Search Results

Search found 29498 results on 1180 pages for 'object destruction'.

Page 568/1180 | < Previous Page | 564 565 566 567 568 569 570 571 572 573 574 575  | Next Page >

  • Can I prevent a Linux user space pthread yielding in critical code?

    - by KermitG
    I am working on an user space app for an embedded Linux project using the 2.6.24.3 kernel. My app passes data between two file nodes by creating 2 pthreads that each sleep until a asynchronous IO operation completes at which point it wakes and runs a completion handler. The completion handlers need to keep track of how many transfers are pending and maintain a handful of linked lists that one thread will add to and the other will remove. // sleep here until events arrive or time out expires for(;;) { no_of_events = io_getevents(ctx, 1, num_events, events, &timeout); // Process each aio event that has completed or thrown an error for (i=0; i<no_of_events; i++) { // Get pointer to completion handler io_complete = (io_callback_t) events[i].data; // Get pointer to data object iocb = (struct iocb *) events[i].obj; // Call completion handler and pass it the data object io_complete(ctx, iocb, events[i].res, events[i].res2); } } My question is this... Is there a simple way I can prevent the currently active thread from yielding whilst it runs the completion handler rather than going down the mutex/spin lock route? Or failing that can Linux be configured to prevent yielding a pthread when a mutex/spin lock is held?

    Read the article

  • ASP.NET MVC (VB) error when publishing to test server

    - by Colin
    I have an ASP.NET MVC project that works fine on my local machine (no build errors, server errors or anything). However, when I publish the project to a test server, I get an "Object reference not set to an instance of an object" error on a For Each I have in my view. I have a function within a model that returns a DataRowCollection. I'm calling that function in my controller and passing the DataRowCollection to my View, which then iterates over the rows and displays the necessary information: In the Controller I have: Function Index() As ActionResult Dim MyModel As New Model ViewData("MyDataRowCollection") = MyModel.GetDataRowCollection() Return View() End Function And then in the View, which is throwing the error: <%@ Page Language="VB" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %> <asp:Content ID="indexTitle" ContentPlaceHolderID="TitleContent" runat="server"> My Page Title </asp:Content> <asp:Content ID="indexContent" ContentPlaceHolderID="MainContent" runat="server"> <% For Each MyDataRow In ViewData("MyDataRowCollection") ' do stuff with each MyDataRow Next %> I'm pretty new to ASP.NET MVC so I'm sure there might be a better way to do what I'm doing (I'd be happy to hear if there is), but my main concern is why this works fine on my local machine but throws an error on the For Each on the test server? Please let me know if I can clarify any of the above, and thanks in advance for any information.

    Read the article

  • scroll bar problems in java Layered Panes

    - by vondip
    Hi all, I've been trying to build this small java app. I find it very difficult to design UI in java, tasks that seem very simple become complicated and all these strange misbehaviors occur. In my app I've created a JLayeredPane which contains two layers. One on top on the other, They both contain scrollbars. Here's an explanation of the two layers: Layer 1: A very big image inside something similar to a scrollpane. The image is scrollable. Layer 2: A graphics2d object, this object draws an image. Once the image reaches a certain length, the layer gets a scrollpane that advances with the drawing with time. I'd like to connect both layers. I want layer two to update the scrollbar on layer 1. Meaning that once it reaches a certain length, both scrollbars will advance together. When I try doing that, the two scroll bars really do advance, but ( ! ) this strange flickering occurs. I don't understand what is the reason for the flickering. Is there any other way to implement this in a simple manner? I must have the second layer on top of the first one (drawing on top of image) since I cannot open a special post for thanking the wonderful people of this forum, I'll do it here. Thank you, you are great help. I hope this problem is solvable as well.

    Read the article

  • Message Handlers and the WeakReference issue

    - by user1058647
    The following message Handler works fine receiving messages from my service... private Handler handler = new Handler() { public void handleMessage(Message message) { Object path = message.obj; if (message.arg1 == 5 && path != null) //5 means its a single mapleg to plot on the map { String myString = (String) message.obj; Gson gson = new Gson(); MapPlot mapleg = gson.fromJson(myString, MapPlot.class); myMapView.getOverlays().add(new DirectionPathOverlay(mapleg.fromPoint, mapleg.toPoint)); mc.animateTo(mapleg.toPoint); } else { if (message.arg1 == RESULT_OK && path != null) { Toast.makeText(PSActivity.this, "Service Started" + path.toString(), Toast.LENGTH_LONG).show(); } else { Toast.makeText(PSActivity.this,"Service error" + String.valueOf(message.arg1), Toast.LENGTH_LONG).show(); } } }; }; However, even though it tests out alright in the AVD (I'm feeding it a large KML file via DDMS) the "object path = message.obj;" line has a WARNING saying "this Handler class should be static else leaks might occur". But if I say "static Handler handler = new Handler()" it won't compile complaining that I "cannot make a static reference to a non-static field myMapView. If I can't make such references, I can't do anything useful. This led me into several hours of googling around on this issue and learning more about weakReferences than I ever wanted to know. The often found reccomendation I find is that I should replace... private Handler handler = new Handler() with static class handler extends Handler { private final WeakReference<PSActivity> mTarget; handler(PSActivity target) { mTarget = new WeakReference<PSActivity>(target); } But this won't compile still complaining that I can't make a static reference to a non-dtatic field. So, my question a week or to ago was "how can I write a message handler for android so my service can send data to my activity. Even though I have working code, the question still stands with the suffix "without leaking memory". Thanks, Gary

    Read the article

  • Cannont Update control in WPF custom control

    - by Fazi
    I have created a custom control which holds a button in it. The button is styled, so as to hold a grid with two rows, an image in the first and a TextBlock in the second. I have written an Event Handler for the custom control. When the mouse enters the path of the object the MouseEnter event fires, where I try to change the TextBlock's FontSize and Foreground color, however the control does not update. In contrast, I have tried to modify an regular TextBlock's(not part a custom control and controltemplate) properties, and they update correctly, on the fly. What am I missing here?? Here is the code for the event handler: private void ThemeButton_MouseEnter(object sender, MouseEventArgs e) { InitializeProperties(); TextElement.FontSize = 16; TextElement.Text = "new text"; TextElement.Foreground = Brushes.Red; TextBlock element = MainWindow.FindChild<TextBlock>(MainWindow.StartWindow, "textField"); element.Text = "new text for regular textblock"; element.Foreground = Brushes.Red; } InitializeProperties is a methid that initializes TextElement(typeof TextBlock) and ImageElement(typeof Image) properties. They are not null. The properties are just regular .NET properties.

    Read the article

  • LINQ to SQL: Reusable expression for property?

    - by coenvdwel
    Pardon me for being unable to phrase the title more exact. Basically, I have three LINQ objects linked to tables. One is Product, the other is Company and the last is a mapping table Mapping to store what Company sells which products and by which ID this Company refers to this Product. I am now retrieving a list of products as follows: var options = new DataLoadOptions(); options.LoadWith<Product>(p => p.Mappings); context.LoadOptions = options; var products = ( from p in context.Products select new { ProductID = p.ProductID, //BackendProductID = p.BackendProductID, BackendProductID = (p.Mappings.Count == 0) ? "None" : (p.Mappings.Count > 1) ? "Multiple" : p.Mappings.First().BackendProductID, Description = p.Description } ).ToList(); This does a single query retrieving the information I want. But I want to be able to move the logic behind the BackendProductID into the LINQ object so I can use the commented line instead of the annoyingly nested ternary operator statements for neatness and re-usability. So I added the following property to the Product object: public string BackendProductID { get { if (Mappings.Count == 0) return "None"; if (Mappings.Count > 1) return "Multiple"; return Mappings.First().BackendProductID; } } The list is still the same, but it now does a query for every single Product to get it's BackendProductID. The code is neater and re-usable, but the performance now is terrible. What I need is some kind of Expression or Delegate but I couldn't get my head around writing one. It always ended up querying for every single product, still. Any help would be appreciated!

    Read the article

  • Save Xml in an Excel cell value causes ComException

    - by mas_oz2k1
    I am trying to save an object (Class1) as string in a cell value. My issue is that from time to time I have a ComException: HRESULT: 0x8007000E (E_OUTOFMEMORY) (It is kind of random but I have not identified any particular pattern yet) when I write the value into a cell. Any ideas will be welcome For illustration purposes: Let Class1 be the class to be converted to an Xml string. (Notice that I removed the xml declaration at the start of the string to avoid having the preamble present- non printable character) <Class1 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" <ElementID HL690375</ElementID </Class1" Class1 myClass = new Class1(); this class is converted to a string s. s= ConvertObjectToXmlString(myClass); then s is assigned to a cell Range r = Application.ActiveCell; r.Value2 = s; Note: (1) If the string is too big, I limit it to 32000 chars and split the string in chunks of 32000 chars and save the chunks in multiple cells. (2) I do not to quote the string before adding to a cell. Do I need to? If so how it can be done? (3) All object contents are English. (4) C# code sample will be great but VB.net code is OK.

    Read the article

  • Can't seem to get .Union to work (merging 2 array's together, exclude duplicates)

    - by D. Veloper
    I want to combine two array's, excluding duplicates. I am using a custom class: public class ArcContact : IEquatable<ArcContact> { public String Text; public Boolean Equals(ArcContact other) { if (Object.ReferenceEquals(other, null)) return false; if (Object.ReferenceEquals(this, other)) return true; return Text.Equals(other.Text); } public override Int32 GetHashCode() { return Text == null ? 0 : Text.GetHashCode(); } } I implemented and the needed IEquatable interface as mentioned in this msdn section. I only want to check the Text property of the ArcContact class and make sure an Array of ArcContact have an unique Text. Here I pasted the code that I use, as you can see I have method with two parameters, array's to combine and below that the code I got from the previous mentioned msdn section. internal static class ArcBizz { internal static ArcContact[] MergeDuplicateContacts(ArcContact[] contacts1, ArcContact[] contacts2) { return (ArcContact[])contacts1.Union(contacts2); } internal static IEnumerable<T> Union<T>(this IEnumerable<T> a, IEnumerable<T> b); } What am I doing wrong?

    Read the article

  • Can I change the binding source to another source in XAML?

    - by No hay Problema
    Hi guys, I want to do a very simple thing, can you point me on the right direction? I want to change the source in XAML to another object source, let me put you an example: I have a Listview, bound to a "Model A", it has many properties, but one is called "Total". This property is not shown on the View Each ListviewItem has its own source (ItemsSource), BUT, one of the fields should show "Total" from "Model A" Caveat: I am implementing MVVM, so the "Model A" is assigned as a VM DataSource, XAML knows nothing about it. So, in my perfect world the XAML should look like this: <GridViewColumn Header="Total" Width="150"> <GridViewColumn.CellTemplate> <DataTemplate> <Label Content="{Binding Source=<The source of LISTVIEW> Path=Total}"/> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> I have tried RelativeSource but that points me to the XAML object, I want the source of it, is it possible? Thanks

    Read the article

  • XmlSerializer 'forgetting' my namespace

    - by Michel
    Hi, i have to create an XML file with all the elements prefixed, like this: <ps:Request num="123" xmlns:ps="www.ladieda.com"> <ps:ClientId>5566</ps:ClientId> <ps:Request> When i serialize my object, c# is smart and does this: <Request num="123" xmlns="www.ladieda.com"> <ClientId>5566</ClientId> <Request> That is good, because the ps: is not necessary. But is there a way to force C# to serialize all the prefixes? My serialize code is this (for incoming object pObject): String XmlizedString = null; MemoryStream memoryStream = new MemoryStream(); XmlSerializer xs = new XmlSerializer(pObject.GetType()); XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8); xs.Serialize(xmlTextWriter, pObject); memoryStream = (MemoryStream)xmlTextWriter.BaseStream; XmlizedString = UTF8ByteArrayToString(memoryStream.ToArray()); return XmlizedString; private String UTF8ByteArrayToString(Byte[] characters) { UTF8Encoding encoding = new UTF8Encoding(); String constructedString = encoding.GetString(characters); return (constructedString); }

    Read the article

  • Why are Facebook Likes Insisting on using Wrong Product Image...?

    - by Joan Kent
    Firstly, I'm not a web developer so please be patient. I have read the other posts but I think i have everything covered. My website http://www.joaniesgifts.co.uk includes the like button on the product pages. However, I've found that certain product pages are using the incorrect image when a user likes the page. For example - http://www.joaniesgifts.co.uk/terramundi-money-pots/terramundi-money-pot-holiday-fund I think this may have been down to an original incorrect setup which is now corrected. However, the problem remains... The only thing I have to go on :- if i use the facebook url linter (developers.facebook.com/tools/debug) on the above product page, I receive the following error :- Object at URL 'http://www.joaniesgifts.co.uk/terramundi-money-pot-holiday-fund' of type '213689662010141:product' is invalid because the domain 'www.joaniesgifts.co.uk' is not allowed for the application id '213689662010141' which owns the specified object type. If you are the owner of this application, you can verify your configured 'Site Domain' at developers.facebook.com/apps/213689662010141. (I have verified my site's domain) Everything else appears fine except it is also showing the wrong image!! However, under Raw Open Graph Document Information it has the correct link! If I then click graph api - graph.facebook.com/10150450766583352 it again shows the wrong image was linked! I've no idea what else to do - can you help me? Kind Regards, Joan PS Graph API shows the incorrect image after a scrape only minutes ago { "url": "http://www.joaniesgifts.co.uk/terramundi-money-pot-holiday-fund", "type": "website", "title": "Terramundi Money Pot - Holiday Fund", "image": [ { "url": "http://www.joaniesgifts.co.uk/index.php?route=product\u00252Fproduct\u00252Fcaptcha" } ], "updated_time": "2011-11-11T18:54:38+0000", "id": "10150450766583352" }

    Read the article

  • Jtable live updating problem

    - by Fishinastorm
    Hi all, I'm trying to display a jtable in a pop up Jframe and am running into some problems. What i'am trying to do is as follows: catch a button action event in the main frame and display a pop up frame with a jtable populated with some data. The problem i have is that the jtable is populated with metadata i receive from a website and if i'm receiving many records, then the jtable is not displayed until all the records(metadata) is received from the website. I would like to change it such that as soon as the button event is detected in the main frame, I display the pop up frame along with the jtable and insert/update rows "as and when i receive the data from the website". In another words, i want to display the table and have the records appearing one at a time rather than displaying the jtable only after i receive all records.Below is how i'm trying to do it (but in vain :( ): ......... //add the table to the popup frame when application is started, but don't display the frame `until button action is //detected` extraInfoFrame.add(tblMetadata); extraInfoFrame.setVisible(false); //handle code for button press; display the popup private void butMetadataActionPerformed(java.awt.event.ActionEvent evt) { extraInfoFrame.pack(); extraInfoFrame.toFront(); //frame.setSize(350, 250); extraInfoFrame.setVisible(true); //retrieve rows data for the table for(int i=0;i<len;i++){ Object[] data=new Object[4];data=getMetadata(); //get model and insert row ((javax.swing.table.DefaultTableModel)tblMetadata.getModel()).insertRow(i,data); //tried something to notify the view abt change in table data ((javax.swing.table.DefaultTableModel)tblMetadata.getModel()).fireTableRowsInserted(0, 0); tblMetadata.revalidate(); tblMetadata.repaint(); } } Have been racking my head to try and figure something out. A sample example would be greatly appreciated.

    Read the article

  • JAXB Annotated class - setting of a variable which is not an element

    - by sswdeveloper
    I have a JAXB annotated class say @XmlRootElement(namespace = "http://www.abc.com/customer") Class Customer{ @XmlElement(namespace = "http://www.abc.com/customer") private String Name; @XmlElement(namespace = "http://www.abc.com/customer") private String Address; @XmlTransient private HashSet set = new HashSet(); public String getName(){ return Name; } public void setName(String name){ this.Name = name; set.add("Name"); } public String getAddress(){ return Address; } public void setAddress(String address){ this.Address = address; set.add("Address"); } public void getSet(){ return set; } I have a XML of the form <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <Customer xmlns="http://www.abc.com/customer" > <Name>Ralph</Name> <Address>Newton Street</Address> </Customer> I use JAXB unmarshalling to get the object representation of the XML input. The values for Name and Address are set correctly. However the value of set gets lost(since it is @XMLTransient it gets ignored) Is there any way of ensuring that it is still set in the object which has been unmarshalled? Some other annotation which I can use?

    Read the article

  • WCF data services (OData), query with inheritance limitation?

    - by Mathieu Hétu
    Project: WCF Data service using internally EF4 CTP5 Code-First approach. I configured entities with inheritance (TPH). See previous question on this topic: Previous question about multiple entities- same table The mapping works well, and unit test over EF4 confirms that queries runs smoothly. My entities looks like this: ContactBase (abstract) Customer (inherits from ContactBase), this entity has also several Navigation properties toward other entities Resource (inherits from ContactBase) I have configured a discriminator, so both Customer and Resource map to the same table. Again, everythings works fine on the Ef4 point of view (unit tests all greens!) However, when exposing this DBContext over WCF Data services, I get: - CustomerBases sets exposed (Customers and Resources sets seems hidden, is it by design?) - When I query over Odata on Customers, I get this error: Navigation Properties are not supported on derived entity types. Entity Set 'ContactBases' has a instance of type 'CodeFirstNamespace.Customer', which is an derived entity type and has navigation properties. Please remove all the navigation properties from type 'CodeFirstNamespace.Customer'. Stacktrace: at System.Data.Services.Serializers.SyndicationSerializer.WriteObjectProperties(IExpandedResult expanded, Object customObject, ResourceType resourceType, Uri absoluteUri, String relativeUri, SyndicationItem item, DictionaryContent content, EpmSourcePathSegment currentSourceRoot) at System.Data.Services.Serializers.SyndicationSerializer.WriteEntryElement(IExpandedResult expanded, Object element, ResourceType expectedType, Uri absoluteUri, String relativeUri, SyndicationItem target) at System.Data.Services.Serializers.SyndicationSerializer.<DeferredFeedItems>d__b.MoveNext() at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteItems(XmlWriter writer, IEnumerable`1 items, Uri feedBaseUri) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeedTo(XmlWriter writer, SyndicationFeed feed, Boolean isSourceFeed) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeed(XmlWriter writer) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteTo(XmlWriter writer) at System.Data.Services.Serializers.SyndicationSerializer.WriteTopLevelElements(IExpandedResult expanded, IEnumerator elements, Boolean hasMoved) at System.Data.Services.Serializers.Serializer.WriteRequest(IEnumerator queryResults, Boolean hasMoved) at System.Data.Services.ResponseBodyWriter.Write(Stream stream) Seems like a limitation of WCF Data services... is it? Not much documentation can be found on the web about WCF Data services (OData) and inheritance specifications. How can I overpass this exception? I need these navigation properties on derived entities, and inheritance seems the only way to provide mapping of 2 entites on the same table with Ef4 CTP5... Any thoughts?

    Read the article

  • Where does "new" fit in the flex creation cycle?

    - by deux11
    In the following code, the call to myChild.bar() results in an exception because myChild is null. myParent is a valid object. What I don't understand is why myChild has not been created yet. I have read the following document related to object creation sequence, but I am unsure how "new" is related: http://livedocs.adobe.com/flex/3/html/help.html?content=layoutperformance_03.html Any help is appreciated! // Main.mxml <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="created()"> <mx:Script> <![CDATA[ public var myParent:Parent = new Parent(); public function created():void { myParent.foo(); } ]]> </mx:Script> </mx:Application> // Parent.mxml <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" xmlns="*"> <mx:Script> <![CDATA[ public function foo():void { myChild.bar(); } ]]> </mx:Script> <Child id="myChild"/> </mx:Canvas> // Child.mxml <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Script> <![CDATA[ public function bar():void { trace("Hello World"); } ]]> </mx:Script> </mx:Canvas>

    Read the article

  • How to maintain ComboBox.SelectedItem reference when DataSource is resorted?

    - by Dave
    This really seems like a bug to me, but perhaps some databinding gurus can enlighten me? (My WinForms databinding knowledge is quite limited.) I have a ComboBox bound to a sorted DataView. When the properties of the items in the DataView change such that items are resorted, the SelectedItem in my ComboBox does not keep in-sync. It seems to point to someplace completely random. Is this a bug, or am I missing something in my databinding? Here is a sample application that reproduces the problem. All you need is a Button and a ComboBox: public partial class Form1 : Form { private DataTable myData; public Form1() { this.InitializeComponent(); this.myData = new DataTable(); this.myData.Columns.Add("ID", typeof(int)); this.myData.Columns.Add("Name", typeof(string)); this.myData.Columns.Add("LastModified", typeof(DateTime)); this.myData.Rows.Add(1, "first", DateTime.Now.AddMinutes(-2)); this.myData.Rows.Add(2, "second", DateTime.Now.AddMinutes(-1)); this.myData.Rows.Add(3, "third", DateTime.Now); this.myData.DefaultView.Sort = "LastModified DESC"; this.comboBox1.DataSource = this.myData.DefaultView; this.comboBox1.ValueMember = "ID"; this.comboBox1.DisplayMember = "Name"; } private void saveStuffButton_Click(object sender, EventArgs e) { DataRowView preUpdateSelectedItem = (DataRowView)this.comboBox1.SelectedItem; // OUTPUT: SelectedIndex = 0; SelectedItem.Name = third Debug.WriteLine(string.Format("SelectedIndex = {0:N0}; SelectedItem.Name = {1}", this.comboBox1.SelectedIndex, preUpdateSelectedItem["Name"])); this.myData.Rows[0]["LastModified"] = DateTime.Now; DataRowView postUpdateSelectedItem = (DataRowView)this.comboBox1.SelectedItem; // OUTPUT: SelectedIndex = 2; SelectedItem.Name = second Debug.WriteLine(string.Format("SelectedIndex = {0:N0}; SelectedItem.Name = {1}", this.comboBox1.SelectedIndex, postUpdateSelectedItem["Name"])); // FAIL! Debug.Assert(object.ReferenceEquals(preUpdateSelectedItem, postUpdateSelectedItem)); } }

    Read the article

  • Can't add to NSMutableArray from SecondaryView

    - by Antonio
    Hi guys, I've searched and read and still haven't found a concrete answer. Brief: I have an application where I declare an NSMutableArray in my AppDelegate to synthesize when the application loads. (code below). I have a SecondaryViewController call this function, and I have it output a string to let me know what the array size is. Every time I run it, it executes but it does not add any objects to the array. How do I fix this? AppDelegate.h file #import <UIKit/UIKit.h> @class arrayTestViewController; @interface arrayTestAppDelegate : NSObject <UIApplicationDelegate> { UIWindow *window; arrayTestViewController *viewController; NSMutableArray *myArray3; } @property (nonatomic, retain) NSMutableArray *myArray3; @property (nonatomic, retain) IBOutlet UIWindow *window; @property (nonatomic, retain) IBOutlet arrayTestViewController *viewController; -(void)addToArray3; @end AppDelegate.m file #import "arrayTestAppDelegate.h" #import "arrayTestViewController.h" @implementation arrayTestAppDelegate @synthesize window; @synthesize viewController; @synthesize myArray3; #pragma mark - #pragma mark Application lifecycle - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { myArray3 = [[NSMutableArray alloc] init]; // Override point for customization after application launch. // Add the view controller's view to the window and display. [window addSubview:viewController.view]; [window makeKeyAndVisible]; return YES; } -(void)addToArray3{ NSLog(@"Array Count: %d", [myArray3 count]); [myArray3 addObject:@"Test"]; NSLog(@"Array triggered from SecondViewController"); NSLog(@"Array Count: %d", [myArray3 count]); } SecondViewController.m file #import "SecondViewController.h" #import "arrayTestAppDelegate.h" @implementation SecondViewController -(IBAction)addToArray{ arrayTestAppDelegate *object = [[arrayTestAppDelegate alloc] init]; [object addToArray3]; }

    Read the article

  • How to improve multi-threaded access to Cache (custom implementation)

    - by Andy
    I have a custom Cache implementation, which allows to cache TCacheable<TKey> descendants using LRU (Least Recently Used) cache replacement algorithm. Every time an element is accessed, it is bubbled up to the top of the LRU queue using the following synchronized function: // a single instance is created to handle all TCacheable<T> elements public class Cache() { private object syncQueue = new object(); private void topQueue(TCacheable<T> el) { lock (syncQueue) if (newest != el) { if (el.elder != null) el.elder.newer = el.newer; if (el.newer != null) el.newer.elder = el.elder; if (oldest == el) oldest = el.newer; if (oldest == null) oldest = el; if (newest != null) newest.newer = el; el.newer = null; el.elder = newest; newest = el; } } } The bottleneck in this function is the lock() operator, which limits cache access to just one thread at a time. Question: Is it possible to get rid of lock(syncQueue) in this function while still preserving the queue integrity?

    Read the article

  • Questions regarding detouring by modifying the virtual table

    - by Elliott Darfink
    I've been practicing detours using the same approach as Microsoft Detours (replace the first five bytes with a jmp and an address). More recently I've been reading about detouring by modifying the virtual table. I would appreciate if someone could shed some light on the subject by mentioning a few pros and cons with this method compared to the one previously mentioned! I'd also like to ask about patched vtables and objects on the stack. Consider the following situation: // Class definition struct Foo { virtual void Call(void) { std::cout << "FooCall\n"; } }; // If it's GCC, 'this' is passed as the first parameter void MyCall(Foo * object) { std::cout << "MyCall\n"; } // In some function Foo * foo = new Foo; // Allocated on the heap Foo foo2; // Created on the stack // Arguments: void ** vtable, uint offset, void * replacement PatchVTable(*reinterpret_cast<void***>(foo), 0, MyCall); // Call the methods foo->Call(); // Outputs: 'MyCall' foo2.Call(); // Outputs: 'FooCall' In this case foo->Call() would end up calling MyCall(Foo * object) whilst foo2.Call() call the original function (i.e Foo::Call(void) method). This is because the compiler will try to decide any virtual calls during compile time if possible (correct me if I'm wrong). Does that mean it does not matter if you patch the virtual table or not, as long as you use objects on the stack (not heap allocated)?

    Read the article

  • Java Concurrency in practice sample question

    - by andy boot
    I am reading "Java Concurrency in practice" and looking at the example code on page 51. This states that if a thread has references to a shared object then other threads may be able to access that object before the constructor has finished executing. I have tried to put this into practice and so I wrote this code thinking that if I ran it enough times a RuntimeException("World is f*cked") would occur. But it isn't doing. Is this a case of the Java spec not guaranting something but my particular implementation of java guaranteeing it for me? (java version: 1.5.0 on Ubuntu) Or have I misread something in the book? Code: (I expect an exception but it is never thrown) public class Threads { private Widgit w; public static void main(String[] s) throws Exception { while(true){ Threads t = new Threads(); t.runThreads(); } } private void runThreads() throws Exception{ new Checker().start(); w = new Widgit((int)(Math.random() * 100) + 1); } private class Checker extends Thread{ private static final int LOOP_TIMES = 1000; public void run() { int count = 0; for(int i = 0; i < LOOP_TIMES; i++){ try { w.checkMe(); count++; } catch(NullPointerException npe){ //ignore } } System.out.println("checked: "+count+" times out of "+LOOP_TIMES); } } private static class Widgit{ private int n; private int n2; Widgit(int n) throws InterruptedException{ this.n = n; Thread.sleep(2); this.n2 = n; } void checkMe(){ if (n != n2) { throw new RuntimeException("World is f*cked"); } } } }

    Read the article

  • HTML Helper/Text Box validation

    - by slandau
    I have this input on the view: <%= Html.TextBoxCurrentDateWithoutPermission("EffectiveDate", Model.EffectiveDate.HasValue ? Model.EffectiveDate.Value.ToString("dd-MMM-yyyy") : "", new string[] { PERMISSIONS.hasICAdvanced }, new { @class = "economicTextBox", propertyName = "EffectiveDate", onchange = "parseAndSetDt(this); ", dataType = "Date" })%> Here is the custom HTML Helper: public static MvcHtmlString TextBoxCurrentDateWithoutPermission( this HtmlHelper htmlHelper, string name, object value, string[] permissions, object htmlAttributes ) { foreach (string permission in permissions) { if (Chatham.Web.UI.Extranet.SessionManager.DisplayUser.IsInRole(permission)) { // the user has the permission => render the textbox return htmlHelper.TextBox(name, value, htmlAttributes); } } // the user has no permission => render a readonly checkbox var mergedHtmlAttributes = new RouteValueDictionary(htmlAttributes); mergedHtmlAttributes["disabled"] = "disabled"; return htmlHelper.TextBox(name, value == "" ? DateTime.Now : value, mergedHtmlAttributes); } The way this works now is, when a user does NOT have the permission passed in, the box is disabled. The way it needs to be -- if the user does NOT have the permission passed in, it needs to be enabled, however the only dates it can accept are todays date AND dates in the future. So I need JQuery validation (or just plain JS), for this textbox on the page for the following case: If the textbox is enabled AND the user does not have the permission, allow the user to input the current date or future dates ONLY.

    Read the article

  • Attaching methods to prototype from within constructor function

    - by Matthew Taylor
    Here is the textbook standard way of describing a 'class' or constructor function in JavaScript, straight from the Definitive Guide to JavaScript: function Rectangle(w,h) { this.width = w; this.height = h; } Rectangle.prototype.area = function() { return this.width * this.height; }; I don't like the dangling prototype manipulation here, so I was trying to think of a way to encapsulate the function definition for area inside the constructor. I came up with this, which I did not expect to work: function Rectangle(w,h) { this.width = w; this.height = h; this.constructor.prototype.area = function() { return this.width * this.height; }; } I didn't expect this to work because the this reference inside the area function should be pointing to the area function itself, so I wouldn't have access to width and height from this. But it turns out I do! var rect = new Rectangle(2,3); var area = rect.area(); // great scott! it is 6 Some further testing confirmed that the this reference inside the area function actually was a reference to the object under construction, not the area function itself. function Rectangle(w,h) { this.width = w; this.height = h; var me = this; this.constructor.prototype.whatever = function() { if (this === me) { alert ('this is not what you think');} }; } Turns out the alert pops up, and this is exactly the object under construction. So what is going on here? Why is this not the this I expect it to be?

    Read the article

  • How to add Flex 4 spark List Item custom properties

    - by maik3l
    I'm trying to make a simple flash application providing interface for taking tests as a high school assignment. One of the requirements is to use an XML file as data source.Now, having a List component bound to the XML file with questions consisting of data such as question body, question type (ie. single choice, multiple choice, open, image etc.) and possible answers (where applicable), I was wondering if I could add some additional data (and what is the best possible way to do so) to each question upon its transfer to the List component. I am trying to achieve two main goals with this: firstly, to mark the questions to which an answer has already been given, like with such code in ItemRenderer class: <s:Label color="{data.color}" text="{data.label}"/> where data.color would be set whenever the user gives an answer to a question. Secondly, while at it, I thought of such possibility as a great way to store answers given to particular questions. In this case, the Class of the answer object would have been Object, since there has to be many type of questions (where the answer could also be a Bitmap for example). This is a question of both how to do it and if it seems a good idea at all (and if no, if there is a better way?), because I am quite new to the whole Flash Builder and Flex thing and I am not really accustomed to all the possibilities and best practices. Thanks!

    Read the article

  • 2-Way databinding with Entity Framework and WPF DataGrid , is Possible ?

    - by Panindra
    i am working on POS application using SQL CE , WPF , Entity framework 3.5sp2 and iam trying to use data grid as my Order Entry Control for User to enter Products Order . Iam plannning to bind this to enitiy frmae work model , abd looking for 2 way updating ? private void button1_Click(object sender, RoutedEventArgs e) { using (MasterEntities nwEntities = new MasterEntities()) { var users = from d in nwEntities.Companies select new { d.CompanyId, d.CompanyName, d.Place }; listBox1.DataContext = users; dataGrid1.DataContext = users; // foreach (String c in customers) // { // MessageBox.Show(c.ToString()); // } } } When try to double clikc on the datagrid it through s a error with Caption " Invalid Operation Execption was unhandled " and Message " A TwoWay or OneWayToSource binding cannot work on the read-only property 'CompanyId' of type '<f__AnonymousType0`3[System.Int32,System.String,System.String]'. whats wrong here and my xaml coding goes like this <Grid> <ListBox Name="listBox1" ItemsSource="{Binding}" /> <Button Content="Show " Name="button1" Click="button1_Click" /> <DataGrid AutoGenerateColumns="False" Name="dataGrid1" ItemsSource="{Binding}" > <DataGrid.Columns> <DataGridTextColumn Header=" ID" Binding="{Binding CompanyId}"/> <DataGridTextColumn Header="Company Name" Binding="{Binding CompanyName}"/> <DataGridTextColumn Header="Place" Binding="{Binding Place}" /> </DataGrid.Columns> </DataGrid> </Grid> EDITED : i made the changes shown by @vorrtex, But, then i added another button to save the chages and in button click event i added follwing code , butit showing Updating error private void button2_Click(object sender, RoutedEventArgs e) { nwEntities.SaveChanges(); }

    Read the article

  • Event consumption in WPF

    - by webaloman
    I have a very simple app written in Silverlight for Windows Phone, where I try to use events. In my App.xaml.cs code behind I have implemented a GeoCoordinateWatcher which registers a gCWatche_PositionChanged method. This works ok, method is called after the position has been changed. What I want to do is fire an other event lets say DBUpdatedEvent after DB has been updated in the gCWatche_PositionChanged method. For this i delclared in the App.xaml.cs public delegate void DBUpdateEventHandler(object sender, EventArgs e); and I have in my App class: public event DBUpdateEventHandler DBUpdated; the event is fired like this in the end of gCWatche_PositionChanged method like this: OnDBUpdateEvent(new EventArgs()); and also I have declared : protected virtual void OnDBUpdateEvent(EventArgs e) { if (DBUpdated != null) { DBUpdated(this, e); } } Now I need to consume this event in my other Windows Phone app page which is a separate class PhoneApplicationPage. So I declared this method in this other Phone Page: public void DBHasBeenUpdated(object sender, EventArgs e) { Debug.WriteLine("DB UPDATE EVENT CATCHED"); } And in the constructor of this page I declared: DBUpdateEventHandler dbEH = new DBUpdateEventHandler(DBHasBeenUpdated); But when I test the application event is fired (OnDBUpdateEvent is called, but DBUpdated is null, therefore DBUpdated is not called - strange) and I have a problem that the other Phone Page is not catching the event at all... Any suggestions? How to catch that event. Thanks.

    Read the article

< Previous Page | 564 565 566 567 568 569 570 571 572 573 574 575  | Next Page >