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• Top 50 ASP.Net Interview Questions & Answers

  - by Samir R. Bhogayta

  1. What is ASP.Net? It is a framework developed by Microsoft on which we can develop new generation web sites using web forms(aspx), MVC, HTML, Javascript, CSS etc. Its successor of Microsoft Active Server Pages(ASP). Currently there is ASP.NET 4.0, which is used to develop web sites. There are various page extensions provided by Microsoft that are being used for web site development. Eg: aspx, asmx, ascx, ashx, cs, vb, html, xml etc. 2. What’s the use of Response.Output.Write()? We can write formatted output  using Response.Output.Write(). 3. In which event of page cycle is the ViewState available?   After the Init() and before the Page_Load(). 4. What is the difference between Server.Transfer and Response.Redirect?   In Server.Transfer page processing transfers from one page to the other page without making a round-trip back to the client’s browser.  This provides a faster response with a little less overhead on the server.  The clients url history list or current url Server does not update in case of Server.Transfer. Response.Redirect is used to redirect the user’s browser to another page or site.  It performs trip back to the client where the client’s browser is redirected to the new page.  The user’s browser history list is updated to reflect the new address. 5. From which base class all Web Forms are inherited? Page class.  6. What are the different validators in ASP.NET? Required field Validator Range  Validator Compare Validator Custom Validator Regular expression Validator Summary Validator 7. Which validator control you use if you need to make sure the values in two different controls matched? Compare Validator control. 8. What is ViewState? ViewState is used to retain the state of server-side objects between page post backs. 9. Where the viewstate is stored after the page postback? ViewState is stored in a hidden field on the page at client side.  ViewState is transported to the client and back to the server, and is not stored on the server or any other external source. 10. How long the items in ViewState exists? They exist for the life of the current page. 11. What are the different Session state management options available in ASP.NET? In-Process Out-of-Process. In-Process stores the session in memory on the web server. Out-of-Process Session state management stores data in an external server.  The external server may be either a SQL Server or a State Server.  All objects stored in session are required to be serializable for Out-of-Process state management. 12. How you can add an event handler?  Using the Attributes property of server side control. e.g. [csharp] btnSubmit.Attributes.Add(“onMouseOver”,”JavascriptCode();”) [/csharp] 13. What is caching? Caching is a technique used to increase performance by keeping frequently accessed data or files in memory. The request for a cached file/data will be accessed from cache instead of actual location of that file. 14. What are the different types of caching? ASP.NET has 3 kinds of caching : Output Caching, Fragment Caching, Data Caching. 15. Which type if caching will be used if we want to cache the portion of a page instead of whole page? Fragment Caching: It caches the portion of the page generated by the request. For that, we can create user controls with the below code: [xml] <%@ OutputCache Duration=”120? VaryByParam=”CategoryID;SelectedID”%> [/xml] 16. List the events in page life cycle.   1) Page_PreInit 2) Page_Init 3) Page_InitComplete 4) Page_PreLoad 5) Page_Load 6) Page_LoadComplete 7) Page_PreRender 8)Render 17. Can we have a web application running without web.Config file?   Yes 18. Is it possible to create web application with both webforms and mvc? Yes. We have to include below mvc assembly references in the web forms application to create hybrid application. [csharp] System.Web.Mvc System.Web.Razor System.ComponentModel.DataAnnotations [/csharp] 19. Can we add code files of different languages in App_Code folder?   No. The code files must be in same language to be kept in App_code folder. 20. What is Protected Configuration? It is a feature used to secure connection string information. 21. Write code to send e-mail from an ASP.NET application? [csharp] MailMessage mailMess = new MailMessage (); mailMess.From = “[email protected]”; mailMess.To = “[email protected]”; mailMess.Subject = “Test email”; mailMess.Body = “Hi This is a test mail.”; SmtpMail.SmtpServer = “localhost”; SmtpMail.Send (mailMess); [/csharp] MailMessage and SmtpMail are classes defined System.Web.Mail namespace.  22. How can we prevent browser from caching an ASPX page?   We can SetNoStore on HttpCachePolicy object exposed by the Response object’s Cache property: [csharp] Response.Cache.SetNoStore (); Response.Write (DateTime.Now.ToLongTimeString ()); [/csharp] 23. What is the good practice to implement validations in aspx page? Client-side validation is the best way to validate data of a web page. It reduces the network traffic and saves server resources. 24. What are the event handlers that we can have in Global.asax file? Application Events: Application_Start , Application_End, Application_AcquireRequestState, Application_AuthenticateRequest, Application_AuthorizeRequest, Application_BeginRequest, Application_Disposed,  Application_EndRequest, Application_Error, Application_PostRequestHandlerExecute, Application_PreRequestHandlerExecute, Application_PreSendRequestContent, Application_PreSendRequestHeaders, Application_ReleaseRequestState, Application_ResolveRequestCache, Application_UpdateRequestCache Session Events: Session_Start,Session_End 25. Which protocol is used to call a Web service? HTTP Protocol 26. Can we have multiple web config files for an asp.net application? Yes. 27. What is the difference between web config and machine config? Web config file is specific to a web application where as machine config is specific to a machine or server. There can be multiple web config files into an application where as we can have only one machine config file on a server. 28.  Explain role based security ?   Role Based Security used to implement security based on roles assigned to user groups in the organization. Then we can allow or deny users based on their role in the organization. Windows defines several built-in groups, including Administrators, Users, and Guests. [xml] <AUTHORIZATION>< authorization > < allow roles=”Domain_Name\Administrators” / >   < !– Allow Administrators in domain. — > < deny users=”*”  / >                            < !– Deny anyone else. — > < /authorization > [/xml] 29. What is Cross Page Posting? When we click submit button on a web page, the page post the data to the same page. The technique in which we post the data to different pages is called Cross Page posting. This can be achieved by setting POSTBACKURL property of  the button that causes the postback. Findcontrol method of PreviousPage can be used to get the posted values on the page to which the page has been posted. 30. How can we apply Themes to an asp.net application? We can specify the theme in web.config file. Below is the code example to apply theme: [xml] <configuration> <system.web> <pages theme=”Windows7? /> </system.web> </configuration> [/xml] 31: What is RedirectPermanent in ASP.Net?   RedirectPermanent Performs a permanent redirection from the requested URL to the specified URL. Once the redirection is done, it also returns 301 Moved Permanently responses. 32: What is MVC? MVC is a framework used to create web applications. The web application base builds on  Model-View-Controller pattern which separates the application logic from UI, and the input and events from the user will be controlled by the Controller. 33. Explain the working of passport authentication. First of all it checks passport authentication cookie. If the cookie is not available then the application redirects the user to Passport Sign on page. Passport service authenticates the user details on sign on page and if valid then stores the authenticated cookie on client machine and then redirect the user to requested page 34. What are the advantages of Passport authentication? All the websites can be accessed using single login credentials. So no need to remember login credentials for each web site. Users can maintain his/ her information in a single location. 35. What are the asp.net Security Controls? <asp:Login>: Provides a standard login capability that allows the users to enter their credentials <asp:LoginName>: Allows you to display the name of the logged-in user <asp:LoginStatus>: Displays whether the user is authenticated or not <asp:LoginView>: Provides various login views depending on the selected template <asp:PasswordRecovery>:  email the users their lost password 36: How do you register JavaScript for webcontrols ? We can register javascript for controls using <CONTROL -name>Attribtues.Add(scriptname,scripttext) method. 37. In which event are the controls fully loaded? Page load event. 38: what is boxing and unboxing? Boxing is assigning a value type to reference type variable. Unboxing is reverse of boxing ie. Assigning reference type variable to value type variable. 39. Differentiate strong typing and weak typing In strong typing, the data types of variable are checked at compile time. On the other hand, in case of weak typing the variable data types are checked at runtime. In case of strong typing, there is no chance of compilation error. Scripts use weak typing and hence issues arises at runtime. 40. How we can force all the validation controls to run? The Page.Validate() method is used to force all the validation controls to run and to perform validation. 41. List all templates of the Repeater control. ItemTemplate AlternatingltemTemplate SeparatorTemplate HeaderTemplate FooterTemplate 42. List the major built-in objects in ASP.NET?  Application Request Response Server Session Context Trace 43. What is the appSettings Section in the web.config file? The appSettings block in web config file sets the user-defined values for the whole application. For example, in the following code snippet, the specified ConnectionString section is used throughout the project for database connection: [csharp] <em><configuration> <appSettings> <add key=”ConnectionString” value=”server=local; pwd=password; database=default” /> </appSettings></em> [/csharp] 44.      Which data type does the RangeValidator control support? The data types supported by the RangeValidator control are Integer, Double, String, Currency, and Date. 45. What is the difference between an HtmlInputCheckBox control and anHtmlInputRadioButton control? In HtmlInputCheckBoxcontrol, multiple item selection is possible whereas in HtmlInputRadioButton controls, we can select only single item from the group of items. 46. Which namespaces are necessary to create a localized application? System.Globalization System.Resources 47. What are the different types of cookies in ASP.NET? Session Cookie – Resides on the client machine for a single session until the user does not log out. Persistent Cookie – Resides on a user’s machine for a period specified for its expiry, such as 10 days, one month, and never. 48. What is the file extension of web service? Web services have file extension .asmx.. 49. What are the components of ADO.NET? The components of ADO.Net are Dataset, Data Reader, Data Adaptor, Command, connection. 50. What is the difference between ExecuteScalar and ExecuteNonQuery? ExecuteScalar returns output value where as ExecuteNonQuery does not return any value but the number of rows affected by the query. ExecuteScalar used for fetching a single value and ExecuteNonQuery used to execute Insert and Update statements.

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• C#/.NET Little Wonders: Interlocked CompareExchange()

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Two posts ago, I discussed the Interlocked Add(), Increment(), and Decrement() methods (here) for adding and subtracting values in a thread-safe, lightweight manner.  Then, last post I talked about the Interlocked Read() and Exchange() methods (here) for safely and efficiently reading and setting 32 or 64 bit values (or references).  This week, we’ll round out the discussion by talking about the Interlocked CompareExchange() method and how it can be put to use to exchange a value if the current value is what you expected it to be. Dirty reads can lead to bad results Many of the uses of Interlocked that we’ve explored so far have centered around either reading, setting, or adding values.  But what happens if you want to do something more complex such as setting a value based on the previous value in some manner? Perhaps you were creating an application that reads a current balance, applies a deposit, and then saves the new modified balance, where of course you’d want that to happen atomically.  If you read the balance, then go to save the new balance and between that time the previous balance has already changed, you’ll have an issue!  Think about it, if we read the current balance as $400, and we are applying a new deposit of $50.75, but meanwhile someone else deposits $200 and sets the total to $600, but then we write a total of $450.75 we’ve lost $200! Now, certainly for int and long values we can use Interlocked.Add() to handles these cases, and it works well for that.  But what if we want to work with doubles, for example?  Let’s say we wanted to add the numbers from 0 to 99,999 in parallel.  We could do this by spawning several parallel tasks to continuously add to a total: 1: double total = 0; 2:  3: Parallel.For(0, 10000, next => 4: { 5: total += next; 6: }); Were this run on one thread using a standard for loop, we’d expect an answer of 4,999,950,000 (the sum of all numbers from 0 to 99,999).  But when we run this in parallel as written above, we’ll likely get something far off.  The result of one of my runs, for example, was 1,281,880,740.  That is way off!  If this were banking software we’d be in big trouble with our clients.  So what happened?  The += operator is not atomic, it will read in the current value, add the result, then store it back into the total.  At any point in all of this another thread could read a “dirty” current total and accidentally “skip” our add.   So, to clean this up, we could use a lock to guarantee concurrency: 1: double total = 0.0; 2: object locker = new object(); 3:  4: Parallel.For(0, count, next => 5: { 6: lock (locker) 7: { 8: total += next; 9: } 10: }); Which will give us the correct result of 4,999,950,000.  One thing to note is that locking can be heavy, especially if the operation being locked over is trivial, or the life of the lock is a high percentage of the work being performed concurrently.  In the case above, the lock consumes pretty much all of the time of each parallel task – and the task being locked on is relatively trivial. Now, let me put in a disclaimer here before we go further: For most uses, lock is more than sufficient for your needs, and is often the simplest solution!    So, if lock is sufficient for most needs, why would we ever consider another solution?  The problem with locking is that it can suspend execution of your thread while it waits for the signal that the lock is free.  Moreover, if the operation being locked over is trivial, the lock can add a very high level of overhead.  This is why things like Interlocked.Increment() perform so well, instead of locking just to perform an increment, we perform the increment with an atomic, lockless method. As with all things performance related, it’s important to profile before jumping to the conclusion that you should optimize everything in your path.  If your profiling shows that locking is causing a high level of waiting in your application, then it’s time to consider lighter alternatives such as Interlocked. CompareExchange() – Exchange existing value if equal some value So let’s look at how we could use CompareExchange() to solve our problem above.  The general syntax of CompareExchange() is: T CompareExchange<T>(ref T location, T newValue, T expectedValue) If the value in location == expectedValue, then newValue is exchanged.  Either way, the value in location (before exchange) is returned. Actually, CompareExchange() is not one method, but a family of overloaded methods that can take int, long, float, double, pointers, or references.  It cannot take other value types (that is, can’t CompareExchange() two DateTime instances directly).  Also keep in mind that the version that takes any reference type (the generic overload) only checks for reference equality, it does not call any overridden Equals(). So how does this help us?  Well, we can grab the current total, and exchange the new value if total hasn’t changed.  This would look like this: 1: // grab the snapshot 2: double current = total; 3:  4: // if the total hasn’t changed since I grabbed the snapshot, then 5: // set it to the new total 6: Interlocked.CompareExchange(ref total, current + next, current); So what the code above says is: if the amount in total (1st arg) is the same as the amount in current (3rd arg), then set total to current + next (2nd arg).  This check and exchange pair is atomic (and thus thread-safe). This works if total is the same as our snapshot in current, but the problem, is what happens if they aren’t the same?  Well, we know that in either case we will get the previous value of total (before the exchange), back as a result.  Thus, we can test this against our snapshot to see if it was the value we expected: 1: // if the value returned is != current, then our snapshot must be out of date 2: // which means we didn't (and shouldn't) apply current + next 3: if (Interlocked.CompareExchange(ref total, current + next, current) != current) 4: { 5: // ooops, total was not equal to our snapshot in current, what should we do??? 6: } So what do we do if we fail?  That’s up to you and the problem you are trying to solve.  It’s possible you would decide to abort the whole transaction, or perhaps do a lightweight spin and try again.  Let’s try that: 1: double current = total; 2:  3: // make first attempt... 4: if (Interlocked.CompareExchange(ref total, current + i, current) != current) 5: { 6: // if we fail, go into a spin wait, spin, and try again until succeed 7: var spinner = new SpinWait(); 8:  9: do 10: { 11: spinner.SpinOnce(); 12: current = total; 13: } 14: while (Interlocked.CompareExchange(ref total, current + i, current) != current); 15: } 16:  This is not trivial code, but it illustrates a possible use of CompareExchange().  What we are doing is first checking to see if we succeed on the first try, and if so great!  If not, we create a SpinWait and then repeat the process of SpinOnce(), grab a fresh snapshot, and repeat until CompareExchnage() succeeds.  You may wonder why not a simple do-while here, and the reason it’s more efficient to only create the SpinWait until we absolutely know we need one, for optimal efficiency. Though not as simple (or maintainable) as a simple lock, this will perform better in many situations.  Comparing an unlocked (and wrong) version, a version using lock, and the Interlocked of the code, we get the following average times for multiple iterations of adding the sum of 100,000 numbers: 1: Unlocked money average time: 2.1 ms 2: Locked money average time: 5.1 ms 3: Interlocked money average time: 3 ms So the Interlocked.CompareExchange(), while heavier to code, came in lighter than the lock, offering a good compromise of safety and performance when we need to reduce contention. CompareExchange() - it’s not just for adding stuff… So that was one simple use of CompareExchange() in the context of adding double values -- which meant we couldn’t have used the simpler Interlocked.Add() -- but it has other uses as well. If you think about it, this really works anytime you want to create something new based on a current value without using a full lock.  For example, you could use it to create a simple lazy instantiation implementation.  In this case, we want to set the lazy instance only if the previous value was null: 1: public static class Lazy<T> where T : class, new() 2: { 3: private static T _instance; 4:  5: public static T Instance 6: { 7: get 8: { 9: // if current is null, we need to create new instance 10: if (_instance == null) 11: { 12: // attempt create, it will only set if previous was null 13: Interlocked.CompareExchange(ref _instance, new T(), (T)null); 14: } 15:  16: return _instance; 17: } 18: } 19: } So, if _instance == null, this will create a new T() and attempt to exchange it with _instance.  If _instance is not null, then it does nothing and we discard the new T() we created. This is a way to create lazy instances of a type where we are more concerned about locking overhead than creating an accidental duplicate which is not used.  In fact, the BCL implementation of Lazy<T> offers a similar thread-safety choice for Publication thread safety, where it will not guarantee only one instance was created, but it will guarantee that all readers get the same instance.  Another possible use would be in concurrent collections.  Let’s say, for example, that you are creating your own brand new super stack that uses a linked list paradigm and is “lock free”.  We could use Interlocked.CompareExchange() to be able to do a lockless Push() which could be more efficient in multi-threaded applications where several threads are pushing and popping on the stack concurrently. Yes, there are already concurrent collections in the BCL (in .NET 4.0 as part of the TPL), but it’s a fun exercise!  So let’s assume we have a node like this: 1: public sealed class Node<T> 2: { 3: // the data for this node 4: public T Data { get; set; } 5:  6: // the link to the next instance 7: internal Node<T> Next { get; set; } 8: } Then, perhaps, our stack’s Push() operation might look something like: 1: public sealed class SuperStack<T> 2: { 3: private volatile T _head; 4:  5: public void Push(T value) 6: { 7: var newNode = new Node<int> { Data = value, Next = _head }; 8:  9: if (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next) 10: { 11: var spinner = new SpinWait(); 12:  13: do 14: { 15: spinner.SpinOnce(); 16: newNode.Next = _head; 17: } 18: while (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next); 19: } 20: } 21:  22: // ... 23: } Notice a similar paradigm here as with adding our doubles before.  What we are doing is creating the new Node with the data to push, and with a Next value being the original node referenced by _head.  This will create our stack behavior (LIFO – Last In, First Out).  Now, we have to set _head to now refer to the newNode, but we must first make sure it hasn’t changed! So we check to see if _head has the same value we saved in our snapshot as newNode.Next, and if so, we set _head to newNode.  This is all done atomically, and the result is _head’s original value, as long as the original value was what we assumed it was with newNode.Next, then we are good and we set it without a lock!  If not, we SpinWait and try again. Once again, this is much lighter than locking in highly parallelized code with lots of contention.  If I compare the method above with a similar class using lock, I get the following results for pushing 100,000 items: 1: Locked SuperStack average time: 6 ms 2: Interlocked SuperStack average time: 4.5 ms So, once again, we can get more efficient than a lock, though there is the cost of added code complexity.  Fortunately for you, most of the concurrent collection you’d ever need are already created for you in the System.Collections.Concurrent (here) namespace – for more information, see my Little Wonders – The Concurent Collections Part 1 (here), Part 2 (here), and Part 3 (here). Summary We’ve seen before how the Interlocked class can be used to safely and efficiently add, increment, decrement, read, and exchange values in a multi-threaded environment.  In addition to these, Interlocked CompareExchange() can be used to perform more complex logic without the need of a lock when lock contention is a concern. The added efficiency, though, comes at the cost of more complex code.  As such, the standard lock is often sufficient for most thread-safety needs.  But if profiling indicates you spend a lot of time waiting for locks, or if you just need a lock for something simple such as an increment, decrement, read, exchange, etc., then consider using the Interlocked class’s methods to reduce wait. Technorati Tags: C#,CSharp,.NET,Little Wonders,Interlocked,CompareExchange,threading,concurrency

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• .NET Code Evolution

  - by Alois Kraus

  Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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• The remote server returned an unexpected response: (400) Bad Request while streaming

  - by phenevo

  Hi, I have problem with streaming. When I send small file like 1kb txt everything is ok, but when I send larger file like 100 kb jpg or 2gb psd I get: The remote server returned an unexpected response: (400) Bad Request. I'm using windows 7, VS 2010 and .net 3.5 and WCF Service library I lost all my weekend on this and I still see this error :/ Please help me Client: var client = new WpfApplication1.ServiceReference1.Service1Client("WSHttpBinding_IService1"); client.GetString("test"); string filename = @"d:\test.jpg"; FileStream fs = new FileStream(filename, FileMode.Open); try { client.ProcessStreamFromClient(fs); } catch (Exception exception) { Console.WriteLine(exception); } app.config: <?xml version="1.0" encoding="utf-8" ?> <configuration> <system.serviceModel> <bindings> <basicHttpBinding> <binding name="StreamedHttp" closeTimeout="10:01:00" openTimeout="10:01:00" receiveTimeout="10:10:00" sendTimeout="10:01:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferSize="65536000" maxBufferPoolSize="524288000" maxReceivedMessageSize="65536000" messageEncoding="Text" textEncoding="utf-8" transferMode="Streamed" useDefaultWebProxy="true"> <readerQuotas maxDepth="0" maxStringContentLength="0" maxArrayLength="0" maxBytesPerRead="0" maxNameTableCharCount="0" /> <security mode="None"> <transport clientCredentialType="None" proxyCredentialType="None" realm="" /> <message clientCredentialType="UserName" algorithmSuite="Default" /> </security> </binding> </basicHttpBinding> </bindings> <client> <endpoint address="http://localhost:8732/Design_Time_Addresses/WcfServiceLibrary2/Service1/" binding="basicHttpBinding" bindingConfiguration="StreamedHttp" contract="ServiceReference1.IService1" name="WSHttpBinding_IService1" /> </client> </system.serviceModel> </configuration> And Wcf ServiceLibrary: public void ProcessStreamFromClient(Stream str) { using (var outStream = new FileStream(@"e:\test.jpg", FileMode.Create)) { var buffer = new byte[4096]; int count; while ((count = str.Read(buffer, 0, buffer.Length)) > 0) { outStream.Write(buffer, 0, count); } } } App.config <?xml version="1.0" encoding="utf-8" ?> <configuration> <system.web> <compilation debug="true" /> </system.web> <!-- When deploying the service library project, the content of the config file must be added to the host's app.config file. System.Configuration does not support config files for libraries. --> <system.serviceModel> <bindings> <basicHttpBinding> <binding name="Binding1" hostNameComparisonMode="StrongWildcard" maxBufferSize="65536000" transferMode="Streamed" bypassProxyOnLocal="false" closeTimeout="10:01:00" openTimeout="10:01:00" receiveTimeout="10:10:00" sendTimeout="10:01:00" maxBufferPoolSize="524288000" maxReceivedMessageSize="65536000" messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true" allowCookies="false"> <security mode="None" /> </binding> </basicHttpBinding> </bindings> <client /> <services> <service name="WcfServiceLibrary2.Service1"> <host> <baseAddresses> <add baseAddress="http://localhost:8732/Design_Time_Addresses/WcfServiceLibrary2/Service1/" /> </baseAddresses> </host> <!-- Service Endpoints --> <!-- Unless fully qualified, address is relative to base address supplied above --> <endpoint address="" binding="basicHttpBinding" contract="WcfServiceLibrary2.IService1"> <!-- Upon deployment, the following identity element should be removed or replaced to reflect the identity under which the deployed service runs. If removed, WCF will infer an appropriate identity automatically. --> <identity> <dns value="localhost"/> </identity> </endpoint> <!-- Metadata Endpoints --> <!-- The Metadata Exchange endpoint is used by the service to describe itself to clients. --> <!-- This endpoint does not use a secure binding and should be secured or removed before deployment --> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/> </service> </services> <behaviors> <serviceBehaviors> <behavior> <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment --> <serviceMetadata httpGetEnabled="True"/> <!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information --> <dataContractSerializer maxItemsInObjectGraph="2147483647"/> <!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information --> <serviceDebug includeExceptionDetailInFaults="false" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> </configuration>

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• SQL Server 2005: Improving performance for thousands or Insert requests. logout-login time= 120ms.

  - by Rad

  Can somebody shed some lights on how SQL Server 2005 deals with may request issued by a client using ADO.NET 2.0. Below is the shortend output of SQL Trace. I can see that connection pooling is working (I believe there is only one connection being pooled). What is not clear to me is why we have so many sp_reset_connection calls i.e a series of: Audit Login, SQL:BatchStarting, RPC:Starting and Audit Logout for each loop in for loop below. I can see that there is constant switching between tempdb and master database which leads me to conclude that we lost the context when next connection is created by fetching it from the pool based on ConectionString argument. I can see that every 15ms I can get 100-200 login/logout per second (reported at the same time by Profiler). The after 15ms I have again a series fo 100-200 login/logout per second. I need clarification on how this might affect much complex insert queries in production environment. I use Enterprise Library 2006, the code is compiled with VS 2005 and it is a console application that parses a flat file with 10 of thousand of rows grouping parent-child rows, runs on an application server and runs 2 stored procedure on a remote SQL Server 2005 inserting a parent record, retrieves Identity value and using it calls the second stored procedure 1, 2 or multiple times (sometimes several thousands) inserting child records. The child table has close to 10 million records with 5-10 indexes some of them being covering non-clustered. There is a pretty complex Insert trigger that copies inserted detail record to an archive table. All in all I only have 7 inserts per second which means it can take 2-4 hours for 50 thousand records. When I run Profiler on the test server (that is almost equivalent with production server) I can see that there is about 120ms between Audit Logout and Audit Login trace entries which almost give me chance to insert about 8 records. So my question is if there is some way to improve inserting of records since the company loads 100 thousands of records and does daily planning and has SLA to fulfill client request coming as flat file orders and some big files 10 thousands have to be processed(imported quickly). 4 hours to import 60 thousands should be reduced to 30 minutes. I was thinking to use BatchSize of DataAdapter to send multiple stored procedure calls, SQL Bulk inserts to batch multiple inserts from DataReader or DataTable, SSIS fast load. But I don't know how to properly analyze re-indexing and stats population and maybe this has to take some time to finish. What is worse is that the company uses the biggest table for reporting and other online processing and indexes cannot be dropped. I manage transaction manually by setting a field to a value and do an transactional update changing that value to a new value that other applications are using to get committed rows. Please advise how to approach this problem. For now I am trying to have a staging tables with minimal logging in a separate database and no indexes and I will try to do batched (massive) parent child inserts. I believe Production DB has simple recovery model, but it could be full recovery. If DB user that is being used by my .NET console application has bulkadmin role does it mean its bulk inserts are minimally logged. I understand that when a table has clustered and many non-clustered indexes that inserts are still logged for each row. Connection pooling is working, but with many login/logouts. Why? for (int i = 1; i <= 10000; i++){ using (SqlConnection conn = new SqlConnection("server=(local);database=master;integrated security=sspi;")) {conn.Open(); using (SqlCommand cmd = conn.CreateCommand()){ cmd.CommandText = "use tempdb"; cmd.ExecuteNonQuery();}}} SQL Server Profiler trace: Audit Login master 2010-01-13 23:18:45.337 1 - Nonpooled SQL:BatchStarting use tempdb master 2010-01-13 23:18:45.337 RPC:Starting exec sp_reset_conn tempdb 2010-01-13 23:18:45.337 Audit Logout tempdb 2010-01-13 23:18:45.337 2 - Pooled Audit Login -- network protocol master 2010-01-13 23:18:45.383 2 - Pooled SQL:BatchStarting use tempdb master 2010-01-13 23:18:45.383 RPC:Starting exec sp_reset_conn tempdb 2010-01-13 23:18:45.383 Audit Logout tempdb 2010-01-13 23:18:45.383 2 - Pooled Audit Login -- network protocol master 2010-01-13 23:18:45.383 2 - Pooled SQL:BatchStarting use tempdb master 2010-01-13 23:18:45.383 RPC:Starting exec sp_reset_conn tempdb 2010-01-13 23:18:45.383 Audit Logout tempdb 2010-01-13 23:18:45.383 2 - Pooled

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• How to export SSIS to Microsoft Excel without additional software?

  - by Dr. Zim

  This question is long winded because I have been updating the question over a very long time trying to get SSIS to properly export Excel data. I managed to solve this issue, although not correctly. Aside from someone providing a correct answer, the solution listed in this question is not terrible. The only answer I found was to create a single row named range wide enough for my columns. In the named range put sample data and hide it. SSIS appends the data and reads metadata from the single row (that is close enough for it to drop stuff in it). The data takes the format of the hidden single row. This allows headers, etc. WOW what a pain in the butt. It will take over 450 days of exports to recover the time lost. However, I still love SSIS and will continue to use it because it is still way better than Filemaker LOL. My next attempt will be doing the same thing in the report server. Original question notes: If you are in Sql Server Integrations Services designer and want to export data to an Excel file starting on something other than the first line, lets say the forth line, how do you specify this? I tried going in to the Excel Destination of the Data Flow, changed the AccessMode to OpenRowSet from Variable, then set the variable to "YPlatters$A4:I20000" This fails saying it cannot find the sheet. The sheet is called YPlatters. I thought you could specify (Sheet$)(Starting Cell):(Ending Cell)? Update Apparently in Excel you can select a set of cells and name them with the name box. This allows you to select the name instead of the sheet without the $ dollar sign. Oddly enough, whatever the range you specify, it appends the data to the next row after the range. Oddly, as you add data, it increases the named selection's row count. Another odd thing is the data takes the format of the last line of the range specified. My header rows are bold. If I specify a range that ends with the header row, the data appends to the row below, and makes all the entries bold. if you specify one row lower, it puts a blank line between the header row and the data, but the data is not bold. Another update No matter what I try, SSIS samples the "first row" of the file and sets the metadata according to what it finds. However, if you have sample data that has a value of zero but is formatted as the first row, it treats that column as text and inserts numeric values with a single quote in front ('123.34). I also tried headers that do not reflect the data types of the columns. I tried changing the metadata of the Excel destination, but it always changes it back when I run the project, then fails saying it will truncate data. If I tell it to ignore errors, it imports everything except that column. Several days of several hours a piece later... Another update I tried every combination. A mostly working example is to create the named range starting with the column headers. Format your column headers as you want the data to look as the data takes on this format. In my example, these exist from A4 to E4, which is my defined range. SSIS appends to the row after the defined range, so defining A4 to E68 appends the rows starting at A69. You define the Connection as having the first row contains the field names. It takes on the metadata of the header row, oddly, not the second row, and it guesses at the data type, not the formatted data type of the column, i.e., headers are text, so all my metadata is text. If your headers are bold, so is all of your data. I even tried making a sample data row without success... I don't think anyone actually uses Excel with the default MS SSIS export. If you could define the "insert range" (A5 to E5) with no header row and format those columns (currency, not bold, etc.) without it skipping a row in Excel, this would be very helpful. From what I gather, noone uses SSIS to export Excel without a third party connection manager. Any ideas on how to set this up properly so that data is formatted correctly, i.e., the metadata read from Excel is proper to the real data, and formatting inherits from the first row of data, not the headers in Excel? One last update (July 17, 2009) I got this to work very well. One thing I added to Excel was the IMEX=1 in the Excel connection string: "Excel 8.0;HDR=Yes;IMEX=1". This forces Excel (I think) to look at all rows to see what kind of data is in it. Generally, this does not drop information, say for instance if you have a zip code then about 9 rows down you have a zip+4, Excel without this blanks that field entirely without error. With IMEX=1, it recognizes that Zip is actually a character field instead of numeric. And of course, one more update (August 27, 2009) The IMEX=1 will succeed importing data with missing contents in the first 8 rows, but it will fail exporting data where no data exists. So, have it on your import connection string, but not your export Excel connection string. I have to say, after so much fiddling, it works pretty well.

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• Iterate through deserialized xml object

  - by Bruce Adams

  I have a deserialized xml c# objet. I need to iterate through the oject to display all items, in this case there's just one, and display the name, colors and sizes for each item. The xml: <?xml version="1.0" encoding="utf-8"?> <Catalog Name="Example"> <Items> <Item Name="ExampleItem"> <Colors> <Color Name="Black" Value="#000" /> <Color Name="White" Value="#FFF" /> </Colors> <Sizes> <Size Name="Small" Value="10" /> <Size Name="Medium" Value="20" /> </Sizes> </Item> </Items> </Catalog> xsd.exe generated classes: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:2.0.50727.4927 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ using System.Xml.Serialization; // // This source code was auto-generated by xsd, Version=2.0.50727.42. // /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] [System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)] public partial class Catalog { private CatalogItemsItem[][] itemsField; private string nameField; /// <remarks/> [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified)] [System.Xml.Serialization.XmlArrayItemAttribute("Item", typeof(CatalogItemsItem[]), Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)] public CatalogItemsItem[][] Items { get { return this.itemsField; } set { this.itemsField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] public partial class CatalogItemsItem { private CatalogItemsItemColorsColor[][] colorsField; private CatalogItemsItemSizesSize[][] sizesField; private string nameField; /// <remarks/> [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified)] [System.Xml.Serialization.XmlArrayItemAttribute("Color", typeof(CatalogItemsItemColorsColor[]), Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)] public CatalogItemsItemColorsColor[][] Colors { get { return this.colorsField; } set { this.colorsField = value; } } /// <remarks/> [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified)] [System.Xml.Serialization.XmlArrayItemAttribute("Size", typeof(CatalogItemsItemSizesSize[]), Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)] public CatalogItemsItemSizesSize[][] Sizes { get { return this.sizesField; } set { this.sizesField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] public partial class CatalogItemsItemColorsColor { private string nameField; private string valueField; /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Value { get { return this.valueField; } set { this.valueField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] public partial class CatalogItemsItemSizesSize { private string nameField; private string valueField; /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Value { get { return this.valueField; } set { this.valueField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] [System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)] public partial class NewDataSet { private Catalog[] itemsField; /// <remarks/> [System.Xml.Serialization.XmlElementAttribute("Catalog")] public Catalog[] Items { get { return this.itemsField; } set { this.itemsField = value; } } } Deserialization code: System.Xml.Serialization.XmlSerializer xSerializer = new System.Xml.Serialization.XmlSerializer(typeof(Catalog)); TextReader reader = new StreamReader("catalog.xml"); Catalog catalog = (Catalog)xSerializer.Deserialize(reader); foreach (var item in catalog.Items) { } reader.Close(); When I setp through the code there is one item present in catalog.items, but it is empty, no name, colors or sizes. Any ideas what I need to do? Thanks

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• What is the best Battleship AI?

  - by John Gietzen

  Battleship! Back in 2003, (when I was 17,) I competed in a Battleship AI coding competition. Even though I lost that tournament, I had a lot of fun and learned a lot from it. Now, I would like to resurrect this competition, in the search of the best battleship AI. Here is the framework: Battleship.zip The winner will be awarded +450 reputation! The competition will be held starting on the 17th of November, 2009. No entries or edits later than zero-hour on the 17th will be accepted. (Central Standard Time) Submit your entries early, so you don't miss your opportunity! To keep this OBJECTIVE, please follow the spirit of the competition. Rules of the game: The game is be played on a 10x10 grid. Each competitor will place each of 5 ships (of lengths 2, 3, 3, 4, 5) on their grid. No ships may overlap, but they may be adjacent. The competitors then take turns firing single shots at their opponent. A variation on the game allows firing multiple shots per volley, one for each surviving ship. The opponent will notify the competitor if the shot sinks, hits, or misses. Game play ends when all of the ships of any one player are sunk. Rules of the competition: The spirit of the competition is to find the best Battleship algorithm. Anything that is deemed against the spirit of the competition will be grounds for disqualification. Interfering with an opponent is against the spirit of the competition. Multithreading may be used under the following restrictions: No more than one thread may be running while it is not your turn. (Though, any number of threads may be in a "Suspended" state). No thread may run at a priority other than "Normal". Given the above two restrictions, you will be guaranteed at least 3 dedicated CPU cores during your turn. A limit of 1 second of CPU time per game is allotted to each competitor on the primary thread. Running out of time results in losing the current game. Any unhandled exception will result in losing the current game. Network access and disk access is allowed, but you may find the time restrictions fairly prohibitive. However, a few set-up and tear-down methods have been added to alleviate the time strain. Code should be posted on stack overflow as an answer, or, if too large, linked. Max total size (un-compressed) of an entry is 1 MB. Officially, .Net 2.0 / 3.5 is the only framework requirement. Your entry must implement the IBattleshipOpponent interface. Scoring: Best 51 games out of 101 games is the winner of a match. All competitors will play matched against each other, round-robin style. The best half of the competitors will then play a double-elimination tournament to determine the winner. (Smallest power of two that is greater than or equal to half, actually.) I will be using the TournamentApi framework for the tournament. The results will be posted here. If you submit more than one entry, only your best-scoring entry is eligible for the double-elim. Good luck! Have fun! EDIT 1: Thanks to Freed, who has found an error in the Ship.IsValid function. It has been fixed. Please download the updated version of the framework. EDIT 2: Since there has been significant interest in persisting stats to disk and such, I have added a few non-timed set-up and tear-down events that should provide the required functionality. This is a semi-breaking change. That is to say: the interface has been modified to add functions, but no body is required for them. Please download the updated version of the framework. EDIT 3: Bug Fix 1: GameWon and GameLost were only getting called in the case of a time out. Bug Fix 2: If an engine was timing out every game, the competition would never end. Please download the updated version of the framework. EDIT 4: Results!

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• Binding collection indexes to a WPF DataGrid at runtime

  - by bearda

  After trying to develop our own control to display a table of data we stumbled on the WPF toolkit DataGrid and thought we were saved. A couple hours later I'm scratching my head trying to figure out if it can do what we really want it to do. The DataGrid seems to be based on displaying various properties of a single object, where I think I need something that can display a collection's items, I want to display a table of strings with a variable number of rows and a variable number of columns. Each row represents the state of a number of inputs at a given time. The number of samples may change, and the number of inputs may change at runtime. As a result, I can't create a custom object that represents a row with a property for each input. This makes the DataGrid binding more complicated, since I can't bind to a fixed property for each column. I thought I found a workaround for this by binding to ".[" + channelIndex + ]" but it hasn't worked out quite the way I wanted. Right now I have a collection of a collection of strings that represents the two-dimensional array of strings. I'm using ObservableCollection so string change event notifications work, but I can use any collection type needed. It looked like everything was working great until I realized that every row was showing the same line of data. Binding in C# is not my strong suit, so I'm kind of lost on what's going wrong. Is what I'm trying to do overall even possible with the WPF Toolkit DataGrid? using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; using Microsoft.Windows.Controls; using System.ComponentModel; using System.Collections; using System.Collections.ObjectModel; namespace WRE.NGDAS.UILayer { /// <summary> /// Interaction logic for DataTableControl.xaml /// </summary> public partial class DataTableControl : UserControl { #region Constants private const int lineHeight = 25; #endregion #region Type Definitions private class TableChannelInfo { internal string ChannelName = string.Empty; internal int Column = 0; public override string ToString() { return ChannelName; } } internal class NotifyString : INotifyPropertyChanged { private string text = String.Empty; public event PropertyChangedEventHandler PropertyChanged; public string Text { get { return text; } set { text = value; NotifyPropertyChanged( "Text" ); } } public NotifyString(string newText) { text = newText; } protected void NotifyPropertyChanged( string propertyChanged ) { if ( PropertyChanged != null ) { PropertyChanged(this, new PropertyChangedEventArgs(propertyChanged)); } } } #endregion #region Private Data Members string[] channels = null; int numberFixed = 0; int numberOfRows = 0; ObservableCollection<ObservableCollection<NotifyString>> tableText = null; #endregion public DataTableControl( List<string> channelNames, List<string> nameToolTips, int numberFixedColumns, int numberRows ) { InitializeComponent(); numberFixed = numberFixedColumns; numberOfRows = numberRows; tableText = new ObservableCollection<ObservableCollection<NotifyString>>(); dataGrid.ItemsSource = tableText; channels = new string[channelNames.Count]; for (int channelIndex = 0; channelIndex < channelNames.Count; channelIndex++) { channels[channelIndex] = channelNames[channelIndex]; tableText.Add(new ObservableCollection<NotifyString>()); for (int i = 0; i < numberOfRows; i++) { tableText[channelIndex].Add( new NotifyString(String.Empty) ); } Binding textBinding = new Binding( ".[" + channelIndex + "]" ); textBinding.Mode = BindingMode.OneWay; textBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged; textBinding.Source = tableText[channelIndex]; DataGridTextColumn newColumn = new DataGridTextColumn(); newColumn.Header = channelNames[channelIndex]; newColumn.DisplayIndex = channelIndex; newColumn.Binding = textBinding; if ( channelIndex < numberFixed ) { newColumn.CanUserReorder = false; } dataGrid.Columns.Add(newColumn); } //Height = lineHeight + numberOfRows * lineHeight; } internal void UpdateChannelRow( int rowNumber, List<string> channelValues, DisplayColors color ) { if ( rowNumber < numberOfRows ) { for (int column = 0; column < channelValues.Count; column++) { if ( column < channels.GetLength(0) ) { tableText[column][rowNumber].Text = channelValues[column]; } } } } } }

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• starting with flex - please let me know if the direction is right (ActionScript vs MXML separation)

  - by Piotr

  Hi, I've just started learning flex using OReilly "Programming Flex 3.0". After completing three chapters and starting fourth (ActionScript), and not having enough patience to wait till completing chapter 22 I started to practice :) One bit that I have most worries about right now is the the dual coding mode (MXML vs ActionScript) Please have a look at my code below (it compiles via mxmlc design.mxml, second file 'code.as' should be in same directory) and advise if the separation I used between visual design and code is appropriate. Also - if some smart guy could show me how to recode same example with *.as being a class file [package?] it would be highly appreciated. I got lost with creating directory structure for package - and did not find it most intuitive, especially for small project that has two files like my example. Code: design.mxml <?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Script source="code.as"/> <mx:VBox> <mx:TextInput creationComplete="initializeCalculator()" id="txtScreen"/> <mx:HBox> <mx:Button click="click('7')" id="btn7" label="7"/> <mx:Button click="click('8')" id="btn8" label="8"/> <mx:Button click="click('9')" id="btn9" label="9"/> <mx:Button click="click('C')" id="btnClear" label="C"/> </mx:HBox> <mx:HBox> <mx:Button click="click('4')" id="btn4" label="4"/> <mx:Button click="click('5')" id="btn5" label="5"/> <mx:Button click="click('6')" id="btn6" label="6"/> <mx:Button click="click('/')" id="btnDivide" label="/"/> </mx:HBox> <mx:HBox> <mx:Button click="click('1')" id="btn1" label="1"/> <mx:Button click="click('2')" id="btn2" label="2"/> <mx:Button click="click('3')" id="btn3" label="3"/> <mx:Button click="click('*')" id="btnMultiply" label="*"/> </mx:HBox> <mx:HBox> <mx:Button click="click('0')" id="btn0" label="0"/> <mx:Button click="click('=')" id="btnEqual" label="="/> <mx:Button click="click('-')" id="btnMinus" label="-"/> <mx:Button click="click('+')" id="btnPlus" label="+"/> </mx:HBox> </mx:VBox> </mx:Application> code: code.as public var res:int = 0; public var previousOperator:String = ""; public var previousRes:int=0; public function initializeCalculator():void{ txtScreen.text = res.toString(); } public function click(code:String):void{ if (code=="1" || code=="2" || code=="3" || code=="4" || code=="5" || code=="6" || code=="7" || code=="8" || code=="9" || code=="0"){ res = res*10 + int(code); txtScreen.text = res.toString(); } else if (code=="C"){ res = 0; previousOperator =""; previousRes = 0; txtScreen.text = res.toString(); } else{ calculate(code); } } public function calculate(operator:String):void{ var tmpRes:int; if (previousOperator=="+"){ tmpRes = previousRes + res; } else if (previousOperator=="-"){ tmpRes = previousRes - res; } else if (previousOperator=="/"){ tmpRes = previousRes / res; } else if (previousOperator=="*"){ tmpRes = previousRes * res; } else{ tmpRes = res; } previousOperator = operator; previousRes = tmpRes; txtScreen.text = previousRes.toString(); res = 0; if (previousOperator=="=") { res = tmpRes; txtScreen.text=res.toString(); } } PS. If you have comments that this calculator does not calculate properly, they are also appreciated, yet most important are comments on best practices in Flex.

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• Facebook Connect login button not rendering

  - by tloflin

  I'm trying to implement a Facebook Connect Single Sign-on site. I originally just had a Connect button (<fb:login-button>), which the user had to click every time they wanted to sign in. I now have the auto login and logout features working. That is, my site will detect a logged-in Facebook account and automatically authenticate them if it can find a match to one of my site's user accounts, and automatically deauthenticate if the Facebook session is lost. I also have a manual logout button that will log the user out of both my site and Facebook. All of those are working correctly, but now my original Connect button is intermittently not being rendered correctly. It just shows up as the plain XHTML (ie., it looks like plain text--not a button--and is unclickable), and no XFBML is applied. Here is the basic code: On every page: <body> {...} <script src="http://static.ak.connect.facebook.com/js/api_lib/v0.4/FeatureLoader.js.php" type="text/javascript"></script> <script type="text/javascript> FB.init('APIKey', '/xd_receiver.htm'); var isAuth; // isAuth determines if the user is authenticated on my site // it should be true on the logout page, false on the login page FB.ensureInit(function(){ var session = FB.Facebook.apiClient.get_session(); if (session && !isAuth) { PageMethods.FacebookLogin(session.uid, session.session_key, FBLogin, FBLoginFail); // This is an AJAX call that authenticates the user on my site. } else if(!session && isFBAuth) { PageMethods.FacebookLogout(FBLogout, FBLogoutFail); // This is an AJAX call that deauthenticates the user on my site. } // the callback functions do nothing at the moment }); </script> {...} </body> On the login page: (this page is not visible to logged in users) <body> {...} <script src="http://static.ak.connect.facebook.com/js/api_lib/v0.4/FeatureLoader.js.php" type="text/javascript"></script> <script type="text/javascript> FB.init('APIKey', '/xd_receiver.htm'); {...} // auto-auth code as on every page </script> <!-- This is the button that fails to render --> <fb:login-button v="2" onlogin="UserSignedIntoFB();" size="large" autologoutlink="true"><fb:intl>Login With Your Facebook Account</fb:intl></fb:login-button> <script type="text/javascript"> function UserSignedIntoFB() { {...} // posts back to the server which authenticates the user on my site & redirects } </script> {...} </body> On the logout page: (this page is not visible to logged out users) <body> {...} <script src="http://static.ak.connect.facebook.com/js/api_lib/v0.4/FeatureLoader.js.php" type="text/javascript"></script> <script type="text/javascript> FB.init('APIKey', '/xd_receiver.htm'); {...} // auto-auth code as on every page </script> <script type="text/javascript"> function FBLoggedOut() { {...} // posts back to the server which deauthenticates the user on my site & redirects to login } function Logout() { if (FB.Facebook.apiClient.get_session()) { FB.Connect.logout(FBLoggedOut); // logs out of Facebook if it's a Facebook account return false; } else { return true; // posts back if it's a non-Facebook account & redirects to login } } </script> <a onclick="return Logout();" href="postback_url">Sign Out</a> {...} </body> Some things I've already looked at: The automatic login and logout are working great. I can log in and out of Facebook on another tab and my site will notice the session changes and update accordingly. The logout seems to be working fine: when clicked, it deauthenticates the user and logs them out of Facebook, as intended. The issue seems to usually happen after a Facebook user is logged out, but it happens somewhat intermittently; it might happen before they ever login, and it goes away after a few minutes/refreshes. Some cookies are left over after the login/logout process, but deleting them does not fix the issue. Restarting the browser does not fix the issue. The user is definitely logged out of Facebook and my site when the problem occurs. I've checked for Facebook sessions and site authentication. All external script calls are being served up correctly. I have a suspicion that there's something else I need to be doing upon logout (like clearing session or cookies), but according to everything I've read about Facebook Connect, all I need to do is call the logout function (and deauthenticate on my server-side). I'm really at a loss; does anybody have any ideas what could be wrong?

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• SOLVED mwfeedparser integrating in my app gives EXC_BAD_ACCESS (code=1, address=0xa0040008)

  - by Pranoy C

  SOLVED- Got it! The problem was that since I am creating the DoParsingStuff *parseThisUrl object in the viewDidLoad method, it's scope was only within that method. So after the method finished, the object got deallocated. I changed it to an instance variable instead and now it works. It gives a different error but that it an entirely different issue. Issue was: I have been struggling with trying to integrate the mwfeedparser library in my app for parsing RSS and ATOM feeds. It throws a gives EXC_BAD_ACCESS error which I can't seem to troubleshoot. //My Class looks like - My interface looks like: #import <Foundation/Foundation.h> #import "MWFeedParser.h" #import "NSString+HTML.h" @protocol ParseCompleted <NSObject> -(void)parsedArray:(NSMutableArray *)parsedArray; @end @interface DoParsingStuff : NSObject<MWFeedParserDelegate> @property (nonatomic,strong) NSMutableArray *parsedItems; @property (nonatomic, strong) NSArray *itemsToDisplay; @property (nonatomic,strong) MWFeedParser *feedParser; @property (nonatomic,strong) NSURL *feedurl; @property (nonatomic,strong) id <ParseCompleted> delegate; -(id)initWithFeedURL:(NSURL *)url; @end //And Implementaion: #import "DoParsingStuff.h" @implementation DoParsingStuff @synthesize parsedItems = _parsedItems; @synthesize itemsToDisplay = _itemsToDisplay; @synthesize feedParser = _feedParser; @synthesize feedurl=_feedurl; @synthesize delegate = _delegate; -(id)initWithFeedURL:(NSURL *)url{ if(self = [super init]){ _feedurl=url; _feedParser = [[MWFeedParser alloc] initWithFeedURL:_feedurl]; _feedParser.delegate=self; _feedParser.feedParseType=ParseTypeFull; _feedParser.connectionType=ConnectionTypeAsynchronously; } return self; } -(void)doParsing{ BOOL y = [_feedParser parse]; } # pragma mark - # pragma mark MWFeedParserDelegate - (void)feedParserDidStart:(MWFeedParser *)parser { //Just tells what url is being parsed e.g. http://www.wired.com/reviews/feeds/latestProductsRss NSLog(@"Started Parsing: %@", parser.url); } - (void)feedParser:(MWFeedParser *)parser didParseFeedInfo:(MWFeedInfo *)info { //What is the Feed about e.g. "Product Reviews" NSLog(@"Parsed Feed Info: “%@”", info.title); //self.title = info.title; } - (void)feedParser:(MWFeedParser *)parser didParseFeedItem:(MWFeedItem *)item { //Prints current element's title e.g. “An Arthropod for Your iDevices” NSLog(@"Parsed Feed Item: “%@”", item.title); if (item) [_parsedItems addObject:item]; } - (void)feedParserDidFinish:(MWFeedParser *)parser {//This is where you can do your own stuff with the parsed items NSLog(@"Finished Parsing%@", (parser.stopped ? @" (Stopped)" : @"")); [_delegate parsedArray:_parsedItems]; //[self updateTableWithParsedItems]; } - (void)feedParser:(MWFeedParser *)parser didFailWithError:(NSError *)error { NSLog(@"Finished Parsing With Error: %@", error); if (_parsedItems.count == 0) { //self.title = @"Failed"; // Show failed message in title } else { // Failed but some items parsed, so show and inform of error UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Parsing Incomplete" message:@"There was an error during the parsing of this feed. Not all of the feed items could parsed." delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil]; [alert show]; } //[self updateTableWithParsedItems]; } @end //I am calling this from my main viewcontroller as such: #import "DoParsingStuff.h" @interface ViewController : UIViewController <ParseCompleted> .... //And I have the following methods in my implementation: DoParsingStuff *parseThisUrl = [[DoParsingStuff alloc] initWithFeedURL:[NSURL URLWithString:@"http://www.theverge.com/rss/index.xml"]]; parseThisUrl.delegate=self; [parseThisUrl doParsing]; I have the method defined here as- -(void)parsedArray:(NSMutableArray *)parsedArray{ NSLog(@"%@",parsedArray); } //I stepped through breakpoints- When I try to go through the breakpoints, I see that everything goes fine till the very last [parseThisUrl doParsing]; in my delegate class. After that it starts showing me memory registers where I get lost. I think it could be due to arc as I have disabled arc on the mwfeedparser files but am using arc in the above classes. If you need the entire project for this, let me know. I tried it with NSZombies enabled and got a bit more info out of it: -[DoParsingStuff respondsToSelector:]: message sent to deallocated instance 0x6a52480 I am not using release/autorelease/retain etc. in this class...but it is being used in the mwfeedparser library.

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• How to display and update data in MVC2

  - by Picflight

  Table Product Product Id Product Name Table ProductSupplier ProductSupplierId ProductId SupplierId Table Supplier SupplierId SupplierName I have the above 3 tables in my database, ProductSupplier is the lookup table. Each Product can have many suppliers. I am using Entity Framework. Using Web Forms it was fairly easy to display a Product on a web page and bind a repeater with the suppliers information. Also, with Web Forms it was easy to Add new Product and suppliers, the linkage seemed easy. How do you do this sort of functionality in MVC? In the Create View below, I want to be able to Add the Supplier as well. Is there a better approach that I might be missing here? This is how I did it with Web Forms. Beyond the code below I am totally lost. I can show data in a list and also display the Suppliers for each Product, but how do I Add and Edit. Should I break it into different views? With Web Forms I could do it all in one page. namespace MyProject.Mvc.Models { [MetadataType(typeof(ProductMetaData))] public partial class Product { public Product() { // Initialize Product this.CreateDate = System.DateTime.Now; } } public class ProductMetaData { [Required(ErrorMessage = "Product name is required")] [StringLength(50, ErrorMessage = "Product name must be under 50 characters")] public object ProductName { get; set; } [Required(ErrorMessage = "Description is required")] public object Description { get; set; } } public class ProductFormViewModel { public Product Product { get; private set; } public IEnumerable<ProductSupplier> ProductSupplier { get; private set; } public ProductFormViewModel() { Product = new Product(); } public ProductFormViewModel(Product product) { Product = product; ProductSupplier = product.ProductSupplier; } } } ProductRepository public Product GetProduct(int id) { var p = db.Product.FirstOrDefault(por => por.ProductId == id); p.ProductSupplier.Attach(p.ProductSupplier.CreateSourceQuery().Include("Product").ToList()); return p; } Product Create View <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MyProject.Mvc.Models.ProductFormViewModel>" %> <%= Html.ValidationSummary("Please correct the errors and try again.") %> <% using (Html.BeginForm()) {%> <fieldset> <legend>Fields</legend> <div class="editor-label"> <%= Html.LabelFor(model => model.Product.ProductId) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Product.ProductId) %> <%= Html.ValidationMessageFor(model => model.Product.ProductId) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Product.ProductName) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Product.ProductName) %> <%= Html.ValidationMessageFor(model => model.Product.ProductName) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Product.Description) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Product.Description) %> <%= Html.ValidationMessageFor(model => model.Product.Description) %> </div> <p> <input type="submit" value="Create" /> </p> </fieldset> <% } %>

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• EXC_BAD_INSTRUCTION (SIGILL) at random during use of app. Bug in AppKit?

  - by Ger Teunis

  I'm currently testing a new version of an app of mine on OSX 10.5 An user reported some weird crashes during use of the application, sadly not reproducible by me. At first sight it seems to happen randomly, once he had the crash while opening an NSOpenPanel and once during focusing an NSTextField and once during NSView switch in a parent view. If you have any idea which area I should look at it would be greatly appreciated! I'm completely lost here. App is compiled in XCode 3.2.1 with SDK 10.5 and targetted at 10.5 He send me these crashes: Crash 1 Process: NZBVortex [43622] Path: /Users/cero/Downloads/NZBVortex.app/Contents/MacOS/NZBVortex Identifier: com.NZBVortex.NZBVortex Version: 0.5.5 (0.5.5) Code Type: X86-64 (Native) Parent Process: launchd [97] Interval Since Last Report: 1951 sec Crashes Since Last Report: 1 Per-App Interval Since Last Report: 1858 sec Per-App Crashes Since Last Report: 1 Date/Time: 2010-03-23 23:43:49.671 +0100 OS Version: Mac OS X 10.5.8 (9L31a) Report Version: 6 Anonymous UUID: 98AB0386-590B-4E0D-B7AC-3F7AA4E7238E Exception Type: EXC_BAD_INSTRUCTION (SIGILL) Exception Codes: 0x0000000000000001, 0x0000000000000000 Crashed Thread: 0 Application Specific Information: objc[43622]: alt handlers in objc runtime are buggy! - Hide quoted text - Thread 0 Crashed: 0 libobjc.A.dylib 0x00007fff82baef6e _objc_fatal + 238 1 libobjc.A.dylib 0x00007fff82bb2ea4 objc_addExceptionHandler + 302 2 com.apple.CoreFoundation 0x00007fff842b1090 _CFDoExceptionOperation + 528 3 com.apple.AppKit 0x00007fff81f75e26 _NSAppKitLock + 81 4 com.apple.AppKit 0x00007fff81f80f8f -[NSView nextKeyView] + 56 5 com.apple.AppKit 0x00007fff81f81018 -[NSView _primitiveSetNextKeyView:] + 72 6 com.apple.AppKit 0x00007fff820732b1 -[NSView _recursiveSetDefaultKeyViewLoop] + 242 7 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 8 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 9 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 10 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 11 com.apple.AppKit 0x00007fff82072fc3 -[NSView _setDefaultKeyViewLoop] + 279 12 com.apple.AppKit 0x00007fff82072e70 -[NSWindow recalculateKeyViewLoop] + 36 13 com.apple.AppKit 0x00007fff821dd149 -[NSSavePanel(NSSavePanelRuntime) _loadPreviousModeAndLayout] + 39 14 com.apple.AppKit 0x00007fff821dcf9e -[NSSavePanel(NSSavePanelRuntime) runModalForDirectory:file:types:] + 71 15 com.NZBVortex.NZBVortex 0x000000010000b7ee -[MainWindowViewController openNZBFileButtonClick:] + 62 16 com.apple.AppKit 0x00007fff821c96bf -[NSToolbarButton sendAction:to:] + 77 17 com.apple.AppKit 0x00007fff821c8bb7 -[NSToolbarItemViewer mouseDown:] + 5362 18 com.apple.AppKit 0x00007fff82082783 -[NSWindow sendEvent:] + 5068 19 com.apple.AppKit 0x00007fff8204fd46 -[NSApplication sendEvent:] + 5089 20 com.apple.AppKit 0x00007fff81faa562 -[NSApplication run] + 497 21 com.apple.AppKit 0x00007fff81f772f0 NSApplicationMain + 373 22 com.NZBVortex.NZBVortex 0x0000000100012a69 main + 9 23 com.NZBVortex.NZBVortex 0x0000000100001a84 start + 52 Crash 2 Process: NZBVortex [43600] Path: /Users/cero/Downloads/NZBVortex.app/Contents/MacOS/NZBVortex Identifier: com.NZBVortex.NZBVortex Version: 0.5.5 (0.5.5) Code Type: X86-64 (Native) Parent Process: launchd [97] Interval Since Last Report: 727 sec Crashes Since Last Report: 1 Per-App Interval Since Last Report: 616 sec Per-App Crashes Since Last Report: 1 Date/Time: 2010-03-23 23:11:20.000 +0100 OS Version: Mac OS X 10.5.8 (9L31a) Report Version: 6 Anonymous UUID: 98AB0386-590B-4E0D-B7AC-3F7AA4E7238E Exception Type: EXC_BAD_INSTRUCTION (SIGILL) Exception Codes: 0x0000000000000001, 0x0000000000000000 Crashed Thread: 0 Application Specific Information: objc[43600]: alt handlers in objc runtime are buggy! Thread 0 Crashed: 0 libobjc.A.dylib 0x00007fff82baef6e _objc_fatal + 238 1 libobjc.A.dylib 0x00007fff82bb2ea4 objc_addExceptionHandler + 302 2 com.apple.CoreFoundation 0x00007fff842b1090 _CFDoExceptionOperation + 528 3 com.apple.AppKit 0x00007fff81f75e26 _NSAppKitLock + 81 4 com.apple.AppKit 0x00007fff81f80f8f -[NSView nextKeyView] + 56 5 com.apple.AppKit 0x00007fff81f81018 -[NSView _primitiveSetNextKeyView:] + 72 6 com.apple.AppKit 0x00007fff820732b1 -[NSView _recursiveSetDefaultKeyViewLoop] + 242 7 com.apple.AppKit 0x00007fff82156700 -[NSTabView _recursiveSetDefaultKeyViewLoop] + 119 8 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 9 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 10 com.apple.AppKit 0x00007fff82072fc3 -[NSView _setDefaultKeyViewLoop] + 279 11 com.apple.AppKit 0x00007fff82072e70 -[NSWindow recalculateKeyViewLoop] + 36 12 com.NZBVortex.NZBVortex 0x000000010000b527 -[MainWindowViewController showView:sender:] + 1639 13 com.NZBVortex.NZBVortex 0x000000010000ae6b -[MainWindowViewController preferencesSaveAlertDidEnd:returnCode:contextInfo:] + 91 14 com.apple.AppKit 0x00007fff82224291 -[NSAlert didEndAlert:returnCode:contextInfo:] + 107 15 com.apple.AppKit 0x00007fff82224197 -[NSAlert buttonPressed:] + 279 16 com.apple.AppKit 0x00007fff82085d46 -[NSApplication sendAction:to:from:] + 97 17 com.apple.AppKit 0x00007fff82085c7f -[NSControl sendAction:to:] + 97 18 com.apple.AppKit 0x00007fff820851b0 -[NSCell trackMouse:inRect:ofView:untilMouseUp:] + 1841 19 com.apple.AppKit 0x00007fff820849d6 -[NSButtonCell trackMouse:inRect:ofView:untilMouseUp:] + 611 20 com.apple.AppKit 0x00007fff8208422f -[NSControl mouseDown:] + 735 21 com.apple.AppKit 0x00007fff82082783 -[NSWindow sendEvent:] + 5068 22 com.apple.AppKit 0x00007fff8204fd46 -[NSApplication sendEvent:] + 5089 23 com.apple.AppKit 0x00007fff81faa562 -[NSApplication run] + 497 24 com.apple.AppKit 0x00007fff81f772f0 NSApplicationMain + 373 25 com.NZBVortex.NZBVortex 0x0000000100012a69 main + 9 26 com.NZBVortex.NZBVortex 0x0000000100001a84 start + 52 Crash 3 Process: NZBVortex [43520] Path: /Users/cero/Downloads/NZBVortex.app/Contents/MacOS/NZBVortex Identifier: com.NZBVortex.NZBVortex Version: 0.5.5 (0.5.5) Code Type: X86-64 (Native) Parent Process: launchd [97] Interval Since Last Report: 23487 sec Crashes Since Last Report: 2 Per-App Interval Since Last Report: 2025 sec Per-App Crashes Since Last Report: 1 Date/Time: 2010-03-23 22:59:05.484 +0100 OS Version: Mac OS X 10.5.8 (9L31a) Report Version: 6 Anonymous UUID: 98AB0386-590B-4E0D-B7AC-3F7AA4E7238E Exception Type: EXC_BAD_INSTRUCTION (SIGILL) Exception Codes: 0x0000000000000001, 0x0000000000000000 Crashed Thread: 0 Application Specific Information: objc[43520]: alt handlers in objc runtime are buggy! Thread 0 Crashed: 0 libobjc.A.dylib 0x00007fff82baef6e _objc_fatal + 238 1 libobjc.A.dylib 0x00007fff82bb2ea4 objc_addExceptionHandler + 302 2 com.apple.CoreFoundation 0x00007fff842b1090 _CFDoExceptionOperation + 528 3 com.apple.AppKit 0x00007fff81f75e26 _NSAppKitLock + 81 4 com.apple.AppKit 0x00007fff81f80f8f -[NSView nextKeyView] + 56 5 com.apple.AppKit 0x00007fff81f81018 -[NSView _primitiveSetNextKeyView:] + 72 6 com.apple.AppKit 0x00007fff820732b1 -[NSView _recursiveSetDefaultKeyViewLoop] + 242 7 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 8 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 9 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 10 com.apple.AppKit 0x00007fff82073300 -[NSView _recursiveSetDefaultKeyViewLoop] + 321 11 com.apple.AppKit 0x00007fff82072fc3 -[NSView _setDefaultKeyViewLoop] + 279 12 com.apple.AppKit 0x00007fff82072e70 -[NSWindow recalculateKeyViewLoop] + 36 13 com.apple.AppKit 0x00007fff821dd149 -[NSSavePanel(NSSavePanelRuntime) _loadPreviousModeAndLayout] + 39 14 com.apple.AppKit 0x00007fff821dcf9e -[NSSavePanel(NSSavePanelRuntime) runModalForDirectory:file:types:] + 71 15 com.NZBVortex.NZBVortex 0x000000010000b7ee -[MainWindowViewController openNZBFileButtonClick:] + 62 16 com.apple.AppKit 0x00007fff821c96bf -[NSToolbarButton sendAction:to:] + 77 17 com.apple.AppKit 0x00007fff821c8bb7 -[NSToolbarItemViewer mouseDown:] + 5362 18 com.apple.AppKit 0x00007fff82082783 -[NSWindow sendEvent:] + 5068 19 com.apple.AppKit 0x00007fff8204fd46 -[NSApplication sendEvent:] + 5089 20 com.apple.AppKit 0x00007fff81faa562 -[NSApplication run] + 497 21 com.apple.AppKit 0x00007fff81f772f0 NSApplicationMain + 373 22 com.NZBVortex.NZBVortex 0x0000000100012a69 main + 9 23 com.NZBVortex.NZBVortex 0x0000000100001a84 start + 52

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• Resulting .exe from PyInstaller with wxPython crashing

  - by Helgi Hrafn Gunnarsson

  I'm trying to compile a very simple wxPython script into an executable by using PyInstaller on Windows Vista. The Python script is nothing but a Hello World in wxPython. I'm trying to get that up and running as a Windows executable before I add any of the features that the program needs to have. But I'm already stuck. I've jumped through some loops in regards to MSVCR90.DLL, MSVCP90.DLL and MSVCPM90.DLL, which I ended up copying from my Visual Studio installation (C:\Program Files\Microsoft Visual Studio 9.0\VC\redist\x86\Microsoft.VC90.CRT). As according to the instructions for PyInstaller, I run: Command: Configure.py Output: I: computing EXE_dependencies I: Finding TCL/TK... I: could not find TCL/TK I: testing for Zlib... I: ... Zlib available I: Testing for ability to set icons, version resources... I: ... resource update available I: Testing for Unicode support... I: ... Unicode available I: testing for UPX... I: ...UPX available I: computing PYZ dependencies... So far, so good. I continue. Command: Makespec.py -F guitest.py Output: wrote C:\Code\PromoUSB\guitest.spec now run Build.py to build the executable Then there's the final command. Command: Build.py guitest.spec Output: checking Analysis building Analysis because out0.toc non existent running Analysis out0.toc Analyzing: C:\Python26\pyinstaller-1.3\support\_mountzlib.py Analyzing: C:\Python26\pyinstaller-1.3\support\useUnicode.py Analyzing: guitest.py Warnings written to C:\Code\PromoUSB\warnguitest.txt checking PYZ rebuilding out1.toc because out1.pyz is missing building PYZ out1.toc checking PKG rebuilding out3.toc because out3.pkg is missing building PKG out3.pkg checking ELFEXE rebuilding out2.toc because guitest.exe missing building ELFEXE out2.toc I get the resulting 'guitest.exe' file, but upon execution, it "simply crashes"... and there is no debug info. It's just one of those standard Windows Vista crashes. The script itself, guitest.py runs just fine by itself. It only crashes as an executable, and I'm completely lost. I don't even know what to look for, since nothing I've tried has returned any relevant results. Another file is generated as a result of the compilation process, called 'warnguitest.txt'. Here are its contents. W: no module named posix (conditional import by os) W: no module named optik.__all__ (top-level import by optparse) W: no module named readline (delayed, conditional import by cmd) W: no module named readline (delayed import by pdb) W: no module named pwd (delayed, conditional import by posixpath) W: no module named org (top-level import by pickle) W: no module named posix (delayed, conditional import by iu) W: no module named fcntl (conditional import by subprocess) W: no module named org (top-level import by copy) W: no module named _emx_link (conditional import by os) W: no module named optik.__version__ (top-level import by optparse) W: no module named fcntl (top-level import by tempfile) W: __all__ is built strangely at line 0 - collections (C:\Python26\lib\collections.pyc) W: delayed exec statement detected at line 0 - collections (C:\Python26\lib\collections.pyc) W: delayed conditional __import__ hack detected at line 0 - doctest (C:\Python26\lib\doctest.pyc) W: delayed exec statement detected at line 0 - doctest (C:\Python26\lib\doctest.pyc) W: delayed conditional __import__ hack detected at line 0 - doctest (C:\Python26\lib\doctest.pyc) W: delayed __import__ hack detected at line 0 - encodings (C:\Python26\lib\encodings\__init__.pyc) W: __all__ is built strangely at line 0 - optparse (C:\Python26\pyinstaller-1.3\optparse.pyc) W: __all__ is built strangely at line 0 - dis (C:\Python26\lib\dis.pyc) W: delayed eval hack detected at line 0 - os (C:\Python26\lib\os.pyc) W: __all__ is built strangely at line 0 - __future__ (C:\Python26\lib\__future__.pyc) W: delayed conditional __import__ hack detected at line 0 - unittest (C:\Python26\lib\unittest.pyc) W: delayed conditional __import__ hack detected at line 0 - unittest (C:\Python26\lib\unittest.pyc) W: __all__ is built strangely at line 0 - tokenize (C:\Python26\lib\tokenize.pyc) W: __all__ is built strangely at line 0 - wx (C:\Python26\lib\site-packages\wx-2.8-msw-unicode\wx\__init__.pyc) W: __all__ is built strangely at line 0 - wx (C:\Python26\lib\site-packages\wx-2.8-msw-unicode\wx\__init__.pyc) W: delayed exec statement detected at line 0 - bdb (C:\Python26\lib\bdb.pyc) W: delayed eval hack detected at line 0 - bdb (C:\Python26\lib\bdb.pyc) W: delayed eval hack detected at line 0 - bdb (C:\Python26\lib\bdb.pyc) W: delayed __import__ hack detected at line 0 - pickle (C:\Python26\lib\pickle.pyc) W: delayed __import__ hack detected at line 0 - pickle (C:\Python26\lib\pickle.pyc) W: delayed conditional exec statement detected at line 0 - iu (C:\Python26\pyinstaller-1.3\iu.pyc) W: delayed conditional exec statement detected at line 0 - iu (C:\Python26\pyinstaller-1.3\iu.pyc) W: delayed eval hack detected at line 0 - gettext (C:\Python26\lib\gettext.pyc) W: delayed __import__ hack detected at line 0 - optik.option_parser (C:\Python26\pyinstaller-1.3\optik\option_parser.pyc) W: delayed conditional eval hack detected at line 0 - warnings (C:\Python26\lib\warnings.pyc) W: delayed conditional __import__ hack detected at line 0 - warnings (C:\Python26\lib\warnings.pyc) W: __all__ is built strangely at line 0 - optik (C:\Python26\pyinstaller-1.3\optik\__init__.pyc) W: delayed exec statement detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed conditional eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed conditional eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) I don't know what the heck to make of any of that. Again, my searches have been fruitless.

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• Android programming - How to acces [to draw on] XML view in main.xml layout, using code

  - by user556248

  Ok I'm a newbie at Android programming, have a hard time with the graphics part. Understand the beauty of creating layout in XML file, but lost how to access various elements, especially a View element to draw on it. See example of my layout main.xml here; <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/root" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/Title" android:text="App title" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textColor="#000000" android:background="#A0A0FF"/> </LinearLayout> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/PaperLayout" android:layout_width="fill_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal" android:focusable="true"> <View android:id="@+id/Paper" android:layout_width="fill_parent" android:layout_height="fill_parent" /> </LinearLayout> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <Button android:id="@+id/File" android:layout_width="fill_parent" android:layout_weight="1" android:layout_height="34dp" android:layout_alignParentTop="true" android:layout_centerInParent="true" android:clickable="true" android:textSize="10sp" android:text="File" /> <Button android:id="@+id/Edit" android:layout_width="fill_parent" android:layout_weight="1" android:layout_height="34dp" android:clickable="true" android:textSize="10sp" android:text="Edit" /> </LinearLayout> </LinearLayout> As you can see I have a custom app title bar, then a View filling middle, and finally two buttons in bottom. Catching button events and responding to, for example changing title bar text and changing View background color works fine, but how the heck do I access and more importantly draw on the view defined in main.xml UPDATE: That for your suggestion, however besides that I need a View, not ImageView and you are missing a parameter on canvas.drawText and an ending bracket, it does not work. Now this is most likely because you missed the fact that I am a newbie and assuming I can fill in any blanks. Now first of all I do NOT understand why in my main.xml layout file I can create a View or even a SurfaceView element, which is what I need, but according to your solution I don't even specify the View like Anyways I edited my main.xml according to your solution, and slimmed it down a bit for simplicity; <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/root" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/Title" android:text="App title" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textColor="#000000" android:background="#A0A0FF"/> </LinearLayout> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/PaperLayout" android:layout_width="fill_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal" android:focusable="true"> <com.example.MyApp.CustomView android:id="@+id/Paper" android:layout_width="fill_parent" android:layout_height="fill_parent" /> <com.example.colorbook.CustomView/> </LinearLayout> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <Button android:id="@+id/File" android:layout_width="fill_parent" android:layout_weight="1" android:layout_height="34dp" android:layout_alignParentTop="true" android:layout_centerInParent="true" android:clickable="true" android:textSize="10sp" android:text="File" /> </LinearLayout> </LinearLayout> In my main java file, MyApp.java, I added this after OnCreate; public class CustomView extends ImageView { @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawText("Your Text", 1, 1, null); } } But I get error on the "CustomView" part; "Implicit super constructor ImageView() is undefined for default constructor.Must define an explicit constructor" Eclipse suggests 3 quick fixes about adding constructor, but none helps, well it removes error but gives error on app when running. I hope somebody can break this down for me and provide a solution, and perhaps explain why I can't just create a View element in my main.xml layotu file and draw on it in code.

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• I never really understood: what is CGI?

  - by claws

  CGI is a Comman Gateway Interface. As the name says, it is a "common" gateway interface for everything. It is so trivial and naive from the name. I feel that I understood this and I felt this every time I encountered this word. But frankly, I didn't. I'm still confused. I am a PHP programmer. I did lot of web development. user (client) request for page --- webserver(-embedded PHP interpreter) ---- Server side(PHP) Script --- MySQL Server. Now say my PHP Script can fetch results from MySQL Server && MATLAB Server && Some other server. So, now PHP Script is the CGI? because its interface for the between webserver & All other servers? I don't know. Sometimes they call CGI, a technology & othertimes they call CGI a program or someother server. What exactly is CGI? Whats the big deal with /cgi-bin/*.cgi? Whats up with this? I don't know what is this cgi-bin directory on the server for. I don't know why they have *.cgi extensions. Why does Perl always comes in the way. CGI & Perl (language). I also don't know whats up with these two. Almost all the time I keep hearing these two in combination "CGI & Perl". This book is another great example CGI Programming with Perl Why not "CGI Programming with PHP/JSP/ASP". I never saw such things. CGI Programming in C this confuses me a lot. in C?? Seriously?? I don't know what to say. I"m just confused. "in C"?? This changes everything. Program needs to be compiled and executed. This entirely changes my view of web programming. When do I compile? How does the program gets executed (because it will be a machine code, so it must execute as a independent process). How does it communicate with the web server? IPC? and interfacing with all the servers (in my example MATLAB & MySQL) using socket programming? I'm lost!! They say that CGI is depreciated. Its no more in use. Is it so? What is its latest update? Once, I ran into a situation where I had to give HTTP PUT request access to web server (Apache HTTPD). Its a long back. So, as far as I remember this is what I did: Edited the configuration file of Apache HTTPD to tell webserver to pass all HTTP PUT requests to some put.php ( I had to write this PHP script) Implement put.php to handle the request (save the file to the location mentioned) People said that I wrote a CGI Script. Seriously, I didn't have clue what they were talking about. Did I really write CGI Script? I hope you understood what my confusion is. (Because I myself don't know where I'm confused). I request you guys to keep your answer as simple as possible. I really can't understand any fancy technical terminology. At least not in this case. EDIT: I found this amazing tutorial "CGI Programming Is Simple!" - CGI Tutorial Which explains the concepts in simplest possible way. I've only have one complaint about this tutorial. Just to make what ever he explained complete he should have shown the C code he used for generating response for those GET / POST requests. I've also added link to this tutorial to Wikipedia's article : http://en.wikipedia.org/wiki/Common_Gateway_Interface

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• Java image conversion to RGB565

  - by Vladimir

  I try to convert image to RGB565 format. I read this image: BufferedImage bufImg = ImageIO.read(imagePathFile); sendImg = new BufferedImage(CONTROLLER_LCD_WIDTH/*320*/, CONTROLLER_LCD_HEIGHT/*240*/, BufferedImage.TYPE_USHORT_565_RGB); sendImg .getGraphics().drawImage(bufImg, 0, 0, CONTROLLER_LCD_WIDTH/*320*/, CONTROLLER_LCD_HEIGHT/*240*/, null); Here is it: Then I convert it to RGB565: int numByte=0; byte[] OutputImageArray = new byte[CONTROLLER_LCD_WIDTH*CONTROLLER_LCD_HEIGHT*2]; int i=0; int j=0; int len = OutputImageArray.length; for (i=0;i<CONTROLLER_LCD_WIDTH;i++) { for (j=0;j<CONTROLLER_LCD_HEIGHT;j++) { Color c = new Color(sendImg.getRGB(i, j)); int aRGBpix = sendImg.getRGB(i, j); int alpha; int red = c.getRed(); int green = c.getGreen(); int blue = c.getBlue(); //RGB888 red = (aRGBpix >> 16) & 0x0FF; green = (aRGBpix >> 8) & 0x0FF; blue = (aRGBpix >> 0) & 0x0FF; alpha = (aRGBpix >> 24) & 0x0FF; //RGB565 red = red >> 3; green = green >> 2; blue = blue >> 3; //A pixel is represented by a 4-byte (32 bit) integer, like so: //00000000 00000000 00000000 11111111 //^ Alpha ^Red ^Green ^Blue //Converting to RGB565 short pixel_to_send = 0; int pixel_to_send_int = 0; pixel_to_send_int = (red << 11) | (green << 5) | (blue); pixel_to_send = (short) pixel_to_send_int; //dividing into bytes byte byteH=(byte)((pixel_to_send >> 8) & 0x0FF); byte byteL=(byte)(pixel_to_send & 0x0FF); //Writing it to array - High-byte is second OutputImageArray[numByte]=byteH; OutputImageArray[numByte+1]=byteL; numByte+=2; } } Then I try to restore this from resulting array OutputImageArray: i=0; j=0; numByte=0; BufferedImage NewImg = new BufferedImage(CONTROLLER_LCD_WIDTH, CONTROLLER_LCD_HEIGHT, BufferedImage.TYPE_USHORT_565_RGB); for (i=0;i<CONTROLLER_LCD_WIDTH;i++) { for (j=0;j<CONTROLLER_LCD_HEIGHT;j++) { int curPixel=0; int alpha=0x0FF; int red; int green; int blue; byte byteL=0; byte byteH=0; byteH = OutputImageArray[numByte]; byteL = OutputImageArray[numByte+1]; curPixel= (byteH << 8) | (byteL); //RGB565 red = (curPixel >> (6+5)) & 0x01F; green = (curPixel >> 5) & 0x03F; blue = (curPixel) & 0x01F; //RGB888 red = red << 3; green = green << 2; blue = blue << 3; //aRGB curPixel = 0; curPixel = (alpha << 24) | (red << 16) | (green << 8) | (blue); NewImg.setRGB(i, j, curPixel); numByte+=2; } } I output this restored image. But I see that it looks very poor. I expected the lost of pictures quality. But as I thought, this picture has to have almost the same quality as the previous picture. - Is it right? Is my code right?

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• Migrating Ruby Site from EngineYard to Heroku

  - by user410925

  As part of a larger project I've been tasked with migrating some existing Ruby on Rails sites (built with an old version of refinerycms 0.9.6.34, at least that's the version listed in the Gemfile included with the source). I don't normally work with Ruby so I'm at a bit of a loss. The previous developers simply handed over the latest git dump as well as a db dump. I'm working first with trying to get the site up working locally on an Ubuntu 11.10 local machine before pushing up to at test Heroku install. If it's possible to just push directly to Heroku with the files they gave, then I can try that, but it's my understanding I need to get everything working and then use Heroku's tools to deploy. The previous devs said they're using ruby 1.8.7 so in Ubuntu I've done the following: aptitude install ruby1.8 ruby1.8-dev ruby1.8-full aptitude install rubygems1.8 I've restored the database and in the config directory I've made changes to the database.yml to point to the restored database. When I try and run "bundle install" from the root of the extracted source dir I get: Invalid gemspec in [/var/lib/gems/1.8/specifications/mail-2.4.4.gemspec]: invalid date format in specification: "2012-03-14 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/tilt-1.3.3.gemspec]: invalid date format in specification: "2011-08-25 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/mime-types-1.18.gemspec]: invalid date format in specification: "2012-03-21 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/sass-rails-3.2.5.gemspec]: invalid date format in specification: "2012-03-19 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/jquery-rails-2.0.2.gemspec]: invalid date format in specification: "2012-04-03 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/mail-2.4.4.gemspec]: invalid date format in specification: "2012-03-14 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/tilt-1.3.3.gemspec]: invalid date format in specification: "2011-08-25 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/mime-types-1.18.gemspec]: invalid date format in specification: "2012-03-21 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/sass-rails-3.2.5.gemspec]: invalid date format in specification: "2012-03-19 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/jquery-rails-2.0.2.gemspec]: invalid date format in specification: "2012-04-03 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/mail-2.4.4.gemspec]: invalid date format in specification: "2012-03-14 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/tilt-1.3.3.gemspec]: invalid date format in specification: "2011-08-25 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/mime-types-1.18.gemspec]: invalid date format in specification: "2012-03-21 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/sass-rails-3.2.5.gemspec]: invalid date format in specification: "2012-03-19 00:00:00.000000000Z" Invalid gemspec in [/var/lib/gems/1.8/specifications/jquery-rails-2.0.2.gemspec]: invalid date format in specification: "2012-04-03 00:00:00.000000000Z" Fetching gem metadata from https://rubygems.org/....... Fetching gem metadata from https://rubygems.org/.. Using rake (0.9.2.2) Using i18n (0.6.0) Using multi_json (1.3.6) Using activesupport (3.2.3) Using builder (3.0.0) Using activemodel (3.2.3) Using erubis (2.7.0) Using journey (1.0.3) Using rack (1.4.1) Using rack-cache (1.2) Using rack-test (0.6.1) Using hike (1.2.1) Installing tilt (1.3.3) Using sprockets (2.1.3) Using actionpack (3.2.3) Installing mime-types (1.18) Using polyglot (0.3.3) Using treetop (1.4.10) Installing mail (2.4.4) Using actionmailer (3.2.3) Using arel (3.0.2) Using tzinfo (0.3.33) Using activerecord (3.2.3) Using activeresource (3.2.3) Using acts_as_indexed (0.7.8) Using awesome_nested_set (2.1.3) Using babosa (0.3.7) Using bcrypt-ruby (3.0.1) Using coffee-script-source (1.3.3) Using execjs (1.4.0) Using coffee-script (2.2.0) Using rack-ssl (1.3.2) Using json (1.7.3) Using rdoc (3.12) Using thor (0.14.6) Using railties (3.2.3) Using coffee-rails (3.2.2) Using orm_adapter (0.0.7) Using warden (1.1.1) Using devise (2.0.4) Using dragonfly (0.9.12) Using friendly_id (4.0.6) Using paper_trail (2.6.3) Using globalize3 (0.2.0) Installing jquery-rails (2.0.2) Using bundler (1.1.4) Using rails (3.2.3) Using sass (3.1.19) Installing sass-rails (3.2.5) Using truncate_html (0.5.5) Using uglifier (1.2.4) Using will_paginate (3.0.3) Using refinerycms-core (2.0.4) Using refinerycms-authentication (2.0.4) Using refinerycms-dashboard (2.0.4) Using refinerycms-images (2.0.4) Using seo_meta (1.3.0) Using refinerycms-pages (2.0.4) Using refinerycms-resources (2.0.4) Using refinerycms (2.0.4) Using routing-filter (0.3.1) Using refinerycms-i18n (2.0.0) Using sqlite3 (1.3.6) Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed. Obviously the errors with Invalid gemspec need to be resolved, but the other thing that's troubling to me are the lines: Using refinerycms-core (2.0.4) Using refinerycms-authentication (2.0.4) Using refinerycms-dashboard (2.0.4) Using refinerycms-images (2.0.4) Using seo_meta (1.3.0) Using refinerycms-pages (2.0.4) Using refinerycms-resources (2.0.4) Using refinerycms (2.0.4) Using routing-filter (0.3.1) Using refinerycms-i18n (2.0.0) Since the refinerycms version listed in the Gemfile was 0.9.6.34. When it comes to the Ruby world, I'm a bit lost so any help would be greatly appreciated. Thanks,

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• java.sql.SQLException: Operation not allowed after ResultSet closed

  - by javatraniee

  Why am I getting an Resultset already closed error? public class Server implements Runnable { private static int port = 1600, maxConnections = 0; public static Connection connnew = null; public static Connection connnew1 = null; public static Statement stnew, stnew1, stnew2, stnew3, stnew4; public void getConnection() { try { Class.forName("org.gjt.mm.mysql.Driver"); connnew = DriverManager.getConnection("jdbc:mysql://localhost/db_alldata", "root", "flashkit"); connnew1 = DriverManager.getConnection("jdbc:mysql://localhost/db_main", "root", "flashkit"); stnew = connnew.createStatement(); stnew1 = connnew.createStatement(); stnew2 = connnew1.createStatement(); stnew3 = connnew1.createStatement(); stnew4 = connnew1.createStatement(); } catch (Exception e) { System.out.print("Get Connection Exception---" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "----- > " + e); } } public void closeConnection() { try { if (!(connnew.isClosed())) { stnew.close(); stnew1.close(); connnew.close(); } if (!(connnew1.isClosed())) { stnew2.close(); stnew3.close(); stnew4.close(); connnew1.close(); } } catch (Exception e) { System.out.print("Close Connection Closing Exception-----" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "------->" + e); } } Server() { try { } catch (Exception ee) { System.out.print("Server Exceptions in main connection--" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "------>" + ee); } } public static void main(String[] args) throws SQLException { int i = 0; Server STUD = new Server(); STUD.getConnection(); try { ServerSocket listener = new ServerSocket(port); Socket server; while ((i++ < maxConnections) || (maxConnections == 0)) { @SuppressWarnings("unused") doComms connection; server = listener.accept(); try { ResultSet checkconnection = stnew4 .executeQuery("select count(*) from t_studentdetails"); if (checkconnection.next()) { // DO NOTHING IF EXCEPTION THEN CLOSE ALL CONNECTIONS AND OPEN NEW // CONNECTIONS } } catch (Exception e) { System.out.print("Db Connection Lost Closing And Re-Opning It--------" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "--------" + e); STUD.closeConnection(); STUD.getConnection(); } doComms conn_c = new doComms(server, stnew, stnew1, stnew2, stnew3); Thread t = new Thread(conn_c); t.start(); } } catch (IOException ioe) { System.out.println("Main IOException on socket listen: " + ioe); } } public void run() { } } class doComms implements Runnable { private Socket server; private String input; static Connection conn = null; static Connection conn1 = null; static Statement st, st1, st2, st3; doComms(Socket server, Statement st, Statement st1, Statement st2, Statement st3) { this.server = server; doComms.st = st; doComms.st1 = st1; doComms.st2 = st2; doComms.st3 = st3; } @SuppressWarnings("deprecation") public void run() { input = ""; // char ch; try { DataInputStream in = new DataInputStream(server.getInputStream()); OutputStreamWriter outgoing = new OutputStreamWriter(server.getOutputStream()); while (!(null == (input = in.readLine()))) { savetodatabase(input, server.getPort(), outgoing); } } catch (IOException ioe) { System.out.println("RUN IOException on socket listen:-------" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "----- " + ioe); ioe.printStackTrace(); } } public void savetodatabase(String line, int port1, OutputStreamWriter outgoing) { try { String Rollno = "-", name = "-", div = "-", storeddate = "-", storedtime = "-", mailfrom = ""; String newline = line; String unitid = "-"; storeddate = new SimpleDateFormat("yyyy-MM-dd").format(new java.util.Date()); storedtime = new SimpleDateFormat("HH:mm:ss").format(new java.util.Date()); String sql2 = "delete from t_currentport where PortNumber='" + port1 + "''"; st2.executeUpdate(sql2); sql2 = "insert into t_currentport (unitid, portnumber,thedate,thetime) values >('" + unitid + "','" + port1 + "','" + storeddate + "','" + storedtime + "')"; st2.executeUpdate(sql2); String tablename = GetTable(); String sql = "select * from t_studentdetails where Unitid='" + unitid + "'"; ResultSet rst = st2.executeQuery(sql); if (rst.next()) { Rollno = rst.getString("Rollno"); name = rst.getString("name"); div = rst.getString("div"); } String sql1 = "insert into studentInfo StoredDate,StoredTime,Subject,UnitId,Body,Status,Rollno,div,VehId,MailDate,MailTime,MailFrom,MailTo,Header,UnProcessedStamps) values('" + storeddate + "','" + storedtime + "','" + unitid + "','" + unitid + "','" + newline + "','Pending','" + Rollno + "','" + div + "','" + name + "','" + storeddate + "','" + storedtime + "','" + mailfrom + "','" + mailfrom + "','-','-')"; st1.executeUpdate(sql1); } catch (Exception e) { System.out.print("Save to db Connection Exception--" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "-->" + e); } } }

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• PHP Form not working IE and Chrome, but fine in FF

  - by RO

  <? if(isset($_POST['accountUser']) && isset($_POST['accountPassword'])) { include("dbase.php"); include("settings.php"); if ($_POST['accountType']=="member") { $database="chatusers"; } else if ($_POST['accountType']=="model") { $database="chatmodels"; } else if ($_POST['accountType']=="studioop") { $database="chatoperators"; } $userExists=false; $result = mysql_query("SELECT id,user,password,status FROM $database WHERE status!='pending' AND status!='rejected' "); while($row = mysql_fetch_array($result)) { $tempUser=$row["user"]; $tempPass=$row["password"]; $tempId=$row["id"]; if ($_POST['accountUser']==$tempUser && md5($_POST['accountPassword'])==$tempPass) { if ($row["status"]=="blocked") { $userExists=true; $errorMsg="Account is blocked, please contact the administrator for more details"; } else { $userExists=true; $currentTime=time(); mysql_query("UPDATE $database SET lastLogIn='$currentTime' WHERE id = '$tempId' LIMIT 1"); setcookie("usertype", $database, time()+3600); setcookie("id", $tempId, time()+3600); header("Location: cp/$database/"); } } } if (!$userExists){ $errorMsg="Wrong Username or password"; } } else if (isset($_GET['from']) && $_GET['from']=="recoverpass"){ $errorMsg="Your new password has been sent to your mail"; } else { $errorMsg="Please complete username and password fields"; } ?> <? include("_main.header.php"); ?> <table width="720" height="200" border="0" align="center" cellpadding="0" cellspacing="0"> <tr> <td align="center" valign="middle"><form action="login.php" method="post" enctype="application/x-www-form-urlencoded" name="form1"> <p>&nbsp;</p> <table width="720" border="0" align="center"> <tr> <td colspan="2"><p align="left"> <span class="error"><?php if ( isset($errorMsg) && $errorMsg!=""){ echo $errorMsg; } ?></span> <br> <br> </p></td> </tr> <tr> <td width="210" align="right" valign="top" class="form_definitions"><div align="right">Username:</div></td> <td align="left" valign="top"><input name="accountUser" type="text" id="accountUser" value="<? echo $_GET[user];?>" size="24" maxlength="24"></td> </tr> <tr> <td align="right" valign="top" class="form_definitions"><div align="right">Password:</div></td> <td align="left" valign="top"><input name="accountPassword" type="password" id="accountPassword2" size="24" maxlength="24"></td> </tr> <tr> <td align="right" valign="top" class="form_definitions"><div align="right">Account type:</div></td> <td align="left" valign="top"> <select name="accountType" id="select"> <option value="member" selected>Member</option> <option value="model">Model</option> <option value="studioop">Studio Operator</option> </select> <div align="left"></div></td> </tr> <tr> <td align="right" valign="top" class="form_definitions">&nbsp;</td> <td align="left" valign="top"> <input type="submit" name="Submit" value="Log In to your account"> <div align="left"></div></td> </tr> <tr> <td align="right" valign="top" class="form_definitions">&nbsp;</td> <td align="left" valign="top"><a href="lostpassword.php" class="left">Lost Password? Press Here!</a></td> </tr> </table> </form></td> </tr> </table> <br> <br> <? include("_main.footer.php"); ?>

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• asp.net - csharp - jquery - looking for a better and usage solution

  - by LostLord

  hi my dear friends i have a little problem about using jquery...(i reeally do not know jquery but i forced to use it) i am using vs 2008 - asp.net web app with c# also i am using telerik controls in my pages also i am using sqldatasources (Connecting to storedprocedures) in my pages my pages base on master and content pages and in content pages i have mutiviews ================================================================================= in one of the views(inside one of those multiviews)i had made two radcombo boxes for country and city requirement like cascading dropdowns as parent and child combo boxes. i used old way for doing that , i mean i used update panel and in the SelectedIndexChange Event of Parent RadComboBox(Country) i Wrote this code : protected void RadcomboboxCountry_SelectedIndexChanged(object o, RadComboBoxSelectedIndexChangedEventArgs e) { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } my child radcombo box can fill by upper code , let me tell you how : the child sqldatasource have a sp that has a parameter and i fill that parameter by this line - hfSelectedCo_ID.Value = RadcbCoNameInInsert.SelectedValue; RadcbCoNameInInsert.SelectedValue means country ID. after doing that SelectedIndexChange Event of Parent RadComboBox(Country) could not be fire therefore i forced to set the autopostback property to true. afetr doing that every thing was ok until some one told me can u control focus and keydown of your radcombo boxes (when u press enter key on the parent combobox[country] , so child combobox gets focus -- and when u press upperkey on child radcombobox [city], so parent combobox[country] gets focus) (For Users That Do Not Want To Use Mouse for Input Info And Choose items) i told him this is web app , not win form and we can not do that. i googled it and i found jquery the only way for doing that ... so i started using jquery . i wrote this code with jquery for both of them : <script src="../JQuery/jquery-1.4.1.js" language="javascript" type="text/javascript"></script> <script type="text/javascript"> $(function() { $('input[id$=RadcomboboxCountry_Input]').focus(); $('input[id$=RadcomboboxCountry_Input]').select(); $('input[id$=RadcomboboxCountry_Input]').bind('keyup', function(e) { var code = (e.keyCode ? e.keyCode : e.which); if (code == 13) { -----------> Enter Key $('input[id$=RadcomboboxCity_Input]').focus(); $('input[id$=RadcomboboxCity_Input]').select(); } }); $('input[id$=RadcomboboxCity_Input]').bind('keyup', function(e) { var code = (e.keyCode ? e.keyCode : e.which); if (code == 38) { -----------> Upper Key $('input[id$=RadcomboboxCountry_Input]').focus(); $('input[id$=RadcomboboxCountry_Input]').select(); } }); }); </script> this jquery code worked BBBBBBUUUUUUUTTTTTT autopostback=true of the Parent RadComboBox Became A Problem , Because when SelectedIndex Change Of ParentRadComboBox is fired after that Telerik Skins runs and after that i lost parent ComboBox Focus and we should use mouse but we don't want it.... for fix this problem i decided to set autopostback of perentCB to false and convert protected void RadcomboboxCountry_SelectedIndexChanged(object o, RadComboBoxSelectedIndexChangedEventArgs e) { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } to a public non static method without parameters and call it with jquey like this : (i used onclientchanged property of parentcombo box like onclientchanged = "MyMethodForParentCB_InJquery();" insread of selectedindexchange event) public void MyMethodForParentCB_InCodeBehind() { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } for doing that i read the blow manual and do that step by step : ======================================================================= http://www.ajaxprojects.com/ajax/tutorialdetails.php?itemid=732 ======================================================================= but this manual is about static methods and this is my new problem ... when i am using static method like : public static void MyMethodForParentCB_InCodeBehind() { hfSelectedCo_ID.Value = RadcomboboxCountry.SelectedValue; RadcomboboxCity.Items.Clear(); RadcomboboxCity.Items.Add(new RadComboBoxItem(" ...", "5")); RadcomboboxCity.DataBind(); RadcomboboxCity.SelectedIndex = 0; } so i recieved some errors and this method could not recognize my controls and hidden field... one of those errors like this : Error 2 An object reference is required for the non-static field, method, or property 'Darman.SuperAdmin.Users.hfSelectedCo_ID' C:\Javad\Copy of Darman 6\Darman\SuperAdmin\Users.aspx.cs 231 13 Darman any idea or is there any way to call non static methods with jquery (i know we can not do that but is there another way to solve my problem)???????????????

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• Problem with building tree bottom up

  - by Esmond

  Hi, I have problems building a binary tree from the bottom up. THe input of the tree would be internal nodes of the trees with the children of this node being the leaves of the eventual tree. So initially if the tree is empty the root would be the first internal node. Afterwards, The next internal node to be added would be the new root(NR), with the old root(OR) being one of the child of NR. And so on. The problem i have is that whenever i add a NR, the children of the OR seems to be lost when i do a inOrder traversal. This is proven to be the case when i do a getSize() call which returns the same number of nodes before and after addNode(Tree,Node) Any help with resolving this problem is appreciated edited with the inclusion of node class code. both tree and node classes have the addChild methods because i'm not very sure where to put them for it to be appropriated. any comments on this would be appreciated too. The code is as follows: import java.util.*; public class Tree { Node root; int size; public Tree() { root = null; } public Tree(Node root) { this.root = root; } public static void setChild(Node parent, Node child, double weight) throws ItemNotFoundException { if (parent.child1 != null && parent.child2 != null) { throw new ItemNotFoundException("This Node already has 2 children"); } else if (parent.child1 != null) { parent.child2 = child; child.parent = parent; parent.c2Weight = weight; } else { parent.child1 = child; child.parent = parent; parent.c1Weight = weight; } } public static void setChild1(Node parent, Node child) { parent.child1 = child; child.parent = parent; } public static void setChild2(Node parent, Node child) { parent.child2 = child; child.parent = parent; } public static Tree addNode(Tree tree, Node node) throws ItemNotFoundException { Tree tree1; if (tree.root == null) { tree.root = node; } else if (tree.root.getSeq().equals(node.getChild1().getSeq()) || tree.root.getSeq().equals(node.getChild2().getSeq())) { Node oldRoot = tree.root; oldRoot.setParent(node); tree.root = node; } else { //form a disjoint tree and merge the 2 trees tree1 = new Tree(node); tree = mergeTree(tree, tree1); } System.out.print("addNode2 = "); if(tree.root != null ) { Tree.inOrder(tree.root); } System.out.println(); return tree; } public static Tree mergeTree(Tree tree, Tree tree1) { String root = "root"; Node node = new Node(root); tree.root.setParent(node); tree1.root.setParent(node); tree.root = node; return tree; } public static int getSize(Node root) { if (root != null) { return 1 + getSize(root.child1) + getSize(root.child2); } else { return 0; } } public static boolean isEmpty(Tree Tree) { return Tree.root == null; } public static void inOrder(Node root) { if (root != null) { inOrder(root.child1); System.out.print(root.sequence + " "); inOrder(root.child2); } } } public class Node { Node child1; Node child2; Node parent; double c1Weight; double c2Weight; String sequence; boolean isInternal; public Node(String seq) { sequence = seq; child1 = null; c1Weight = 0; child2 = null; c2Weight = 0; parent = null; isInternal = false; } public boolean hasChild() { if (this.child1 == null && this.child2 == null) { this.isInternal = false; return isInternal; } else { this.isInternal = true; return isInternal; } } public String getSeq() throws ItemNotFoundException { if (this.sequence == null) { throw new ItemNotFoundException("No such node"); } else { return this.sequence; } } public void setChild(Node child, double weight) throws ItemNotFoundException { if (this.child1 != null && this.child2 != null) { throw new ItemNotFoundException("This Node already has 2 children"); } else if (this.child1 != null) { this.child2 = child; this.c2Weight = weight; } else { this.child1 = child; this.c1Weight = weight; } } public static void setChild1(Node parent, Node child) { parent.child1 = child; child.parent = parent; } public static void setChild2(Node parent, Node child) { parent.child2 = child; child.parent = parent; } public void setParent(Node parent){ this.parent = parent; } public Node getParent() throws ItemNotFoundException { if (this.parent == null) { throw new ItemNotFoundException("This Node has no parent"); } else { return this.parent; } } public Node getChild1() throws ItemNotFoundException { if (this.child1 == null) { throw new ItemNotFoundException("There is no child1"); } else { return this.child1; } } public Node getChild2() throws ItemNotFoundException { if (this.child2 == null) { throw new ItemNotFoundException("There is no child2"); } else { return this.child2; } } }

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• "The usage of semaphores is subtly wrong"

  - by Hoonose

  This past semester I was taking an OS practicum in C, in which the first project involved making a threads package, then writing a multiple producer-consumer program to demonstrate the functionality. However, after getting grading feedback, I lost points for "The usage of semaphores is subtly wrong" and "The program assumes preemption (e.g. uses yield to change control)" (We started with a non-preemptive threads package then added preemption later. Note that the comment and example contradict each other. I believe it doesn't assume either, and would work in both environments). This has been bugging me for a long time - the course staff was kind of overwhelmed, so I couldn't ask them what's wrong with this over the semester. I've spent a long time thinking about this and I can't see the issues. If anyone could take a look and point out the error, or reassure me that there actually isn't a problem, I'd really appreciate it. I believe the syntax should be pretty standard in terms of the thread package functions (minithreads and semaphores), but let me know if anything is confusing. #include <stdio.h> #include <stdlib.h> #include "minithread.h" #include "synch.h" #define BUFFER_SIZE 16 #define MAXCOUNT 100 int buffer[BUFFER_SIZE]; int size, head, tail; int count = 1; int out = 0; int toadd = 0; int toremove = 0; semaphore_t empty; semaphore_t full; semaphore_t count_lock; // Semaphore to keep a lock on the // global variables for maintaining the counts /* Method to handle the working of a student * The ID of a student is the corresponding minithread_id */ int student(int total_burgers) { int n, i; semaphore_P(count_lock); while ((out+toremove) < arg) { n = genintrand(BUFFER_SIZE); n = (n <= total_burgers - (out + toremove)) ? n : total_burgers - (out + toremove); printf("Student %d wants to get %d burgers ...\n", minithread_id(), n); toremove += n; semaphore_V(count_lock); for (i=0; i<n; i++) { semaphore_P(empty); out = buffer[tail]; printf("Student %d is taking burger %d.\n", minithread_id(), out); tail = (tail + 1) % BUFFER_SIZE; size--; toremove--; semaphore_V(full); } semaphore_P(count_lock); } semaphore_V(count_lock); printf("Student %d is done.\n", minithread_id()); return 0; } /* Method to handle the working of a cook * The ID of a cook is the corresponding minithread_id */ int cook(int total_burgers) { int n, i; printf("Creating Cook %d\n",minithread_id()); semaphore_P(count_lock); while ((count+toadd) <= arg) { n = genintrand(BUFFER_SIZE); n = (n <= total_burgers - (count + toadd) + 1) ? n : total_burgers - (count + toadd) + 1; printf("Cook %d wants to put %d burgers into the burger stack ...\n", minithread_id(),n); toadd += n; semaphore_V(count_lock); for (i=0; i<n; i++) { semaphore_P(full); printf("Cook %d is putting burger %d into the burger stack.\n", minithread_id(), count); buffer[head] = count++; head = (head + 1) % BUFFER_SIZE; size++; toadd--; semaphore_V(empty); } semaphore_P(count_lock); } semaphore_V(count_lock); printf("Cook %d is done.\n", minithread_id()); return 0; } /* Method to create our multiple producers and consumers * and start their respective threads by fork */ void starter(int* c){ int i; for (i=0;i<c[2];i++){ minithread_fork(cook, c[0]); } for (i=0;i<c[1];i++){ minithread_fork(student, c[0]); } } /* The arguments are passed as command line parameters * argv[1] is the no of students * argv[2] is the no of cooks */ void main(int argc, char *argv[]) { int pass_args[3]; pass_args[0] = MAXCOUNT; pass_args[1] = atoi(argv[1]); pass_args[2] = atoi(argv[2]); size = head = tail = 0; empty = semaphore_create(); semaphore_initialize(empty, 0); full = semaphore_create(); semaphore_initialize(full, BUFFER_SIZE); count_lock = semaphore_create(); semaphore_initialize(count_lock, 1); minithread_system_initialize(starter, pass_args); }

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• Why is the class wrong for NSFetchRequest?

  - by Stephen Furlani

  Hello, I am working with an undocumented API (Osirix) and I have a sister-question to the one I posted here. I am having trouble loading objects from a managed object context. With loading from API, using their instance of _context and _model 2010-05-28 14:05:13.588 OsiriX[44012:a0f] Entity: Study 2010-05-28 14:05:13.589 OsiriX[44012:a0f] EntityClassName: DicomStudy 2010-05-28 14:05:13.589 OsiriX[44012:a0f] ClassName: DicomStudy With loading from Fetch Request (and my own instance of _context, and _model) 2010-05-28 14:19:09.956 rcOsirix[44431:7a03] Entity: Study 2010-05-28 14:19:09.957 rcOsirix[44431:7a03] EntityClassName: DicomStudy 2010-05-28 14:19:09.958 rcOsirix[44431:7a03] ClassName: NSManagedObject output given by: NSLog(@"Entity: %@",[[item entity] name]); NSLog(@"EntityClassName: %@", [[item entity] managedObjectClassName]); NSLog(@"ClassName: %s", class_getName(object_getClass([item class]))); So it is obvious that even though the Entity thinks it is a DicomSeries - it is not. It is just a NSManagedObject. DicomSeries has some "hard-coded" KVC stuff that I ran into a problem with in my other question. I'm pursuing a different line of reasoning in this thread - with the loading of the objects. The following is their code: - (NSManagedObjectModel *)managedObjectModel { if (managedObjectModel) return managedObjectModel; NSMutableSet *allBundles = [[NSMutableSet alloc] init]; [allBundles addObject: [NSBundle mainBundle]]; [allBundles addObjectsFromArray: [NSBundle allFrameworks]]; managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL: [NSURL fileURLWithPath: [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"/OsiriXDB_DataModel.mom"]]]; [allBundles release]; return managedObjectModel; } - (NSManagedObjectContext *) managedObjectContextLoadIfNecessary:(BOOL) loadIfNecessary { NSError *error = nil; NSString *localizedDescription; NSFileManager *fileManager; if( currentDatabasePath == nil) return nil; if (managedObjectContext) return managedObjectContext; if( loadIfNecessary == NO) return nil; fileManager = [NSFileManager defaultManager]; [persistentStoreCoordinator release]; persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: self.managedObjectModel]; managedObjectContext = [[NSManagedObjectContext alloc] init]; [managedObjectContext setPersistentStoreCoordinator: persistentStoreCoordinator]; NSURL *url = [NSURL fileURLWithPath: currentDatabasePath]; if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:url options:nil error:&error]) { NSLog(@"********** managedObjectContextLoadIfNecessary FAILED: %@", error); localizedDescription = [error localizedDescription]; error = [NSError errorWithDomain:@"OsiriXDomain" code:0 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:error, NSUnderlyingErrorKey, [NSString stringWithFormat:@"Store Configuration Failure: %@", ((localizedDescription != nil) ? localizedDescription : @"Unknown Error")], NSLocalizedDescriptionKey, nil]]; } [[managedObjectContext undoManager] setLevelsOfUndo: 1]; [[managedObjectContext undoManager] disableUndoRegistration]; // This line is very important, if there is NO database.sql file [self saveDatabase: currentDatabasePath]; return managedObjectContext; } This is my code: NSManagedObjectModel* DataModule::managedObjectModel() { if (_managedObjectModel) return _managedObjectModel; NSMutableSet *allBundles = [[NSMutableSet alloc] init]; [allBundles addObject: [NSBundle mainBundle]]; [allBundles addObjectsFromArray: [NSBundle allFrameworks]]; _managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL: [NSURL fileURLWithPath: [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"/OsiriXDB_DataModel.mom"]]]; [allBundles release]; return [_managedObjectModel retain]; } ... NSError *error = nil; [_storeCoordinator release]; _storeCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: managedObjectModel()]; _context = [[NSManagedObjectContext alloc] init]; [_context setPersistentStoreCoordinator: _storeCoordinator]; NSURL *url = [NSURL fileURLWithPath: [[NSString alloc] initWithCString:_DBPath.c_str()]]; if (url == nil) { [pool release]; _loadLock = false; return nil; } if (![_storeCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:url options:nil error:&error]) { NSLog(@"********** managedObjectContextLoadIfNecessary FAILED: %@", error); NSString *localizedDescription = [error localizedDescription]; error = [NSError errorWithDomain:@"OsiriXDomain" code:0 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:error, NSUnderlyingErrorKey, [NSString stringWithFormat:@"Store Configuration Failure: %@", ((localizedDescription != nil) ? localizedDescription : @"Unknown Error")], NSLocalizedDescriptionKey, nil]]; //Exit Failure [pool release]; _loadLock = false; return nil; } [[_context undoManager] setLevelsOfUndo: 1]; [[_context undoManager] disableUndoRegistration]; ... I am including all the same frameworks.... but _allBundles isn't even used to create the managedObjectModel so I don't know what it's supposed to do except load them into memory so that the mom can look at them while loading. Totally lost. Help! Why would objects returned by my FetchRequest with the same Entity come out as NSManagedObjects and not DicomStudys? I'm including DicomStudy.h so it should see the object during creation of the model, context, and fetch request. [request setEntity: [[managedObjectModel() entitiesByName] objectForKey:@"Study"]]; Thanks in advance, -Stephen

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