Why does this test program result in a java.lang.IllegalMonitorStateException? public class test { static Integer foo = new Integer(1); public static void main(String[] args) { synchronized(foo) { foo++; foo.notifyAll(); } System.err.println("Success"); } } Result: Exception...
Say I have a queue full of tasks which I need to submit to an executor service. I want them processed one at a time. The simplest way I can think of is to: Take a task from the queue Submit it to the executor Call .get on the returned Future and block until a result is available Take another task from the queue... However, I am try...
Hello, I have 2 matrices and I need to multiply them and then print the results of each cell. As soon as one cell is ready I need to print it, but for example I need to print the [0][0] cell before cell [2][0] even if the result of [2][0] is ready first. So I need to print it by order. So my idea is to make the printer thread wait until...
Hi All, I am working on the application (C# 2.0). I have implemented single instance in it. Everything is fine. If i run the application again, it shows messagebox saying "instance is already running". Actually i don't want to show the message through messagebox. I want to show this message using Balloon tip of already running instan...
Hi, I have a JApplet which is used for chat. I would like to make it possible that when the applet is minimised and a chat message is received by the user, the minimised window becomes orange (and thus shows the user that something has occurred). How is it possible to make the applet do this? Thanks, Tim ...
Hi, I am running some time-consuming executables with different parameters assigned in a loop as background jobs in parallel. Here is a toy example and its output: bash-3.2$ set -o notify bash-3.2$ for (( i=0 ; i < 4 ; i+=2 )); do > sleep ${i} & > done [1] 32394 [2] 32395 bash-3.2$ [1]- Done sleep ${i} [2]+ Done ...
Every Java Object has the methods wait() and notify() (and additional variants). I have never used these and I suspect many others haven't. Why are these so fundamental that every object has to have them and is there a performance hit in having them (presumably some state is stored in them)? EDIT to emphasize the question. If I have a ...
Hi Experts, Please define why the wait() and notify() methods are in Object class and not in Thread class? Thanx ...
Hi, I always struggle with sending messages between objects. Consider the hierarchy of objects of a quiz: Quiz QuestionList Question AnswerList Answer So: a Quiz has a QuestionList a QuestionList has multiple Questions a Question has an AnswerList a AnswerList has multiple Answers When an Answer gets clicked (we're talkin...
I'm writing a simulation of Bananagrams for fun. I want to use concurrency but I'm not entirely sure how. I have a main method in a Game class. Each of the player threads works towards a solution. At certain points, a player will "peel". During this operation, every player is dealt a new tile. One of the player threads must notify the G...
This link http://msdn.microsoft.com/en-us/library/aa772153(VS.85).aspx says: You can register up to five notification requests on a single LDAP connection. You must have a dedicated thread that waits for the notifications and processes them quickly. When you call the ldap_search_ext function to register a notification request, the funct...
What can cause that i get IllegalMonitorStateException in this code synchronized(syncCount){ syncCount--; syncCount.notify(); } I'm little confused, since, as far as I know running thread must have monitor on object who's notify is called. It looks to me that my code can not be wrong, but somehow it is. ...
Hi, Is it possible to make a service running in backgroud to be notified when an arbritary activity/application is started and ended by a user? I want to use it to log how often and for how long different applications are used in Android. ...
Can I get a complete simple scenario i.e. tutorial that suggest how this should be used, specifically with a Queue? ...
Hi, i'm a computer science student working on a Yahoo Messenger - like program implemented in Java. My problem is that whenever the JTextArea inside my frame contains new message updates, the user must be prompted even when his/her frame is minimized. Is there a workaround on how to make the JFrame on the taskbar blink when updates are ...
My question is very similar to this one except that my background process was started from a script. I could be doing something wrong but when I try this simple example: #!/bin/bash set -mb # enable job control and notification sleep 5 & I never receive notification when the sleep background command finishes. However, if I execute t...
I need to find out how to perform some action (flush cache) when an object of type X is updated. So when I save object of type Y, nothing is done, when I save unchanged object of type X nothing should happed, but when this object is changed and UPDATE is made, I want to know it. I tried various NHibernate events (IPostUpdateEventListe...
Hey guys I have a class called MyComponent and it has a DependencyProperty caled BackgroundProperty. public class MyComponent { public MyBackground Background { get { return (MyBackground)GetValue(BackgroundProperty); } set { SetValue(BackgroundProperty, value); } } public static readonly DependencyPrope...
I have a gridview were I define some columns, like this... <GridViewColumn.CellTemplate> <DataTemplate> <TextBlock Text="{Binding MyProp}" /> </DataTemplate> </GridViewColumn.CellTemplate> I bind my g...
I've been using an HTTP POST to a php file to change entries in a given MySQL database. Essentially, the second the value changes, I would like the user that is viewing the database table to be notified. For now my temporary solution is to auto refresh a page displaying the table to keep it updated but I feel like there has to be a more ...