[multithreading] Forum Topics

Hi, i'm havnig problem with calling CreateThread. The problem is that it gives me a conversion error from const void* to void* [CODE=Ccplusplus]DWORD dwThreadId; HANDLE myThread; myThread = CreateThread( NULL, 0, MyThreadFunction, "HELLO", 0, &dwThreadId); [/CODE] dwThreadId id is the problem, the function is supose to take a pointer to …

Hello. I am trying to build a simple UDP multi-threaded echo server in `C` using `libhv` (library is using non-blocking events). Basically i am trying to combine https://github.com/ithewei/libhv/blob/master/examples/udp_echo_server.c with the threading of https://github.com/ithewei/libhv/blob/master/examples/multi-thread/one-acceptor-multi-workers.c I do this because i will have high amount of traffic and multiple threads will be needed …

Hello , I have a small question using Parrallism in c# , why did Microsoft came up with Task Parallel Library(TPL) .. why they did not use only threads in other words what did the TPL overcame in the threads problems?? Can some one help me to understand?

I am trying to make a simple HTTP/HTTPS service discovery in C. For this app i use `pthread` as there is no other better cross platform options for this, but i get some strange errors. **PROBLEM1 : thread_submit has do be dynamically modified at the run time. Right now it …

## Introduction ## When working with WorkManager, it is important to know how to provide input data to your Workers. In this tutorial, we will learn how to provide basic input data to a Worker as well as when Workers are chained together. ## Goals ## At the end of …

## Introduction ## Whenever we want to modify numbers from multiple threads running concurrently, such as modifying a counter, one of the best options is to use the AtomicX classes. The most basic numeric atomic classes are AtomicInteger and AtomicLong. In this tutorial, we will learn how to use the …

## Introduction ## With coroutines in Kotlin, we are able to execute suspending functions without blocking the current thread. By default, most coroutine builder functions use the `Dispatchers.Default` context, but it is also possible to use other implementations of `CoroutineContext`. In this tutorial, we will learn about the 2 `CoroutineDispatchers`: …

This code causes an exception: dim box as new mult() box.show <-------- cannot access a disposed object

## Introduction ## This tutorial introduces the `CyclicBarrier` class and teaches you how to use it. ## Goals ## At the end of this tutorial, you would have learned: 1. How to use `CyclicBarrier` to synchronize tasks across multiple threads. ## Prerequisite Knowledge ## 1. Intermediate Java. 2. Basic knowledge …

Write a C++ program to ask user to input last two day’s temperature for two different cities. Then your program must be capable of displaying user data. This program functionality can be performed in many different ways but you are directed to do it using multidimensional arrays.

Hi everyone, I am working on an app and trying to create a corrector and I am using keyboard module for the correction. I have created a class, which reads pressed events and displays them to screen, and its action are dependent to a variable passed to the constructor. If …

hi i want some change in this code. let one writer, one reader at the same time. Writer has preference. package test; import java.util.concurrent.Semaphore; class ReaderWritersProblem { static Semaphore readLock = new Semaphore(1); static Semaphore writeLock = new Semaphore(1); volatile static int readCount = 0; static class Read implements Runnable …

Hi, I have a problem, because I have a list, in which I'd like to be able to add and remove components, but in other thread I use components from this list. Is there a safe way to operate over this list? Would using synchronized functions (one for drawing, one …

I'm trying to create a multicolor table (composed by buttons) where every X seconds a thread change the color of its button. The first thing I did was manage the threads with a semaphore, but then I realized that maybe it wasn't necessary since I want that each button changes …

All, For the life of me I cannot get this program to compile. The error message "error: non-static variable this cannot be referenced from a static context" occurs on lines 23 and 24. Here is the entire program: [CODE]public class ThreadTest { public static int x = 0; public class …

I had a cool idea concerning threading in C#. I was reading a book called "CLR via C#" and it was discussing threading, and how people should seldom use actual thread objects, and instead should use the thread pooling services. The reason being they spool up worker threads for you …

Hi. im trying to append a text file that is created by another class via another class which are threads. for example, i have : class AClass(QThread): def run(self): with open("Log.txt", "w") as h: h.write("Blabla \n") class BClass(QThread): def run(self): with open("Log.txt", "a") as t: t.write("new line of txt \n") …

Hi all, So before I went and posted ~800 lines of code, I have 2 questions: 1: What is the preferred way for us to post "complex" C++ (of course, this is just a .h, .cpp, and main cpp but it's still a lot of lines) that wont just be …

Hello. As from the topic title, i am trying to work a multithread GUI where the progress bar indicates the running process completion (like we always see when we are installing/uninstalling/downloading). I've read a couple of written tutorials and some other forums discussions regarding the progress bar and multithreading. I've …

I am trying to learn Volatile keyword in Multi Threading and I came across this statement: *Volatile is preferred in cases when one thread reads and writes a shared variable and other threads just read the same. Whereas if there are more than 2 threads performing read and write both …

I am trying to understand the SynchronizedMap and I ran the below code. I get the below Output with an exception. According to my understanding the exception is caused when the get() methods are trying to access the syncmap when a thread is still executing a write on the map …

In the below code about the synchronisation between threads, according to the output generated why is the control being transferred to the execution of the new thread despite the lock being acquired for the same object "dt" in the main method ? public class DemoThread extends Thread { public DemoThread() …

I am trying to run the below concurrency code: import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; public class TestThread { public static void main(final String[] arguments) throws InterruptedException { ExecutorService executor = Executors.newSingleThreadExecutor(); try { executor.submit(new Task()); System.out.println("Shutdown executor"); executor.shutdown(); executor.awaitTermination(5, TimeUnit.SECONDS); } catch (InterruptedException e) { System.err.println("tasks interrupted"); } finally …

Hi, I'm developing a windows forms based software that process various '.log' files and provides the output to the user. I've implemented a stop button to stop the processing of the files and when the button is clicked, a message box would display with Yes/No options. The process thread keeps …

Hi guys; I'm new in python and thread ,i start learning by create a simple code but i find some defficult this code below have some function and thread also Queue function to share data between thread this is a part of my code: def PutChar(Ch): #ask user to put …

how to count repeated words from logfiles using java threads

Hi everyone, I am working on a coin collection app, and I have recently started integrating core data into my app. My app is of the following format: I have a core data database which stores custom CoinCategory objects and each CoinCategory object has an array of Coin objects. This …

0 down vote favorite I have created a network scanner, that looks for a specific port on a range of IP's. I would like to thread the application but I am getting and error message ERROR: for worker in range(network.hosts): TypeError: 'method' object cannot be interpreted as an integer Now …

I'm currently working on multithreading with PyAudio and Pygame, but when I try to run the audio, I get an error saying "OSError: [Errno -9996] Invalid output device (no default output device)." So far I've tried these on Terminal: >>> import pyaudio >>> pa = pyaudio.PyAudio() >>> pa.get_default_input_device_info() {'name': 'Built-in …

1. Measuring the effect of Parallelization Using one of the suggested methods in class ( p-threads, OpenMP, C-Sharp or Java Threads) implement an application that adds two integer vectors (A,B) and store the result on vector C. The size of these vectors is to be set at 67108864. Measure the …

I have two forms the first FrmRecipe.vb form has all my calulations and functions in it the second FrmReports has a crystal report viewer with loads of reports. I am trying to call the report as a thread so that the main from is still working however when the treads …

Hello Members, I want to write a C program which creates two threads and uses a semaphore (as a critical section) to sleep for 1 second and then terminate. I am having a hard time with some of the C Syntax for semaphores. Is it possible to post an example …

1) While working dates, when and why the local time and universal times are used? 2) Which multi-threaded program is recommended for reducing CPU usage? Why?

Computer programs are complex enough beasts when they are just doing one thing at a time When you start to explore the world of threads, you end up with programs that do more than one thing at once, and life can get very complicated. There are two specific conditions that …

Hi , Below code prints odd and even numbers using two threads.code works correctly . But i am unable to figure out whether it works in all scenarios. My doubtful scenario is: Lets say `evenfun` thread is invoked first when the value of `count` is 2 , so the thread …

Hello dear memebers, after searching for a multiple chat client i have come across a multithreading chat system which i have attached the code .I have taken the code of the server class and added it to my application form as well as the gui.My question is(well i know it …

Hi, I would linke to know what is the best way to synchronise the shared memory segment. is threads usage are also advisible whie synhcronising the shared memory segement. in what circumstances we should use threads or semaphore to synchronize the memory segment.

Hi Im trying to Populate my datagridview from data scraped off of webpage i Want to be able to report progress when datagrid finished updating.. with a progressbar.. Please Help!!!!!! Thank You.. Heres My code Dim theElementCollection As Windows.Forms.HtmlElementCollection theElementCollection = Form1.WebBrowser2.Document.GetElementsByTagName("a") For Each curElement As HtmlElement In theElementCollection Form1.DataGridView1.Rows.Add(curElement.GetAttribute("title"), …

Recently, I've been writing some sort of thesis. Mostly a study note, for helping me (and others) with architecting a program because all those confusing and complicated concepts. I'd like some peer reviews, because most of the material in the are based on ideas rather than practical experience.

Hello, I am facing a problem I cant seem to find an efficient solution for. My application is supposed to parse a text file while another process is continuously adding to it. I have tried scanner and inputstream but both seem to stop once they hit the end of the …

Hi, I got multiple threads in different classes created in this manner: private ThreadStart someName_TS; public Thread someName_Thread; public void someName() { someName_TS = new ThreadStart(someNameThread); someName_Thread = new Thread(someName_TS); someName_Thread.Start();} } private void someNameThread() { while(!Shutdown) { //Do heavy work } } The heavy work is set to a …

Alright this one has me stumpted. I have a piece of code to do TCP Listening running on a thread that was executed from the ThreadPool, using this little one liner `ThreadPool.QueueUserWorkItem(ServerListener);`, that will continue to run until a status flag is altered. When the thread has ended I need …

Hi Dw. I'm deeply in need of your help, I'm having a problem that is giving me a very serious problem with my code. My program is a multithreaded program and its a TCP/IP based application. Client has no problem, only a server that is being so weid to me …

Recently I started using my first attempt at Python multithreading. The purpose of the code is to run multiple WHILE loops at the same time, one of which searches for the change of a variable to TRUE caused by input picked up by the other. However, when i ran the …

Hi All, In below code snippet multithreading is used to take care of multiple requests from client. I beileve creating and detaching thread will eat lots of CPU cycle and it won't improve the CPU utilization as well. Can anybody let me know if thread pool can be used here …

Hey, I have been reading Java oracle tutorials. I read this thing. Suppose, for example, class MsLunch has two instance fields, c1 and c2, that are never used together. All updates of these fields must be synchronized, but there's no reason to prevent an update of c1 from being interleaved …

Hi Dw. I am developing a client server multi-thread application. This application uses signals(certain messages as signals), in order to perform a task for a client. For instance if a client wants to login, the client send a message as: `Login:<username>:<password>` and on a server I first check if the …

i need your help please i need to create a loop for thread that does the following 1.thread for each number in the list box 2.Each thread calculates the Fibonacci number of the item that it is assigned to When the thread finds the Fibonacci number, it automatically adds it …