Search Results

Search found 3797 results on 152 pages for 'talk'.

Page 26/152 | < Previous Page | 22 23 24 25 26 27 28 29 30 31 32 33  | Next Page >

  • The Hot-Add Memory Hogs

    - by Andrew Clarke
    One of the more difficult tasks, when virtualizing a server, is to determine the amount of memory that Hypervisor should assign to the virtual machine. This requires accurate monitoring and, because of the consequences of setting the value too low, there is a great temptation to err on the side of over-provisioning. This results in fewer guest VMs and, in fact, with more accurate memory provisioning, many virtual environments could support 30% more VMs. In order to achieve a better consolidation (aka VM density) ratio, Windows Server 2008 R2 SP1 has introduced what Microsoft calls ‘Dynamic Memory’. This means that the start-up RAM VM memory assigned to guest virtual machines can be allowed to vary according to demand, changing dynamically while the VM is running, based on the workload of applications running inside. If demand outstrips supply, then memory can be rationed according to the ‘memory weight’ assigned to the guest VM. By this mechanism, memory becomes a shared resource that can be reallocated automatically as demand patterns vary. Unlike VMWare’s Memory Overcommit technology, the sum of all the memory allocations to each virtual machine will not exceed the total memory of the host computer. This is fine for applications that are self-regulating in their demands for memory, releasing memory back into the 'pool' when not under peak load. Other applications however, such as SQL Server Standard and Enterprise, are by nature, memory hogs under high workload; they can grab hot-add memory whilst running under load and then never release it. This requires more careful setting-up and the SQLOS team have provided some guidelines from for configuring SQL Server in virtual environments. Whereas VMWare’s Memory Overcommit is well-proven in a number of different configurations, Hyper-V’s ‘Dynamic Memory’ is new. So far, the indications are that it will improve the business case for virtualizing and it is probably a far more intuitive technology for the average IT professional to grasp. It is certainly worth testing to see whether it works for you.

    Read the article

  • SharePoint Web Part Constructor Fires Twice When Adding it to the Page (and has a different security

    - by Damon
    We had some exciting times debugging an interesting issue with SharePoint 2007 Web Parts.  We had some code in staging that had been running just fine for weeks and had not been touched or changed in about the same amount of time.  However, when we tried to move the web part into a different staging environment, the part started throwing a security exception when we tried to add it to a page.  After a bit of debugging, we determined that the web part was throwing the exception while trying to access the SPGroups property on the SharePoint site.  This was pretty strange because we were logged in as an admin and the code was working perfectly fine before.  During the debugging process, however, we found out that the web part constructor was being fired twice.  On one request, the security context did not seem to have everything it needed in order to run.  On the other request, the security context was populated with the user context with the user making the request (like it normally is).  Moving the security code outside of the constructor seems to have fixed the issue. Why the discrepancy between the two staging environments?  Turns out we deployed the part originally, then deployed an update with the security code.  Since the part was never "added" to the page after the code updates were made (we just deployed a new assembly to make the updates), we never saw the problem.  It seems as though the constructor fires twice when you are adding the web part to the page, and when you run the web part from the web part gallery.  My only thought on why this would occur is that SharePoint is instantiating an instance to get some information from it - which is odd because you would think that would happen with reflection without requiring a new object.  Anyway, the work around is to just not put anything security related inside the constructor, or to do a good job accounting for the possibility of the security context not being present if you are adding the item to the page. Technorati Tags: SharePoint,.NET,Microsoft,ASP.NET

    Read the article

  • Windows Phone 8, possible tablets and what the latest update might mean

    - by Roger Hart
    Microsoft have just announced an update to Windows Phone 8. As one of the five, maybe six people who actually bought a WP8 handset I found this interesting. Then I read the blog post about it, and rushed off to write somewhat less than a thousand words about a single picture. The blog post announces an extra column of tiles on the start screen, and support for higher resolutions. If we ignore all the usual flummery about how this will make your life better, that (and the rotation lock) sounds a little like stage setting for tablets. Looking at the preview screenshot, I started to wonder. What it’s called Phablet_5F00_StartScreenProductivity_5F00_01_5F00_072A1240.jpg Pretty conclusive. If you can brand something a “phablet” and sleep at night you’re made of sterner stuff than I am, but that’s beside the point. It’s explicit in the post that Microsoft are expecting a broader range of form factors for WP8, but they stop short of quite calling out tablet size. The extra columns and resolution definitely back that up, so why stop at a 6 inch “phablet”? Sadly, the string of numbers there don’t really look like a Lumia model number – that would be a bit tendentious even for a speculative blog post about a single screenshot. “Productivity” is interesting too. I get into this a bit more below, but this is a pretty clear pitch for a business device. What it looks like Something that would look quite decent on a 7 inch screen, but something a bit too vertical to go toe-to-toe with the Surface. Certainly, it would look a lot better on a large-factor phone than any of the current models. Those tiles are going to get cramped and a bit ugly if the handsets aren’t getting bigger. What’s on it You have a bunch of missed calls, you rarely text, use a stocks app, and your budget spreadsheet and meeting notes are a thumb-reach away. Outlook is your main form of email. You care enough about LinkedIn to not only install its app but give it a huge live tile. There’s no beating about the bush here, the implicit persona is a corporate exec. With Nokia in the bag and Blackberry pushing daisies, that may not be a stupid play. There’s almost certainly a niche there if they can parlay their corporate credentials into filling it before BYOD (which functionally means an iPhone) reaches the late adopters. The really quite slick WP8 Office implementation ought to help here. This is the face they’ve chosen to present, the cultural milieu they’re normalizing for Windows Phone. It’s an iPhone for Serious Business Grown-ups. Could work, I guess. Does it mean anything? Is the latest WP8 update a sign that we can expect to see tablets running Windows Phone rather than WinRT? Well, WinRT tablets haven’t exactly taken off but I’m not quite going to make a leap like that just from a file name and a column of icons. I feel pretty safe, however, conjecturing that Microsoft would like to squeeze a WP8 “phablet” into the palm of every exec who’s ever grumbled about their Blackberry, and this release might get them a bit closer. If it works well incrementing up to larger devices, then that could be a fair hedge against WinRt crashing and burning any harder in the marketplace.

    Read the article

  • An update process that is even worse than Windows updates

    - by fatherjack
    I'm sorry EA but your game update process stinks. I am not a hardcore gamer but I own a Playstation3 and have been playing Battlefield Bad Company 2 (BFBC2) a bit since I got it for my birthday and there have been two recent updates to the game. Now I like the idea of games getting updates via downloadable content. You can buy a game and if there are changes that are needed (service packs if you will) then they can be distributed over the games console network. Great. Sometimes it fixes problems,...(read more)

    Read the article

  • Automated Error Reporting in .NET Reflector - harnessing the most powerful test rig in existence

    - by Alex.Davies
    I know a testing system that will find more bugs than all the unit testing, integration testing, and QA you could possibly do. And the chances are you're not using it. It's called your users. It's a cliché that you should test so that you find your bugs rather than your users. Of course you should. But it's also a cliché that no software is ever shipped bug-free. Lost cause? No, opportunity! I think .NET Reflector 6 is pretty stable. In fact I know exactly how stable it is, because some (surprisingly high) proportion of its users tell me every time it crashes: If they press "Send Error Report", I get: And then I fix it. As a rough guess, while a standard stack trace is enough to fix a problem 30% of the time, having all those local variables in the stack trace means I can fix it about 80% of the time. How does this all happen? Did it take ages to code this swish system? Nope, it was one checkbox in SmartAssembly. It adds some clever code to your assembly to capture local variables every time an exception is thrown, and to ask your user to report it to you, with a variety of other useful information. Of course not all bugs show up as exceptions. But if you get used to knowing that SmartAssembly will tell you when an exception happens, you begin to change your coding style. Now, as long as an exception gets thrown in any situation you don't expect, you'll fix it if it ever happens. You'll start throwing exceptions liberally, and stop having to think about whether tiny edge cases are possible, as long as they throw an exception if they happen.

    Read the article

  • SQL Server CTE Basics

    The CTE was introduced into standard SQL in order to simplify various classes of SQL Queries for which a derived table just wasn't suitable. For some reason, it can be difficult to grasp the techniques of using it. Well, that's before Rob Sheldon explained it all so clearly for us.

    Read the article

  • A better way to do concurrent programming

    - by Alex.Davies
    Programming to take advantage of multicore processors is hard. If you let multiple threads access the same memory, bad things happen. To avoid this, you use the lock keyword, but if you use that in the wrong way, your code deadlocks. It's all a nightmare. Luckily, there's a better way - Actors. They're really easy to think about. They're really safe (if you follow a couple of simple rules). And high-performance, type-safe actors are now available for .NET by using this open-source library: http://code.google.com/p/n-act/ Have a look at the site for details. I'll blog with more reasons to use actors and tips and tricks to get the best parallelism from them soon.

    Read the article

  • Hands-on Entity Framework

    People keep saying that Entity Framework is simple to learn. Simple? Well, finally, we're going to be forced to agree, thanks to James Johnson's new series on learning EF the hands-on way.

    Read the article

  • Subterranean IL: Custom modifiers

    - by Simon Cooper
    In IL, volatile is an instruction prefix used to set a memory barrier at that instruction. However, in C#, volatile is applied to a field to indicate that all accesses on that field should be prefixed with volatile. As I mentioned in my previous post, this means that the field definition needs to store this information somehow, as such a field could be accessed from another assembly. However, IL does not have a concept of a 'volatile field'. How is this information stored? Attributes The standard way of solving this is to apply a VolatileAttribute or similar to the field; this extra metadata notifies the C# compiler that all loads and stores to that field should use the volatile prefix. However, there is a problem with this approach, namely, the .NET C++ compiler. C++ allows methods to be overloaded using properties, like volatile or const, on the parameters; this is perfectly legal C++: public ref class VolatileMethods { void Method(int *i) {} void Method(volatile int *i) {} } If volatile was specified using a custom attribute, then the VolatileMethods class wouldn't be compilable to IL, as there is nothing to differentiate the two methods from each other. This is where custom modifiers come in. Custom modifiers Custom modifiers are similar to custom attributes, but instead of being applied to an IL element separately to its declaration, they are embedded within the field or parameter's type signature itself. The VolatileMethods class would be compiled to the following IL: .class public VolatileMethods { .method public instance void Method(int32* i) {} .method public instance void Method( int32 modreq( [mscorlib]System.Runtime.CompilerServices.IsVolatile)* i) {} } The modreq([mscorlib]System.Runtime.CompilerServices.IsVolatile) is the custom modifier. This adds a TypeDef or TypeRef token to the signature of the field or parameter, and even though they are mostly ignored by the CLR when it's executing the program, this allows methods and fields to be overloaded in ways that wouldn't be allowed using attributes. Because the modifiers are part of the signature, they need to be fully specified when calling such a method in IL: call instance void Method( int32 modreq([mscorlib]System.Runtime.CompilerServices.IsVolatile)*) There are two ways of applying modifiers; modreq specifies required modifiers (like IsVolatile), and modopt specifies optional modifiers that can be ignored by compilers (like IsLong or IsConst). The type specified as the modifier argument are simple placeholders; if you have a look at the definitions of IsVolatile and IsLong they are completely empty. They exist solely to be referenced by a modifier. Custom modifiers are used extensively by the C++ compiler to specify concepts that aren't expressible in IL, but still need to be taken into account when calling method overloads. C++ and C# That's all very well and good, but how does this affect C#? Well, the C++ compiler uses modreq(IsVolatile) to specify volatility on both method parameters and fields, as it would be slightly odd to have the same concept represented using a modifier or attribute depending on what it was applied to. Once you've compiled your C++ project, it can then be referenced and used from C#, so the C# compiler has to recognise the modreq(IsVolatile) custom modifier applied to fields, and vice versa. So, even though you can't overload fields or parameters with volatile using C#, volatile needs to be expressed using a custom modifier rather than an attribute to guarentee correct interoperability and behaviour with any C++ dlls that happen to come along. Next up: a closer look at attributes, and how certain attributes compile in unexpected ways.

    Read the article

  • DAC pack up all your troubles

    - by Tony Davis
    Visual Studio 2010, or perhaps its apparently-forthcoming sister, "SQL Studio", is being geared up to become the natural way for developers to create databases. Central to this drive is the introduction of 'data-tier application components', or DACs. Applications are developed as normal but when it comes to deployment, instead of supplying the DBA with a bunch of scripts to create the required database objects, the developer creates a single DAC Package ("DAC Pack"); a zipped XML file containing all the database objects needed by the application, along with versioning information, policies for deployment, and so on. It's an intriguing prospect. Developers can work on their development database using their existing tools and source control, and then package up the changes into a single DACPAC for deployment and management. DBAs get an "application level view" of how their instances are being used and the ability to collectively, rather than individually, manage the objects. The DBA needing to manage a large number of relatively small databases can use "DAC snapshots" to get a quick overview of what has changed across all the databases they manage. The reason that DAC packs haven't caused more excitement is that they can only be pushed to SQL Server 2008 R2, and they must be developed or inspected using Visual Studio 2010. Furthermore, what we see right now in VS2010 is more of a 'work-in-progress' or 'vision of the future', with serious shortcomings and restrictions that render it unsuitable for anything but small 'non-critical' departmental databases. The first problem is that DAC packs support a limited set of schema objects (corresponding closely to the features available on 'Azure'). This means that Service Broker queues, CLR Objects, and perhaps most critically security (permissions, certificates etc.), are off-limits. Applications that require these objects will need to add them via a post-deployment TSQL script, rather defeating the whole idea. More worrying still is the process for altering a database with a DAC pack. The grand 'collective' philosophy, whereby a single XML file can be used for deploying and managing builds and changes, extends, unfortunately, to database upgrades. Any change to a database object will result in the creation of a new database, copying the data from the old version, nuking the previous one, and then renaming the new one. Simple eh? The problem is that even something as trivial as adding a comment to a stored procedure in a 5GB database will require the server to find at least twice as much space, as well sufficient elbow-room in the transaction log for copying the largest table. Of course, you'll need to take the database offline for the full course of the deployment, which is likely to take a long time if there is a lot of data. This upgrade/rename process breaks the log chain, makes any subsequent full restore operation highly complicated, and will also break log shipping. As with any grand vision, the devil is always in the detail. It's hard to fathom why Microsoft hasn't used a SQL Compare-style approach to the upgrade process, altering a database with a change script, and this will surely be adopted in the near future. Something had to be in place for VS2010, but right now DAC packs only make sense for Azure. For this, they're cute, but hardly compelling. Nevertheless, DBAs would do well to get familiar with VS 2010 and DAC packs. Like it or not, they're both coming. Cheers, Tony.

    Read the article

  • Who writes the words? A rant with graphs.

    - by Roger Hart
    If you read my rant, you'll know that I'm getting a bit of a bee in my bonnet about user interface text. But rather than just yelling about the way the world should be (short version: no UI text would suck), it seemed prudent to actually gather some data. Rachel Potts has made an excellent first foray, by conducting a series of interviews across organizations about how they write user interface text. You can read Rachel's write up here. She presents the facts as she found them, and doesn't editorialise. The result is insightful, but impartial isn't really my style. So here's a rant with graphs. My method, and how it sucked I sent out a short survey. Survey design is one of my hobby-horses, and since some smartarse in the comments will mention it if I don't, I'll step up and confess: I did not design this one well. It was potentially ambiguous, implicitly excluded people, and since I only really advertised it on Twitter and a couple of mailing lists the sample will be chock full of biases. Regardless, these were the questions: What do you do? Select the option that best describes your role What kind of software does your organization make? (optional) In your organization, who writes the text on your software user interfaces? (for example: button names, static text, tooltips, and so on) Tick all that apply. In your organization who is responsible for user interface text? Who "owns" it? The most glaring issue (apart from question 3 being a bit broken) was that I didn't make it clear that I was asking about applications. Desktop, mobile, or web, I wouldn't have minded. In fact, it might have been interesting to categorize and compare. But a few respondents commented on the seeming lack of relevance, since they didn't really make software. There were some other issues too. It wasn't the best survey. So, you know, pinch of salt time with what follows. Despite this, there were 100 or so respondents. This post covers the overview, and you can look at the raw data in this spreadsheet What did people do? Boring graph number one: I wasn't expecting that. Given I pimped the survey on twitter and a couple of Tech Comms discussion lists, I was more banking on and even Content Strategy/Tech Comms split. What the "Others" specified: Three people chipped in with Technical Writer. Author, apparently, doesn't cut it. There's a "nobody reads the instructions" joke in there somewhere, I'm sure. There were a couple of hybrid roles, including Tech Comms and Testing, which sounds gruelling and thankless. There was also, an Intranet Manager, a Creative Director, a Consultant, a CTO, an Information Architect, and a Translator. That's a pretty healthy slice through the industry. Who wrote UI text? Boring graph number two: Annoyingly, I made this a "tick all that apply" question, so I can't make crude and inflammatory generalizations about percentages. This is more about who gets involved in user interface wording. So don't panic about the number of developers writing UI text. First off, it just means they're involved. Second, they might be good at it. What? It could happen. Ours are involved - they write a placeholder and flag it to me for changes. Sometimes I don't make any. It's also not surprising that there's so much UX in the mix. Some of that will be people taking care, and crafting an understandable interface. Some of it will be whatever text goes on the wireframe making it into production. I'm going to assume that's what happened at eBay, when their iPhone app purportedly shipped with the placeholder text "Some crappy content goes here". Ahem. Listing all 17 "other" responses would make this post lengthy indeed, but you can read them in the raw data spreadsheet. The award for the approach that sounds the most like a good idea yet carries the highest risk of ending badly goes to whoever offered up "External agencies using focus groups". If you're reading this, and that actually works, leave a comment. I'm fascinated. Who owned UI text Stop. Bar chart time: Wow. Let's cut to the chase, and by "chase", I mean those inflammatory generalizations I was talking about: In around 60% of cases the person responsible for user interface text probably lacks the relevant expertise. Even in the categories I count as being likely to have relevant skills (Marketing Copywriters, Content Strategists, Technical Authors, and User Experience Designers) there's a case for each role being unsuited, as you'll see in Rachel's blog post So it's not as simple as my headline. Does that mean that you personally, Mr Developer reading this, write bad button names? Of course not. I know nothing about you. It rather implies that as a category, the majority of people looking after UI text have neither communication nor user experience as their primary skill set, and as such will probably only be good at this by happy accident. I don't have a way of measuring those frequency of those accidents. What the Others specified: I don't know who owns it. I assume the project manager is responsible. "copywriters" when they wish to annoy me. the client's web maintenance person, often PR or MarComm That last one chills me to the bone. Still, at least nobody said "the work experience kid". You can see the rest in the spreadsheet. My overwhelming impression here is of user interface text as an unloved afterthought. There were fewer "nobody" responses than I expected, and a much broader split. But the relative predominance of developers owning and writing UI text suggests to me that organizations don't see it as something worth dedicating attention to. If true, that's bothersome. Because the words on the screen, particularly the names of things, are fundamental to the ability to understand an use software. It's also fascinating that Technical Authors and Content Strategists are neck and neck. For such a nascent discipline, Content Strategy appears to have made a mark on software development. Or my sample is skewed. But it feels like a bit of validation for my rant: Content Strategy is eating Tech Comms' lunch. That's not a bad thing. Well, not if the UI text is getting done well. And that's the caveat to this whole post. I couldn't care less who writes UI text, provided they consider the user and don't suck at it. I care that it may be falling by default to people poorly disposed to doing it right. And I care about that because so much user interface text sucks. The most interesting question Was one I forgot to ask. It's this: Does your organization have technical authors/writers? Like a lot of survey data, that doesn't tell you much on its own. But once we get a bit dimensional, it become more interesting. So taken with the other questions, this would have let me find out what I really want to know: What proportion of organizations have Tech Comms professionals but don't use them for UI text? Who writes UI text in their place? Why this happens? It's possible (feasible is another matter) that hundreds of companies have tech authors who don't work on user interfaces because they've empirically discovered that someone else, say the Marketing Copywriter, is better at it. And once we've all finished laughing, I'll point out that I've met plenty of tech authors who just aren't used to thinking about users at the point of need in the way UI text and embedded user assistance require. If you've got what I regard, perhaps unfairly, as the bad kind of tech author - the old-school kind with the thousand-page pdf and the grammar obsession - if you've got one of those then you probably are better off getting the UX folk or the copywriters to do your UI text. At the very least, they'll derive terminology from user research.

    Read the article

  • IndyTechFest Recap

    - by Johnm
    The sun had yet to raise above the horizon on Saturday, May 22nd and I was traveling toward the location of the 2010 IndyTechFest. In my freshly awaken, and pre-coffee, state I reflected on the months that preceded this day and how quickly they slipped away. The big day had finally come and the morning dew glistened with a unique brightness that morning. What is this all about? For those who are unfamiliar with IndyTechFest, it is a regional conference held in Indianapolis and hosted by the Indianapolis .NET Developers Association (IndyNDA) and the Indianapolis Professional Association for SQL Server (IndyPASS).  The event presents multiple tracks and sessions covering subjects such as Business Intelligence,  Database Administration, .NET Development, SharePoint Development, Windows Mobile Development as well as non-Microsoft topics such as Lean and MongoDB. This year's event was the third hosting of IndyTechFest. No man is an island No event such as IndyTechFest is executed by a single person. My fellow co-founders, with their highly complementary skill sets and philanthropy make the process very enjoyable. Our amazing volunteers and their aid were indispensible. The generous financial support of our sponsors that made the event and fabulous prizes possible. The spectacular line up of speakers who came from near and far to donate their time and knowledge. Our beloved attendees who sacrificed the first sunny Saturday in weeks to expand their skill sets and network with their peers. We are deeply appreciative. Challenges in preparation With the preparation of any event comes challenges. It is these challenges that makes the process of planning an event so interesting. This year's largest challenge was the location of the event. In the past two years IndyTechFest was held at the Gene B. Glick Junior Achievement Center in Indianapolis. This facility has been the hub of the Indy technical community for many years. As the big day drew near, the facility's availability came into question due to some recent changes that had occurred with those who operated the facility. We began our search for an alternative option. Thankfully, the Marriott Indianapolis East was available, was very spacious and willing to work within the range of our budget. Within days of our event, the decision to move proved to be wise since the prior location had begun renovations to the interior. Whew! Always trust your gut. Every day it's getting better At the ending of each year, we huddle together, review the evaluations and identify an area in which the event could improve. This year's big opportunity for improvement resided in the prize give-away portion at the end of the day. In the 2008 event, admittedly, this portion was rather chaotic, rushed and disorganized. This year, we broke the drawing into two sections, of which each attendee received two tickets. The first ticket was a drawing for the mountain of books that were given away. The second ticket was a drawing for the big prizes, the 2 Xboxes, 3 laptops and iPad. We peppered the ticket drawings with gift card raffles and tossing t-shirts into the audience. If at first you don't succeed, try and try again Each year of IndyTechFest, we have offered a means for ad-hoc sessions or discussion groups to pop-up. To our disappointment it was something that never quite took off. We have always believed that this unique type of session was valuable and wanted to figure out a way to make it work for this year. A special thanks to Alan Stevens, who took on and facilitated the "open space" track and made it an official success. Share with your tweety When the attendee badges were designed we decided to place an emphasis on the attendee's Twitter account as well as the events hash-tag (#IndyTechFest) to encourage some real-time buzz during the day. At the host table we displayed a Twitter feed for all to enjoy. It was quite successful and encouraging use of social media. My badge was missing my Twitter account since it was recently changed. For those who care to follow my rather sparse tweets, my address is @johnnydata. Man, this is one long blog post! All in all it was a very successful event. It is always great to see new faces and meet old friends. The planning for the 2011 IndyTechFest will kick off very soon. We have more capacity for future growth and a truck full of great ideas. Stay tuned!

    Read the article

  • Alan Turing Needs Your Help

    - by Chris Massey
    Well. sort of. Clearly, you are using a computer. If you are on this site, you are probably quite familiar with computers as artifacts of our modern society. Hopefully, you are also familiar with the fact that Alan Turing, logician and mathematician extraordinaire, was instrumental in laying down the foundations of modern computer science, and did a little work to help turn the tide of WWII in the Allies' favor. Hold that thought. A phenomenal collection of Turing's papers (including his first ever...(read more)

    Read the article

  • Anatomy of a .NET Assembly - Signature encodings

    - by Simon Cooper
    If you've just joined this series, I highly recommend you read the previous posts in this series, starting here, or at least these posts, covering the CLR metadata tables. Before we look at custom attribute encoding, we first need to have a brief look at how signatures are encoded in an assembly in general. Signature types There are several types of signatures in an assembly, all of which share a common base representation, and are all stored as binary blobs in the #Blob heap, referenced by an offset from various metadata tables. The types of signatures are: Method definition and method reference signatures. Field signatures Property signatures Method local variables. These are referenced from the StandAloneSig table, which is then referenced by method body headers. Generic type specifications. These represent a particular instantiation of a generic type. Generic method specifications. Similarly, these represent a particular instantiation of a generic method. All these signatures share the same underlying mechanism to represent a type Representing a type All metadata signatures are based around the ELEMENT_TYPE structure. This assigns a number to each 'built-in' type in the framework; for example, Uint16 is 0x07, String is 0x0e, and Object is 0x1c. Byte codes are also used to indicate SzArrays, multi-dimensional arrays, custom types, and generic type and method variables. However, these require some further information. Firstly, custom types (ie not one of the built-in types). These require you to specify the 4-byte TypeDefOrRef coded token after the CLASS (0x12) or VALUETYPE (0x11) element type. This 4-byte value is stored in a compressed format before being written out to disk (for more excruciating details, you can refer to the CLI specification). SzArrays simply have the array item type after the SZARRAY byte (0x1d). Multidimensional arrays follow the ARRAY element type with a series of compressed integers indicating the number of dimensions, and the size and lower bound of each dimension. Generic variables are simply followed by the index of the generic variable they refer to. There are other additions as well, for example, a specific byte value indicates a method parameter passed by reference (BYREF), and other values indicating custom modifiers. Some examples... To demonstrate, here's a few examples and what the resulting blobs in the #Blob heap will look like. Each name in capitals corresponds to a particular byte value in the ELEMENT_TYPE or CALLCONV structure, and coded tokens to custom types are represented by the type name in curly brackets. A simple field: int intField; FIELD I4 A field of an array of a generic type parameter (assuming T is the first generic parameter of the containing type): T[] genArrayField FIELD SZARRAY VAR 0 An instance method signature (note how the number of parameters does not include the return type): instance string MyMethod(MyType, int&, bool[][]); HASTHIS DEFAULT 3 STRING CLASS {MyType} BYREF I4 SZARRAY SZARRAY BOOLEAN A generic type instantiation: MyGenericType<MyType, MyStruct> GENERICINST CLASS {MyGenericType} 2 CLASS {MyType} VALUETYPE {MyStruct} For more complicated examples, in the following C# type declaration: GenericType<T> : GenericBaseType<object[], T, GenericType<T>> { ... } the Extends field of the TypeDef for GenericType will point to a TypeSpec with the following blob: GENERICINST CLASS {GenericBaseType} 3 SZARRAY OBJECT VAR 0 GENERICINST CLASS {GenericType} 1 VAR 0 And a static generic method signature (generic parameters on types are referenced using VAR, generic parameters on methods using MVAR): TResult[] GenericMethod<TInput, TResult>( TInput, System.Converter<TInput, TOutput>); GENERIC 2 2 SZARRAY MVAR 1 MVAR 0 GENERICINST CLASS {System.Converter} 2 MVAR 0 MVAR 1 As you can see, complicated signatures are recursively built up out of quite simple building blocks to represent all the possible variations in a .NET assembly. Now we've looked at the basics of normal method signatures, in my next post I'll look at custom attribute application signatures, and how they are different to normal signatures.

    Read the article

  • Subterranean IL: Exception handler semantics

    - by Simon Cooper
    In my blog posts on fault and filter exception handlers, I said that the same behaviour could be replicated using normal catch blocks. Well, that isn't entirely true... Changing the handler semantics Consider the following: .try { .try { .try { newobj instance void [mscorlib]System.Exception::.ctor() // IL for: // e.Data.Add("DictKey", true) throw } fault { ldstr "1: Fault handler" call void [mscorlib]System.Console::WriteLine(string) endfault } } filter { ldstr "2a: Filter logic" call void [mscorlib]System.Console::WriteLine(string) // IL for: // (bool)((Exception)e).Data["DictKey"] endfilter }{ ldstr "2b: Filter handler" call void [mscorlib]System.Console::WriteLine(string) leave.s Return } } catch object { ldstr "3: Catch handler" call void [mscorlib]System.Console::WriteLine(string) leave.s Return } Return: // rest of method If the filter handler is engaged (true is inserted into the exception dictionary) then the filter handler gets engaged, and the following gets printed to the console: 2a: Filter logic 1: Fault handler 2b: Filter handler and if the filter handler isn't engaged, then the following is printed: 2a:Filter logic 1: Fault handler 3: Catch handler Filter handler execution The filter handler is executed first. Hmm, ok. Well, what happens if we replaced the fault block with the C# equivalent (with the exception dictionary value set to false)? .try { // throw exception } catch object { ldstr "1: Fault handler" call void [mscorlib]System.Console::WriteLine(string) rethrow } we get this: 1: Fault handler 2a: Filter logic 3: Catch handler The fault handler is executed first, instead of the filter block. Eh? This change in behaviour is due to the way the CLR searches for exception handlers. When an exception is thrown, the CLR stops execution of the thread, and searches up the stack for an exception handler that can handle the exception and stop it propagating further - catch or filter handlers. It checks the type clause of catch clauses, and executes the code in filter blocks to see if the filter can handle the exception. When the CLR finds a valid handler, it saves the handler's location, then goes back to where the exception was thrown and executes fault and finally blocks between there and the handler location, discarding stack frames in the process, until it reaches the handler. So? By replacing a fault with a catch, we have changed the semantics of when the filter code is executed; by using a rethrow instruction, we've split up the exception handler search into two - one search to find the first catch, then a second when the rethrow instruction is encountered. This is only really obvious when mixing C# exception handlers with fault or filter handlers, so this doesn't affect code written only in C#. However it could cause some subtle and hard-to-debug effects with object initialization and ordering when using and calling code written in a language that can compile fault and filter handlers.

    Read the article

  • Adding Actions to a Cube in SQL Server Analysis Services 2008

    Actions are powerful way of extending the value of SSAS cubes for the end user. They can click on a cube or portion of a cube to start an application with the selected item as a parameter, or to retrieve information about the selected item. Actions haven't been well-documented until now; Robert Sheldon once more makes everything clear.

    Read the article

  • From WinForm to WPF: A Quick Reference Guide

    Michael Sorens provides a handy wallchart to help migration between WinForm / WPF, VS 2008 / 2010, and .NET 3.5 / 4.0. this can be downloaded for free from the speech-bubble at the head of the article. He also describes the current weaknesses in WPF, and the most obvious differences between the two.

    Read the article

  • Reflector Pro has now been released!

    - by CliveT
    After moving into the .NET division in May , and having a great time working on Reflector, I'm pleased to say that the results of that work are now available. Reflector Pro has now been released! The old Reflector as you know and love it is still available free of charge, and as part of this project we've fixed a number of bugs in the de-compilation that have been around for a long time. The Pro version comes as an add-in for Visual Studio - this offers dynamic de-compilation and generation of pdb files which allow you to step into the de-compiled code. Alex has some good pictures of this functionality on his beta post from around a month ago. Thanks to the other guys who've worked on this for taking me along for the ride - Alex, Andrew, Bart and Jason. Stephen did some great usability work, Chris Alford did some great technical authoring and Laila handled the launch publicity. Like all projects, there's always more I'd like to have done, but what we have looks like a pretty powerful addition to the developer's set of tools to me. Please try it and give us feedback on the forum.

    Read the article

  • Subterranean IL: Fault exception handlers

    - by Simon Cooper
    Fault event handlers are one of the two handler types that aren't available in C#. It behaves exactly like a finally, except it is only run if control flow exits the block due to an exception being thrown. As an example, take the following method: .method public static void FaultExample(bool throwException) { .try { ldstr "Entering try block" call void [mscorlib]System.Console::WriteLine(string) ldarg.0 brfalse.s NormalReturn ThrowException: ldstr "Throwing exception" call void [mscorlib]System.Console::WriteLine(string) newobj void [mscorlib]System.Exception::.ctor() throw NormalReturn: ldstr "Leaving try block" call void [mscorlib]System.Console::WriteLine(string) leave.s Return } fault { ldstr "Fault handler" call void [mscorlib]System.Console::WriteLine(string) endfault } Return: ldstr "Returning from method" call void [mscorlib]System.Console::WriteLine(string) ret } If we pass true to this method the following gets printed: Entering try block Throwing exception Fault handler and the exception gets passed up the call stack. So, the exception gets thrown, the fault handler gets run, and the exception propagates up the stack afterwards in the normal way. If we pass false, we get the following: Entering try block Leaving try block Returning from method Because we are leaving the .try using a leave.s instruction, and not throwing an exception, the fault handler does not get called. Fault handlers and C# So why were these not included in C#? It seems a pretty simple feature; one extra keyword that compiles in exactly the same way, and with the same semantics, as a finally handler. If you think about it, the same behaviour can be replicated using a normal catch block: try { throw new Exception(); } catch { // fault code goes here throw; } The catch block only gets run if an exception is thrown, and the exception gets rethrown and propagates up the call stack afterwards; exactly like a fault block. The only complications that occur is when you want to add a fault handler to a try block with existing catch handlers. Then, you either have to wrap the try in another try: try { try { // ... } catch (DirectoryNotFoundException) { // ... // leave.s as normal... } catch (IOException) { // ... throw; } } catch { // fault logic throw; } or separate out the fault logic into another method and call that from the appropriate handlers: try { // ... } catch (DirectoryNotFoundException ) { // ... } catch (IOException ioe) { // ... HandleFaultLogic(); throw; } catch (Exception e) { HandleFaultLogic(); throw; } To be fair, the number of times that I would have found a fault handler useful is minimal. Still, it's quite annoying knowing such functionality exists, but you're not able to access it from C#. Fortunately, there are some easy workarounds one can use instead. Next time: filter handlers.

    Read the article

  • Setting the Default Wiki Page in a SharePoint Wiki Library

    - by Damon Armstrong
    I’ve seen a number of blog posts about setting the default homepage in a wiki library, and most of them offer ways of accomplishing this task through PowerShell or through SharePoint designer.  Although I have become an ever increasing fan of PowerShell, I still prefer to stay away from it unless I’m trying to do something fairly complicated or I need a script that I can run over and over again.  If all you need to do is set the default homepage in a wiki library, there is an easier way! First, navigate to the wiki page you want to use as the default homepage.  Then click the Page tab in the ribbon.  In the Page Actions group there is a button called Make Homepage.  Click it.  A confirmation displays informing you that you are about to change the homepage.  Click OK and you will have a new homepage for your wiki library.  No PowerShell required.

    Read the article

  • If unexpected database changes cause you problems – we can help!

    - by Chris Smith
    Have you ever been surprised by an unexpected difference between you database environments? Have you ever found that your Staging database is not the same as your Production database, even though it was the week before? Has an emergency hotfix suddenly appeared in Production over the weekend without your knowledge? Has your client secretly added a couple of indices to their local version of the database to aid performance? Worse still, has a developer ever accidently run a SQL script against the wrong database without noticing their mistake? If you’ve answered “Yes” to any of the above questions then you’ve suffered from ‘drift’. Database drift is where the state of a database (schema, particularly) has moved away from its expected or official state over time. The upshot is that the database is in an unknown or poorly-understood state. Even if these unexpected changes are not destructive, drift can be a big problem when it’s time to release a new version of the database. A deployment to a target database in an unexpected state can error and fail, potentially delaying a vital, time-sensitive update. A big issue with drift is that it can be hard to spot and it can be even harder to determine its provenance. So, before you can deal with an issue caused by drift, you’ll need to know exactly what change has been made, who made it, when they made it and why they made it. Those questions can take a lot of effort to answer. Then you actually need to decide what to do. Do you rollback the change because it was bad? Retrospectively apply it to the Staging environment because it is a required change? Or script the change into version control to get it back in line with your process? Red Gate’s Database Delivery Team have been talking to DBAs, database consultants and database developers to explore the problem of drift. We’ve started to get a really good idea of how big a problem it can be and what database professionals need to know and do, in order to deal with it.  It’s fair to say, we’re pretty excited at the prospect of creating a tool that will really help and we’ve got some great feedback on our initial ideas (see image below).   We’re now well underway with the development of our new drift-spotting product – SQL Lighthouse – and we hope to have a beta release out towards the end of July. What we really need is your help to shape the product into a great tool. So, if database drift is a problem that you’d like help solving and are interested in finding out more about our product, join our mailing list to register your interest in trying out the beta release. Subscribe to our mailing list

    Read the article

  • What Counts For A DBA: Foresight

    - by drsql
    Of all the valuable attributes of a DBA covered so far in this series, ranging from passion to humility to practicality, perhaps one of the most important attributes may turn out to be the most seemingly-nebulous: foresight. According to Free Dictionary foresight is the "perception of the significance and nature of events before they have occurred". Foresight does not come naturally to most people, as the parent of any teenager will attest. No matter how clearly you see their problems coming they won't listen, and have to fail before eventually (hopefully) learning for themselves. Having graduated from the school of hard knocks, the DBA, the naive teenager no longer, acquires the ability to foretell how events will unfold in response to certain actions or attitudes with the unerring accuracy of a doom-laden prophet. Like Simba in the Lion King, after a few blows to the head, we foretell that a sore head that will be the inevitable consequence of a swing of Rafiki's stick, and we take evasive action. However, foresight is about more than simply learning when to duck. It's about taking the time to understand and prevent the habits that caused the stick to swing in the first place. And based on this definition, I often think there is a lot less foresight on display in my industry than there ought to be. Most DBAs reading this blog will spot a line such as the following in a piece of "working" code, understand immediately why it is less than optimimum, and take evasive action. …WHERE CAST (columnName as int) = 1 However, the programmers who regularly write this sort of code clearly lack that foresight, and this and numerous other examples of similarly-malodorous code prevail throughout our industry (and provide premium-grade fertilizer for the healthy growth of many a consultant's bank account). Sometimes, perhaps harried by impatient managers and painfully tight deadlines, everyone makes mistakes. Yes, I too occasionally write code that "works", but basically stinks. When the problems manifest, it is sometimes accompanied by a sense of grim recognition that somewhere in me existed the foresight to know that that approach would lead to this problem. However, in the headlong rush, warning signs got overlooked, lessons learned previously, which could supply the foresight to the current project, were lost and not applied.   Of course, the problem often is a simple lack of skills, training and knowledge in the relevant technology and/or business space; programmers and DBAs forced to do their best in the face of inadequate training, or to apply their skills in areas where they lack experience. However, often the problem goes deeper than this; I detect in some DBAs and programmers a certain laziness of attitude.   They veer from one project to the next, going with "whatever works", unwilling or unable to take the time to understand where their actions are leading them. Of course, the whole "Agile" mindset is often interpreted to favor flexibility and rapid production over aiming to get things right the first time. The faster you try to travel in the dark, frequently changing direction, the more important it is to have someone who has the foresight to know at least roughly where you are heading. This is doubly true for the data tier which, no matter how you try to deny it, simply cannot be "redone" every month as you learn aspects of the world you are trying to model that, with a little bit of foresight, you would have seen coming.   Sometimes, when as a DBA you can glance briefly at 200 lines of working SQL code and know instinctively why it will cause problems, foresight can feel like magic, but it isn't; it's more like muscle memory. It is acquired as the consequence of good experience, useful communication with those around you, and a willingness to learn continually, through continued education as well as from failure. Foresight can be deployed only by finding time to understand how the lessons learned from other DBAs, and other projects, can help steer the current project in the right direction.   C.S. Lewis once said "The future is something which everyone reaches at the rate of sixty minutes an hour, whatever he does, whoever he is." It cannot be avoided; the quality of what you build now is going to affect you, and others, at some point in the future. Take the time to acquire foresight; it is a love letter to your future self, to say you cared.

    Read the article

  • Hype and LINQ

    - by Tony Davis
    "Tired of querying in antiquated SQL?" I blinked in astonishment when I saw this headline on the LinqPad site. Warming to its theme, the site suggests that what we need is to "kiss goodbye to SSMS", and instead use LINQ, a modern query language! Elsewhere, there is an article entitled "Why LINQ beats SQL". The designers of LINQ, along with many DBAs, would, I'm sure, cringe with embarrassment at the suggestion that LINQ and SQL are, in any sense, competitive ways of doing the same thing. In fact what LINQ really is, at last, is an efficient, declarative language for C# and VB programmers to access or manipulate data in objects, local data stores, ORMs, web services, data repositories, and, yes, even relational databases. The fact is that LINQ is essentially declarative programming in a .NET language, and so in many ways encourages developers into a "SQL-like" mindset, even though they are not directly writing SQL. In place of imperative logic and loops, it uses various expressions, operators and declarative logic to build up an "expression tree" describing only what data is required, not the operations to be performed to get it. This expression tree is then parsed by the language compiler, and the result, when used against a relational database, is a SQL string that, while perhaps not always perfect, is often correctly parameterized and certainly no less "optimal" than what is achieved when a developer applies blunt, imperative logic to the SQL language. From a developer standpoint, it is a mistake to consider LINQ simply as a substitute means of querying SQL Server. The strength of LINQ is that that can be used to access any data source, for which a LINQ provider exists. Microsoft supplies built-in providers to access not just SQL Server, but also XML documents, .NET objects, ADO.NET datasets, and Entity Framework elements. LINQ-to-Objects is particularly interesting in that it allows a declarative means to access and manipulate arrays, collections and so on. Furthermore, as Michael Sorens points out in his excellent article on LINQ, there a whole host of third-party LINQ providers, that offers a simple way to get at data in Excel, Google, Flickr and much more, without having to learn a new interface or language. Of course, the need to be generic enough to deal with a range of data sources, from something as mundane as a text file to as esoteric as a relational database, means that LINQ is a compromise and so has inherent limitations. However, it is a powerful and beautifully compact language and one that, at least in its "query syntax" guise, is accessible to developers and DBAs alike. Perhaps there is still hope that LINQ can fulfill Phil Factor's lobster-induced fantasy of a language that will allow us to "treat all data objects, whether Word files, Excel files, XML, relational databases, text files, HTML files, registry files, LDAPs, Outlook and so on, in the same logical way, as linked databases, and extract the metadata, create the entities and relationships in the same way, and use the same SQL syntax to interrogate, create, read, write and update them." Cheers, Tony.

    Read the article

  • Creating a simple RSS reader using ListView,XMLDatasource,DataPager web server controls

    - by nikolaosk
    In my last ASP.Net seminar someone noticed that we did not talk at all about the XmlDataSource,ListView,DataPager web server controls. It is rather impossible to investigate/talk about all issues regarding ASP.Net in a seminar but I promised to write a blog post. I thought that I could combine all those three web server controls to create a RSS reader. 1) Launch Visual Studio 2008/2010. Express editions will work fine. 2) Create an empty asp.net web site. Choose an appropriate name. We will not write...(read more)

    Read the article

  • Showplan Operator of the Week - Compute Scalar

    The third part of Fabiano's mission to describe the major Showplan Operators used by SQL Server's Query Optimiser continues with the 'Compute Scalar' operator. Fabiano shows how a tweak to SQL to avoid a 'Compute Scalar' step can improve its performance.

    Read the article

< Previous Page | 22 23 24 25 26 27 28 29 30 31 32 33  | Next Page >