deadlock? next = current; previous = target; target.next = this; current.previous = this; } // this would ideally be thread-safe public void Unschedule () { var prev = previous; if (prev == null) { // already unscheduled return; } previous = null; if (next == this) { next = null; return; } // Again, I would lock "prev" and "next" here // How can I do this w/o risk of deadlock? prev.next = next; next.previous = prev; } public abstract void Resume (); } As you can see, my sticking point is that I cannot ensure the order of locking, so I can't lock more than one node without risking deadlock. Or can I? I don't want to have a global lock on the Thread object, since the amount of lock contention would be extreme. Plus, I don't especially care about insertion position, so if I lock each node separately then Schedule() could use something like Monitor.TryEnter and just keep walking the list until it finds an unlocked node. Overall, I'm not invested in any particular implementation, as long as it meets the requirements I've mentioned. Any ideas would be greatly appreciated. Thanks! P.S- For the curious, this is for an open source project I'm starting at http://github.com/nirvanai/Cirrus

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• What is New in ASP.NET 4.0 Code Access Security

  - by Xiaohong

  ASP.NET Code Access Security (CAS) is a feature that helps protect server applications on hosting multiple Web sites, ASP.NET lets you assign a configurable trust level that corresponds to a predefined set of permissions. ASP.NET has predefined ASP.NET Trust Levels and Policy Files that you can assign to applications, you also can assign custom trust level and policy files. Most web hosting companies run ASP.NET applications in Medium Trust to prevent that one website affect or harm another site etc. As .NET Framework's Code Access Security model has evolved, ASP.NET 4.0 Code Access Security also has introduced several changes and improvements. The main change in ASP.NET 4.0 CAS In ASP.NET v4.0 partial trust applications, application domain can have a default partial trust permission set as opposed to being full-trust, the permission set name is defined in the <trust /> new attribute permissionSetName that is used to initialize the application domain . By default, the PermissionSetName attribute value is "ASP.Net" which is the name of the permission set you can find in all predefined partial trust configuration files. <trust level="Something" permissionSetName="ASP.Net" /> This is ASP.NET 4.0 new CAS model. For compatibility ASP.NET 4.0 also support legacy CAS model where application domain still has full trust permission set. You can specify new legacyCasModel attribute on the <trust /> element to indicate whether the legacy CAS model is enabled. By default legacyCasModel is false which means that new 4.0 CAS model is the default. <trust level="Something" legacyCasModel="true|false" /> In .Net FX 4.0 Config directory, there are two set of predefined partial trust config files for each new CAS model and legacy CAS model, trust config files with name legacy.XYZ.config are for legacy CAS model: New CAS model: Legacy CAS model: web_hightrust.config legacy.web_hightrust.config web_mediumtrust.config legacy.web_mediumtrust.config web_lowtrust.config legacy.web_lowtrust.config web_minimaltrust.config legacy.web_minimaltrust.config   The figure below shows in ASP.NET 4.0 new CAS model what permission set to grant to code for partial trust application using predefined partial trust levels and policy files:    There also some benefits that comes with the new CAS model: You can lock down a machine by making all managed code no-execute by default (e.g. setting the MyComputer zone to have no managed execution code permissions), it should still be possible to configure ASP.NET web applications to run as either full-trust or partial trust. UNC share doesn’t require full trust with CASPOL at machine-level CAS policy. Side effect that comes with the new CAS model: processRequestInApplicationTrust attribute is deprecated  in new CAS model since application domain always has partial trust permission set in new CAS model.   In ASP.NET 4.0 legacy CAS model or ASP.NET 2.0 CAS model, even though you assign partial trust level to a application but the application domain still has full trust permission set. The figure below shows in ASP.NET 4.0 legacy CAS model (or ASP.NET 2.0 CAS model) what permission set to grant to code for partial trust application using predefined partial trust levels and policy files:     What $AppDirUrl$, $CodeGen$, $Gac$ represents: $AppDirUrl$ The application's virtual root directory. This allows permissions to be applied to code that is located in the application's bin directory. For example, if a virtual directory is mapped to C:\YourWebApp, then $AppDirUrl$ would equate to C:\YourWebApp. $CodeGen$ The directory that contains dynamically generated assemblies (for example, the result of .aspx page compiles). This can be configured on a per application basis and defaults to %windir%\Microsoft.NET\Framework\{version}\Temporary ASP.NET Files. $CodeGen$ allows permissions to be applied to dynamically generated assemblies. $Gac$ Any assembly that is installed in the computer's global assembly cache (GAC). This allows permissions to be granted to strong named assemblies loaded from the GAC by the Web application.   The new customization of CAS Policy in ASP.NET 4.0 new CAS model 1. Define which named permission set in partial trust configuration files By default the permission set that will be assigned at application domain initialization time is the named "ASP.Net" permission set found in all predefined partial trust configuration files. However ASP.NET 4.0 allows you set PermissionSetName attribute to define which named permission set in a partial trust configuration file should be the one used to initialize an application domain. Example: add "ASP.Net_2" named permission set in partial trust configuration file: <PermissionSet class="NamedPermissionSet" version="1" Name="ASP.Net_2"> <IPermission class="FileIOPermission" version="1" Read="$AppDir$" PathDiscovery="$AppDir$" /> <IPermission class="ReflectionPermission" version="1" Flags ="RestrictedMemberAccess" /> <IPermission class="SecurityPermission " version="1" Flags ="Execution, ControlThread, ControlPrincipal, RemotingConfiguration" /></PermissionSet> Then you can use "ASP.Net_2" named permission set for the application domain permission set: <trust level="Something" legacyCasModel="false" permissionSetName="ASP.Net_2" /> 2. Define a custom set of Full Trust Assemblies for an application By using the new fullTrustAssemblies element to configure a set of Full Trust Assemblies for an application, you can modify set of partial trust assemblies to full trust at the machine, site or application level. The configuration definition is shown below: <fullTrustAssemblies> <add assemblyName="MyAssembly" version="1.1.2.3" publicKey="hex_char_representation_of_key_blob" /></fullTrustAssemblies> 3. Define <CodeGroup /> policy in partial trust configuration files ASP.NET 4.0 new CAS model will retain the ability for developers to optionally define <CodeGroup />with membership conditions and assigned permission sets. The specific restriction in ASP.NET 4.0 new CAS model though will be that the results of evaluating custom policies can only result in one of two outcomes: either an assembly is granted full trust, or an assembly is granted the partial trust permission set currently associated with the running application domain. It will not be possible to use custom policies to create additional custom partial trust permission sets. When parsing the partial trust configuration file: Any assemblies that match to code groups associated with "PermissionSet='FullTrust'" will run at full trust. Any assemblies that match to code groups associated with "PermissionSet='Nothing'" will result in a PolicyError being thrown from the CLR. This is acceptable since it provides administrators with a way to do a blanket-deny of managed code followed by selectively defining policy in a <CodeGroup /> that re-adds assemblies that would be allowed to run. Any assemblies that match to code groups associated with other permissions sets will be interpreted to mean the assembly should run at the permission set of the appdomain. This means that even though syntactically a developer could define additional "flavors" of partial trust in an ASP.NET partial trust configuration file, those "flavors" will always be ignored. Example: defines full trust in <CodeGroup /> for my strong named assemblies in partial trust config files: <CodeGroup class="FirstMatchCodeGroup" version="1" PermissionSetName="Nothing"> <IMembershipCondition    class="AllMembershipCondition"    version="1" /> <CodeGroup    class="UnionCodeGroup"    version="1"    PermissionSetName="FullTrust"    Name="My_Strong_Name"    Description="This code group grants code signed full trust. "> <IMembershipCondition      class="StrongNameMembershipCondition" version="1"       PublicKeyBlob="hex_char_representation_of_key_blob" /> </CodeGroup> <CodeGroup   class="UnionCodeGroup" version="1" PermissionSetName="ASP.Net">   <IMembershipCondition class="UrlMembershipCondition" version="1" Url="$AppDirUrl$/*" /> </CodeGroup> <CodeGroup class="UnionCodeGroup" version="1" PermissionSetName="ASP.Net">   <IMembershipCondition class="UrlMembershipCondition" version="1" Url="$CodeGen$/*"   /> </CodeGroup></CodeGroup>   4. Customize CAS policy at runtime in ASP.NET 4.0 new CAS model ASP.NET 4.0 new CAS model allows to customize CAS policy at runtime by using custom HostSecurityPolicyResolver that overrides the ASP.NET code access security policy. Example: use custom host security policy resolver to resolve partial trust web application bin folder MyTrustedAssembly.dll to full trust at runtime: You can create a custom host security policy resolver and compile it to assembly MyCustomResolver.dll with strong name enabled and deploy in GAC: public class MyCustomResolver : HostSecurityPolicyResolver{ public override HostSecurityPolicyResults ResolvePolicy(Evidence evidence) { IEnumerator hostEvidence = evidence.GetHostEnumerator(); while (hostEvidence.MoveNext()) { object hostEvidenceObject = hostEvidence.Current; if (hostEvidenceObject is System.Security.Policy.Url) { string assemblyName = hostEvidenceObject.ToString(); if (assemblyName.Contains(“MyTrustedAssembly.dll”) return HostSecurityPolicyResult.FullTrust; } } //default fall-through return HostSecurityPolicyResult.DefaultPolicy; }} Because ASP.NET accesses the custom HostSecurityPolicyResolver during application domain initialization, and a custom policy resolver requires full trust, you also can add a custom policy resolver in <fullTrustAssemblies /> , or deploy in the GAC. You also need configure a custom HostSecurityPolicyResolver instance by adding the HostSecurityPolicyResolverType attribute in the <trust /> element: <trust level="Something" legacyCasModel="false" hostSecurityPolicyResolverType="MyCustomResolver, MyCustomResolver" permissionSetName="ASP.Net" />   Note: If an assembly policy define in <CodeGroup/> and also in hostSecurityPolicyResolverType, hostSecurityPolicyResolverType will win. If an assembly added in <fullTrustAssemblies/> then the assembly has full trust no matter what policy in <CodeGroup/> or in hostSecurityPolicyResolverType.   Other changes in ASP.NET 4.0 CAS Use the new transparency model introduced in .Net Framework 4.0 Change in dynamically compiled code generated assemblies by ASP.NET: In new CAS model they will be marked as security transparent level2 to use Framework 4.0 security transparent rule that means partial trust code is treated as completely Transparent and it is more strict enforcement. In legacy CAS model they will be marked as security transparent level1 to use Framework 2.0 security transparent rule for compatibility. Most of ASP.NET products runtime assemblies are also changed to be marked as security transparent level2 to switch to SecurityTransparent code by default unless SecurityCritical or SecuritySafeCritical attribute specified. You also can look at Security Changes in the .NET Framework 4 for more information about these security attributes. Support conditional APTCA If an assembly is marked with the Conditional APTCA attribute to allow partially trusted callers, and if you want to make the assembly both visible and accessible to partial-trust code in your web application, you must add a reference to the assembly in the partialTrustVisibleAssemblies section: <partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" />/partialTrustVisibleAssemblies>   Most of ASP.NET products runtime assemblies are also changed to be marked as conditional APTCA to prevent use of ASP.NET APIs in partial trust environments such as Winforms or WPF UI controls hosted in Internet Explorer.   Differences between ASP.NET new CAS model and legacy CAS model: Here list some differences between ASP.NET new CAS model and legacy CAS model ASP.NET 4.0 legacy CAS model  : Asp.net partial trust appdomains have full trust permission Multiple different permission sets in a single appdomain are allowed in ASP.NET partial trust configuration files Code groups Machine CAS policy is honored processRequestInApplicationTrust attribute is still honored    New configuration setting for legacy model: <trust level="Something" legacyCASModel="true" ></trust><partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" /></partialTrustVisibleAssemblies>   ASP.NET 4.0 new CAS model: ASP.NET will now run in homogeneous application domains. Only full trust or the app-domain's partial trust grant set, are allowable permission sets. It is no longer possible to define arbitrary permission sets that get assigned to different assemblies. If an application currently depends on fine-tuning the partial trust permission set using the ASP.NET partial trust configuration file, this will no longer be possible. processRequestInApplicationTrust attribute is deprecated Dynamically compiled assemblies output by ASP.NET build providers will be updated to explicitly mark assemblies as transparent. ASP.NET partial trust grant sets will be independent from any enterprise, machine, or user CAS policy levels. A simplified model for locking down web servers that only allows trusted managed web applications to run. Machine policy used to always grant full-trust to managed code (based on membership conditions) can instead be configured using the new ASP.NET 4.0 full-trust assembly configuration section. The full-trust assembly configuration section requires explicitly listing each assembly as opposed to using membership conditions. Alternatively, the membership condition(s) used in machine policy can instead be re-defined in a <CodeGroup /> within ASP.NET's partial trust configuration file to grant full-trust.   New configuration setting for new model: <trust level="Something" legacyCASModel="false" permissionSetName="ASP.Net" hostSecurityPolicyResolverType=".NET type string" ></trust><fullTrustAssemblies> <add assemblyName=”MyAssembly” version=”1.0.0.0” publicKey="hex_char_representation_of_key_blob" /></fullTrustAssemblies><partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" /></partialTrustVisibleAssemblies>     Hope this post is helpful to better understand the ASP.Net 4.0 CAS. Xiaohong Tang ASP.NET QA Team

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• Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 3

  - by Tarun Arora

  Welcome back once again, in Part 1 of Load and Web Performance Testing using Visual Studio 2010 I talked about why Performance Testing the application is important, the test tools available in Visual Studio Ultimate 2010 and various test rig topologies, in Part 2 of Load and Web Performance Testing using Visual Studio 2010 I discussed the details of web performance & load tests as well as why it’s important to follow a goal based pattern while performance testing your application. In part 3 I’ll be discussing Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, Asp.net Profiler and some closing thoughts. Test Results – I see some creepy worms! In Part 2 we put together a web performance test and a load test, lets run the test to see load test to see how the Web site responds to the load simulation. While the load test is running you will be able to see close to real time analysis in the Load Test Analyser window. You can use the Load Test Analyser to conduct load test analysis in three ways: Monitor a running load test - A condensed set of the performance counter data is maintained in memory. To prevent the results memory requirements from growing unbounded, up to 200 samples for each performance counter are maintained. This includes 100 evenly spaced samples that span the current elapsed time of the run and the most recent 100 samples.         After the load test run is completed - The test controller spools all collected performance counter data to a database while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes. The performance data for a completed test is loaded from the database and analysed by the Load Test Analyser. Below you can see a screen shot of the summary view, this provides key results in a format that is compact and easy to read. You can also print the load test summary, this is generated after the test has completed or been stopped.         Analyse the load test results of a previously run load test – We’ll see this in the section where i discuss comparison between two test runs. The performance counters can be plotted on the graphs. You also have the option to highlight a selected part of the test and view details, drill down to the user activity chart where you can hover over to see more details of the test run.   Generate Report => Test Run Comparisons The level of reports you can generate using the Load Test Analyser is astonishing. You have the option to create excel reports and conduct side by side analysis of two test results or to track trend analysis. The tools also allows you to export the graph data either to MS Excel or to a CSV file. You can view the ASP.NET profiler report to conduct further analysis as well. View Data and Diagnostic Attachments opens the Choose Diagnostic Data Adapter Attachment dialog box to select an adapter to analyse the result type. For example, you can select an IntelliTrace adapter, click OK and open the IntelliTrace summary for the test agent that was used in the load test.   Compare results This creates a set of reports that compares the data from two load test results using tables and bar charts. I have taken these screen shots from the MSDN documentation, I would highly recommend exploring the wealth of knowledge available on MSDN. Leaving Thoughts While load testing the application with an excessive load for a longer duration of time, i managed to bring the IIS to its knees by piling up a huge queue of requests waiting to be processed. This clearly means that the IIS had run out of threads as all the threads were busy processing existing request, one easy way of fixing this is by increasing the default number of allocated threads, but this might escalate the problem. The better suggestion is to try and drill down to the actual root cause of the problem. When ever the garbage collection runs it stops processing any pages so all requests that come in during that period are queued up, but realistically the garbage collection completes in fraction of a a second. To understand this better lets look at the .net heap, it is divided into large heap and small heap, anything greater than 85kB in size will be allocated to the Large object heap, the Large object heap is non compacting and remember large objects are expensive to move around, so if you are allocating something in the large object heap, make sure that you really need it! The small object heap on the other hand is divided into generations, so all objects that are supposed to be short-lived are suppose to live in Gen-0 and the long living objects eventually move to Gen-2 as garbage collection goes through.  As you can see in the picture below all < 85 KB size objects are first assigned to Gen-0, when Gen-0 fills up and a new object comes in and finds Gen-0 full, the garbage collection process is started, the process checks for all the dead objects and assigns them as the valid candidate for deletion to free up memory and promotes all the remaining objects in Gen-0 to Gen-1. So in the future when ever you clean up Gen-1 you have to clean up Gen-0 as well. When you fill up Gen – 0 again, all of Gen – 1 dead objects are drenched and rest are moved to Gen-2 and Gen-0 objects are moved to Gen-1 to free up Gen-0, but by this time your Garbage collection process has started to take much more time than it usually takes. Now as I mentioned earlier when garbage collection is being run all page requests that come in during that period are queued up. Does this explain why possibly page requests are getting queued up, apart from this it could also be the case that you are waiting for a long running database process to complete.      Lets explore the heap a bit more… What is really a case of crisis is when the objects are living long enough to make it to Gen-2 and then dying, this is definitely a high cost operation. But sometimes you need objects in memory, for example when you cache data you hold on to the objects because you need to use them right across the user session, which is acceptable. But if you wanted to see what extreme caching can do to your server then write a simple application that chucks in a lot of data in cache, run a load test over it for about 10-15 minutes, forcing a lot of data in memory causing the heap to run out of memory. If you get to such a state where you start running out of memory the IIS as a mode of recovery restarts the worker process. It is great way to free up all your memory in the heap but this would clear the cache. The problem with this is if the customer had 10 items in their shopping basket and that data was stored in the application cache, the user basket will now be empty forcing them either to get frustrated and go to a competitor website or if the customer is really patient, give it another try! How can you address this, well two ways of addressing this; 1. Workaround – A x86 bit processor only allows a maximum of 4GB of RAM, this means the machine effectively has around 3.4 GB of RAM available, the OS needs about 1.5 GB of RAM to run efficiently, the IIS and .net framework also need their share of memory, leaving you a heap of around 800 MB to play with. Because Team builds by default build your application in ‘Compile as any mode’ it means the application is build such that it will run in x86 bit mode if run on a x86 bit processor and run in a x64 bit mode if run on a x64 but processor. The problem with this is not all applications are really x64 bit compatible specially if you are using com objects or external libraries. So, as a quick win if you compiled your application in x86 bit mode by changing the compile as any selection to compile as x86 in the team build, you will be able to run your application on a x64 bit machine in x86 bit mode (WOW – By running Windows on Windows) and what that means is, you could use 8GB+ worth of RAM, if you take away everything else your application will roughly get a heap size of at least 4 GB to play with, which is immense. If you need a heap size of more than 4 GB you have either build a software for NASA or there is something fundamentally wrong in your application. 2. Solution – Now that you have put a workaround in place the IIS will not restart the worker process that regularly, which means you can take a breather and start working to get to the root cause of this memory leak. But this begs a question “How do I Identify possible memory leaks in my application?” Well i won’t say that there is one single tool that can tell you where the memory leak is, but trust me, ‘Performance Profiling’ is a great start point, it definitely gets you started in the right direction, let’s have a look at how. Performance Wizard - Start the Performance Wizard and select Instrumentation, this lets you measure function call counts and timings. Before running the performance session right click the performance session settings and chose properties from the context menu to bring up the Performance session properties page and as shown in the screen shot below, check the check boxes in the group ‘.NET memory profiling collection’ namely ‘Collect .NET object allocation information’ and ‘Also collect the .NET Object lifetime information’.    Now if you fire off the profiling session on your pages you will notice that the results allows you to view ‘Object Lifetime’ which shows you the number of objects that made it to Gen-0, Gen-1, Gen-2, Large heap, etc. Another great feature about the profile is that if your application has > 5% cases where objects die right after making to the Gen-2 storage a threshold alert is generated to alert you. Since you have the option to also view the most expensive methods and by capturing the IntelliTrace data you can drill in to narrow down to the line of code that is the root cause of the problem. Well now that we have seen how crucial memory management is and how easy Visual Studio Ultimate 2010 makes it for us to identify and reproduce the problem with the best of breed tools in the product. Caching One of the main ways to improve performance is Caching. Which basically means you tell the web server that instead of going to the database for each request you keep the data in the webserver and when the user asks for it you serve it from the webserver itself. BUT that can have consequences! Let’s look at some code, trust me caching code is not very intuitive, I define a cache key for almost all searches made through the common search page and cache the results. The approach works fine, first time i get the data from the database and second time data is served from the cache, significant performance improvement, EXCEPT when two users try to do the same operation and run into each other. But it is easy to handle this by adding the lock as you can see in the snippet below. So, as long as a user comes in and finds that the cache is empty, the user locks and starts to get the cache no more concurrency issues. But lets say you are processing 10 requests per second, by the time i have locked the operation to get the results from the database, 9 other users came in and found that the cache key is null so after i have come out and populated the cache they will still go in to get the results again. The application will still be faster because the next set of 10 users and so on would continue to get data from the cache. BUT if we added another null check after locking to build the cache and before actual call to the db then the 9 users who follow me would not make the extra trip to the database at all and that would really increase the performance, but didn’t i say that the code won’t be very intuitive, may be you should leave a comment you don’t want another developer to come in and think what a fresher why is he checking for the cache key null twice !!! The downside of caching is, you are storing the data outside of the database and the data could be wrong because the updates applied to the database would make the data cached at the web server out of sync. So, how do you invalidate the cache? Well if you only had one way of updating the data lets say only one entry point to the data update you can write some logic to say that every time new data is entered set the cache object to null. But this approach will not work as soon as you have several ways of feeding data to the system or your system is scaled out across a farm of web servers. The perfect solution to this is Micro Caching which means you cache the query for a set time duration and invalidate the cache after that set duration. The advantage is every time the user queries for that data with in the time span for which you have cached the results there are no calls made to the database and the data is served right from the server which makes the response immensely quick. Now figuring out the appropriate time span for which you micro cache the query results really depends on the application. Lets say your website gets 10 requests per second, if you retain the cache results for even 1 minute you will have immense performance gains. You would reduce 90% hits to the database for searching. Ever wondered why when you go to e-bookers.com or xpedia.com or yatra.com to book a flight and you click on the book button because the fare seems too exciting and you get an error message telling you that the fare is not valid any more. Yes, exactly => That is a cache failure! These travel sites or price compare engines are not going to hit the database every time you hit the compare button instead the results will be served from the cache, because the query results are micro cached, its a perfect trade-off, by micro caching the results the site gains 100% performance benefits but every once in a while annoys a customer because the fare has expired. But the trade off works in the favour of these sites as they are still able to process up to 30+ page requests per second which means cater to the site traffic by may be losing 1 customer every once in a while to a competitor who is also using a similar caching technique what are the odds that the user will not come back to their site sooner or later? Recap   Resources Below are some Key resource you might like to review. I would highly recommend the documentation, walkthroughs and videos available on MSDN. You can always make use of Fiddler to debug Web Performance Tests. Some community test extensions and plug ins available on Codeplex might also be of interest to you. The Road Ahead Thank you for taking the time out and reading this blog post, you may also want to read Part I and Part II if you haven’t so far. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. Next ‘Load Testing in the cloud’, I’ll be working on exploring the possibilities of running Test controller/Agents in the Cloud. See you on the other side! Thank You!   Share this post : CodeProject

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• Unable to connect to Samba printer

  - by user127236

  I have a headless Ubuntu 12.04 server for files and printers. It shares files via Samba just fine. However, the HP PSC-750xi connected to the server via USB is not accessible from my Ubuntu 12.04 laptop. I can browse for it in the Printing control panel, but any attempt to authenticate my ID to the printer with my user credentials results in the error "This print share is not accessible". I have included the Samba smb.conf file below. Any help appreciated. Thanks... JGB # # Sample configuration file for the Samba suite for Debian GNU/Linux. # # # This is the main Samba configuration file. You should read the # smb.conf(5) manual page in order to understand the options listed # here. Samba has a huge number of configurable options most of which # are not shown in this example # # Some options that are often worth tuning have been included as # commented-out examples in this file. # - When such options are commented with ";", the proposed setting # differs from the default Samba behaviour # - When commented with "#", the proposed setting is the default # behaviour of Samba but the option is considered important # enough to be mentioned here # # NOTE: Whenever you modify this file you should run the command # "testparm" to check that you have not made any basic syntactic # errors. # A well-established practice is to name the original file # "smb.conf.master" and create the "real" config file with # testparm -s smb.conf.master >smb.conf # This minimizes the size of the really used smb.conf file # which, according to the Samba Team, impacts performance # However, use this with caution if your smb.conf file contains nested # "include" statements. See Debian bug #483187 for a case # where using a master file is not a good idea. # #======================= Global Settings ======================= [global] log file = /var/log/samba/log.%m passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* . obey pam restrictions = yes map to guest = bad user encrypt passwords = true passwd program = /usr/bin/passwd %u passdb backend = tdbsam dns proxy = no writeable = yes server string = %h server (Samba, Ubuntu) unix password sync = yes workgroup = WORKGROUP syslog = 0 panic action = /usr/share/samba/panic-action %d usershare allow guests = yes max log size = 1000 pam password change = yes ## Browsing/Identification ### # Change this to the workgroup/NT-domain name your Samba server will part of # server string is the equivalent of the NT Description field # Windows Internet Name Serving Support Section: # WINS Support - Tells the NMBD component of Samba to enable its WINS Server # wins support = no # WINS Server - Tells the NMBD components of Samba to be a WINS Client # Note: Samba can be either a WINS Server, or a WINS Client, but NOT both ; wins server = w.x.y.z # This will prevent nmbd to search for NetBIOS names through DNS. # What naming service and in what order should we use to resolve host names # to IP addresses ; name resolve order = lmhosts host wins bcast #### Networking #### # The specific set of interfaces / networks to bind to # This can be either the interface name or an IP address/netmask; # interface names are normally preferred ; interfaces = 127.0.0.0/8 eth0 # Only bind to the named interfaces and/or networks; you must use the # 'interfaces' option above to use this. # It is recommended that you enable this feature if your Samba machine is # not protected by a firewall or is a firewall itself. However, this # option cannot handle dynamic or non-broadcast interfaces correctly. ; bind interfaces only = yes #### Debugging/Accounting #### # This tells Samba to use a separate log file for each machine # that connects # Cap the size of the individual log files (in KiB). # If you want Samba to only log through syslog then set the following # parameter to 'yes'. # syslog only = no # We want Samba to log a minimum amount of information to syslog. Everything # should go to /var/log/samba/log.{smbd,nmbd} instead. If you want to log # through syslog you should set the following parameter to something higher. # Do something sensible when Samba crashes: mail the admin a backtrace ####### Authentication ####### # "security = user" is always a good idea. This will require a Unix account # in this server for every user accessing the server. See # /usr/share/doc/samba-doc/htmldocs/Samba3-HOWTO/ServerType.html # in the samba-doc package for details. # security = user # You may wish to use password encryption. See the section on # 'encrypt passwords' in the smb.conf(5) manpage before enabling. # If you are using encrypted passwords, Samba will need to know what # password database type you are using. # This boolean parameter controls whether Samba attempts to sync the Unix # password with the SMB password when the encrypted SMB password in the # passdb is changed. # For Unix password sync to work on a Debian GNU/Linux system, the following # parameters must be set (thanks to Ian Kahan <<[email protected]> for # sending the correct chat script for the passwd program in Debian Sarge). # This boolean controls whether PAM will be used for password changes # when requested by an SMB client instead of the program listed in # 'passwd program'. The default is 'no'. # This option controls how unsuccessful authentication attempts are mapped # to anonymous connections ########## Domains ########### # Is this machine able to authenticate users. Both PDC and BDC # must have this setting enabled. If you are the BDC you must # change the 'domain master' setting to no # ; domain logons = yes # # The following setting only takes effect if 'domain logons' is set # It specifies the location of the user's profile directory # from the client point of view) # The following required a [profiles] share to be setup on the # samba server (see below) ; logon path = \\%N\profiles\%U # Another common choice is storing the profile in the user's home directory # (this is Samba's default) # logon path = \\%N\%U\profile # The following setting only takes effect if 'domain logons' is set # It specifies the location of a user's home directory (from the client # point of view) ; logon drive = H: # logon home = \\%N\%U # The following setting only takes effect if 'domain logons' is set # It specifies the script to run during logon. The script must be stored # in the [netlogon] share # NOTE: Must be store in 'DOS' file format convention ; logon script = logon.cmd # This allows Unix users to be created on the domain controller via the SAMR # RPC pipe. The example command creates a user account with a disabled Unix # password; please adapt to your needs ; add user script = /usr/sbin/adduser --quiet --disabled-password --gecos "" %u # This allows machine accounts to be created on the domain controller via the # SAMR RPC pipe. # The following assumes a "machines" group exists on the system ; add machine script = /usr/sbin/useradd -g machines -c "%u machine account" -d /var/lib/samba -s /bin/false %u # This allows Unix groups to be created on the domain controller via the SAMR # RPC pipe. ; add group script = /usr/sbin/addgroup --force-badname %g ########## Printing ########## # If you want to automatically load your printer list rather # than setting them up individually then you'll need this # load printers = yes # lpr(ng) printing. You may wish to override the location of the # printcap file ; printing = bsd ; printcap name = /etc/printcap # CUPS printing. See also the cupsaddsmb(8) manpage in the # cupsys-client package. ; printing = cups ; printcap name = cups ############ Misc ############ # Using the following line enables you to customise your configuration # on a per machine basis. The %m gets replaced with the netbios name # of the machine that is connecting ; include = /home/samba/etc/smb.conf.%m # Most people will find that this option gives better performance. # See smb.conf(5) and /usr/share/doc/samba-doc/htmldocs/Samba3-HOWTO/speed.html # for details # You may want to add the following on a Linux system: # SO_RCVBUF=8192 SO_SNDBUF=8192 # socket options = TCP_NODELAY # The following parameter is useful only if you have the linpopup package # installed. The samba maintainer and the linpopup maintainer are # working to ease installation and configuration of linpopup and samba. ; message command = /bin/sh -c '/usr/bin/linpopup "%f" "%m" %s; rm %s' & # Domain Master specifies Samba to be the Domain Master Browser. If this # machine will be configured as a BDC (a secondary logon server), you # must set this to 'no'; otherwise, the default behavior is recommended. # domain master = auto # Some defaults for winbind (make sure you're not using the ranges # for something else.) ; idmap uid = 10000-20000 ; idmap gid = 10000-20000 ; template shell = /bin/bash # The following was the default behaviour in sarge, # but samba upstream reverted the default because it might induce # performance issues in large organizations. # See Debian bug #368251 for some of the consequences of *not* # having this setting and smb.conf(5) for details. ; winbind enum groups = yes ; winbind enum users = yes # Setup usershare options to enable non-root users to share folders # with the net usershare command. # Maximum number of usershare. 0 (default) means that usershare is disabled. ; usershare max shares = 100 # Allow users who've been granted usershare privileges to create # public shares, not just authenticated ones #======================= Share Definitions ======================= # Un-comment the following (and tweak the other settings below to suit) # to enable the default home directory shares. This will share each # user's home director as \\server\username ;[homes] ; comment = Home Directories ; browseable = no # By default, the home directories are exported read-only. Change the # next parameter to 'no' if you want to be able to write to them. ; read only = yes # File creation mask is set to 0700 for security reasons. If you want to # create files with group=rw permissions, set next parameter to 0775. ; create mask = 0700 # Directory creation mask is set to 0700 for security reasons. If you want to # create dirs. with group=rw permissions, set next parameter to 0775. ; directory mask = 0700 # By default, \\server\username shares can be connected to by anyone # with access to the samba server. Un-comment the following parameter # to make sure that only "username" can connect to \\server\username # The following parameter makes sure that only "username" can connect # # This might need tweaking when using external authentication schemes ; valid users = %S # Un-comment the following and create the netlogon directory for Domain Logons # (you need to configure Samba to act as a domain controller too.) ;[netlogon] ; comment = Network Logon Service ; path = /home/samba/netlogon ; guest ok = yes ; read only = yes # Un-comment the following and create the profiles directory to store # users profiles (see the "logon path" option above) # (you need to configure Samba to act as a domain controller too.) # The path below should be writable by all users so that their # profile directory may be created the first time they log on ;[profiles] ; comment = Users profiles ; path = /home/samba/profiles ; guest ok = no ; browseable = no ; create mask = 0600 ; directory mask = 0700 [printers] comment = All Printers browseable = no path = /var/spool/samba printable = yes guest ok = no read only = yes create mask = 0700 # Windows clients look for this share name as a source of downloadable # printer drivers [print$] comment = Printer Drivers browseable = yes writeable = no path = /var/lib/samba/printers # Uncomment to allow remote administration of Windows print drivers. # You may need to replace 'lpadmin' with the name of the group your # admin users are members of. # Please note that you also need to set appropriate Unix permissions # to the drivers directory for these users to have write rights in it ; write list = root, @lpadmin # A sample share for sharing your CD-ROM with others. ;[cdrom] ; comment = Samba server's CD-ROM ; read only = yes ; locking = no ; path = /cdrom ; guest ok = yes # The next two parameters show how to auto-mount a CD-ROM when the # cdrom share is accesed. For this to work /etc/fstab must contain # an entry like this: # # /dev/scd0 /cdrom iso9660 defaults,noauto,ro,user 0 0 # # The CD-ROM gets unmounted automatically after the connection to the # # If you don't want to use auto-mounting/unmounting make sure the CD # is mounted on /cdrom # ; preexec = /bin/mount /cdrom ; postexec = /bin/umount /cdrom [mediafiles] path = /media/multimedia/

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• C#/.NET Little Wonders: ConcurrentBag and BlockingCollection

  - by James Michael Hare

  In the first week of concurrent collections, began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  The last post discussed the ConcurrentDictionary<T> .  Finally this week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see C#/.NET Little Wonders: A Redux. Recap As you'll recall from the previous posts, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  With .NET 4.0, a new breed of collections was born in the System.Collections.Concurrent namespace.  Of these, the final concurrent collection we will examine is the ConcurrentBag and a very useful wrapper class called the BlockingCollection. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this informative whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentBag<T> – Thread-safe unordered collection. Unlike the other concurrent collections, the ConcurrentBag<T> has no non-concurrent counterpart in the .NET collections libraries.  Items can be added and removed from a bag just like any other collection, but unlike the other collections, the items are not maintained in any order.  This makes the bag handy for those cases when all you care about is that the data be consumed eventually, without regard for order of consumption or even fairness – that is, it’s possible new items could be consumed before older items given the right circumstances for a period of time. So why would you ever want a container that can be unfair?  Well, to look at it another way, you can use a ConcurrentQueue and get the fairness, but it comes at a cost in that the ordering rules and synchronization required to maintain that ordering can affect scalability a bit.  Thus sometimes the bag is great when you want the fastest way to get the next item to process, and don’t care what item it is or how long its been waiting. The way that the ConcurrentBag works is to take advantage of the new ThreadLocal<T> type (new in System.Threading for .NET 4.0) so that each thread using the bag has a list local to just that thread.  This means that adding or removing to a thread-local list requires very low synchronization.  The problem comes in where a thread goes to consume an item but it’s local list is empty.  In this case the bag performs “work-stealing” where it will rob an item from another thread that has items in its list.  This requires a higher level of synchronization which adds a bit of overhead to the take operation. So, as you can imagine, this makes the ConcurrentBag good for situations where each thread both produces and consumes items from the bag, but it would be less-than-idea in situations where some threads are dedicated producers and the other threads are dedicated consumers because the work-stealing synchronization would outweigh the thread-local optimization for a thread taking its own items. Like the other concurrent collections, there are some curiosities to keep in mind: IsEmpty(), Count, ToArray(), and GetEnumerator() lock collection Each of these needs to take a snapshot of whole bag to determine if empty, thus they tend to be more expensive and cause Add() and Take() operations to block. ToArray() and GetEnumerator() are static snapshots Because it is based on a snapshot, will not show subsequent updates after snapshot. Add() is lightweight Since adding to the thread-local list, there is very little overhead on Add. TryTake() is lightweight if items in thread-local list As long as items are in the thread-local list, TryTake() is very lightweight, much more so than ConcurrentStack() and ConcurrentQueue(), however if the local thread list is empty, it must steal work from another thread, which is more expensive. Remember, a bag is not ideal for all situations, it is mainly ideal for situations where a process consumes an item and either decomposes it into more items to be processed, or handles the item partially and places it back to be processed again until some point when it will complete.  The main point is that the bag works best when each thread both takes and adds items. For example, we could create a totally contrived example where perhaps we want to see the largest power of a number before it crosses a certain threshold.  Yes, obviously we could easily do this with a log function, but bare with me while I use this contrived example for simplicity. So let’s say we have a work function that will take a Tuple out of a bag, this Tuple will contain two ints.  The first int is the original number, and the second int is the last multiple of that number.  So we could load our bag with the initial values (let’s say we want to know the last multiple of each of 2, 3, 5, and 7 under 100. 1: var bag = new ConcurrentBag<Tuple<int, int>> 2: { 3: Tuple.Create(2, 1), 4: Tuple.Create(3, 1), 5: Tuple.Create(5, 1), 6: Tuple.Create(7, 1) 7: }; Then we can create a method that given the bag, will take out an item, apply the multiplier again, 1: public static void FindHighestPowerUnder(ConcurrentBag<Tuple<int,int>> bag, int threshold) 2: { 3: Tuple<int,int> pair; 4:  5: // while there are items to take, this will prefer local first, then steal if no local 6: while (bag.TryTake(out pair)) 7: { 8: // look at next power 9: var result = Math.Pow(pair.Item1, pair.Item2 + 1); 10:  11: if (result < threshold) 12: { 13: // if smaller than threshold bump power by 1 14: bag.Add(Tuple.Create(pair.Item1, pair.Item2 + 1)); 15: } 16: else 17: { 18: // otherwise, we're done 19: Console.WriteLine("Highest power of {0} under {3} is {0}^{1} = {2}.", 20: pair.Item1, pair.Item2, Math.Pow(pair.Item1, pair.Item2), threshold); 21: } 22: } 23: } Now that we have this, we can load up this method as an Action into our Tasks and run it: 1: // create array of tasks, start all, wait for all 2: var tasks = new[] 3: { 4: new Task(() => FindHighestPowerUnder(bag, 100)), 5: new Task(() => FindHighestPowerUnder(bag, 100)), 6: }; 7:  8: Array.ForEach(tasks, t => t.Start()); 9:  10: Task.WaitAll(tasks); Totally contrived, I know, but keep in mind the main point!  When you have a thread or task that operates on an item, and then puts it back for further consumption – or decomposes an item into further sub-items to be processed – you should consider a ConcurrentBag as the thread-local lists will allow for quick processing.  However, if you need ordering or if your processes are dedicated producers or consumers, this collection is not ideal.  As with anything, you should performance test as your mileage will vary depending on your situation! BlockingCollection<T> – A producers & consumers pattern collection The BlockingCollection<T> can be treated like a collection in its own right, but in reality it adds a producers and consumers paradigm to any collection that implements the interface IProducerConsumerCollection<T>.  If you don’t specify one at the time of construction, it will use a ConcurrentQueue<T> as its underlying store. If you don’t want to use the ConcurrentQueue, the ConcurrentStack and ConcurrentBag also implement the interface (though ConcurrentDictionary does not).  In addition, you are of course free to create your own implementation of the interface. So, for those who don’t remember the producers and consumers classical computer-science problem, the gist of it is that you have one (or more) processes that are creating items (producers) and one (or more) processes that are consuming these items (consumers).  Now, the crux of the problem is that there is a bin (queue) where the produced items are placed, and typically that bin has a limited size.  Thus if a producer creates an item, but there is no space to store it, it must wait until an item is consumed.  Also if a consumer goes to consume an item and none exists, it must wait until an item is produced. The BlockingCollection makes it trivial to implement any standard producers/consumers process set by providing that “bin” where the items can be produced into and consumed from with the appropriate blocking operations.  In addition, you can specify whether the bin should have a limited size or can be (theoretically) unbounded, and you can specify timeouts on the blocking operations. As far as your choice of “bin”, for the most part the ConcurrentQueue is the right choice because it is fairly light and maximizes fairness by ordering items so that they are consumed in the same order they are produced.  You can use the concurrent bag or stack, of course, but your ordering would be random-ish in the case of the former and LIFO in the case of the latter. So let’s look at some of the methods of note in BlockingCollection: BoundedCapacity returns capacity of the “bin” If the bin is unbounded, the capacity is int.MaxValue. Count returns an internally-kept count of items This makes it O(1), but if you modify underlying collection directly (not recommended) it is unreliable. CompleteAdding() is used to cut off further adds. This sets IsAddingCompleted and begins to wind down consumers once empty. IsAddingCompleted is true when producers are “done”. Once you are done producing, should complete the add process to alert consumers. IsCompleted is true when producers are “done” and “bin” is empty. Once you mark the producers done, and all items removed, this will be true. Add() is a blocking add to collection. If bin is full, will wait till space frees up Take() is a blocking remove from collection. If bin is empty, will wait until item is produced or adding is completed. GetConsumingEnumerable() is used to iterate and consume items. Unlike the standard enumerator, this one consumes the items instead of iteration. TryAdd() attempts add but does not block completely If adding would block, returns false instead, can specify TimeSpan to wait before stopping. TryTake() attempts to take but does not block completely Like TryAdd(), if taking would block, returns false instead, can specify TimeSpan to wait. Note the use of CompleteAdding() to signal the BlockingCollection that nothing else should be added.  This means that any attempts to TryAdd() or Add() after marked completed will throw an InvalidOperationException.  In addition, once adding is complete you can still continue to TryTake() and Take() until the bin is empty, and then Take() will throw the InvalidOperationException and TryTake() will return false. So let’s create a simple program to try this out.  Let’s say that you have one process that will be producing items, but a slower consumer process that handles them.  This gives us a chance to peek inside what happens when the bin is bounded (by default, the bin is NOT bounded). 1: var bin = new BlockingCollection<int>(5); Now, we create a method to produce items: 1: public static void ProduceItems(BlockingCollection<int> bin, int numToProduce) 2: { 3: for (int i = 0; i < numToProduce; i++) 4: { 5: // try for 10 ms to add an item 6: while (!bin.TryAdd(i, TimeSpan.FromMilliseconds(10))) 7: { 8: Console.WriteLine("Bin is full, retrying..."); 9: } 10: } 11:  12: // once done producing, call CompleteAdding() 13: Console.WriteLine("Adding is completed."); 14: bin.CompleteAdding(); 15: } And one to consume them: 1: public static void ConsumeItems(BlockingCollection<int> bin) 2: { 3: // This will only be true if CompleteAdding() was called AND the bin is empty. 4: while (!bin.IsCompleted) 5: { 6: int item; 7:  8: if (!bin.TryTake(out item, TimeSpan.FromMilliseconds(10))) 9: { 10: Console.WriteLine("Bin is empty, retrying..."); 11: } 12: else 13: { 14: Console.WriteLine("Consuming item {0}.", item); 15: Thread.Sleep(TimeSpan.FromMilliseconds(20)); 16: } 17: } 18: } Then we can fire them off: 1: // create one producer and two consumers 2: var tasks = new[] 3: { 4: new Task(() => ProduceItems(bin, 20)), 5: new Task(() => ConsumeItems(bin)), 6: new Task(() => ConsumeItems(bin)), 7: }; 8:  9: Array.ForEach(tasks, t => t.Start()); 10:  11: Task.WaitAll(tasks); Notice that the producer is faster than the consumer, thus it should be hitting a full bin often and displaying the message after it times out on TryAdd(). 1: Consuming item 0. 2: Consuming item 1. 3: Bin is full, retrying... 4: Bin is full, retrying... 5: Consuming item 3. 6: Consuming item 2. 7: Bin is full, retrying... 8: Consuming item 4. 9: Consuming item 5. 10: Bin is full, retrying... 11: Consuming item 6. 12: Consuming item 7. 13: Bin is full, retrying... 14: Consuming item 8. 15: Consuming item 9. 16: Bin is full, retrying... 17: Consuming item 10. 18: Consuming item 11. 19: Bin is full, retrying... 20: Consuming item 12. 21: Consuming item 13. 22: Bin is full, retrying... 23: Bin is full, retrying... 24: Consuming item 14. 25: Adding is completed. 26: Consuming item 15. 27: Consuming item 16. 28: Consuming item 17. 29: Consuming item 19. 30: Consuming item 18. Also notice that once CompleteAdding() is called and the bin is empty, the IsCompleted property returns true, and the consumers will exit. Summary The ConcurrentBag is an interesting collection that can be used to optimize concurrency scenarios where tasks or threads both produce and consume items.  In this way, it will choose to consume its own work if available, and then steal if not.  However, in situations where you want fair consumption or ordering, or in situations where the producers and consumers are distinct processes, the bag is not optimal. The BlockingCollection is a great wrapper around all of the concurrent queue, stack, and bag that allows you to add producer and consumer semantics easily including waiting when the bin is full or empty. That’s the end of my dive into the concurrent collections.  I’d also strongly recommend, once again, you read this excellent Microsoft white paper that goes into much greater detail on the efficiencies you can gain using these collections judiciously (here). Tweet Technorati Tags: C#,.NET,Concurrent Collections,Little Wonders

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• What's up with OCFS2?

  - by wcoekaer

  On Linux there are many filesystem choices and even from Oracle we provide a number of filesystems, all with their own advantages and use cases. Customers often confuse ACFS with OCFS or OCFS2 which then causes assumptions to be made such as one replacing the other etc... I thought it would be good to write up a summary of how OCFS2 got to where it is, what we're up to still, how it is different from other options and how this really is a cool native Linux cluster filesystem that we worked on for many years and is still widely used. Work on a cluster filesystem at Oracle started many years ago, in the early 2000's when the Oracle Database Cluster development team wrote a cluster filesystem for Windows that was primarily focused on providing an alternative to raw disk devices and help customers with the deployment of Oracle Real Application Cluster (RAC). Oracle RAC is a cluster technology that lets us make a cluster of Oracle Database servers look like one big database. The RDBMS runs on many nodes and they all work on the same data. It's a Shared Disk database design. There are many advantages doing this but I will not go into detail as that is not the purpose of my write up. Suffice it to say that Oracle RAC expects all the database data to be visible in a consistent, coherent way, across all the nodes in the cluster. To do that, there were/are a few options : 1) use raw disk devices that are shared, through SCSI, FC, or iSCSI 2) use a network filesystem (NFS) 3) use a cluster filesystem(CFS) which basically gives you a filesystem that's coherent across all nodes using shared disks. It is sort of (but not quite) combining option 1 and 2 except that you don't do network access to the files, the files are effectively locally visible as if it was a local filesystem. So OCFS (Oracle Cluster FileSystem) on Windows was born. Since Linux was becoming a very important and popular platform, we decided that we would also make this available on Linux and thus the porting of OCFS/Windows started. The first version of OCFS was really primarily focused on replacing the use of Raw devices with a simple filesystem that lets you create files and provide direct IO to these files to get basically native raw disk performance. The filesystem was not designed to be fully POSIX compliant and it did not have any where near good/decent performance for regular file create/delete/access operations. Cache coherency was easy since it was basically always direct IO down to the disk device and this ensured that any time one issues a write() command it would go directly down to the disk, and not return until the write() was completed. Same for read() any sort of read from a datafile would be a read() operation that went all the way to disk and return. We did not cache any data when it came down to Oracle data files. So while OCFS worked well for that, since it did not have much of a normal filesystem feel, it was not something that could be submitted to the kernel mail list for inclusion into Linux as another native linux filesystem (setting aside the Windows porting code ...) it did its job well, it was very easy to configure, node membership was simple, locking was disk based (so very slow but it existed), you could create regular files and do regular filesystem operations to a certain extend but anything that was not database data file related was just not very useful in general. Logfiles ok, standard filesystem use, not so much. Up to this point, all the work was done, at Oracle, by Oracle developers. Once OCFS (1) was out for a while and there was a lot of use in the database RAC world, many customers wanted to do more and were asking for features that you'd expect in a normal native filesystem, a real "general purposes cluster filesystem". So the team sat down and basically started from scratch to implement what's now known as OCFS2 (Oracle Cluster FileSystem release 2). Some basic criteria were : Design it with a real Distributed Lock Manager and use the network for lock negotiation instead of the disk Make it a Linux native filesystem instead of a native shim layer and a portable core Support standard Posix compliancy and be fully cache coherent with all operations Support all the filesystem features Linux offers (ACL, extended Attributes, quotas, sparse files,...) Be modern, support large files, 32/64bit, journaling, data ordered journaling, endian neutral, we can mount on both endian /cross architecture,.. Needless to say, this was a huge development effort that took many years to complete. A few big milestones happened along the way... OCFS2 was development in the open, we did not have a private tree that we worked on without external code review from the Linux Filesystem maintainers, great folks like Christopher Hellwig reviewed the code regularly to make sure we were not doing anything out of line, we submitted the code for review on lkml a number of times to see if we were getting close for it to be included into the mainline kernel. Using this development model is standard practice for anyone that wants to write code that goes into the kernel and having any chance of doing so without a complete rewrite or.. shall I say flamefest when submitted. It saved us a tremendous amount of time by not having to re-fit code for it to be in a Linus acceptable state. Some other filesystems that were trying to get into the kernel that didn't follow an open development model had a lot harder time and a lot harsher criticism. March 2006, when Linus released 2.6.16, OCFS2 officially became part of the mainline kernel, it was accepted a little earlier in the release candidates but in 2.6.16. OCFS2 became officially part of the mainline Linux kernel tree as one of the many filesystems. It was the first cluster filesystem to make it into the kernel tree. Our hope was that it would then end up getting picked up by the distribution vendors to make it easy for everyone to have access to a CFS. Today the source code for OCFS2 is approximately 85000 lines of code. We made OCFS2 production with full support for customers that ran Oracle database on Linux, no extra or separate support contract needed. OCFS2 1.0.0 started being built for RHEL4 for x86, x86-64, ppc, s390x and ia64. For RHEL5 starting with OCFS2 1.2. SuSE was very interested in high availability and clustering and decided to build and include OCFS2 with SLES9 for their customers and was, next to Oracle, the main contributor to the filesystem for both new features and bug fixes. Source code was always available even prior to inclusion into mainline and as of 2.6.16, source code was just part of a Linux kernel download from kernel.org, which it still is, today. So the latest OCFS2 code is always the upstream mainline Linux kernel. OCFS2 is the cluster filesystem used in Oracle VM 2 and Oracle VM 3 as the virtual disk repository filesystem. Since the filesystem is in the Linux kernel it's released under the GPL v2 The release model has always been that new feature development happened in the mainline kernel and we then built consistent, well tested, snapshots that had versions, 1.2, 1.4, 1.6, 1.8. But these releases were effectively just snapshots in time that were tested for stability and release quality. OCFS2 is very easy to use, there's a simple text file that contains the node information (hostname, node number, cluster name) and a file that contains the cluster heartbeat timeouts. It is very small, and very efficient. As Sunil Mushran wrote in the manual : OCFS2 is an efficient, easily configured, quickly installed, fully integrated and compatible, feature-rich, architecture and endian neutral, cache coherent, ordered data journaling, POSIX-compliant, shared disk cluster file system. Here is a list of some of the important features that are included : Variable Block and Cluster sizes Supports block sizes ranging from 512 bytes to 4 KB and cluster sizes ranging from 4 KB to 1 MB (increments in power of 2). Extent-based Allocations Tracks the allocated space in ranges of clusters making it especially efficient for storing very large files. Optimized Allocations Supports sparse files, inline-data, unwritten extents, hole punching and allocation reservation for higher performance and efficient storage. File Cloning/snapshots REFLINK is a feature which introduces copy-on-write clones of files in a cluster coherent way. Indexed Directories Allows efficient access to millions of objects in a directory. Metadata Checksums Detects silent corruption in inodes and directories. Extended Attributes Supports attaching an unlimited number of name:value pairs to the file system objects like regular files, directories, symbolic links, etc. Advanced Security Supports POSIX ACLs and SELinux in addition to the traditional file access permission model. Quotas Supports user and group quotas. Journaling Supports both ordered and writeback data journaling modes to provide file system consistency in the event of power failure or system crash. Endian and Architecture neutral Supports a cluster of nodes with mixed architectures. Allows concurrent mounts on nodes running 32-bit and 64-bit, little-endian (x86, x86_64, ia64) and big-endian (ppc64) architectures. In-built Cluster-stack with DLM Includes an easy to configure, in-kernel cluster-stack with a distributed lock manager. Buffered, Direct, Asynchronous, Splice and Memory Mapped I/Os Supports all modes of I/Os for maximum flexibility and performance. Comprehensive Tools Support Provides a familiar EXT3-style tool-set that uses similar parameters for ease-of-use. The filesystem was distributed for Linux distributions in separate RPM form and this had to be built for every single kernel errata release or every updated kernel provided by the vendor. We provided builds from Oracle for Oracle Linux and all kernels released by Oracle and for Red Hat Enterprise Linux. SuSE provided the modules directly for every kernel they shipped. With the introduction of the Unbreakable Enterprise Kernel for Oracle Linux and our interest in reducing the overhead of building filesystem modules for every minor release, we decide to make OCFS2 available as part of UEK. There was no more need for separate kernel modules, everything was built-in and a kernel upgrade automatically updated the filesystem, as it should. UEK allowed us to not having to backport new upstream filesystem code into an older kernel version, backporting features into older versions introduces risk and requires extra testing because the code is basically partially rewritten. The UEK model works really well for continuing to provide OCFS2 without that extra overhead. Because the RHEL kernel did not contain OCFS2 as a kernel module (it is in the source tree but it is not built by the vendor in kernel module form) we stopped adding the extra packages to Oracle Linux and its RHEL compatible kernel and for RHEL. Oracle Linux customers/users obviously get OCFS2 included as part of the Unbreakable Enterprise Kernel, SuSE customers get it by SuSE distributed with SLES and Red Hat can decide to distribute OCFS2 to their customers if they chose to as it's just a matter of compiling the module and making it available. OCFS2 today, in the mainline kernel is pretty much feature complete in terms of integration with every filesystem feature Linux offers and it is still actively maintained with Joel Becker being the primary maintainer. Since we use OCFS2 as part of Oracle VM, we continue to look at interesting new functionality to add, REFLINK was a good example, and as such we continue to enhance the filesystem where it makes sense. Bugfixes and any sort of code that goes into the mainline Linux kernel that affects filesystems, automatically also modifies OCFS2 so it's in kernel, actively maintained but not a lot of new development happening at this time. We continue to fully support OCFS2 as part of Oracle Linux and the Unbreakable Enterprise Kernel and other vendors make their own decisions on support as it's really a Linux cluster filesystem now more than something that we provide to customers. It really just is part of Linux like EXT3 or BTRFS etc, the OS distribution vendors decide. Do not confuse OCFS2 with ACFS (ASM cluster Filesystem) also known as Oracle Cloud Filesystem. ACFS is a filesystem that's provided by Oracle on various OS platforms and really integrates into Oracle ASM (Automatic Storage Management). It's a very powerful Cluster Filesystem but it's not distributed as part of the Operating System, it's distributed with the Oracle Database product and installs with and lives inside Oracle ASM. ACFS obviously is fully supported on Linux (Oracle Linux, Red Hat Enterprise Linux) but OCFS2 independently as a native Linux filesystem is also, and continues to also be supported. ACFS is very much tied into the Oracle RDBMS, OCFS2 is just a standard native Linux filesystem with no ties into Oracle products. Customers running the Oracle database and ASM really should consider using ACFS as it also provides storage/clustered volume management. Customers wanting to use a simple, easy to use generic Linux cluster filesystem should consider using OCFS2. To learn more about OCFS2 in detail, you can find good documentation on http://oss.oracle.com/projects/ocfs2 in the Documentation area, or get the latest mainline kernel from http://kernel.org and read the source. One final, unrelated note - since I am not always able to publicly answer or respond to comments, I do not want to selectively publish comments from readers. Sometimes I forget to publish comments, sometime I publish them and sometimes I would publish them but if for some reason I cannot publicly comment on them, it becomes a very one-sided stream. So for now I am going to not publish comments from anyone, to be fair to all sides. You are always welcome to email me and I will do my best to respond to technical questions, questions about strategy or direction are sometimes not possible to answer for obvious reasons.

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• Plan Caching and Query Memory Part II (Hash Match) – When not to use stored procedure - Most common performance mistake SQL Server developers make.

  - by sqlworkshops

  SQL Server estimates Memory requirement at compile time, when stored procedure or other plan caching mechanisms like sp_executesql or prepared statement are used, the memory requirement is estimated based on first set of execution parameters. This is a common reason for spill over tempdb and hence poor performance. Common memory allocating queries are that perform Sort and do Hash Match operations like Hash Join or Hash Aggregation or Hash Union. This article covers Hash Match operations with examples. It is recommended to read Plan Caching and Query Memory Part I before this article which covers an introduction and Query memory for Sort. In most cases it is cheaper to pay for the compilation cost of dynamic queries than huge cost for spill over tempdb, unless memory requirement for a query does not change significantly based on predicates.   This article covers underestimation / overestimation of memory for Hash Match operation. Plan Caching and Query Memory Part I covers underestimation / overestimation for Sort. It is important to note that underestimation of memory for Sort and Hash Match operations lead to spill over tempdb and hence negatively impact performance. Overestimation of memory affects the memory needs of other concurrently executing queries. In addition, it is important to note, with Hash Match operations, overestimation of memory can actually lead to poor performance.   To read additional articles I wrote click here.   The best way to learn is to practice. To create the below tables and reproduce the behavior, join the mailing list by using this link: www.sqlworkshops.com/ml and I will send you the table creation script. Most of these concepts are also covered in our webcasts: www.sqlworkshops.com/webcasts  Let’s create a Customer’s State table that has 99% of customers in NY and the rest 1% in WA.Customers table used in Part I of this article is also used here.To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'. --Example provided by www.sqlworkshops.com drop table CustomersState go create table CustomersState (CustomerID int primary key, Address char(200), State char(2)) go insert into CustomersState (CustomerID, Address) select CustomerID, 'Address' from Customers update CustomersState set State = 'NY' where CustomerID % 100 != 1 update CustomersState set State = 'WA' where CustomerID % 100 = 1 go update statistics CustomersState with fullscan go   Let’s create a stored procedure that joins customers with CustomersState table with a predicate on State. --Example provided by www.sqlworkshops.com create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1) end go  Let’s execute the stored procedure first with parameter value ‘WA’ – which will select 1% of data. set statistics time on go --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' goThe stored procedure took 294 ms to complete.  The stored procedure was granted 6704 KB based on 8000 rows being estimated.  The estimated number of rows, 8000 is similar to actual number of rows 8000 and hence the memory estimation should be ok.  There was no Hash Warning in SQL Profiler. To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'.   Now let’s execute the stored procedure with parameter value ‘NY’ – which will select 99% of data. -Example provided by www.sqlworkshops.com exec CustomersByState 'NY' go  The stored procedure took 2922 ms to complete.   The stored procedure was granted 6704 KB based on 8000 rows being estimated.    The estimated number of rows, 8000 is way different from the actual number of rows 792000 because the estimation is based on the first set of parameter value supplied to the stored procedure which is ‘WA’ in our case. This underestimation will lead to spill over tempdb, resulting in poor performance.   There was Hash Warning (Recursion) in SQL Profiler. To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'.   Let’s recompile the stored procedure and then let’s first execute the stored procedure with parameter value ‘NY’.  In a production instance it is not advisable to use sp_recompile instead one should use DBCC FREEPROCCACHE (plan_handle). This is due to locking issues involved with sp_recompile, refer to our webcasts, www.sqlworkshops.com/webcasts for further details.   exec sp_recompile CustomersByState go --Example provided by www.sqlworkshops.com exec CustomersByState 'NY' go  Now the stored procedure took only 1046 ms instead of 2922 ms.   The stored procedure was granted 146752 KB of memory. The estimated number of rows, 792000 is similar to actual number of rows of 792000. Better performance of this stored procedure execution is due to better estimation of memory and avoiding spill over tempdb.   There was no Hash Warning in SQL Profiler.   Now let’s execute the stored procedure with parameter value ‘WA’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go  The stored procedure took 351 ms to complete, higher than the previous execution time of 294 ms.    This stored procedure was granted more memory (146752 KB) than necessary (6704 KB) based on parameter value ‘NY’ for estimation (792000 rows) instead of parameter value ‘WA’ for estimation (8000 rows). This is because the estimation is based on the first set of parameter value supplied to the stored procedure which is ‘NY’ in this case. This overestimation leads to poor performance of this Hash Match operation, it might also affect the performance of other concurrently executing queries requiring memory and hence overestimation is not recommended.     The estimated number of rows, 792000 is much more than the actual number of rows of 8000.  Intermediate Summary: This issue can be avoided by not caching the plan for memory allocating queries. Other possibility is to use recompile hint or optimize for hint to allocate memory for predefined data range.Let’s recreate the stored procedure with recompile hint. --Example provided by www.sqlworkshops.com drop proc CustomersByState go create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1, recompile) end go  Let’s execute the stored procedure initially with parameter value ‘WA’ and then with parameter value ‘NY’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go exec CustomersByState 'NY' go  The stored procedure took 297 ms and 1102 ms in line with previous optimal execution times.   The stored procedure with parameter value ‘WA’ has good estimation like before.   Estimated number of rows of 8000 is similar to actual number of rows of 8000.   The stored procedure with parameter value ‘NY’ also has good estimation and memory grant like before because the stored procedure was recompiled with current set of parameter values.  Estimated number of rows of 792000 is similar to actual number of rows of 792000.    The compilation time and compilation CPU of 1 ms is not expensive in this case compared to the performance benefit.   There was no Hash Warning in SQL Profiler.   Let’s recreate the stored procedure with optimize for hint of ‘NY’. --Example provided by www.sqlworkshops.com drop proc CustomersByState go create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1, optimize for (@State = 'NY')) end go  Let’s execute the stored procedure initially with parameter value ‘WA’ and then with parameter value ‘NY’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go exec CustomersByState 'NY' go  The stored procedure took 353 ms with parameter value ‘WA’, this is much slower than the optimal execution time of 294 ms we observed previously. This is because of overestimation of memory. The stored procedure with parameter value ‘NY’ has optimal execution time like before.   The stored procedure with parameter value ‘WA’ has overestimation of rows because of optimize for hint value of ‘NY’.   Unlike before, more memory was estimated to this stored procedure based on optimize for hint value ‘NY’.    The stored procedure with parameter value ‘NY’ has good estimation because of optimize for hint value of ‘NY’. Estimated number of rows of 792000 is similar to actual number of rows of 792000.   Optimal amount memory was estimated to this stored procedure based on optimize for hint value ‘NY’.   There was no Hash Warning in SQL Profiler.   This article covers underestimation / overestimation of memory for Hash Match operation. Plan Caching and Query Memory Part I covers underestimation / overestimation for Sort. It is important to note that underestimation of memory for Sort and Hash Match operations lead to spill over tempdb and hence negatively impact performance. Overestimation of memory affects the memory needs of other concurrently executing queries. In addition, it is important to note, with Hash Match operations, overestimation of memory can actually lead to poor performance.   Summary: Cached plan might lead to underestimation or overestimation of memory because the memory is estimated based on first set of execution parameters. It is recommended not to cache the plan if the amount of memory required to execute the stored procedure has a wide range of possibilities. One can mitigate this by using recompile hint, but that will lead to compilation overhead. However, in most cases it might be ok to pay for compilation rather than spilling sort over tempdb which could be very expensive compared to compilation cost. The other possibility is to use optimize for hint, but in case one sorts more data than hinted by optimize for hint, this will still lead to spill. On the other side there is also the possibility of overestimation leading to unnecessary memory issues for other concurrently executing queries. In case of Hash Match operations, this overestimation of memory might lead to poor performance. When the values used in optimize for hint are archived from the database, the estimation will be wrong leading to worst performance, so one has to exercise caution before using optimize for hint, recompile hint is better in this case.   I explain these concepts with detailed examples in my webcasts (www.sqlworkshops.com/webcasts), I recommend you to watch them. The best way to learn is to practice. To create the above tables and reproduce the behavior, join the mailing list at www.sqlworkshops.com/ml and I will send you the relevant SQL Scripts.  Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   Disclaimer and copyright information:This article refers to organizations and products that may be the trademarks or registered trademarks of their various owners. Copyright of this article belongs to R Meyyappan / www.sqlworkshops.com. You may freely use the ideas and concepts discussed in this article with acknowledgement (www.sqlworkshops.com), but you may not claim any of it as your own work. This article is for informational purposes only; you use any of the suggestions given here entirely at your own risk.   R Meyyappan [email protected] LinkedIn: http://at.linkedin.com/in/rmeyyappan

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• Inside the Concurrent Collections: ConcurrentDictionary

  - by Simon Cooper

  Using locks to implement a thread-safe collection is rather like using a sledgehammer - unsubtle, easy to understand, and tends to make any other tool redundant. Unlike the previous two collections I looked at, ConcurrentStack and ConcurrentQueue, ConcurrentDictionary uses locks quite heavily. However, it is careful to wield locks only where necessary to ensure that concurrency is maximised. This will, by necessity, be a higher-level look than my other posts in this series, as there is quite a lot of code and logic in ConcurrentDictionary. Therefore, I do recommend that you have ConcurrentDictionary open in a decompiler to have a look at all the details that I skip over. The problem with locks There's several things to bear in mind when using locks, as encapsulated by the lock keyword in C# and the System.Threading.Monitor class in .NET (if you're unsure as to what lock does in C#, I briefly covered it in my first post in the series): Locks block threads The most obvious problem is that threads waiting on a lock can't do any work at all. No preparatory work, no 'optimistic' work like in ConcurrentQueue and ConcurrentStack, nothing. It sits there, waiting to be unblocked. This is bad if you're trying to maximise concurrency. Locks are slow Whereas most of the methods on the Interlocked class can be compiled down to a single CPU instruction, ensuring atomicity at the hardware level, taking out a lock requires some heavy lifting by the CLR and the operating system. There's quite a bit of work required to take out a lock, block other threads, and wake them up again. If locks are used heavily, this impacts performance. Deadlocks When using locks there's always the possibility of a deadlock - two threads, each holding a lock, each trying to aquire the other's lock. Fortunately, this can be avoided with careful programming and structured lock-taking, as we'll see. So, it's important to minimise where locks are used to maximise the concurrency and performance of the collection. Implementation As you might expect, ConcurrentDictionary is similar in basic implementation to the non-concurrent Dictionary, which I studied in a previous post. I'll be using some concepts introduced there, so I recommend you have a quick read of it. So, if you were implementing a thread-safe dictionary, what would you do? The naive implementation is to simply have a single lock around all methods accessing the dictionary. This would work, but doesn't allow much concurrency. Fortunately, the bucketing used by Dictionary allows a simple but effective improvement to this - one lock per bucket. This allows different threads modifying different buckets to do so in parallel. Any thread making changes to the contents of a bucket takes the lock for that bucket, ensuring those changes are thread-safe. The method that maps each bucket to a lock is the GetBucketAndLockNo method: private void GetBucketAndLockNo( int hashcode, out int bucketNo, out int lockNo, int bucketCount) { // the bucket number is the hashcode (without the initial sign bit) // modulo the number of buckets bucketNo = (hashcode & 0x7fffffff) % bucketCount; // and the lock number is the bucket number modulo the number of locks lockNo = bucketNo % m_locks.Length; } However, this does require some changes to how the buckets are implemented. The 'implicit' linked list within a single backing array used by the non-concurrent Dictionary adds a dependency between separate buckets, as every bucket uses the same backing array. Instead, ConcurrentDictionary uses a strict linked list on each bucket: This ensures that each bucket is entirely separate from all other buckets; adding or removing an item from a bucket is independent to any changes to other buckets. Modifying the dictionary All the operations on the dictionary follow the same basic pattern: void AlterBucket(TKey key, ...) { int bucketNo, lockNo; 1: GetBucketAndLockNo( key.GetHashCode(), out bucketNo, out lockNo, m_buckets.Length); 2: lock (m_locks[lockNo]) { 3: Node headNode = m_buckets[bucketNo]; 4: Mutate the node linked list as appropriate } } For example, when adding another entry to the dictionary, you would iterate through the linked list to check whether the key exists already, and add the new entry as the head node. When removing items, you would find the entry to remove (if it exists), and remove the node from the linked list. Adding, updating, and removing items all follow this pattern. Performance issues There is a problem we have to address at this point. If the number of buckets in the dictionary is fixed in the constructor, then the performance will degrade from O(1) to O(n) when a large number of items are added to the dictionary. As more and more items get added to the linked lists in each bucket, the lookup operations will spend most of their time traversing a linear linked list. To fix this, the buckets array has to be resized once the number of items in each bucket has gone over a certain limit. (In ConcurrentDictionary this limit is when the size of the largest bucket is greater than the number of buckets for each lock. This check is done at the end of the TryAddInternal method.) Resizing the bucket array and re-hashing everything affects every bucket in the collection. Therefore, this operation needs to take out every lock in the collection. Taking out mutiple locks at once inevitably summons the spectre of the deadlock; two threads each hold a lock, and each trying to acquire the other lock. How can we eliminate this? Simple - ensure that threads never try to 'swap' locks in this fashion. When taking out multiple locks, always take them out in the same order, and always take out all the locks you need before starting to release them. In ConcurrentDictionary, this is controlled by the AcquireLocks, AcquireAllLocks and ReleaseLocks methods. Locks are always taken out and released in the order they are in the m_locks array, and locks are all released right at the end of the method in a finally block. At this point, it's worth pointing out that the locks array is never re-assigned, even when the buckets array is increased in size. The number of locks is fixed in the constructor by the concurrencyLevel parameter. This simplifies programming the locks; you don't have to check if the locks array has changed or been re-assigned before taking out a lock object. And you can be sure that when a thread takes out a lock, another thread isn't going to re-assign the lock array. This would create a new series of lock objects, thus allowing another thread to ignore the existing locks (and any threads controlling them), breaking thread-safety. Consequences of growing the array Just because we're using locks doesn't mean that race conditions aren't a problem. We can see this by looking at the GrowTable method. The operation of this method can be boiled down to: private void GrowTable(Node[] buckets) { try { 1: Acquire first lock in the locks array // this causes any other thread trying to take out // all the locks to block because the first lock in the array // is always the one taken out first // check if another thread has already resized the buckets array // while we were waiting to acquire the first lock 2: if (buckets != m_buckets) return; 3: Calculate the new size of the backing array 4: Node[] array = new array[size]; 5: Acquire all the remaining locks 6: Re-hash the contents of the existing buckets into array 7: m_buckets = array; } finally { 8: Release all locks } } As you can see, there's already a check for a race condition at step 2, for the case when the GrowTable method is called twice in quick succession on two separate threads. One will successfully resize the buckets array (blocking the second in the meantime), when the second thread is unblocked it'll see that the array has already been resized & exit without doing anything. There is another case we need to consider; looking back at the AlterBucket method above, consider the following situation: Thread 1 calls AlterBucket; step 1 is executed to get the bucket and lock numbers. Thread 2 calls GrowTable and executes steps 1-5; thread 1 is blocked when it tries to take out the lock in step 2. Thread 2 re-hashes everything, re-assigns the buckets array, and releases all the locks (steps 6-8). Thread 1 is unblocked and continues executing, but the calculated bucket and lock numbers are no longer valid. Between calculating the correct bucket and lock number and taking out the lock, another thread has changed where everything is. Not exactly thread-safe. Well, a similar problem was solved in ConcurrentStack and ConcurrentQueue by storing a local copy of the state, doing the necessary calculations, then checking if that state is still valid. We can use a similar idea here: void AlterBucket(TKey key, ...) { while (true) { Node[] buckets = m_buckets; int bucketNo, lockNo; GetBucketAndLockNo( key.GetHashCode(), out bucketNo, out lockNo, buckets.Length); lock (m_locks[lockNo]) { // if the state has changed, go back to the start if (buckets != m_buckets) continue; Node headNode = m_buckets[bucketNo]; Mutate the node linked list as appropriate } break; } } TryGetValue and GetEnumerator And so, finally, we get onto TryGetValue and GetEnumerator. I've left these to the end because, well, they don't actually use any locks. How can this be? Whenever you change a bucket, you need to take out the corresponding lock, yes? Indeed you do. However, it is important to note that TryGetValue and GetEnumerator don't actually change anything. Just as immutable objects are, by definition, thread-safe, read-only operations don't need to take out a lock because they don't change anything. All lockless methods can happily iterate through the buckets and linked lists without worrying about locking anything. However, this does put restrictions on how the other methods operate. Because there could be another thread in the middle of reading the dictionary at any time (even if a lock is taken out), the dictionary has to be in a valid state at all times. Every change to state has to be made visible to other threads in a single atomic operation (all relevant variables are marked volatile to help with this). This restriction ensures that whatever the reading threads are doing, they never read the dictionary in an invalid state (eg items that should be in the collection temporarily removed from the linked list, or reading a node that has had it's key & value removed before the node itself has been removed from the linked list). Fortunately, all the operations needed to change the dictionary can be done in that way. Bucket resizes are made visible when the new array is assigned back to the m_buckets variable. Any additions or modifications to a node are done by creating a new node, then splicing it into the existing list using a single variable assignment. Node removals are simply done by re-assigning the node's m_next pointer. Because the dictionary can be changed by another thread during execution of the lockless methods, the GetEnumerator method is liable to return dirty reads - changes made to the dictionary after GetEnumerator was called, but before the enumeration got to that point in the dictionary. It's worth listing at this point which methods are lockless, and which take out all the locks in the dictionary to ensure they get a consistent view of the dictionary: Lockless: TryGetValue GetEnumerator The indexer getter ContainsKey Takes out every lock (lockfull?): Count IsEmpty Keys Values CopyTo ToArray Concurrent principles That covers the overall implementation of ConcurrentDictionary. I haven't even begun to scratch the surface of this sophisticated collection. That I leave to you. However, we've looked at enough to be able to extract some useful principles for concurrent programming: Partitioning When using locks, the work is partitioned into independant chunks, each with its own lock. Each partition can then be modified concurrently to other partitions. Ordered lock-taking When a method does need to control the entire collection, locks are taken and released in a fixed order to prevent deadlocks. Lockless reads Read operations that don't care about dirty reads don't take out any lock; the rest of the collection is implemented so that any reading thread always has a consistent view of the collection. That leads us to the final collection in this little series - ConcurrentBag. Lacking a non-concurrent analogy, it is quite different to any other collection in the class libraries. Prepare your thinking hats!

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• CodePlex Daily Summary for Monday, June 11, 2012

  CodePlex Daily Summary for Monday, June 11, 2012Popular ReleasesCasanova Language: Casanova IDE alpha release: This is the first release for the Casanova IDE. It features the major capabilities of the framework: support for rules, scripts, input management, and basic content management. The IDE is still under major development. Planned features include: multiplayer support 3D rendering syntax highlighting basic Intellisense slightly improved syntax for rules and scripts audio in-game menus Also, do not forget to download and install OpenAL: http://connect.creativelabs.com/openal/Download...Liberty: v3.2.1.0 Release 10th June 2012: Change Log -Added -Liberty is now digitally signed! If the certificate on Liberty.exe is missing, invalid, or does not state that it was developed by "Xbox Chaos, Open Source Developer," your copy of Liberty may have been altered in some (possibly malicious) way. -Reach Mass biped max health and shield changer -Fixed -H3/ODST Fixed all of the glitches that users kept reporting (also reverted the changes made in 3.2.0.2) -Reach Made some tag names clearer and more consistent between m...SVNUG.CodePlex: Cloud Development with Windows Azure: This release contains the slides for the Cloud Development with Windows Azure presentation.WCF Data Service (OData) Regression & Load Testing Tool: Latest: This is latest stable releaseSHA-1 Hash Checker: SHA-1 Hash Checker (for Windows): Fixed major bugs. Removed false negatives.AutoUpdaterdotNET: AutoUpdater.NET 1.0: Everything seems perfect if you find any problem you can report to http://www.rbsoft.org/contact.htmlMedia Companion: Media Companion 3.503b: It has been a while, so it's about time we release another build! Major effort has been for fixing trailer downloads, plus a little bit of work for episode guide tag in TV show NFOs.Microsoft SQL Server Product Samples: Database: AdventureWorks Sample Reports 2008 R2: AdventureWorks Sample Reports 2008 R2.zip contains several reports include Sales Reason Comparisons SQL2008R2.rdl which uses Adventure Works DW 2008R2 as a data source reference. For more information, go to Sales Reason Comparisons report.Json.NET: Json.NET 4.5 Release 7: Fix - Fixed Metro build to pass Windows Application Certification Kit on Windows 8 Release Preview Fix - Fixed Metro build error caused by an anonymous type Fix - Fixed ItemConverter not being used when serializing dictionaries Fix - Fixed an incorrect object being passed to the Error event when serializing dictionaries Fix - Fixed decimal properties not being correctly ignored with DefaultValueHandlingLINQ Extensions Library: 1.0.3.0: New to release 1.0.3.0:Combinatronics: Combinations (unique) Combinations (with repetition) Permutations (unique) Permutations (with repetition) Convert jagged arrays to fixed multidimensional arrays Convert fixed multidimensional arrays to jagged arrays ElementAtMax ElementAtMin ElementAtAverage New set of array extension (1.0.2.8):Rotate Flip Resize (maintaing data) Split Fuse Replace Append and Prepend extensions (1.0.2.7) IndexOf extensions (1.0.2.7) Ne...????????API for .Net SDK: SDK for .Net ??? Release 1: 6?11????? ??? - ?Entities???????????EntityBase，???ToString()???????json???，??????4.0???????。2.0?3.5???！ ??? - Request????????AccessToken??????source=appkey?????。????，????????，???????public_timeline?????????。 ?? - ???ClinetLogin??????????RefreshToken???????false???。 ?? - ???RepostTimeline????Statuses???null???。 ?? - Utility?BuildPostData?，?WeiboParameter??value?NULL????????。 ??????? ??? - ??.Net 2.0/3.5/4.0????。??????VS2010??????????。VS2008????????，??????????。 ??? - ??.Net 4.0???SDK...Audio Pitch & Shift: Audio Pitch And Shift 4.5.0: Added Instruments tab for modules Open folder content feature Some bug fixesPython Tools for Visual Studio: 1.5 Beta 1: We’re pleased to announce the release of Python Tools for Visual Studio 1.5 Beta. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including: • Supports CPython, IronPython, Jython and PyPy • Python editor with advanced member, signature intellisense and refactoring • Code navigation: “Find all refs”, goto definition, and object browser • Local and remote debugging •...Circuit Diagram: Circuit Diagram 2.0 Beta 1: New in this release: Automatically flip components when placing Delete components using keyboard delete key Resize document Document properties window Print document Recent files list Confirm when exiting with unsaved changes Thumbnail previews in Windows Explorer for CDDX files Show shortcut keys in toolbox Highlight selected item in toolbox Zoom using mouse scroll wheel while holding down ctrl key Plugin support for: Custom export formats Custom import formats Open...Umbraco CMS: Umbraco CMS 5.2 Beta: The future of Umbracov5 represents the future architecture of Umbraco, so please be aware that while it's technically superior to v4 it's not yet on a par feature or performance-wise. What's new? For full details see our http://progress.umbraco.org task tracking page showing all items complete for 5.2. In a nutshellPackage Builder Starter Kits Dynamic Extension Methods Querying / IsHelpers Friendly alt template URLs Localization Various bug fixes / performance enhancements Gett...JayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.0.5: JayData is a unified data access library for JavaScript developers to query and update data from different sources like WebSQL, IndexedDB, OData, Facebook or YQL. See it in action in this 6 minutes video New features in JayData 1.0.5http://jaydata.org/blog/jaydata-1.0.5-is-here-with-authentication-support-and-more http://jaydata.org/blog/release-notes Sencha Touch 2 module (read-only)This module can be used to bind data retrieved by JayData to Sencha Touch 2 generated user interface. (exam...32feet.NET: 3.5: This version changes the 32feet.NET library (both desktop and NETCF) to use .NET Framework version 3.5. Previously we compiled for .NET v2.0. There are no code changes from our version 3.4. See the 3.4 release for more information. Changes due to compiling for .NET 3.5Applications should be changed to use NET/NETCF v3.5. Removal of class InTheHand.Net.Bluetooth.AsyncCompletedEventArgs, which we provided on NETCF. We now just use the standard .NET System.ComponentModel.AsyncCompletedEvent...Application Architecture Guidelines: Application Architecture Guidelines 3.0.7: 3.0.7Jolt Environment: Jolt v2 Stable: Many new features. Follow development here for more information: http://www.rune-server.org/runescape-development/rs-503-client-server/projects/298763-jolt-environment-v2.html Setup instructions in downloadSharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.5): New fetures:Multilingual Support Max users property in Standings Web Part Games time zone change (UTC +1) bug fix - Version 1.4 locking problem http://euro2012.codeplex.com/discussions/358262 bug fix - Field Title not found (v.1.3) German SP http://euro2012.codeplex.com/discussions/358189#post844228 Bug fix - Access is denied.for users with contribute rights Bug fix - Installing on non-English version of SharePoint Bug fix - Title Rules Installing SharePoint Euro 2012 PredictorSharePoint E...New Projects2D map editor for Game Tool Development class: This project contains a basic 2D map editor, which can read a tileset (or chipset) to create a custom map. The user can then load and save maps previously created (file format .map). ArtifexCore: ArtifexCore - a compilation of unique, original, and revamped RunUO/OrbSA projects.ASP.NET MVC 4 - Sports Store using Visual Studio 2011 Beta: This is a the output of "Sports Store" exercise in Pro ASP.NET MVC 3 Framework by Adam Freeman and Steven Sanderson. Instead of MVC 3 as recommended in the book, I have used MVC 4.clabinet: clabinet is a cloud based file cabinetCopy File Location - Explorer Shortcut: This Explorer Extension adds a shortcut menu to all files and folders to copy the full location to the Clipboard.CSSSEVER: ???????????DoodleLabyrinthLogic: A starter '100 rogues' type logic library for rogue-like buildersEasyFlash Cart Builder: EasyFlash Cart Builder is a tool for linking files together into an EasyFlash cartridge. Generic enumeration: Provides string representation of C# enumerations.Hacker Typer for WP7: This is a hackertyper.net Windows Phone based application HTML Batch Logger: This is a simple Log class that can be used in any .NET C# Console Application. You can use it to log into an HTML file, console window, or database. kinect ????????????: ???、??????????????????????、????????????????。???、??????????????????。?????????、????????????????、??????????????????。laskjdfqewr131231: example omes projectnlite web libraray: Lite Web Framework,????Page，??Ndf???WebApiNMemory - an in-memory relational database for .NET: NMemory is a lightweight in-memory relational database engine that can be hosted by .NET applications. It supports traditional database features like indexes, foreign key relations, transaction handling and isolation.NoManaComponets: A attempt at a reusable library for common tasks in XNA like avatar management, text rendering and shading. Currently abandoned.NP: network client appObject Viewer: A UserControl that can display any object.PowerPoint Graph Creator: The main purpose of this PowerPoint add-in is to help people who sometimes need to draw graphs into the PPT and then for example add some animations or want to load to existing graphs into PPT but don't have a lot of time to re-draw every thing.Project Blue Tigris: This Project aims at enabling users to control and interact with Windows without the need to touch the keyboard or the mouse, through a new user interface using gestures and voice commands. This project will utilize webcam and microphones connected to the computer when installed. This is our vision. It would be great if you join us.QTP FT Uninstaller: KnowledgeInbox QTP/FT Uninstaller is a tool designed for uninstalling HP's QuickTest Professional or Functional Testing products in one click. The tool should only be used in cases where QTP was working fine earlier and after some update or installation it stopped working. The tool scans the system registry for all files associated with QTP and deletes them. Note: Using this uninstaller may impact tools like HP Sprinter, Quality Center. You should re-install those tools also after using t...Radius Client for Microsoft® .NET Micro Framework: Client for Remote Authentication Dial In User Service (RADIUS)Regression Suite: RegressionSuite is a software test suite that incorporates measurement of the startup lag, measurement of accurate execution times, generating execution statistics, customized input distributions, and processable regression specific details as part of the regular unit tests. Essentially, RegressionSuite provides the frame-work around which the individual unit regressors are invoked (and details and statistics collected). Unit regressors are grouped into named regressor sets (or modules), a...Sern: Nothing yet.SharePoint List Number to Text Custom Column: Number to text custom column in SharePoint is a project that is useful in any financial SharePoint implementation to automatically generate the corresponding number representation in textual format, this feature is designed to be easy extended to any language and it’s initially in Arabic and English languages.you can find all related source code in download section SharpDND: A attempt to create a open source DLL for the openSRD. Designed with customization in mind if completed the tools included could build out pathfinder and other RPG rulesets.SmartSense: SmartSense is a wearable holographic gesture and voice controlled intelligent system. Human-computer interaction (HCI) is a heavily researched area in today’s technology driven world. Most people experience HCI using a mouse and keyboard as input devices. We wanted a more natural way to interact with the computer that also allows instant access to information. We are developing a real-time system that is always on and available to collect data at any moment but also is accessible “on-the-fly...Sumzlib: sumzlib is a set of class library that provides useful algorithms in static method. this project is written in vb.netWCF Data Service (OData) Regression & Load Testing Tool: This is a tool that is especially being developed to regress OData Services. Current release only support few test like ($select, Top, etc ), more test will be added over the time. It is a Multithreaded Regression Test Tool that can generate result in Excel format including diagnostic error data and performance data like turnaround time as well. It can be used for bulk testing of several services at the same time It can be quite useful to for those who are developing several service...X.Web.Microdata: This project is intended to represent an mitcrodata entitie in the .NET Framework. (Particularly in ASP.NET) The X.Web.Microdata represent the http://www.data-vocabulary.org/ (and Google) microdata notation And X.Web.Microdata.SchemaOrg represent http://schema.org/ microdata notatio

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• .NET Code Evolution

  - by Alois Kraus

  Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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• mysql: Bind on unix socket: Permission denied

  - by Alex

  Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases from /srv/mysql/myDB 120222 13:40:54 mysqld_safe mysqld from pid file /srv/mysql/pids/mysqld-myDB.pid ended /srv/mysql/logs/mysqld-myDB.log: 120222 13:43:53 mysqld_safe Starting mysqld daemon with databases from /srv/mysql/myDB 120222 13:43:53 [Note] Plugin 'FEDERATED' is disabled. /usr/sbin/mysqld: Table 'plugin' is read only 120222 13:43:53 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it. 120222 13:43:53 InnoDB: Completed initialization of buffer pool 120222 13:43:53 InnoDB: Started; log sequence number 32 4232720908 120222 13:43:53 [ERROR] Can't start server : Bind on unix socket: Permission denied 120222 13:43:53 [ERROR] Do you already have another mysqld server running on socket: /srv/mysql/sockets/mysql-myDB.sock ? 120222 13:43:53 [ERROR] Aborting 120222 13:43:53 InnoDB: Starting shutdown... One instance mysqld is running: $ ps aux | grep mysql mysql 1093 0.0 0.2 169972 18700 ? Ssl 11:50 0:02 /usr/sbin/mysqld $ Port 3700 is available: $ netstat -a | grep 3700 $ Directory with sockets is empty: $ ls /srv/mysql/sockets/ $ There are all permissions: $ ls -l /srv/mysql/ total 20 drwxrwxrwx 2 mysql mysql 4096 2012-02-22 13:28 logs drwxrwxrwx 13 mysql mysql 4096 2012-02-22 13:44 myDB drwxrwxrwx 2 mysql mysql 4096 2012-02-22 12:55 pids drwxrwxrwx 2 mysql mysql 4096 2012-02-22 12:55 sockets drwxrwxrwx 2 mysql mysql 4096 2012-02-22 13:25 version Apparmor config: $cat /etc/apparmor.d/usr.sbin.mysqld # vim:syntax=apparmor # Last Modified: Tue Jun 19 17:37:30 2007 #include <tunables/global> /usr/sbin/mysqld flags=(complain) { #include <abstractions/base> #include <abstractions/nameservice> #include <abstractions/user-tmp> #include <abstractions/mysql> #include <abstractions/winbind> capability dac_override, capability sys_resource, capability setgid, capability setuid, network tcp, /etc/hosts.allow r, /etc/hosts.deny r, /etc/mysql/*.pem r, /etc/mysql/conf.d/ r, /etc/mysql/conf.d/* r, /etc/mysql/*.cnf r, /usr/lib/mysql/plugin/ r, /usr/lib/mysql/plugin/*.so* mr, /usr/sbin/mysqld mr, /usr/share/mysql/** r, /var/log/mysql.log rw, /var/log/mysql.err rw, /var/lib/mysql/ r, /var/lib/mysql/** rwk, /var/log/mysql/ r, /var/log/mysql/* rw, /{,var/}run/mysqld/mysqld.pid w, /{,var/}run/mysqld/mysqld.sock w, /srv/mysql/ r, /srv/mysql/** rwk, /sys/devices/system/cpu/ r, # Site-specific additions and overrides. See local/README for details. #include <local/usr.sbin.mysqld> } Any suggestions? UPD1: $ touch /srv/mysql/sockets/mysql-myDB.sock $ sudo chown mysql:mysql /srv/mysql/sockets/mysql-myDB.sock $ ls -l /srv/mysql/sockets/mysql-myDB.sock -rw-rw-r-- 1 mysql mysql 0 2012-02-22 14:29 /srv/mysql/sockets/mysql-myDB.sock $ sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 14:30:18 mysqld_safe Can't log to error log and syslog at the same time. Remove all --log-error configuration options for --syslog to take effect. 120222 14:30:18 mysqld_safe Logging to '/srv/mysql/logs/mysqld-myDB.log'. 120222 14:30:18 mysqld_safe Starting mysqld daemon with databases from /srv/mysqlmyDB 120222 14:30:24 mysqld_safe mysqld from pid file /srv/mysql/pids/mysqld-myDB.pid ended $ ls -l /srv/mysql/sockets/mysql-myDB.sock ls: cannot access /srv/mysql/sockets/mysql-myDB.sock: No such file or directory $ UPD2: $ sudo netstat -lnp | grep mysql tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1093/mysqld unix 2 [ ACC ] STREAM LISTENING 5912 1093/mysqld /var/run/mysqld/mysqld.sock $ sudo lsof | grep /srv/mysql/sockets/mysql-myDB.sock lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/sears/.gvfs Output information may be incomplete. UPD3: $ cat /etc/mysql/my.cnf # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/run/mysqld/mysqld.sock # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] # # * Basic Settings # # # * IMPORTANT # If you make changes to these settings and your system uses apparmor, you may # also need to also adjust /etc/apparmor.d/usr.sbin.mysqld. # user = mysql socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. #bind-address = 127.0.0.1 # # * Fine Tuning # key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # * Query Cache Configuration # query_cache_limit = 1M query_cache_size = 16M # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 log_error = /var/log/mysql/error.log # Here you can see queries with especially long duration #log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. #server-id = 1 #log_bin = /var/log/mysql/mysql-bin.log expire_logs_days = 10 max_binlog_size = 100M #binlog_do_db = include_database_name #binlog_ignore_db = include_database_name # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/

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• Backing up my data causes my server to crash using Symantec Backup Exec 12, or How I Came to Loathe

  - by Kyle Noland

  I have a Dell PowerEdge 2850 running Windows Server 2003. It is the primary file server for one of my clients. I have another server also running Windows Server 2003 that acts as the core media server for Symantec Backup Exec 12. I recently upgraded from Backup Exec 11d to 12. This upgrade was necessary because we also just upgraded from Exchange 2003 to Exchange 2007. After the upgrade I had to push-install the new version 12 Backup Exec Remote Agents to each of the servers I am backing up (about 6 total). 5 of my servers are doing just fine, faithfully completing backups every night. My file server routinely crashes. Observations: When the server crashes, it does not blue screen, it just locks up completely. Even the mouse is unresponsive. If you leave the server locked up long enough, it will eventually reboot itself and hang on the Windows splash screen. There is absolutely zero useful Event Viewer evidence of a problem. The logs go from routine logging to an Unexplained Shutdown Event the next morning when I have to hard reset the server to get it to boot. 90% of the time the server does not boot cleanly, it hangs on the Windows splash screen. I don't have any light to shed here. When the server hangs all I can do is hard reset it and try again. Even after a successful boot and chkdsk /r operation, if you reboot the machine, you have a 90% chance it won't back up again cleanly. The back story: This server started crashing during nightly backups about a month ago. I tried everything I could think of to troubleshoot the problem and eventually had to give up because I could not keep coming to the office at 4 AM to try to get the server back online. One Friday I got lucky and the server stayed up for its entire full backup. I took this opportunity to restore the full backup to a temporary server I set up and switched all my users to the temporary. Then I reloaded the ailing file server. I kept all my users on the temporary file server for about 3 weeks. I installed the same Backup Exec Remote Agent and Trend Micro A/V client on the temporary server that I was using on the regular file server. During this time, I had absolutely no problems backing up the temporary server. I tested the reloaded file server extensively. I rebooted the server once an hour every day for 3 weeks trying to make it fail. It never did. I felt confident that the reload was the answer to my problems. I moved all of the data from the temporary server back to the regular server. I got 3 nightly backups out of it before it locked up again and started the familiar failure to boot cleanly behavior. This weekend I decided to monitor the file server through the entire backup job. I RDPd into the file server and also into the server running Backup Exec. On the file server I opened the Task Manager so I could view the processes and watch CPU and memory usage. Everything was running smoothly for about 60GB worth of backup. Then I noticed that the byte count of the backup job in Backup Exec had stopped progressing. I looked back over at my RDP session into the file server, and I was getting real time updates about CPU and memory usage still - both nearly 0%, which is unusual. Backups usually hover around 40% usage for the duration of the backup job. Let me reiterate this point: The screen was refreshing and I was getting real time Task Manager updates - until I clicked on the Start menu. The screen went black and the server locked up. In truth, I think the server had already locked up, the video card just hadn't figured it out yet. I went back into my bag of trick: driving to the office and hard reseting the server over and over again when it hangs up at the Windows splash screen. I did this for 2 hours without getting a successful boot. I started panicking because I did not have a decent backup to use to get everything back onto the working temporary file server. Once I exhausted everything I knew to do, I took a deep breath, booted to the Windows Server 2003 CD and performed a repair installation of Windows. The server came back up fine, with all of my data intact. I can now reboot the server at will and it will come back up cleanly. The problem is that I'm afraid as soon as I try to back that data up again I will back at square one. So let me sum things up: Here is what I've done so far to troubleshoot this server: Deleted and recreated the RAID 5 sets. Initialized the drives. Reloaded the server with a fresh Server 2003 install. Confirmed with Dell that I have installed the latest, Dell approved BIOS and NIC drivers. Uninstalled / reinstalled the Backup Exec Remote Agent. Uninstalled the Trend Micro A/V client. Configured the server not to reboot itself after a blue screen so I can see any stop error. I used to think the server was blue screening, but since I enabled this setting I now know that the server just completely locks up. Run chkdsk /r from the Windows Recovery Console. Several errors were found and corrected, but did not help my problem. Help confirm or deny the following assumptions: There are two problems at work here. Why the server is locking up in the first place, and why the server won't boot cleanly after a lockup. This is ultimately a software problem. The server works fine and can be rebooted cleanly all day long - until the first lockup - following a fresh OS load or even a Repair installation. This is not a problem with Backup Exec in general. All of my other servers back up just fine. For the record, all of the other servers run Server 2003, and some of them house more data than the file server in question here. Any help is appreciated. The irony is almost too much to bear. Backing up my data is what is jeopardizing it.

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