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• A way of doing real-world test-driven development (and some thoughts about it)

  - by Thomas Weller

  Lately, I exchanged some arguments with Derick Bailey about some details of the red-green-refactor cycle of the Test-driven development process. In short, the issue revolved around the fact that it’s not enough to have a test red or green, but it’s also important to have it red or green for the right reasons. While for me, it’s sufficient to initially have a NotImplementedException in place, Derick argues that this is not totally correct (see these two posts: Red/Green/Refactor, For The Right Reasons and Red For The Right Reason: Fail By Assertion, Not By Anything Else). And he’s right. But on the other hand, I had no idea how his insights could have any practical consequence for my own individual interpretation of the red-green-refactor cycle (which is not really red-green-refactor, at least not in its pure sense, see the rest of this article). This made me think deeply for some days now. In the end I found out that the ‘right reason’ changes in my understanding depending on what development phase I’m in. To make this clear (at least I hope it becomes clear…) I started to describe my way of working in some detail, and then something strange happened: The scope of the article slightly shifted from focusing ‘only’ on the ‘right reason’ issue to something more general, which you might describe as something like  'Doing real-world TDD in .NET , with massive use of third-party add-ins’. This is because I feel that there is a more general statement about Test-driven development to make:  It’s high time to speak about the ‘How’ of TDD, not always only the ‘Why’. Much has been said about this, and me myself also contributed to that (see here: TDD is not about testing, it's about how we develop software). But always justifying what you do is very unsatisfying in the long run, it is inherently defensive, and it costs time and effort that could be used for better and more important things. And frankly: I’m somewhat sick and tired of repeating time and again that the test-driven way of software development is highly preferable for many reasons - I don’t want to spent my time exclusively on stating the obvious… So, again, let’s say it clearly: TDD is programming, and programming is TDD. Other ways of programming (code-first, sometimes called cowboy-coding) are exceptional and need justification. – I know that there are many people out there who will disagree with this radical statement, and I also know that it’s not a description of the real world but more of a mission statement or something. But nevertheless I’m absolutely sure that in some years this statement will be nothing but a platitude. Side note: Some parts of this post read as if I were paid by Jetbrains (the manufacturer of the ReSharper add-in – R#), but I swear I’m not. Rather I think that Visual Studio is just not production-complete without it, and I wouldn’t even consider to do professional work without having this add-in installed... The three parts of a software component Before I go into some details, I first should describe my understanding of what belongs to a software component (assembly, type, or method) during the production process (i.e. the coding phase). Roughly, I come up with the three parts shown below:   First, we need to have some initial sort of requirement. This can be a multi-page formal document, a vague idea in some programmer’s brain of what might be needed, or anything in between. In either way, there has to be some sort of requirement, be it explicit or not. – At the C# micro-level, the best way that I found to formulate that is to define interfaces for just about everything, even for internal classes, and to provide them with exhaustive xml comments. The next step then is to re-formulate these requirements in an executable form. This is specific to the respective programming language. - For C#/.NET, the Gallio framework (which includes MbUnit) in conjunction with the ReSharper add-in for Visual Studio is my toolset of choice. The third part then finally is the production code itself. It’s development is entirely driven by the requirements and their executable formulation. This is the delivery, the two other parts are ‘only’ there to make its production possible, to give it a decent quality and reliability, and to significantly reduce related costs down the maintenance timeline. So while the first two parts are not really relevant for the customer, they are very important for the developer. The customer (or in Scrum terms: the Product Owner) is not interested at all in how  the product is developed, he is only interested in the fact that it is developed as cost-effective as possible, and that it meets his functional and non-functional requirements. The rest is solely a matter of the developer’s craftsmanship, and this is what I want to talk about during the remainder of this article… An example To demonstrate my way of doing real-world TDD, I decided to show the development of a (very) simple Calculator component. The example is deliberately trivial and silly, as examples always are. I am totally aware of the fact that real life is never that simple, but I only want to show some development principles here… The requirement As already said above, I start with writing down some words on the initial requirement, and I normally use interfaces for that, even for internal classes - the typical question “intf or not” doesn’t even come to mind. I need them for my usual workflow and using them automatically produces high componentized and testable code anyway. To think about their usage in every single situation would slow down the production process unnecessarily. So this is what I begin with: namespace Calculator {     /// <summary>     /// Defines a very simple calculator component for demo purposes.     /// </summary>     public interface ICalculator     {         /// <summary>         /// Gets the result of the last successful operation.         /// </summary>         /// <value>The last result.</value>         /// <remarks>         /// Will be <see langword="null" /> before the first successful operation.         /// </remarks>         double? LastResult { get; }       } // interface ICalculator   } // namespace Calculator So, I’m not beginning with a test, but with a sort of code declaration - and still I insist on being 100% test-driven. There are three important things here: Starting this way gives me a method signature, which allows to use IntelliSense and AutoCompletion and thus eliminates the danger of typos - one of the most regular, annoying, time-consuming, and therefore expensive sources of error in the development process. In my understanding, the interface definition as a whole is more of a readable requirement document and technical documentation than anything else. So this is at least as much about documentation than about coding. The documentation must completely describe the behavior of the documented element. I normally use an IoC container or some sort of self-written provider-like model in my architecture. In either case, I need my components defined via service interfaces anyway. - I will use the LinFu IoC framework here, for no other reason as that is is very simple to use. The ‘Red’ (pt. 1)   First I create a folder for the project’s third-party libraries and put the LinFu.Core dll there. Then I set up a test project (via a Gallio project template), and add references to the Calculator project and the LinFu dll. Finally I’m ready to write the first test, which will look like the following: namespace Calculator.Test {     [TestFixture]     public class CalculatorTest     {         private readonly ServiceContainer container = new ServiceContainer();           [Test]         public void CalculatorLastResultIsInitiallyNull()         {             ICalculator calculator = container.GetService<ICalculator>();               Assert.IsNull(calculator.LastResult);         }       } // class CalculatorTest   } // namespace Calculator.Test       This is basically the executable formulation of what the interface definition states (part of). Side note: There’s one principle of TDD that is just plain wrong in my eyes: I’m talking about the Red is 'does not compile' thing. How could a compiler error ever be interpreted as a valid test outcome? I never understood that, it just makes no sense to me. (Or, in Derick’s terms: this reason is as wrong as a reason ever could be…) A compiler error tells me: Your code is incorrect, but nothing more.  Instead, the ‘Red’ part of the red-green-refactor cycle has a clearly defined meaning to me: It means that the test works as intended and fails only if its assumptions are not met for some reason. Back to our Calculator. When I execute the above test with R#, the Gallio plugin will give me this output: So this tells me that the test is red for the wrong reason: There’s no implementation that the IoC-container could load, of course. So let’s fix that. With R#, this is very easy: First, create an ICalculator - derived type:        Next, implement the interface members: And finally, move the new class to its own file: So far my ‘work’ was six mouse clicks long, the only thing that’s left to do manually here, is to add the Ioc-specific wiring-declaration and also to make the respective class non-public, which I regularly do to force my components to communicate exclusively via interfaces: This is what my Calculator class looks like as of now: using System; using LinFu.IoC.Configuration;   namespace Calculator {     [Implements(typeof(ICalculator))]     internal class Calculator : ICalculator     {         public double? LastResult         {             get             {                 throw new NotImplementedException();             }         }     } } Back to the test fixture, we have to put our IoC container to work: [TestFixture] public class CalculatorTest {     #region Fields       private readonly ServiceContainer container = new ServiceContainer();       #endregion // Fields       #region Setup/TearDown       [FixtureSetUp]     public void FixtureSetUp()     {        container.LoadFrom(AppDomain.CurrentDomain.BaseDirectory, "Calculator.dll");     }       ... Because I have a R# live template defined for the setup/teardown method skeleton as well, the only manual coding here again is the IoC-specific stuff: two lines, not more… The ‘Red’ (pt. 2) Now, the execution of the above test gives the following result: This time, the test outcome tells me that the method under test is called. And this is the point, where Derick and I seem to have somewhat different views on the subject: Of course, the test still is worthless regarding the red/green outcome (or: it’s still red for the wrong reasons, in that it gives a false negative). But as far as I am concerned, I’m not really interested in the test outcome at this point of the red-green-refactor cycle. Rather, I only want to assert that my test actually calls the right method. If that’s the case, I will happily go on to the ‘Green’ part… The ‘Green’ Making the test green is quite trivial. Just make LastResult an automatic property:     [Implements(typeof(ICalculator))]     internal class Calculator : ICalculator     {         public double? LastResult { get; private set; }     }         One more round… Now on to something slightly more demanding (cough…). Let’s state that our Calculator exposes an Add() method:         ...   /// <summary>         /// Adds the specified operands.         /// </summary>         /// <param name="operand1">The operand1.</param>         /// <param name="operand2">The operand2.</param>         /// <returns>The result of the additon.</returns>         /// <exception cref="ArgumentException">         /// Argument <paramref name="operand1"/> is &lt; 0.<br/>         /// -- or --<br/>         /// Argument <paramref name="operand2"/> is &lt; 0.         /// </exception>         double Add(double operand1, double operand2);       } // interface ICalculator A remark: I sometimes hear the complaint that xml comment stuff like the above is hard to read. That’s certainly true, but irrelevant to me, because I read xml code comments with the CR_Documentor tool window. And using that, it looks like this:   Apart from that, I’m heavily using xml code comments (see e.g. here for a detailed guide) because there is the possibility of automating help generation with nightly CI builds (using MS Sandcastle and the Sandcastle Help File Builder), and then publishing the results to some intranet location.  This way, a team always has first class, up-to-date technical documentation at hand about the current codebase. (And, also very important for speeding up things and avoiding typos: You have IntelliSense/AutoCompletion and R# support, and the comments are subject to compiler checking…).     Back to our Calculator again: Two more R# – clicks implement the Add() skeleton:         ...           public double Add(double operand1, double operand2)         {             throw new NotImplementedException();         }       } // class Calculator As we have stated in the interface definition (which actually serves as our requirement document!), the operands are not allowed to be negative. So let’s start implementing that. Here’s the test: [Test] [Row(-0.5, 2)] public void AddThrowsOnNegativeOperands(double operand1, double operand2) {     ICalculator calculator = container.GetService<ICalculator>();       Assert.Throws<ArgumentException>(() => calculator.Add(operand1, operand2)); } As you can see, I’m using a data-driven unit test method here, mainly for these two reasons: Because I know that I will have to do the same test for the second operand in a few seconds, I save myself from implementing another test method for this purpose. Rather, I only will have to add another Row attribute to the existing one. From the test report below, you can see that the argument values are explicitly printed out. This can be a valuable documentation feature even when everything is green: One can quickly review what values were tested exactly - the complete Gallio HTML-report (as it will be produced by the Continuous Integration runs) shows these values in a quite clear format (see below for an example). Back to our Calculator development again, this is what the test result tells us at the moment: So we’re red again, because there is not yet an implementation… Next we go on and implement the necessary parameter verification to become green again, and then we do the same thing for the second operand. To make a long story short, here’s the test and the method implementation at the end of the second cycle: // in CalculatorTest:   [Test] [Row(-0.5, 2)] [Row(295, -123)] public void AddThrowsOnNegativeOperands(double operand1, double operand2) {     ICalculator calculator = container.GetService<ICalculator>();       Assert.Throws<ArgumentException>(() => calculator.Add(operand1, operand2)); }   // in Calculator: public double Add(double operand1, double operand2) {     if (operand1 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand1");     }     if (operand2 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand2");     }     throw new NotImplementedException(); } So far, we have sheltered our method from unwanted input, and now we can safely operate on the parameters without further caring about their validity (this is my interpretation of the Fail Fast principle, which is regarded here in more detail). Now we can think about the method’s successful outcomes. First let’s write another test for that: [Test] [Row(1, 1, 2)] public void TestAdd(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       double result = calculator.Add(operand1, operand2);       Assert.AreEqual(expectedResult, result); } Again, I’m regularly using row based test methods for these kinds of unit tests. The above shown pattern proved to be extremely helpful for my development work, I call it the Defined-Input/Expected-Output test idiom: You define your input arguments together with the expected method result. There are two major benefits from that way of testing: In the course of refining a method, it’s very likely to come up with additional test cases. In our case, we might add tests for some edge cases like ‘one of the operands is zero’ or ‘the sum of the two operands causes an overflow’, or maybe there’s an external test protocol that has to be fulfilled (e.g. an ISO norm for medical software), and this results in the need of testing against additional values. In all these scenarios we only have to add another Row attribute to the test. Remember that the argument values are written to the test report, so as a side-effect this produces valuable documentation. (This can become especially important if the fulfillment of some sort of external requirements has to be proven). So your test method might look something like that in the end: [Test, Description("Arguments: operand1, operand2, expectedResult")] [Row(1, 1, 2)] [Row(0, 999999999, 999999999)] [Row(0, 0, 0)] [Row(0, double.MaxValue, double.MaxValue)] [Row(4, double.MaxValue - 2.5, double.MaxValue)] public void TestAdd(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       double result = calculator.Add(operand1, operand2);       Assert.AreEqual(expectedResult, result); } And this will produce the following HTML report (with Gallio):   Not bad for the amount of work we invested in it, huh? - There might be scenarios where reports like that can be useful for demonstration purposes during a Scrum sprint review… The last requirement to fulfill is that the LastResult property is expected to store the result of the last operation. I don’t show this here, it’s trivial enough and brings nothing new… And finally: Refactor (for the right reasons) To demonstrate my way of going through the refactoring portion of the red-green-refactor cycle, I added another method to our Calculator component, namely Subtract(). Here’s the code (tests and production): // CalculatorTest.cs:   [Test, Description("Arguments: operand1, operand2, expectedResult")] [Row(1, 1, 0)] [Row(0, 999999999, -999999999)] [Row(0, 0, 0)] [Row(0, double.MaxValue, -double.MaxValue)] [Row(4, double.MaxValue - 2.5, -double.MaxValue)] public void TestSubtract(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       double result = calculator.Subtract(operand1, operand2);       Assert.AreEqual(expectedResult, result); }   [Test, Description("Arguments: operand1, operand2, expectedResult")] [Row(1, 1, 0)] [Row(0, 999999999, -999999999)] [Row(0, 0, 0)] [Row(0, double.MaxValue, -double.MaxValue)] [Row(4, double.MaxValue - 2.5, -double.MaxValue)] public void TestSubtractGivesExpectedLastResult(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       calculator.Subtract(operand1, operand2);       Assert.AreEqual(expectedResult, calculator.LastResult); }   ...   // ICalculator.cs: /// <summary> /// Subtracts the specified operands. /// </summary> /// <param name="operand1">The operand1.</param> /// <param name="operand2">The operand2.</param> /// <returns>The result of the subtraction.</returns> /// <exception cref="ArgumentException"> /// Argument <paramref name="operand1"/> is &lt; 0.<br/> /// -- or --<br/> /// Argument <paramref name="operand2"/> is &lt; 0. /// </exception> double Subtract(double operand1, double operand2);   ...   // Calculator.cs:   public double Subtract(double operand1, double operand2) {     if (operand1 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand1");     }       if (operand2 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand2");     }       return (this.LastResult = operand1 - operand2).Value; }   Obviously, the argument validation stuff that was produced during the red-green part of our cycle duplicates the code from the previous Add() method. So, to avoid code duplication and minimize the number of code lines of the production code, we do an Extract Method refactoring. One more time, this is only a matter of a few mouse clicks (and giving the new method a name) with R#: Having done that, our production code finally looks like that: using System; using LinFu.IoC.Configuration;   namespace Calculator {     [Implements(typeof(ICalculator))]     internal class Calculator : ICalculator     {         #region ICalculator           public double? LastResult { get; private set; }           public double Add(double operand1, double operand2)         {             ThrowIfOneOperandIsInvalid(operand1, operand2);               return (this.LastResult = operand1 + operand2).Value;         }           public double Subtract(double operand1, double operand2)         {             ThrowIfOneOperandIsInvalid(operand1, operand2);               return (this.LastResult = operand1 - operand2).Value;         }           #endregion // ICalculator           #region Implementation (Helper)           private static void ThrowIfOneOperandIsInvalid(double operand1, double operand2)         {             if (operand1 < 0.0)             {                 throw new ArgumentException("Value must not be negative.", "operand1");             }               if (operand2 < 0.0)             {                 throw new ArgumentException("Value must not be negative.", "operand2");             }         }           #endregion // Implementation (Helper)       } // class Calculator   } // namespace Calculator But is the above worth the effort at all? It’s obviously trivial and not very impressive. All our tests were green (for the right reasons), and refactoring the code did not change anything. It’s not immediately clear how this refactoring work adds value to the project. Derick puts it like this: STOP! Hold on a second… before you go any further and before you even think about refactoring what you just wrote to make your test pass, you need to understand something: if your done with your requirements after making the test green, you are not required to refactor the code. I know… I’m speaking heresy, here. Toss me to the wolves, I’ve gone over to the dark side! Seriously, though… if your test is passing for the right reasons, and you do not need to write any test or any more code for you class at this point, what value does refactoring add? Derick immediately answers his own question: So why should you follow the refactor portion of red/green/refactor? When you have added code that makes the system less readable, less understandable, less expressive of the domain or concern’s intentions, less architecturally sound, less DRY, etc, then you should refactor it. I couldn’t state it more precise. From my personal perspective, I’d add the following: You have to keep in mind that real-world software systems are usually quite large and there are dozens or even hundreds of occasions where micro-refactorings like the above can be applied. It’s the sum of them all that counts. And to have a good overall quality of the system (e.g. in terms of the Code Duplication Percentage metric) you have to be pedantic on the individual, seemingly trivial cases. My job regularly requires the reading and understanding of ‘foreign’ code. So code quality/readability really makes a HUGE difference for me – sometimes it can be even the difference between project success and failure… Conclusions The above described development process emerged over the years, and there were mainly two things that guided its evolution (you might call it eternal principles, personal beliefs, or anything in between): Test-driven development is the normal, natural way of writing software, code-first is exceptional. So ‘doing TDD or not’ is not a question. And good, stable code can only reliably be produced by doing TDD (yes, I know: many will strongly disagree here again, but I’ve never seen high-quality code – and high-quality code is code that stood the test of time and causes low maintenance costs – that was produced code-first…) It’s the production code that pays our bills in the end. (Though I have seen customers these days who demand an acceptance test battery as part of the final delivery. Things seem to go into the right direction…). The test code serves ‘only’ to make the production code work. But it’s the number of delivered features which solely counts at the end of the day - no matter how much test code you wrote or how good it is. With these two things in mind, I tried to optimize my coding process for coding speed – or, in business terms: productivity - without sacrificing the principles of TDD (more than I’d do either way…).  As a result, I consider a ratio of about 3-5/1 for test code vs. production code as normal and desirable. In other words: roughly 60-80% of my code is test code (This might sound heavy, but that is mainly due to the fact that software development standards only begin to evolve. The entire software development profession is very young, historically seen; only at the very beginning, and there are no viable standards yet. If you think about software development as a kind of casting process, where the test code is the mold and the resulting production code is the final product, then the above ratio sounds no longer extraordinary…) Although the above might look like very much unnecessary work at first sight, it’s not. With the aid of the mentioned add-ins, doing all the above is a matter of minutes, sometimes seconds (while writing this post took hours and days…). The most important thing is to have the right tools at hand. Slow developer machines or the lack of a tool or something like that - for ‘saving’ a few 100 bucks -  is just not acceptable and a very bad decision in business terms (though I quite some times have seen and heard that…). Production of high-quality products needs the usage of high-quality tools. This is a platitude that every craftsman knows… The here described round-trip will take me about five to ten minutes in my real-world development practice. I guess it’s about 30% more time compared to developing the ‘traditional’ (code-first) way. But the so manufactured ‘product’ is of much higher quality and massively reduces maintenance costs, which is by far the single biggest cost factor, as I showed in this previous post: It's the maintenance, stupid! (or: Something is rotten in developerland.). In the end, this is a highly cost-effective way of software development… But on the other hand, there clearly is a trade-off here: coding speed vs. code quality/later maintenance costs. The here described development method might be a perfect fit for the overwhelming majority of software projects, but there certainly are some scenarios where it’s not - e.g. if time-to-market is crucial for a software project. So this is a business decision in the end. It’s just that you have to know what you’re doing and what consequences this might have… Some last words First, I’d like to thank Derick Bailey again. His two aforementioned posts (which I strongly recommend for reading) inspired me to think deeply about my own personal way of doing TDD and to clarify my thoughts about it. I wouldn’t have done that without this inspiration. I really enjoy that kind of discussions… I agree with him in all respects. But I don’t know (yet?) how to bring his insights into the described production process without slowing things down. The above described method proved to be very “good enough” in my practical experience. But of course, I’m open to suggestions here… My rationale for now is: If the test is initially red during the red-green-refactor cycle, the ‘right reason’ is: it actually calls the right method, but this method is not yet operational. Later on, when the cycle is finished and the tests become part of the regular, automated Continuous Integration process, ‘red’ certainly must occur for the ‘right reason’: in this phase, ‘red’ MUST mean nothing but an unfulfilled assertion - Fail By Assertion, Not By Anything Else!

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• Using HTML 5 SessionState to save rendered Page Content

  - by Rick Strahl

  HTML 5 SessionState and LocalStorage are very useful and super easy to use to manage client side state. For building rich client side or SPA style applications it's a vital feature to be able to cache user data as well as HTML content in order to swap pages in and out of the browser's DOM. What might not be so obvious is that you can also use the sessionState and localStorage objects even in classic server rendered HTML applications to provide caching features between pages. These APIs have been around for a long time and are supported by most relatively modern browsers and even all the way back to IE8, so you can use them safely in your Web applications. SessionState and LocalStorage are easy The APIs that make up sessionState and localStorage are very simple. Both object feature the same API interface which  is a simple, string based key value store that has getItem, setItem, removeitem, clear and  key methods. The objects are also pseudo array objects and so can be iterated like an array with  a length property and you have array indexers to set and get values with. Basic usage  for storing and retrieval looks like this (using sessionStorage, but the syntax is the same for localStorage - just switch the objects):// set var lastAccess = new Date().getTime(); if (sessionStorage) sessionStorage.setItem("myapp_time", lastAccess.toString()); // retrieve in another page or on a refresh var time = null; if (sessionStorage) time = sessionStorage.getItem("myapp_time"); if (time) time = new Date(time * 1); else time = new Date(); sessionState stores data that is browser session specific and that has a liftetime of the active browser session or window. Shut down the browser or tab and the storage goes away. localStorage uses the same API interface, but the lifetime of the data is permanently stored in the browsers storage area until deleted via code or by clearing out browser cookies (not the cache). Both sessionStorage and localStorage space is limited. The spec is ambiguous about this - supposedly sessionStorage should allow for unlimited size, but it appears that most WebKit browsers support only 2.5mb for either object. This means you have to be careful what you store especially since other applications might be running on the same domain and also use the storage mechanisms. That said 2.5mb worth of character data is quite a bit and would go a long way. The easiest way to get a feel for how sessionState and localStorage work is to look at a simple example. You can go check out the following example online in Plunker: http://plnkr.co/edit/0ICotzkoPjHaWa70GlRZ?p=preview which looks like this: Plunker is an online HTML/JavaScript editor that lets you write and run Javascript code and similar to JsFiddle, but a bit cleaner to work in IMHO (thanks to John Papa for turning me on to it). The sample has two text boxes with counts that update session/local storage every time you click the related button. The counts are 'cached' in Session and Local storage. The point of these examples is that both counters survive full page reloads, and the LocalStorage counter survives a complete browser shutdown and restart. Go ahead and try it out by clicking the Reload button after updating both counters and then shutting down the browser completely and going back to the same URL (with the same browser). What you should see is that reloads leave both counters intact at the counted values, while a browser restart will leave only the local storage counter intact. The code to deal with the SessionStorage (and LocalStorage not shown here) in the example is isolated into a couple of wrapper methods to simplify the code: function getSessionCount() { var count = 0; if (sessionStorage) { var count = sessionStorage.getItem("ss_count"); count = !count ? 0 : count * 1; } $("#txtSession").val(count); return count; } function setSessionCount(count) { if (sessionStorage) sessionStorage.setItem("ss_count", count.toString()); } These two functions essentially load and store a session counter value. The two key methods used here are: sessionStorage.getItem(key); sessionStorage.setItem(key,stringVal); Note that the value given to setItem and return by getItem has to be a string. If you pass another type you get an error. Don't let that limit you though - you can easily enough store JSON data in a variable so it's quite possible to pass complex objects and store them into a single sessionStorage value:var user = { name: "Rick", id="ricks", level=8 } sessionStorage.setItem("app_user",JSON.stringify(user)); to retrieve it:var user = sessionStorage.getItem("app_user"); if (user) user = JSON.parse(user); Simple! If you're using the Chrome Developer Tools (F12) you can also check out the session and local storage state on the Resource tab:   You can also use this tool to refresh or remove entries from storage. What we just looked at is a purely client side implementation where a couple of counters are stored. For rich client centric AJAX applications sessionStorage and localStorage provide a very nice and simple API to store application state while the application is running. But you can also use these storage mechanisms to manage server centric HTML applications when you combine server rendering with some JavaScript to perform client side data caching. You can both store some state information and data on the client (ie. store a JSON object and carry it forth between server rendered HTML requests) or you can use it for good old HTTP based caching where some rendered HTML is saved and then restored later. Let's look at the latter with a real life example. Why do I need Client-side Page Caching for Server Rendered HTML? I don't know about you, but in a lot of my existing server driven applications I have lists that display a fair amount of data. Typically these lists contain links to then drill down into more specific data either for viewing or editing. You can then click on a link and go off to a detail page that provides more concise content. So far so good. But now you're done with the detail page and need to get back to the list, so you click on a 'bread crumbs trail' or an application level 'back to list' button and… …you end up back at the top of the list - the scroll position, the current selection in some cases even filters conditions - all gone with the wind. You've left behind the state of the list and are starting from scratch in your browsing of the list from the top. Not cool! Sound familiar? This a pretty common scenario with server rendered HTML content where it's so common to display lists to drill into, only to lose state in the process of returning back to the original list. Look at just about any traditional forums application, or even StackOverFlow to see what I mean here. Scroll down a bit to look at a post or entry, drill in then use the bread crumbs or tab to go back… In some cases returning to the top of a list is not a big deal. On StackOverFlow that sort of works because content is turning around so quickly you probably want to actually look at the top posts. Not always though - if you're browsing through a list of search topics you're interested in and drill in there's no way back to that position. Essentially anytime you're actively browsing the items in the list, that's when state becomes important and if it's not handled the user experience can be really disrupting. Content Caching If you're building client centric SPA style applications this is a fairly easy to solve problem - you tend to render the list once and then update the page content to overlay the detail content, only hiding the list temporarily until it's used again later. It's relatively easy to accomplish this simply by hiding content on the page and later making it visible again. But if you use server rendered content, hanging on to all the detail like filters, selections and scroll position is not quite as easy. Or is it??? This is where sessionStorage comes in handy. What if we just save the rendered content of a previous page, and then restore it when we return to this page based on a special flag that tells us to use the cached version? Let's see how we can do this. A real World Use Case Recently my local ISP asked me to help out with updating an ancient classifieds application. They had a very busy, local classifieds app that was originally an ASP classic application. The old app was - wait for it: frames based - and even though I lobbied against it, the decision was made to keep the frames based layout to allow rapid browsing of the hundreds of posts that are made on a daily basis. The primary reason they wanted this was precisely for the ability to quickly browse content item by item. While I personally hate working with Frames, I have to admit that the UI actually works well with the frames layout as long as you're running on a large desktop screen. You can check out the frames based desktop site here: http://classifieds.gorge.net/ However when I rebuilt the app I also added a secondary view that doesn't use frames. The main reason for this of course was for mobile displays which work horribly with frames. So there's a somewhat mobile friendly interface to the interface, which ditches the frames and uses some responsive design tweaking for mobile capable operation: http://classifeds.gorge.net/mobile  (or browse the base url with your browser width under 800px)   Here's what the mobile, non-frames view looks like:   As you can see this means that the list of classifieds posts now is a list and there's a separate page for drilling down into the item. And of course… originally we ran into that usability issue I mentioned earlier where the browse, view detail, go back to the list cycle resulted in lost list state. Originally in mobile mode you scrolled through the list, found an item to look at and drilled in to display the item detail. Then you clicked back to the list and BAM - you've lost your place. Because there are so many items added on a daily basis the full list is never fully loaded, but rather there's a "Load Additional Listings"  entry at the button. Not only did we originally lose our place when coming back to the list, but any 'additionally loaded' items are no longer there because the list was now rendering  as if it was the first page hit. The additional listings, and any filters, the selection of an item all were lost. Major Suckage! Using Client SessionStorage to cache Server Rendered Content To work around this problem I decided to cache the rendered page content from the list in SessionStorage. Anytime the list renders or is updated with Load Additional Listings, the page HTML is cached and stored in Session Storage. Any back links from the detail page or the login or write entry forms then point back to the list page with a back=true query string parameter. If the server side sees this parameter it doesn't render the part of the page that is cached. Instead the client side code retrieves the data from the sessionState cache and simply inserts it into the page. It sounds pretty simple, and the overall the process is really easy, but there are a few gotchas that I'll discuss in a minute. But first let's look at the implementation. Let's start with the server side here because that'll give a quick idea of the doc structure. As I mentioned the server renders data from an ASP.NET MVC view. On the list page when returning to the list page from the display page (or a host of other pages) looks like this: https://classifieds.gorge.net/list?back=True The query string value is a flag, that indicates whether the server should render the HTML. Here's what the top level MVC Razor view for the list page looks like:@model MessageListViewModel @{ ViewBag.Title = "Classified Listing"; bool isBack = !string.IsNullOrEmpty(Request.QueryString["back"]); } <form method="post" action="@Url.Action("list")"> <div id="SizingContainer"> @if (!isBack) { @Html.Partial("List_CommandBar_Partial", Model) <div id="PostItemContainer" class="scrollbox" xstyle="-webkit-overflow-scrolling: touch;"> @Html.Partial("List_Items_Partial", Model) @if (Model.RequireLoadEntry) { <div class="postitem loadpostitems" style="padding: 15px;"> <div id="LoadProgress" class="smallprogressright"></div> <div class="control-progress"> Load additional listings... </div> </div> } </div> } </div> </form> As you can see the query string triggers a conditional block that if set is simply not rendered. The content inside of #SizingContainer basically holds  the entire page's HTML sans the headers and scripts, but including the filter options and menu at the top. In this case this makes good sense - in other situations the fact that the menu or filter options might be dynamically updated might make you only cache the list rather than essentially the entire page. In this particular instance all of the content works and produces the proper result as both the list along with any filter conditions in the form inputs are restored. Ok, let's move on to the client. On the client there are two page level functions that deal with saving and restoring state. Like the counter example I showed earlier, I like to wrap the logic to save and restore values from sessionState into a separate function because they are almost always used in several places.page.saveData = function(id) { if (!sessionStorage) return; var data = { id: id, scroll: $("#PostItemContainer").scrollTop(), html: $("#SizingContainer").html() }; sessionStorage.setItem("list_html",JSON.stringify(data)); }; page.restoreData = function() { if (!sessionStorage) return; var data = sessionStorage.getItem("list_html"); if (!data) return null; return JSON.parse(data); }; The data that is saved is an object which contains an ID which is the selected element when the user clicks and a scroll position. These two values are used to reset the scroll position when the data is used from the cache. Finally the html from the #SizingContainer element is stored, which makes for the bulk of the document's HTML. In this application the HTML captured could be a substantial bit of data. If you recall, I mentioned that the server side code renders a small chunk of data initially and then gets more data if the user reads through the first 50 or so items. The rest of the items retrieved can be rather sizable. Other than the JSON deserialization that's Ok. Since I'm using SessionStorage the storage space has no immediate limits. Next is the core logic to handle saving and restoring the page state. At first though this would seem pretty simple, and in some cases it might be, but as the following code demonstrates there are a few gotchas to watch out for. Here's the relevant code I use to save and restore:$( function() { … var isBack = getUrlEncodedKey("back", location.href); if (isBack) { // remove the back key from URL setUrlEncodedKey("back", "", location.href); var data = page.restoreData(); // restore from sessionState if (!data) { // no data - force redisplay of the server side default list window.location = "list"; return; } $("#SizingContainer").html(data.html); var el = $(".postitem[data-id=" + data.id + "]"); $(".postitem").removeClass("highlight"); el.addClass("highlight"); $("#PostItemContainer").scrollTop(data.scroll); setTimeout(function() { el.removeClass("highlight"); }, 2500); } else if (window.noFrames) page.saveData(null); // save when page loads $("#SizingContainer").on("click", ".postitem", function() { var id = $(this).attr("data-id"); if (!id) return true; if (window.noFrames) page.saveData(id); var contentFrame = window.parent.frames["Content"]; if (contentFrame) contentFrame.location.href = "show/" + id; else window.location.href = "show/" + id; return false; }); … The code starts out by checking for the back query string flag which triggers restoring from the client cache. If cached the cached data structure is read from sessionStorage. It's important here to check if data was returned. If the user had back=true on the querystring but there is no cached data, he likely bookmarked this page or otherwise shut down the browser and came back to this URL. In that case the server didn't render any detail and we have no cached data, so all we can do is redirect to the original default list view using window.location. If we continued the page would render no data - so make sure to always check the cache retrieval result. Always! If there is data the it's loaded and the data.html data is restored back into the document by simply injecting the HTML back into the document's #SizingContainer element:$("#SizingContainer").html(data.html); It's that simple and it's quite quick even with a fully loaded list of additional items and on a phone. The actual HTML data is stored to the cache on every page load initially and then again when the user clicks on an element to navigate to a particular listing. The former ensures that the client cache always has something in it, and the latter updates with additional information for the selected element. For the click handling I use a data-id attribute on the list item (.postitem) in the list and retrieve the id from that. That id is then used to navigate to the actual entry as well as storing that Id value in the saved cached data. The id is used to reset the selection by searching for the data-id value in the restored elements. The overall process of this save/restore process is pretty straight forward and it doesn't require a bunch of code, yet it yields a huge improvement in the usability of the site on mobile devices (or anybody who uses the non-frames view). Some things to watch out for As easy as it conceptually seems to simply store and retrieve cached content, you have to be quite aware what type of content you are caching. The code above is all that's specific to cache/restore cycle and it works, but it took a few tweaks to the rest of the script code and server code to make it all work. There were a few gotchas that weren't immediately obvious. Here are a few things to pay attention to: Event Handling Logic Timing of manipulating DOM events Inline Script Code Bookmarking to the Cache Url when no cache exists Do you have inline script code in your HTML? That script code isn't going to run if you restore from cache and simply assign or it may not run at the time you think it would normally in the DOM rendering cycle. JavaScript Event Hookups The biggest issue I ran into with this approach almost immediately is that originally I had various static event handlers hooked up to various UI elements that are now cached. If you have an event handler like:$("#btnSearch").click( function() {…}); that works fine when the page loads with server rendered HTML, but that code breaks when you now load the HTML from cache. Why? Because the elements you're trying to hook those events to may not actually be there - yet. Luckily there's an easy workaround for this by using deferred events. With jQuery you can use the .on() event handler instead:$("#SelectionContainer").on("click","#btnSearch", function() {…}); which monitors a parent element for the events and checks for the inner selector elements to handle events on. This effectively defers to runtime event binding, so as more items are added to the document bindings still work. For any cached content use deferred events. Timing of manipulating DOM Elements Along the same lines make sure that your DOM manipulation code follows the code that loads the cached content into the page so that you don't manipulate DOM elements that don't exist just yet. Ideally you'll want to check for the condition to restore cached content towards the top of your script code, but that can be tricky if you have components or other logic that might not all run in a straight line. Inline Script Code Here's another small problem I ran into: I use a DateTime Picker widget I built a while back that relies on the jQuery date time picker. I also created a helper function that allows keyboard date navigation into it that uses JavaScript logic. Because MVC's limited 'object model' the only way to embed widget content into the page is through inline script. This code broken when I inserted the cached HTML into the page because the script code was not available when the component actually got injected into the page. As the last bullet - it's a matter of timing. There's no good work around for this - in my case I pulled out the jQuery date picker and relied on native <input type="date" /> logic instead - a better choice these days anyway, especially since this view is meant to be primarily to serve mobile devices which actually support date input through the browser (unlike desktop browsers of which only WebKit seems to support it). Bookmarking Cached Urls When you cache HTML content you have to make a decision whether you cache on the client and also not render that same content on the server. In the Classifieds app I didn't render server side content so if the user comes to the page with back=True and there is no cached content I have to a have a Plan B. Typically this happens when somebody ends up bookmarking the back URL. The easiest and safest solution for this scenario is to ALWAYS check the cache result to make sure it exists and if not have a safe URL to go back to - in this case to the plain uncached list URL which amounts to effectively redirecting. This seems really obvious in hindsight, but it's easy to overlook and not see a problem until much later, when it's not obvious at all why the page is not rendering anything. Don't use <body> to replace Content Since we're practically replacing all the HTML in the page it may seem tempting to simply replace the HTML content of the <body> tag. Don't. The body tag usually contains key things that should stay in the page and be there when it loads. Specifically script tags and elements and possibly other embedded content. It's best to create a top level DOM element specifically as a placeholder container for your cached content and wrap just around the actual content you want to replace. In the app above the #SizingContainer is that container. Other Approaches The approach I've used for this application is kind of specific to the existing server rendered application we're running and so it's just one approach you can take with caching. However for server rendered content caching this is a pattern I've used in a few apps to retrofit some client caching into list displays. In this application I took the path of least resistance to the existing server rendering logic. Here are a few other ways that come to mind: Using Partial HTML Rendering via AJAXInstead of rendering the page initially on the server, the page would load empty and the client would render the UI by retrieving the respective HTML and embedding it into the page from a Partial View. This effectively makes the initial rendering and the cached rendering logic identical and removes the server having to decide whether this request needs to be rendered or not (ie. not checking for a back=true switch). All the logic related to caching is made on the client in this case. Using JSON Data and Client RenderingThe hardcore client option is to do the whole UI SPA style and pull data from the server and then use client rendering or databinding to pull the data down and render using templates or client side databinding with knockout/angular et al. As with the Partial Rendering approach the advantage is that there's no difference in the logic between pulling the data from cache or rendering from scratch other than the initial check for the cache request. Of course if the app is a  full on SPA app, then caching may not be required even - the list could just stay in memory and be hidden and reactivated. I'm sure there are a number of other ways this can be handled as well especially using  AJAX. AJAX rendering might simplify the logic, but it also complicates search engine optimization since there's no content loaded initially. So there are always tradeoffs and it's important to look at all angles before deciding on any sort of caching solution in general. State of the Session SessionState and LocalStorage are easy to use in client code and can be integrated even with server centric applications to provide nice caching features of content and data. In this post I've shown a very specific scenario of storing HTML content for the purpose of remembering list view data and state and making the browsing experience for lists a bit more friendly, especially if there's dynamically loaded content involved. If you haven't played with sessionStorage or localStorage I encourage you to give it a try. There's a lot of cool stuff that you can do with this beyond the specific scenario I've covered here… Resources Overview of localStorage (also applies to sessionStorage) Web Storage Compatibility Modernizr Test Suite© Rick Strahl, West Wind Technologies, 2005-2013Posted in JavaScript  HTML5  ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Did I lose my RAID again?

  - by BarsMonster

  Hi! A little history: 2 years ago I was really excited to find out that mdadm is so powerful that it even can reshape arrays, so you can start with a smaller array and then grow it as you need. I've bought 3x1Tb drives and made a RAID-5. It was fine for a year. Then I bought 2x more, and tried to reshape to RAID-6 out of 5 drives, and due to some mess with superblock versions, lost all content. Had to rebuild it from scratch, but 2Tb of data were gone. Yesterday I bought 2 more drives, and this time I had everything: properly built array, UPS. I've disabled write intent map, added 2 new drives as spares and run a command to grow array to 7-disks. It started working, but speed was ridiculously slow, ~100kb/sec. After processing first 37Mb at such an amazing speed, one of old HDDs fails. I properly shutdown the PC and disconnected the failed drive. After bootup it appeared that it recreated the intent map as it was still in mdadm config, so I removed it from config and rebooted again. Now all I see is that all mdadm processes deadlock, and don't do anything. PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1937 root 20 0 12992 608 444 D 0 0.1 0:00.00 mdadm 2283 root 20 0 12992 852 704 D 0 0.1 0:00.01 mdadm 2287 root 20 0 0 0 0 D 0 0.0 0:00.01 md0_reshape 2288 root 18 -2 12992 820 676 D 0 0.1 0:00.01 mdadm And all I see in mdstat is: $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid6 sdb1[1] sdg1[4] sdf1[7] sde1[6] sdd1[0] sdc1[5] 2929683456 blocks super 1.2 level 6, 1024k chunk, algorithm 2 [7/6] [UU_UUUU] [>....................] reshape = 0.0% (37888/976561152) finish=567604147.2min speed=0K/sec I've already tried mdadm 2.6.7, 3.1.4 and 3.2 - nothing helps. Did I lose my data again? Any suggestions on how can I make this work? OS is Ubuntu Server 10.04.2. PS. Needless to say, the data is inaccessible - I cannot mount /dev/md0 to save the most valuable data. You can see my disappointment - the very specific thing I was excited about failed twice taking 5Tb of my data with it. Update: It appears there is some nice info in kern.log: 21:38:48 ...: [ 166.522055] raid5: reshape will continue 21:38:48 ...: [ 166.522085] raid5: device sdb1 operational as raid disk 1 21:38:48 ...: [ 166.522091] raid5: device sdg1 operational as raid disk 4 21:38:48 ...: [ 166.522097] raid5: device sdf1 operational as raid disk 5 21:38:48 ...: [ 166.522102] raid5: device sde1 operational as raid disk 6 21:38:48 ...: [ 166.522107] raid5: device sdd1 operational as raid disk 0 21:38:48 ...: [ 166.522111] raid5: device sdc1 operational as raid disk 3 21:38:48 ...: [ 166.523942] raid5: allocated 7438kB for md0 21:38:48 ...: [ 166.524041] 1: w=1 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524050] 4: w=2 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524056] 5: w=3 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524062] 6: w=4 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524068] 0: w=5 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524073] 3: w=6 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524079] raid5: raid level 6 set md0 active with 6 out of 7 devices, algorithm 2 21:38:48 ...: [ 166.524519] RAID5 conf printout: 21:38:48 ...: [ 166.524523] --- rd:7 wd:6 21:38:48 ...: [ 166.524528] disk 0, o:1, dev:sdd1 21:38:48 ...: [ 166.524532] disk 1, o:1, dev:sdb1 21:38:48 ...: [ 166.524537] disk 3, o:1, dev:sdc1 21:38:48 ...: [ 166.524541] disk 4, o:1, dev:sdg1 21:38:48 ...: [ 166.524545] disk 5, o:1, dev:sdf1 21:38:48 ...: [ 166.524550] disk 6, o:1, dev:sde1 21:38:48 ...: [ 166.524553] ...ok start reshape thread 21:38:48 ...: [ 166.524727] md0: detected capacity change from 0 to 2999995858944 21:38:48 ...: [ 166.524735] md: reshape of RAID array md0 21:38:48 ...: [ 166.524740] md: minimum _guaranteed_ speed: 1000 KB/sec/disk. 21:38:48 ...: [ 166.524745] md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reshape. 21:38:48 ...: [ 166.524756] md: using 128k window, over a total of 976561152 blocks. 21:39:05 ...: [ 166.525013] md0: 21:42:04 ...: [ 362.520063] INFO: task mdadm:1937 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520068] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520073] mdadm D 00000000ffffffff 0 1937 1 0x00000000 21:42:04 ...: [ 362.520083] ffff88002ef4f5d8 0000000000000082 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520092] ffff88002eb5b198 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5ade0 21:42:04 ...: [ 362.520100] 0000000000015bc0 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5b198 21:42:04 ...: [ 362.520107] Call Trace: 21:42:04 ...: [ 362.520133] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:42:04 ...: [ 362.520148] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:42:04 ...: [ 362.520159] [<ffffffffa0228413>] make_request+0x243/0x4b0 [raid456] 21:42:04 ...: [ 362.520169] [<ffffffffa0221a90>] ? release_stripe+0x50/0x70 [raid456] 21:42:04 ...: [ 362.520179] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:42:04 ...: [ 362.520188] [<ffffffff81414df0>] md_make_request+0xc0/0x130 21:42:04 ...: [ 362.520194] [<ffffffff81414df0>] ? md_make_request+0xc0/0x130 21:42:04 ...: [ 362.520205] [<ffffffff8129f8c1>] generic_make_request+0x1b1/0x4f0 21:42:04 ...: [ 362.520214] [<ffffffff810f6515>] ? mempool_alloc_slab+0x15/0x20 21:42:04 ...: [ 362.520222] [<ffffffff8116c2ec>] ? alloc_buffer_head+0x1c/0x60 21:42:04 ...: [ 362.520230] [<ffffffff8129fc80>] submit_bio+0x80/0x110 21:42:04 ...: [ 362.520236] [<ffffffff8116c849>] submit_bh+0xf9/0x140 21:42:04 ...: [ 362.520244] [<ffffffff8116f124>] block_read_full_page+0x274/0x3b0 21:42:04 ...: [ 362.520251] [<ffffffff81172c90>] ? blkdev_get_block+0x0/0x70 21:42:04 ...: [ 362.520258] [<ffffffff8110d875>] ? __inc_zone_page_state+0x35/0x40 21:42:04 ...: [ 362.520265] [<ffffffff810f46d8>] ? add_to_page_cache_locked+0xe8/0x160 21:42:04 ...: [ 362.520272] [<ffffffff81173d78>] blkdev_readpage+0x18/0x20 21:42:04 ...: [ 362.520279] [<ffffffff810f484b>] __read_cache_page+0x7b/0xe0 21:42:04 ...: [ 362.520285] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:42:04 ...: [ 362.520290] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:42:04 ...: [ 362.520297] [<ffffffff810f57dc>] do_read_cache_page+0x3c/0x120 21:42:04 ...: [ 362.520304] [<ffffffff810f5909>] read_cache_page_async+0x19/0x20 21:42:04 ...: [ 362.520310] [<ffffffff810f591e>] read_cache_page+0xe/0x20 21:42:04 ...: [ 362.520317] [<ffffffff811a6cb0>] read_dev_sector+0x30/0xa0 21:42:04 ...: [ 362.520324] [<ffffffff811a7fcd>] amiga_partition+0x6d/0x460 21:42:04 ...: [ 362.520331] [<ffffffff811a7938>] check_partition+0x138/0x190 21:42:04 ...: [ 362.520338] [<ffffffff811a7a7a>] rescan_partitions+0xea/0x2f0 21:42:04 ...: [ 362.520344] [<ffffffff811744c7>] __blkdev_get+0x267/0x3d0 21:42:04 ...: [ 362.520350] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:42:04 ...: [ 362.520356] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:42:04 ...: [ 362.520362] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:42:04 ...: [ 362.520369] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:42:04 ...: [ 362.520377] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:42:04 ...: [ 362.520385] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:42:04 ...: [ 362.520391] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:42:04 ...: [ 362.520398] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:42:04 ...: [ 362.520406] [<ffffffff811134a8>] ? unmap_vmas+0x178/0x310 21:42:04 ...: [ 362.520414] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:42:04 ...: [ 362.520421] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:42:04 ...: [ 362.520428] [<ffffffff811418b0>] sys_open+0x20/0x30 21:42:04 ...: [ 362.520437] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:42:04 ...: [ 362.520446] INFO: task mdadm:2283 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520450] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520454] mdadm D 0000000000000000 0 2283 2212 0x00000000 21:42:04 ...: [ 362.520462] ffff88002cca7d98 0000000000000086 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520470] ffff88002ededf78 ffff88002cca7fd8 0000000000015bc0 ffff88002ededbc0 21:42:04 ...: [ 362.520478] 0000000000015bc0 ffff88002cca7fd8 0000000000015bc0 ffff88002ededf78 21:42:04 ...: [ 362.520485] Call Trace: 21:42:04 ...: [ 362.520495] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:42:04 ...: [ 362.520502] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:42:04 ...: [ 362.520508] [<ffffffff8117404d>] __blkdev_put+0x3d/0x190 21:42:04 ...: [ 362.520514] [<ffffffff811741b0>] blkdev_put+0x10/0x20 21:42:04 ...: [ 362.520520] [<ffffffff811741f3>] blkdev_close+0x33/0x60 21:42:04 ...: [ 362.520527] [<ffffffff81145375>] __fput+0xf5/0x210 21:42:04 ...: [ 362.520534] [<ffffffff811454b5>] fput+0x25/0x30 21:42:04 ...: [ 362.520540] [<ffffffff811415ad>] filp_close+0x5d/0x90 21:42:04 ...: [ 362.520546] [<ffffffff81141697>] sys_close+0xb7/0x120 21:42:04 ...: [ 362.520553] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:42:04 ...: [ 362.520559] INFO: task md0_reshape:2287 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520563] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520567] md0_reshape D ffff88003aee96f0 0 2287 2 0x00000000 21:42:04 ...: [ 362.520575] ffff88003cf05a70 0000000000000046 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520582] ffff88003aee9aa8 ffff88003cf05fd8 0000000000015bc0 ffff88003aee96f0 21:42:04 ...: [ 362.520590] 0000000000015bc0 ffff88003cf05fd8 0000000000015bc0 ffff88003aee9aa8 21:42:04 ...: [ 362.520597] Call Trace: 21:42:04 ...: [ 362.520608] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:42:04 ...: [ 362.520616] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:42:04 ...: [ 362.520626] [<ffffffffa0226f80>] reshape_request+0x4c0/0x9a0 [raid456] 21:42:04 ...: [ 362.520634] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:42:04 ...: [ 362.520644] [<ffffffffa022777a>] sync_request+0x31a/0x3a0 [raid456] 21:42:04 ...: [ 362.520651] [<ffffffff81052713>] ? __wake_up+0x53/0x70 21:42:04 ...: [ 362.520658] [<ffffffff814156b1>] md_do_sync+0x621/0xbb0 21:42:04 ...: [ 362.520668] [<ffffffff810387b9>] ? default_spin_lock_flags+0x9/0x10 21:42:04 ...: [ 362.520675] [<ffffffff8141640c>] md_thread+0x5c/0x130 21:42:04 ...: [ 362.520681] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:42:04 ...: [ 362.520688] [<ffffffff814163b0>] ? md_thread+0x0/0x130 21:42:04 ...: [ 362.520694] [<ffffffff81084416>] kthread+0x96/0xa0 21:42:04 ...: [ 362.520701] [<ffffffff810131ea>] child_rip+0xa/0x20 21:42:04 ...: [ 362.520707] [<ffffffff81084380>] ? kthread+0x0/0xa0 21:42:04 ...: [ 362.520713] [<ffffffff810131e0>] ? child_rip+0x0/0x20 21:42:04 ...: [ 362.520718] INFO: task mdadm:2288 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520721] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520725] mdadm D 0000000000000000 0 2288 1 0x00000000 21:42:04 ...: [ 362.520733] ffff88002cca9c18 0000000000000086 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520741] ffff88003aee83b8 ffff88002cca9fd8 0000000000015bc0 ffff88003aee8000 21:42:04 ...: [ 362.520748] 0000000000015bc0 ffff88002cca9fd8 0000000000015bc0 ffff88003aee83b8 21:42:04 ...: [ 362.520755] Call Trace: 21:42:04 ...: [ 362.520763] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:42:04 ...: [ 362.520771] [<ffffffff812a6d50>] ? exact_match+0x0/0x10 21:42:04 ...: [ 362.520777] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:42:04 ...: [ 362.520783] [<ffffffff811742c8>] __blkdev_get+0x68/0x3d0 21:42:04 ...: [ 362.520790] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:42:04 ...: [ 362.520795] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:42:04 ...: [ 362.520801] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:42:04 ...: [ 362.520808] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:42:04 ...: [ 362.520815] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:42:04 ...: [ 362.520821] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:42:04 ...: [ 362.520828] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:42:04 ...: [ 362.520834] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:42:04 ...: [ 362.520841] [<ffffffff810ff0e1>] ? lru_cache_add_lru+0x21/0x40 21:42:04 ...: [ 362.520848] [<ffffffff8111109c>] ? do_anonymous_page+0x11c/0x330 21:42:04 ...: [ 362.520855] [<ffffffff81115d5f>] ? handle_mm_fault+0x31f/0x3c0 21:42:04 ...: [ 362.520862] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:42:04 ...: [ 362.520868] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:42:04 ...: [ 362.520874] [<ffffffff811418b0>] sys_open+0x20/0x30 21:42:04 ...: [ 362.520882] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:44:04 ...: [ 482.520065] INFO: task mdadm:1937 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520077] mdadm D 00000000ffffffff 0 1937 1 0x00000000 21:44:04 ...: [ 482.520087] ffff88002ef4f5d8 0000000000000082 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520096] ffff88002eb5b198 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5ade0 21:44:04 ...: [ 482.520104] 0000000000015bc0 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5b198 21:44:04 ...: [ 482.520112] Call Trace: 21:44:04 ...: [ 482.520139] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:44:04 ...: [ 482.520154] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:44:04 ...: [ 482.520165] [<ffffffffa0228413>] make_request+0x243/0x4b0 [raid456] 21:44:04 ...: [ 482.520175] [<ffffffffa0221a90>] ? release_stripe+0x50/0x70 [raid456] 21:44:04 ...: [ 482.520185] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:44:04 ...: [ 482.520194] [<ffffffff81414df0>] md_make_request+0xc0/0x130 21:44:04 ...: [ 482.520201] [<ffffffff81414df0>] ? md_make_request+0xc0/0x130 21:44:04 ...: [ 482.520212] [<ffffffff8129f8c1>] generic_make_request+0x1b1/0x4f0 21:44:04 ...: [ 482.520221] [<ffffffff810f6515>] ? mempool_alloc_slab+0x15/0x20 21:44:04 ...: [ 482.520229] [<ffffffff8116c2ec>] ? alloc_buffer_head+0x1c/0x60 21:44:04 ...: [ 482.520237] [<ffffffff8129fc80>] submit_bio+0x80/0x110 21:44:04 ...: [ 482.520244] [<ffffffff8116c849>] submit_bh+0xf9/0x140 21:44:04 ...: [ 482.520252] [<ffffffff8116f124>] block_read_full_page+0x274/0x3b0 21:44:04 ...: [ 482.520258] [<ffffffff81172c90>] ? blkdev_get_block+0x0/0x70 21:44:04 ...: [ 482.520266] [<ffffffff8110d875>] ? __inc_zone_page_state+0x35/0x40 21:44:04 ...: [ 482.520273] [<ffffffff810f46d8>] ? add_to_page_cache_locked+0xe8/0x160 21:44:04 ...: [ 482.520280] [<ffffffff81173d78>] blkdev_readpage+0x18/0x20 21:44:04 ...: [ 482.520286] [<ffffffff810f484b>] __read_cache_page+0x7b/0xe0 21:44:04 ...: [ 482.520293] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:44:04 ...: [ 482.520299] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:44:04 ...: [ 482.520306] [<ffffffff810f57dc>] do_read_cache_page+0x3c/0x120 21:44:04 ...: [ 482.520313] [<ffffffff810f5909>] read_cache_page_async+0x19/0x20 21:44:04 ...: [ 482.520319] [<ffffffff810f591e>] read_cache_page+0xe/0x20 21:44:04 ...: [ 482.520327] [<ffffffff811a6cb0>] read_dev_sector+0x30/0xa0 21:44:04 ...: [ 482.520334] [<ffffffff811a7fcd>] amiga_partition+0x6d/0x460 21:44:04 ...: [ 482.520341] [<ffffffff811a7938>] check_partition+0x138/0x190 21:44:04 ...: [ 482.520348] [<ffffffff811a7a7a>] rescan_partitions+0xea/0x2f0 21:44:04 ...: [ 482.520355] [<ffffffff811744c7>] __blkdev_get+0x267/0x3d0 21:44:04 ...: [ 482.520361] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:44:04 ...: [ 482.520367] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:44:04 ...: [ 482.520373] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:44:04 ...: [ 482.520380] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:44:04 ...: [ 482.520388] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:44:04 ...: [ 482.520396] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:44:04 ...: [ 482.520403] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:44:04 ...: [ 482.520410] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:44:04 ...: [ 482.520417] [<ffffffff811134a8>] ? unmap_vmas+0x178/0x310 21:44:04 ...: [ 482.520426] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:44:04 ...: [ 482.520432] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:44:04 ...: [ 482.520438] [<ffffffff811418b0>] sys_open+0x20/0x30 21:44:04 ...: [ 482.520447] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:44:04 ...: [ 482.520458] INFO: task mdadm:2283 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520462] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520467] mdadm D 0000000000000000 0 2283 2212 0x00000000 21:44:04 ...: [ 482.520475] ffff88002cca7d98 0000000000000086 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520483] ffff88002ededf78 ffff88002cca7fd8 0000000000015bc0 ffff88002ededbc0 21:44:04 ...: [ 482.520490] 0000000000015bc0 ffff88002cca7fd8 0000000000015bc0 ffff88002ededf78 21:44:04 ...: [ 482.520498] Call Trace: 21:44:04 ...: [ 482.520508] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:44:04 ...: [ 482.520515] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:44:04 ...: [ 482.520521] [<ffffffff8117404d>] __blkdev_put+0x3d/0x190 21:44:04 ...: [ 482.520527] [<ffffffff811741b0>] blkdev_put+0x10/0x20 21:44:04 ...: [ 482.520533] [<ffffffff811741f3>] blkdev_close+0x33/0x60 21:44:04 ...: [ 482.520541] [<ffffffff81145375>] __fput+0xf5/0x210 21:44:04 ...: [ 482.520547] [<ffffffff811454b5>] fput+0x25/0x30 21:44:04 ...: [ 482.520554] [<ffffffff811415ad>] filp_close+0x5d/0x90 21:44:04 ...: [ 482.520560] [<ffffffff81141697>] sys_close+0xb7/0x120 21:44:04 ...: [ 482.520568] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:44:04 ...: [ 482.520574] INFO: task md0_reshape:2287 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520578] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520582] md0_reshape D ffff88003aee96f0 0 2287 2 0x00000000 21:44:04 ...: [ 482.520590] ffff88003cf05a70 0000000000000046 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520597] ffff88003aee9aa8 ffff88003cf05fd8 0000000000015bc0 ffff88003aee96f0 21:44:04 ...: [ 482.520605] 0000000000015bc0 ffff88003cf05fd8 0000000000015bc0 ffff88003aee9aa8 21:44:04 ...: [ 482.520612] Call Trace: 21:44:04 ...: [ 482.520623] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:44:04 ...: [ 482.520633] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:44:04 ...: [ 482.520643] [<ffffffffa0226f80>] reshape_request+0x4c0/0x9a0 [raid456] 21:44:04 ...: [ 482.520651] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:44:04 ...: [ 482.520661] [<ffffffffa022777a>] sync_request+0x31a/0x3a0 [raid456] 21:44:04 ...: [ 482.520668] [<ffffffff81052713>] ? __wake_up+0x53/0x70 21:44:04 ...: [ 482.520675] [<ffffffff814156b1>] md_do_sync+0x621/0xbb0 21:44:04 ...: [ 482.520685] [<ffffffff810387b9>] ? default_spin_lock_flags+0x9/0x10 21:44:04 ...: [ 482.520692] [<ffffffff8141640c>] md_thread+0x5c/0x130 21:44:04 ...: [ 482.520699] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:44:04 ...: [ 482.520705] [<ffffffff814163b0>] ? md_thread+0x0/0x130 21:44:04 ...: [ 482.520711] [<ffffffff81084416>] kthread+0x96/0xa0 21:44:04 ...: [ 482.520718] [<ffffffff810131ea>] child_rip+0xa/0x20 21:44:04 ...: [ 482.520725] [<ffffffff81084380>] ? kthread+0x0/0xa0 21:44:04 ...: [ 482.520730] [<ffffffff810131e0>] ? child_rip+0x0/0x20 21:44:04 ...: [ 482.520735] INFO: task mdadm:2288 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520739] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520743] mdadm D 0000000000000000 0 2288 1 0x00000000 21:44:04 ...: [ 482.520751] ffff88002cca9c18 0000000000000086 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520759] ffff88003aee83b8 ffff88002cca9fd8 0000000000015bc0 ffff88003aee8000 21:44:04 ...: [ 482.520767] 0000000000015bc0 ffff88002cca9fd8 0000000000015bc0 ffff88003aee83b8 21:44:04 ...: [ 482.520774] Call Trace: 21:44:04 ...: [ 482.520782] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:44:04 ...: [ 482.520790] [<ffffffff812a6d50>] ? exact_match+0x0/0x10 21:44:04 ...: [ 482.520797] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:44:04 ...: [ 482.520804] [<ffffffff811742c8>] __blkdev_get+0x68/0x3d0 21:44:04 ...: [ 482.520810] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:44:04 ...: [ 482.520816] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:44:04 ...: [ 482.520822] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:44:04 ...: [ 482.520829] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:44:04 ...: [ 482.520837] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:44:04 ...: [ 482.520843] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:44:04 ...: [ 482.520850] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:44:04 ...: [ 482.520857] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:44:04 ...: [ 482.520864] [<ffffffff810ff0e1>] ? lru_cache_add_lru+0x21/0x40 21:44:04 ...: [ 482.520871] [<ffffffff8111109c>] ? do_anonymous_page+0x11c/0x330 21:44:04 ...: [ 482.520878] [<ffffffff81115d5f>] ? handle_mm_fault+0x31f/0x3c0 21:44:04 ...: [ 482.520885] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:44:04 ...: [ 482.520891] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:44:04 ...: [ 482.520897] [<ffffffff811418b0>] sys_open+0x20/0x30 21:44:04 ...: [ 482.520905] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:46:04 ...: [ 602.520053] INFO: task mdadm:1937 blocked for more than 120 seconds. 21:46:04 ...: [ 602.520059] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:46:04 ...: [ 602.520065] mdadm D 00000000ffffffff 0 1937 1 0x00000000 21:46:04 ...: [ 602.520075] ffff88002ef4f5d8 0000000000000082 0000000000015bc0 0000000000015bc0 21:46:04 ...: [ 602.520084] ffff88002eb5b198 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5ade0 21:46:04 ...: [ 602.520091] 0000000000015bc0 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5b198 21:46:04 ...: [ 602.520099] Call Trace: 21:46:04 ...: [ 602.520127] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:46:04 ...: [ 602.520142] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:46:04 ...: [ 602.520153] [<ffffffffa0228413>] make_request+0x243/0x4b0 [raid456] 21:46:04 ...: [ 602.520162] [<ffffffffa0221a90>] ? release_stripe+0x50/0x70 [raid456] 21:46:04 ...: [ 602.520171] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:46:04 ...: [ 602.520180] [<ffffffff81414df0>] md_make_request+0xc0/0x130 21:46:04 ...: [ 602.520187] [<ffffffff81414df0>] ? md_make_request+0xc0/0x130 21:46:04 ...: [ 602.520197] [<ffffffff8129f8c1>] generic_make_request+0x1b1/0x4f0 21:46:04 ...: [ 602.520206] [<ffffffff810f6515>] ? mempool_alloc_slab+0x15/0x20 21:46:04 ...: [ 602.520215] [<ffffffff8116c2ec>] ? alloc_buffer_head+0x1c/0x60 21:46:04 ...: [ 602.520222] [<ffffffff8129fc80>] submit_bio+0x80/0x110 21:46:04 ...: [ 602.520229] [<ffffffff8116c849>] submit_bh+0xf9/0x140 21:46:04 ...: [ 602.520237] [<ffffffff8116f124>] block_read_full_page+0x274/0x3b0 21:46:04 ...: [ 602.520244] [<ffffffff81172c90>] ? blkdev_get_block+0x0/0x70 21:46:04 ...: [ 602.520252] [<ffffffff8110d875>] ? __inc_zone_page_state+0x35/0x40 21:46:04 ...: [ 602.520259] [<ffffffff810f46d8>] ? add_to_page_cache_locked+0xe8/0x160 21:46:04 ...: [ 602.520266] [<ffffffff81173d78>] blkdev_readpage+0x18/0x20 21:46:04 ...: [ 602.520273] [<ffffffff810f484b>] __read_cache_page+0x7b/0xe0 21:46:04 ...: [ 602.520279] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:46:04 ...: [ 602.520285] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:46:04 ...: [ 602.520292] [<ffffffff810f57dc>] do_read_cache_page+0x3c/0x120 21:46:04 ...: [ 602.520300] [<ffffffff810f5909>] read_cache_page_async+0x19/0x20 21:46:04 ...: [ 602.520306] [<ffffffff810f591e>] read_cache_page+0xe/0x20 21:46:04 ...: [ 602.520314] [<ffffffff811a6cb0>] read_dev_sector+0x30/0xa0 21:46:04 ...: [ 602.520321] [<ffffffff811a7fcd>] amiga_partition+0x6d/0x460 21:46:04 ...: [ 602.520328] [<ffffffff811a7938>] check_partition+0x138/0x190 21:46:04 ...: [ 602.520335] [<ffffffff811a7a7a>] rescan_partitions+0xea/0x2f0 21:46:04 ...: [ 602.520342] [<ffffffff811744c7>] __blkdev_get+0x267/0x3d0 21:46:04 ...: [ 602.520348] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:46:04 ...: [ 602.520354] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:46:04 ...: [ 602.520359] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:46:04 ...: [ 602.520367] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:46:04 ...: [ 602.520375] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:46:04 ...: [ 602.520383] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:46:04 ...: [ 602.520390] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:46:04 ...: [ 602.520397] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:46:04 ...: [ 602.520404] [<ffffffff811134a8>] ? unmap_vmas+0x178/0x310 21:46:04 ...: [ 602.520413] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:46:04 ...: [ 602.520419] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:46:04 ...: [ 602.520425] [<ffffffff811418b0>] sys_open+0x20/0x30 21:46:04 ...: [ 602.520434] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:46:04 ...: [ 602.520443] INFO: task mdadm:2283 blocked for more than 120 seconds. 21:46:04 ...: [ 602.520447] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:46:04 ...: [ 602.520451] mdadm D 0000000000000000 0 2283 2212 0x00000000 21:46:04 ...: [ 602.520460] ffff88002cca7d98 0000000000000086 0000000000015bc0 0000000000015bc0 21:46:04 ...: [ 602.520468] ffff88002ededf78 ffff88002cca7fd8 0000000000015bc0 ffff88002ededbc0 21:46:04 ...: [ 602.520475] 0000000000015bc0 ffff88002cca7fd8 0000000000015bc0 ffff88002ededf78 21:46:04 ...: [ 602.520483] Call Trace: 21:46:04 ...: [ 602.520492] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:46:04 ...: [ 602.520500] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:46:04 ...: [ 602.520506] [<ffffffff8117404d>] __blkdev_put+0x3d/0x190 21:46:04 ...: [ 602.520512] [<ffffffff811741b0>] blkdev_put+0x10/0x20 21:46:04 ...: [ 602.520518] [<ffffffff811741f3>] blkdev_close+0x33/0x60 21:46:04 ...: [ 602.520526] [<ffffffff81145375>] __fput+0xf5/0x210 21:46:04 ...: [ 602.520533] [<ffffffff811454b5>] fput+0x25/0x30 21:46:04 ...: [ 602.520539] [<ffffffff811415ad>] filp_close+0x5d/0x90 21:46:04 ...: [ 602.520545] [<ffffffff81141697>] sys_close+0xb7/0x120 21:46:04 ...: [ 602.520552] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b

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• OpenVPN - Windows 8 to Windows 2008 Server, not connecting

  - by niico

  I have followed this tutorial about setting up an OpenVPN Server on Windows Server - and a client on Windows (in this case Windows 8). The server appears to be running fine - but it is not connecting with this error: Mon Jul 22 19:09:04 2013 Warning: cannot open --log file: C:\Program Files\OpenVPN\log\my-laptop.log: Access is denied. (errno=5) Mon Jul 22 19:09:04 2013 OpenVPN 2.3.2 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [PKCS11] [eurephia] [IPv6] built on Jun 3 2013 Mon Jul 22 19:09:04 2013 MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25340 Mon Jul 22 19:09:04 2013 Need hold release from management interface, waiting... Mon Jul 22 19:09:05 2013 MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25340 Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'state on' Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'log all on' Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'hold off' Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'hold release' Mon Jul 22 19:09:05 2013 Socket Buffers: R=[65536->65536] S=[65536->65536] Mon Jul 22 19:09:05 2013 UDPv4 link local: [undef] Mon Jul 22 19:09:05 2013 UDPv4 link remote: [AF_INET]66.666.66.666:9999 Mon Jul 22 19:09:05 2013 MANAGEMENT: >STATE:1374494945,WAIT,,, Mon Jul 22 19:10:05 2013 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity) Mon Jul 22 19:10:05 2013 TLS Error: TLS handshake failed Mon Jul 22 19:10:05 2013 SIGUSR1[soft,tls-error] received, process restarting Mon Jul 22 19:10:05 2013 MANAGEMENT: >STATE:1374495005,RECONNECTING,tls-error,, Mon Jul 22 19:10:05 2013 Restart pause, 2 second(s) Note I have changed the IP and port no (it uses a non-standard port for security reasons). That port is open on the hardware firewall. The server logs are showing a connection attempt from my client: TLS: Initial packet from [AF_INET]118.68.xx.xx:65011, sid=081af4ed xxxxxxxx Mon Jul 22 14:19:15 2013 118.68.xx.xx:65011 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity) How can I problem solve this & find the problem? Thx Update - Client config file: ############################################## # Sample client-side OpenVPN 2.0 config file # # for connecting to multi-client server. # # # # This configuration can be used by multiple # # clients, however each client should have # # its own cert and key files. # # # # On Windows, you might want to rename this # # file so it has a .ovpn extension # ############################################## # Specify that we are a client and that we # will be pulling certain config file directives # from the server. client # Use the same setting as you are using on # the server. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel # if you have more than one. On XP SP2, # you may need to disable the firewall # for the TAP adapter. ;dev-node MyTap # Are we connecting to a TCP or # UDP server? Use the same setting as # on the server. ;proto tcp proto udp # The hostname/IP and port of the server. # You can have multiple remote entries # to load balance between the servers. remote 00.00.00.00 1194 ;remote 00.00.00.00 9999 ;remote my-server-2 1194 # Choose a random host from the remote # list for load-balancing. Otherwise # try hosts in the order specified. ;remote-random # Keep trying indefinitely to resolve the # host name of the OpenVPN server. Very useful # on machines which are not permanently connected # to the internet such as laptops. resolv-retry infinite # Most clients don't need to bind to # a specific local port number. nobind # Downgrade privileges after initialization (non-Windows only) ;user nobody ;group nobody # Try to preserve some state across restarts. persist-key persist-tun # If you are connecting through an # HTTP proxy to reach the actual OpenVPN # server, put the proxy server/IP and # port number here. See the man page # if your proxy server requires # authentication. ;http-proxy-retry # retry on connection failures ;http-proxy [proxy server] [proxy port #] # Wireless networks often produce a lot # of duplicate packets. Set this flag # to silence duplicate packet warnings. ;mute-replay-warnings # SSL/TLS parms. # See the server config file for more # description. It's best to use # a separate .crt/.key file pair # for each client. A single ca # file can be used for all clients. ca "C:\\Program Files\\OpenVPN\\config\\ca.crt" cert "C:\\Program Files\\OpenVPN\\config\\my-laptop.crt" key "C:\\Program Files\\OpenVPN\\config\\my-laptop.key" # Verify server certificate by checking # that the certicate has the nsCertType # field set to "server". This is an # important precaution to protect against # a potential attack discussed here: # http://openvpn.net/howto.html#mitm # # To use this feature, you will need to generate # your server certificates with the nsCertType # field set to "server". The build-key-server # script in the easy-rsa folder will do this. ns-cert-type server # If a tls-auth key is used on the server # then every client must also have the key. ;tls-auth ta.key 1 # Select a cryptographic cipher. # If the cipher option is used on the server # then you must also specify it here. ;cipher x # Enable compression on the VPN link. # Don't enable this unless it is also # enabled in the server config file. comp-lzo # Set log file verbosity. verb 3 # Silence repeating messages ;mute 20 Server config file: ################################################# # Sample OpenVPN 2.0 config file for # # multi-client server. # # # # This file is for the server side # # of a many-clients <-> one-server # # OpenVPN configuration. # # # # OpenVPN also supports # # single-machine <-> single-machine # # configurations (See the Examples page # # on the web site for more info). # # # # This config should work on Windows # # or Linux/BSD systems. Remember on # # Windows to quote pathnames and use # # double backslashes, e.g.: # # "C:\\Program Files\\OpenVPN\\config\\foo.key" # # # # Comments are preceded with '#' or ';' # ################################################# # Which local IP address should OpenVPN # listen on? (optional) ;local 00.00.00.00 # Which TCP/UDP port should OpenVPN listen on? # If you want to run multiple OpenVPN instances # on the same machine, use a different port # number for each one. You will need to # open up this port on your firewall. std 1194 port 1194 # TCP or UDP server? ;proto tcp proto udp # "dev tun" will create a routed IP tunnel, # "dev tap" will create an ethernet tunnel. # Use "dev tap0" if you are ethernet bridging # and have precreated a tap0 virtual interface # and bridged it with your ethernet interface. # If you want to control access policies # over the VPN, you must create firewall # rules for the the TUN/TAP interface. # On non-Windows systems, you can give # an explicit unit number, such as tun0. # On Windows, use "dev-node" for this. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel if you # have more than one. On XP SP2 or higher, # you may need to selectively disable the # Windows firewall for the TAP adapter. # Non-Windows systems usually don't need this. ;dev-node MyTap # SSL/TLS root certificate (ca), certificate # (cert), and private key (key). Each client # and the server must have their own cert and # key file. The server and all clients will # use the same ca file. # # See the "easy-rsa" directory for a series # of scripts for generating RSA certificates # and private keys. Remember to use # a unique Common Name for the server # and each of the client certificates. # # Any X509 key management system can be used. # OpenVPN can also use a PKCS #12 formatted key file # (see "pkcs12" directive in man page). ca "C:\\Program Files\\OpenVPN\\config\\ca.crt" cert "C:\\Program Files\\OpenVPN\\config\\server.crt" key "C:\\Program Files\\OpenVPN\\config\\server.key" # Diffie hellman parameters. # Generate your own with: # openssl dhparam -out dh1024.pem 1024 # Substitute 2048 for 1024 if you are using # 2048 bit keys. dh "C:\\Program Files\\OpenVPN\\config\\dh2048.pem" # Configure server mode and supply a VPN subnet # for OpenVPN to draw client addresses from. # The server will take 10.8.0.1 for itself, # the rest will be made available to clients. # Each client will be able to reach the server # on 10.8.0.1. Comment this line out if you are # ethernet bridging. See the man page for more info. server 10.8.0.0 255.255.255.0 # Maintain a record of client <-> virtual IP address # associations in this file. If OpenVPN goes down or # is restarted, reconnecting clients can be assigned # the same virtual IP address from the pool that was # previously assigned. ifconfig-pool-persist ipp.txt # Configure server mode for ethernet bridging. # You must first use your OS's bridging capability # to bridge the TAP interface with the ethernet # NIC interface. Then you must manually set the # IP/netmask on the bridge interface, here we # assume 10.8.0.4/255.255.255.0. Finally we # must set aside an IP range in this subnet # (start=10.8.0.50 end=10.8.0.100) to allocate # to connecting clients. Leave this line commented # out unless you are ethernet bridging. ;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100 # Configure server mode for ethernet bridging # using a DHCP-proxy, where clients talk # to the OpenVPN server-side DHCP server # to receive their IP address allocation # and DNS server addresses. You must first use # your OS's bridging capability to bridge the TAP # interface with the ethernet NIC interface. # Note: this mode only works on clients (such as # Windows), where the client-side TAP adapter is # bound to a DHCP client. ;server-bridge # Push routes to the client to allow it # to reach other private subnets behind # the server. Remember that these # private subnets will also need # to know to route the OpenVPN client # address pool (10.8.0.0/255.255.255.0) # back to the OpenVPN server. ;push "route 192.168.10.0 255.255.255.0" ;push "route 192.168.20.0 255.255.255.0" # To assign specific IP addresses to specific # clients or if a connecting client has a private # subnet behind it that should also have VPN access, # use the subdirectory "ccd" for client-specific # configuration files (see man page for more info). # EXAMPLE: Suppose the client # having the certificate common name "Thelonious" # also has a small subnet behind his connecting # machine, such as 192.168.40.128/255.255.255.248. # First, uncomment out these lines: ;client-config-dir ccd ;route 192.168.40.128 255.255.255.248 # Then create a file ccd/Thelonious with this line: # iroute 192.168.40.128 255.255.255.248 # This will allow Thelonious' private subnet to # access the VPN. This example will only work # if you are routing, not bridging, i.e. you are # using "dev tun" and "server" directives. # EXAMPLE: Suppose you want to give # Thelonious a fixed VPN IP address of 10.9.0.1. # First uncomment out these lines: ;client-config-dir ccd ;route 10.9.0.0 255.255.255.252 # Then add this line to ccd/Thelonious: # ifconfig-push 10.9.0.1 10.9.0.2 # Suppose that you want to enable different # firewall access policies for different groups # of clients. There are two methods: # (1) Run multiple OpenVPN daemons, one for each # group, and firewall the TUN/TAP interface # for each group/daemon appropriately. # (2) (Advanced) Create a script to dynamically # modify the firewall in response to access # from different clients. See man # page for more info on learn-address script. ;learn-address ./script # If enabled, this directive will configure # all clients to redirect their default # network gateway through the VPN, causing # all IP traffic such as web browsing and # and DNS lookups to go through the VPN # (The OpenVPN server machine may need to NAT # or bridge the TUN/TAP interface to the internet # in order for this to work properly). ;push "redirect-gateway def1 bypass-dhcp" # Certain Windows-specific network settings # can be pushed to clients, such as DNS # or WINS server addresses. CAVEAT: # http://openvpn.net/faq.html#dhcpcaveats # The addresses below refer to the public # DNS servers provided by opendns.com. ;push "dhcp-option DNS 208.67.222.222" ;push "dhcp-option DNS 208.67.220.220" # Uncomment this directive to allow differenta # clients to be able to "see" each other. # By default, clients will only see the server. # To force clients to only see the server, you # will also need to appropriately firewall the # server's TUN/TAP interface. ;client-to-client # Uncomment this directive if multiple clients # might connect with the same certificate/key # files or common names. This is recommended # only for testing purposes. For production use, # each client should have its own certificate/key # pair. # # IF YOU HAVE NOT GENERATED INDIVIDUAL # CERTIFICATE/KEY PAIRS FOR EACH CLIENT, # EACH HAVING ITS OWN UNIQUE "COMMON NAME", # UNCOMMENT THIS LINE OUT. ;duplicate-cn # The keepalive directive causes ping-like # messages to be sent back and forth over # the link so that each side knows when # the other side has gone down. # Ping every 10 seconds, assume that remote # peer is down if no ping received during # a 120 second time period. keepalive 10 120 # For extra security beyond that provided # by SSL/TLS, create an "HMAC firewall" # to help block DoS attacks and UDP port flooding. # # Generate with: # openvpn --genkey --secret ta.key # # The server and each client must have # a copy of this key. # The second parameter should be '0' # on the server and '1' on the clients. ;tls-auth ta.key 0 # This file is secret # Select a cryptographic cipher. # This config item must be copied to # the client config file as well. ;cipher BF-CBC # Blowfish (default) ;cipher AES-128-CBC # AES ;cipher DES-EDE3-CBC # Triple-DES # Enable compression on the VPN link. # If you enable it here, you must also # enable it in the client config file. comp-lzo # The maximum number of concurrently connected # clients we want to allow. ;max-clients 100 # It's a good idea to reduce the OpenVPN # daemon's privileges after initialization. # # You can uncomment this out on # non-Windows systems. ;user nobody ;group nobody # The persist options will try to avoid # accessing certain resources on restart # that may no longer be accessible because # of the privilege downgrade. persist-key persist-tun # Output a short status file showing # current connections, truncated # and rewritten every minute. status openvpn-status.log # By default, log messages will go to the syslog (or # on Windows, if running as a service, they will go to # the "\Program Files\OpenVPN\log" directory). # Use log or log-append to override this default. # "log" will truncate the log file on OpenVPN startup, # while "log-append" will append to it. Use one # or the other (but not both). ;log openvpn.log ;log-append openvpn.log # Set the appropriate level of log # file verbosity. # # 0 is silent, except for fatal errors # 4 is reasonable for general usage # 5 and 6 can help to debug connection problems # 9 is extremely verbose verb 3 # Silence repeating messages. At most 20 # sequential messages of the same message # category will be output to the log. ;mute 20 I have changed IP's for security

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• Configuring ELMAH: Unrecognized config section error

  - by Zian Choy

  Setup: Windows XP .NET Framework 3.5 SP1 ASP .NET MVC Version 1 I've been trying to set up ELMAH by following the instructions at http://code.google.com/p/elmah/wiki/MVC but I just get the following error when press F5: Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately. Parser Error Message: Unrecognized configuration section elmah/errorlog. Source Error: Line 30: Line 31: <elmah> Line 32: <errorlog type="Elmah.XmlFilerErrorLog, Elmah" logPath="~/App_Data" /> Line 33: </elmah> Line 34: And, here's the configuration file: <?xml version="1.0"?> <!-- Note: As an alternative to hand editing this file you can use the web admin tool to configure settings for your application. Use the Website->Asp.Net Configuration option in Visual Studio. A full list of settings and comments can be found in machine.config.comments usually located in \Windows\Microsoft.Net\Framework\v2.x\Config --> <configuration> <configSections> <sectionGroup name="elmah"> <section name="security" type="Elmah.SecuritySectionHandler, Elmah"/> <section name="errorLog" type="Elmah.ErrorLogSectionHandler, Elmah"/> <section name="errorMail" type="Elmah.ErrorMailSectionHandler, Elmah"/> <section name="errorFilter" type="Elmah.ErrorFilterSectionHandler, Elmah"/> </sectionGroup> <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"> <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"> <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/> <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"> <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/> <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/> <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/> <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/> </sectionGroup> </sectionGroup> </sectionGroup> </configSections> <elmah> <errorlog type="Elmah.XmlFilerErrorLog, Elmah" logPath="~/App_Data" /> </elmah> <appSettings/> <connectionStrings> <add name="ApplicationServices" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient"/> </connectionStrings> <system.web> <!-- Set compilation debug="true" to insert debugging symbols into the compiled page. Because this affects performance, set this value to true only during development. --> <compilation debug="true"> <assemblies> <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/> <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add assembly="System.Web.Abstractions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add assembly="System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add assembly="System.Web.Mvc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/> <add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/> <add assembly="System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/> </assemblies> </compilation> <!-- The <authentication> section enables configuration of the security authentication mode used by ASP.NET to identify an incoming user. --> <authentication mode="Forms"> <forms loginUrl="~/Account/LogOn" timeout="2880"/> </authentication> <membership> <providers> <clear/> <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" connectionStringName="ApplicationServices" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" passwordFormat="Hashed" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" passwordStrengthRegularExpression="" applicationName="/"/> </providers> </membership> <profile> <providers> <clear/> <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" connectionStringName="ApplicationServices" applicationName="/"/> </providers> </profile> <roleManager enabled="false"> <providers> <clear/> <add connectionStringName="ApplicationServices" applicationName="/" name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/> <add applicationName="/" name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/> </providers> </roleManager> <!-- The <customErrors> section enables configuration of what to do if/when an unhandled error occurs during the execution of a request. Specifically, it enables developers to configure html error pages to be displayed in place of a error stack trace. <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm"> <error statusCode="403" redirect="NoAccess.htm" /> <error statusCode="404" redirect="FileNotFound.htm" /> </customErrors> --> <pages> <controls> <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> </controls> <namespaces> <add namespace="System.Web.Mvc"/> <add namespace="System.Web.Mvc.Ajax"/> <add namespace="System.Web.Mvc.Html"/> <add namespace="System.Web.Routing"/> <add namespace="System.Linq"/> <add namespace="System.Collections.Generic"/> </namespaces> </pages> <httpHandlers> <remove verb="*" path="*.asmx"/> <add verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah"/> <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/> <add verb="*" path="*.mvc" validate="false" type="System.Web.Mvc.MvcHttpHandler, System.Web.Mvc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> </httpHandlers> <httpModules> <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah"/> <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> </httpModules> </system.web> <system.codedom> <compilers> <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"> <providerOption name="CompilerVersion" value="v3.5"/> <providerOption name="WarnAsError" value="false"/> </compiler> <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" warningLevel="4" type="Microsoft.VisualBasic.VBCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"> <providerOption name="CompilerVersion" value="v3.5"/> <providerOption name="OptionInfer" value="true"/> <providerOption name="WarnAsError" value="false"/> </compiler> </compilers> </system.codedom> <system.web.extensions/> <system.webServer> <validation validateIntegratedModeConfiguration="false"/> <modules runAllManagedModulesForAllRequests="true"> <remove name="ScriptModule"/> <remove name="UrlRoutingModule"/> <add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> </modules> <handlers> <remove name="WebServiceHandlerFactory-Integrated"/> <remove name="ScriptHandlerFactory"/> <remove name="ScriptHandlerFactoryAppServices"/> <remove name="ScriptResource"/> <remove name="MvcHttpHandler"/> <remove name="UrlRoutingHandler"/> <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="MvcHttpHandler" preCondition="integratedMode" verb="*" path="*.mvc" type="System.Web.Mvc.MvcHttpHandler, System.Web.Mvc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="UrlRoutingHandler" preCondition="integratedMode" verb="*" path="UrlRouting.axd" type="System.Web.HttpForbiddenHandler, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/> </handlers> </system.webServer> </configuration> Edit Solved The following block should have gone after </system.webServer> and before </configuration> <elmah> <errorlog type="Elmah.XmlFilerErrorLog, Elmah" logPath="~/App_Data" /> </elmah>

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• Repaint() not calling paint() in Java

  - by Joshua Auriemma

  Let me start off by saying I know I've violated some basic Java principles in this messy code, but I'm desperately trying to finish a program by Tuesday for a social science experiment, and I don't know Java, so I'm basically just fumbling through it for now. With that disclaimer out of the way, I have a separate program working where a circle is moving around the screen and the user must click on it. It works fine when its in its own separate class file, but when I add the code to my main program, it's no longer working. I don't even really understand why repaint() calls my paint() function — as far as I'm concerned, it's magic, but I've noticed that repaint() calls paint() in my test program, but not in the more complicated actual program, and I assume that's why the circle is no longer painting on my program. Entire code is below: import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import javax.swing.*; import java.awt.event.*; import java.awt.geom.Ellipse2D; import java.io.FileReader; import java.io.IOException; import java.util.Calendar; public class Reflexology1 extends JFrame{ private static final long serialVersionUID = -1295261024563143679L; private Ellipse2D ball = new Ellipse2D.Double(0, 0, 25, 25); private Timer moveBallTimer; int _ballXpos, _ballYpos; JButton button1, button2; JButton movingButton; JTextArea textArea1; int buttonAClicked, buttonDClicked; private long _openTime = 0; private long _closeTime = 0; JPanel thePanel = new JPanel(); JPanel thePlacebo = new JPanel(); final JFrame frame = new JFrame("Reflexology"); final JFrame frame2 = new JFrame("The Test"); JLabel label1 = new JLabel("Press X and then click the moving dot as fast as you can."); public static void main(String[] args){ new Reflexology1(); } public Reflexology1(){ frame.setSize(600, 475); frame.setLocationRelativeTo(null); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setTitle("Reflexology 1.0"); frame.setResizable(false); frame2.setSize(600, 475); frame2.setLocationRelativeTo(null); frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame2.setTitle("Reflexology 1.0"); frame2.setResizable(false); button1 = new JButton("Accept"); button2 = new JButton("Decline"); //movingButton = new JButton("Click Me"); ListenForAcceptButton lForAButton = new ListenForAcceptButton(); ListenForDeclineButton lForDButton = new ListenForDeclineButton(); button1.addActionListener(lForAButton); button2.addActionListener(lForDButton); //movingButton.addActionListener(lForMButton); JTextArea textArea1 = new JTextArea(24, 50); textArea1.setText("Tracking Events\n"); textArea1.setLineWrap(true); textArea1.setWrapStyleWord(true); textArea1.setSize(15, 50); textArea1.setEditable(false); FileReader reader = null; try { reader = new FileReader("EULA.txt"); textArea1.read(reader, "EULA.txt"); } catch (IOException exception) { System.err.println("Problem loading file"); exception.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException exception) { System.err.println("Error closing reader"); exception.printStackTrace(); } } } JScrollPane scrollBar1 = new JScrollPane(textArea1, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); AdjustmentListener listener = new MyAdjustmentListener(); thePanel.add(scrollBar1); thePanel.add(button1); thePanel.add(button2); frame.add(thePanel); ListenForMouse lForMouse = new ListenForMouse(); thePlacebo.addMouseListener(lForMouse); thePlacebo.add(label1); frame2.add(thePlacebo); ListenForWindow lForWindow = new ListenForWindow(); frame.addWindowListener(lForWindow); frame2.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e){ if(e.getKeyChar() == 'X' || e.getKeyChar() == 'x') {moveBallTimer.start();} } }); frame.setVisible(true); moveBallTimer = new Timer(1000, new ActionListener() { public void actionPerformed(ActionEvent e) { moveBall(); System.out.println("Timer started!"); repaint(); } }); addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { if(frame2.isVisible()){ moveBallTimer.start(); } } }); } private class ListenForAcceptButton implements ActionListener{ public void actionPerformed(ActionEvent e){ if (e.getSource() == button1){ Calendar ClCDateTime = Calendar.getInstance(); System.out.println(ClCDateTime.getTimeInMillis() - _openTime); _closeTime = ClCDateTime.getTimeInMillis() - _openTime; //frame.getContentPane().remove(thePanel); //thePlacebo.addKeyListener(lForKeys); //frame.getContentPane().add(thePlacebo); //frame.repaint(); //moveBallTimer.start(); frame.setVisible(false); frame2.setVisible(true); frame2.revalidate(); frame2.repaint(); } } } private class ListenForDeclineButton implements ActionListener{ public void actionPerformed(ActionEvent e){ if (e.getSource() == button2){ JOptionPane.showMessageDialog(Reflexology1.this, "You've declined the license agreement. DO NOT RESTART the program. Please go inform a researcher that you have declined the agreement.", "WARNING", JOptionPane.INFORMATION_MESSAGE); System.exit(0); } } } private class ListenForWindow implements WindowListener{ public void windowActivated(WindowEvent e) { //textArea1.append("Window is active"); } // if this.dispose() is called, this is called: public void windowClosed(WindowEvent arg0) { } // When a window is closed from a menu, this is called: public void windowClosing(WindowEvent arg0) { } // Called when the window is no longer the active window: public void windowDeactivated(WindowEvent arg0) { //textArea1.append("Window is NOT active"); } // Window gone from minimized to normal state public void windowDeiconified(WindowEvent arg0) { //textArea1.append("Window is in normal state"); } // Window has been minimized public void windowIconified(WindowEvent arg0) { //textArea1.append("Window is minimized"); } // Called when the Window is originally created public void windowOpened(WindowEvent arg0) { //textArea1.append("Let there be Window!"); Calendar OlCDateTime = Calendar.getInstance(); _openTime = OlCDateTime.getTimeInMillis(); //System.out.println(_openTime); } } private class MyAdjustmentListener implements AdjustmentListener { public void adjustmentValueChanged(AdjustmentEvent arg0) { AdjustmentEvent scrollBar1; //System.out.println(scrollBar1.getValue())); } } public void paint(Graphics g) { //super.paint(g); frame2.paint(g); Graphics2D g2d = (Graphics2D) g; g2d.setColor(Color.RED); g2d.fill(ball); System.out.println("Calling fill()"); } protected void moveBall() { //System.out.println("I'm in the moveBall() function!"); int width = getWidth(); int height = getHeight(); int min, max, randomX, randomY; min =200; max = -200; randomX = min + (int)(Math.random() * ((max - min)+1)); randomY = min + (int)(Math.random() * ((max - min)+1)); //System.out.println(randomX + ", " + randomY); Rectangle ballBounds = ball.getBounds(); //System.out.println(ballBounds.x + ", " + ballBounds.y); if (ballBounds.x + randomX < 0) { randomX = 200; } else if (ballBounds.x + ballBounds.width + randomX > width) { randomX = -200; } if (ballBounds.y + randomY < 0) { randomY = 200; } else if (ballBounds.y + ballBounds.height + randomY > height) { randomY = -200; } ballBounds.x += randomX; ballBounds.y += randomY; _ballXpos = ballBounds.x; _ballYpos = ballBounds.y; ball.setFrame(ballBounds); } public void start() { moveBallTimer.start(); } public void stop() { moveBallTimer.stop(); } private class ListenForMouse implements MouseListener{ // Called when the mouse is clicked public void mouseClicked(MouseEvent e) { //System.out.println("Mouse Panel pos: " + e.getX() + " " + e.getY() + "\n"); if (e.getX() >=_ballXpos && e.getX() <= _ballXpos + 25 && e.getY() <=_ballYpos && e.getY() >= _ballYpos - 25 ) { System.out.println("TRUE"); } System.out.println("{e.getX(): " + e.getX() + " / " + "_ballXpos: " + _ballXpos + " | " + "{e.getY(): " + e.getY() + " / " + "_ballYpos: " + _ballYpos); } public void mouseEntered(MouseEvent arg0) { // TODO Auto-generated method stub } public void mouseExited(MouseEvent arg0) { // TODO Auto-generated method stub } public void mousePressed(MouseEvent arg0) { // TODO Auto-generated method stub } public void mouseReleased(MouseEvent arg0) { // TODO Auto-generated method stub } } // System.out.println("e.getX(): " + e.getX() + " / " + "_ballXpos: " + _ballXpos); // Mouse over public void mouseEntered(MouseEvent arg0) { // TODO Auto-generated method stub } // Mouse left the mouseover area: public void mouseExited(MouseEvent arg0) { // TODO Auto-generated method stub } public void mousePressed(MouseEvent arg0) { // TODO Auto-generated method stub } public void mouseReleased(MouseEvent arg0) { // TODO Auto-generated method stub } } Could anyone tell me what I need to do to get repaint() to call the paint() method in the above program? I'm assuming the multiple frames is causing the problem, but that's just a guess. Thanks.

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• Process is killed without a (obvious) reason and program stops working

  - by Krzysiek Gurniak

  Here's what my program is supposed to do: create 4 child processes: process 0 is reading 1 byte at a time from STDIN, then writing it into FIFO process 1 is reading this 1 byte from fifo and write its value as HEX into shared memory process 2 is reading HEX value from shared memory and writing it into pipe finally process 3 is reading from pipe and writing into STDOUT (in my case: terminal) I can't change communication channels. FIFO, then shared memory, then pipes are the only option. My problem: Program stops at random moments when some file is directed into stdin (for example:./program < /dev/urandom). Sometimes after writing 5 HEX values, sometimes after 100. Weird thing is that when it is working and in another terminal I write "pstree -c" there is 1 main process with 4 children processes (which is what I want), but when I write "pstree -c" after it stopped writing (but still runs) there are only 3 child processes. For some reason 1 is gone even though they all have while(1) in them.. I think I might have problem with synchronization here, but I am unable to spot it (I've tried for many hours). Here's the code: #include <unistd.h> #include <fcntl.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <sys/shm.h> #include <sys/sem.h> #include <sys/types.h> #include <sys/wait.h> #include <sys/stat.h> #include <string.h> #include <signal.h> #define BUFSIZE 1 #define R 0 #define W 1 // processes ID pid_t p0, p1, p2, p3; // FIFO variables int fifo_fd; unsigned char bufor[BUFSIZE] = {}; unsigned char bufor1[BUFSIZE] = {}; // Shared memory variables key_t key; int shmid; char * tab; // zmienne do pipes int file_des[2]; char bufor_pipe[BUFSIZE*30] = {}; void proces0() { ssize_t n; while(1) { fifo_fd = open("/tmp/fifo",O_WRONLY); if(fifo_fd == -1) { perror("blad przy otwieraniu kolejki FIFO w p0\n"); exit(1); } n = read(STDIN_FILENO, bufor, BUFSIZE); if(n<0) { perror("read error w p0\n"); exit(1); } if(n > 0) { if(write(fifo_fd, bufor, n) != n) { perror("blad zapisu do kolejki fifo w p0\n"); exit(1); } memset(bufor, 0, n); // czyszczenie bufora } close(fifo_fd); } } void proces1() { ssize_t m, x; char wartosc_hex[30] = {}; while(1) { if(tab[0] == 0) { fifo_fd = open("/tmp/fifo", O_RDONLY); // otwiera plik typu fifo do odczytu if(fifo_fd == -1) { perror("blad przy otwieraniu kolejki FIFO w p1\n"); exit(1); } m = read(fifo_fd, bufor1, BUFSIZE); x = m; if(x < 0) { perror("read error p1\n"); exit(1); } if(x > 0) { // Konwersja na HEX if(bufor1[0] < 16) { if(bufor1[0] == 10) // gdy enter { sprintf(wartosc_hex, "0x0%X\n", bufor1[0]); } else { sprintf(wartosc_hex, "0x0%X ", bufor1[0]); } } else { sprintf(wartosc_hex, "0x%X ", bufor1[0]); } // poczekaj az pamiec bedzie pusta (gotowa do zapisu) strcpy(&tab[0], wartosc_hex); memset(bufor1, 0, sizeof(bufor1)); // czyszczenie bufora memset(wartosc_hex, 0, sizeof(wartosc_hex)); // przygotowanie tablicy na zapis wartosci hex x = 0; } close(fifo_fd); } } } void proces2() { close(file_des[0]); // zablokuj kanal do odczytu while(1) { if(tab[0] != 0) { if(write(file_des[1], tab, strlen(tab)) != strlen(tab)) { perror("blad write w p2"); exit(1); } // wyczysc pamiec dzielona by przyjac kolejny bajt memset(tab, 0, sizeof(tab)); } } } void proces3() { ssize_t n; close(file_des[1]); // zablokuj kanal do zapisu while(1) { if(tab[0] == 0) { if((n = read(file_des[0], bufor_pipe, sizeof(bufor_pipe))) > 0) { if(write(STDOUT_FILENO, bufor_pipe, n) != n) { perror("write error w proces3()"); exit(1); } memset(bufor_pipe, 0, sizeof(bufor_pipe)); } } } } int main(void) { key = 5678; int status; // Tworzenie plikow przechowujacych ID procesow int des_pid[2] = {}; char bufor_proces[50] = {}; mknod("pid0", S_IFREG | 0777, 0); mknod("pid1", S_IFREG | 0777, 0); mknod("pid2", S_IFREG | 0777, 0); mknod("pid3", S_IFREG | 0777, 0); // Tworzenie semaforow key_t klucz; klucz = ftok(".", 'a'); // na podstawie pliku i pojedynczego znaku id wyznacza klucz semafora if(klucz == -1) { perror("blad wyznaczania klucza semafora"); exit(1); } semafor = semget(klucz, 1, IPC_CREAT | 0777); // tworzy na podstawie klucza semafor. 1 - ilosc semaforow if(semafor == -1) { perror("blad przy tworzeniu semafora"); exit(1); } if(semctl(semafor, 0, SETVAL, 0) == -1) // ustawia poczatkowa wartosc semafora (klucz, numer w zbiorze od 0, polecenie, argument 0/1/2) { perror("blad przy ustawianiu wartosci poczatkowej semafora"); exit(1); } // Tworzenie lacza nazwanego FIFO if(access("/tmp/fifo", F_OK) == -1) // sprawdza czy plik istnieje, jesli nie - tworzy go { if(mkfifo("/tmp/fifo", 0777) != 0) { perror("blad tworzenia FIFO w main"); exit(1); } } // Tworzenie pamieci dzielonej // Lista pamieci wspoldzielonych, komenda "ipcs" // usuwanie pamieci wspoldzielonej, komenta "ipcrm -m ID_PAMIECI" shmid = shmget(key, (BUFSIZE*30), 0666 | IPC_CREAT); if(shmid == -1) { perror("shmget"); exit(1); } tab = (char *) shmat(shmid, NULL, 0); if(tab == (char *)(-1)) { perror("shmat"); exit(1); } memset(tab, 0, (BUFSIZE*30)); // Tworzenie lacza nienazwanego pipe if(pipe(file_des) == -1) { perror("pipe"); exit(1); } // Tworzenie procesow potomnych if(!(p0 = fork())) { des_pid[W] = open("pid0", O_WRONLY | O_TRUNC | O_CREAT); // 1 - zapis, 0 - odczyt sprintf(bufor_proces, "Proces0 ma ID: %d\n", getpid()); if(write(des_pid[W], bufor_proces, sizeof(bufor_proces)) != sizeof(bufor_proces)) { perror("blad przy zapisie pid do pliku w p0"); exit(1); } close(des_pid[W]); proces0(); } else if(p0 == -1) { perror("blad przy p0 fork w main"); exit(1); } else { if(!(p1 = fork())) { des_pid[W] = open("pid1", O_WRONLY | O_TRUNC | O_CREAT); // 1 - zapis, 0 - odczyt sprintf(bufor_proces, "Proces1 ma ID: %d\n", getpid()); if(write(des_pid[W], bufor_proces, sizeof(bufor_proces)) != sizeof(bufor_proces)) { perror("blad przy zapisie pid do pliku w p1"); exit(1); } close(des_pid[W]); proces1(); } else if(p1 == -1) { perror("blad przy p1 fork w main"); exit(1); } else { if(!(p2 = fork())) { des_pid[W] = open("pid2", O_WRONLY | O_TRUNC | O_CREAT); // 1 - zapis, 0 - odczyt sprintf(bufor_proces, "Proces2 ma ID: %d\n", getpid()); if(write(des_pid[W], bufor_proces, sizeof(bufor_proces)) != sizeof(bufor_proces)) { perror("blad przy zapisie pid do pliku w p2"); exit(1); } close(des_pid[W]); proces2(); } else if(p2 == -1) { perror("blad przy p2 fork w main"); exit(1); } else { if(!(p3 = fork())) { des_pid[W] = open("pid3", O_WRONLY | O_TRUNC | O_CREAT); // 1 - zapis, 0 - odczyt sprintf(bufor_proces, "Proces3 ma ID: %d\n", getpid()); if(write(des_pid[W], bufor_proces, sizeof(bufor_proces)) != sizeof(bufor_proces)) { perror("blad przy zapisie pid do pliku w p3"); exit(1); } close(des_pid[W]); proces3(); } else if(p3 == -1) { perror("blad przy p3 fork w main"); exit(1); } else { // proces macierzysty waitpid(p0, &status, 0); waitpid(p1, &status, 0); waitpid(p2, &status, 0); waitpid(p3, &status, 0); //wait(NULL); unlink("/tmp/fifo"); shmdt(tab); // odlaczenie pamieci dzielonej shmctl(shmid, IPC_RMID, NULL); // usuwanie pamieci wspoldzielonej printf("\nKONIEC PROGRAMU\n"); } } } } exit(0); }

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• Zen and the Art of File and Folder Organization

  - by Mark Virtue

  Is your desk a paragon of neatness, or does it look like a paper-bomb has gone off? If you’ve been putting off getting organized because the task is too huge or daunting, or you don’t know where to start, we’ve got 40 tips to get you on the path to zen mastery of your filing system. For all those readers who would like to get their files and folders organized, or, if they’re already organized, better organized—we have compiled a complete guide to getting organized and staying organized, a comprehensive article that will hopefully cover every possible tip you could want. Signs that Your Computer is Poorly Organized If your computer is a mess, you’re probably already aware of it.  But just in case you’re not, here are some tell-tale signs: Your Desktop has over 40 icons on it “My Documents” contains over 300 files and 60 folders, including MP3s and digital photos You use the Windows’ built-in search facility whenever you need to find a file You can’t find programs in the out-of-control list of programs in your Start Menu You save all your Word documents in one folder, all your spreadsheets in a second folder, etc Any given file that you’re looking for may be in any one of four different sets of folders But before we start, here are some quick notes: We’re going to assume you know what files and folders are, and how to create, save, rename, copy and delete them The organization principles described in this article apply equally to all computer systems.  However, the screenshots here will reflect how things look on Windows (usually Windows 7).  We will also mention some useful features of Windows that can help you get organized. Everyone has their own favorite methodology of organizing and filing, and it’s all too easy to get into “My Way is Better than Your Way” arguments.  The reality is that there is no perfect way of getting things organized.  When I wrote this article, I tried to keep a generalist and objective viewpoint.  I consider myself to be unusually well organized (to the point of obsession, truth be told), and I’ve had 25 years experience in collecting and organizing files on computers.  So I’ve got a lot to say on the subject.  But the tips I have described here are only one way of doing it.  Hopefully some of these tips will work for you too, but please don’t read this as any sort of “right” way to do it. At the end of the article we’ll be asking you, the reader, for your own organization tips. Why Bother Organizing At All? For some, the answer to this question is self-evident. And yet, in this era of powerful desktop search software (the search capabilities built into the Windows Vista and Windows 7 Start Menus, and third-party programs like Google Desktop Search), the question does need to be asked, and answered. I have a friend who puts every file he ever creates, receives or downloads into his My Documents folder and doesn’t bother filing them into subfolders at all.  He relies on the search functionality built into his Windows operating system to help him find whatever he’s looking for.  And he always finds it.  He’s a Search Samurai.  For him, filing is a waste of valuable time that could be spent enjoying life! It’s tempting to follow suit.  On the face of it, why would anyone bother to take the time to organize their hard disk when such excellent search software is available?  Well, if all you ever want to do with the files you own is to locate and open them individually (for listening, editing, etc), then there’s no reason to ever bother doing one scrap of organization.  But consider these common tasks that are not achievable with desktop search software: Find files manually.  Often it’s not convenient, speedy or even possible to utilize your desktop search software to find what you want.  It doesn’t work 100% of the time, or you may not even have it installed.  Sometimes its just plain faster to go straight to the file you want, if you know it’s in a particular sub-folder, rather than trawling through hundreds of search results. Find groups of similar files (e.g. all your “work” files, all the photos of your Europe holiday in 2008, all your music videos, all the MP3s from Dark Side of the Moon, all your letters you wrote to your wife, all your tax returns).  Clever naming of the files will only get you so far.  Sometimes it’s the date the file was created that’s important, other times it’s the file format, and other times it’s the purpose of the file.  How do you name a collection of files so that they’re easy to isolate based on any of the above criteria?  Short answer, you can’t. Move files to a new computer.  It’s time to upgrade your computer.  How do you quickly grab all the files that are important to you?  Or you decide to have two computers now – one for home and one for work.  How do you quickly isolate only the work-related files to move them to the work computer? Synchronize files to other computers.  If you have more than one computer, and you need to mirror some of your files onto the other computer (e.g. your music collection), then you need a way to quickly determine which files are to be synced and which are not.  Surely you don’t want to synchronize everything? Choose which files to back up.  If your backup regime calls for multiple backups, or requires speedy backups, then you’ll need to be able to specify which files are to be backed up, and which are not.  This is not possible if they’re all in the same folder. Finally, if you’re simply someone who takes pleasure in being organized, tidy and ordered (me! me!), then you don’t even need a reason.  Being disorganized is simply unthinkable. Tips on Getting Organized Here we present our 40 best tips on how to get organized.  Or, if you’re already organized, to get better organized. Tip #1.  Choose Your Organization System Carefully The reason that most people are not organized is that it takes time.  And the first thing that takes time is deciding upon a system of organization.  This is always a matter of personal preference, and is not something that a geek on a website can tell you.  You should always choose your own system, based on how your own brain is organized (which makes the assumption that your brain is, in fact, organized). We can’t instruct you, but we can make suggestions: You may want to start off with a system based on the users of the computer.  i.e. “My Files”, “My Wife’s Files”, My Son’s Files”, etc.  Inside “My Files”, you might then break it down into “Personal” and “Business”.  You may then realize that there are overlaps.  For example, everyone may want to share access to the music library, or the photos from the school play.  So you may create another folder called “Family”, for the “common” files. You may decide that the highest-level breakdown of your files is based on the “source” of each file.  In other words, who created the files.  You could have “Files created by ME (business or personal)”, “Files created by people I know (family, friends, etc)”, and finally “Files created by the rest of the world (MP3 music files, downloaded or ripped movies or TV shows, software installation files, gorgeous desktop wallpaper images you’ve collected, etc).”  This system happens to be the one I use myself.  See below:  Mark is for files created by meVC is for files created by my company (Virtual Creations)Others is for files created by my friends and familyData is the rest of the worldAlso, Settings is where I store the configuration files and other program data files for my installed software (more on this in tip #34, below). Each folder will present its own particular set of requirements for further sub-organization.  For example, you may decide to organize your music collection into sub-folders based on the artist’s name, while your digital photos might get organized based on the date they were taken.  It can be different for every sub-folder! Another strategy would be based on “currentness”.  Files you have yet to open and look at live in one folder.  Ones that have been looked at but not yet filed live in another place.  Current, active projects live in yet another place.  All other files (your “archive”, if you like) would live in a fourth folder. (And of course, within that last folder you’d need to create a further sub-system based on one of the previous bullet points). Put some thought into this – changing it when it proves incomplete can be a big hassle!  Before you go to the trouble of implementing any system you come up with, examine a wide cross-section of the files you own and see if they will all be able to find a nice logical place to sit within your system. Tip #2.  When You Decide on Your System, Stick to It! There’s nothing more pointless than going to all the trouble of creating a system and filing all your files, and then whenever you create, receive or download a new file, you simply dump it onto your Desktop.  You need to be disciplined – forever!  Every new file you get, spend those extra few seconds to file it where it belongs!  Otherwise, in just a month or two, you’ll be worse off than before – half your files will be organized and half will be disorganized – and you won’t know which is which! Tip #3.  Choose the Root Folder of Your Structure Carefully Every data file (document, photo, music file, etc) that you create, own or is important to you, no matter where it came from, should be found within one single folder, and that one single folder should be located at the root of your C: drive (as a sub-folder of C:\).  In other words, do not base your folder structure in standard folders like “My Documents”.  If you do, then you’re leaving it up to the operating system engineers to decide what folder structure is best for you.  And every operating system has a different system!  In Windows 7 your files are found in C:\Users\YourName, whilst on Windows XP it was C:\Documents and Settings\YourName\My Documents.  In UNIX systems it’s often /home/YourName. These standard default folders tend to fill up with junk files and folders that are not at all important to you.  “My Documents” is the worst offender.  Every second piece of software you install, it seems, likes to create its own folder in the “My Documents” folder.  These folders usually don’t fit within your organizational structure, so don’t use them!  In fact, don’t even use the “My Documents” folder at all.  Allow it to fill up with junk, and then simply ignore it.  It sounds heretical, but: Don’t ever visit your “My Documents” folder!  Remove your icons/links to “My Documents” and replace them with links to the folders you created and you care about! Create your own file system from scratch!  Probably the best place to put it would be on your D: drive – if you have one.  This way, all your files live on one drive, while all the operating system and software component files live on the C: drive – simply and elegantly separated.  The benefits of that are profound.  Not only are there obvious organizational benefits (see tip #10, below), but when it comes to migrate your data to a new computer, you can (sometimes) simply unplug your D: drive and plug it in as the D: drive of your new computer (this implies that the D: drive is actually a separate physical disk, and not a partition on the same disk as C:).  You also get a slight speed improvement (again, only if your C: and D: drives are on separate physical disks). Warning:  From tip #12, below, you will see that it’s actually a good idea to have exactly the same file system structure – including the drive it’s filed on – on all of the computers you own.  So if you decide to use the D: drive as the storage system for your own files, make sure you are able to use the D: drive on all the computers you own.  If you can’t ensure that, then you can still use a clever geeky trick to store your files on the D: drive, but still access them all via the C: drive (see tip #17, below). If you only have one hard disk (C:), then create a dedicated folder that will contain all your files – something like C:\Files.  The name of the folder is not important, but make it a single, brief word. There are several reasons for this: When creating a backup regime, it’s easy to decide what files should be backed up – they’re all in the one folder! If you ever decide to trade in your computer for a new one, you know exactly which files to migrate You will always know where to begin a search for any file If you synchronize files with other computers, it makes your synchronization routines very simple.   It also causes all your shortcuts to continue to work on the other machines (more about this in tip #24, below). Once you’ve decided where your files should go, then put all your files in there – Everything!  Completely disregard the standard, default folders that are created for you by the operating system (“My Music”, “My Pictures”, etc).  In fact, you can actually relocate many of those folders into your own structure (more about that below, in tip #6). The more completely you get all your data files (documents, photos, music, etc) and all your configuration settings into that one folder, then the easier it will be to perform all of the above tasks. Once this has been done, and all your files live in one folder, all the other folders in C:\ can be thought of as “operating system” folders, and therefore of little day-to-day interest for us. Here’s a screenshot of a nicely organized C: drive, where all user files are located within the \Files folder:   Tip #4.  Use Sub-Folders This would be our simplest and most obvious tip.  It almost goes without saying.  Any organizational system you decide upon (see tip #1) will require that you create sub-folders for your files.  Get used to creating folders on a regular basis. Tip #5.  Don’t be Shy About Depth Create as many levels of sub-folders as you need.  Don’t be scared to do so.  Every time you notice an opportunity to group a set of related files into a sub-folder, do so.  Examples might include:  All the MP3s from one music CD, all the photos from one holiday, or all the documents from one client. It’s perfectly okay to put files into a folder called C:\Files\Me\From Others\Services\WestCo Bank\Statements\2009.  That’s only seven levels deep.  Ten levels is not uncommon.  Of course, it’s possible to take this too far.  If you notice yourself creating a sub-folder to hold only one file, then you’ve probably become a little over-zealous.  On the other hand, if you simply create a structure with only two levels (for example C:\Files\Work) then you really haven’t achieved any level of organization at all (unless you own only six files!).  Your “Work” folder will have become a dumping ground, just like your Desktop was, with most likely hundreds of files in it. Tip #6.  Move the Standard User Folders into Your Own Folder Structure Most operating systems, including Windows, create a set of standard folders for each of its users.  These folders then become the default location for files such as documents, music files, digital photos and downloaded Internet files.  In Windows 7, the full list is shown below: Some of these folders you may never use nor care about (for example, the Favorites folder, if you’re not using Internet Explorer as your browser).  Those ones you can leave where they are.  But you may be using some of the other folders to store files that are important to you.  Even if you’re not using them, Windows will still often treat them as the default storage location for many types of files.  When you go to save a standard file type, it can become annoying to be automatically prompted to save it in a folder that’s not part of your own file structure. But there’s a simple solution:  Move the folders you care about into your own folder structure!  If you do, then the next time you go to save a file of the corresponding type, Windows will prompt you to save it in the new, moved location. Moving the folders is easy.  Simply drag-and-drop them to the new location.  Here’s a screenshot of the default My Music folder being moved to my custom personal folder (Mark): Tip #7.  Name Files and Folders Intelligently This is another one that almost goes without saying, but we’ll say it anyway:  Do not allow files to be created that have meaningless names like Document1.doc, or folders called New Folder (2).  Take that extra 20 seconds and come up with a meaningful name for the file/folder – one that accurately divulges its contents without repeating the entire contents in the name. Tip #8.  Watch Out for Long Filenames Another way to tell if you have not yet created enough depth to your folder hierarchy is that your files often require really long names.  If you need to call a file Johnson Sales Figures March 2009.xls (which might happen to live in the same folder as Abercrombie Budget Report 2008.xls), then you might want to create some sub-folders so that the first file could be simply called March.xls, and living in the Clients\Johnson\Sales Figures\2009 folder. A well-placed file needs only a brief filename! Tip #9.  Use Shortcuts!  Everywhere! This is probably the single most useful and important tip we can offer.  A shortcut allows a file to be in two places at once. Why would you want that?  Well, the file and folder structure of every popular operating system on the market today is hierarchical.  This means that all objects (files and folders) always live within exactly one parent folder.  It’s a bit like a tree.  A tree has branches (folders) and leaves (files).  Each leaf, and each branch, is supported by exactly one parent branch, all the way back to the root of the tree (which, incidentally, is exactly why C:\ is called the “root folder” of the C: drive). That hard disks are structured this way may seem obvious and even necessary, but it’s only one way of organizing data.  There are others:  Relational databases, for example, organize structured data entirely differently.  The main limitation of hierarchical filing structures is that a file can only ever be in one branch of the tree – in only one folder – at a time.  Why is this a problem?  Well, there are two main reasons why this limitation is a problem for computer users: The “correct” place for a file, according to our organizational rationale, is very often a very inconvenient place for that file to be located.  Just because it’s correctly filed doesn’t mean it’s easy to get to.  Your file may be “correctly” buried six levels deep in your sub-folder structure, but you may need regular and speedy access to this file every day.  You could always move it to a more convenient location, but that would mean that you would need to re-file back to its “correct” location it every time you’d finished working on it.  Most unsatisfactory. A file may simply “belong” in two or more different locations within your file structure.  For example, say you’re an accountant and you have just completed the 2009 tax return for John Smith.  It might make sense to you to call this file 2009 Tax Return.doc and file it under Clients\John Smith.  But it may also be important to you to have the 2009 tax returns from all your clients together in the one place.  So you might also want to call the file John Smith.doc and file it under Tax Returns\2009.  The problem is, in a purely hierarchical filing system, you can’t put it in both places.  Grrrrr! Fortunately, Windows (and most other operating systems) offers a way for you to do exactly that:  It’s called a “shortcut” (also known as an “alias” on Macs and a “symbolic link” on UNIX systems).  Shortcuts allow a file to exist in one place, and an icon that represents the file to be created and put anywhere else you please.  In fact, you can create a dozen such icons and scatter them all over your hard disk.  Double-clicking on one of these icons/shortcuts opens up the original file, just as if you had double-clicked on the original file itself. Consider the following two icons: The one on the left is the actual Word document, while the one on the right is a shortcut that represents the Word document.  Double-clicking on either icon will open the same file.  There are two main visual differences between the icons: The shortcut will have a small arrow in the lower-left-hand corner (on Windows, anyway) The shortcut is allowed to have a name that does not include the file extension (the “.docx” part, in this case) You can delete the shortcut at any time without losing any actual data.  The original is still intact.  All you lose is the ability to get to that data from wherever the shortcut was. So why are shortcuts so great?  Because they allow us to easily overcome the main limitation of hierarchical file systems, and put a file in two (or more) places at the same time.  You will always have files that don’t play nice with your organizational rationale, and can’t be filed in only one place.  They demand to exist in two places.  Shortcuts allow this!  Furthermore, they allow you to collect your most often-opened files and folders together in one spot for convenient access.  The cool part is that the original files stay where they are, safe forever in their perfectly organized location. So your collection of most often-opened files can – and should – become a collection of shortcuts! If you’re still not convinced of the utility of shortcuts, consider the following well-known areas of a typical Windows computer: The Start Menu (and all the programs that live within it) The Quick Launch bar (or the Superbar in Windows 7) The “Favorite folders” area in the top-left corner of the Windows Explorer window (in Windows Vista or Windows 7) Your Internet Explorer Favorites or Firefox Bookmarks Each item in each of these areas is a shortcut!  Each of those areas exist for one purpose only:  For convenience – to provide you with a collection of the files and folders you access most often. It should be easy to see by now that shortcuts are designed for one single purpose:  To make accessing your files more convenient.  Each time you double-click on a shortcut, you are saved the hassle of locating the file (or folder, or program, or drive, or control panel icon) that it represents. Shortcuts allow us to invent a golden rule of file and folder organization: “Only ever have one copy of a file – never have two copies of the same file.  Use a shortcut instead” (this rule doesn’t apply to copies created for backup purposes, of course!) There are also lesser rules, like “don’t move a file into your work area – create a shortcut there instead”, and “any time you find yourself frustrated with how long it takes to locate a file, create a shortcut to it and place that shortcut in a convenient location.” So how to we create these massively useful shortcuts?  There are two main ways: “Copy” the original file or folder (click on it and type Ctrl-C, or right-click on it and select Copy):  Then right-click in an empty area of the destination folder (the place where you want the shortcut to go) and select Paste shortcut: Right-drag (drag with the right mouse button) the file from the source folder to the destination folder.  When you let go of the mouse button at the destination folder, a menu pops up: Select Create shortcuts here. Note that when shortcuts are created, they are often named something like Shortcut to Budget Detail.doc (windows XP) or Budget Detail – Shortcut.doc (Windows 7).   If you don’t like those extra words, you can easily rename the shortcuts after they’re created, or you can configure Windows to never insert the extra words in the first place (see our article on how to do this). And of course, you can create shortcuts to folders too, not just to files! Bottom line: Whenever you have a file that you’d like to access from somewhere else (whether it’s convenience you’re after, or because the file simply belongs in two places), create a shortcut to the original file in the new location. Tip #10.  Separate Application Files from Data Files Any digital organization guru will drum this rule into you.  Application files are the components of the software you’ve installed (e.g. Microsoft Word, Adobe Photoshop or Internet Explorer).  Data files are the files that you’ve created for yourself using that software (e.g. Word Documents, digital photos, emails or playlists). Software gets installed, uninstalled and upgraded all the time.  Hopefully you always have the original installation media (or downloaded set-up file) kept somewhere safe, and can thus reinstall your software at any time.  This means that the software component files are of little importance.  Whereas the files you have created with that software is, by definition, important.  It’s a good rule to always separate unimportant files from important files. So when your software prompts you to save a file you’ve just created, take a moment and check out where it’s suggesting that you save the file.  If it’s suggesting that you save the file into the same folder as the software itself, then definitely don’t follow that suggestion.  File it in your own folder!  In fact, see if you can find the program’s configuration option that determines where files are saved by default (if it has one), and change it. Tip #11.  Organize Files Based on Purpose, Not on File Type If you have, for example a folder called Work\Clients\Johnson, and within that folder you have two sub-folders, Word Documents and Spreadsheets (in other words, you’re separating “.doc” files from “.xls” files), then chances are that you’re not optimally organized.  It makes little sense to organize your files based on the program that created them.  Instead, create your sub-folders based on the purpose of the file.  For example, it would make more sense to create sub-folders called Correspondence and Financials.  It may well be that all the files in a given sub-folder are of the same file-type, but this should be more of a coincidence and less of a design feature of your organization system. Tip #12.  Maintain the Same Folder Structure on All Your Computers In other words, whatever organizational system you create, apply it to every computer that you can.  There are several benefits to this: There’s less to remember.  No matter where you are, you always know where to look for your files If you copy or synchronize files from one computer to another, then setting up the synchronization job becomes very simple Shortcuts can be copied or moved from one computer to another with ease (assuming the original files are also copied/moved).  There’s no need to find the target of the shortcut all over again on the second computer Ditto for linked files (e.g Word documents that link to data in a separate Excel file), playlists, and any files that reference the exact file locations of other files. This applies even to the drive that your files are stored on.  If your files are stored on C: on one computer, make sure they’re stored on C: on all your computers.  Otherwise all your shortcuts, playlists and linked files will stop working! Tip #13.  Create an “Inbox” Folder Create yourself a folder where you store all files that you’re currently working on, or that you haven’t gotten around to filing yet.  You can think of this folder as your “to-do” list.  You can call it “Inbox” (making it the same metaphor as your email system), or “Work”, or “To-Do”, or “Scratch”, or whatever name makes sense to you.  It doesn’t matter what you call it – just make sure you have one! Once you have finished working on a file, you then move it from the “Inbox” to its correct location within your organizational structure. You may want to use your Desktop as this “Inbox” folder.  Rightly or wrongly, most people do.  It’s not a bad place to put such files, but be careful:  If you do decide that your Desktop represents your “to-do” list, then make sure that no other files find their way there.  In other words, make sure that your “Inbox”, wherever it is, Desktop or otherwise, is kept free of junk – stray files that don’t belong there. So where should you put this folder, which, almost by definition, lives outside the structure of the rest of your filing system?  Well, first and foremost, it has to be somewhere handy.  This will be one of your most-visited folders, so convenience is key.  Putting it on the Desktop is a great option – especially if you don’t have any other folders on your Desktop:  the folder then becomes supremely easy to find in Windows Explorer: You would then create shortcuts to this folder in convenient spots all over your computer (“Favorite Links”, “Quick Launch”, etc). Tip #14.  Ensure You have Only One “Inbox” Folder Once you’ve created your “Inbox” folder, don’t use any other folder location as your “to-do list”.  Throw every incoming or created file into the Inbox folder as you create/receive it.  This keeps the rest of your computer pristine and free of randomly created or downloaded junk.  The last thing you want to be doing is checking multiple folders to see all your current tasks and projects.  Gather them all together into one folder. Here are some tips to help ensure you only have one Inbox: Set the default “save” location of all your programs to this folder. Set the default “download” location for your browser to this folder. If this folder is not your desktop (recommended) then also see if you can make a point of not putting “to-do” files on your desktop.  This keeps your desktop uncluttered and Zen-like: (the Inbox folder is in the bottom-right corner) Tip #15.  Be Vigilant about Clearing Your “Inbox” Folder This is one of the keys to staying organized.  If you let your “Inbox” overflow (i.e. allow there to be more than, say, 30 files or folders in there), then you’re probably going to start feeling like you’re overwhelmed:  You’re not keeping up with your to-do list.  Once your Inbox gets beyond a certain point (around 30 files, studies have shown), then you’ll simply start to avoid it.  You may continue to put files in there, but you’ll be scared to look at it, fearing the “out of control” feeling that all overworked, chaotic or just plain disorganized people regularly feel. So, here’s what you can do: Visit your Inbox/to-do folder regularly (at least five times per day). Scan the folder regularly for files that you have completed working on and are ready for filing.  File them immediately. Make it a source of pride to keep the number of files in this folder as small as possible.  If you value peace of mind, then make the emptiness of this folder one of your highest (computer) priorities If you know that a particular file has been in the folder for more than, say, six weeks, then admit that you’re not actually going to get around to processing it, and move it to its final resting place. Tip #16.  File Everything Immediately, and Use Shortcuts for Your Active Projects As soon as you create, receive or download a new file, store it away in its “correct” folder immediately.  Then, whenever you need to work on it (possibly straight away), create a shortcut to it in your “Inbox” (“to-do”) folder or your desktop.  That way, all your files are always in their “correct” locations, yet you still have immediate, convenient access to your current, active files.  When you finish working on a file, simply delete the shortcut. Ideally, your “Inbox” folder – and your Desktop – should contain no actual files or folders.  They should simply contain shortcuts. Tip #17.  Use Directory Symbolic Links (or Junctions) to Maintain One Unified Folder Structure Using this tip, we can get around a potential hiccup that we can run into when creating our organizational structure – the issue of having more than one drive on our computer (C:, D:, etc).  We might have files we need to store on the D: drive for space reasons, and yet want to base our organized folder structure on the C: drive (or vice-versa). Your chosen organizational structure may dictate that all your files must be accessed from the C: drive (for example, the root folder of all your files may be something like C:\Files).  And yet you may still have a D: drive and wish to take advantage of the hundreds of spare Gigabytes that it offers.  Did you know that it’s actually possible to store your files on the D: drive and yet access them as if they were on the C: drive?  And no, we’re not talking about shortcuts here (although the concept is very similar). By using the shell command mklink, you can essentially take a folder that lives on one drive and create an alias for it on a different drive (you can do lots more than that with mklink – for a full rundown on this programs capabilities, see our dedicated article).  These aliases are called directory symbolic links (and used to be known as junctions).  You can think of them as “virtual” folders.  They function exactly like regular folders, except they’re physically located somewhere else. For example, you may decide that your entire D: drive contains your complete organizational file structure, but that you need to reference all those files as if they were on the C: drive, under C:\Files.  If that was the case you could create C:\Files as a directory symbolic link – a link to D:, as follows: mklink /d c:\files d:\ Or it may be that the only files you wish to store on the D: drive are your movie collection.  You could locate all your movie files in the root of your D: drive, and then link it to C:\Files\Media\Movies, as follows: mklink /d c:\files\media\movies d:\ (Needless to say, you must run these commands from a command prompt – click the Start button, type cmd and press Enter) Tip #18. Customize Your Folder Icons This is not strictly speaking an organizational tip, but having unique icons for each folder does allow you to more quickly visually identify which folder is which, and thus saves you time when you’re finding files.  An example is below (from my folder that contains all files downloaded from the Internet): To learn how to change your folder icons, please refer to our dedicated article on the subject. Tip #19.  Tidy Your Start Menu The Windows Start Menu is usually one of the messiest parts of any Windows computer.  Every program you install seems to adopt a completely different approach to placing icons in this menu.  Some simply put a single program icon.  Others create a folder based on the name of the software.  And others create a folder based on the name of the software manufacturer.  It’s chaos, and can make it hard to find the software you want to run. Thankfully we can avoid this chaos with useful operating system features like Quick Launch, the Superbar or pinned start menu items. Even so, it would make a lot of sense to get into the guts of the Start Menu itself and give it a good once-over.  All you really need to decide is how you’re going to organize your applications.  A structure based on the purpose of the application is an obvious candidate.  Below is an example of one such structure: In this structure, Utilities means software whose job it is to keep the computer itself running smoothly (configuration tools, backup software, Zip programs, etc).  Applications refers to any productivity software that doesn’t fit under the headings Multimedia, Graphics, Internet, etc. In case you’re not aware, every icon in your Start Menu is a shortcut and can be manipulated like any other shortcut (copied, moved, deleted, etc). With the Windows Start Menu (all version of Windows), Microsoft has decided that there be two parallel folder structures to store your Start Menu shortcuts.  One for you (the logged-in user of the computer) and one for all users of the computer.  Having two parallel structures can often be redundant:  If you are the only user of the computer, then having two parallel structures is totally redundant.  Even if you have several users that regularly log into the computer, most of your installed software will need to be made available to all users, and should thus be moved out of the “just you” version of the Start Menu and into the “all users” area. To take control of your Start Menu, so you can start organizing it, you’ll need to know how to access the actual folders and shortcut files that make up the Start Menu (both versions of it).  To find these folders and files, click the Start button and then right-click on the All Programs text (Windows XP users should right-click on the Start button itself): The Open option refers to the “just you” version of the Start Menu, while the Open All Users option refers to the “all users” version.  Click on the one you want to organize. A Windows Explorer window then opens with your chosen version of the Start Menu selected.  From there it’s easy.  Double-click on the Programs folder and you’ll see all your folders and shortcuts.  Now you can delete/rename/move until it’s just the way you want it. Note:  When you’re reorganizing your Start Menu, you may want to have two Explorer windows open at the same time – one showing the “just you” version and one showing the “all users” version.  You can drag-and-drop between the windows. Tip #20.  Keep Your Start Menu Tidy Once you have a perfectly organized Start Menu, try to be a little vigilant about keeping it that way.  Every time you install a new piece of software, the icons that get created will almost certainly violate your organizational structure. So to keep your Start Menu pristine and organized, make sure you do the following whenever you install a new piece of software: Check whether the software was installed into the “just you” area of the Start Menu, or the “all users” area, and then move it to the correct area. Remove all the unnecessary icons (like the “Read me” icon, the “Help” icon (you can always open the help from within the software itself when it’s running), the “Uninstall” icon, the link(s)to the manufacturer’s website, etc) Rename the main icon(s) of the software to something brief that makes sense to you.  For example, you might like to rename Microsoft Office Word 2010 to simply Word Move the icon(s) into the correct folder based on your Start Menu organizational structure And don’t forget:  when you uninstall a piece of software, the software’s uninstall routine is no longer going to be able to remove the software’s icon from the Start Menu (because you moved and/or renamed it), so you’ll need to remove that icon manually. Tip #21.  Tidy C:\ The root of your C: drive (C:\) is a common dumping ground for files and folders – both by the users of your computer and by the software that you install on your computer.  It can become a mess. There’s almost no software these days that requires itself to be installed in C:\.  99% of the time it can and should be installed into C:\Program Files.  And as for your own files, well, it’s clear that they can (and almost always should) be stored somewhere else. In an ideal world, your C:\ folder should look like this (on Windows 7): Note that there are some system files and folders in C:\ that are usually and deliberately “hidden” (such as the Windows virtual memory file pagefile.sys, the boot loader file bootmgr, and the System Volume Information folder).  Hiding these files and folders is a good idea, as they need to stay where they are and are almost never needed to be opened or even seen by you, the user.  Hiding them prevents you from accidentally messing with them, and enhances your sense of order and well-being when you look at your C: drive folder. Tip #22.  Tidy Your Desktop The Desktop is probably the most abused part of a Windows computer (from an organization point of view).  It usually serves as a dumping ground for all incoming files, as well as holding icons to oft-used applications, plus some regularly opened files and folders.  It often ends up becoming an uncontrolled mess.  See if you can avoid this.  Here’s why… Application icons (Word, Internet Explorer, etc) are often found on the Desktop, but it’s unlikely that this is the optimum place for them.  The “Quick Launch” bar (or the Superbar in Windows 7) is always visible and so represents a perfect location to put your icons.  You’ll only be able to see the icons on your Desktop when all your programs are minimized.  It might be time to get your application icons off your desktop… You may have decided that the Inbox/To-do folder on your computer (see tip #13, above) should be your Desktop.  If so, then enough said.  Simply be vigilant about clearing it and preventing it from being polluted by junk files (see tip #15, above).  On the other hand, if your Desktop is not acting as your “Inbox” folder, then there’s no reason for it to have any data files or folders on it at all, except perhaps a couple of shortcuts to often-opened files and folders (either ongoing or current projects).  Everything else should be moved to your “Inbox” folder. In an ideal world, it might look like this: Tip #23.  Move Permanent Items on Your Desktop Away from the Top-Left Corner When files/folders are dragged onto your desktop in a Windows Explorer window, or when shortcuts are created on your Desktop from Internet Explorer, those icons are always placed in the top-left corner – or as close as they can get.  If you have other files, folders or shortcuts that you keep on the Desktop permanently, then it’s a good idea to separate these permanent icons from the transient ones, so that you can quickly identify which ones the transients are.  An easy way to do this is to move all your permanent icons to the right-hand side of your Desktop.  That should keep them separated from incoming items. Tip #24.  Synchronize If you have more than one computer, you’ll almost certainly want to share files between them.  If the computers are permanently attached to the same local network, then there’s no need to store multiple copies of any one file or folder – shortcuts will suffice.  However, if the computers are not always on the same network, then you will at some point need to copy files between them.  For files that need to permanently live on both computers, the ideal way to do this is to synchronize the files, as opposed to simply copying them. We only have room here to write a brief summary of synchronization, not a full article.  In short, there are several different types of synchronization: Where the contents of one folder are accessible anywhere, such as with Dropbox Where the contents of any number of folders are accessible anywhere, such as with Windows Live Mesh Where any files or folders from anywhere on your computer are synchronized with exactly one other computer, such as with the Windows “Briefcase”, Microsoft SyncToy, or (much more powerful, yet still free) SyncBack from 2BrightSparks.  This only works when both computers are on the same local network, at least temporarily. A great advantage of synchronization solutions is that once you’ve got it configured the way you want it, then the sync process happens automatically, every time.  Click a button (or schedule it to happen automatically) and all your files are automagically put where they’re supposed to be. If you maintain the same file and folder structure on both computers, then you can also sync files depend upon the correct location of other files, like shortcuts, playlists and office documents that link to other office documents, and the synchronized files still work on the other computer! Tip #25.  Hide Files You Never Need to See If you have your files well organized, you will often be able to tell if a file is out of place just by glancing at the contents of a folder (for example, it should be pretty obvious if you look in a folder that contains all the MP3s from one music CD and see a Word document in there).  This is a good thing – it allows you to determine if there are files out of place with a quick glance.  Yet sometimes there are files in a folder that seem out of place but actually need to be there, such as the “folder art” JPEGs in music folders, and various files in the root of the C: drive.  If such files never need to be opened by you, then a good idea is to simply hide them.  Then, the next time you glance at the folder, you won’t have to remember whether that file was supposed to be there or not, because you won’t see it at all! To hide a file, simply right-click on it and choose Properties: Then simply tick the Hidden tick-box:   Tip #26.  Keep Every Setup File These days most software is downloaded from the Internet.  Whenever you download a piece of software, keep it.  You’ll never know when you need to reinstall the software. Further, keep with it an Internet shortcut that links back to the website where you originally downloaded it, in case you ever need to check for updates. See tip #33 below for a full description of the excellence of organizing your setup files. Tip #27.  Try to Minimize the Number of Folders that Contain Both Files and Sub-folders Some of the folders in your organizational structure will contain only files.  Others will contain only sub-folders.  And you will also have some folders that contain both files and sub-folders.  You will notice slight improvements in how long it takes you to locate a file if you try to avoid this third type of folder.  It’s not always possible, of course – you’ll always have some of these folders, but see if you can avoid it. One way of doing this is to take all the leftover files that didn’t end up getting stored in a sub-folder and create a special “Miscellaneous” or “Other” folder for them. Tip #28.  Starting a Filename with an Underscore Brings it to the Top of a List Further to the previous tip, if you name that “Miscellaneous” or “Other” folder in such a way that its name begins with an underscore “_”, then it will appear at the top of the list of files/folders. The screenshot below is an example of this.  Each folder in the list contains a set of digital photos.  The folder at the top of the list, _Misc, contains random photos that didn’t deserve their own dedicated folder: Tip #29.  Clean Up those CD-ROMs and (shudder!) Floppy Disks Have you got a pile of CD-ROMs stacked on a shelf of your office?  Old photos, or files you archived off onto CD-ROM (or even worse, floppy disks!) because you didn’t have enough disk space at the time?  In the meantime have you upgraded your computer and now have 500 Gigabytes of space you don’t know what to do with?  If so, isn’t it time you tidied up that stack of disks and filed them into your gorgeous new folder structure? So what are you waiting for?  Bite the bullet, copy them all back onto your computer, file them in their appropriate folders, and then back the whole lot up onto a shiny new 1000Gig external hard drive! Useful Folders to Create This next section suggests some useful folders that you might want to create within your folder structure.  I’ve personally found them to be indispensable. The first three are all about convenience – handy folders to create and then put somewhere that you can always access instantly.  For each one, it’s not so important where the actual folder is located, but it’s very important where you put the shortcut(s) to the folder.  You might want to locate the shortcuts: On your Desktop In your “Quick Launch” area (or pinned to your Windows 7 Superbar) In your Windows Explorer “Favorite Links” area Tip #30.  Create an “Inbox” (“To-Do”) Folder This has already been mentioned in depth (see tip #13), but we wanted to reiterate its importance here.  This folder contains all the recently created, received or downloaded files that you have not yet had a chance to file away properly, and it also may contain files that you have yet to process.  In effect, it becomes a sort of “to-do list”.  It doesn’t have to be called “Inbox” – you can call it whatever you want. Tip #31.  Create a Folder where Your Current Projects are Collected Rather than going hunting for them all the time, or dumping them all on your desktop, create a special folder where you put links (or work folders) for each of the projects you’re currently working on. You can locate this folder in your “Inbox” folder, on your desktop, or anywhere at all – just so long as there’s a way of getting to it quickly, such as putting a link to it in Windows Explorer’s “Favorite Links” area: Tip #32.  Create a Folder for Files and Folders that You Regularly Open You will always have a few files that you open regularly, whether it be a spreadsheet of your current accounts, or a favorite playlist.  These are not necessarily “current projects”, rather they’re simply files that you always find yourself opening.  Typically such files would be located on your desktop (or even better, shortcuts to those files).  Why not collect all such shortcuts together and put them in their own special folder? As with the “Current Projects” folder (above), you would want to locate that folder somewhere convenient.  Below is an example of a folder called “Quick links”, with about seven files (shortcuts) in it, that is accessible through the Windows Quick Launch bar: See tip #37 below for a full explanation of the power of the Quick Launch bar. Tip #33.  Create a “Set-ups” Folder A typical computer has dozens of applications installed on it.  For each piece of software, there are often many different pieces of information you need to keep track of, including: The original installation setup file(s).  This can be anything from a simple 100Kb setup.exe file you downloaded from a website, all the way up to a 4Gig ISO file that you copied from a DVD-ROM that you purchased. The home page of the software manufacturer (in case you need to look up something on their support pages, their forum or their online help) The page containing the download link for your actual file (in case you need to re-download it, or download an upgraded version) The serial number Your proof-of-purchase documentation Any other template files, plug-ins, themes, etc that also need to get installed For each piece of software, it’s a great idea to gather all of these files together and put them in a single folder.  The folder can be the name of the software (plus possibly a very brief description of what it’s for – in case you can’t remember what the software does based in its name).  Then you would gather all of these folders together into one place, and call it something like “Software” or “Setups”. If you have enough of these folders (I have several hundred, being a geek, collected over 20 years), then you may want to further categorize them.  My own categorization structure is based on “platform” (operating system): The last seven folders each represents one platform/operating system, while _Operating Systems contains set-up files for installing the operating systems themselves.  _Hardware contains ROMs for hardware I own, such as routers. Within the Windows folder (above), you can see the beginnings of the vast library of software I’ve compiled over the years: An example of a typical application folder looks like this: Tip #34.  Have a “Settings” Folder We all know that our documents are important.  So are our photos and music files.  We save all of these files into folders, and then locate them afterwards and double-click on them to open them.  But there are many files that are important to us that can’t be saved into folders, and then searched for and double-clicked later on.  These files certainly contain important information that we need, but are often created internally by an application, and saved wherever that application feels is appropriate. A good example of this is the “PST” file that Outlook creates for us and uses to store all our emails, contacts, appointments and so forth.  Another example would be the collection of Bookmarks that Firefox stores on your behalf. And yet another example would be the customized settings and configuration files of our all our software.  Granted, most Windows programs store their configuration in the Registry, but there are still many programs that use configuration files to store their settings. Imagine if you lost all of the above files!  And yet, when people are backing up their computers, they typically only back up the files they know about – those that are stored in the “My Documents” folder, etc.  If they had a hard disk failure or their computer was lost or stolen, their backup files would not include some of the most vital files they owned.  Also, when migrating to a new computer, it’s vital to ensure that these files make the journey. It can be a very useful idea to create yourself a folder to store all your “settings” – files that are important to you but which you never actually search for by name and double-click on to open them.  Otherwise, next time you go to set up a new computer just the way you want it, you’ll need to spend hours recreating the configuration of your previous computer! So how to we get our important files into this folder?  Well, we have a few options: Some programs (such as Outlook and its PST files) allow you to place these files wherever you want.  If you delve into the program’s options, you will find a setting somewhere that controls the location of the important settings files (or “personal storage” – PST – when it comes to Outlook) Some programs do not allow you to change such locations in any easy way, but if you get into the Registry, you can sometimes find a registry key that refers to the location of the file(s).  Simply move the file into your Settings folder and adjust the registry key to refer to the new location. Some programs stubbornly refuse to allow their settings files to be placed anywhere other then where they stipulate.  When faced with programs like these, you have three choices:  (1) You can ignore those files, (2) You can copy the files into your Settings folder (let’s face it – settings don’t change very often), or (3) you can use synchronization software, such as the Windows Briefcase, to make synchronized copies of all your files in your Settings folder.  All you then have to do is to remember to run your sync software periodically (perhaps just before you run your backup software!). There are some other things you may decide to locate inside this new “Settings” folder: Exports of registry keys (from the many applications that store their configurations in the Registry).  This is useful for backup purposes or for migrating to a new computer Notes you’ve made about all the specific customizations you have made to a particular piece of software (so that you’ll know how to do it all again on your next computer) Shortcuts to webpages that detail how to tweak certain aspects of your operating system or applications so they are just the way you like them (such as how to remove the words “Shortcut to” from the beginning of newly created shortcuts).  In other words, you’d want to create shortcuts to half the pages on the How-To Geek website! Here’s an example of a “Settings” folder: Windows Features that Help with Organization This section details some of the features of Microsoft Windows that are a boon to anyone hoping to stay optimally organized. Tip #35.  Use the “Favorite Links” Area to Access Oft-Used Folders Once you’ve created your great new filing system, work out which folders you access most regularly, or which serve as great starting points for locating the rest of the files in your folder structure, and then put links to those folders in your “Favorite Links” area of the left-hand side of the Windows Explorer window (simply called “Favorites” in Windows 7):   Some ideas for folders you might want to add there include: Your “Inbox” folder (or whatever you’ve called it) – most important! The base of your filing structure (e.g. C:\Files) A folder containing shortcuts to often-accessed folders on other computers around the network (shown above as Network Folders) A folder containing shortcuts to your current projects (unless that folder is in your “Inbox” folder) Getting folders into this area is very simple – just locate the folder you’re interested in and drag it there! Tip #36.  Customize the Places Bar in the File/Open and File/Save Boxes Consider the screenshot below: The highlighted icons (collectively known as the “Places Bar”) can be customized to refer to any folder location you want, allowing instant access to any part of your organizational structure. Note:  These File/Open and File/Save boxes have been superseded by new versions that use the Windows Vista/Windows 7 “Favorite Links”, but the older versions (shown above) are still used by a surprisingly large number of applications. The easiest way to customize these icons is to use the Group Policy Editor, but not everyone has access to this program.  If you do, open it up and navigate to: User Configuration > Administrative Templates > Windows Components > Windows Explorer > Common Open File Dialog If you don’t have access to the Group Policy Editor, then you’ll need to get into the Registry.  Navigate to: HKEY_CURRENT_USER \ Software \ Microsoft  \ Windows \ CurrentVersion \ Policies \ comdlg32 \ Placesbar It should then be easy to make the desired changes.  Log off and log on again to allow the changes to take effect. Tip #37.  Use the Quick Launch Bar as a Application and File Launcher That Quick Launch bar (to the right of the Start button) is a lot more useful than people give it credit for.  Most people simply have half a dozen icons in it, and use it to start just those programs.  But it can actually be used to instantly access just about anything in your filing system: For complete instructions on how to set this up, visit our dedicated article on this topic. Tip #38.  Put a Shortcut to Windows Explorer into Your Quick Launch Bar This is only necessary in Windows Vista and Windows XP.  The Microsoft boffins finally got wise and added it to the Windows 7 Superbar by default. Windows Explorer – the program used for managing your files and folders – is one of the most useful programs in Windows.  Anyone who considers themselves serious about being organized needs instant access to this program at any time.  A great place to create a shortcut to this program is in the Windows XP and Windows Vista “Quick Launch” bar: To get it there, locate it in your Start Menu (usually under “Accessories”) and then right-drag it down into your Quick Launch bar (and create a copy). Tip #39.  Customize the Starting Folder for Your Windows 7 Explorer Superbar Icon If you’re on Windows 7, your Superbar will include a Windows Explorer icon.  Clicking on the icon will launch Windows Explorer (of course), and will start you off in your “Libraries” folder.  Libraries may be fine as a starting point, but if you have created yourself an “Inbox” folder, then it would probably make more sense to start off in this folder every time you launch Windows Explorer. To change this default/starting folder location, then first right-click the Explorer icon in the Superbar, and then right-click Properties:Then, in Target field of the Windows Explorer Properties box that appears, type %windir%\explorer.exe followed by the path of the folder you wish to start in.  For example: %windir%\explorer.exe C:\Files If that folder happened to be on the Desktop (and called, say, “Inbox”), then you would use the following cleverness: %windir%\explorer.exe shell:desktop\Inbox Then click OK and test it out. Tip #40.  Ummmmm…. No, that’s it.  I can’t think of another one.  That’s all of the tips I can come up with.  I only created this one because 40 is such a nice round number… Case Study – An Organized PC To finish off the article, I have included a few screenshots of my (main) computer (running Vista).  The aim here is twofold: To give you a sense of what it looks like when the above, sometimes abstract, tips are applied to a real-life computer, and To offer some ideas about folders and structure that you may want to steal to use on your own PC. Let’s start with the C: drive itself.  Very minimal.  All my files are contained within C:\Files.  I’ll confine the rest of the case study to this folder: That folder contains the following: Mark: My personal files VC: My business (Virtual Creations, Australia) Others contains files created by friends and family Data contains files from the rest of the world (can be thought of as “public” files, usually downloaded from the Net) Settings is described above in tip #34 The Data folder contains the following sub-folders: Audio:  Radio plays, audio books, podcasts, etc Development:  Programmer and developer resources, sample source code, etc (see below) Humour:  Jokes, funnies (those emails that we all receive) Movies:  Downloaded and ripped movies (all legal, of course!), their scripts, DVD covers, etc. Music:  (see below) Setups:  Installation files for software (explained in full in tip #33) System:  (see below) TV:  Downloaded TV shows Writings:  Books, instruction manuals, etc (see below) The Music folder contains the following sub-folders: Album covers:  JPEG scans Guitar tabs:  Text files of guitar sheet music Lists:  e.g. “Top 1000 songs of all time” Lyrics:  Text files MIDI:  Electronic music files MP3 (representing 99% of the Music folder):  MP3s, either ripped from CDs or downloaded, sorted by artist/album name Music Video:  Video clips Sheet Music:  usually PDFs The Data\Writings folder contains the following sub-folders: (all pretty self-explanatory) The Data\Development folder contains the following sub-folders: Again, all pretty self-explanatory (if you’re a geek) The Data\System folder contains the following sub-folders: These are usually themes, plug-ins and other downloadable program-specific resources. The Mark folder contains the following sub-folders: From Others:  Usually letters that other people (friends, family, etc) have written to me For Others:  Letters and other things I have created for other people Green Book:  None of your business Playlists:  M3U files that I have compiled of my favorite songs (plus one M3U playlist file for every album I own) Writing:  Fiction, philosophy and other musings of mine Mark Docs:  Shortcut to C:\Users\Mark Settings:  Shortcut to C:\Files\Settings\Mark The Others folder contains the following sub-folders: The VC (Virtual Creations, my business – I develop websites) folder contains the following sub-folders: And again, all of those are pretty self-explanatory. Conclusion These tips have saved my sanity and helped keep me a productive geek, but what about you? What tips and tricks do you have to keep your files organized?  Please share them with us in the comments.  Come on, don’t be shy… Similar Articles Productive Geek Tips Fix For When Windows Explorer in Vista Stops Showing File NamesWhy Did Windows Vista’s Music Folder Icon Turn Yellow?Print or Create a Text File List of the Contents in a Directory the Easy WayCustomize the Windows 7 or Vista Send To MenuAdd Copy To / Move To on Windows 7 or Vista Right-Click Menu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Acronis Online Backup DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows Track Daily Goals With 42Goals Video Toolbox is a Superb Online Video Editor Fun with 47 charts and graphs Tomorrow is Mother’s Day Check the Average Speed of YouTube Videos You’ve Watched OutlookStatView Scans and Displays General Usage Statistics

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• problem with google chrome

  - by user365559

  hi. i have javscript file for history management.IT is not supported by chrome when i am trying to navigate to back page with backbutton in the browser.I can see the url change but it doesnt go to preceeding page. BrowserHistoryUtils = { addEvent: function(elm, evType, fn, useCapture) { useCapture = useCapture || false; if (elm.addEventListener) { elm.addEventListener(evType, fn, useCapture); return true; } else if (elm.attachEvent) { var r = elm.attachEvent('on' + evType, fn); return r; } else { elm['on' + evType] = fn; } } } BrowserHistory = (function() { // type of browser var browser = { ie: false, firefox: false, safari: false, opera: false, version: -1 }; // if setDefaultURL has been called, our first clue // that the SWF is ready and listening //var swfReady = false; // the URL we'll send to the SWF once it is ready //var pendingURL = ''; // Default app state URL to use when no fragment ID present var defaultHash = ''; // Last-known app state URL var currentHref = document.location.href; // Initial URL (used only by IE) var initialHref = document.location.href; // Initial URL (used only by IE) var initialHash = document.location.hash; // History frame source URL prefix (used only by IE) var historyFrameSourcePrefix = 'history/historyFrame.html?'; // History maintenance (used only by Safari) var currentHistoryLength = -1; var historyHash = []; var initialState = createState(initialHref, initialHref + '#' + initialHash, initialHash); var backStack = []; var forwardStack = []; var currentObjectId = null; //UserAgent detection var useragent = navigator.userAgent.toLowerCase(); if (useragent.indexOf("opera") != -1) { browser.opera = true; } else if (useragent.indexOf("msie") != -1) { browser.ie = true; browser.version = parseFloat(useragent.substring(useragent.indexOf('msie') + 4)); } else if (useragent.indexOf("safari") != -1) { browser.safari = true; browser.version = parseFloat(useragent.substring(useragent.indexOf('safari') + 7)); } else if (useragent.indexOf("gecko") != -1) { browser.firefox = true; } if (browser.ie == true && browser.version == 7) { window["_ie_firstload"] = false; } // Accessor functions for obtaining specific elements of the page. function getHistoryFrame() { return document.getElementById('ie_historyFrame'); } function getAnchorElement() { return document.getElementById('firefox_anchorDiv'); } function getFormElement() { return document.getElementById('safari_formDiv'); } function getRememberElement() { return document.getElementById("safari_remember_field"); } // Get the Flash player object for performing ExternalInterface callbacks. // Updated for changes to SWFObject2. function getPlayer(id) { if (id && document.getElementById(id)) { var r = document.getElementById(id); if (typeof r.SetVariable != "undefined") { return r; } else { var o = r.getElementsByTagName("object"); var e = r.getElementsByTagName("embed"); if (o.length > 0 && typeof o[0].SetVariable != "undefined") { return o[0]; } else if (e.length > 0 && typeof e[0].SetVariable != "undefined") { return e[0]; } } } else { var o = document.getElementsByTagName("object"); var e = document.getElementsByTagName("embed"); if (e.length > 0 && typeof e[0].SetVariable != "undefined") { return e[0]; } else if (o.length > 0 && typeof o[0].SetVariable != "undefined") { return o[0]; } else if (o.length > 1 && typeof o[1].SetVariable != "undefined") { return o[1]; } } return undefined; } function getPlayers() { var players = []; if (players.length == 0) { var tmp = document.getElementsByTagName('object'); players = tmp; } if (players.length == 0 || players[0].object == null) { var tmp = document.getElementsByTagName('embed'); players = tmp; } return players; } function getIframeHash() { var doc = getHistoryFrame().contentWindow.document; var hash = String(doc.location.search); if (hash.length == 1 && hash.charAt(0) == "?") { hash = ""; } else if (hash.length >= 2 && hash.charAt(0) == "?") { hash = hash.substring(1); } return hash; } /* Get the current location hash excluding the '#' symbol. */ function getHash() { // It would be nice if we could use document.location.hash here, // but it's faulty sometimes. var idx = document.location.href.indexOf('#'); return (idx >= 0) ? document.location.href.substr(idx+1) : ''; } /* Get the current location hash excluding the '#' symbol. */ function setHash(hash) { // It would be nice if we could use document.location.hash here, // but it's faulty sometimes. if (hash == '') hash = '#' document.location.hash = hash; } function createState(baseUrl, newUrl, flexAppUrl) { return { 'baseUrl': baseUrl, 'newUrl': newUrl, 'flexAppUrl': flexAppUrl, 'title': null }; } /* Add a history entry to the browser. * baseUrl: the portion of the location prior to the '#' * newUrl: the entire new URL, including '#' and following fragment * flexAppUrl: the portion of the location following the '#' only */ function addHistoryEntry(baseUrl, newUrl, flexAppUrl) { //delete all the history entries forwardStack = []; if (browser.ie) { //Check to see if we are being asked to do a navigate for the first //history entry, and if so ignore, because it's coming from the creation //of the history iframe if (flexAppUrl == defaultHash && document.location.href == initialHref && window['_ie_firstload']) { currentHref = initialHref; return; } if ((!flexAppUrl || flexAppUrl == defaultHash) && window['_ie_firstload']) { newUrl = baseUrl + '#' + defaultHash; flexAppUrl = defaultHash; } else { // for IE, tell the history frame to go somewhere without a '#' // in order to get this entry into the browser history. getHistoryFrame().src = historyFrameSourcePrefix + flexAppUrl; } setHash(flexAppUrl); } else { //ADR if (backStack.length == 0 && initialState.flexAppUrl == flexAppUrl) { initialState = createState(baseUrl, newUrl, flexAppUrl); } else if(backStack.length > 0 && backStack[backStack.length - 1].flexAppUrl == flexAppUrl) { backStack[backStack.length - 1] = createState(baseUrl, newUrl, flexAppUrl); } if (browser.safari) { // for Safari, submit a form whose action points to the desired URL if (browser.version <= 419.3) { var file = window.location.pathname.toString(); file = file.substring(file.lastIndexOf("/")+1); getFormElement().innerHTML = '<form name="historyForm" action="'+file+'#' + flexAppUrl + '" method="GET"></form>'; //get the current elements and add them to the form var qs = window.location.search.substring(1); var qs_arr = qs.split("&"); for (var i = 0; i < qs_arr.length; i++) { var tmp = qs_arr[i].split("="); var elem = document.createElement("input"); elem.type = "hidden"; elem.name = tmp[0]; elem.value = tmp[1]; document.forms.historyForm.appendChild(elem); } document.forms.historyForm.submit(); } else { top.location.hash = flexAppUrl; } // We also have to maintain the history by hand for Safari historyHash[history.length] = flexAppUrl; _storeStates(); } else { // Otherwise, write an anchor into the page and tell the browser to go there addAnchor(flexAppUrl); setHash(flexAppUrl); } } backStack.push(createState(baseUrl, newUrl, flexAppUrl)); } function _storeStates() { if (browser.safari) { getRememberElement().value = historyHash.join(","); } } function handleBackButton() { //The "current" page is always at the top of the history stack. var current = backStack.pop(); if (!current) { return; } var last = backStack[backStack.length - 1]; if (!last && backStack.length == 0){ last = initialState; } forwardStack.push(current); } function handleForwardButton() { //summary: private method. Do not call this directly. var last = forwardStack.pop(); if (!last) { return; } backStack.push(last); } function handleArbitraryUrl() { //delete all the history entries forwardStack = []; } /* Called periodically to poll to see if we need to detect navigation that has occurred */ function checkForUrlChange() { if (browser.ie) { if (currentHref != document.location.href && currentHref + '#' != document.location.href) { //This occurs when the user has navigated to a specific URL //within the app, and didn't use browser back/forward //IE seems to have a bug where it stops updating the URL it //shows the end-user at this point, but programatically it //appears to be correct. Do a full app reload to get around //this issue. if (browser.version < 7) { currentHref = document.location.href; document.location.reload(); } else { if (getHash() != getIframeHash()) { // this.iframe.src = this.blankURL + hash; var sourceToSet = historyFrameSourcePrefix + getHash(); getHistoryFrame().src = sourceToSet; } } } } if (browser.safari) { // For Safari, we have to check to see if history.length changed. if (currentHistoryLength >= 0 && history.length != currentHistoryLength) { //alert("did change: " + history.length + ", " + historyHash.length + "|" + historyHash[history.length] + "|>" + historyHash.join("|")); // If it did change, then we have to look the old state up // in our hand-maintained array since document.location.hash // won't have changed, then call back into BrowserManager. currentHistoryLength = history.length; var flexAppUrl = historyHash[currentHistoryLength]; if (flexAppUrl == '') { //flexAppUrl = defaultHash; } //ADR: to fix multiple if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { pl[i].browserURLChange(flexAppUrl); } } else { getPlayer().browserURLChange(flexAppUrl); } _storeStates(); } } if (browser.firefox) { if (currentHref != document.location.href) { var bsl = backStack.length; var urlActions = { back: false, forward: false, set: false } if ((window.location.hash == initialHash || window.location.href == initialHref) && (bsl == 1)) { urlActions.back = true; // FIXME: could this ever be a forward button? // we can't clear it because we still need to check for forwards. Ugg. // clearInterval(this.locationTimer); handleBackButton(); } // first check to see if we could have gone forward. We always halt on // a no-hash item. if (forwardStack.length > 0) { if (forwardStack[forwardStack.length-1].flexAppUrl == getHash()) { urlActions.forward = true; handleForwardButton(); } } // ok, that didn't work, try someplace back in the history stack if ((bsl >= 2) && (backStack[bsl - 2])) { if (backStack[bsl - 2].flexAppUrl == getHash()) { urlActions.back = true; handleBackButton(); } } if (!urlActions.back && !urlActions.forward) { var foundInStacks = { back: -1, forward: -1 } for (var i = 0; i < backStack.length; i++) { if (backStack[i].flexAppUrl == getHash() && i != (bsl - 2)) { arbitraryUrl = true; foundInStacks.back = i; } } for (var i = 0; i < forwardStack.length; i++) { if (forwardStack[i].flexAppUrl == getHash() && i != (bsl - 2)) { arbitraryUrl = true; foundInStacks.forward = i; } } handleArbitraryUrl(); } // Firefox changed; do a callback into BrowserManager to tell it. currentHref = document.location.href; var flexAppUrl = getHash(); if (flexAppUrl == '') { //flexAppUrl = defaultHash; } //ADR: to fix multiple if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { pl[i].browserURLChange(flexAppUrl); } } else { getPlayer().browserURLChange(flexAppUrl); } } } //setTimeout(checkForUrlChange, 50); } /* Write an anchor into the page to legitimize it as a URL for Firefox et al. */ function addAnchor(flexAppUrl) { if (document.getElementsByName(flexAppUrl).length == 0) { getAnchorElement().innerHTML += "<a name='" + flexAppUrl + "'>" + flexAppUrl + "</a>"; } } var _initialize = function () { if (browser.ie) { var scripts = document.getElementsByTagName('script'); for (var i = 0, s; s = scripts[i]; i++) { if (s.src.indexOf("history.js") > -1) { var iframe_location = (new String(s.src)).replace("history.js", "historyFrame.html"); } } historyFrameSourcePrefix = iframe_location + "?"; var src = historyFrameSourcePrefix; var iframe = document.createElement("iframe"); iframe.id = 'ie_historyFrame'; iframe.name = 'ie_historyFrame'; //iframe.src = historyFrameSourcePrefix; try { document.body.appendChild(iframe); } catch(e) { setTimeout(function() { document.body.appendChild(iframe); }, 0); } } if (browser.safari) { var rememberDiv = document.createElement("div"); rememberDiv.id = 'safari_rememberDiv'; document.body.appendChild(rememberDiv); rememberDiv.innerHTML = '<input type="text" id="safari_remember_field" style="width: 500px;">'; var formDiv = document.createElement("div"); formDiv.id = 'safari_formDiv'; document.body.appendChild(formDiv); var reloader_content = document.createElement('div'); reloader_content.id = 'safarireloader'; var scripts = document.getElementsByTagName('script'); for (var i = 0, s; s = scripts[i]; i++) { if (s.src.indexOf("history.js") > -1) { html = (new String(s.src)).replace(".js", ".html"); } } reloader_content.innerHTML = '<iframe id="safarireloader-iframe" src="about:blank" frameborder="no" scrolling="no"></iframe>'; document.body.appendChild(reloader_content); reloader_content.style.position = 'absolute'; reloader_content.style.left = reloader_content.style.top = '-9999px'; iframe = reloader_content.getElementsByTagName('iframe')[0]; if (document.getElementById("safari_remember_field").value != "" ) { historyHash = document.getElementById("safari_remember_field").value.split(","); } } if (browser.firefox) { var anchorDiv = document.createElement("div"); anchorDiv.id = 'firefox_anchorDiv'; document.body.appendChild(anchorDiv); } //setTimeout(checkForUrlChange, 50); } return { historyHash: historyHash, backStack: function() { return backStack; }, forwardStack: function() { return forwardStack }, getPlayer: getPlayer, initialize: function(src) { _initialize(src); }, setURL: function(url) { document.location.href = url; }, getURL: function() { return document.location.href; }, getTitle: function() { return document.title; }, setTitle: function(title) { try { backStack[backStack.length - 1].title = title; } catch(e) { } //if on safari, set the title to be the empty string. if (browser.safari) { if (title == "") { try { var tmp = window.location.href.toString(); title = tmp.substring((tmp.lastIndexOf("/")+1), tmp.lastIndexOf("#")); } catch(e) { title = ""; } } } document.title = title; }, setDefaultURL: function(def) { defaultHash = def; def = getHash(); //trailing ? is important else an extra frame gets added to the history //when navigating back to the first page. Alternatively could check //in history frame navigation to compare # and ?. if (browser.ie) { window['_ie_firstload'] = true; var sourceToSet = historyFrameSourcePrefix + def; var func = function() { getHistoryFrame().src = sourceToSet; window.location.replace("#" + def); setInterval(checkForUrlChange, 50); } try { func(); } catch(e) { window.setTimeout(function() { func(); }, 0); } } if (browser.safari) { currentHistoryLength = history.length; if (historyHash.length == 0) { historyHash[currentHistoryLength] = def; var newloc = "#" + def; window.location.replace(newloc); } else { //alert(historyHash[historyHash.length-1]); } //setHash(def); setInterval(checkForUrlChange, 50); } if (browser.firefox || browser.opera) { var reg = new RegExp("#" + def + "$"); if (window.location.toString().match(reg)) { } else { var newloc ="#" + def; window.location.replace(newloc); } setInterval(checkForUrlChange, 50); //setHash(def); } }, /* Set the current browser URL; called from inside BrowserManager to propagate * the application state out to the container. */ setBrowserURL: function(flexAppUrl, objectId) { if (browser.ie && typeof objectId != "undefined") { currentObjectId = objectId; } //fromIframe = fromIframe || false; //fromFlex = fromFlex || false; //alert("setBrowserURL: " + flexAppUrl); //flexAppUrl = (flexAppUrl == "") ? defaultHash : flexAppUrl ; var pos = document.location.href.indexOf('#'); var baseUrl = pos != -1 ? document.location.href.substr(0, pos) : document.location.href; var newUrl = baseUrl + '#' + flexAppUrl; if (document.location.href != newUrl && document.location.href + '#' != newUrl) { currentHref = newUrl; addHistoryEntry(baseUrl, newUrl, flexAppUrl); currentHistoryLength = history.length; } return false; }, browserURLChange: function(flexAppUrl) { var objectId = null; if (browser.ie && currentObjectId != null) { objectId = currentObjectId; } pendingURL = ''; if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { try { pl[i].browserURLChange(flexAppUrl); } catch(e) { } } } else { try { getPlayer(objectId).browserURLChange(flexAppUrl); } catch(e) { } } currentObjectId = null; } } })(); // Initialization // Automated unit testing and other diagnostics function setURL(url) { document.location.href = url; } function backButton() { history.back(); } function forwardButton() { history.forward(); } function goForwardOrBackInHistory(step) { history.go(step); } //BrowserHistoryUtils.addEvent(window, "load", function() { BrowserHistory.initialize(); }); (function(i) { var u =navigator.userAgent;var e=/*@cc_on!@*/false; var st = setTimeout; if(/webkit/i.test(u)){ st(function(){ var dr=document.readyState; if(dr=="loaded"||dr=="complete"){i()} else{st(arguments.callee,10);}},10); } else if((/mozilla/i.test(u)&&!/(compati)/.test(u)) || (/opera/i.test(u))){ document.addEventListener("DOMContentLoaded",i,false); } else if(e){ (function(){ var t=document.createElement('doc:rdy'); try{t.doScroll('left'); i();t=null; }catch(e){st(arguments.callee,0);}})(); } else{ window.onload=i; } })( function() {BrowserHistory.initialize();} );

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• Scripting with the Sun ZFS Storage 7000 Appliance

  - by Geoff Ongley

  The Sun ZFS Storage 7000 appliance has a user friendly and easy to understand graphical web based interface we call the "BUI" or "Browser User Interface".This interface is very useful for many tasks, but in some cases a script (or workflow) may be more appropriate, such as:Repetitive tasksTasks which work on (or obtain information about) a large number of shares or usersTasks which are triggered by an alert threshold (workflows)Tasks where you want a only very basic input, but a consistent output (workflows)The appliance scripting language is based on ECMAscript 3 (close to javascript). I'm not going to cover ECMAscript 3 in great depth (I'm far from an expert here), but I would like to show you some neat things you can do with the appliance, to get you started based on what I have found from my own playing around.I'm making the assumption you have some sort of programming background, and understand variables, arrays, functions to some extent - but of course if something is not clear, please let me know so I can fix it up or clarify it.Variable Declarations and ArraysVariablesECMAScript is a dynamically and weakly typed language. If you don't know what that means, google is your friend - but at a high level it means we can just declare variables with no specific type and on the fly.For example, I can declare a variable and use it straight away in the middle of my code, for example:projects=list();Which makes projects an array of values that are returned from the list(); function (which is usable in most contexts). With this kind of variable, I can do things like:projects.length (this property on array tells you how many objects are in it, good for for loops etc). Alternatively, I could say:projects=3;and now projects is just a simple number.Should we declare variables like this so loosely? In my opinion, the answer is no - I feel it is a better practice to declare variables you are going to use, before you use them - and given them an initial value. You can do so as follows:var myVariable=0;To demonstrate the ability to just randomly assign and change the type of variables, you can create a simple script at the cli as follows (bold for input):fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("Number of projects is: %d\n",projects.length);("." to run)> projects=152;("." to run)> printf("Value of the projects variable as an integer is now: %d\n",projects);("." to run)> .Number of projects is: 7Value of the projects variable as an integer is now: 152You can also confirm this behaviour by checking the typeof variable we are dealing with:fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> projects=152;("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> .var projects is of type objectvar projects is of type numberArraysSo you likely noticed that we have already touched on arrays, as the list(); (in the shares context) stored an array into the 'projects' variable.But what if you want to declare your own array? Easy! This is very similar to Java and other languages, we just instantiate a brand new "Array" object using the keyword new:var myArray = new Array();will create an array called "myArray".A quick example:fishy10:> script("." to run)> testArray = new Array();("." to run)> testArray[0]="This";("." to run)> testArray[1]="is";("." to run)> testArray[2]="just";("." to run)> testArray[3]="a";("." to run)> testArray[4]="test";("." to run)> for (i=0; i < testArray.length; i++)("." to run)> {("." to run)>    printf("Array element %d is %s\n",i,testArray[i]);("." to run)> }("." to run)> .Array element 0 is ThisArray element 1 is isArray element 2 is justArray element 3 is aArray element 4 is testWorking With LoopsFor LoopFor loops are very similar to those you will see in C, java and several other languages. One of the key differences here is, as you were made aware earlier, we can be a bit more sloppy with our variable declarations.The general way you would likely use a for loop is as follows:for (variable; test-case; modifier for variable){}For example, you may wish to declare a variable i as 0; and a MAX_ITERATIONS variable to determine how many times this loop should repeat:var i=0;var MAX_ITERATIONS=10;And then, use this variable to be tested against some case existing (has i reached MAX_ITERATIONS? - if not, increment i using i++);for (i=0; i < MAX_ITERATIONS; i++){ // some work to do}So lets run something like this on the appliance:fishy10:> script("." to run)> var i=0;("." to run)> var MAX_ITERATIONS=10;("." to run)> for (i=0; i < MAX_ITERATIONS; i++)("." to run)> {("." to run)>    printf("The number is %d\n",i);("." to run)> }("." to run)> .The number is 0The number is 1The number is 2The number is 3The number is 4The number is 5The number is 6The number is 7The number is 8The number is 9While LoopWhile loops again are very similar to other languages, we loop "while" a condition is met. For example:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n",counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Counter is 10Loop has ended and Counter is 11So what do we notice here? Something has actually gone wrong - counter will technically be 11 once the loop completes... Why is this?Well, if we have a loop like this, where the 'while' condition that will end the loop may be set based on some other condition(s) existing (such as the counter has reached 10) - we must ensure that we  terminate this iteration of the loop when the condition is met - otherwise the rest of the code will be followed which may not be desirable. In other words, like in other languages, we will only ever check the loop condition once we are ready to perform the next iteration, so any other code after we set "isTen" to be true, will still be executed as we can see it was above.We can avoid this by adding a break into our loop once we know we have set the condition - this will stop the rest of the logic being processed in this iteration (and as such, counter will not be incremented). So lets try that again:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>            break;("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n", counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Loop has ended and Counter is 10Much better!Methods to Obtain and Manipulate DataGet MethodThe get method allows you to get simple properties from an object, for example a quota from a user. The syntax is fairly simple:var myVariable=get('property');An example of where you may wish to use this, is when you are getting a bunch of information about a user (such as quota information when in a shares context):var users=list();for(k=0; k < users.length; k++){     user=users[k];     run('select ' + user);     var username=get('name');     var usage=get('usage');     var quota=get('quota');...Which you can then use to your advantage - to print or manipulate infomation (you could change a user's information with a set method, based on the information returned from the get method). The set method is explained next.Set MethodThe set method can be used in a simple manner, similar to get. The syntax for set is:set('property','value'); // where value is a string, if it was a number, you don't need quotesFor example, we could set the quota on a share as follows (first observing the initial value):fishy10:shares default/test-geoff> script("." to run)> var currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> set('quota','30G');("." to run)> run('commit');("." to run)> currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> .Current Quota is: 0Current Quota is: 32212254720This shows us using both the get and set methods as can be used in scripts, of course when only setting an individual share, the above is overkill - it would be much easier to set it manually at the cli using 'set quota=3G' and then 'commit'.List MethodThe list method can be very powerful, especially in more complex scripts which iterate over large amounts of data and manipulate it if so desired. The general way you will use list is as follows:var myVar=list();Which will make "myVar" an array, containing all the objects in the relevant context (this could be a list of users, shares, projects, etc). You can then gather or manipulate data very easily.We could list all the shares and mountpoints in a given project for example:fishy10:shares another-project> script("." to run)> var shares=list();("." to run)> for (i=0; i < shares.length; i++)("." to run)> {("." to run)>    run('select ' + shares[i]);("." to run)>    var mountpoint=get('mountpoint');("." to run)>    printf("Share %s discovered, has mountpoint %s\n",shares[i],mountpoint);("." to run)>    run('done');("." to run)> }("." to run)> .Share and-another discovered, has mountpoint /export/another-project/and-anotherShare another-share discovered, has mountpoint /export/another-project/another-shareShare bob discovered, has mountpoint /export/another-projectShare more-shares-for-all discovered, has mountpoint /export/another-project/more-shares-for-allShare yep discovered, has mountpoint /export/another-project/yepWriting More Complex and Re-Usable CodeFunctionsThe best way to be able to write more complex code is to use functions to split up repeatable or reusable sections of your code. This also makes your more complex code easier to read and understand for other programmers.We write functions as follows:function functionName(variable1,variable2,...,variableN){}For example, we could have a function that takes a project name as input, and lists shares for that project (assuming we're already in the 'project' context - context is important!):function getShares(proj){        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                printf("Discovered share: %s\n",shares[i]);        }        run('done'); // exit selected project}Commenting your CodeLike any other language, a large part of making it readable and understandable is to comment it. You can use the same comment style as in C and Java amongst other languages.In other words, sngle line comments use://at the beginning of the comment.Multi line comments use:/*at the beginning, and:*/ at the end.For example, here we will use both:fishy10:> script("." to run)> // This is a test comment("." to run)> printf("doing some work...\n");("." to run)> /* This is a multi-line("." to run)> comment which I will span across("." to run)> three lines in total */("." to run)> printf("doing some more work...\n");("." to run)> .doing some work...doing some more work...Your comments do not have to be on their own, they can begin (particularly with single line comments this is handy) at the end of a statement, for examplevar projects=list(); // The variable projects is an array containing all projects on the system.Try and Catch StatementsYou may be used to using try and catch statements in other languages, and they can (and should) be utilised in your code to catch expected or unexpected error conditions, that you do NOT wish to stop your code from executing (if you do not catch these errors, your script will exit!):try{  // do some work}catch(err) // Catch any error that could occur{ // do something here under the error condition}For example, you may wish to only execute some code if a context can be reached. If you can't perform certain actions under certain circumstances, that may be perfectly acceptable.For example if you want to test a condition that only makes sense when looking at a SMB/NFS share, but does not make sense when you hit an iscsi or FC LUN, you don't want to stop all processing of other shares you may not have covered yet.For example we may wish to obtain quota information on all shares for all users on a share (but this makes no sense for a LUN):function getShareQuota(shar) // Get quota for each user of this share{        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","----");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}Running Scripts Remotely over SSHAs you have likely noticed, writing and running scripts for all but the simplest jobs directly on the appliance is not going to be a lot of fun.There's a couple of choices on what you can do here:Create scripts on a remote system and run them over sshCreate scripts, wrapping them in workflow code, so they are stored on the appliance and can be triggered under certain circumstances (like a threshold being reached)We'll cover the first one here, and then cover workflows later on (as these are for the most part just scripts with some wrapper information around them).Creating a SSH Public/Private SSH Key PairLog on to your handy Solaris box (You wouldn't be using any other OS, right? :P) and use ssh-keygen to create a pair of ssh keys. I'm storing this separate to my normal key:[geoff@lightning ~] ssh-keygen -t rsa -b 1024Generating public/private rsa key pair.Enter file in which to save the key (/export/home/geoff/.ssh/id_rsa): /export/home/geoff/.ssh/nas_key_rsaEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /export/home/geoff/.ssh/nas_key_rsa.Your public key has been saved in /export/home/geoff/.ssh/nas_key_rsa.pub.The key fingerprint is:7f:3d:53:f0:2a:5e:8b:2d:94:2a:55:77:66:5c:9b:14 geoff@lightningInstalling the Public Key on the ApplianceOn your Solaris host, observe the public key:[geoff@lightning ~] cat .ssh/nas_key_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc= geoff@lightningNow, copy and paste everything after "ssh-rsa" and before "user@hostname" - in this case, geoff@lightning. That is, this bit:AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc=Logon to your appliance and get into the preferences -> keys area for this user (root):[geoff@lightning ~] ssh [email protected]: Last login: Mon Dec  6 17:13:28 2010 from 192.168.0.2fishy10:> configuration usersfishy10:configuration users> select rootfishy10:configuration users root> preferences fishy10:configuration users root preferences> keysOR do it all in one hit:fishy10:> configuration users select root preferences keysNow, we create a new public key that will be accepted for this user and set the type to RSA:fishy10:configuration users root preferences keys> createfishy10:configuration users root preferences key (uncommitted)> set type=RSASet the key itself using the string copied previously (between ssh-rsa and user@host), and set the key ensuring you put double quotes around it (eg. set key="<key>"):fishy10:configuration users root preferences key (uncommitted)> set key="AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc="Now set the comment for this key (do not use spaces):fishy10:configuration users root preferences key (uncommitted)> set comment="LightningRSAKey" Commit the new key:fishy10:configuration users root preferences key (uncommitted)> commitVerify the key is there:fishy10:configuration users root preferences keys> lsKeys:NAME     MODIFIED              TYPE   COMMENT                                  key-000  2010-10-25 20:56:42   RSA    cycloneRSAKey                           key-001  2010-12-6 17:44:53    RSA    LightningRSAKey                         As you can see, we now have my new key, and a previous key I have created on this appliance.Running your Script over SSH from a Remote SystemHere I have created a basic test script, and saved it as test.ecma3:[geoff@lightning ~] cat test.ecma3 script// This is a test script, By Geoff Ongley 2010.printf("Testing script remotely over ssh\n");.Now, we can run this script remotely with our keyless login:[geoff@lightning ~] ssh -i .ssh/nas_key_rsa root@fishy10 < test.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Testing script remotely over sshPutting it Together - An Example Completed Quota Gathering ScriptSo now we have a lot of the basics to creating a script, let us do something useful, like, find out how much every user is using, on every share on the system (you will recognise some of the code from my previous examples): script/************************************** Quick and Dirty Quota Check script ** Written By Geoff Ongley            ** 25 October 2010                    **************************************/function getUserQuota(usr){        run('select ' + usr);        var username=get('name');        var usage=get('usage');        var quota=get('quota');        var usage_g=usage / 1073741824; // convert bytes to gigabytes        var quota_g=quota / 1073741824; // as above        var quota_percent=0        if (quota > 0)        {                quota_percent=(usage / quota)*(100/1);        }        printf("    %20s        %8.2f           %8.2f           %d%%\n",username,usage_g,quota_g,quota_percent);        run('done'); // done with this selected user}function getShareQuota(shar){        //printf("DEBUG: selecting share %s\n", shar);        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","--------");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}function getShares(proj){        //printf("DEBUG: selecting project %s\n",proj);        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                share=shares[j];                getShareQuota(share);        }        run('done'); // exit selected project}function getProjects(){        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                var project=projects[i];                getShares(project);        }        run('done'); // exit context for all projects}getProjects();.Which can be run as follows, and will print information like this:[geoff@lightning ~/FISHWORKS_SCRIPTS] ssh -i ~/.ssh/nas_key_rsa root@fishy10 < get_quota_utilisation.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Project: another-project  SHARE: and-another                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                 geoffro            0.05            0.00        0%                   Billy            0.10            0.00        0%                    root            0.00            0.00        0%            testing-user            0.05            0.00        0%  SHARE: another-share                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                 geoffro            0.05            0.49        9%            testing-user            0.05            0.02        249%                   Billy            0.10            0.29        33%  SHARE: bob                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%  SHARE: more-shares-for-all                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                   Billy            0.10            0.00        0%            testing-user            0.05            0.00        0%                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%                 geoffro            0.05            0.00        0%  SHARE: yep                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                   Billy            0.10            0.01        999%            testing-user            0.05            0.49        9%                 geoffro            0.05            0.00        0%Project: default  SHARE: Test-LUN    SKIPPING Test-LUN - This is NOT a NFS or CIFs share, not looking for users  SHARE: test-geoff                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                 geoffro            0.05            0.00        0%                    root            3.18           10.00        31%                    uucp            0.00            0.00        0%                  nobody            0.59            0.49        119%^CKilled by signal 2.Creating a WorkflowWorkflows are scripts that we store on the appliance, and can have the script execute either on request (even from the BUI), or on an event such as a threshold being met.Workflow BasicsA workflow allows you to create a simple process that can be executed either via the BUI interface interactively, or by an alert being raised (for some threshold being reached, for example).The basics parameters you will have to set for your "workflow object" (notice you're creating a variable, that embodies ECMAScript) are as follows (parameters is optional):name: A name for this workflowdescription: A Description for the workflowparameters: A set of input parameters (useful when you need user input to execute the workflow)execute: The code, the script itself to execute, which will be function (parameters)With parameters, you can specify things like this (slightly modified sample taken from the System Administration Guide):          ...parameters:        variableParam1:         {                             label: 'Name of Share',                             type: 'String'                  },                  variableParam2                  {                             label: 'Share Size',                             type: 'size'                  },execute: ....};  Note the commas separating the sections of name, parameters, execute, and so on. This is important!Also - there is plenty of properties you can set on the parameters for your workflow, these are described in the Sun ZFS Storage System Administration Guide.Creating a Basic Workflow from a Basic ScriptTo make a basic script into a basic workflow, you need to wrap the following around your script to create a 'workflow' object:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function() {// (basic script goes here, minus the "script" at the beginning, and "." at the end)}};However, it appears (at least in my experience to date) that the workflow object may only be happy with one function in the execute parameter - either that or I'm doing something wrong. As far as I can tell, after execute: you should only have a basic one function context like so:execute: function(){}To deal with this, and to give an example similar to our script earlier, I have created another simple quota check, to show the same basic functionality, but in a workflow format:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function () {        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                run('select ' + projects[i]);                shares=list('filesystem');                printf("Project: %s\n", projects[i]);                for(j=0; j < shares.length; j++)                {                        run('select ' +shares[j]);                        try                        {                                run('users');                                printf("  SHARE: %s\n", shares[j]);                                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","-------");                                users=list();                                for(k=0; k < users.length; k++)                                {                                        run('select ' + users[k]);                                        username=get('name');                                        usage=get('usage');                                        quota=get('quota');                                        usage_g=usage / 1073741824; // convert bytes to gigabytes                                        quota_g=quota / 1073741824; // as above                                        quota_percent=0                                        if (quota > 0)                                        {                                                quota_percent=(usage / quota)*(100/1);                                        }                                        printf("    %20s        %8.2f   %8.2f   %d%%\n",username,usage_g,quota_g,quota_percent);                                        run('done');                                }                                run('done'); // exit user context                        }                        catch(err)                        {                        //      printf("    %s is a LUN, Not looking for users\n", shares[j]);                        }                        run('done'); // exit selected share context                }                run('done'); // exit project context        }        }};SummaryThe Sun ZFS Storage 7000 Appliance offers lots of different and interesting features to Sun/Oracle customers, including the world renowned Analytics. Hopefully the above will help you to think of new creative things you could be doing by taking advantage of one of the other neat features, the internal scripting engine!Some references are below to help you continue learning more, I'll update this post as I do the same! Enjoy...More information on ECMAScript 3A complete reference to ECMAScript 3 which will help you learn more of the details you may be interested in, can be found here:http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdfMore Information on Administering the Sun ZFS Storage 7000The Sun ZFS Storage 7000 System Administration guide can be a useful reference point, and can be found here:http://wikis.sun.com/download/attachments/186238602/2010_Q3_2_ADMIN.pdf

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• C++ - Conway's Game of Life & Stepping Backwards

  - by Gabe

  I was able to create a version Conway's Game of Life that either stepped forward each click, or just ran forward using a timer. (I'm doing this using Qt.) Now, I need to be able to save all previous game grids, so that I can step backwards by clicking a button. I'm trying to use a stack, and it seems like I'm pushing the old gridcells onto the stack correctly. But when I run it in QT, the grids don't change when I click BACK. I've tried different things for the last three hours, to no avail. Any ideas? gridwindow.cpp - My problem should be in here somewhere. Probably the handleBack() func. #include <iostream> #include "gridwindow.h" using namespace std; // Constructor for window. It constructs the three portions of the GUI and lays them out vertically. GridWindow::GridWindow(QWidget *parent,int rows,int cols) : QWidget(parent) { QHBoxLayout *header = setupHeader(); // Setup the title at the top. QGridLayout *grid = setupGrid(rows,cols); // Setup the grid of colored cells in the middle. QHBoxLayout *buttonRow = setupButtonRow(); // Setup the row of buttons across the bottom. QVBoxLayout *layout = new QVBoxLayout(); // Puts everything together. layout->addLayout(header); layout->addLayout(grid); layout->addLayout(buttonRow); setLayout(layout); } // Destructor. GridWindow::~GridWindow() { delete title; } // Builds header section of the GUI. QHBoxLayout* GridWindow::setupHeader() { QHBoxLayout *header = new QHBoxLayout(); // Creates horizontal box. header->setAlignment(Qt::AlignHCenter); this->title = new QLabel("CONWAY'S GAME OF LIFE",this); // Creates big, bold, centered label (title): "Conway's Game of Life." this->title->setAlignment(Qt::AlignHCenter); this->title->setFont(QFont("Arial", 32, QFont::Bold)); header->addWidget(this->title); // Adds widget to layout. return header; // Returns header to grid window. } // Builds the grid of cells. This method populates the grid's 2D array of GridCells with MxN cells. QGridLayout* GridWindow::setupGrid(int rows,int cols) { isRunning = false; QGridLayout *grid = new QGridLayout(); // Creates grid layout. grid->setHorizontalSpacing(0); // No empty spaces. Cells should be contiguous. grid->setVerticalSpacing(0); grid->setSpacing(0); grid->setAlignment(Qt::AlignHCenter); for(int i=0; i < rows; i++) //Each row is a vector of grid cells. { std::vector<GridCell*> row; // Creates new vector for current row. cells.push_back(row); for(int j=0; j < cols; j++) { GridCell *cell = new GridCell(); // Creates and adds new cell to row. cells.at(i).push_back(cell); grid->addWidget(cell,i,j); // Adds to cell to grid layout. Column expands vertically. grid->setColumnStretch(j,1); } grid->setRowStretch(i,1); // Sets row expansion horizontally. } return grid; // Returns grid. } // Builds footer section of the GUI. QHBoxLayout* GridWindow::setupButtonRow() { QHBoxLayout *buttonRow = new QHBoxLayout(); // Creates horizontal box for buttons. buttonRow->setAlignment(Qt::AlignHCenter); // Clear Button - Clears cell; sets them all to DEAD/white. QPushButton *clearButton = new QPushButton("CLEAR"); clearButton->setFixedSize(100,25); connect(clearButton, SIGNAL(clicked()), this, SLOT(handlePause())); // Pauses timer before clearing. connect(clearButton, SIGNAL(clicked()), this, SLOT(handleClear())); // Connects to clear function to make all cells DEAD/white. buttonRow->addWidget(clearButton); // Forward Button - Steps one step forward. QPushButton *forwardButton = new QPushButton("FORWARD"); forwardButton->setFixedSize(100,25); connect(forwardButton, SIGNAL(clicked()), this, SLOT(handleForward())); // Signals to handleForward function.. buttonRow->addWidget(forwardButton); // Back Button - Steps one step backward. QPushButton *backButton = new QPushButton("BACK"); backButton->setFixedSize(100,25); connect(backButton, SIGNAL(clicked()), this, SLOT(handleBack())); // Signals to handleBack funciton. buttonRow->addWidget(backButton); // Start Button - Starts game when user clicks. Or, resumes game after being paused. QPushButton *startButton = new QPushButton("START/RESUME"); startButton->setFixedSize(100,25); connect(startButton, SIGNAL(clicked()), this, SLOT(handlePause())); // Deletes current timer if there is one. Then restarts everything. connect(startButton, SIGNAL(clicked()), this, SLOT(handleStart())); // Signals to handleStart function. buttonRow->addWidget(startButton); // Pause Button - Pauses simulation of game. QPushButton *pauseButton = new QPushButton("PAUSE"); pauseButton->setFixedSize(100,25); connect(pauseButton, SIGNAL(clicked()), this, SLOT(handlePause())); // Signals to pause function which pauses timer. buttonRow->addWidget(pauseButton); // Quit Button - Exits program. QPushButton *quitButton = new QPushButton("EXIT"); quitButton->setFixedSize(100,25); connect(quitButton, SIGNAL(clicked()), qApp, SLOT(quit())); // Signals the quit slot which ends the program. buttonRow->addWidget(quitButton); return buttonRow; // Returns bottom of layout. } /* SLOT method for handling clicks on the "clear" button. Receives "clicked" signals on the "Clear" button and sets all cells to DEAD. */ void GridWindow::handleClear() { for(unsigned int row=0; row < cells.size(); row++) // Loops through current rows' cells. { for(unsigned int col=0; col < cells[row].size(); col++) // Loops through the rows'columns' cells. { GridCell *cell = cells[row][col]; // Grab the current cell & set its value to dead. cell->setType(DEAD); } } } /* SLOT method for handling clicks on the "start" button. Receives "clicked" signals on the "start" button and begins game simulation. */ void GridWindow::handleStart() { isRunning = true; // It is running. Sets isRunning to true. this->timer = new QTimer(this); // Creates new timer. connect(this->timer, SIGNAL(timeout()), this, SLOT(timerFired())); // Connect "timerFired" method class to the "timeout" signal fired by the timer. this->timer->start(500); // Timer to fire every 500 milliseconds. } /* SLOT method for handling clicks on the "pause" button. Receives "clicked" signals on the "pause" button and stops the game simulation. */ void GridWindow::handlePause() { if(isRunning) // If it is running... this->timer->stop(); // Stops the timer. isRunning = false; // Set to false. } void GridWindow::handleForward() { if(isRunning); // If it's running, do nothing. else timerFired(); // It not running, step forward one step. } void GridWindow::handleBack() { std::vector<std::vector<GridCell*> > cells2; if(isRunning); // If it's running, do nothing. else if(backStack.empty()) cout << "EMPTYYY" << endl; else { cells2 = backStack.peek(); for (unsigned int f = 0; f < cells.size(); f++) // Loop through cells' rows. { for (unsigned int g = 0; g < cells.at(f).size(); g++) // Loop through cells columns. { cells[f][g]->setType(cells2[f][g]->getType()); // Set cells[f][g]'s type to cells2[f][g]'s type. } } cout << "PRE=POP" << endl; backStack.pop(); cout << "OYYYY" << endl; } } // Accessor method - Gets the 2D vector of grid cells. std::vector<std::vector<GridCell*> >& GridWindow::getCells() { return this->cells; } /* TimerFired function: 1) 2D-Vector cells2 is declared. 2) cells2 is initliazed with loops/push_backs so that all its cells are DEAD. 3) We loop through cells, and count the number of LIVE neighbors next to a given cell. --> Depending on how many cells are living, we choose if the cell should be LIVE or DEAD in the next simulation, according to the rules. -----> We save the cell type in cell2 at the same indice (the same row and column cell in cells2). 4) After check all the cells (and save the next round values in cells 2), we set cells's gridcells equal to cells2 gridcells. --> This causes the cells to be redrawn with cells2 types (white or black). */ void GridWindow::timerFired() { backStack.push(cells); std::vector<std::vector<GridCell*> > cells2; // Holds new values for 2D vector. These are the next simulation round of cell types. for(unsigned int i = 0; i < cells.size(); i++) // Loop through the rows of cells2. (Same size as cells' rows.) { vector<GridCell*> row; // Creates Gridcell* vector to push_back into cells2. cells2.push_back(row); // Pushes back row vectors into cells2. for(unsigned int j = 0; j < cells[i].size(); j++) // Loop through the columns (the cells in each row). { GridCell *cell = new GridCell(); // Creates new GridCell. cell->setType(DEAD); // Sets cell type to DEAD/white. cells2.at(i).push_back(cell); // Pushes back the DEAD cell into cells2. } // This makes a gridwindow the same size as cells with all DEAD cells. } for (unsigned int m = 0; m < cells.size(); m++) // Loop through cells' rows. { for (unsigned int n = 0; n < cells.at(m).size(); n++) // Loop through cells' columns. { unsigned int neighbors = 0; // Counter for number of LIVE neighbors for a given cell. // We know check all different variations of cells[i][j] to count the number of living neighbors for each cell. // We check m > 0 and/or n > 0 to make sure we don't access negative indexes (ex: cells[-1][0].) // We check m < size to make sure we don't try to access rows out of the vector (ex: row 5, if only 4 rows). // We check n < row size to make sure we don't access column item out of the vector (ex: 10th item in a column of only 9 items). // If we find that the Type = 1 (it is LIVE), then we add 1 to the neighbor. // Else - we add nothing to the neighbor counter. // Neighbor is the number of LIVE cells next to the current cell. if(m > 0 && n > 0) { if (cells[m-1][n-1]->getType() == 1) neighbors += 1; } if(m > 0) { if (cells[m-1][n]->getType() == 1) neighbors += 1; if(n < (cells.at(m).size() - 1)) { if (cells[m-1][n+1]->getType() == 1) neighbors += 1; } } if(n > 0) { if (cells[m][n-1]->getType() == 1) neighbors += 1; if(m < (cells.size() - 1)) { if (cells[m+1][n-1]->getType() == 1) neighbors += 1; } } if(n < (cells.at(m).size() - 1)) { if (cells[m][n+1]->getType() == 1) neighbors += 1; } if(m < (cells.size() - 1)) { if (cells[m+1][n]->getType() == 1) neighbors += 1; } if(m < (cells.size() - 1) && n < (cells.at(m).size() - 1)) { if (cells[m+1][n+1]->getType() == 1) neighbors += 1; } // Done checking number of neighbors for cells[m][n] // Now we change cells2 if it should switch in the next simulation step. // cells2 holds the values of what cells should be on the next iteration of the game. // We can't change cells right now, or it would through off our other cell values. // Apply game rules to cells: Create new, updated grid with the roundtwo vector. // Note - LIVE is 1; DEAD is 0. if (cells[m][n]->getType() == 1 && neighbors < 2) // If cell is LIVE and has less than 2 LIVE neighbors -> Set to DEAD. cells2[m][n]->setType(DEAD); else if (cells[m][n]->getType() == 1 && neighbors > 3) // If cell is LIVE and has more than 3 LIVE neighbors -> Set to DEAD. cells2[m][n]->setType(DEAD); else if (cells[m][n]->getType() == 1 && (neighbors == 2 || neighbors == 3)) // If cell is LIVE and has 2 or 3 LIVE neighbors -> Set to LIVE. cells2[m][n]->setType(LIVE); else if (cells[m][n]->getType() == 0 && neighbors == 3) // If cell is DEAD and has 3 LIVE neighbors -> Set to LIVE. cells2[m][n]->setType(LIVE); } } // Now we've gone through all of cells, and saved the new values in cells2. // Now we loop through cells and set all the cells' types to those of cells2. for (unsigned int f = 0; f < cells.size(); f++) // Loop through cells' rows. { for (unsigned int g = 0; g < cells.at(f).size(); g++) // Loop through cells columns. { cells[f][g]->setType(cells2[f][g]->getType()); // Set cells[f][g]'s type to cells2[f][g]'s type. } } } stack.h - Here's my stack. #ifndef STACK_H_ #define STACK_H_ #include <iostream> #include "node.h" template <typename T> class Stack { private: Node<T>* top; int listSize; public: Stack(); int size() const; bool empty() const; void push(const T& value); void pop(); T& peek() const; }; template <typename T> Stack<T>::Stack() : top(NULL) { listSize = 0; } template <typename T> int Stack<T>::size() const { return listSize; } template <typename T> bool Stack<T>::empty() const { if(listSize == 0) return true; else return false; } template <typename T> void Stack<T>::push(const T& value) { Node<T>* newOne = new Node<T>(value); newOne->next = top; top = newOne; listSize++; } template <typename T> void Stack<T>::pop() { Node<T>* oldT = top; top = top->next; delete oldT; listSize--; } template <typename T> T& Stack<T>::peek() const { return top->data; // Returns data in top item. } #endif gridcell.cpp - Gridcell implementation #include <iostream> #include "gridcell.h" using namespace std; // Constructor: Creates a grid cell. GridCell::GridCell(QWidget *parent) : QFrame(parent) { this->type = DEAD; // Default: Cell is DEAD (white). setFrameStyle(QFrame::Box); // Set the frame style. This is what gives each box its black border. this->button = new QPushButton(this); //Creates button that fills entirety of each grid cell. this->button->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding); // Expands button to fill space. this->button->setMinimumSize(19,19); //width,height // Min height and width of button. QHBoxLayout *layout = new QHBoxLayout(); //Creates a simple layout to hold our button and add the button to it. layout->addWidget(this->button); setLayout(layout); layout->setStretchFactor(this->button,1); // Lets the buttons expand all the way to the edges of the current frame with no space leftover layout->setContentsMargins(0,0,0,0); layout->setSpacing(0); connect(this->button,SIGNAL(clicked()),this,SLOT(handleClick())); // Connects clicked signal with handleClick slot. redrawCell(); // Calls function to redraw (set new type for) the cell. } // Basic destructor. GridCell::~GridCell() { delete this->button; } // Accessor for the cell type. CellType GridCell::getType() const { return(this->type); } // Mutator for the cell type. Also has the side effect of causing the cell to be redrawn on the GUI. void GridCell::setType(CellType type) { this->type = type; redrawCell(); // Sets type and redraws cell. } // Handler slot for button clicks. This method is called whenever the user clicks on this cell in the grid. void GridCell::handleClick() { // When clicked on... if(this->type == DEAD) // If type is DEAD (white), change to LIVE (black). type = LIVE; else type = DEAD; // If type is LIVE (black), change to DEAD (white). setType(type); // Sets new type (color). setType Calls redrawCell() to recolor. } // Method to check cell type and return the color of that type. Qt::GlobalColor GridCell::getColorForCellType() { switch(this->type) { default: case DEAD: return Qt::white; case LIVE: return Qt::black; } } // Helper method. Forces current cell to be redrawn on the GUI. Called whenever the setType method is invoked. void GridCell::redrawCell() { Qt::GlobalColor gc = getColorForCellType(); //Find out what color this cell should be. this->button->setPalette(QPalette(gc,gc)); //Force the button in the cell to be the proper color. this->button->setAutoFillBackground(true); this->button->setFlat(true); //Force QT to NOT draw the borders on the button } Thanks a lot. Let me know if you need anything else.

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• NullPointerException when linking to Service that uses ContentProvider

  - by Danny Chia

  H.i everyone, this is my first post here! Anyways, I'm trying to write a "todo list" application. It stores the data in a ContentProvider, which is accessed via a Service. However, my app crashes at launch. My code is below: Manifest file: <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.examples.todolist" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="True"> <activity android:name=".ToDoList" android:label="@string/app_name" android:theme="@style/ToDoTheme"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name="TodoService"/> <provider android:name="TodoProvider" android:authorities="com.examples.provider.todolist" /> </application> <uses-sdk android:minSdkVersion="7" /> </manifest> ToDoList.java: package com.examples.todolist; import com.examples.todolist.TodoService.LocalBinder; import java.util.ArrayList; import java.util.Date; import android.app.Activity; import android.content.SharedPreferences; import android.database.Cursor; import android.os.AsyncTask; import android.os.Bundle; import android.view.ContextMenu; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.os.IBinder; import android.view.KeyEvent; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnKeyListener; import android.widget.AdapterView; import android.widget.EditText; import android.widget.ListView; import android.widget.Toast; public class ToDoList extends Activity { static final private int ADD_NEW_TODO = Menu.FIRST; static final private int REMOVE_TODO = Menu.FIRST + 1; private static final String TEXT_ENTRY_KEY = "TEXT_ENTRY_KEY"; private static final String ADDING_ITEM_KEY = "ADDING_ITEM_KEY"; private static final String SELECTED_INDEX_KEY = "SELECTED_INDEX_KEY"; private boolean addingNew = false; private ArrayList<ToDoItem> todoItems; private ListView myListView; private EditText myEditText; private ToDoItemAdapter aa; int entries = 0; int notifs = 0; //ToDoDBAdapter toDoDBAdapter; Cursor toDoListCursor; TodoService mService; boolean mBound = false; /** Called when the activity is first created. */ public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); myListView = (ListView)findViewById(R.id.myListView); myEditText = (EditText)findViewById(R.id.myEditText); todoItems = new ArrayList<ToDoItem>(); int resID = R.layout.todolist_item; aa = new ToDoItemAdapter(this, resID, todoItems); myListView.setAdapter(aa); myEditText.setOnKeyListener(new OnKeyListener() { public boolean onKey(View v, int keyCode, KeyEvent event) { if (event.getAction() == KeyEvent.ACTION_DOWN) if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) { ToDoItem newItem = new ToDoItem(myEditText.getText().toString(), 0); mService.insertTask(newItem); updateArray(); myEditText.setText(""); entries++; Toast.makeText(ToDoList.this, "Entry added", Toast.LENGTH_SHORT).show(); aa.notifyDataSetChanged(); cancelAdd(); return true; } return false; } }); registerForContextMenu(myListView); restoreUIState(); populateTodoList(); } private void populateTodoList() { // Get all the todo list items from the database. toDoListCursor = mService. getAllToDoItemsCursor(); startManagingCursor(toDoListCursor); // Update the array. updateArray(); Toast.makeText(this, "Todo list retrieved", Toast.LENGTH_SHORT).show(); } private void updateArray() { toDoListCursor.requery(); todoItems.clear(); if (toDoListCursor.moveToFirst()) do { String task = toDoListCursor.getString(toDoListCursor.getColumnIndex(ToDoDBAdapter.KEY_TASK)); long created = toDoListCursor.getLong(toDoListCursor.getColumnIndex(ToDoDBAdapter.KEY_CREATION_DATE)); int taskid = toDoListCursor.getInt(toDoListCursor.getColumnIndex(ToDoDBAdapter.KEY_ID)); ToDoItem newItem = new ToDoItem(task, new Date(created), taskid); todoItems.add(0, newItem); } while(toDoListCursor.moveToNext()); aa.notifyDataSetChanged(); } private void restoreUIState() { // Get the activity preferences object. SharedPreferences settings = getPreferences(0); // Read the UI state values, specifying default values. String text = settings.getString(TEXT_ENTRY_KEY, ""); Boolean adding = settings.getBoolean(ADDING_ITEM_KEY, false); // Restore the UI to the previous state. if (adding) { addNewItem(); myEditText.setText(text); } } @Override public void onSaveInstanceState(Bundle outState) { outState.putInt(SELECTED_INDEX_KEY, myListView.getSelectedItemPosition()); super.onSaveInstanceState(outState); } @Override public void onRestoreInstanceState(Bundle savedInstanceState) { int pos = -1; if (savedInstanceState != null) if (savedInstanceState.containsKey(SELECTED_INDEX_KEY)) pos = savedInstanceState.getInt(SELECTED_INDEX_KEY, -1); myListView.setSelection(pos); } @Override protected void onPause() { super.onPause(); // Get the activity preferences object. SharedPreferences uiState = getPreferences(0); // Get the preferences editor. SharedPreferences.Editor editor = uiState.edit(); // Add the UI state preference values. editor.putString(TEXT_ENTRY_KEY, myEditText.getText().toString()); editor.putBoolean(ADDING_ITEM_KEY, addingNew); // Commit the preferences. editor.commit(); } @Override public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); // Create and add new menu items. MenuItem itemAdd = menu.add(0, ADD_NEW_TODO, Menu.NONE, R.string.add_new); MenuItem itemRem = menu.add(0, REMOVE_TODO, Menu.NONE, R.string.remove); // Assign icons itemAdd.setIcon(R.drawable.add_new_item); itemRem.setIcon(R.drawable.remove_item); // Allocate shortcuts to each of them. itemAdd.setShortcut('0', 'a'); itemRem.setShortcut('1', 'r'); return true; } @Override public boolean onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); int idx = myListView.getSelectedItemPosition(); String removeTitle = getString(addingNew ? R.string.cancel : R.string.remove); MenuItem removeItem = menu.findItem(REMOVE_TODO); removeItem.setTitle(removeTitle); removeItem.setVisible(addingNew || idx > -1); return true; } @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); menu.setHeaderTitle("Selected To Do Item"); menu.add(0, REMOVE_TODO, Menu.NONE, R.string.remove); } @Override public boolean onOptionsItemSelected(MenuItem item) { super.onOptionsItemSelected(item); int index = myListView.getSelectedItemPosition(); switch (item.getItemId()) { case (REMOVE_TODO): { if (addingNew) { cancelAdd(); } else { removeItem(index); } return true; } case (ADD_NEW_TODO): { addNewItem(); return true; } } return false; } @Override public boolean onContextItemSelected(MenuItem item) { super.onContextItemSelected(item); switch (item.getItemId()) { case (REMOVE_TODO): { AdapterView.AdapterContextMenuInfo menuInfo; menuInfo =(AdapterView.AdapterContextMenuInfo)item.getMenuInfo(); int index = menuInfo.position; removeItem(index); return true; } } return false; } @Override public void onDestroy() { super.onDestroy(); } private void cancelAdd() { addingNew = false; myEditText.setVisibility(View.GONE); } private void addNewItem() { addingNew = true; myEditText.setVisibility(View.VISIBLE); myEditText.requestFocus(); } private void removeItem(int _index) { // Items are added to the listview in reverse order, so invert the index. //toDoDBAdapter.removeTask(todoItems.size()-_index); ToDoItem item = todoItems.get(_index); final long selectedId = item.getTaskId(); mService.removeTask(selectedId); entries--; Toast.makeText(this, "Entry deleted", Toast.LENGTH_SHORT).show(); updateArray(); } @Override protected void onStart() { super.onStart(); Intent intent = new Intent(this, TodoService.class); bindService(intent, mConnection, Context.BIND_AUTO_CREATE); } @Override protected void onStop() { super.onStop(); // Unbind from the service if (mBound) { unbindService(mConnection); mBound = false; } } private ServiceConnection mConnection = new ServiceConnection() { public void onServiceConnected(ComponentName className, IBinder service) { LocalBinder binder = (LocalBinder) service; mService = binder.getService(); mBound = true; } public void onServiceDisconnected(ComponentName arg0) { mBound = false; } }; public class TimedToast extends AsyncTask<Long, Integer, Integer> { @Override protected Integer doInBackground(Long... arg0) { if (notifs < 15) { try { Toast.makeText(ToDoList.this, entries + " entries left", Toast.LENGTH_SHORT).show(); notifs++; Thread.sleep(20000); } catch (InterruptedException e) { } } return 0; } } } TodoService.java: package com.examples.todolist; import android.app.Service; import android.content.ContentResolver; import android.content.ContentValues; import android.content.Intent; import android.database.Cursor; import android.os.Binder; import android.os.IBinder; public class TodoService extends Service { private final IBinder mBinder = new LocalBinder(); @Override public IBinder onBind(Intent arg0) { return mBinder; } public class LocalBinder extends Binder { TodoService getService() { return TodoService.this; } } public void insertTask(ToDoItem _task) { ContentResolver cr = getContentResolver(); ContentValues values = new ContentValues(); values.put(TodoProvider.KEY_CREATION_DATE, _task.getCreated().getTime()); values.put(TodoProvider.KEY_TASK, _task.getTask()); cr.insert(TodoProvider.CONTENT_URI, values); } public void updateTask(ToDoItem _task) { long tid = _task.getTaskId(); ContentResolver cr = getContentResolver(); ContentValues values = new ContentValues(); values.put(TodoProvider.KEY_TASK, _task.getTask()); cr.update(TodoProvider.CONTENT_URI, values, TodoProvider.KEY_ID + "=" + tid, null); } public void removeTask(long tid) { ContentResolver cr = getContentResolver(); cr.delete(TodoProvider.CONTENT_URI, TodoProvider.KEY_ID + "=" + tid, null); } public Cursor getAllToDoItemsCursor() { ContentResolver cr = getContentResolver(); return cr.query(TodoProvider.CONTENT_URI, null, null, null, null); } } TodoProvider.java: package com.examples.todolist; import android.content.*; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteOpenHelper; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteQueryBuilder; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.net.Uri; import android.text.TextUtils; import android.util.Log; public class TodoProvider extends ContentProvider { public static final Uri CONTENT_URI = Uri.parse("content://com.examples.provider.todolist/todo"); @Override public boolean onCreate() { Context context = getContext(); todoHelper dbHelper = new todoHelper(context, DATABASE_NAME, null, DATABASE_VERSION); todoDB = dbHelper.getWritableDatabase(); return (todoDB == null) ? false : true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sort) { SQLiteQueryBuilder tb = new SQLiteQueryBuilder(); tb.setTables(TODO_TABLE); // If this is a row query, limit the result set to the passed in row. switch (uriMatcher.match(uri)) { case TASK_ID: tb.appendWhere(KEY_ID + "=" + uri.getPathSegments().get(1)); break; default: break; } // If no sort order is specified sort by date / time String orderBy; if (TextUtils.isEmpty(sort)) { orderBy = KEY_ID; } else { orderBy = sort; } // Apply the query to the underlying database. Cursor c = tb.query(todoDB, projection, selection, selectionArgs, null, null, orderBy); // Register the contexts ContentResolver to be notified if // the cursor result set changes. c.setNotificationUri(getContext().getContentResolver(), uri); // Return a cursor to the query result. return c; } @Override public Uri insert(Uri _uri, ContentValues _initialValues) { // Insert the new row, will return the row number if // successful. long rowID = todoDB.insert(TODO_TABLE, "task", _initialValues); // Return a URI to the newly inserted row on success. if (rowID > 0) { Uri uri = ContentUris.withAppendedId(CONTENT_URI, rowID); getContext().getContentResolver().notifyChange(uri, null); return uri; } throw new SQLException("Failed to insert row into " + _uri); } @Override public int delete(Uri uri, String where, String[] whereArgs) { int count; switch (uriMatcher.match(uri)) { case TASKS: count = todoDB.delete(TODO_TABLE, where, whereArgs); break; case TASK_ID: String segment = uri.getPathSegments().get(1); count = todoDB.delete(TODO_TABLE, KEY_ID + "=" + segment + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs); break; default: throw new IllegalArgumentException("Unsupported URI: " + uri); } getContext().getContentResolver().notifyChange(uri, null); return count; } @Override public int update(Uri uri, ContentValues values, String where, String[] whereArgs) { int count; switch (uriMatcher.match(uri)) { case TASKS: count = todoDB.update(TODO_TABLE, values, where, whereArgs); break; case TASK_ID: String segment = uri.getPathSegments().get(1); count = todoDB.update(TODO_TABLE, values, KEY_ID + "=" + segment + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs); break; default: throw new IllegalArgumentException("Unknown URI " + uri); } getContext().getContentResolver().notifyChange(uri, null); return count; } @Override public String getType(Uri uri) { switch (uriMatcher.match(uri)) { case TASKS: return "vnd.android.cursor.dir/vnd.examples.task"; case TASK_ID: return "vnd.android.cursor.item/vnd.examples.task"; default: throw new IllegalArgumentException("Unsupported URI: " + uri); } } // Create the constants used to differentiate between the different URI // requests. private static final int TASKS = 1; private static final int TASK_ID = 2; private static final UriMatcher uriMatcher; // Allocate the UriMatcher object, where a URI ending in 'tasks' will // correspond to a request for all tasks, and 'tasks' with a // trailing '/[rowID]' will represent a single task row. static { uriMatcher = new UriMatcher(UriMatcher.NO_MATCH); uriMatcher.addURI("com.examples.provider.Todolist", "tasks", TASKS); uriMatcher.addURI("com.examples.provider.Todolist", "tasks/#", TASK_ID); } //The underlying database private SQLiteDatabase todoDB; private static final String TAG = "TodoProvider"; private static final String DATABASE_NAME = "todolist.db"; private static final int DATABASE_VERSION = 1; private static final String TODO_TABLE = "todolist"; // Column Names public static final String KEY_ID = "_id"; public static final String KEY_TASK = "task"; public static final String KEY_CREATION_DATE = "date"; public long insertTask(ToDoItem _task) { // Create a new row of values to insert. ContentValues newTaskValues = new ContentValues(); // Assign values for each row. newTaskValues.put(KEY_TASK, _task.getTask()); newTaskValues.put(KEY_CREATION_DATE, _task.getCreated().getTime()); // Insert the row. return todoDB.insert(TODO_TABLE, null, newTaskValues); } public boolean updateTask(long _rowIndex, String _task) { ContentValues newValue = new ContentValues(); newValue.put(KEY_TASK, _task); return todoDB.update(TODO_TABLE, newValue, KEY_ID + "=" + _rowIndex, null) > 0; } public boolean removeTask(long _rowIndex) { return todoDB.delete(TODO_TABLE, KEY_ID + "=" + _rowIndex, null) > 0; } // Helper class for opening, creating, and managing database version control private static class todoHelper extends SQLiteOpenHelper { private static final String DATABASE_CREATE = "create table " + TODO_TABLE + " (" + KEY_ID + " integer primary key autoincrement, " + KEY_TASK + " TEXT, " + KEY_CREATION_DATE + " INTEGER);"; public todoHelper(Context cn, String name, CursorFactory cf, int ver) { super(cn, name, cf, ver); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TODO_TABLE); onCreate(db); } } } I've omitted the other files as I'm sure they are correct. When I run the program, LogCat shows that the NullPointerException occurs in populateTodoList(), at toDoListCursor = mService.getAllToDoItemsCursor(). mService is the Cursor object returned by TodoService. I've added the service to the Manifest file, but I still cannot find out why it's causing an exception. Thanks in advance.

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