Search Results

Search found 23474 results on 939 pages for 'event dispatch thread'.

Page 18/939 | < Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >

  • Is this (Lock-Free) Queue Implementation Thread-Safe?

    - by Hosam Aly
    I am trying to create a lock-free queue implementation in Java, mainly for personal learning. The queue should be a general one, allowing any number of readers and/or writers concurrently. Would you please review it, and suggest any improvements/issues you find? Thank you. import java.util.concurrent.atomic.AtomicReference; public class LockFreeQueue<T> { private static class Node<E> { E value; volatile Node<E> next; Node(E value) { this.value = value; } } private AtomicReference<Node<T>> head, tail; public LockFreeQueue() { // have both head and tail point to a dummy node Node<T> dummyNode = new Node<T>(null); head = new AtomicReference<Node<T>>(dummyNode); tail = new AtomicReference<Node<T>>(dummyNode); } /** * Puts an object at the end of the queue. */ public void putObject(T value) { Node<T> newNode = new Node<T>(value); Node<T> prevTailNode = tail.getAndSet(newNode); prevTailNode.next = newNode; } /** * Gets an object from the beginning of the queue. The object is removed * from the queue. If there are no objects in the queue, returns null. */ public T getObject() { Node<T> headNode, valueNode; // move head node to the next node using atomic semantics // as long as next node is not null do { headNode = head.get(); valueNode = headNode.next; // try until the whole loop executes pseudo-atomically // (i.e. unaffected by modifications done by other threads) } while (valueNode != null && !head.compareAndSet(headNode, valueNode)); T value = (valueNode != null ? valueNode.value : null); // release the value pointed to by head, keeping the head node dummy if (valueNode != null) valueNode.value = null; return value; }

    Read the article

  • java share data between thread

    - by ayush
    i have a java process that reads data from a socket server. Thus i have a BufferedReader and a PrintWriter object corresponding to that socket. Now in the same java process i have a multithreaded java server that accepts client connections. I want to achieve a functionality where all these clients that i accept can read data from the BufferedReader object that i mentioned above.(so that they can multiplex the data) How do i make these individual client threads read the data from BuffereReader single object? Sorry for the confusion.

    Read the article

  • thread local stroage macosx

    - by anon
    http://developer.apple.com/mac/library/documentation/DeveloperTools/gcc-4.0.1/gcc/Thread_002dLocal.html Documents __thread yet my g++ compalins that __thread is not suppoted on my arch (Leopard on Macbookpro). Why is this? And how do I get around it?

    Read the article

  • Cache consistency & spawning a thread

    - by Dave Keck
    Background I've been reading through various books and articles to learn about processor caches, cache consistency, and memory barriers in the context of concurrent execution. So far though, I have been unable to determine whether a common coding practice of mine is safe in the strictest sense. Assumptions The following pseudo-code is executed on a two-processor machine: int sharedVar = 0; myThread() { print(sharedVar); } main() { sharedVar = 1; spawnThread(myThread); sleep(-1); } main() executes on processor 1 (P1), while myThread() executes on P2. Initially, sharedVar exists in the caches of both P1 and P2 with the initial value of 0 (due to some "warm-up code" that isn't shown above.) Question Strictly speaking – preferably without assuming any particular CPU – is myThread() guaranteed to print 1? With my newfound knowledge of processor caches, it seems entirely possible that at the time of the print() statement, P2 may not have received the invalidation request for sharedVar caused by P1's assignment in main(). Therefore, it seems possible that myThread() could print 0. References These are the related articles and books I've been reading. (It wouldn't allow me to format these as links because I'm a new user - sorry.) Shared Memory Consistency Models: A Tutorial hpl.hp.com/techreports/Compaq-DEC/WRL-95-7.pdf Memory Barriers: a Hardware View for Software Hackers rdrop.com/users/paulmck/scalability/paper/whymb.2009.04.05a.pdf Linux Kernel Memory Barriers kernel.org/doc/Documentation/memory-barriers.txt Computer Architecture: A Quantitative Approach amazon.com/Computer-Architecture-Quantitative-Approach-4th/dp/0123704901/ref=dp_ob_title_bk

    Read the article

  • Is this ruby code thread safe?

    - by Ben K.
    Is this code threadsafe? It seems like it should be, because @myvar will never be assigned from multiple threads (assuming block completes in < 1s). But do I need to be worried about a situation where the second block is trying to read @myvar as it's being written? require 'rubygems' require 'eventmachine' @myvar = Time.now.to_i EventMachine.run do EventMachine.add_periodic_timer(1) do EventMachine.defer do @myvar = Time.now.to_i # some calculation and reassign end end EventMachine.add_periodic_timer(0.5) do puts @myvar end end

    Read the article

  • Assign an existing click event function to another click event using jquery

    - by Peter Delahunty
    Ok so i have some html like this: <div id="navigation"> <ul> <li> <a>tab name</a> <span class="delete-tab">X</span> </li> <li> <a>tab name</a> <span class="delete-tab">X</span> </li> <li> <a>tab name</a> <span class="delete-tab">X</span> </li> <li class="selected"> <a>tab name</a> <span class="tab-del-btn">X</span> </li> </ul> </div> I then have javascript that is excuted on the page that i do not control (this is in liferay portal). I want to then manipulate things afterwards with my own custom javascript. SO... For each of the span.delete-tab elements an on-click event function has been assign earlier. It is the same function call for each span. I want to take that function (any) and call it from the click event of the span.tab-del-btn ? This is what i tried to do: var navigation = jQuery('#navigation'); var navTabs = navigation.find('.delete-tab'); var existingDeleteFunction = null; navTabs.each(function (i){ var tab = jQuery(this); existingDeleteFunction = tab.click; }); var selectedTab = jQuery('#navigation li.selected'); var deleteBtn = selectedTab.find('.tab-del-btn'); deleteBtn.click(function(event){ existingDeleteFunction.call(this); }); It does not work though. existingDeleteFunction is not the original function it is some jquery default function. Any ideas?

    Read the article

  • How do I dispatch to a method based on a parameter's runtime type in C# < 4?

    - by Evan Barkley
    I have an object o which guaranteed at runtime to be one of three types A, B, or C, all of which implement a common interface I. I can control I, but not A, B, or C. (Thus I could use an empty marker interface, or somehow take advantage of the similarities in the types by using the interface, but I can't add new methods or change existing ones in the types.) I also have a series of methods MethodA, MethodB, and MethodC. The runtime type of o is looked up and is then used as a parameter to these methods. public void MethodA(A a) { ... } public void MethodB(B b) { ... } public void MethodC(C c) { ... } Using this strategy, right now a check has to be performed on the type of o to determine which method should be invoked. Instead, I would like to simply have three overloaded methods: public void Method(A a) { ... } // these are all overloads of each other public void Method(B b) { ... } public void Method(C c) { ... } Now I'm letting C# do the dispatch instead of doing it manually myself. Can this be done? The naive straightforward approach doesn't work, of course: Cannot resolve method 'Method(object)'. Candidates are: void Method(A) void Method(B) void Method(C)

    Read the article

  • jQuery event trigger - cancelable event

    - by Dismissile
    I have created a jquery plugin which is triggering an event: $.fn.myplugin = function(options) { this.on("foo.myplugin", options.foo); this.on("bar.myplugin", options.bar); }; I want to check if foo has been canceled by a user and prevent bar from being triggered: // trigger foo this.trigger("foo.myplugin"); // how do I check if foo was canceled if( !fooCanceled ) { this.trigger("bar.myplugin"); } How can I check if foo was canceled to prevent bar from being triggered? jQuery UI does something similar to this, but it did not work when I tried: if (this._trigger("search", event) === false) { return; } I tried something similar to this: if( this.trigger("foo.myplugin") === false ) { return; } this.trigger("bar.myplugin"); But bar was still being triggered.

    Read the article

  • How do I make a background thread in Java that allows the main application to exit completely? This

    - by Bob
    I have a Java application that creates a new thread to do some work. I can launch the new thread with no problems. When the "main" program terminates, I want the thread I created to keep running - which it does... But the problem is, when I run the main application from Eclipse or from Ant under Windows, control doesn't return unless the background process is killed. If I fork the main java process in ant, I want control to return to ant once the main thread is done with its work... But as it is, ant continues to wait until both the main process and the created thread are both terminated. How do I launch the thread in the background such that control will return to ant when the "main" application is finished? (By the way, when I run the same application under Linux, I am able to do this with no problems).

    Read the article

  • Java Thread - Memory consistency errors

    - by Yatendra Goel
    I was reading a Sun's tutorial on Concurrency. But I couldn't understand exactly what memory consistency errors are? I googled about that but didn't find any helpful tutorial or article about that. I know that this question is a subjective one, so you can provide me links to articles on the above topic. It would be great if you explain it with a simple example.

    Read the article

  • Drupal Event/Calendar Module not storing event time

    - by Selino
    Hello, all. I have installed a fresh copy of Drupal on an Xampp server. Within that install is a collection of modules for creating an event calendar. There's actually a great instructional video at http://www.youtube.com/watch?v=qO4TeEydtMs for getting all the necessary fields up. So far everything is working except... the events won't store the time as stated in the edit field. No matter what I do in the edit mode as admin or otherwise the time always says 12pm and the event on the calendar says "All Day". I know this is pretty obscure but I figured why not try and ask. Thanks.

    Read the article

  • ID generator with local static variable - thread-safe?

    - by Poseidon
    Will the following piece of code work as expected in a multi-threaded scenario? int getUniqueID() { static int ID=0; return ++ID; } It's not necessary that the IDs to be contiguous - even if it skips a value, it's fine. Can it be said that when this function returns, the value returned will be unique across all threads?

    Read the article

  • Forward event from custom UIControl subclass

    - by ggould75
    My custom subclass extend UIControl (MyCustomUIControl) Basically it contains 3 subviews: UIButton (UIButtonTypeCustom) UIImageView UILabel All the class works great but now I want to connect some events generated from this class to another. In particular when the button is pressed I want to forward the event to the owner viewcontroller so that I can handle the event. The problem is that I can't figure out how to implement this behaviour. Within EditableImageView I can catch the touch event using [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside] but I don't know how to forward it inside of the buttonPressed selector. I also tried to implement touchesBegan but it seems never called... I'd like to capture the button press event from the viewcontroller in this way: - (void)viewDidLoad { [super viewDidLoad]; self.imageButton = [[EditableImageView alloc] initWithFrame:CGRectMake(50.0f, 50.0f, 80.0f, 80.0f)]; [imageButton addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:imageButton]; [imageButton setEditing:NO]; } This is my UIControl subclass initialization method: - (id)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) { [self setBackgroundColor:[UIColor clearColor]]; button = [UIButton buttonWithType:UIButtonTypeCustom]; button.frame = CGRectMake(0.0f, 0.0f, frame.size.width, frame.size.height); [button setImage:[UIImage imageNamed:@"nene_70x70.png"] forState:UIControlStateNormal]; [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; [self addSubview:button]; transparentLabelBackground = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"editLabelBackground.png"]]; transparentLabelBackground.hidden = YES; [self addSubview:transparentLabelBackground]; // create edit status label editLabel = [[UILabel alloc] initWithFrame:CGRectZero]; editLabel.hidden = YES; editLabel.userInteractionEnabled = NO; // without this assignment the button will not be clickable editLabel.textColor = [UIColor whiteColor]; editLabel.backgroundColor = [UIColor clearColor]; editLabel.textAlignment = UITextAlignmentLeft; UIFont *labelFont = [UIFont systemFontOfSize:16.0]; editLabel.font = labelFont; editLabel.text = @"edit"; labelSize = [@"edit" sizeWithFont:labelFont]; [self addSubview:editLabel]; } return self; } Thanks.

    Read the article

  • ItemAdded Event for document library in sharepoint 2007

    - by Azra
    hi I am having a document library in share point 2007, I want to validate certain custom properties before a document is uploaded Or Properties are entered when Edit properties event is cliked. I am trying to validate the fields at ItemAdding event whne a documetn is uploaded , however when EditForm.aspx opens up for editing properties, no events firs. How can I troubleshoot the issue? thanks azra

    Read the article

  • event for textbox update

    - by Richard
    I have a textbox and want an event triggered whenever it is updated, whether through key presses, pasted from clipboard, or whatever else is possible. Is binding to the keyup event sufficient or is there a better way?

    Read the article

  • Customizing Mail Message in SSIS Event Handler

    - by Eric Ness
    I want to add an email notification to an SSIS 2005 package event handler. I've added a Send Mail task to the event handler. I'd like to customize the email body to include things like the error description. I've tried including @[System::ErrorDescription] in the MessageSource field, but the mail message doesn't include the value of ErrorDescription only the name of the variable.

    Read the article

  • How to add a SaveOrUpdateCopy event listener in NHibernate

    - by skrishna
    How can I add a event listener for SaveOrUpdateCopy in NHibernate ? I see that the ListenerType enumeration does not have a 'SaveOrUpdateCopy' type. I tried using the 'Merge' type, but that adds it to the MergeEventListeners collection. The SaveOrUpdateCopy invokes the events from the SaveOrUpdateCopyEventListeners collection. How can I add my event class to the SaveOrUpdateCopyEventListeners collection in NHibernate? Any help is appreciated.

    Read the article

< Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >