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• How to animate a path like it's being drawn, dot by dot? (Raphael.js)

  - by Anton

  How to animate a vector path like it's being drawn by hand? In other words, slowly show the path pixel by pixel. I'm using Raphaël.js, but if your answer is not library specific—like maybe there's some general programming pattern for doing that kind of thing (I'm fairly new to vector animation)—it's welcome! Update I know it's easy to do with straight paths, as easy as an example on that page:: path("M114 253").animate({path: "M114 253 L 234 253"}); But try to change code on that page, say, this way:: path("M114 26").animate({path: "M114 26 C 24 23 234 253 234 253"}); And you'll see what I mean. Path is certainly animated from it initial state (point "M114 26") to the end state (curve "C 24 23 234 253 234 253" starting on point "M114 26"), but not in a way specified in question, not like it's being drawn. (Sorry for not making clear from the start that I don't mean animating straight lines.) I don't see how animateAlong can do that either. It can animate an object along a path, and how can I make this path to gradually show itself while object is being animated along it?

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• Fundamentals of Deserialization in .NET?

  - by Codehelp

  I have been working with XML for past couple of months with .NET Basically all the work I do involve XML in oneway of another so I thought it would be good to learn the serialization and deserialization part of the game. My work mostly involves the 'Deserialization' part of it. Almost every time I have an XML file which has to be used by the application that I write. An object form of the XML is the best way to use. Now initially the XML was very straight forward, just a couple of tags which would translate into a class very easily using XSD.exe tool. Things grew a bit complex with nesting of tags and I found Xsd2Code gen tool work fine. During this whole process I have been able to do my work with a lot of help from Stackoverflow community, thanks for that, but I think I have missed the forest for the trees. I need to know how Deserialization works in .NET Fundamentally, I would like to know what happens behind the scenes in taking a XML and converting it into a usable object. Code samples have helped me in the past, and as mentioned earlier the problem get's solved but the learning does not happen. So, if anyone can guide to resources that can get me started on the Deserialization part of the game, I would be thankful to them. Regards.

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• Entity Framework 4 Entity with EntityState of Unchanged firing update

  - by Andy

  I am using EF 4, mapping all CUD operations for my entities using sprocs. I have two tables, ADDRESS and PERSON. A PERSON can have multiple ADDRESS associated with them. Here is the code I am running: Person person = (from p in context.People where p.PersonUID == 1 select p).FirstOrDefault(); Address address = (from a in context.Addresses where a.AddressUID == 51 select a).FirstOrDefault(); address.AddressLn2 = "Test"; context.SaveChanges(); The Address being updated is associated with the Person I am retrieveing - although they are not explicitly linked in any way in the code. When the context.SaveChanges() executes not only does the Update sproc for my Address entity get fired (like you would expect), but so does the Update sproc for the Person entity - even though you can see there was no change made to the Person entity. When I check the EntityState of both objects before the context.SaveChanges() call I see that my Address entity has an EntityState of "Modified" and my Person enity has an EntityState of "Unchanged". Why is the Update sproc being called for the Person entity? Is there a setting of some sort that I can set to prevent this from happening?

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• How to lazy load a data structure (python)

  - by Anton Geraschenko

  I have some way of building a data structure (out of some file contents, say): def loadfile(FILE): return # some data structure created from the contents of FILE So I can do things like puppies = loadfile("puppies.csv") # wait for loadfile to work kitties = loadfile("kitties.csv") # wait some more print len(puppies) print puppies[32] In the above example, I wasted a bunch of time actually reading kitties.csv and creating a data structure that I never used. I'd like to avoid that waste without constantly checking if not kitties whenever I want to do something. I'd like to be able to do puppies = lazyload("puppies.csv") # instant kitties = lazyload("kitties.csv") # instant print len(puppies) # wait for loadfile print puppies[32] So if I don't ever try to do anything with kitties, loadfile("kitties.csv") never gets called. Is there some standard way to do this? After playing around with it for a bit, I produced the following solution, which appears to work correctly and is quite brief. Are there some alternatives? Are there drawbacks to using this approach that I should keep in mind? class lazyload: def __init__(self,FILE): self.FILE = FILE self.F = None def __getattr__(self,name): if not self.F: print "loading %s" % self.FILE self.F = loadfile(self.FILE) return object.__getattribute__(self.F, name) What might be even better is if something like this worked: class lazyload: def __init__(self,FILE): self.FILE = FILE def __getattr__(self,name): self = loadfile(self.FILE) # this never gets called again # since self is no longer a # lazyload instance return object.__getattribute__(self, name) But this doesn't work because self is local. It actually ends up calling loadfile every time you do anything.

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• Returning objects in php

  - by user220201

  I see similar questions asked but I seem to have problem with more basic stuff than were asked. How to declare a variable in php? My specific problem is I have a function that reads a DB table and returns the record (only one) as an object. class User{ public $uid; public $name; public $status; } function GetUserInfo($uid) { // Query DB $userObj = new User(); // convert the result into the User object. var_dump($userObj); return $userObj; } // In another file I call the above function. .... $newuser = GetUserInfo($uid); var_dump($newuser); What is the problem here, I cannot understand. Essentially the var_dump() in the function GetUserInfo() works fine. The var_dump() outside after the call to GetUserInfo() does not work. Thanks for any help. S

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• How would I associate a "Note" class to 4+ classes without creating lookup table for each associatio

  - by Gthompson83

  Im creating a project tasklist application. I have project, section, task, issue classes, and would like to use one class to be able to add simple notes to any object instance of those classes. The task, issue tables both use a standard identity field as a primary key. The section table has a two field primary key. The project table has a single int primary key defined by the user. Is there a way to associate the note class with each of these without using a seperate lookup table for each class? I'm not so sure my original idea is a decent way to implement this. I considered the following (each variable mapping to a field n the notes table. Private _NoteId As Integer Private _ProjectId As Integer Private _SectionId As Integer Private _SectionId2 As Integer Private _TaskId As Integer Private _IssueId As Integer Private _Note As String Private _UserId As Guid Then I would be able to write seperate methods (getProjectNotes, getTaskNotes) to get notes attached to each class. I started writing this a few weeks ago but got pulled away before i could finish. When revisiting this code today my first thought "this is retarded". Thoughts on drawbacks to this design?

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• transferring binary files between systems

  - by tim

  Hi guys I'm trying to transfer my files between 2 UNIX clusters, the data is pure numeric (vectors of double) in binary form. Unfortunately one of the systems is IBM ppc997 and the other is AMD Opteron, It seems the format of binary numbers in these systems are different. I have tried 3 ways till now: 1- Changed my files to ASCII format (i.e. saved a number at each line in a text file), sent them to the destination and changed them again to binary on the target system (they both are UNIX, no end of line character difference??!) 2- Sent pure binaries to the destination 3- used uuencode sent them to the destination and decoded them Unfortunately any of these methods does not work (my code in the destination system generates garbage, while it works on the first system, I'm 100% sure the code itself is portable). I don't know what else I can do? Do you have any idea? I'm not a professional, please don't use computer scientists terminology! And: my codes are in C, so by binary I mean a one to one mapping between memory and hard disk. Thanks

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• CodeModel help needed for right-hand singleton.getinstance() assignment.

  - by antarti

  I've been able to generate 99% of what I need with the CodeModel API, but I am stumped here... Using the various "directXX" methods does not add import statements to the generated code, and I can work without the "directXXX" type of methods except for one place in a generated class. Suppose I desire a generated method like: /** * Copies data from this Value-Obj instance, to the returned PERSON instance. * * @return PERSON * */ public PERSON mapVOToPERSON() throws MappingException { Mapper mapper = (com.blah.util.MapperSingleton.getMapperInstance()); return mapper.map(this, PERSON.class); } You can see the right hand of the Mapper assignment in parens. Emitting the entire package+class was the only way I could find to just declare "SomeSingleton.someMethod()" on the right hand side and have the generated code compile. Without the MapperSingleton being added to the object model, there is no import generated... Questions: 1) Is there a way to force an import to be generated? 2) How to declare an expression that gives me the right side of the Mapper assignment within the object model (so that an import of MapperSingleton gets generated. Any help appreciated...

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• Unable to add multiple textviews into linearLayout within a loop

  - by Adam

  for(int i=0;i<object.size();i++){ FeaturedSingleEvent event = (FeaturedSingleEvent) object.get(i); images.add(event.getImage()); LinearLayout info = new LinearLayout(this); info.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT)); TextView title = new TextView(this); title.setText(event.getTitle()); title.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT)); info.addView(title); TextView by = new TextView(this); by.setText(event.getBy() + " " + event.getBy_name()); by.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT)); info.addView(by); TextView summary = new TextView(this); summary.setText(event.getSummary()); summary.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT)); info.addView(summary); layout.addView(info); if(i == 0){ info.setVisibility(View.VISIBLE); }else{ info.setVisibility(View.GONE); } } I'm attempting to have multiple LinearLayouts, only one being visible at a time, to create a slideshow. In a for loop, I create the layouts with their textViews, and set only the first one to be visible. The problem is that only one TextView seems to be displaying, ie. if everything but summary is deleted, then summary will display. As of right now, only title will display, because i'm assuming it's the first one. I'm most likely doing it wrong, so any help would be appreciated.

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• How to re-enable the idle timer in ios once it has been disabled (to allow the display to sleep again)?

  - by lindon fox

  I have figured out how to stop an iOS device from going to sleep (see below), but I am having troubles undoing that setting. According to the Apple Documentation, it should just be changing the value of the idleTimerDisabled property. But when I test this, it does not work. This is how I am initially stopping the device from going to sleep: //need to switch off and on for it to work initially [UIApplication sharedApplication].idleTimerDisabled = NO; [UIApplication sharedApplication].idleTimerDisabled = YES; I would have thought that the following would do the trick: [UIApplication sharedApplication].idleTimerDisabled = NO; From the Apple Documentation: The default value of this property is NO. When most applications have no touches as user input for a short period, the system puts the device into a "sleep” state where the screen dims. This is done for the purposes of conserving power. However, applications that don't have user input except for the accelerometer—games, for instance—can, by setting this property to YES, disable the “idle timer” to avert system sleep. Important: You should set this property only if necessary and should be sure to reset it to NO when the need no longer exists. Most applications should let the system turn off the screen when the idle timer elapses. This includes audio applications. With appropriate use of Audio Session Services, playback and recording proceed uninterrupted when the screen turns off. The only applications that should disable the idle timer are mapping applications, games, or similar programs with sporadic user interaction. Has anyone come across this problem? I am testing on iOS6 and iOS5. Thanks in advance.

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• java + increasing performance and scalability

  - by varun

  Hi, below is the a code snippet, which returns the object of a class. now the object is basially comparing to some parameter in loop. my concern is what if there are thousands of objects in loop, in that case performance and scalability can be an issue. please suggest how to improve this code for performance part public Widget get(String name,int major,int minor,boolean exact) { Widget widgetToReturn = null; if(exact) { Widget w = new Widget(name, major, minor); // for loop using JDK 1.5 version for(Widget wid : set) { if((w.getName().equals(wid.getName())) && (wid.getVersion()).equals(w.getVersion())) { widgetToReturn = w; break; } } } else { Widget w = new Widget(name, major, minor); WidgetVersion widgetVersion = new WidgetVersion(major, minor); // for loop using JDK 1.5 version for(Widget wid : set) { WidgetVersion wv = wid.getVersion(); if((w.getName().equals(wid.getName())) && major == wv.getMajor() && WidgetVersion.isCompatibleAndNewer(wv, widgetVersion)) { widgetToReturn = wid; } else if((w.getName().equals(wid.getName())) && wv.equals(widgetVersion.getMajor(), widgetVersion.getMinor())) { widgetToReturn = w; } } } return widgetToReturn; }

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• Remove duplication's from my DropDownList

  - by user2976270

  In my controller i am returning list of my object with specific property: public ActionResult Index() { List<MyObject> list = db.MyObjects.Where(x => x.family == "Web").ToList(); ViewBag.Files = new SelectList(list, "Id", "protocol"); return View(); } This is my object: public class MyObject { public int id { get; set; } public string fileName { get; set; } public string browser { get; set; } public string protocol { get; set; } public string family { get; set; } } Index.cshtml: @Html.DropDownList("File", new SelectList(ViewBag.Files, "Id", "protocol_site"), "Select webmail site", new { style = "vertical-align:middle;" }) And i try to made 2 changes with no succeed: Remove all the duplication protocol from my DropDownListfor exapmle if i have 10 objects : 9 is doc protocol and 1 pdf i wand to see in my DropDownList only 2 items: DOC and PDF and not all the 10 items. Sort this DropDownList in alphabet order

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• NUll exception in filling a querystring by mocing framework

  - by user564101

  There is a simple controller that a querystring is read in constructor of it. public class ProductController : Controller { parivate string productName; public ProductController() { productName = Request.QueryString["productname"]; } public ActionResult Index() { ViewData["Message"] = productName; return View(); } } Also I have a function in unit test that create an instance of this Controller and I fill the querystring by a Mock object like below. [TestClass] public class ProductControllerTest { [TestMethod] public void test() { // Arrange var querystring = new System.Collections.Specialized.NameValueCollection { { "productname", "sampleproduct"} }; var mock = new Mock<ControllerContext>(); mock.SetupGet(p => p.HttpContext.Request.QueryString).Returns(querystring); var controller = new ProductController(); controller.ControllerContext = mock.Object; // Act var result = controller.Index() as ViewResult; // Assert Assert.AreEqual("Index", result.ViewName); } } Unfortunately Request.QueryString["productname"] is null in constructor of ProductController when I run test unit. Is ther any way to fill a querystrin by a mocking and get it in constructor of a control?

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• Class with property referenced with dll not serializing

  - by djerry

  Hey guys, I got this class TapiCall. It has 4 properties : 2 datetimes, 1 string and an object. The object is a class that's referenced by Atapi3.dll, so i cannot alter it. My class TapiCall looks like this : [DataContract] public class TapiCall { private DateTime start, end; private TCall call; private string status; [DataMember] public string Status { get { return status; } set { status = value; } } [DataMember] public TCall Call { get { return call; } set { call = value; } } [DataMember] public DateTime End { get { return end; } set { end = value; } } [DataMember] public DateTime Start { get { return start; } set { start = value; } } public TapiCall() { } public TapiCall(DateTime start, DateTime end, TCall call) { this.Start = start; this.End = end; this.Call = call; } } Now when i use my visual studio command line, to generate my proxy class, it generates an error. When i remove TapiCall from the method in my app, i can rebuild my proxy again, so i know [OperationContract] void StuurUpdatedCall(TapiCall tpCall); is causing the problem. My question now is can i Serialize a class that's referenced by a dll? Thanks in advance.

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• How to merge two icons together? (overlay one icon on top of another)

  - by demoncodemonkey

  I've got two 16x16 RGB/A .ICO icon files, each loaded into a separate System.Drawing.Icon object. How would you create a new Icon object containing the merge of the two icons (one overlaid on top of the other)? Edit: I probably wasn't too clear, I don't want to blend two images into each other, I want to overlay one icon on top of another. I should add that the icons already contain transparent parts and I do not need any transparent "blending" to make both icons visible. What I need is to overlay the non-transparent pixels of one icon over the top of another icon. The transparent pixels should let the background icon show through. For example, look at the stackoverflow icon. It has some areas that are grey and orange, and some areas that are totally transparent. Imagine you want to overlay the SO icon on top of the Firefox icon. You would see the greys and oranges of the SO icon in full colour, and where the SO icon is transparent, you would see those parts of the Firefox icon.

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• XML digital signature interface

  - by yeekang

  I am trying to call a WebService and it requires me to prepare an XML digital signature interface. I came across this website and it shows how to sign an XML document. My problem now is that I do not create the XML document myself. My code is as follows: string myResult; GenericWS.ServicesService a = new GenericWS.ServicesService(); GenericWS.Service2 b = new GenericWS.Service2(); b.Something = "3"; X509Certificate cert = X509Certificate.CreateFromCertFile("C:\\somepath\\somecert.cer"); a.ClientCertificates.Add(cert); ServicePointManager.ServerCertificateValidationCallback = delegate (object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { return true; }; myResult= a.WSRequest(b).WSReturnValue.ToString(); Label1.Text = myResult; Basically, the WSRequest() will generate the body of the SOAP message. However, in order to sign the SOAP message, I need to pass in the XML file that needs to be signed. I tried to serialize the object and cast it as XML and pass it into the signature interface but I do not have another method that I can invoke to call the webmethod. Is there any other solution?

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• Dynamically change embedded video src in IE/Chrome (works in Firefox)

  - by macca1

  I'm trying to dynamically change an embedded video on a page. It's working in Firefox but for some reason it's not working in IE and Chrome (strange combination). Here's the HTML: <object id="viewer" width="575" height="344"> <param name="wmode" value="transparent" /> <param name="movie" value="http://www.youtube.com/v/Lmn94kn08Lw&hl=en&fs=1&color1=0x006699&color2=0x54abd6&rel=0" /> <param name="allowFullScreen" value="true" /> <embed id="embeddedPlayer" src="http://www.youtube.com/v/Lmn94kn08Lw&hl=en&fs=1&color1=0x006699&color2=0x54abd6&rel=0" type="application/x-shockwave-flash" allowfullscreen="true" width="575" height="344" wmode="transparent"></embed> </object> And here's my javascript code. A link is clicked to change the video: $("#video a").click( function() { var videoAddress = $(this).attr("href"); $("#embeddedPlayer").attr("src", videoAddress); return false; // stop the default link so it just reloads in the video player } ); Like I said the videos are changing perfectly in Firefox but in IE and Chrome nothing happens. Any ideas?

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• BufferedImage & ColorModel in Java

  - by spol

  I am using a image processing library in java to manipulate images.The first step I do is I read an image and create a java.awt.Image.BufferedImage object. I do it in this way, BufferedImage sourceImage = ImageIO.read( new File( filePath ) ); The above code creates a BufferedImage ojbect with a DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0. This is what happens when I run the above code on my macbook. But when I run this same code on a linux machine (hosted server), this creates a BufferedImage object with ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@c39a20 transparency = 1 has alpha = false isAlphaPre = false. And I use the same jpg image in both the cases. I don't know why the color model on the same image is different when run on mac and linux. The colormodel for mac has 4 components and the colormodel for linux has 3 components.There is a problem arising because of this, the image processing library that I use always assumes that there are always 4 components in the colormodel of the image passed, and it throws array out of bounds exception when run on linux box. But on macbook, it runs fine. I am not sure if I am doing something wrong or there is a problem with the library. Please let me know your thoughts. Also ask me any questions if I am not making sense!

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• Reflection and Generics get value of property

  - by GigaPr

  Hi i am trying to implement a generic method which allows to output csv file public static void WriteToCsv<T>(List<T> list) where T : new() { const string attachment = "attachment; filename=PersonList.csv"; HttpContext.Current.Response.Clear(); HttpContext.Current.Response.ClearHeaders(); HttpContext.Current.Response.ClearContent(); HttpContext.Current.Response.AddHeader("content-disposition", attachment); HttpContext.Current.Response.ContentType = "text/csv"; HttpContext.Current.Response.AddHeader("Pragma", "public"); bool isFirstRow = true; foreach (T item in list) { //Get public properties PropertyInfo[] propertyInfo = item.GetType().GetProperties(); while (isFirstRow) { WriteColumnName(propertyInfo); isFirstRow = false; } Type type = typeof (T); StringBuilder stringBuilder = new StringBuilder(); foreach (PropertyInfo info in propertyInfo) { //string value ???? I am trying to get the value of the property info for the item object } HttpContext.Current.Response.Write(stringBuilder.ToString()); HttpContext.Current.Response.Write(Environment.NewLine); } HttpContext.Current.Response.End(); } but I am not able to get the value of the object's property Any suggestion? Thanks

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• Mixing stored procedures and ORM

  - by Jason

  The company I work for develops a large application which is almost entirely based on stored procedures. We use classic ASP and SQL Server and the major part of the business logic is contained inside those stored procedures. For example, (I know, this is bad...) a single stored procedure can be used for different purposes (insert, update, delete, make some calculations, ...). Most of the time, a stored procedure is used for operations on related tables, but this is not always the case. We are planning to move to ASP.NET in a near future. I have read a lot of posts on StackOverflow recommending that I move the business logic outside the database. The thing is, I have tried to convince the people who takes the decisions at our company and there is nothing I can do to change their mind. Since I want to be able to use the advantages of object-oriented programming, I want to map the tables to actual classes. So far, my solution is to use an ORM (Entity Framework 4 or nHibernate) to avoid mapping the objects manually (mostly to retrieve the data) and use some kind of Data Access Layer to call the existing stored procedures (for saving). I want your advice on this. Do you think it is a good solution? Any ideas?

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• How to translate the fields of a database model?

  - by Tõnis M

  I have some tables/models in a web app that will have multilingual content. For example a university, with it's description in a default language(english) and the user wants he can see the same information in another language( if the object has it's fields translated). If there were only a few languages then I would just add fields like name_en and name_de and so on, but the number of languages isn't fixed, so that' would create a mess. I could also just create a new object with the translated data but then foreign keys wouldn't work, and only some of the fields can be translated so that would create duplicate data. Storing the translations in a file and using gettext or something similar is also not an option since the objects fields can be translated by the website user, not only developers/admins. What would be the best way to design/architect such a database? Searching from the translated data should also be not too complex - as it should not require creating complex joins which would make the queries slower I'm using PostgreSQL and Ruby of Rails but I'm not looking for a technical solution but for a general idea how to design it.

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• Any techniques to interrupt, kill, or otherwise unwind (releasing synchronization locks) a single de

  - by gojomo

  I have a long-running process where, due to a bug, a trivial/expendable thread is deadlocked with a thread which I would like to continue, so that it can perform some final reporting that would be hard to reproduce in another way. Of course, fixing the bug for future runs is the proper ultimate resolution. Of course, any such forced interrupt/kill/stop of any thread is inherently unsafe and likely to cause other unpredictable inconsistencies. (I'm familiar with all the standard warnings and the reasons for them.) But still, since the only alternative is to kill the JVM process and go through a more lengthy procedure which would result in a less-complete final report, messy/deprecated/dangerous/risky/one-time techniques are exactly what I'd like to try. The JVM is Sun's 1.6.0_16 64-bit on Ubuntu, and the expendable thread is waiting-to-lock an object monitor. Can an OS signal directed to an exact thread create an InterruptedException in the expendable thread? Could attaching with gdb, and directly tampering with JVM data or calling JVM procedures allow a forced-release of the object monitor held by the expendable thread? Would a Thread.interrupt() from another thread generate a InterruptedException from the waiting-to-lock frame? (With some effort, I can inject an arbitrary beanshell script into the running system.) Can the deprecated Thread.stop() be sent via JMX or any other remote-injection method? Any ideas appreciated, the more 'dangerous', the better! And, if your suggestion has worked in personal experience in a similar situation, the best!

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• ThreadExceptionEventHandler and invoking delegates

  - by QmunkE

  If I assign a ThreadExceptionEventHandler to Application.ThreadException, why when I invoke a delegate method using a control on the main application thread are any exceptions thrown by that delegate not triggering the event handler? i.e. static void Main() { ... Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException); Application.Run(new Form1()); } static void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e) { Console.Error.Write("A thread exception occurred!"); } ... private void Form1_Load(object sender, EventArgs e) { Thread syncThread = new Thread(new ThreadStart(this.ThrowException)); syncThread.Start(); } private void ThrowException() { button1.Invoke(new MethodInvoker(delegate { // Not handled by ThreadExceptionEventHandler? throw new Exception(); })); } The context on this is that I have a background thread started from a form which is throwing an unhandled exception which terminates the application. I know this thread is going to be unreliable since it is network connectivity reliant and so subject to being terminated at any point, but I'm just interested as to why this scenario doesn't play out as I expect?

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• How do software events work internally?

  - by Duddle

  Hello! I am a student of Computer Science and have learned many of the basic concepts of what is going on "under the hood" while a computer program is running. But recently I realized that I do not understand how software events work efficiently. In hardware, this is easy: instead of the processor "busy waiting" to see if something happened, the component sends an interrupt request. But how does this work in, for example, a mouse-over event? My guess is as follows: if the mouse sends a signal ("moved"), the operating system calculates its new position p, then checks what program is being drawn on the screen, tells that program position p, then the program itself checks what object is at p, checks if any event handlers are associated with said object and finally fires them. That sounds terribly inefficient to me, since a tiny mouse movement equates to a lot of cpu context switches (which I learned are relatively expensive). And then there are dozens of background applications that may want to do stuff of their own as well. Where is my intuition failing me? I realize that even "slow" 500MHz processors do 500 million operations per second, but still it seems too much work for such a simple event. Thanks in advance!

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• Can this line of code really throw an IndexOutOfRange exception?

  - by Jonathan M

  I am getting an IndexOutOfRange exception on the following line of code: var searchLastCriteria = (SearchCriteria)Session.GetSafely(WebConstants.KeyNames.SEARCH_LAST_CRITERIA); I'll explain the above here: SearchCriteria is an Enum with only two values Session is the HttpSessionState GetSafely is an extension method that looks like this: public static object GetSafely(this HttpSessionState source, string key) { try { return source[key]; } catch (Exception exc) { log.Info(exc); return null; } } WebConstants.KeyNames.SEARCH_LAST_CRITERIA is simply a constant I've tried everything to replicate this error, but I cannot reproduce it. I am beginning to think the stack trace is wrong. I thought perhaps the exception was actually coming from the GetSafely call, but it is swallowing the exceptions, so that can't be the case, and even if it was, it should show up in the stack trace. Is there anything in the line of code above that could possible throw an IndexOutOfRange exception? I know the line will throw an NullReferenceException if GetSafely returns null, and it will also throw an InvalidCastException if it returns anything that cannot be cast to SearchCriteria, but an IndexOutOfRange exception? I'm scratching my head here. Here is the stack trace: $LOG--> 2010-06-11 07:01:33,814 [ERROR] SERVERA (14) Web.Global - Index was outside the bounds of the array. System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.IndexOutOfRangeException: Index was outside the bounds of the array. at IterateSearchResult(Boolean next) in C:\Projects\Web\UserControls\AccountHeader.ascx.cs:line 242 at nextAccountLink_Click(Object sender, EventArgs e) in C:\Projects\Web\UserControls\AccountHeader.ascx.cs:line 232

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