notify

How to use wait and notify protocol with multiple threads

由 吃可爱长大的小学妹 提交于 2019-12-09 18:15:07
问题 Specifically, can somebody tell me what is wrong with this piece of code. It should start the threads, so should print "Entering thread.." 5 times and then wait until notifyAll() is called. But, it randomly prints "Entering.." and "Done.." and still keeps waiting on others. public class ThreadTest implements Runnable { private int num; private static Object obj = new Object(); ThreadTest(int n) { num=n; } @Override public void run() { synchronized (obj) { try { System.out.println("Entering

WPF custom DependencyProperty notify changes

由 蓝咒 提交于 2019-12-09 16:13:43
问题 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 DependencyProperty BackgroundProperty = DependencyProperty.Register("Background", typeof(MyBackground), typeof(MyComponent), new FrameworkPropertyMetadata(default(MyBackground), new PropertyChangedCallback

Java waiting Thread doesn't resume after notify

由 ∥☆過路亽．° 提交于 2019-12-08 11:50:26
问题 I have below program having 2 threads T1 and T2. T1 is running first and goes into waiting state. T2 is calling notify. Why T1 thread doesn't resumes and prints "Thread-0 is waken up" public class WaitNotifyTest{ public static void main(String[] args) { Thread t1 = new Thread(new Runnable() { @Override public void run() { synchronized (this) { System.out.println(Thread.currentThread().getName() + " is running"); try { wait(); } catch (InterruptedException e) { e.printStackTrace(); } System

Producer consumer code with wait/notify doesn't work on second produce

由 戏子无情 提交于 2019-12-08 08:17:38
问题 This is a follow-up question from my previous question asked here. I am using a PriorityBlockingQueue now. I changed my producer to the following: synchronized(Manager.queue) { Manager.queue.add(new Job()); Manager.queue.notify(); } And changed Consumer to the following. Full code skeleton is here: //my consumer thread run() public void run() { synchronized(Manager.queue) { while (Manager.queue.peek() == null) { System.out.println("111111111111111"); try { Manager.queue.wait(); } catch

Is wait(1) in a non-blocking while(true)-loop more efficient than using wait() and notify()?

由 穿精又带淫゛_ 提交于 2019-12-08 08:17:04
问题 Does a while(true) Java loop together with wait(1) use more or less resources than a blocking loop with wait() and notify() ? And do the CPU cores have some special (hardware) implementations to allow wait(1) ? If yes, are there any limitations while working with such non-blocking loops? An example: while(true){ wait(1); //do the job here... } (Just a note: Without the wait(1) a core would go radical 100% in a while(true) loop...) 回答1: As to the original question of why while (true); takes up

Program gets halted: wait() and notify()

由 ぃ、小莉子 提交于 2019-12-08 03:31:07
问题 I am trying to achieve this: Created two different threads, one prints odd numbers, one prints even numbers. Once one thread prints a number, it has to wait for the other thread and so on, that is one-after-other. To achieve this, i am using synchronized block along with wait() and notify(). I am creating a class whose's object will be used to pass to synchronized block in both the threads. Here is the code: --> This is used object which will be passed to synchronized block. package com.vipin

Is wait(1) in a non-blocking while(true)-loop more efficient than using wait() and notify()?

由 跟風遠走 提交于 2019-12-08 03:16:24
Does a while(true) Java loop together with wait(1) use more or less resources than a blocking loop with wait() and notify() ? And do the CPU cores have some special (hardware) implementations to allow wait(1) ? If yes, are there any limitations while working with such non-blocking loops? An example: while(true){ wait(1); //do the job here... } (Just a note: Without the wait(1) a core would go radical 100% in a while(true) loop...) As to the original question of why while (true); takes up more CPU than while (true) { wait(1); } , consider: a modern CPU can perform billions of instructions per

Issue with Notification Manager on android

由 拈花ヽ惹草 提交于 2019-12-08 02:06:37
问题 I'm trying to notify using a button, but both Notification and setLatestEventInfo is deprecated. Two errors: 1.The constructor Notification(int, CharSequence, long) is deprecated Notification notify = new Notification(android.R.drawable.stat_notify_more, "Hello all", System.currentTimeMillis()); 2.The method setLatestEventInfo(Context, CharSequence, CharSequence, PendingIntent) in the type Notification is not applicable for the arguments (Context, CharSequence, CharSequence, Intent) notify

How to solve starvation with notify and notifyall?

由 回眸只為那壹抹淺笑 提交于 2019-12-08 02:02:41
问题 How to solve starvation with notify and notifyall ? If we have 4 threads, waiting to acquire a lock on same obj,and the current thread calls notify() The JVM will select any one thread. Is it possible that thread which called notify() , can again be picked by JVM, as after calling notify() , it would be also in waiting thread list. This might lead to starvation problem if one of the thread is invoked more number of times than others, unless there is some mechanism where longest waiting thread

how to notify java desktop clients about changes from server?

由 旧街凉风 提交于 2019-12-07 07:54:44
问题 I would like to develop a desktop application with Java (I've got very basic knowledge of Java). It'll run on the client's computer and will pull information from the server hosted in the internet. I can set a schedule task to connect to the server every 2minutes and check for any update/changes but I don't think it's a very good idea. Is there any way to let the clients know about the changes? For example, when every there would a change server will send a notification to the clients to
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