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  • org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be res

    - by user291750
    I've been having the following problem with my GoDaddy's server. I am using JSPs with the JSTL Library. My /WEB-INF/lib folder contains the following libraries: jstl.jar standard.jar My JSP looks something like this: <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <p>Hello! <% out.print(System.getProperty("java.class.path")); %></p> But I keep getting the following exception: org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application Any ideas as to why it is doing that? Thanks

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  • How can I judge the suitability of modern processors for systems with specific CPU requirements?

    - by Iszi
    Inspired by this question: How do I calculate clock speed in multi-core processors? The answers in the above question do a fair job of explaining why a lower-speed multi-core processor won't necessarily perform at the same level as a higher-speed single-core processor. Example: 4*2=8, but a quad-core 2 GHz processor isn't necessarily as fast as a single-core 8 GHz processor. However, I'm having a hard time putting the information in those answers to practical use in my mind. Particularly, I want to know how it should be used to judge whether a given CPU is appropriate for an application with specific requirements. Example scenarios: An application has a minimum CPU requirement of 2.4 GHz dual-core. Another application has a minimum CPU requirement of 1.8 GHz single-core. For either of the above scenarios: Would a higher-speed processor with fewer cores, or a lower-speed processor with more cores, be equally sufficient? If so, how can we determine the appropriate processor speeds required for a given number of cores?

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  • Flex and .NET - What's a good way to get data into Flex, WebORB? Web Services?

    - by JC Grubbs
    Ok, I asked a question earlier about Flex and ADO.NET Data Services but didn't get much response so I thought I'd rephrase. Does anyone have any experience building Adobe Flex applications with a .NET back-end? If so, what architecture did you use and what third-party tools if any did you employ. I've read a little about doing Flex remoting with WebORB but it seems more complicated than it should be, are web services an adequate alternative?

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  • Quad Core host with hyper-threading, how many processors to configure in VirtualBox?

    - by Anthony
    I have a quad-core i7 processor with hyperthreading (8 logical cores), when I configured a virtual machine to use 8 processors, VirtualBox gave me a warning saying that I only have four cores (which is true) and that this may cause a performance issue. But hyper-threading is a hardware feature, so the OS sees 8 cores and it sends instructions to all 8. What if setting it to 4 caused the VM to use 2 cores (4 threads) instead of 4 simultaneous threads (on all 4 cores)? Does the warning I got take into account that my machine has hyper-threading?

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  • Multi-Core Programming. Boost's MPI, OpenMP, TBB, or something else?

    - by unknownthreat
    Hello, I am totally a novice in Multi-Core Programming, but I do know how to program C++. Now, I am looking around for Multi-Core Programming library. I just want to give it a try, just for fun, and right now, I found 3 APIs, but I am not sure which one should I stick with. Right now, I see Boost's MPI, OpenMP and TBB. For anyone who have experienced with any of these 3 API (or any other API), could you please tell me the difference between these? Are there any factor to consider, like AMD or Intel architecture?

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  • What application domains are CPU bound and will tend to benefit from multi-core technologies?

    - by Glomek
    I hear a lot of people talking about the revolution that is coming in programming due to multi-core processors and parallelism, but I can't shake the feeling that for most of us, CPU cycles aren't the bottleneck. Pretty much all of my programs have been I/O bound in one way or another (database, filesystem, network, user interaction, etc.) for a very long time. Now I can think of a few areas where CPU cycles are a limiting factor, like code breaking, graphics, sound, some forms of simulation (weather, physics, etc.), and some forms of mathematical research, but they all seem like fairly specialized application domains. My general impression is that most programs are still I/O bound and that for most of our industry CPUs have been plenty fast for quite a while now. Am I off my rocker? What other application domains are CPU bound today? Do any of them include a large portion of the programming population? In essence, I'm wondering whether the multi-core CPUs will impact very many of us, and if so, how?

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  • System will only boot into a Live CD with core disabled in BIOS and ACPI off.

    - by CookieOfFortune
    I have a system that was running a Q6600 and Windows 7 RC. It crashed last night into a BSOD with a MACHINE_CHECK_EXCEPTION. Now it does that every time it boots into Windows. I tried using my Ubuntu Live CD, but the kernel would error out, the stack trace showed something along the linse of "Can not synchronized to one of the CPUs". Working from this, I enabled the "Limit CPU to 3 cores" option in my BIOS and tried again. This time, it seemed to have died after an ACPI call, so I disabled that during the boot and now it is running from the Ubuntu Live CD, showing 2 cores. Does anyone here think I have any hope or is it simply a CPU waiting to die? EDIT: 1 core now.

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  • PHP OOP singleton doesn't return object

    - by Misiur
    Weird trouble. I've used singleton multiple times but this particular case just doesn't want to work. Dump says that instance is null. define('ROOT', "/"); define('INC', 'includes/'); define('CLS', 'classes/'); require_once(CLS.'Core/Core.class.php'); $core = Core::getInstance(); var_dump($core->instance); $core->settings(INC.'config.php'); $core->go(); Core class class Core { static $instance; public $db; public $created = false; private function __construct() { $this->created = true; } static function getInstance() { if(!self::$instance) { self::$instance = new Core(); } else { return self::$instance; } } public function settings($path = null) { ... } public function go() { ... } } Error code Fatal error: Call to a member function settings() on a non-object in path It's possibly some stupid typo, but I don't have any errors in my editor. Thanks for the fast responses as always.

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  • HttpsCookieFilter - IllegalStateException: getOutputStream() has already been called for this response

    - by Mat Banik
    Following exception is thrown every once in a while and it shows up in localhost log file in tomcat log directory. If anyone know how to get rid of it, all help would be appreciated. BTW the filter is working fine I just don't know why this exception is happening. Stack trace: java.lang.IllegalStateException: getOutputStream() has already been called for this response at org.apache.catalina.connector.Response.getWriter(Response.java:611) at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198) at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112) at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:366) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:283) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:233) at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167) at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1047) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:817) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549) at javax.servlet.http.HttpServlet.service(HttpServlet.java:617) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:65) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:176) at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145) at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:381) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:368) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:119) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:57) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.access.channel.ChannelProcessingFilter.doFilter(ChannelProcessingFilter.java:109) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:109) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:169) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) //Here is the servlet I suspect is trowing the exception. at package.HttpsCookieFilter.doFilter(HttpsCookieFilter.java:38) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) at org.apache.coyote.http11.Http11NioProcessor.process(Http11NioProcessor.java:886) at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:721) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:2256) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:717) The HttpsCookieFilter class: public class HttpsCookieFilter implements Filter { private static Logger log = Logger.getLogger(HttpsCookieFilter.class); @Override public void destroy() { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { final HttpServletRequest req = (HttpServletRequest) request; final HttpServletResponse res = (HttpServletResponse) response; final HttpSession session = req.getSession(false); if (session != null) { setCookie(req, res); } try{ chain.doFilter(request, response); // <- Exception thrown from here }catch (IllegalStateException e){ log.warn("HttpsCookieFilter redirect problem! ", e); } } @Override public void init(FilterConfig arg0) throws ServletException { } private void setCookie( HttpServletRequest request, HttpServletResponse response) { Cookie cookie = new Cookie("JSESSIONID", request.getSession(false).getId()); cookie.setMaxAge(-1); cookie.setPath(getCookiePath(request)); cookie.setSecure(false); response.addCookie(cookie); } private String getCookiePath(HttpServletRequest request) { String contextPath = request.getContextPath(); return contextPath.length() > 0 ? contextPath : "/"; } } web.xml <?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd"> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <listener> <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class> </listener> <listener> <listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class> </listener> <filter> <filter-name>httpsCookieFilter</filter-name> <filter-class>com.iteezy.server.web.servlet.HttpsCookieFilter</filter-class> </filter> <filter-mapping> <filter-name>httpsCookieFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <filter> <filter-name>filterChainProxy</filter-name> <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class> </filter> <filter-mapping> <filter-name>filterChainProxy</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> ... The reason for integrating this filter comes from Spring security FAQs: I'm using Tomcat (or some other servlet container) and have enabled HTTPS for my login page, switching back to HTTP afterwards. It doesn't work - I just end up back at the login page after authenticating. This happens because sessions created under HTTPS, for which the session cookie is marked as “secure”, cannot subsequently be used under HTTP. The browser will not send the cookie back to the server and any session state will be lost (including the security context information). Starting a session in HTTP first should work as the session cookie won't be marked as secure.

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  • How can I check for GPS support in-App to add a feature for those with Location services enabled?

    - by Brian Lacy
    How can I check for GPS support in-App to add a feature for those with Location services enabled? My concern is, I know I'd have to specify the tag in the manifest to declare that the app uses location services, but I still want the app to function for those without. I just want to check and, if the service is available, use it; otherwise just ignore that one feature. Thanks.

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  • BeanCreationException in Spring Framework .WAR deploy to Tomcat 6 on Ubuntu 9.10

    - by JediPotPie
    I am in the process of switching from a Windows box to Ubunutu and I want to run my own local instance of Tomcat 6. I have installed Tomcat 6 without any basic issues. When I try to deploy a .war file that I had running on the Tomcat 6 instance on my Windows box I am getting the following error.... Apr 26, 2010 3:30:27 PM org.apache.catalina.core.ApplicationContext log INFO: Initializing Spring root WebApplicationContext Apr 26, 2010 3:30:27 PM org.apache.catalina.core.StandardContext listenerStart SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.ameren.eam.ldap.LdapDAONovellImpl] for bean with name 'testNovellDao' defined in ServletContext resource [/WEB-INF/applicationContext.xml]; nested exception is java.lang.ClassNotFoundException: com.ameren.eam.ldap.LdapDAONovellImpl at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1173) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:479) at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:787) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:393) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:736) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:369) at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:261) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:45) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3934) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4429) at org.apache.catalina.manager.ManagerServlet.start(ManagerServlet.java:1249) at org.apache.catalina.manager.HTMLManagerServlet.start(HTMLManagerServlet.java:612) at org.apache.catalina.manager.HTMLManagerServlet.doGet(HTMLManagerServlet.java:136) at javax.servlet.http.HttpServlet.service(HttpServlet.java:617) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAsPrivileged(Subject.java:537) at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:301) at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:162) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:283) at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:56) at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:189) at java.security.AccessController.doPrivileged(Native Method) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:185) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:525) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454) at java.lang.Thread.run(Thread.java:636) Caused by: java.lang.ClassNotFoundException: com.ameren.eam.ldap.LdapDAONovellImpl at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1399) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1245) at org.springframework.util.ClassUtils.forName(ClassUtils.java:230) at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:381) at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1170) ... 40 more The class that is not being found is located at /WEB-INF/classes/com/ameren/eam/ldap/LdapDAONovellImpl.class relative to /WEB-INF/applicationContext.xml. I cannot figure out why it cannot find the class? Any ideas would be great.

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  • ANSI C as core of a C# project? Is this possible?

    - by Nektarios
    I'm writing a NON-GUI app which I want to be cross platform between OS X and Windows. I'm looking at the following architecture, but I don't know if it will work on the windows side: (Platform specific entry point) - ANSI C main loop = ANSI C model code doing data processing / logic = (Platform specific helpers) So the core stuff I'm planning to write in regular ANSI C, because A) it should be platform independent, B) I'm extremely comfortable with C, C) It can do the job and do it well (Platform specific entry point) can be written in whatever necessary to get the job done, this is a small amount of code, doesn't matter to me. (Platform specific helpers) is the sticky thing. This is stuff like parsing XML, accessing databases, graphics toolkit stuff, whatever. Things that aren't easy in C. Things that modern languages/frameworks will give for free. On OS X this code will be written in Objective-C interfacing with Cocoa. On Windows I'm thinking my best bet is to use C# So on Windows my architecture (simplified) looks like (C# or C?) - ANSI C - C# Is this possible? Some thoughts/suggestions so far.. 1) Compile my C core as a .dll -- this is fine, but seems there's no way to call my C# helpers unless I can somehow get function pointers and pass them to my core, but that seems unlikely 2) Compile a C .exe and a C# .exe and have them talk via shared memory or some kind of IPC. I'm not entirely opposed to this but it obviously introduces a lot of complexity so it doesn't seem ideal 3) Instead of C# use C++, it gets me some nice data management stuff and nice helper code. And I can mix it pretty easily. And the work I do could probably easily port to Linux. But I really don't like C++, and I don't want this to turn in to a 3rd-party-library-fest. Not that it's a huge deal, but it's 2010.. anything for basic data management should be built in. And targetting Linux is really not a priority. Note that no "total" alternatives are OK as suggested in other similar questions on SO I've seen; java, RealBasic, mono.. this is an extremely performance intensive application doing soft realtime for game/simulation purposes, I need C & friends here to do it right (maybe you don't, but I do)

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  • What strategies are efficient to handle concurrent reads on heterogeneous multi-core architectures?

    - by fabrizioM
    I am tackling the challenge of using both the capabilities of a 8 core machine and a high-end GPU (Tesla 10). I have one big input file, one thread for each core, and one for the the GPU handling. The Gpu thread, to be efficient, needs a big number of lines from the input, while the Cpu thread needs only one line to proceed (storing multiple lines in a temp buffer was slower). The file doesn't need to be read sequentially. I am using boost. My strategy is to have a mutex on the input stream and each thread locks - unlocks it. This is not optimal because the gpu thread should have a higher precedence when locking the mutex, being the fastest and the most demanding one. I can come up with different solutions but before rush into implementation I would like to have some guidelines. What approach do you use / recommend ?

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  • Why do different versions of Silverlight assemblies have the same version number?

    - by Simon
    Why do different versions of Silverlight assemblies have the same version number? Location: ...\Silverlight\v3.0\System.Core.dll Name: System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e Location: ...\Silverlight\v4.0\System.Core.dll Name: System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e Location: ...\Silverlight\v4.0\Profile\WindowsPhone\System.Core.dll Name: System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e While standard .net has different version numbers Location: ...\Framework\v4.0.30319\System.dll Name: System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Location: ...\Framework\v2.0.50727\System.dll Name: System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089

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  • Why does OpenGL's glDrawArrays() fail with GL_INVALID_OPERATION under Core Profile 3.2, but not 3.3 or 4.2?

    - by metaleap
    I have OpenGL rendering code calling glDrawArrays that works flawlessly when the OpenGL context is (automatically / implicitly obtained) 4.2 but fails consistently (GL_INVALID_OPERATION) with an explicitly requested OpenGL core context 3.2. (Shaders are always set to #version 150 in both cases but that's beside the point here I suspect.) According to specs, there are only two instances when glDrawArrays() fails with GL_INVALID_OPERATION: "if a non-zero buffer object name is bound to an enabled array and the buffer object's data store is currently mapped" -- I'm not doing any buffer mapping at this point "if a geometry shader is active and mode? is incompatible with [...]" -- nope, no geometry shaders as of now. Furthermore: I have verified & double-checked that it's only the glDrawArrays() calls failing. Also double-checked that all arguments passed to glDrawArrays() are identical under both GL versions, buffer bindings too. This happens across 3 different nvidia GPUs and 2 different OSes (Win7 and OSX, both 64-bit -- of course, in OSX we have only the 3.2 context, no 4.2 anyway). It does not happen with an integrated "Intel HD" GPU but for that one, I only get an automatic implicit 3.3 context (trying to explicitly force a 3.2 core profile with this GPU via GLFW here fails the window creation but that's an entirely different issue...) For what it's worth, here's the relevant routine excerpted from the render loop, in Golang: func (me *TMesh) render () { curMesh = me curTechnique.OnRenderMesh() gl.BindBuffer(gl.ARRAY_BUFFER, me.glVertBuf) if me.glElemBuf > 0 { gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, me.glElemBuf) gl.VertexAttribPointer(curProg.AttrLocs["aPos"], 3, gl.FLOAT, gl.FALSE, 0, gl.Pointer(nil)) gl.DrawElements(me.glMode, me.glNumIndices, gl.UNSIGNED_INT, gl.Pointer(nil)) gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0) } else { gl.VertexAttribPointer(curProg.AttrLocs["aPos"], 3, gl.FLOAT, gl.FALSE, 0, gl.Pointer(nil)) /* BOOM! */ gl.DrawArrays(me.glMode, 0, me.glNumVerts) } gl.BindBuffer(gl.ARRAY_BUFFER, 0) } So of course this is part of a bigger render-loop, though the whole "*TMesh" construction for now is just two instances, one a simple cube and the other a simple pyramid. What matters is that the entire drawing loop works flawlessly with no errors reported when GL is queried for errors under both 3.3 and 4.2, yet on 3 nvidia GPUs with an explicit 3.2 core profile fails with an error code that according to spec is only invoked in two specific situations, none of which as far as I can tell apply here. What could be wrong here? Have you ever run into this? Any ideas what I have been missing?

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  • Does WCF make the consumption of Restful web services trivial?

    - by Steve Weet
    I have an ASP.net application that currently consumes SOAP web services. This platform is targeted at .net 2.0 and I use Visual Studio Professional 2005 to maintain it. I now have a requirement to consume a number of restful web service within the same application. Is the consumption of Restful web services with WCF so trivial, compared to using HttpClient that it is worth the cost and time of upgrading to Visual Studio 2008 and .Net 3.5 framework

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  • Silverlight 4 Training Kit

    - by ScottGu
    We recently released a new free Silverlight 4 Training Kit that walks you through building business applications with Silverlight 4.  You can browse the training kit online or alternatively download an entire offline version of the training kit.  The training material is structured on teaching how to use the new Silverlight 4 features to build an end to end business application. The training kit includes 8 modules, 25 videos, and several hands on labs. Below is a breakdown and links to all of the content. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Module 1: Introduction Click here to watch this module. In this video John Papa and Ian Griffiths discuss the key areas that the Building Business Applications with Silverlight 4 course focuses on. This module is the overview of the course and covers many key scenarios that are faced when building business applications, and how Silverlight can help address them. Module 2: WCF RIA Services Click here to explore this module. In this lab, you will create a web site for managing conferences that will be the basis for the other labs in this course. Don’t worry if you don’t complete a particular lab in the series – all lab manual instructions are accompanied by completed solutions, so you can either build your own solution from start to finish, or dive straight in at any point using the solutions provided as a starting point. In this lab you will learn how to set up WCF RIA Services, create bindings to the domain context, filter using the domain data source, and create domain service queries. Online Link Download Source Download Lab Document Videos Module 2.1 - WCF RIA Services Ian Griffiths sets up the Entity Framework and WCF RIA Services for the sample Event Manager application for the course. He covers how to set up the services, how the Domain Services work and the role that the DomainContext plays in the sample application. He also reviews the metadata classes and integrating the navigation framework. Module 2.2 – Using WCF RIA Services to Edit Entities Ian Griffiths discusses how he adds the ability to edit and create individual entities with the features built into WCF RIA Services into the sample Event Manager application. He covers data binding fundamentals, IQueryable, LINQ, the DomainDataSource, navigation to a single entity using the navigation framework, and how to use the Visual Studio designer to do much of the work . Module 2.3 – Showing Master/Details Records Using WCF RIA Services Ian Griffiths reviews how to display master/detail records for the sample Event Manager application using WCF RIA Services. He covers how to use the Include attribute to indicate which elements to serialize back to the client. Ian also demonstrates how to use the Data Sources window in the designer to add and bind controls to specific data elements. He wraps up by showing how to create custom services to the Domain Services. Module 3 – Authentication, Validation, MVVM, Commands, Implicit Styles and RichTextBox Click here to visit this module. This lab demonstrates how to build a login screen, integrate ASP.NET authentication, and perform validation on data elements. Model-View-ViewModel (MVVM) is introduced and used in this lab as a pattern to help separate the UI and business logic. You will also learn how to use implicit styling and the new RichTextBox control. Online Link Download Source Download Lab Document Videos Module 3.1 – Authentication Ian Griffiths covers how to integrate a login screen and authentication into the sample Event Manager application. Ian shows how to use the ASP.NET authentication and integrate it into WCF RIA Services and the Silverlight presentation layer. Module 3.2 – MVVM Ian Griffiths covers how to Model-View-ViewModel (MVVM) patterns into the sample Event Manager application. He discusses why MVVM exists, what separated presentation means, and why it is important. He shows how to connect the View to the ViewModel, why data binding is important in this symbiosis, and how everything fits together in the overall application. Module 3.3 –Validation Ian Griffiths discusses how validation of user input can be integrated into the sample Event Manager application. He demonstrates how to use the DataAnnotations, the INotifyDataErrorInfo interface, binding markup extensions, and WCF RIA Services in concert to achieve great validation in the sample application. He discusses how this technique allows for property level validation, entity level validation, and asynchronous server side validation. Module 3.4 – Implicit Styles Ian Griffiths discusses how why implicit styles are important and how they can be integrated into the sample Event Manager application. He shows how implicit styles defined in a resource dictionary can be applied to all elements of a particular kind throughout the application. Module 3.5 – RichTextBox Ian Griffiths discusses how the new RichTextBox control and it can be integrated into the sample Event Manager application. He demonstrates how the RichTextBox can provide editing for the event information and how it can display the rich text for selection and copying. Module 4 – User Profiles, Drop Targets, Webcam and Clipboard Click here to visit this module. This lab builds new features into the sample application to take the user's photo. It teaches you how to use the webcam to capture an image, use Silverlight as a drop target, and take advantage of programmatic access to the clipboard. Link Download Source Download Lab Document Videos Module 4.1 – Webcam Ian Griffiths demonstrates how the webcam adds value to the sample Event Manager application by capturing an image of the attendee. He discusses the VideoCaptureDevice, the CaptureDviceConfiguration, and the CaptureSource classes and how they allow audio and video to be captured so you can grab an image from the capture device and save it. Module 4.2 - Drag and Drop in Silverlight Ian Griffiths demonstrates how to capture and handle the Drop in the sample Event Manager application so the user can drag a photo from a file and drop it into the application. Ian reviews the AllowDrop property, the Drop event, how to access the file that can be dropped, and the other drag related events. He also reviews how to make this work across browsers and the challenges for this. Module 5 – Schedule Planner and Right Mouse Click Click here to visit this module. This lab builds on the application to allow grouping in the DataGrid and implement right mouse click features to add context menu support. Link Download Source Download Lab Document Videos Module 5.1 – Grouping and Binding Ian Griffiths demonstrates how to use the grouping features for data binding in the DataGrid and how it applies to the sample Event Manager application. He reviews the role of the CollectionViewSource in grouping, customizing the templates for headers, and how to work with grouping with ItemsControls. Module 5.2 – Layout Visual States Ian Griffiths demonstrates how to use the Fluid UI animation support for visual states in the ListBox control DataGrid and how it applies to the sample Event Manager application. He reviews the 3 visual states of BeforeLoaded, AfterLoaded, and BeforeUnloaded. Module 5.3 – Right Mouse Click Ian Griffiths demonstrates how to add support for handling the right mouse button click event to display a context menu for the Event Manager application. He demonstrates how to handle the event, show a custom context menu control, and integrate it into the scheduling portion of the application. Module 6 – Printing the Schedule Click here to visit this module. This lab teaches how to use the new printing features in Silverlight 4. The lab walks through the PrintDocument class and the ViewBox control, while showing how to print multiple pages of content using them. Link Download Source Download Lab Document Videos Module 6.1 – Printing and the Viewbox Ian Griffiths demonstrates how to add the ability to print the schedule to the sample Event Manager application. He walks through the importance of the PrintDocument class and its members. He also shows how to handle printing the visual tree and how the ViewBox control can help. Module 6.2 – Multi Page Printing Ian Griffiths expands on his printing discussion by showing how to handle printing multiple pages of content for the sample Event Manager application. He shows how to paginate the content and points out various tips to keep in mind when determining the printable area. Module 7 – Running the Event Dashboard Out of Browser Click here to visit this module. This lab builds a dashboard for the sample application while explaining the fundamentals of the out of browser features, how to handle authentication, displaying notifications (toasts), and how to use native integration to use COM Interop with Silverlight. Link Download Source Download Lab Document Videos Module 7.1 – Out of Browser Ian Griffiths discusses the role of an Out of Browser application for administrators to manage the events and users in the sample Event Manager application. He discusses several reasons why out of browser applications may better suit your needs including custom chrome, toasts, window placement, cross domain access, and file access. He demonstrates the basic technique to take your application and make it work out of browser using the tools. Module 7.2 – NotificationWindow (Toasts) for Elevated Trust Out of Browser Applications Ian Griffiths discusses the how toasts can be used in the sample Event Manager application to show information that may require the user's attention. Ian covers how to create a toast using the NotificationWindow, security implications, and how to make the toast appear as needed. Module 7.3 – Out of Browser Window Placement Ian Griffiths discusses the how to manage the window positioning when building an out of browser application, handling the windows state, and controlling and handling activation of the window. Module 7.4 – Out of Browser Elevated Trust Application Overview Ian Griffiths discusses the implications of creating trusted out of browser application for the Event Manager sample application. He reviews why you might want to use elevated trust, what features is opens to you, and how to take advantage of them. Topics Ian covers include the dynamic keyword in C# 4, the AutomationFactory class, the API to check if you are in a trusted application, and communicating with Excel. Module 8 – Advanced Out of Browser and MEF Click here to visit this module. This hands-on lab walks through the creation of a trusted out of browser application and the new functionality that comes with that. You will learn to use COM Automation, handle the window closing event, set custom window chrome, digitally sign your Silverlight out of browser trusted application, create a silent install option, and take advantage of MEF. Link Download Source Download Lab Document Videos Module 8.1 – Custom Window Chrome for Elevated Trust Out of Browser Applications Ian Griffiths discusses how to replace the standard operating system window chrome with customized chrome for an elevated trusted out of browser application. He covers how it is important to handle close, resize, minimize, and maximize events. Ian mentions that the tooling was not ready when he shot this video, but the good news is that the tooling now supports setting the custom chrome directly from the property page for the Silverlight application. Module 8.2 – Window Closing Event for Out of Browser Applications Ian Griffiths discusses the WindowClosing event and how to handle and optionally cancel the event. Module 8.3 – Silent Install of Out of Browser Applications Ian Griffiths discusses how to use the SLLauncher executable to install an out of browser application. He discusses the optional command line switches that can be set including how the emulate switch can help you emulate the install process. Ian also shows how to setup a shortcut for the application and tell the application where it should look for future updates online. Module 8.4 – Digitally Signing Out of Browser Application Ian Griffiths discusses how and why to digitally sign an out of browser application using the signtool program. He covers what trusted certificates are, the implications of signing (or not signing), and the effect on the user experience. Module 8.5 – The Value of MEF with Silverlight Ian Griffiths discusses what MEF is, how your application can benefit from it, and the fundamental features it puts at your disposal. He covers the 3 step import, export and compose process as well as how to dynamically import XAP files using MEF. Summary As you can probably tell from the long list above – this series contains a ton of great content, and hopefully provides a nice end-to-end walkthrough that helps explain how to take advantage of Silverlight 4 (and all its new features).  Hope this helps, Scott

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  • Imperative vs. LINQ Performance on WP7

    - by Bil Simser
    Jesse Liberty had a nice post presenting the concepts around imperative, LINQ and fluent programming to populate a listbox. Check out the post as it’s a great example of some foundational things every .NET programmer should know. I was more interested in what the IL code that would be generated from imperative vs. LINQ was like and what the performance numbers are and how they differ. The code at the instruction level is interesting but not surprising. The imperative example with it’s creating lists and loops weighs in at about 60 instructions. .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } 1: .method private hidebysig instance void ImperativeMethod() cil managed 2: { 3: .maxstack 3 4: .locals init ( 5: [0] class [mscorlib]System.Collections.Generic.IEnumerable`1<int32> someData, 6: [1] class [mscorlib]System.Collections.Generic.List`1<int32> inLoop, 7: [2] int32 n, 8: [3] class [mscorlib]System.Collections.Generic.IEnumerator`1<int32> CS$5$0000, 9: [4] bool CS$4$0001) 10: L_0000: nop 11: L_0001: ldc.i4.1 12: L_0002: ldc.i4.s 50 13: L_0004: call class [mscorlib]System.Collections.Generic.IEnumerable`1<int32> [System.Core]System.Linq.Enumerable::Range(int32, int32) 14: L_0009: stloc.0 15: L_000a: newobj instance void [mscorlib]System.Collections.Generic.List`1<int32>::.ctor() 16: L_000f: stloc.1 17: L_0010: nop 18: L_0011: ldloc.0 19: L_0012: callvirt instance class [mscorlib]System.Collections.Generic.IEnumerator`1<!0> [mscorlib]System.Collections.Generic.IEnumerable`1<int32>::GetEnumerator() 20: L_0017: stloc.3 21: L_0018: br.s L_003a 22: L_001a: ldloc.3 23: L_001b: callvirt instance !0 [mscorlib]System.Collections.Generic.IEnumerator`1<int32>::get_Current() 24: L_0020: stloc.2 25: L_0021: nop 26: L_0022: ldloc.2 27: L_0023: ldc.i4.5 28: L_0024: cgt 29: L_0026: ldc.i4.0 30: L_0027: ceq 31: L_0029: stloc.s CS$4$0001 32: L_002b: ldloc.s CS$4$0001 33: L_002d: brtrue.s L_0039 34: L_002f: ldloc.1 35: L_0030: ldloc.2 36: L_0031: ldloc.2 37: L_0032: mul 38: L_0033: callvirt instance void [mscorlib]System.Collections.Generic.List`1<int32>::Add(!0) 39: L_0038: nop 40: L_0039: nop 41: L_003a: ldloc.3 42: L_003b: callvirt instance bool [mscorlib]System.Collections.IEnumerator::MoveNext() 43: L_0040: stloc.s CS$4$0001 44: L_0042: ldloc.s CS$4$0001 45: L_0044: brtrue.s L_001a 46: L_0046: leave.s L_005a 47: L_0048: ldloc.3 48: L_0049: ldnull 49: L_004a: ceq 50: L_004c: stloc.s CS$4$0001 51: L_004e: ldloc.s CS$4$0001 52: L_0050: brtrue.s L_0059 53: L_0052: ldloc.3 54: L_0053: callvirt instance void [mscorlib]System.IDisposable::Dispose() 55: L_0058: nop 56: L_0059: endfinally 57: L_005a: nop 58: L_005b: ldarg.0 59: L_005c: ldfld class [System.Windows]System.Windows.Controls.ListBox PerfTest.MainPage::LB1 60: L_0061: ldloc.1 61: L_0062: callvirt instance void [System.Windows]System.Windows.Controls.ItemsControl::set_ItemsSource(class [mscorlib]System.Collections.IEnumerable) 62: L_0067: nop 63: L_0068: ret 64: .try L_0018 to L_0048 finally handler L_0048 to L_005a 65: } 66:   67: Compare that to the IL generated for the LINQ version which has about half of the instructions and just gets the job done, no fluff. .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } 1: .method private hidebysig instance void LINQMethod() cil managed 2: { 3: .maxstack 4 4: .locals init ( 5: [0] class [mscorlib]System.Collections.Generic.IEnumerable`1<int32> someData, 6: [1] class [mscorlib]System.Collections.Generic.IEnumerable`1<int32> queryResult) 7: L_0000: nop 8: L_0001: ldc.i4.1 9: L_0002: ldc.i4.s 50 10: L_0004: call class [mscorlib]System.Collections.Generic.IEnumerable`1<int32> [System.Core]System.Linq.Enumerable::Range(int32, int32) 11: L_0009: stloc.0 12: L_000a: ldloc.0 13: L_000b: ldsfld class [System.Core]System.Func`2<int32, bool> PerfTest.MainPage::CS$<>9__CachedAnonymousMethodDelegate6 14: L_0010: brtrue.s L_0025 15: L_0012: ldnull 16: L_0013: ldftn bool PerfTest.MainPage::<LINQProgramming>b__4(int32) 17: L_0019: newobj instance void [System.Core]System.Func`2<int32, bool>::.ctor(object, native int) 18: L_001e: stsfld class [System.Core]System.Func`2<int32, bool> PerfTest.MainPage::CS$<>9__CachedAnonymousMethodDelegate6 19: L_0023: br.s L_0025 20: L_0025: ldsfld class [System.Core]System.Func`2<int32, bool> PerfTest.MainPage::CS$<>9__CachedAnonymousMethodDelegate6 21: L_002a: call class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0> [System.Core]System.Linq.Enumerable::Where<int32>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>, class [System.Core]System.Func`2<!!0, bool>) 22: L_002f: ldsfld class [System.Core]System.Func`2<int32, int32> PerfTest.MainPage::CS$<>9__CachedAnonymousMethodDelegate7 23: L_0034: brtrue.s L_0049 24: L_0036: ldnull 25: L_0037: ldftn int32 PerfTest.MainPage::<LINQProgramming>b__5(int32) 26: L_003d: newobj instance void [System.Core]System.Func`2<int32, int32>::.ctor(object, native int) 27: L_0042: stsfld class [System.Core]System.Func`2<int32, int32> PerfTest.MainPage::CS$<>9__CachedAnonymousMethodDelegate7 28: L_0047: br.s L_0049 29: L_0049: ldsfld class [System.Core]System.Func`2<int32, int32> PerfTest.MainPage::CS$<>9__CachedAnonymousMethodDelegate7 30: L_004e: call class [mscorlib]System.Collections.Generic.IEnumerable`1<!!1> [System.Core]System.Linq.Enumerable::Select<int32, int32>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>, class [System.Core]System.Func`2<!!0, !!1>) 31: L_0053: stloc.1 32: L_0054: ldarg.0 33: L_0055: ldfld class [System.Windows]System.Windows.Controls.ListBox PerfTest.MainPage::LB2 34: L_005a: ldloc.1 35: L_005b: callvirt instance void [System.Windows]System.Windows.Controls.ItemsControl::set_ItemsSource(class [mscorlib]System.Collections.IEnumerable) 36: L_0060: nop 37: L_0061: ret 38: } Again, not surprising here but a good indicator that you should consider using LINQ where possible. In fact if you have ReSharper installed you’ll see a squiggly (technical term) in the imperative code that says “Hey Dude, I can convert this to LINQ if you want to be c00L!” (or something like that, it’s the 2010 geek version of Clippy). What about the fluent version? As Jon correctly pointed out in the comments, when you compare the IL for the LINQ code and the IL for the fluent code it’s the same. LINQ and the fluent interface are just syntactical sugar so you decide what you’re most comfortable with. At the end of the day they’re both the same. Now onto the numbers. Again I expected the imperative version to be better performing than the LINQ version (before I saw the IL that was generated). Call it womanly instinct. A gut feel. Whatever. Some of the numbers are interesting though. For Jesse’s example of 50 items, the numbers were interesting. The imperative sample clocked in at 7ms while the LINQ version completed in 4. As the number of items went up, the elapsed time didn’t necessarily climb exponentially. At 500 items they were pretty much the same and the results were similar up to about 50,000 items. After that I tried 500,000 items where the gap widened but not by much (2.2 seconds for imperative, 2.3 for LINQ). It wasn’t until I tried 5,000,000 items where things were noticeable. Imperative filled the list in 20 seconds while LINQ took 8 seconds longer (although personally I wouldn’t suggest you put 5 million items in a list unless you want your users showing up at your door with torches and pitchforks). Here’s the table with the full results. Method/Items 50 500 5,000 50,000 500,000 5,000,000 Imperative 7ms 7ms 38ms 223ms 2230ms 20974ms LINQ/Fluent 4ms 6ms 41ms 240ms 2310ms 28731ms Like I said, at the end of the day it’s not a huge difference and you really don’t want your users waiting around for 30 seconds on a mobile device filling lists. In fact if Windows Phone 7 detects you’re taking more than 10 seconds to do any one thing, it considers the app hung and shuts it down. The results here are for Windows Phone 7 but frankly they're the same for desktop and web apps so feel free to apply it generally. From a programming perspective, choose what you like. Some LINQ statements can get pretty hairy so I usually fall back with my simple mind and write it imperatively. If you really want to impress your friends, write it old school then let ReSharper do the hard work for! Happy programming!

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  • Business Forces: SOA Adoption

    The only constant in today’s business environment is change. Businesses that continuously foresee change and adapt quickly will gain market share and increased growth. In our ever growing global business environment change is driven by data in regards to collecting, maintaining, verifying and distributing data.  Companies today are made and broken over data. Would anyone still use Google if they did not have one of the most accurate search indexes on the internet? No, because their value is in their data and the quality of their data. Due to the increasing focus on data, companies have been adopting new methodologies for gaining more control over their data while attempting to reduce the costs of maintaining it. In addition, companies are also trying to reduce the time it takes to analyze data in regards to various market forces to foresee changes prior to them actually occurring.   Benefits of Adopting SOA Services can be maintained separately from other services and applications so that a change in one service will only affect itself and client services or applications. The advent of services allows for system functionality to be distributed across a network or multiple networks. The costs associated with maintain business functionality is much higher in standard application development over SOA due to the fact that one Services can be maintained and shared to other applications instead of multiple instances of business functionality being duplicated via hard coding in to several applications. When multiple applications use a single service for a specific business function then the all of the data being processed will be consistent in terms of quality and accuracy through the applications. Disadvantages of Adopting SOA Increased initial costs and timelines are associated with SOA due to the fact that services need to be created as well as applications need to be modified to call the services In order for an SOA project to be successful the project must obtain company and management support in order to gain the proper exposure, funding, and attention. If SOA is new to a company they must also support the proper training in order for the project to be designed, and implemented correctly. References: Tews, R. (2007). Beyond IT: Exploring the Business Value of SOA. SOA Magazine Issue XI.

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