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  • Téléchargez gratuitement l'ebook sur le développement d'applications 'Threaded' qui utilisent le har

    Téléchargez gratuitement l'ebook sur le développement d'applications ?Threaded' Les logiciels de développement Intel® Parallel Studio accélèrent le développement d'applications ?Threaded' qui utilisent le hardware des utilisateurs finaux, depuis le ?'supercomputer'' jusqu'à l'ordinateur portable ou les mobiles. Optimisez la performance de votre application sur architecture Intel® et obtenez plus des derniers processeurs multi-coeurs d'Intel®. Depuis la manière dont les produits fonctionnent ensemble jusqu'à leurs jeux de fonctionnalités uniques, le Threading est maintenant plus facile et plus viable que jamais. Les outils sont optimisés donc les novices peuvent facilement se former et les développeurs expérimentés peuvent aisément ...

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  • What is the way to understand someone else's giant uncommented spaghetti code? [closed]

    - by Anisha Kaul
    Possible Duplicate: I’ve inherited 200K lines of spaghetti code — what now? I have been recently handled a giant multithreaded program with no comments and have been asked to understand what it does, and then to improve it (if possible). Are there some techniques which should be followed when we need to understand someone else's code? OR do we straightaway start from the first function call and go on tracking next function calls? C++ (with multi-threading) on Linux

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  • Téléchargez gratuitement l'ebook sur le développement d'applications 'Threaded' qui utilisent le har

    Téléchargez gratuitement l'ebook sur le développement d'applications ?Threaded' Les logiciels de développement Intel® Parallel Studio accélèrent le développement d'applications ?Threaded' qui utilisent le hardware des utilisateurs finaux, depuis le ?'supercomputer'' jusqu'à l'ordinateur portable ou les mobiles. Optimisez la performance de votre application sur architecture Intel® et obtenez plus des derniers processeurs multi-coeurs d'Intel®. Depuis la manière dont les produits fonctionnent ensemble jusqu'à leurs jeux de fonctionnalités uniques, le Threading est maintenant plus facile et plus viable que jamais. Les outils sont optimisés donc les novices peuvent facilement se former et les développeurs expérimentés peuvent aisément ...

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  • Visual Basic Book Excerpt: Useful Namespaces

    This chapter provides an overview of some of the most important system namespaces and gives more detailed examples that demonstrate regular expressions, XML, cryptography, reflection, threading, parallel programming, and Direct3D....Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • How would you rank these programming skills in order of learning them? [closed]

    - by mumtaz
    As a general purpose programmer, what should you learn first and what should you learn later on? Here are some skills I wonder about... SQL Regular Expressions Multi-threading / Concurrency Functional Programming Graphics The mastery of your mother programming language's syntax/semantics/featureset The mastery of your base class framework libraries Version Control System Unit Testing XML Do you know other important ones? Please specify them... On which skills should I focus first?

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  • How would one go about integrated python into a c++ written game for the use of user-made scripts

    - by Spencer Killen
    I'm quite new to game development (not the site) and I'm currently just trying to educate myself about some certain things before I really begin working and a game. anyway, I'd like to know what basic algorithm/outline of how a game would be coded effeciently with the implementation of user coded scripts for gameplay and levels that are written in python, Is this even possible? would all the features of python be avalible? like say "multi-threading"?

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  • Intel programming "performance" books? [closed]

    - by user997112
    I vaguely remember seeing that Intel have produced a few good books, especially with regards to low latency programming, but I cannot remember the titles. Could people suggest the titles of Intel books (or ones relating to Intel products)? Examples include books on: -Intel Compiler -Intel Assembler -Any low level programming on Intel assembler -The Intel CPU architecture -Intel threading blocks library

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  • Which language and platform features really boosted your coding speed?

    - by Serge
    The question is about delivering working code faster without any regard for design, quality, maintainability, etc. Here is the list of things that help me to write and read code faster: Language: static typing, support for object-oriented and functional programming styles, embedded documentation, short compile-debug-fix cycle or REPL, automatic memory management Platform: "batteries" included (text, regex, IO, threading, networking), thriving community, tons of open-source libs Tools: IDE, visual debugger, code-completion, code navigation, refactoring

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  • The Uganda .NET Usergroup meeting for January 2011 - a look back.

    - by Malisa L. Ncube
    We had a very interesting meeting on Friday 28th last week. We had 10 attendees and two speakers. The first topic presented was Cloud Computing, presented by Allan Rwakatungu @arwakatungu who works with MTN Uganda. He gave a very brilliant outline of how Cloud computing and service oriented applications had begun changing the platform for operating business and the costs it saves because of scalability and elasticity. He went on to demonstrate the steps you would take if you are beginning a new Windows Azure project. He explained the history and evolution of the Windows Azure, SQL Azure and cloud services offered by Amazon and google.com. The attendees had many questions to ask (obviously), but they were all answered very well. We once again thank Allan, for taking time to prepare the presentation and demonstrating for us. We recorded a video on the entire presentation and after doing some editing we will publish it. One wish which was echoed by most members was that Microsoft should open the cloud services and development for Africa. Microsoft currently does not even have servers here in Africa and so far, that does not put African developers in the same platform as other developers in other continents. Now is the time considering the improvements in network speeds and joining of the Seacom network and broadband.   I presented on Parallelism and Multithreading using .NET 4.0, I also gave some details on the language changes in C# 5.0 and the async keyword and the TaskEx class. I explained the Task, Scheduling of parallel tasks and demonstrated problems that may arise from using parallelism inappropriately. I also demonstrated the performance improvements that may be achieved by taking advantage of multi-core processors. You may download the presentation on Parallelism and Multi-threading from here. The resolution of the meeting was that we should meet more than once a month and begin other activities which should be more fun. e.g. Geek Dinner, Geek Beer or CodeCamp. Based on that we all agreed we shall have a mid-month meeting starting from February. Cheers folks! del.icio.us Tags: .net,usergroup,cloud computing,parallelism,multi-threading

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  • Load Balance and Parallel Performance

    Load balancing an application workload among threads is critical to performance. However, achieving perfect load balance is non-trivial, and it depends on the parallelism within the application, workload, the number of threads, load balancing policy, and the threading implementation.

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  • OSB, Service Callouts and OQL - Part 3

    - by Sabha
    In the previous sections of the "OSB, Service Callouts and OQL" series, we analyzed the threading model used by OSB for Service Callouts and analysis of OSB Server threads hung in Service callouts and identifying  the Proxies and Remote services involved in the hang using OQL. This final section of the series will focus on the corrective action to avoid Service Callout related OSB Server hangs. Please refer to the blog post for more details.

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  • Build Web applications with HTML 5

    <b>IBM Developerworks:</b> "In this article, learn how to detect which capabilities are present and how to take advantage of those features in your application. Explore powerful HTML 5 features such as multi-threading, geolocation, embedded databases, and embedded video."

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  • Shows how to use the new Tasks namespace to download multiple documents in parallel.

    In C# 4.0, Task parallelism is the lowest-level approach to parallelization with PFX. The classes for working at this level are defined in the System.Threading.Tasks namespace.  read moreBy Peter BrombergDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • C++ Intel TBB : sortie de la version 3 de la bibliothèque open source pour le développement parallè

    La bibliothèque open source TBB d'Intel pour programmer en parallèle vient de sortir en version 3 Intel vient d'annoncer aujourd'hui la sortie de la troisième version de sa bibliothèque TBB (thread building blocks). Cette bibliothèque C++, disponible en open source, a pour objectif de permettre de programmer en parallèle, afin d'accéder aux ressources des machines multi-coeurs actuels. Citation: Today, Intel released Intel® Threading Building Blocks (Intel® TBB) 3.0, a high-level parallel programming toolkit that ...

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  • Why C++ people loves multithreading when it comes to performances?

    - by user1849534
    I have a question, it's about why programmers seems to love concurrency and multi-threaded programs in general. I'm considering 2 main approach here: an async approach basically based on signals, or just an async approach as called by many papers and languages like the new C# 5.0 for example, and a "companion thread" that maanges the policy of your pipeline a concurrent approach or multi-threading approach I will just say that I'm thinking about the hardware here and the worst case scenario, and I have tested this 2 paradigms myself, the async paradigm is a winner at the point that I don't get why people 90% of the time talk about concurrency when they wont to speed up things or make a good use of their resources. I have tested multi-threaded programs and async program on an old machine with an Intel quad-core that doesn't offer a memory controller inside the CPU, the memory is managed entirely by the motherboard, well in this case performances are horrible with a multi-threaded application, even a relatively low number of threads like 3-4-5 can be a problem, the application is unresponsive and is just slow and unpleasant. A good async approach is, on the other hand, probably not faster but it's not worst either, my application just waits for the result and doesn't hangs, it's responsive and there is a much better scaling going on. I have also discovered that a context change in the threading world it's not that cheap in real world scenario, it's infact quite expensive especially when you have more than 2 threads that need to cycle and swap among each other to be computed. On modern CPUs the situation it's not really that different, the memory controller it's integrated but my point is that an x86 CPUs is basically a serial machine and the memory controller works the same way as with the old machine with an external memory controller on the motherboard. The context switch is still a relevant cost in my application and the fact that the memory controller it's integrated or that the newer CPU have more than 2 core it's not bargain for me. For what i have experienced the concurrent approach is good in theory but not that good in practice, with the memory model imposed by the hardware, it's hard to make a good use of this paradigm, also it introduces a lot of issues ranging from the use of my data structures to the join of multiple threads. Also both paradigms do not offer any security abut when the task or the job will be done in a certain point in time, making them really similar from a functional point of view. According to the X86 memory model, why the majority of people suggest to use concurrency with C++ and not just an async aproach ? Also why not considering the worst case scenario of a computer where the context switch is probably more expensive than the computation itself ?

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  • Is a 1:* write:read thread system safe?

    - by Di-0xide
    Theoretically, thread-safe code should fix race conditions. Race conditions, as I understand it, occur because two threads attempt to write to the same location at the same time. However, what about a threading model in which a single thread is designed to write to a location, and several slave/worker threads simply read from the location? Assuming the value/timing at which they read the data isn't relevant/doesn't hinder the worker thread's outcome, wouldn't this be considered 'thread safe', or am I missing something in my logic?

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  • Help building maya render node spec

    - by Ak
    Hi there, I'm looking to build 4x Maya render slaves/nodes for a friend of mine when his project gets green lit. The project involves MentalRay and lots of glass. I'm unsure if the new i7's 9xx or 8xx with hyper threading will do any better than a core 2 quad of the same (or close enough) speed. Does hyper threading make a difference to Maya or is it more performance per core based? I'm sure he's prefer I'd build another render node than pay for a bleeding edge CPU that only adds fractionly more GHz. -- The rest of the spec so far: 4Gb - 8Gb ram 64 bit OS: Probably Windows 7 (I know Linux is free, but want to build something my friend can support himself as easily as he supports his own workstation) 1TB HDD to hold textures, Maya files and renders which will be copied to central storage later Mobo with on-board video, gigabit NIC 500 - 650 watt PSU Desktop case something like a: Cooler Master ATCS 840 The machines will sold afterwards if necessary. -- If anyone has had experience in Maya and has done any tests with the new CPUs vs. the older ones I'd really appreciate your input.

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  • How to test nginx proxy timeouts

    - by mkorszun
    Target: I would like to test all Nginx proxy timeout parameters in very simple scenario. My first approach was to create really simple HTTP server and put some timeouts: Between listen and accept to test proxy_connect_timeout Between accept and read to test proxy_send_timeout Between read and send to test proxy_read_timeout Test: 1) Server code (python): import socket import os import time import threading def http_resp(conn): conn.send("HTTP/1.1 200 OK\r\n") conn.send("Content-Length: 0\r\n") conn.send("Content-Type: text/xml\r\n\r\n\r\n") def do(conn, addr): print 'Connected by', addr print 'Sleeping before reading data...' time.sleep(0) # Set to test proxy_send_timeout data = conn.recv(1024) print 'Sleeping before sending data...' time.sleep(0) # Set to test proxy_read_timeout http_resp(conn) print 'End of data stream, closing connection' conn.close() def main(): s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.bind(('', int(os.environ['PORT']))) s.listen(1) print 'Sleeping before accept...' time.sleep(130) # Set to test proxy_connect_timeout while 1: conn, addr = s.accept() t = threading.Thread(target=do, args=(conn, addr)) t.start() if __name__ == "__main__": main() 2) Nginx configuration: I have extended Nginx default configuration by setting explicitly proxy_connect_timeout and adding proxy_pass pointing to my local HTTP server: location / { proxy_pass http://localhost:8888; proxy_connect_timeout 200; } 3) Observation: proxy_connect_timeout - Even though setting it to 200s and sleeping only 130s between listen and accept Nginx returns 504 after ~60s which might be because of the default proxy_read_timeout value. I do not understand how proxy_read_timeout could affect connection at so early stage (before accept). I would expect 200 here. Please explain! proxy_send_timeout - I am not sure if my approach to test proxy_send_timeout is correct - i think i still do not understand this parameter correctly. After all, delay between accept and read does not force proxy_send_timeout. proxy_read_timeout - it seems to be pretty straightforward. Setting delay between read and write does the job. So I guess my assumptions are wrong and probably I do not understand proxy_connect and proxy_send timeouts properly. Can some explain them to me using above test if possible (or modifying if required).

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  • CodePlex Daily Summary for Thursday, February 25, 2010

    CodePlex Daily Summary for Thursday, February 25, 2010New ProjectsAptusSoftware.Threading: AptusSoftware.Threading is a class library designed primarily to assist in the development of multi-threaded WinForm applications, although there i...AxiomGameDesigner: It is going to be a universal scene editor for Axiom 3D game engine. It is in pure C# and will be kept portable to MONO for compatibility with linu...Badger - Unity Productivity Extensions: A set of Microsoft Unity Extensions. Why Badger? Because I love badgers.Business & System Analysis Templates and Best Practices for Russian: http://saway.codeplex.com/Conectayas: Conectayas is an open source "Connect Four" alike game but transformable to "Tic-Tac-Toe" and to a lot of similar games that uses mouse. Written in...FastCode: .NET 3.5 Extensions set to increase coding speed.Hundiyas: Hundiyas is an open source "Battleship" alike game totally written in DHTML (JavaScript, CSS and HTML) that uses mouse. This cross-platform and cro...Icelandic Online Banking: Icelandic Online Banking is project defining a web service interface for online banking.IE8 AddOns XML Creator: Application that helps on creating the xml files for IE8 Accelerators, Search Providers and the markup for Web Slices.iKnowledge: a asp.net mvc demoLearn ASP.NET MVC: Learn ASP.NET MVC is a project for the members of the Peer Learning group in Silicon Valley. It contains the SportsStore solution from the Pro ASP...Live at Education Meta Web-Service: Live at Education Meta Web-Service is intended to abstract from several technologies that are included in Live@edu set of services. This web-ser...Low level wave sound output for VB.NET: Low level sound output class for VB.NET using platform invocation services to call winmm.dllMailQ: MailQ makes it easier for developers to send mail messages from an application. The system sends mails based on a database queue system (store, se...Managed DXGI: Managed DXGI library is Fully managed wrapper writen on C# for DXGI 1.0 and 1.1 technology. It makes easier to support DXGI in managed application....Multivalue AutoComplete WinForms TextBox in C#: This project is a sample application that demonstrates how to create a multivalue WinForms textbox in C# using .NET Framework 3.5.Nifty CSharp Tools: Nifty CSharp Tools, will contain various tools and snippets. IRCBot, splashscreens, linq, world of warcraft log parsing, screenshot uploaders, twi...PHP MPQ: A port of StormLib to PHP for handling Blizzard MPQ files.RedDevils strategy - Project Hoshimi Programming Battle: Source Code of RedDevils strategy. Imagine Cup 2008 - Project Hoshimi Programming Battle.RNUNIT: rNunit is a distributed Nunit project. Many application these days are client-server application, distributed application and regular unit testing ...Samar Solution: Samar Solutions is a business system for office automation.Silverlight OOMRPG Game Engine: Silverlight OOMRPG Game EngineSimulator: GPSSimulatorSLARToolkit - Silverlight Augmented Reality Toolkit: SLARToolkit is a flexible Augmented Reality library for Silverlight with the aim to make real time Augmented Reality applications with Silverlight ...Spiral Architecture Driven Development (SADD) for Russian: Это русская версия сайта sadd.codeplex.comSQLSnapshotManager: Easily manage SQL Server database snapshots in a easy to use visual interface.Twilio with VB.NET MVC: Twilio with VB.NET MVC is a sample application for developing with Twilio's REST based telephony API. It includes an XML Schema of the TwiML respon...Ultra Speed Dial: UltraSpeedDial.com - Online Speed Dial Page.Visual HTML Editor justHTML: justHTML - is simle windows-application WYSIWYG editor that allow everyone - without any knowledge of HTML - to create and edit web-pages. It supp...WinMTR.NET: .NET Clone of the popular Windows clone of the popular Linux Matt's TracerouteWPF Dialogs: "WPF Dialogs" is a library for different Dialogs in WPF (e.g. FolderBrowseDialog, SaveFileDialog, OpenFileDialog etc.). These Dialogs are written i...WPFLogin: A small Login window in WPF and C#XNA PerformanceTimers: CPU Timers for Windows and Xbox360. Can track multiple threads, and presents output as a log on-screen.New ReleasesAptusSoftware.Threading: 2.0.0: First public release. This release is in production as part of several commercial applications and is stable. The source code download includes a...BizTalk Software Factory: BizTalk Software Factory v2.1: This is a service release for the BizTalk Software Factory for BizTalk Server 2009, containing so far: Fix for x64: the SN.EXE tool is now locate...Business & System Analysis Templates and Best Practices for Russian: R00 The Place reserver: Just to reserve the place Will be filled out soonChronos WPF: Chronos v1.0 Beta 2: Added a new SplashScreen Added a new Login View and implemented Log Off Added a new PasswordBoxHelper (http://www.codeproject.com/Articles/371...dotNetTips: dotNetTips.Utility 3.5 R2: This is a new release (version 3.5.0.3) compatible with .NET 3.5. Lots of new classes/features!! Requires SP1 if using the Entity Framework extensi...fleXdoc: template-based server-side document generator (docx): fleXdoc 1.0 beta 3: The third and final beta of fleXdoc. fleXdoc consists of a webservice and a (test)client for the service. Make sure you also download the testclien...FluentPS: FluentPS v1.0: - FluentPS is moved from ASMX to WCF interface of the Project Server Interface (PSI) - Impersonation changes to work in compliance with WCF interfa...FolderSize: FolderSize.Win32.1.0.4.0: FolderSize.Win32.1.0.3.0 A simple utility intended to be used to scan harddrives for the folders that take most place and display this to the user...iTuner - The iTunes Companion: iTuner 1.1.3707 Beta 3: As promised, the iTuner Automated Librarian is now available. This automatically cleans an entire album of dead tracks and duplicates as tracks ar...Live at Education Meta Web-Service: LAEMWS v 1.0 beta: Release Candidate for LAEMWS.Macaw Reusable Code Library: LanguageConfigurationSolution: This Solution helps developing a multi language publishing web siteManaged DXGI: Initial Release.: Base declaration of interfaces, most of them untested yet.Math.NET Numerics: 2010.2.24.667 Build: Latest alpha buildMiniTwitter: 1.08.1: MiniTwitter 1.08.1 更新内容 変更 インクリメンタル検索時には大文字小文字の区別をしないように変更 クライアント名の表示を本家にあわせて from から via に変更 修正 公式 RT 時にステータスが上に表示されたり二重に表示されるバグを修正 自分が自分へ返信...Multivalue AutoComplete WinForms TextBox in C#: 1.0 First public release: Multivalue autocomplete textbox control and host application in this release are released in a single Visual Studio 2008 projects. See my related b...NMock3: NMock3 - Beta3, .NET 3.5: This release has some exciting new features. Please start providing feedback on the tutorials. The first several are complete and the rest are no...nxAjax - an asp.net ajax library using jQuery: nxAjax v3 codeplex 7: nxAjax v3 codeplex 7 binary and test website. Bug Fixed: ajax:Form control Add: Drag and drop Rewritten: DragnDropManager DragPanel DropPan...Office Apps: 0.8.7: whats new? Document.Editor and Document.Viewer now supports FlowDocument (.xaml) files bug fix'sPDF Rider: PDF Rider 0.3: Application PrerequisitesMicrosoft Windows Operating Systems (XP (tested) - Vista - 7) Microsoft .NET Framework 3.5 runtime A PDF rendering sof...ShellLight: ShellLight 0.1.0.1 Src: Codeplex project released. This is only a preview of the product. Until the first final release there will be many improvements.Silverlight OOMRPG Game Engine: SilverlightGameTutorialSolution v1.01: Please visit my blog for Silverlight OOMROG Game Tutorial: http://www.cnblogs.com/Jax/archive/2010/02/24/1673053.html.Simple Savant: Simple Savant v0.4: Added support for full-text indexing (See Full-Text Indexing) Added support for attribute spanning and compression for property values larger tha...Spiral Architecture Driven Development (SADD) for Russian: R00: R00 to reserve site nameTeamReview - TFS Code Review: Release 1.1.3: Release Features New expanded product positioning for capturing any targeted coding work as a trackable, assignable, reportable Work Item for any r...Text Designer Outline Text Library: 10th minor release: Version 0.3.1 (10th minor release)Fixed the gradient brush being too big for the text, resulting in not much gradient shown in the text. Gradient...TFS Workflow Control: TeamExplorer and TSWA control 1.0 for TFS 2010 RC: This is a special version for TFS 2010 RC. Use the RC version of the power tools to modify the layout of your work items (http://visualstudiogaller...thinktecture WSCF.blue: WSCF.blue V1 Update (1.0.7) - VS2010 RC Support: This update adds support for Visual Studio 2010 RC in addition to Visual Studio 2008. Please note that Visual Studio 2010 Beta 2 is NOT supported a...Tumblen3: tumblen3 Version 25Feb2010: ready for Twitter's xAuthUMD文本编辑器: UMDEditor文本编辑器V2.1.0: 2.1.0 (2010-02-24) 增加查找章节内指定文本内容的功能 2.0.4 (2010-02-06) 章节内容框增加右键菜单,包含编辑文本的基本操作 ------------------------------------------------------- 执行 reg.bat ...VCC: Latest build, v2.1.30224.0: Automatic drop of latest buildVisual HTML Editor justHTML: Latest binary: Latest buid here. Executable and mshtml.dll included in this archive. Ready to use ;)Visual HTML Editor justHTML: Source code for version 2.5: Visual studio 2008 project with full source code.VOB2MKV: vob2mkv-1.0.2: The release vob2mkv-1.0.2 is a feature update of the VOB2MKV project. It now includes a DirectShow source filter, MKVSOURCE. A source filter allo...WinMTR.NET: V 1.0: V 1.0WPF Dialogs: Version 0.1.0: Version 0.1.0 FolderBrowseDialog is implementet for more information look here Version 0.1.0 (german: Version 0.1.0 - Deutsch).WPF Dialogs: Version 0.1.1: Version 0.1.1 Features FolderBrowseDialog was extended / FolderBrowseDialog - Deutsch wurde erweitertXNA PerformanceTimers: XNA PerformanceTimers 0.1: Initial release.Zeta Resource Editor: Release 2010-02-24: Added HTTP proxy server support.Most Popular ProjectsASP.NET Ajax LibraryManaged Extensibility FrameworkWindows 7 USB/DVD Download ToolDotNetZip LibraryMDownloaderVirtual Router - Wifi Hot Spot for Windows 7 / 2008 R2MFCMAPIDroid ExplorerUseful Sharepoint Designer Custom Workflow ActivitiesOxiteMost Active ProjectsDinnerNow.netBlogEngine.NETRawrInfoServiceSLARToolkit - Silverlight Augmented Reality ToolkitNB_Store - Free DotNetNuke Ecommerce Catalog ModuleSharpMap - Geospatial Application Framework for the CLRjQuery Library for SharePoint Web ServicesRapid Entity Framework. (ORM). CTP 2Common Context Adapters

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  • Following the Thread in OSB

    - by Antony Reynolds
    Threading in OSB The Scenario I recently led an OSB POC where we needed to get high throughput from an OSB pipeline that had the following logic: 1. Receive Request 2. Send Request to External System 3. If Response has a particular value   3.1 Modify Request   3.2 Resend Request to External System 4. Send Response back to Requestor All looks very straightforward and no nasty wrinkles along the way.  The flow was implemented in OSB as follows (see diagram for more details): Proxy Service to Receive Request and Send Response Request Pipeline   Copies Original Request for use in step 3 Route Node   Sends Request to External System exposed as a Business Service Response Pipeline   Checks Response to Check If Request Needs to Be Resubmitted Modify Request Callout to External System (same Business Service as Route Node) The Proxy and the Business Service were each assigned their own Work Manager, effectively giving each of them their own thread pool. The Surprise Imagine our surprise when, on stressing the system we saw it lock up, with large numbers of blocked threads.  The reason for the lock up is due to some subtleties in the OSB thread model which is the topic of this post.   Basic Thread Model OSB goes to great lengths to avoid holding on to threads.  Lets start by looking at how how OSB deals with a simple request/response routing to a business service in a route node. Most Business Services are implemented by OSB in two parts.  The first part uses the request thread to send the request to the target.  In the diagram this is represented by the thread T1.  After sending the request to the target (the Business Service in our diagram) the request thread is released back to whatever pool it came from.  A multiplexor (muxer) is used to wait for the response.  When the response is received the muxer hands off the response to a new thread that is used to execute the response pipeline, this is represented in the diagram by T2. OSB allows you to assign different Work Managers and hence different thread pools to each Proxy Service and Business Service.  In out example we have the “Proxy Service Work Manager” assigned to the Proxy Service and the “Business Service Work Manager” assigned to the Business Service.  Note that the Business Service Work Manager is only used to assign the thread to process the response, it is never used to process the request. This architecture means that while waiting for a response from a business service there are no threads in use, which makes for better scalability in terms of thread usage. First Wrinkle Note that if the Proxy and the Business Service both use the same Work Manager then there is potential for starvation.  For example: Request Pipeline makes a blocking callout, say to perform a database read. Business Service response tries to allocate a thread from thread pool but all threads are blocked in the database read. New requests arrive and contend with responses arriving for the available threads. Similar problems can occur if the response pipeline blocks for some reason, maybe a database update for example. Solution The solution to this is to make sure that the Proxy and Business Service use different Work Managers so that they do not contend with each other for threads. Do Nothing Route Thread Model So what happens if there is no route node?  In this case OSB just echoes the Request message as a Response message, but what happens to the threads?  OSB still uses a separate thread for the response, but in this case the Work Manager used is the Default Work Manager. So this is really a special case of the Basic Thread Model discussed above, except that the response pipeline will always execute on the Default Work Manager.   Proxy Chaining Thread Model So what happens when the route node is actually calling a Proxy Service rather than a Business Service, does the second Proxy Service use its own Thread or does it re-use the thread of the original Request Pipeline? Well as you can see from the diagram when a route node calls another proxy service then the original Work Manager is used for both request pipelines.  Similarly the response pipeline uses the Work Manager associated with the ultimate Business Service invoked via a Route Node.  This actually fits in with the earlier description I gave about Business Services and by extension Route Nodes they “… uses the request thread to send the request to the target”. Call Out Threading Model So what happens when you make a Service Callout to a Business Service from within a pipeline.  The documentation says that “The pipeline processor will block the thread until the response arrives asynchronously” when using a Service Callout.  What this means is that the target Business Service is called using the pipeline thread but the response is also handled by the pipeline thread.  This implies that the pipeline thread blocks waiting for a response.  It is the handling of this response that behaves in an unexpected way. When a Business Service is called via a Service Callout, the calling thread is suspended after sending the request, but unlike the Route Node case the thread is not released, it waits for the response.  The muxer uses the Business Service Work Manager to allocate a thread to process the response, but in this case processing the response means getting the response and notifying the blocked pipeline thread that the response is available.  The original pipeline thread can then continue to process the response. Second Wrinkle This leads to an unfortunate wrinkle.  If the Business Service is using the same Work Manager as the Pipeline then it is possible for starvation or a deadlock to occur.  The scenario is as follows: Pipeline makes a Callout and the thread is suspended but still allocated Multiple Pipeline instances using the same Work Manager are in this state (common for a system under load) Response comes back but all Work Manager threads are allocated to blocked pipelines. Response cannot be processed and so pipeline threads never unblock – deadlock! Solution The solution to this is to make sure that any Business Services used by a Callout in a pipeline use a different Work Manager to the pipeline itself. The Solution to My Problem Looking back at my original workflow we see that the same Business Service is called twice, once in a Routing Node and once in a Response Pipeline Callout.  This was what was causing my problem because the response pipeline was using the Business Service Work Manager, but the Service Callout wanted to use the same Work Manager to handle the responses and so eventually my Response Pipeline hogged all the available threads so no responses could be processed. The solution was to create a second Business Service pointing to the same location as the original Business Service, the only difference was to assign a different Work Manager to this Business Service.  This ensured that when the Service Callout completed there were always threads available to process the response because the response processing from the Service Callout had its own dedicated Work Manager. Summary Request Pipeline Executes on Proxy Work Manager (WM) Thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. Route Node Request sent using Proxy WM Thread Proxy WM Thread is released before getting response Muxer is used to handle response Muxer hands off response to Business Service (BS) WM Response Pipeline Executes on Routed Business Service WM Thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. No Route Node (Echo functionality) Proxy WM thread released New thread from the default WM used for response pipeline Service Callout Request sent using proxy pipeline thread Proxy thread is suspended (not released) until the response comes back Notification of response handled by BS WM thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. Note this is a very short lived use of the thread After notification by callout BS WM thread that thread is released and execution continues on the original pipeline thread. Route/Callout to Proxy Service Request Pipeline of callee executes on requestor thread Response Pipeline of caller executes on response thread of requested proxy Throttling Request message may be queued if limit reached. Requesting thread is released (route node) or suspended (callout) So what this means is that you may get deadlocks caused by thread starvation if you use the same thread pool for the business service in a route node and the business service in a callout from the response pipeline because the callout will need a notification thread from the same thread pool as the response pipeline.  This was the problem we were having. You get a similar problem if you use the same work manager for the proxy request pipeline and a business service callout from that request pipeline. It also means you may want to have different work managers for the proxy and business service in the route node. Basically you need to think carefully about how threading impacts your proxy services. References Thanks to Jay Kasi, Gerald Nunn and Deb Ayers for helping to explain this to me.  Any errors are my own and not theirs.  Also thanks to my colleagues Milind Pandit and Prasad Bopardikar who travelled this road with me. OSB Thread Model Great Blog Post on Thread Usage in OSB

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  • "Unable to read data from the transport connection: net_io_connectionclosed." - Windows Vista Busine

    - by John DaCosta
    Unable to test sending email from .NET code in Windows Vista Business. I am writing code which I will migrate to an SSIS Package once it its proven. The code is to send an error message via email to a list of recipients. The code is below, however I am getting an exception when I execute the code. I created a simple class to do the mailing... the design could be better, I am testing functionality before implementing more robust functionality, methods, etc. namespace LabDemos { class Program { static void Main(string[] args) { Mailer m = new Mailer(); m.test(); } } } namespace LabDemos { class MyMailer { List<string> _to = new List<string>(); List<string> _cc = new List<string>(); List<string> _bcc = new List<string>(); String _msgFrom = ""; String _msgSubject = ""; String _msgBody = ""; public void test(){ //create the mail message MailMessage mail = new MailMessage(); //set the addresses mail.From = new MailAddress("[email protected]"); //set the content mail.Subject = "This is an email"; mail.Body = "this is a sample body"; mail.IsBodyHtml = false; //send the message SmtpClient smtp = new SmtpClient(); smtp.Host = "emailservername"; smtp.Port = 25; smtp.UseDefaultCredentials = true; smtp.Send(mail); } } Exception Message Inner Exception {"Unable to read data from the transport connection: net_io_connectionclosed."} Stack Trace " at System.Net.Mail.SmtpReplyReaderFactory.ProcessRead(Byte[] buffer, Int32 offset, Int32 read, Boolean readLine)\r\n at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine)\r\n at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller)\r\n at System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port)\r\n at System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port)\r\n at System.Net.Mail.SmtpClient.GetConnection()\r\n at System.Net.Mail.SmtpClient.Send(MailMessage message)" Outer Exception System.Net.Mail.SmtpException was unhandled Message="Failure sending mail." Source="System" StackTrace: at System.Net.Mail.SmtpClient.Send(MailMessage message) at LabDemos.Mailer.test() in C:\Users\username\Documents\Visual Studio 2008\Projects\LabDemos\LabDemos\Mailer.cs:line 40 at LabDemos.Program.Main(String[] args) in C:\Users\username\Documents\Visual Studio 2008\Projects\LabDemos\LabDemos\Program.cs:line 48 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args) at System.Runtime.Hosting.ManifestRunner.Run(Boolean checkAptModel) at System.Runtime.Hosting.ManifestRunner.ExecuteAsAssembly() at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData) at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext) at System.Activator.CreateInstance(ActivationContext activationContext) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: System.IO.IOException Message="Unable to read data from the transport connection: net_io_connectionclosed." Source="System" StackTrace: at System.Net.Mail.SmtpReplyReaderFactory.ProcessRead(Byte[] buffer, Int32 offset, Int32 read, Boolean readLine) at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine) at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller) at System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port) at System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port) at System.Net.Mail.SmtpClient.GetConnection() at System.Net.Mail.SmtpClient.Send(MailMessage message) InnerException:

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