multithreading

问题 In this code snippet, the application sleeps for the interval, but instead of appending TEXT to textStatus(TextView variable), it displays an error that Something went wrong and application is closing. Thread time_manager = new Thread(){ public void run(){ int interval = 2000; try{ sleep(interval); textStatus.append("\nTEXT\n"); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally{ } } }; What part am I doing wrongly? 回答1: To update the UI you

问题 In this code snippet, the application sleeps for the interval, but instead of appending TEXT to textStatus(TextView variable), it displays an error that Something went wrong and application is closing. Thread time_manager = new Thread(){ public void run(){ int interval = 2000; try{ sleep(interval); textStatus.append("\nTEXT\n"); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally{ } } }; What part am I doing wrongly? 回答1: To update the UI you

问题 I'm working on a program involving a multithreaded server, in which I want messages sent by clients to be echoed back to every client currently connected to the server. It doesn't exactly do this. I will send a message from a client to the server, and it will echo back to that same client. Not to the other client. Let's say, with one client I sequentially type "One" then "Two" then "Three". The exchange will be something like this: Client 1: "One" Echo from Server ON Client 1's console: "One"

问题 I'm trying to create a producer-consumer program, where the consumers must keep running until all the producers are finished, then consume what's left in the queue (if there's anything left) and then end. You can check my code bellow, I think I know where the problem (probably deadlock) is, but I don't know how to make it work properly. #include<iostream> #include<cstdlib> #include <queue> #include <thread> #include <mutex> #include <condition_variable> using namespace std; class Company{

问题 I'm getting InvalidOperationException . This code is running in a thread. I've delegate it to the UI thread to handle the UI. Is the problem occuring because of my resources? BitmapImage logo = new BitmapImage(); logo.BeginInit(); logo.UriSource = new Uri("pack://application:,,,/LiarDice;component/" + imagePath); logo.EndInit(); currentGuessDice.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, new Action(delegate() { currentGuessDice.Source = logo; })); I changed my code

问题 I am new to java, and I am trying to write a program that takes two parameters: the number until which we have to sum prime numbers the number of threads in which we have to do this So I use a method named Eratosthene that stores an array of boolean and if a number is prime, we mark it true and after that we mark all the multiples of this number false. I try to devide my array into sub arrays for each thread and do the operation in each sub arrays, and at the end sum all the results of sub

问题 Environment: Apache-tomcat-7.0.53, CentOS release 6.6 (Final), Java 1.8, Mongo 2.6 Design of our App We have most of the calls handled with normal servlets(traditional synchronous ones). We do have a 2 asynchronous servlets(servlet 3.0) which delegate their work to ThreadPoolExecutors(threads named http-async-workers). Problem: We have a database heavy application, but it was performing quite well until 3500ccu. But when we ramped up the CCU to 7000CCU, to measure the scalability factor, we

问题 I have a server accepting clients that has a stop() method that closes the server down, which is causing a java.nio.AsynchronousCloseException that I'd like to resolve. The stop() method is called on a different thread, which is what is causing the race condition I believe. Here is my code: public void run() { InetSocketAddress addr = new InetSocketAddress(provider.getConnection(), 12354); try { server = ServerSocketChannel.open(); server.configureBlocking(true); server.socket().bind(addr);

问题 Quote from java concurrency in practice: Using timed lock acquisition to acquire multiple locks can be effective against deadlock even when timed locking is not used consistently throughout the program. If a lock acquisition times out, you can release the locks, back off and wait for a while, and try again, possibly clearing the deadlock condition and allowing the program to recover. ( This technique works only when the two locks are acquired together; if multiple locks are acquired due to

问题 I need to sync web database in my coredata, for which I perform service api calls. I am using Alamofire with Swift 3 . There are 23 api calls, giving nearly 24k rows in different coredata entities. My problem: These api calls blocks UI for a minute, which is a long time for a user to wait. I tried using DispatchQueue and performing the task in background thread, though nothing worked. This is how I tried : let dataQueue = DispatchQueue.init(label: "com.app.dataSyncQueue") dataQueue.async {