multithreading

问题 I'm creating a 20-minute countdown timer application. I'm using JavaFX SceneBuilder to do this. The timer is composed of two labels (one for minutes, one for seconds--each composed of a CountdownTimer class object), and a progress bar (the timer looks like this). Each of these components are separate and running on separate threads concurrently to prevent the UI from freezing up. And it works. The problem: The three threads ( minutesThread , secondsThread , progressBarUpdaterThread ) I need

问题 I'm creating a 20-minute countdown timer application. I'm using JavaFX SceneBuilder to do this. The timer is composed of two labels (one for minutes, one for seconds--each composed of a CountdownTimer class object), and a progress bar (the timer looks like this). Each of these components are separate and running on separate threads concurrently to prevent the UI from freezing up. And it works. The problem: The three threads ( minutesThread , secondsThread , progressBarUpdaterThread ) I need

问题 If I understand correctly then when I create GUI swing components, for example I have this: public class frameExample extends JFrame{ public frameExample(){ //Here adding bunch if components setVisible(true); } } So as long as I don't call the setVisible method the components are being made from the thread the instance was created. So if in a class where i have my main method write: JFrame test=new frameExample(); and I sysout Thread.currentThread.getName(); in the constructor in frameExample

问题 Following up with Serial Port Communication solution I implemented the below design. My code uses com8 to communicate with a Serial Port Utility Application that is listening on com9 within the same machine, then sending back (manually I type a message and press a button) In my main I do this: MyClass MyObj = new MyClass(); var message = MyObj.SendThenRecieveDataViaSerialPort("Test"); And then in my class I have this: private static SerialPort MainSerialPort { get; set; } = new SerialPort();

问题 I am using concurrent.futures module to do multiprocessing and multithreading. I am running it on a 8 core machine with 16GB RAM, intel i7 8th Gen processor. I tried this on Python 3.7.2 and even on Python 3.8.2 import concurrent.futures import time takes list and multiply each elem by 2 def double_value(x): y = [] for elem in x: y.append(2 *elem) return y multiply an elem by 2 def double_single_value(x): return 2* x define a import numpy as np a = np.arange(100000000).reshape(100, 1000000)

问题 This is SAP PI requirement, Source System: XY_Client Middleware: PI System Target system : SAP The XML files are received to the PI system, for each XML file an internal file is generated to keep track of store_number, and count of xml files. How it works: suppose if XML_FILE_1 reaches PI, internal file called sequence_gen is created. the file contains the store number present in XML file and count will be initialized to 1. so first time, sequence_gen file contains Store: 1001 Count:1 (after

问题 public class Cls { public object Obj { get; set; } public async void Func() { Task.Run(() => { Thread.Sleep(999999999); this.Obj = new { }; }); } } public class Program { public static void Main(string[] args) { new Cls().Func(); } } Please consider the above codes and neglect if it makes sense first. In the above case, I did not store instance of Cls into any variable, seems that nothing is referencing that instance and it would be GC. However, there is a Task.Run() in side Func . The

问题 Is Thread.join() a full synchronization with flushing of caches etc. when performed of the thread beeing joined? 回答1: I think you're asking whether from thread T1 that calls join on T2, code in T1 reading data after the join() will definitely see changes written by T2. If that's the case, then the answer is yes, due to JLS 17.4.4: The final action in a thread T1 synchronizes-with any action in another thread T2 that detects that T1 has terminated. T2 may accomplish this by calling T1.isAlive(

问题 Is Thread.join() a full synchronization with flushing of caches etc. when performed of the thread beeing joined? 回答1: I think you're asking whether from thread T1 that calls join on T2, code in T1 reading data after the join() will definitely see changes written by T2. If that's the case, then the answer is yes, due to JLS 17.4.4: The final action in a thread T1 synchronizes-with any action in another thread T2 that detects that T1 has terminated. T2 may accomplish this by calling T1.isAlive(

问题 I'm trying to generate shared memory in a distributed manner; I also need the solution to be cross-platform. In order to do so, I need to synchronise the initialisation of this shared memory - using a mutex. This mutex, thus, needs to be shared. I've taken a look at this question: Interprocess reader/writer lock with Boost However, it suggests placing the mutex in shared memory, generated by a central process. This is the exact opposite of what I'm wanting to do. If I had this central process