multithreading

问题 I have a multithreaded application where I one producer thread(main) and multiple consumers. Now from main I want to have some sort of percentage of how far into the work the consumers are. Implementing a counter is easy as the work that is done a loop. However since this loop repeats a couple of thousands of times, maybe even more than a million times. I don`t want to mutex this part. So I went looking into some atomic options of writing to an int. As far as I understand I can use the

问题 I have a multithreaded application where I one producer thread(main) and multiple consumers. Now from main I want to have some sort of percentage of how far into the work the consumers are. Implementing a counter is easy as the work that is done a loop. However since this loop repeats a couple of thousands of times, maybe even more than a million times. I don`t want to mutex this part. So I went looking into some atomic options of writing to an int. As far as I understand I can use the

问题 I am calling a webservice in multi threaded environment. Lot of my calls fail due to operation time out or bad request but none of the calls fail if I do it in linear fashion which means there is problem with invoking webservice with multiple threads. After lot of analysis, I found out that there is limit of concurrent connection which is causing these exception so I fixed it by adding below code. ServicePointManager.DefaultConnectionLimit = 2 * _ThreadCount; What I dont know is the possible

问题 I am developing Rest APIs with Spring Boot which is deployed on AWS Beanstalk. Potentially, the service will be getting hits from thousands of clients every day. Therefore I would like to understand capability of Spring Boot of handling multiple requests. From what I read in Spring-Boot: Handle multiple requests concurrently and How to have thread safe controller in spring boot, it seems Spring Boot can handle requests concurrently while controller being thread safe. If two requests are made

问题 I have programmed an application using PySide2 with some 800 lines of code and now when I want to show a variable in the progress bar it crashes after a short while without any warning. Silently. Just now it dawned on me that my whole approach to this GUI building is probably incorrect. Can this code be saved somehow so that it can via signals set this progress bar from inside the thread without the application crashing? EDIT: this minimal code works and crashes but needs a small ui file.

问题 Im getting that famous "Can't create handler inside thread that has not called Looper.prepare()" error in my below code. based on most of my Google search result, this happens when i try to update UI from my none-ui-thread, but im not updating the UI at this point when i call the method from my other helper class (only after address has been returned); so please consult on why this is happening would be appreciated. package com.parspake.kookojapost; import android.app.ActionBar; import

问题 I'm working on a program using a large number of threads, each thread allocating in heap a few megabytes of memory. When these threads end, a large part of the RAM is kept by the program. Here is an example of code, allocating and freeing 1 MB in 500 threads, which shows this problem: #include <future> #include <iostream> #include <vector> // filling a 1 MB array with 0 void task() { const size_t S = 1000000; int * tab = new int[S]; std::fill(tab, tab + S, 0); delete[] tab; } int main() { std

问题 I need to create a GUI to show real-time data coming from the Serial port. I'm reading serial port data from a separate thread and I need to update GUI from there. My current implementation is like this. class Gui extends JFrame { private JLabel lbl = new JLabel(); .... void updateLabel(String text) { lbl.setText(text); } } class CommPortReceiver extends Thread { private Gui gui = new Gui(); void run() { gui.setVisible(true); .... while (true) { if (dataAvailable) { .... gui.updateLabel(data)

问题 This question already has answers here : How to remove elements from a generic list while iterating over it? (26 answers) Closed 6 years ago . I need help. I am working with an arraylist, and suddenly I get this error. An unhandled exception of type 'System.InvalidOperationException' occurred in mscorlib.dll Additional information: Collection was modified; enumeration operation may not execute. This is the code where it shows the exception... foreach (PC_list x in onlinelist) { if ((nowtime

问题 This question already has answers here : How to remove elements from a generic list while iterating over it? (26 answers) Closed 6 years ago . I need help. I am working with an arraylist, and suddenly I get this error. An unhandled exception of type 'System.InvalidOperationException' occurred in mscorlib.dll Additional information: Collection was modified; enumeration operation may not execute. This is the code where it shows the exception... foreach (PC_list x in onlinelist) { if ((nowtime