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• Why should you choose Oracle WebLogic 12c instead of JBoss EAP 6?

  - by Ricardo Ferreira

  In this post, I will cover some technical differences between Oracle WebLogic 12c and JBoss EAP 6, which was released a couple days ago from Red Hat. This article claims to help you in the evaluation of key points that you should consider when choosing for an Java EE application server. In the following sections, I will present to you some important aspects that most customers ask us when they are seriously evaluating for an middleware infrastructure, specially if you are considering JBoss for some reason. I would suggest that you keep the following question in mind while you are reading the points: "Why should I choose JBoss instead of WebLogic?" 1) Multi Datacenter Deployment and Clustering - D/R ("Disaster & Recovery") architecture support is embedded on the WebLogic Server 12c product. JBoss EAP 6 on the other hand has no direct D/R support included, Red Hat relies on third-part tools with higher prices. When you consider a middleware solution to host your business critical application, you should worry with every architectural aspect that are related with the solution. Fail-over support is one little aspect of a truly reliable solution. If you do not worry about D/R, your solution will not be reliable. Having said that, with Red Hat and JBoss EAP 6, you have this extra cost that will increase considerably the total cost of ownership of the solution. As we commonly hear from analysts, open-source are not so cheaper when you start seeing the big picture. - WebLogic Server 12c supports advanced LAN clustering, detection of death servers and have a common alert framework. JBoss EAP 6 on the other hand has limited LAN clustering support with no server death detection. They do not generate any alerts when servers goes down (only if you buy JBoss ON which is a separated technology, but until now does not support JBoss EAP 6) and manual intervention are required when servers goes down. In most cases, admin people must rely on "kill -9", "tail -f someFile.log" and "ps ax | grep java" commands to manage failures and clustering anomalies. - WebLogic Server 12c supports the concept of Node Manager, which is a separated process that runs on the physical | virtual servers that allows extend the administration of the cluster to WebLogic managed servers that are often distributed across multiple machines and geographic locations. JBoss EAP 6 on the other hand has no equivalent technology. Whole server instances must be managed individually. - WebLogic Server 12c Node Manager supports Coherence to boost performance when managing servers. JBoss EAP 6 on the other hand has no similar technology. There is no way to coordinate JBoss and infiniband instances provided by JBoss using high throughput and low latency protocols like InfiniBand. The Node Manager feature also allows another very important feature that JBoss EAP lacks: secure the administration. When using WebLogic Node Manager, all the administration tasks are sent to the managed servers in a secure tunel protected by a certificate, which means that the transport layer that separates the WebLogic administration console from the managed servers are secured by SSL. - WebLogic Server 12c are now integrated with OTD ("Oracle Traffic Director") which is a web server technology derived from the former Sun iPlanet Web Server. This software complements the web server support offered by OHS ("Oracle HTTP Server"). Using OTD, WebLogic instances are load-balanced by a high powerful software that knows how to handle SDP ("Socket Direct Protocol") over InfiniBand, which boost performance when used with engineered systems technologies like Oracle Exalogic Elastic Cloud. JBoss EAP 6 on the other hand only offers support to Apache Web Server with custom modules created to deal with JBoss clusters, but only across standard TCP/IP networks.  2) Application and Runtime Diagnostics - WebLogic Server 12c have diagnostics capabilities embedded on the server called WLDF ("WebLogic Diagnostic Framework") so there is no need to rely on third-part tools. JBoss EAP 6 on the other hand has no diagnostics capabilities. Their only diagnostics tool is the log generated by the application server. Admin people are encouraged to analyse thousands of log lines to find out what is going on. - WebLogic Server 12c complement WLDF with JRockit MC ("Mission Control"), which provides to administrators and developers a complete insight about the JVM performance, behavior and possible bottlenecks. WebLogic Server 12c also have an classloader analysis tool embedded, and even a log analyzer tool that enables administrators and developers to view logs of multiple servers at the same time. JBoss EAP 6 on the other hand relies on third-part tools to do something similar. Again, only log searching are offered to find out whats going on. - WebLogic Server 12c offers end-to-end traceability and monitoring available through Oracle EM ("Enterprise Manager"), including monitoring of business transactions that flows through web servers, ESBs, application servers and database servers, all of this with high deep JVM analysis and diagnostics. JBoss EAP 6 on the other hand, even using JBoss ON ("Operations Network"), which is a separated technology, does not support those features. Red Hat relies on third-part tools to provide direct Oracle database traceability across JVMs. One of those tools are Oracle EM for non-Oracle middleware that manage JBoss, Tomcat, Websphere and IIS transparently. - WebLogic Server 12c with their JRockit support offers a tool called JRockit Flight Recorder, which can give developers a complete visibility of a certain period of application production monitoring with zero extra overhead. This automatic recording allows you to deep analyse threads latency, memory leaks, thread contention, resource utilization, stack overflow damages and GC ("Garbage Collection") cycles, to observe in real time stop-the-world phenomenons, generational, reference count and parallel collects and mutator threads analysis. JBoss EAP 6 don't even dream to support something similar, even because they don't have their own JVM. 3) Application Server Administration - WebLogic Server 12c offers a complete administration console complemented with scripting and macro-like recording capabilities. A single WebLogic console can managed up to hundreds of WebLogic servers belonging to the same domain. JBoss EAP 6 on the other hand has a limited console and provides a XML centric administration. JBoss, after ten years, started the development of a rudimentary centralized administration that still leave a lot of administration tasks aside, so admin people and developers must touch scripts and XML configuration files for most advanced and even simple administration tasks. This lead applications to error prone and risky deployments. Even using JBoss ON, JBoss EAP are not able to offer decent administration features for admin people which must be high skilled in JBoss internal architecture and its managing capabilities. - Oracle EM is available to manage multiple domains, databases, application servers, operating systems and virtualization, with a complete end-to-end visibility. JBoss ON does not provide management capabilities across the complete architecture, only basic monitoring. Even deployment must be done aside JBoss ON which does no integrate well with others softwares than JBoss. Until now, JBoss ON does not supports JBoss EAP 6, so even their minimal support for JBoss are not available for JBoss EAP 6 leaving customers uncovered and subject to high skilled JBoss admin people. - WebLogic Server 12c has the same administration model whatever is the topology selected by the customer. JBoss EAP 6 on the other hand differentiates between two operational models: standalone-mode and domain-mode, that are not consistent with each other. Depending on the mode used, the administration skill is different. - WebLogic Server 12c has no point-of-failures processes, and it does not need to define any specialized server. Domain model in WebLogic is available for years (at least ten years or more) and is production proven. JBoss EAP 6 on the other hand needs special processes to garantee JBoss integrity, the PC ("Process-Controller") and the HC ("Host-Controller"). Different from WebLogic, the domain model in JBoss is quite new (one year at tops) of maturity, and need to mature considerably until start doing things like WebLogic domain model does. - WebLogic Server 12c supports parallel deployment model which enables some artifacts being deployed at the same time. JBoss EAP 6 on the other hand does not have any similar feature. Every deployment are done atomically in the containers. This means that if you have a huge EAR (an EAR of 120 MB of size for instance) and deploy onto JBoss EAP 6, this EAR will take some minutes in order to starting accept thread requests. The same EAR deployed onto WebLogic Server 12c will reduce the deployment time at least in 2X compared to JBoss. 4) Support and Upgrades - WebLogic Server 12c has patch management available. JBoss EAP 6 on the other hand has no patch management available, each JBoss EAP instance should be patched manually. To achieve such feature, you need to buy a separated technology called JBoss ON ("Operations Network") that manage this type of stuff. But until now, JBoss ON does not support JBoss EAP 6 so, in practice, JBoss EAP 6 does not have this feature. - WebLogic Server 12c supports previuous WebLogic domains without any reconfiguration since its kernel is robust and mature since its creation in 1995. JBoss EAP 6 on the other hand has a proven lack of supportability between JBoss AS 4, 5, 6 and 7. Different kernels and messaging engines were implemented in JBoss stack in the last five years reveling their incapacity to create a well architected and proven middleware technology. - WebLogic Server 12c has patch prescription based on customer configuration. JBoss EAP 6 on the other hand has no such capability. People need to create ticket supports and have their installations revised by Red Hat support guys to gain some patch prescription from them. - Oracle WebLogic Server independent of the version has 8 years of support of new patches and has lifetime release of existing patches beyond that. JBoss EAP 6 on the other hand provides patches for a specific application server version up to 5 years after the release date. JBoss EAP 4 and previous versions had only 4 years. A good question that Red Hat will argue to answer is: "what happens when you find issues after year 5"?  5) RAC ("Real Application Clusters") Support - WebLogic Server 12c ships with a specific JDBC driver to leverage Oracle RAC clustering capabilities (Fast-Application-Notification, Transaction Affinity, Fast-Connection-Failover, etc). Oracle JDBC thin driver are also available. JBoss EAP 6 on the other hand ships only the standard Oracle JDBC thin driver. Load balancing with Oracle RAC are not supported. Manual intervention in case of planned or unplanned RAC downtime are necessary. In JBoss EAP 6, situation does not reestablish automatically after downtime. - WebLogic Server 12c has a feature called Active GridLink for Oracle RAC which provides up to 3X performance on OLTP applications. This seamless integration between WebLogic and Oracle database enable more value added to critical business applications leveraging their investments in Oracle database technology and Oracle middleware. JBoss EAP 6 on the other hand has no performance gains at all, even when admin people implement some kind of connection-pooling tuning. - WebLogic Server 12c also supports transaction and web session affinity to the Oracle RAC, which provides aditional gains of performance. This is particularly interesting if you are creating a reliable solution that are distributed not only in an LAN cluster, but into a different data center. JBoss EAP 6 on the other hand has no such support. 6) Standards and Technology Support - WebLogic Server 12c is fully Java EE 6 compatible and production ready since december of 2011. JBoss EAP 6 on the other hand became fully compatible with Java EE 6 only in the community version after three months, and production ready only in a few days considering that this article was written in June of 2012. Red Hat says that they are the masters of innovation and technology proliferation, but compared with Oracle and even other proprietary vendors like IBM, they historically speaking are lazy to deliver the most newest technologies and standards adherence. - Oracle is the steward of Java, driving innovation into the platform from commercial and open-source vendors. Red Hat on the other hand does not have its own JVM and relies on third-part JVMs to complete their application server offer. 95% of Red Hat customers are using Oracle HotSpot as JVM, which means that without Oracle involvement, their support are limited exclusively to the application server layer and we all know that most problems are happens in the JVM layer. - WebLogic Server 12c supports natively JDK 7, which empower developers to explore the maximum of the Java platform productivity when writing code. This feature differentiate WebLogic from others application servers (except GlassFish that are also managed by Oracle) because the usage of JDK 7 introduce such remarkable productivity features like the "try-with-resources" enhancement, catching multiple exceptions with one try block, Strings in the switch statements, JVM improvements in terms of JDBC, I/O, networking, security, concurrency and of course, the most important feature of Java 7: native support for multiple non-Java languages. More features regarding JDK 7 can be found here. JBoss EAP 6 on the other hand does not support JDK 7 officially, they comment in their community version that "Java SE 7 can be used with JBoss 7" which does not gives you any guarantees of enterprise support for JDK 7. - Oracle WebLogic Server 12c supports integration with Spring framework allowing Spring applications to use WebLogic special transaction manager, exposing bean interfaces to WebLogic MBeans to take advantage of all WebLogic monitoring and administration advantages. JBoss EAP 6 on the other hand has no special integration with Spring. In fact, Red Hat offers a suspicious package called "JBoss Web Platform" that in theory supports Spring, but in practice this package does not offers any special integration. It is just a facility for Red Hat customers to have support from both JBoss and Spring technology using the same customer support. 7) Lightweight Development - Oracle WebLogic Server 12c and Oracle GlassFish are completely integrated and can share applications without any modifications. Starting with the 12c version, WebLogic now understands natively GlassFish deployment descriptors and specific configurations in order to offer you a truly and reliable migration path from a community Java EE application server to a enterprise middleware product like WebLogic. JBoss EAP 6 on the other hand has no support to natively reuse an existing (or still in development) application from JBoss AS community server. Users of JBoss suffer of critical issues during deployment time that includes: changing the libraries and dependencies of the application, patching the DTD or XSD deployment descriptors, refactoring of the application layers due classloading issues and anomalies, rebuilding of persistence, business and web layers due issues with "usage of the certified version of an certain dependency" or "frameworks that Red Hat potentially does not recommend" etc. If you have the culture or enterprise IT directive of developing Java EE applications using community middleware to in a certain future, transition to enterprise (supported by a vendor) middleware, Oracle WebLogic plus Oracle GlassFish offers you a more sustainable solution. - WebLogic Server 12c has a very light ZIP distribution (less than 165 MB). JBoss EAP 6 ZIP size is around 130 MB, together with JBoss ON you have more 100 MB resulting in a higher download footprint. This is particularly interesting if you plan to use automated setup of application server instances (for example, to rapidly setup a development or staging environment) using Maven or Hudson. - WebLogic Server 12c has a complete integration with Maven allowing developers to setup WebLogic domains with few commands. Tasks like downloading WebLogic, installation, domain creation, data sources deployment are completely integrated. JBoss EAP 6 on the other hand has a limited offer integration with those tools.  - WebLogic Server 12c has a startup mode called WLX that turns-off EJB, JMS and JCA containers leaving enabled only the web container with Java EE 6 web profile. JBoss EAP 6 on the other hand has no such feature, you need to disable manually the containers that you do not want to use. - WebLogic Server 12c supports fastswap, which enables you to change classes without redeployment. This is particularly interesting if you are developing patches for the application that is already deployed and you do not want to redeploy the entire application. This is the same behavior that most application servers offers to JSP pages, but with WebLogic Server 12c, you have the same feature for Java classes in general. JBoss EAP 6 on the other hand has no such support. Even JBoss EAP 5 does not support this until now. 8) JMS and Messaging - WebLogic Server 12c has a proven and high scalable JMS implementation since its initial release in 1995. JBoss EAP 6 on the other hand has a still immature technology called HornetQ, which was introduced in JBoss EAP 5 replacing everything that was implemented in the previous versions. Red Hat loves to introduce new technologies across JBoss versions, playing around with customers and their investments. And when they are asked about why they have changed the implementation and caused such a mess, their answer is always: "the previous implementation was inadequate and not aligned with the community strategy so we are creating a new a improved one". This Red Hat practice leads to uncomfortable investments that in a near future (sometimes less than a year) will be affected in someway. - WebLogic Server 12c has troubleshooting and monitoring features included on the WebLogic console and WLDF. JBoss EAP 6 on the other hand has no direct monitoring on the console, activity is reflected only on the logs, no debug logs available in case of JMS issues. - WebLogic Server 12c has extremely good performance and scalability. JBoss EAP 6 on the other hand has a JMS storage mechanism relying on Oracle database or MySQL. This means that if an issue in production happens and Red Hat affirms that an performance issue is happening due to database problems, they will not support you on the performance issue. They will orient you to call Oracle instead. - WebLogic Server 12c supports messaging enterprise features like SAF ("Store and Forward"), Distributed Queues/Topics and Foreign JMS providers support that leverage JMS implementations without compromise developer code making things completely transparent. JBoss EAP 6 on the other hand do not even dream to support such features. 9) Caching and Grid - Coherence, which is the leading and most mature data grid technology from Oracle, is available since early 2000 and was integrated with WebLogic in 2009. Coherence and WebLogic clusters can be both managed from WebLogic administrative console. Even Node Manager supports Coherence. JBoss on the other hand discontinued JBoss Cache, which was their caching implementation just like they did with the messaging implementation (JBossMQ) which was a issue for long term customers. JBoss EAP 6 ships InfiniSpan version 1.0 which is immature and lack a proven record of successful cases and reliability. - WebLogic Server 12c has a feature called ActiveCache which uses Coherence to, without any code changes, replicate HTTP sessions from both WebLogic and other application servers like JBoss, Tomcat, Websphere, GlassFish and even Microsoft IIS. JBoss EAP 6 on the other hand does have such support and even when they do in the future, they probably will support only their own application server. - Coherence can be used to manage both L1 and L2 cache levels, providing support to Oracle TopLink and others JPA compliant implementations, even Hibernate. JBoss EAP 6 and Infinispan on the other hand supports only Hibernate. And most important of all: Infinispan does not have any successful case of L1 or L2 caching level support using Hibernate, which lead us to reflect about its viability. 10) Performance - WebLogic Server 12c is certified with Oracle Exalogic Elastic Cloud and can run unchanged applications at this engineered system. This approach can benefit customers from Exalogic optimization's of both kernel and JVM layers to boost performance in terms of 10X for web, OLTP, JMS and grid applications. JBoss EAP 6 on the other hand has no investment on engineered systems: customers do not have the choice to deploy on a Java ultra fast system if their project becomes relevant and performance issues are detected. - WebLogic Server 12c maintains a performance gain across each new release: starting on WebLogic 5.1, the overall performance gain has been close to 4X, which close to a 20% gain release by release. JBoss on the other hand does not provide SPECJAppServer or SPECJEnterprise performance benchmarks. Their so called "performance gains" remains hidden in their customer environments, which lead us to think if it is true or not since we will never get access to those environments. - WebLogic Server 12c has industry performance benchmarks with submissions across platforms and configurations leading SPECJ. Oracle WebLogic leads SPECJAppServer performance in multiple categories, fitting all customer topologies like: dual-node, single-node, multi-node and multi-node with RAC. JBoss... again, does not provide any SPECJAppServer performance benchmarks. - WebLogic Server 12c has a feature called work manager which allows your application to embrace new performance levels based on critical resource utilization of the CPUs usage. Work managers prioritizes work and allocates threads based on an execution model that takes into account administrator-defined parameters and actual run-time performance and throughput. JBoss EAP 6 on the other hand has no compared feature and probably they never will. Not supporting such feature like work managers, JBoss EAP 6 forces admin people and specially developers to uncover performance gains in a intrusive way, rewriting the code and doing performance refactorings. 11) Professional Services Support - WebLogic Server 12c and any other technology sold by Oracle give customers the possibility of hire OCS ("Oracle Consulting Services") to manage critical scenarios, deployment assistance of new applications, high skilled consultancy of architecture, best practices and people allocation together with customer teams. All OCS services are available without any restrictions, having the customer bought software from Oracle or just starting their implementation before any acquisition. JBoss EAP 6 or Red Hat to be more specifically, only offers professional services if you buy subscriptions from them. If you are developing a new critical application for your business and need the help of Red Hat for a serious issue or architecture decision, they will probably say: "OK... I can help you but after you buy subscriptions from me". Red Hat also does not allows their professional services consultants to manage environments that uses community based software. They will probably force you to first buy a subscription, download their "enterprise" version and them, optionally hire their consultants. - Oracle provides you our university to educate your team into our technologies, including of course specialized trainings of WebLogic application server. At any time and location, you can hire Oracle to train your team so you get trustful knowledge according to your specific needs. Certifications for the products are also available if your technical people desire to differentiate themselves as professionals. Red Hat on the other hand have a limited pool of resources to train your team in their technologies. Basically they are selling training and certification for RHEL ("Red Hat Enterprise Linux") but if you demand more specialized training in JBoss middleware, they will probably connect you to some "certified" partner localized training since they are apparently discontinuing their education center, at least here in Brazil. They were not able to reproduce their success with RHEL education to their middleware division since they need first sell the subscriptions to after gives you specialized training. And again, they only offer you specialized training based on their enterprise version (EAP in the case of JBoss) which means that the courses will be a quite outdated. There are reports of developers that took official training's from Red Hat at this year (2012) and in a certain JBoss advanced course, Red Hat supposedly covered JBossMQ as the messaging subsystem, and even the printed material provided was based on JBossMQ since the training was created for JBoss EAP 4.3. 12) Encouraging Transparency without Ulterior Motives - WebLogic Server 12c like any other software from Oracle can be downloaded any time from anywhere, you should only possess an OTN ("Oracle Technology Network") credential and you can download any enterprise software how many times you want. And is not some kind of "trial" version. It is the official binaries that will be running for ever in your data center. Oracle does not encourages the usage of "specific versions" of our software. The binaries you buy from Oracle are the same binaries anyone in the world could download and use for testing and personal education. JBoss EAP 6 on the other hand are not available for download unless you buy a subscription and get access to the Red Hat enterprise repositories. If you need to test, learn or just start creating your application using Red Hat's middleware software, you should download it from the community website. You are not allowed to download the enterprise version that, according to Red Hat are more secure, reliable and robust. But no one of us want to start the development of a software with an unsecured, unreliable and not scalable middleware right? So what you do? You are "invited" by Red Hat to buy subscriptions from them to get access to the "cool" version of the software. - WebLogic Server 12c prices are publicly available in the Oracle website. If you want to know right now how much WebLogic will cost to your organization, just click here and get access to our price list. In the case of WebLogic, check out the "US Oracle Technology Commercial Price List". Oracle also encourages you to get in touch with a sales representative to discuss discounts that would make possible the investment into our technology. But you are not required to do this, only if you are interested in buying our technology or maybe you want to discuss some discount scenarios. JBoss EAP 6 on the other hand does not have its cost publicly available in Red Hat's website or in any other media, at least is not so easy to get such information. The only link you will possibly find in their website is a "Contact a Sales Representative" link. This is not a very good relationship between an customer and an vendor. This is not an example of transparency, mainly when the software are sold as open. In this situations, customers expects to see the software prices publicly available, so they can have the chance to decide, based on the existing features of the software, if the cost is fair or not. Conclusion Oracle WebLogic is the most mature, secure, reliable and scalable Java EE application server of the market, and have a proven record of success around the globe to prove it's majority. Don't lose the chance to discover today how WebLogic could fit your needs and sustain your global IT middleware strategy, no matter if your strategy are completely based on the Cloud or not.

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• Some New .NET Toys (Repost)

  - by Kevin Grossnicklaus

  Last week I was fortunate enough to spend time in Redmond on Microsoft’s campus for the 2011 Microsoft MVP Summit. It was great to hang out with a number of old friends and get the opportunity to talk tech with the various product teams up at Microsoft. The weather wasn’t exactly sunny but Microsoft always does a great job with the Summit and everyone had a blast (heck, I even got to run the bases at SafeCo field) While much of what we saw is covered under NDA, there a ton of great things in the pipeline from Microsoft and many things that are already available (or just became so) that I wasn’t necessarily aware of. The purpose of this post is to share some of the info I learned on resources and tools available to .NET developers today. Please let me know if you have any questions (or if you know of something else cool which might benefit others). Enjoy! Visual Studio 2010 SP1 Microsoft has issued the RTM release of Visual Studio 2010 SP1. You can download the full SP1 on MSDN as of today (March 10th to the general public) and take advantage of such things as: Silverlight 4 is included in the box (as opposed to a separate install) Silverlight 4 Profiling WCF RIA Services SP1 Intellitrace for 64-bit and SharePoint ASP.NET now easily supports IIS Express and SQL CE Want a description of all that’s new beyond the above biased list (which arguably only contains items I think are important)? Check out this KB article. Portable Library Tools CTP Without much fanfare Microsoft has released a CTP of a new add-in to Visual Studio 2010 which simplifies code sharing between projects targeting different runtimes (i.e. Silverlight, WPF, Win7 Phone, XBox). With this Add-In installed you can add a new project of type “Portable Library” and specify which platforms you wish to target. Once that is done, any code added to this library will be limited to use only features which are common to all selected frameworks. Other projects can now reference this portable library and be provided assemblies custom built to their environment. This greatly simplifies the current process of sharing linked files between platforms like WPF and Silverlight. You can find out more about this CTP and how it works on this great blog post. Visual Studio Async CTP Microsoft has also released a CTP of a set of language and framework enhancements to provide a much more powerful asynchronous programming model. Due to the focus on async programming in all types of platforms (and it being the ONLY option in Silverlight and Win7 phone) a move towards a simpler and more understandable model is always a good thing. This CTP (called Visual Studio Async CTP) can be downloaded here. You can read more about this CTP on this blog post. MSDN Code Samples Gallery Microsoft has also launched new code samples gallery on their MSDN site: http://code.msdn.microsoft.com/. This site allows you to easily search for small samples of code related to a particular technology or platform. If a sample of code you are looking for is not found, you can request one via the site and other developers can see your request and provide a sample to the site to suit your needs. You can also peruse requested samples and, if you find a scenario where you can provide value, upload your own sample for the benefit of others. Samples are packaged into the VS .vsix format and include any necessary references/dependencies. By using .vsix as the deployment mechanism, as samples are installed from the site they are kept in your Visual Studio 2010 Samples Gallery and kept for your future reference. If you get a chance, check out the site and see how it is done. Although a somewhat simple concept, I was very impressed with their implementation and the way they went about trying to suit a need. I’ll definitely be looking there in the future as need something or want to share something. MSDN Search Capabilities Another item I learned recently and was not aware of (that might seem trivial to some) is the power of the MSDN site’s search capabilities. Between the Code Samples Gallery described above and the search enhancements on MSDN, Microsoft is definitely investing in their platform to help provide developers of all skill levels the tools and resources they need to be successful. What do I mean by the MSDN search capability and why should you care? If you go to the MSDN home page (http://msdn.microsoft.com) and use the “Search MSDN with Big” box at the very top of the page you will see some very interesting results. First, the search actually doesn’t just search the MSDN library it searches: MSDN Library All Microsoft Blogs CodePlex StackOverflow Downloads MSDN Magazine Support Knowledgebase (I’m not sure it even ends there but the above are all I know of) Beyond just searching all the above locations, the results are formatted very nicely to give some contextual information based on where the result came from. For example, if a keyword search returned results from CodePlex, each row in the search results screen would include a large amount of information specific to CodePlex such as: Looking at the above results immediately tells you everything from the page views to the CodePlex ratings. All in all, knowing that this much information is indexed and available from a single search location will lead me to utilize this as one of my initial searches for development information.

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• value types in the vm

  - by john.rose

  value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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• What should you bring to the table as a Software Architect?

  - by Ahmad Mageed

  There have been many questions with good answers about the role of a Software Architect (SA) on StackOverflow and Programmers SE. I am trying to ask a slightly more focused question than those. The very definition of a SA is broad so for the sake of this question let's define a SA as follows: A Software Architect guides the overall design of a project, gets involved with coding efforts, conducts code reviews, and selects the technologies to be used. In other words, I am not talking about managerial rest and vest at the crest (further rhyming words elided) types of SAs. If I were to pursue any type of SA position I don't want to be away from coding. I might sacrifice some time to interface with clients and Business Analysts etc., but I am still technically involved and I'm not just aware of what's going on through meetings. With these points in mind, what should a SA bring to the table? Should they come in with a mentality of "laying down the law" (so to speak) and enforcing the usage of certain tools to fit "their way," i.e., coding guidelines, source control, patterns, UML documentation, etc.? Or should they specify initial direction and strategy then be laid back and jump in as needed to correct the ship's direction? Depending on the organization this might not work. An SA who relies on TFS to enforce everything may struggle to implement their plan at an employer that only uses StarTeam. Similarly, an SA needs to be flexible depending on the stage of the project. If it's a fresh project they have more choices, whereas they might have less for existing projects. Here are some SA stories I have experienced as a way of sharing some background in hopes that answers to my questions might also shed some light on these issues: I've worked with an SA who code reviewed literally every single line of code of the team. The SA would do this for not just our project but other projects in the organization (imagine the time spent on this). At first it was useful to enforce certain standards, but later it became crippling. FxCop was how the SA would find issues. Don't get me wrong, it was a good way to teach junior developers and force them to think of the consequences of their chosen approach, but for senior developers it was seen as somewhat draconian. One particular SA was against the use of a certain library, claiming it was slow. This forced us to write tons of code to achieve things differently while the other library would've saved us a lot of time. Fast forward to the last month of the project and the clients were complaining about performance. The only solution was to change certain functionality to use the originally ignored approach despite early warnings from the devs. By that point a lot of code was thrown out and not reusable, leading to overtime and stress. Sadly the estimates used for the project were based on the old approach which my project was forbidden from using so it wasn't an appropriate indicator for estimation. I would hear the PM say "we've done this before," when in reality they had not since we were using a new library and the devs working on it were not the same devs used on the old project. The SA who would enforce the usage of DTOs, DOs, BOs, Service layers and so on for all projects. New devs had to learn this architecture and the SA adamantly enforced usage guidelines. Exceptions to usage guidelines were made when it was absolutely difficult to follow the guidelines. The SA was grounded in their approach. Classes for DTOs and all CRUD operations were generated via CodeSmith and database schemas were another similar ball of wax. However, having used this setup everywhere, the SA was not open to new technologies such as LINQ to SQL or Entity Framework. I am not using this post as a platform for venting. There were positive and negative aspects to my experiences with the SA stories mentioned above. My questions boil down to: What should an SA bring to the table? How can they strike a balance in their decision making? Should one approach an SA job (as defined earlier) with the mentality that they must enforce certain ground rules? Anything else to consider? Thanks! I'm sure these job tasks are easily extended to people who are senior devs or technical leads, so feel free to answer at that capacity as well.

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• Removing Duplicate Data From SQL Query Output For Display On A Web Page [migrated]

  - by doubleJ

  I had asked a similar question on stackoverflow but didn't really get anywhere. This page shows the output that I'm currently getting from my MSSQL server. I have a table of venue information (name, address, etc...) that our events happen on. Separately, I have a table of the actual events that are scheduled (an event may happen multiple times in one day and/or over multiple days). I join those tables with this query: <?php try { $dbh = new PDO("sqlsrv:Server=localhost;Database=Sermons", "", ""); $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $sql = "SELECT TOP (100) PERCENT dbo.TblSermon.Day, dbo.TblSermon.Date, dbo.TblSermon.Time, dbo.TblSermon.Speaker, dbo.TblSermon.Series, dbo.TblSermon.Sarasota, dbo.TblSermon.NonFlc, dbo.TblJoinSermonLocation.MeetingName, dbo.TblLocation.Location, dbo.TblLocation.Pastors, dbo.TblLocation.Address, dbo.TblLocation.City, dbo.TblLocation.State, dbo.TblLocation.Zip, dbo.TblLocation.Country, dbo.TblLocation.Phone, dbo.TblLocation.Email, dbo.TblLocation.WebAddress FROM dbo.TblLocation RIGHT OUTER JOIN dbo.TblJoinSermonLocation ON dbo.TblLocation.ID = dbo.TblJoinSermonLocation.Location RIGHT OUTER JOIN dbo.TblSermon ON dbo.TblJoinSermonLocation.Sermon = dbo.TblSermon.ID WHERE (dbo.TblSermon.Date >= { fn NOW() }) ORDER BY dbo.TblSermon.Date, dbo.TblSermon.Time"; $stmt = $dbh->prepare($sql); $stmt->execute(); $stmt->setFetchMode(PDO::FETCH_ASSOC); foreach ($stmt as $row) { echo "<pre>"; print_r($row); echo "</pre>"; } unset($row); $dbh = null; } catch(PDOException $e) { echo $e->getMessage(); } ?> So, as it loops through the query results, it creates an array for each record and ends up like this: Array ( [Day] => Tuesday [Date] => 2012-10-30 00:00:00.000 [Time] => 07:00 PM [Speaker] => Keith Moore [Location] => The Ark Church [Pastors] => Alan & Joy Clayton [Address] => 450 Humble Tank Rd. [City] => Conroe [State] => TX [Zip] => 77305.0 [Phone] => (936) 756-1988 [Email] => [email protected] [WebAddress] => http://www.thearkchurch.org ) Array ( [Day] => Wednesday [Date] => 2012-10-31 00:00:00.000 [Time] => 07:00 PM [Speaker] => Keith Moore [Location] => The Ark Church [Pastors] => Alan & Joy Clayton [Address] => 450 Humble Tank Rd. [City] => Conroe [State] => TX [Zip] => 77305.0 [Phone] => (936) 756-1988 [Email] => [email protected] [WebAddress] => http://www.thearkchurch.org ) Array ( [Day] => Tuesday [Date] => 2012-11-06 00:00:00.000 [Time] => 07:00 PM [Speaker] => Keith Moore [Location] => Fellowship Of Faith Christian Center [Pastors] => Michael & Joan Kalstrup [Address] => 18999 Hwy. 59 [City] => Oakland [State] => IA [Zip] => 51560.0 [Phone] => (712) 482-3455 [Email] => [email protected] [WebAddress] => http://www.fellowshipoffaith.cc ) Array ( [Day] => Wednesday [Date] => 2012-11-14 00:00:00.000 [Time] => 07:00 PM [Speaker] => Keith Moore [Location] => Faith Family Church [Pastors] => Michael & Barbara Cameneti [Address] => 8200 Freedom Ave NW [City] => Canton [State] => OH [Zip] => 44720.0 [Phone] => (330) 492-0925 [Email] => [WebAddress] => http://www.myfaithfamily.com ) As you can see, The Ark Church and its associated contact information is duplicated, so when I work with those arrays and output them to the page, I see a bunch of duplicate content. I'd like to remove the duplicate information so that I get results similar to this: The Ark Church Alan & Joy Clayton 450 Humble Tank Rd. Conroe, TX 77305 (936) 756-1988 [email protected] http://www.thearkchurch.org Meetings: Tuesday, 2012-10-30 07:00 PM Wednesday, 2012-10-31 07:00 PM Fellowship Of Faith Christian Center Michael & Joan Kalstrup 18999 Hwy. 59 Oakland, IA 51560 (712) 482-3455 [email protected] http://www.fellowshipoffaith.cc Meetings: Tuesday, 2012-11-06 07:00 PM Faith Family Church Michael & Barbara Cameneti 8200 Freedom Ave NW Canton, OH 44720 (330) 492-0925 http://www.myfaithfamily.com Meetings: Wednesday, 2012-11-14 07:00 PM It doesn't necessarily have to end up like that (I'm not looking for code specific for these results, but a concept of how to not show the duplicated information). I'm assuming that an additional foreach or while will do it, but I haven't figured out any logic that says <?php if ($location == $previouslocation) echo ""; ?>.

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• BizTalk &ndash; Routing failure on Delivery Notifications (BizTalk 2006 R2 to 2013)

  - by S.E.R.

  Originally posted on: http://geekswithblogs.net/SERivas/archive/2013/11/11/biztalk-routing-failure-on-delivery-notifications.aspxThis is a detailed explanation of a something I posted a few month ago on stackoverflow, concerning a weird behavior (a bug, really…) of the delivery notifications in BizTalk. Reminder: what are delivery notifications Mechanism BizTalk has the ability to automatically publish positive acknowledgments (ACK) when it has succeeded transmitting a message or negative acknowledgments (NACK) in case of a transmission failure. Orchestrations can use delivery notifications to subscribe to those ACKs and NACKs in order to know if a message sent on a one-way send port has been successfully transmitted. Delivery Notifications can be “activated” in two ways: The most common and easy way is to set the Delivery Notification property of a logical send port (in the orchestration designer) to Transmitted: Another way is to set the BTS.AckRequired context property of the message to be sent to true: NOTE: fundamentally, those methods are strictly equivalent since the fact of setting the Delivery Notification to Transmitted on the send port only tells BizTalk the BTS.AckRequired context property has to be set to true on the outgoing message. Related context properties ACKs and NACKs have a common set of propoted context properties, which are : Propriété Description AckType Equals ACK when successful or NACK otherwise AckID MessageID of the message concerned by the acknowledgment AckOwnerID InstanceID of the instance associated with the acknowledgment AckSendPortID ID of the send port AckSendPortName Name of the send port AckOutboundTransportLocation URI of the send port AckReceivePortID ID of the port the message came from AckReceivePortName Name of the port the message came from AckInboundTransportLocation URI of the port the message came from Detailed behavior The way Delivery Notifications are handled by BizTalk is peculiar compared to the standard behavior of the Message Box: if no active subscription exists for the acknowledgment, it is simply discarded. The direct consequence of this is that there can be no routing failure for an acknowledgment, and an acknowledgment cannot be suspended. Moreover, when a message is sent to a send port where Delivery Notification = Transmitted, a correlation set is initialized and a correlation token is attached to the message (Context property: CorrelationToken). This correlation token will also be attached to the acknowledgment. So when the acknowledgment is issued, it is automatically routed to the source orchestration. Finally, when a NACK is received by the source orchestration, a DeliveryFailureException is thrown, which can be caught in Catch section. Context of the problem Consider this scenario: In an orchestration, Delivery Notifications are activated on a One-Way send port In case of a transmission failure, the messaging instance is suspended and the orchestration catches an exception (DeliveryFailureException). When the exception is caught, the orchestration does some logging and then terminates (thanks to a Terminate shape). So that leaves only the suspended messaging instance, waiting to be resumed. Symptoms Once the problem that caused the transmission failure is solved, the messaging instance is resumed. Considering what was said in the reminder, we would expect the instance to complete, leaving no active or suspended instance. Nevertheless, the result is that the messaging instance is once more suspended, this time because of a routing failure: The routing failure report shows that the suspended message has the following attached properties: Explanation Those properties clearly indicate that the message being suspended is an acknowledgment (ACK in this case), which was published in the message box and was supended because no subscribers were found. This makes sense, since the source orchestration was terminated before we resumed the messaging instance. So its subscription to the acknowledgments was no longer active when the ACK was published, which explains the routing failure. But this behavior is in direct contradiction with what was said earlier: an acknowledgment must be discarded when no subscriber is found and therefore should not be suspended. Cause It is indeed an outright bug, which appeared with the SP1 of BizTalk 2006 R2 and was never corrected since then: not in the next 4 CUs, not in BizTalk 2009, not in 2010 and not event in 2013 – though I haven’t tested CU1 and CU2 for this last edition, but I bet there is nothing to be expected from those CUs (on this particular point). Side effects This bug can have pretty nasty side effects: this behavior can be propagated to other ports, due to routing mechanisms. For instance: you have configured the ESB Toolkit and have activated the “Enable routing failure for failed messages”. The result will be that the ESB Exception SQL send port will also try and publish ACKs or NACKs concerning its own messaging instances. In itself, this is already messy, but remember that those acknowledgments will also have the source correlation token attached to them… See how far it goes? Well, actually there is more: in SQL send ports, transactions will be rolled back because of the routing failure (I guess it also happens with other adapters - like Oracle, but I haven’t tested them). Again, think of what happens when the send port is the ESB Exception send port: your BizTalk box is going mad, but you have no idea since no exception can be written in the exception database! All of this can be tricky to diagnose, I can tell you that… Solution There is no real solution, only a work-around, but it won’t solve all of the problems and side effects. The idea is to create an orchestration which subscribes to all acknowledgments. That is to say: The message type of the incoming message will be XmlDocument The BTS.AckType property exists The logical receive port will use direct binding By doing so, all acknowledgments will be consumed by an instance of this orchestration, thus avoiding the routing failure. Here is an example of what this orchestration could look like: In order not to pollute the HAT and the DTA Db (after all, this orchestration is only meant to be a palliative to some faulty internal BizTalk mechanism, so there should be no trace of its execution), all tracking must be deactivated:

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• Some New .NET Downloads and Resources

  - by Kevin Grossnicklaus

  Last week I was fortunate enough to spend time in Redmond on Microsoft’s campus for the 2011 Microsoft MVP Summit.  It was great to hang out with a number of old friends and get the opportunity to talk tech with the various product teams up at Microsoft.  The weather wasn’t exactly sunny but Microsoft always does a great job with the Summit and everyone had a blast (heck, I even got to run the bases at SafeCo field) While much of what we saw is covered under NDA, there a ton of great things in the pipeline from Microsoft and many things that are already available (or just became so) that I wasn’t necessarily aware of.  The purpose of this post is to share some of the info I learned on resources and tools available to .NET developers today.  Please let me know if you have any questions (or if you know of something else cool which might benefit others). Enjoy! Visual Studio 2010 SP1 Microsoft has issued the RTM release of Visual Studio 2010 SP1.  You can download the full SP1 on MSDN as of today (March 10th to the general public) and take advantage of such things as: Silverlight 4 is included in the box (as opposed to a separate install) Silverlight 4 Profiling WCF RIA Services SP1 Intellitrace for 64-bit and SharePoint ASP.NET now easily supports IIS Express and SQL CE Want a description of all that’s new beyond the above biased list (which arguably only contains items I think are important)?  Check out this KB article. Portable Library Tools CTP Without much fanfare Microsoft has released a CTP of a new add-in to Visual Studio 2010 which simplifies code sharing between projects targeting different runtimes (i.e. Silverlight, WPF, Win7 Phone, XBox).   With this Add-In installed you can add a new project of type “Portable Library” and specify which platforms you wish to target.  Once that is done, any code added to this library will be limited to use only features which are common to all selected frameworks.  Other projects can now reference this portable library and be provided assemblies custom built to their environment.  This greatly simplifies the current process of sharing linked files between platforms like WPF and Silverlight.  You can find out more about this CTP and how it works on this great blog post. Visual Studio Async CTP Microsoft has also released a CTP of a set of language and framework enhancements to provide a much more powerful asynchronous programming model.   Due to the focus on async programming in all types of platforms (and it being the ONLY option in Silverlight and Win7 phone) a move towards a simpler and more understandable model is always a good thing. This CTP (called Visual Studio Async CTP) can be downloaded here.  You can read more about this CTP on this blog post. MSDN Code Samples Gallery Microsoft has also launched new code samples gallery on their MSDN site: http://code.msdn.microsoft.com/.   This site allows you to easily search for small samples of code related to a particular technology or platform.  If a sample of code you are looking for is not found, you can request one via the site and other developers can see your request and provide a sample to the site to suit your needs.  You can also peruse requested samples and, if you find a scenario where you can provide value, upload your own sample for the benefit of others.  Samples are packaged into the VS .vsix format and include any necessary references/dependencies.  By using .vsix as the deployment mechanism, as samples are installed from the site they are kept in your Visual Studio 2010 Samples Gallery and kept for your future reference. If you get a chance, check out the site and see how it is done.  Although a somewhat simple concept, I was very impressed with their implementation and the way they went about trying to suit a need.  I’ll definitely be looking there in the future as need something or want to share something. MSDN Search Capabilities Another item I learned recently and was not aware of (that might seem trivial to some) is the power of the MSDN site’s search capabilities.  Between the Code Samples Gallery described above and the search enhancements on MSDN, Microsoft is definitely investing in their platform to help provide developers of all skill levels the tools and resources they need to be successful. What do I mean by the MSDN search capability and why should you care? If you go to the MSDN home page (http://msdn.microsoft.com) and use the “Search MSDN with Big” box at the very top of the page you will see some very interesting results.  First, the search actually doesn’t just search the MSDN library it searches: MSDN Library All Microsoft Blogs CodePlex StackOverflow Downloads MSDN Magazine Support Knowledgebase (I’m not sure it even ends there but the above are all I know of) Beyond just searching all the above locations, the results are formatted very nicely to give some contextual information based on where the result came from.  For example, if a keyword search returned results from CodePlex, each row in the search results screen would include a large amount of information specific to CodePlex such as: Looking at the above results immediately tells you everything from the page views to the CodePlex ratings.  All in all, knowing that this much information is indexed and available from a single search location will lead me to utilize this as one of my initial searches for development information.

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

  - by Christian Basar

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

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• T-SQL Tuesday #34: Help! I Need Somebody!

  - by Most Valuable Yak (Rob Volk)

  Welcome everyone to T-SQL Tuesday Episode 34!  When last we tuned in, Mike Fal (b|t) hosted Trick Shots.  These highlighted techniques or tricks that you figured out on your own which helped you understand SQL Server better. This month, I'm asking you to look back this past week, year, century, or hour...to a time when you COULDN'T figure it out.  When you were stuck on a SQL Server problem and you had to seek help. In the beginning... SQL Server has changed a lot since I started with it.  <Cranky Old Guy> Back in my day, Books Online was neither.  There were no blogs. Google was the third-place search site. There were perhaps two or three community forums where you could ask questions.  (Besides the Microsoft newsgroups...which you had to access with Usenet.  And endure the wrath of...Celko.)  Your "training" was reading a book, made from real dead trees, that you bought from your choice of brick-and-mortar bookstore. And except for your local user groups, there were no conferences, seminars, SQL Saturdays, or any online video hookups where you could interact with a person. You'd have to call Microsoft Support...on the phone...a LANDLINE phone.  And none of this "SQL Family" business!</Cranky Old Guy> Even now, with all these excellent resources available, it's still daunting for a beginner to seek help for SQL Server.  The product is roughly 1247.4523 times larger than it was 15 years ago, and it's simply impossible to know everything about it.*  So whether you are a beginner, or a seasoned pro of over a decade's experience, what do you do when you need help on SQL Server? That's so meta... In the spirit of offering help, here are some suggestions for your topic: Tell us about a person or SQL Server community who have been helpful to you.  It can be about a technical problem, or not, e.g. someone who volunteered for your local SQL Saturday.  Sing their praises!  Let the world know who they are! Do you have any tricks for using Books Online?  Do you use the locally installed product, or are you completely online with BOL/MSDN/Technet, and why? If you've been using SQL Server for over 10 years, how has your help-seeking changed? Are you using Twitter, StackOverflow, MSDN Forums, or another resource that didn't exist when you started? What made you switch? Do you spend more time helping others than seeking help? What motivates you to help, and how do you contribute? Structure your post along the lyrics to The Beatles song Help! Audio or video renditions are particularly welcome! Lyrics must include reference to SQL Server terminology or community, and performances must be in your voice or include you playing an instrument. These are just suggestions, you are free to write whatever you like.  Bonus points if you can incorporate ALL of these into a single post.  (Or you can do multiple posts, we're flexible like that.)  Help us help others by showing how others helped you! Legalese, Your Rights, Yada yada... If you would like to participate in T-SQL Tuesday please be sure to follow the rules below: Your blog post must be published between Tuesday, September 11, 2012 00:00:00 GMT and Wednesday, September 12, 2012 00:00:00 GMT. Include the T-SQL Tuesday logo (above) and hyperlink it back to this post. If you don’t see your post in trackbacks, add the link to the comments below. If you are on Twitter please tweet your blog using the #TSQL2sDay hashtag.  I can be contacted there as @sql_r, in case you have questions or problems with comments/trackback.  I'll have a follow-up post listing all the contributions as soon as I can. Thank you all for participating, and special thanks to Adam Machanic (b|t) for all his help and for continuing this series!

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• Thread.Interrupt Is Evil

  - by Alois Kraus

  Recently I have found an interesting issue with Thread.Interrupt during application shutdown. Some application was crashing once a week and we had not really a clue what was the issue. Since it happened not very often it was left as is until we have got some memory dumps during the crash. A memory dump usually means WindDbg which I really like to use (I know I am one of the very few fans of it).  After a quick analysis I did find that the main thread already had exited and the thread with the crash was stuck in a Monitor.Wait. Strange Indeed. Running the application a few thousand times under the debugger would potentially not have shown me what the reason was so I decided to what I call constructive debugging. I did create a simple Console application project and try to simulate the exact circumstances when the crash did happen from the information I have via memory dump and source code reading. The thread that was  crashing was actually MS code from an old version of the Microsoft Caching Application Block. From reading the code I could conclude that the main thread did call the Dispose method on the CacheManger class which did call Thread.Interrupt on the cache scavenger thread which was just waiting for work to do. My first version of the repro looked like this   static void Main(string[] args) { Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); } static void ThreadFunc() { while (true) { object value = Dequeue(); // block until unblocked or awaken via ThreadInterruptedException } } static object WaitObject = new object(); static object Dequeue() { object lret = "got value"; try { lock (WaitObject) { } } catch (ThreadInterruptedException) { Console.WriteLine("Got ThreadInterruptException"); lret = null; } return lret; } I do start a background thread and call Thread.Interrupt on it and then directly let the application terminate. The thread in the meantime does plenty of Monitor.Enter/Leave calls to simulate work on it. This first version did not crash. So I need to dig deeper. From the memory dump I did know that the finalizer thread was doing just some critical finalizers which were closing file handles. Ok lets add some long running finalizers to the sample. class FinalizableObject : CriticalFinalizerObject { ~FinalizableObject() { Console.WriteLine("Hi we are waiting to finalize now and block the finalizer thread for 5s."); Thread.Sleep(5000); } } class Program { static void Main(string[] args) { FinalizableObject fin = new FinalizableObject(); Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); GC.KeepAlive(fin); // prevent finalizing it too early // After leaving main the other thread is woken up via Thread.Abort // while we are finalizing. This causes a stackoverflow in the CLR ThreadAbortException handling at this time. } With this changed Main method and a blocking critical finalizer I did get my crash just like the real application. The funny thing is that this is actually a CLR bug. When the main method is left the CLR does suspend all threads except the finalizer thread and declares all objects as garbage. After the normal finalizers were called the critical finalizers are executed to e.g. free OS handles (usually). Remember that I did call Thread.Interrupt as one of the last methods in the Main method. The Interrupt method is actually asynchronous and does wake a thread up and throws a ThreadInterruptedException only once unlike Thread.Abort which does rethrow the exception when an exception handling clause is left. It seems that the CLR does not expect that a frozen thread does wake up again while the critical finalizers are executed. While trying to raise a ThreadInterrupedException the CLR goes down with an stack overflow. Ups not so nice. Why has this nobody noticed for years is my next question. As it turned out this error does only happen on the CLR for .NET 4.0 (x86 and x64). It does not show up in earlier or later versions of the CLR. I have reported this issue on connect here but so far it was not confirmed as a CLR bug. But I would be surprised if my console application was to blame for a stack overflow in my test thread in a Monitor.Wait call. What is the moral of this story? Thread.Abort is evil but Thread.Interrupt is too. It is so evil that even the CLR of .NET 4.0 contains a race condition during the CLR shutdown. When the CLR gurus can get it wrong the chances are high that you get it wrong too when you use this constructs. If you do not believe me see what Patrick Smacchia does blog about Thread.Abort and List.Sort. Not only the CLR creators can get it wrong. The BCL writers do sometimes have a hard time with correct exception handling as well. If you do tell me that you use Thread.Abort frequently and never had problems with it I do suspect that you do not have looked deep enough into your application to find such sporadic errors.

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• University teaches DOS-style C++, how to deal with it

  - by gaidal

  Half a year ago I had a look at available programming educations. I chose this one because unlike most of the choices: The majority of the courses seemed to be about something concrete and useful; the languages used are C++ and Java which are platform-independent; later courses include developing for mobile devices and a course on Android development, which seemed modern and relevant. Now after two introductory courses we're just starting with C++, and my programming professor seems a bit weird. He's tested us on things like "why should you use constants" and "why are globals bad" in a kind of mechanical way, without much context, before teaching actual programming. His handouts use system("pause"), system("cls"), and getch() from some conio.h that seems ancient according to what I've read. I just did a task that was about printing the "ASCII letters from 32 to 255" (huh?), with an example picture showing a table with Windows' Extended ASCII - of course I got other results for 128-255 on my Arch Linux that uses Unicode, and this isn't mentioned at all. I don't know, it just doesn't seem right... As if he is teaching programming because he has to, perhaps? Should I bring such things up? Hmm. I was looking forward to learning from someone who really knows stuff, and in an academic, rigorous way, like SICP or something. Aren't professors in programming supposed to be like that? I studied math for a while and every teacher and assistant there were really precise about what they said, but this is my second programming teacher that is sort of disappointing. Oh well. Now, question: Is this what to expect from universities or Not OK, and how do I deal with it? I have never touched the language C++ (or C) until now, and am not the right person to jump up and say "This is So Wrong!", so if I google something and find 10 people who say "xxx is blasphemy", how do I skillfully communicate this? I do think it would be better for those classmates who are total beginners not to learn bad habits (such as these vibes of total ignorance of other platforms!) during the upcoming courses, but don't want to disrespect the teacher. I don't know if it's reasonable or just cocky to bring up things like "what about other platforms?" or "but what about this article or stackoverflow answer that I read that said..." for every assignment? Or, if he keeps ignoring non-Windows-programming, should I give up and focus on my own projects or somehow argue that this really isn't OK nowadays? Are there any programming teachers out there, what do you think? By the way these are web-based courses, all interaction between teachers and students takes place in a forum. EDIT: A few answers seem to be making some incorrect assumptions, so maybe I should add a few things. I have been doing programming for fun on and off for 10 years, am pretty comfortable in 3 languages and read programming blogs et c regularly. Also, I feel kind of done being a student, having a degree in another field. I just need another, relevant diploma to work as a programmer, so I'm going back for that. Studying computer science for 5 years is not for me anymore, even though I enjoy learning and solving problems in my free time. Second, let me highlight that I don't expect it to be like the industry at all, quite the contrary. I expect it to be academic, dry and unnecessarily correct. No, it's not just math. Every professor I have had in math, or Japanese (major) or Chinese (minor) have been very very academic, discussing subtle points for hours with passion. But the courses I'm taking now and a previous one in programming don't seem serious. They neither resemble industry NOR academia. That is the problem. And it's not because I can't learn programming anyway. Third, I don't necessarily want to learn C++ or Android development, and I know I could teach myself those and anything else if I wanted to. But I am going back to school anyway, and those platform-independent languages and mobile stuff made me think that maybe they're serious about teaching something relevant here. Seems like I got this wrong, but we'll see.

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• Some Early Considerations

  - by Chris Massey

  Following on from my previous post, I want to say "thank you" to everyone who has got in touch and got involved – you are pioneers! An update on where we are right now: paper prototypes v1 To be more specific, we’ve picked two of the ideas that seem to have more pros than cons, turned them into Balsamiq mockups, and are getting them fleshed out with realistic content. We’ll initially make these available to the aforementioned pioneers (thank you again), roll in the feedback, and then open up to get more data on what works and what doesn’t. If you’ve got any questions about this (or what we’re working on right now), feel free to ask me in the comments below. I’ve had a few people express an interest in the process we’re going through, and I’m more than happy to share details more frequently as we go along – not least because you, dear reader, will help us stay on target and create something Good. To start with, here’s a quick flashback to bring you all up to speed. A Brief Retrospective As you may already know, we’re creating a new publishing asset specifically focused on providing great content for web developers. We don’t yet know exactly what this thing will look like, or exactly how it will work, but we know we want to create something that is useful different. For my part, I’m seriously excited at the prospect of building a genuinely digital publishing system (as opposed to what most publishing is these days, which is print-style publishing which just happens to be on the web). The main challenge at this point is working out our build-measure-assess loop to speed up our experimental turn-around, and that’ll get better as we run more trials. Of course, there are a few things we’ve been pondering at this early conceptual stage: Do we publishing about heterogeneous technology stacks from day 1, or do we start with ASP.NET (which we’re familiar with) & branch out later? There are challenges with either approach. What publishing "modes" are already being well-handled? For example, the likes of Pluralsight, TekPub, and Treehouse have pretty much nailed video training (debate about price, if you like), and unless we think we can do it faster / better / cheaper (unlikely, for the record), we should leave them to it. Where should we base whatever we create? Should we create a completely new asset under a new name, graft something onto Simple-Talk (like the labs), or just build something directly into Simple-Talk? It sounds trivial, but it does have at least some impact on infrastructure and what how we manage the different types of content we (will) have. Are there any obvious problems or niches that we think could address really well, or should we just throw ideas out and see what readers respond to? What kind of users do we want to provide for? This actually deserves a little bit of unpacking… Why are you here? We currently divide readers into (broadly) the categories: Category 1: I know nothing about X, and I’d like to learn about it. Category 2: I know something about X, but I’d like to learn how to do something specific with it. Category 3: Ah man, I have a problem with X, and I need to fix it now. Now that I think about it, I might also include a 4th class of reader: Category 4: I’m looking for something interesting to engage my brain. These are clearly task-based categorizations, and depending on which task you’re performing when you arrive here, you’re going to need different types of content, or will have specific discovery needs. One of the questions that’s at the back of my mind whenever I consider a new idea is “How many of the categories will this satisfy?” As an example, typical video training is very well suited to categories 1, 2, and 4. StackOverflow is very well suited to category 3, and serves as a sign-posting system to the rest. Clearly it’s not necessary to satisfy every category need to be useful and popular, but being aware of what behavior readers might be exhibiting when they arrive will help us tune our ideas appropriately. < / Flashback > We don’t have clean answers to most of these considerations – they’re things we’re aware of, and each idea we look at is going to be best suited to a different mix of the options I’ve described. Our first experimental loop will be coming full circle in the next few days, so we should start to see how the different possibilities vary between ideas. Free to chime in with questions and suggestions about anything I’ve just brain-dumped, or at any stage as we go along. If you see anything that intrigued or enrages you, or just have an idea you’d like to share, I’d love to hear from you.

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• Building a Repository Pattern against an EF 5 EDMX Model - Part 1

  - by Juan

  I am part of a year long plus project that is re-writing an existing application for a client.  We have decided to develop the project using Visual Studio 2012 and .NET 4.5.  The project will be using a number of technologies and patterns to include Entity Framework 5, WCF Services, and WPF for the client UI.This is my attempt at documenting some of the successes and failures that I will be coming across in the development of the application.In building the data access layer we have to access a database that has already been designed by a dedicated dba. The dba insists on using Stored Procedures which has made the use of EF a little more difficult.  He will not allow direct table access but we did manage to get him to allow us to use Views.  Since EF 5 does not have good support to do Code First with Stored Procedures, my option was to create a model (EDMX) against the existing database views.   I then had to go select each entity and map the Insert/Update/Delete functions to their respective stored procedure. The next step after I had completed mapping the stored procedures to the entities in the EDMX model was to figure out how to build a generic repository that would work well with Entity Framework 5.  After reading the blog posts below, I adopted much of their code with some changes to allow for the use of Ninject for dependency injection.http://www.tcscblog.com/2012/06/22/entity-framework-generic-repository/ http://www.tugberkugurlu.com/archive/generic-repository-pattern-entity-framework-asp-net-mvc-and-unit-testing-triangle IRepository.cs public interface IRepository : IDisposable where T : class { void Add(T entity); void Update(T entity, int id); T GetById(object key); IQueryable Query(Expression> predicate); IQueryable GetAll(); int SaveChanges(); int SaveChanges(bool validateEntities); } GenericRepository.cs public abstract class GenericRepository : IRepository where T : class { public abstract void Add(T entity); public abstract void Update(T entity, int id); public abstract T GetById(object key); public abstract IQueryable Query(Expression> predicate); public abstract IQueryable GetAll(); public int SaveChanges() { return SaveChanges(true); } public abstract int SaveChanges(bool validateEntities); public abstract void Dispose(); } One of the issues I ran into was trying to do an update. I kept receiving errors so I posted a question on Stack Overflow http://stackoverflow.com/questions/12585664/an-object-with-the-same-key-already-exists-in-the-objectstatemanager-the-object and came up with the following hack. If someone has a better way, please let me know. DbContextRepository.cs public class DbContextRepository : GenericRepository where T : class { protected DbContext Context; protected DbSet DbSet; public DbContextRepository(DbContext context) { if (context == null) throw new ArgumentException("context"); Context = context; DbSet = Context.Set(); } public override void Add(T entity) { if (entity == null) throw new ArgumentException("Cannot add a null entity."); DbSet.Add(entity); } public override void Update(T entity, int id) { if (entity == null) throw new ArgumentException("Cannot update a null entity."); var entry = Context.Entry(entity); if (entry.State == EntityState.Detached) { var attachedEntity = DbSet.Find(id); // Need to have access to key if (attachedEntity != null) { var attachedEntry = Context.Entry(attachedEntity); attachedEntry.CurrentValues.SetValues(entity); } else { entry.State = EntityState.Modified; // This should attach entity } } } public override T GetById(object key) { return DbSet.Find(key); } public override IQueryable Query(Expression> predicate) { return DbSet.Where(predicate); } public override IQueryable GetAll() { return Context.Set(); } public override int SaveChanges(bool validateEntities) { Context.Configuration.ValidateOnSaveEnabled = validateEntities; return Context.SaveChanges(); } #region IDisposable implementation public override void Dispose() { if (Context != null) { Context.Dispose(); GC.SuppressFinalize(this); } } #endregion IDisposable implementation } At this point I am able to start creating individual repositories that are needed and add a Unit of Work.  Stay tuned for the next installment in my path to creating a Repository Pattern against EF5.

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• returning correct multiTouch id

  - by Max

  I've spent countless hours on reading tutorials and looking at every question related to multiTouch from here and Stackoverflow. But I just cannot figure out how to do this correctly. I use a loop to get my pointerId, I dont see alot of people doing this but its the only way I've managed to get it somewhat working. I have two joysticks on my screen, one for moving and one for controlling my sprites rotation and the angle he shoots, like in Monster Shooter. Both these work fine. My problem is that when I Move my sprite at the same time as Im shooting, my touchingPoint for my movement is set to the touchingPoint of my shooting, since the x and y is higher on the touchingPoint of my shooting (moving-stick on left side of screen, shooting-stick on right side), my sprite speeds up, this creates an unwanted change in speed for my sprite. I will post my entire onTouch method here with some variable-changes to make it more understandable. Since I do not know where Im going wrong. public void update(MotionEvent event) { if (event == null && lastEvent == null) { return; } else if (event == null && lastEvent != null) { event = lastEvent; } else { lastEvent = event; } int pointerCount = event.getPointerCount(); for (int i = 0; i < pointerCount; i++) { int x = (int) event.getX(i); int y = (int) event.getY(i); int id = event.getPointerId(i); int action = event.getActionMasked(); int actionIndex = event.getActionIndex(); String actionString; switch (action) { case MotionEvent.ACTION_DOWN: actionString = "DOWN"; break; case MotionEvent.ACTION_UP: shooting=false; // when shooting is true, it shoots dragging=false; // when dragging is true, it moves actionString = "UP"; break; case MotionEvent.ACTION_POINTER_DOWN: actionString = "PNTR DOWN"; break; case MotionEvent.ACTION_POINTER_UP: shooting=false; dragging=false; actionString = "PNTR UP"; break; case MotionEvent.ACTION_CANCEL: shooting=false; dragging=false; actionString = "CANCEL"; break; case MotionEvent.ACTION_MOVE: try{ if((int) event.getX(id) > 0 && (int) event.getX(id) < touchingBox && (int) event.getY(id) > touchingBox && (int) event.getY(id) < view.getHeight()){ movingPoint.x = (int) event.getX(id); movingPoint.y = (int) event.getY(id); dragging = true; } else if((int) event.getX(id) > touchingBox && (int) event.getX(id) < view.getWidth() && (int) event.getY(id) > touchingBox && (int) event.getY(id) < view.getHeight()){ shootingPoint.x = (int) event.getX(id); shootingPoint.y = (int) event.getY(id); shooting=true; }else{ shooting=false; dragging=false; } }catch(Exception e){ } actionString = "MOVE"; break; default: actionString = ""; } Wouldnt post this much code if I wasnt at an absolute loss of what I'm doing wrong. I simply can not get a good understanding of how multiTouching works. basicly movingPoint changes for both my first and second finger. I bind it to a box, but aslong as I hold one finger within this box, it changes its value based on where my second finger touches. It moves in the right direction and nothing gives an error, the problem is the speed-change, its almost like it adds up the two touchingPoints.

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• The architecture and technologies to use for a secure, fast, reliable and easily scalable web application

  - by DSoul

  ^ For actual questions, skip to the lists down below I understand, that his is a vague topic, but please, before you turn the other way and disregard me, hear me out. I am currently doing research for a web application(I don't know if application is the correct word for it, but I will proceed w/ that for now), that one day might need to be everything mentioned in the title. I am bound by nothing. That means that every language, OS and framework is acceptable, but only if it proves it's usefulness. And if you are going to say, that scalability and speed depend on the code I write for this application, then I agree, but I am just trying to find something, that wouldn't stand in my way later on. I have done quite a bit reading on this subject, but I still don't have a clear picture, to what suits my needs, so I come to you, StackOverflow, to give me directions. I know you all must be wondering what I'm building, but I assure you, that it doesn't matter. I have heard of 12 factor app though, if you have any similar guidelines or what is, to suggest the please, go ahead. For the sake of keeping your answers as open as possible, I'm not gonna provide you my experience regarding anything written in this question. ^ Skippers, start here First off - the weights of the requirements are probably something like that (on a scale of 10): Security - 10 Speed - 5 Reliability (concurrency) - 7.5 Scalability - 10 Speed and concurrency are not a top priority, in the sense, that the program can be CPU intensive, and therefore slow, and only accept a not-that-high number of concurrent users, but both of these factors must be improvable by scaling the system Anyway, here are my questions: How many layers should the application have, so it would be future-proof and could best fulfill the aforementioned requirements? For now, what I have in mind is the most common version: Completely separated front end, that might be a web page or an MMI application or even both. Some middle-ware handling communication between the front and the back end. This is probably a server that communicates w/ the front end via HTTP. How the communication w/ the back end should be handled is probably dependent on the back end. The back end. Something that handles data through resources like DB and etc. and does various computations w/ the data. This, as the highest priority part of the software, must be easily spread to multiple computers later on and have no known security holes. I think ideally the middle-ware should send a request to a queue from where one of the back end processes takes this request, chops it up to smaller parts and buts these parts of the request back onto the same queue as the initial request, after what these parts will be then handled by other back end processes. Something *map-reduce*y, so to say. What frameworks, languages and etc. should these layers use? The technologies used here are not that important at this moment, you can ignore this part for now I've been pointed to node.js for this part. Do you guys know any better alternatives, or have any reasons why I should (not) use node.js for this particular job. I actually have no good idea, what to use for this job, there are too many options out there, so please direct me. This part (and the 2. one also, I think) depend a lot on the OS, so suggest any OSs alongside w/ the technologies/frameworks. Initially, all computers (or 1 for starters) hosting the back end are going to be virtual machines. Please do give suggestions to any part of the question, that you feel you have comprehensive knowledge and/or experience of. And also, point out if you feel that any part of the current set-up means an instant (or even distant) failure or if I missed a very important aspect to consider. I'm not looking for a definitive answer for how to achieve my goals, because there certainly isn't one, for I haven't provided you w/ all the required information. I'm just looking for recommendations and directions on what to look into. Also, bare in mind, that this isn't something that I have to get done quickly, to sell and let it be re-written by the new owner (which, I've been told for multiple times, is what I should aim for). I have all the time in the world and I really just want to learn doing something really high-end. Also, excuse me if my language isn't the best, I'm not a native. Anyway. Thanks in advance to anyone, who takes the time to help me out here. PS. When I do seem to come up w/ a good architecture/design for this project, I will certainly make it an open project and keep you guys up to date w/ it's development. As in what you could have told me earlier and etc. For obvious reasons the very same question got closed on SO, but could you guys still help me?.

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• FragmentStatePagerAdapter IllegalStateException: <MyFragment> is not currently in the FragmentManager

  - by Ixx

  I'm getting this on some cases, when going back to the activity, which uses a FragmentStatePagerAdapter, using back button of the devices. Not always. Not reproducible. I'm using support package v4, last revision (8). Already searched with google, no success finding a useful answer. Looking in the source, it's thrown here: FragmentManager.java @Override public void putFragment(Bundle bundle, String key, Fragment fragment) { if (fragment.mIndex < 0) { throw new IllegalStateException("Fragment " + fragment + " is not currently in the FragmentManager"); } bundle.putInt(key, fragment.mIndex); } But why is the index of fragment < 0 there? The code instantiating the fragments: @Override public Fragment getItem(int position) { Fragment fragment = null; switch(position) { case 0: fragment = Fragment1.newInstance(param1); break; case 1: fragment = MyFragment2.newInstance(param2, param3); break; } return fragment; } @Override public int getCount() { return 2; } I also can't debug through the source since the support package doesn't let me attach the source, for some reason... but that's a different question...

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• How to programmatically add x509 certificate to local machine store using c#

  - by David

  I understand the question title may be a duplicate but I have not found an answer for my situation yet so here goes; I have this simple peice of code // Convert the Filename to an X509 Certificate X509Certificate2 cert = new X509Certificate2(certificateFilePath); // Get the server certificate store X509Store store = new X509Store(StoreName.TrustedPeople, StoreLocation.LocalMachine); store.Open(OpenFlags.MaxAllowed); store.Add(cert); // x509 certificate created from a user supplied filename But keep being presented with an "Access Denied" exception. I have read some information that suggests using StorePermissions would solve my issue but I don't think this is relevant in my code. Having said that, I did test it to to be sure and I couldn't get it to work. I also found suggestions that changing folder permissions within Windows was the way to go and while this may work(not tested), it doesn't seem practical for what will become distributed code. I also have to add that as the code will be running as a service on a server, adding the certificates to the current user store also seems wrong. Is there anyway to programmatically add a certificate into the local machine store?

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• Unable to debug simple Java application in Eclipse. Cannot connect to VM. AGENT_ERROR_TRANSPORT_INIT(197)

  - by Heptaparaparshi

  When i try to debug a simple application in Eclipse i receive a following error: Cannot connect to VM com.sun.jdi.connect.TransportTimeoutException And console provides me with a lonely string: FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197) I have JRE 1.6, JRE 1.7 and JDK 1.7 installed. Tried all of them. I've seen tons of same topics, but not a single answer helped me to solve my issue. Here they are: 1) Disable Firewall. Doesn't help. I have latest Avast ver. 9.0 at the moment. I'm a bit suspicious about that software, because before updating my Avast i was able to debug in Eclipse. I think it may cause this error, but i do not have direct clues :). I may ping my machine, firewall doesn't block Eclipse traffic, etc. 2) Add strings to hosts file. No reaction. ::1 localhost.localdomain localhost 127.0.0.1 localhost 3) Changing Network Settings in Java Control Panel to "Direct" connection. Doubtful advice. Also read that thing: http://wiki.eclipse.org/Debug/FAQ Can anyone help me to find out what is happening? Or guide me in the right direction?

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• Business Objects Enterprise reporting using SDK client gives exception

  - by Dev_Karl

  Hi! We have a client that is using the SDK for invoking reports on the Business Objects Embedded Report Server. We can login, but when calling the openDocument method, something goes wrong. code: //logon IEnterpriseSession session = sessionMgr.logon(username, password, clusterNode, authType); .... clientDoc = reportAppFactory.openDocument(report, 0, locale); /*row 58 in exception*/ exception: com.crystaldecisions.sdk.occa.report.lib.ReportSDKServerException: Unable to connect to the server: . - Server not found or server may be down---- Error code:-2147217387 Error code name:connectServer at com.crystaldecisions.sdk.occa.managedreports.ras.internal.RASReportAppFactory.a(Unknown Source) at com.crystaldecisions.sdk.occa.managedreports.ras.internal.RASReportAppFactory.a(Unknown Source) at com.crystaldecisions.sdk.occa.managedreports.ras.internal.RASReportAppFactory.a(Unknown Source) at com.crystaldecisions.sdk.occa.managedreports.ras.internal.RASReportAppFactory.openDocument(Unknown Source) at com.reportclient.MyReportClient.getReportFromInfoStore(MyReportClient.java:58) ... 28 more Caused by: com.crystaldecisions.sdk.occa.report.lib.ReportSDKServerException: Unable to connect to the server: . - Server not found or server may be down---- Error code:-2147217387 Error code name:connectServer at com.crystaldecisions.sdk.occa.report.lib.ReportSDKServerException.throwReportSDKServerException(Unknown Source) at com.crystaldecisions.sdk.occa.managedreports.ras.internal.CECORBACommunicationAdapter.connect(Unknown Source) ... 32 more Caused by: com.crystaldecisions.enterprise.ocaframework.OCAFrameworkException$NotFoundInDirectory: Server not found or server may be down at com.crystaldecisions.enterprise.ocaframework.j.find(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.AbstractServerHandler.buildServerInfo(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.AbstractServerHandler.buildClusterInfo(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.aa.for(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.ServiceMgr.for(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.o.a(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.o.a(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.o.a(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.p.a(Unknown Source) at com.crystaldecisions.enterprise.ocaframework.ServiceMgr.getManagedService(Unknown Source) ... 33 more The communication obviously works when logging in. Please let me know if you got any ideas or know where I can go and look for the answer. :) Regards, Karl

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• Detect blocked popup in Chrome

  - by Andrew

  I am aware of javascript techniques to detect whether a popup is blocked in other browsers (as described in the answer to this question). Here's the basic test: var newWin = window.open(url); if(!newWin || newWin.closed || typeof newWin.closed=='undefined') { //POPUP BLOCKED } But this does not work in Chrome. The "POPUP BLOCKED" section is never reached when the popup is blocked. Of course, the test is working to an extent since Chrome doesn't actually block the popup, but opens it in a tiny minimized window at the lower right corner which lists "blocked" popups. What I would like to do is be able to tell if the popup was blocked by Chrome's popup blocker. I try to avoid browser sniffing in favor of feature detection. Is there a way to do this without browser sniffing? Edit: I have now tried making use of newWin.outerHeight, newWin.left, and other similar properties to accomplish this. Google Chrome returns all position and height values as 0 when the popup is blocked. Unfortunately, it also returns the same values even if the popup is actually opened for an unknown amount of time. After some magical period (a couple of seconds in my testing), the location and size information is returned as the correct values. In other words, I'm still no closer to figuring this out. Any help would be appreciated.

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• WPF - LayoutUpdated event firing repeatedly

  - by Drew Noakes

  I've been adding a bit of animation to my WPF application. Thanks to Dan Crevier's unique solution to animating the children of a panel combined with the awesome WPF Penner animations it turned out to be fairly straightforward to make one of my controls look great and have its children move about with some nice animation. Unfortunately this all comes with a performance overhead. I'm happy to have the performance hit when items are added/removed or the control is resized, but it seems that this perf hit occurs consistently throughout the application's lifetime, even when items are completely static. The PanelLayoutAnimator class uses an attached property to hook the UIElement.LayoutUpdated.aspx) event. When this event fires, render transforms are animated to cause the children to glide to their new positions. Unfortunately it seems that the LayoutUpdated event fires every second or so, even when nothing is happening in the application (at least I don't think my code's doing anything -- the app doesn't have focus and the mouse is steady.) As the reason for the event is not immediately apparent to the event handler, all children of the control have to be reevaluated. This event is being called about once a second when idle. The frequency increases when actually using the app. So my question is, how can I improve the performance here? Any answer that assists would be appreciated, but I'm currently stuck on these sub-questions: What causes the LayoutUpdated event to fire so frequently? Is this supposed to happen, and if not, how can I find out why it's firing and curtail it? Is there a more convenient way within the handler to know whether something has happened that might have moved children? If so, I could bail out early and avoid the overhead of looping each child. For now I will work around this issue by disabling animation when there are more than N children in the panel.

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• ASP.NET websites under IIS 7.5 (Windows 7) running extremely slow

  - by emzero

  I've just installed Windows 7 x64 Ultimate on my desktop PC. I installed IIS, Visual Studio 2008, registered ASP.NET, etc. I have this ASP.NET 3.5 website I'm working on running EXTREMELY slow on this new IIS. On STA and PROD servers (Windows 2003 Server) and on my old XP/IIS 5.1 everything runs smoothly. A page which usually takes 1-2 seconds to load is taking 8 seconds!!! I saw this post on IIS forum. It says something about Vista/7 not pooling connections (just to let you know, the website is running locally but it's connecting to a SQL Server 2005 hosted on a remote server). It seems that it takes a while to "start loading" the page... I mean, I click refresh and it stays for several seconds "Waiting for localhost"... Then when it gets response it loads the whole page normally... I don't have a clue how to force Win7/IIS7.5 to pool database connections. EDIT: I've created a new empty ASP.NET web application to see if the problems happens too. The answer is no, it responds fast as it should with an empty default page. Maybe is something related to the DB connection. I will do a further test. It should be a way to fix it... EDIT 2: Debugging the app I noticed that the delay occurs AFTER the execution of .NET code (Page_Load, etc)... so the delay seems to be somewhere when IIS serves the page to the browser.

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• Moq Testing a private method .Many posts but still cannot make one example work

  - by devnet247

  Hi, I have seen many posts and questions about "Mocking a private method" but still cannot make it work and not found a real answer. Lets forget the code smell and you should not do it etc.... From what I understand I have done the following: 1) Created a class Library "MyMoqSamples" 2) Added a ref to Moq and NUnit 3) Edited the AssemblyInfo file and added [assembly: InternalsVisibleTo("DynamicProxyGenAssembly2")] [assembly: InternalsVisibleTo("MyMoqSamples")] 4) Now need to test a private method.Since it's a private method it's not part of an interface. 5) added the following code [TestFixture] public class Can_test_my_private_method { [Test] public void Should_be_able_to_test_my_private_method() { //TODO how do I test my DoSomthing method } } public class CustomerInfo { public string Name { get; set; } public string Surname { get; set; } } public interface ICustomerService { List<CustomerInfo> GetCustomers(); } public class CustomerService: ICustomerService { public List<CustomerInfo> GetCustomers() { return new List<CustomerInfo> {new CustomerInfo {Surname = "Bloggs", Name = "Jo"}}; } protected virtual void DoSomething() { } } Could you provide me an example on how you would test my private method? Thanks a lot

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• T4 Toolbox - mixing class feature and statement blocks

  - by Mauricio Scheffer

  I'm a T4 newbie trying to use T4 Toolbox to generate F# code based on this answer, but it seems that class feature blocks can't be mixed with statement blocks. Here's my code: <#@ template language="C#" hostspecific="True" debug="True" #> <#@ output extension="txt" #> <#@ include file="T4Toolbox.tt" #> <# FSharpTemplate template = new FSharpTemplate(); template.Output.Project = @"..\Library1\Library1.fsproj"; template.Output.File = "Module2.fs"; template.Render(); #> <#+ class FSharpTemplate: Template { public override string TransformText() { #> module Module2 <# for (int i = 0; i < 10; i++) { #> <#= i #> <# } #> <#+ return this.GenerationEnvironment.ToString(); } } #> And I get this error: A Statement cannot appear after the first class feature in the template. Only boilerplate, expressions and other class features are allowed after the first class feature block. So... how can I rewrite the template to achieve this?

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• Using Visual Studio 2008 to Assemble, Link, Debug, and Execute MASM 6.11 Assembly Code

  - by Kreychek

  I would like to use Visual Studio 2008 to the greatest extent possible while effectively compiling/linking/building/etc code as if all these build processes were being done by the tools provided with MASM 6.11. The exact version of MASM does not matter, so long as it's within the 6.x range, as that is what my college is using to teach 16-bit assembly. I have done some research on the subject and have come to the conclusion that there are several options: Reconfigure VS to call the MASM 6.11 executables with the same flags, etc as MASM 6.11 would natively do. Create intermediary batch file(s) to be called by VS to then invoke the proper commands for MASM's linker, etc. Reconfigure VS's built-in build tools/rules (assembler, linker, etc) to provide an environment identical to the one used by MASM 6.11. Option (2) was brought up when I realized that the options available in VS's "External Tools" interface may be insufficient to correctly invoke MASM's build tools, thus a batch file to interpret VS's strict method of passing arguments might be helpful, as a lot of my learning about how to get this working involved my manually calling ML.exe, LINK.exe, etc from the command prompt. Below are several links that may prove useful in answering my question. Please keep in mind that I have read them all and none are the actual solution. I can only hope my specifying MASM 6.11 doesn't prevent anyone from contributing a perhaps more generalized answer. Similar method used to Option (2), but users on the thread are not contactable: http://www.codeguru.com/forum/archive/index.php/t-284051.html (also, I have my doubts about the necessity of an intermediary batch file) Out of date explanation to my question: http://www.cs.fiu.edu/~downeyt/cop3402/masmaul.html Probably the closest thing I've come to a definitive solution, but refers to a suite of tools from something besides MASM, also uses a batch file: http://www.kipirvine.com/asm/gettingStarted/index.htm#16-bit I apologize if my terminology for the tools used in each step of the code - exe process is off, but since I'm trying to reproduce the entirety of steps in between completion of writing the code and generating an executable, I don't think it matters much.

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