Questions tagged [multithreading]
Use this tag when the program performs its work using multiple concurrent threads of execution.
1,589
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c++ multithreaded message broadcaster with link lifetime management v3
note: This is v3 of code that was previously reviewed.
I have written a class that handles listeners registering callbacks to receive messages. Link lifetime is managed (or is it? See below). Code is ...
4
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1
answer
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Use a static field for cache an authentication token in .NET API
I have a .NET 6 web API that does some requests to another third party API, this API has a token that expires after a few hours, so I want to cache this token and reuse in the requests.
Here how I ...
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3
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1
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A mutex that can detect certain types of programming error
This mutex prevents concurrent access to a target resource. One key requirement is the ability to be acquired
in a (scheduler) thread and released in a different (worker) thread. Unfortunately this ...
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2
votes
1
answer
117
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Multithreaded segmented Sieve of Eratosthenes
I am fairly new to Rust and thought a good way to practice would be to write a multithreaded segmented Sieve of Eratosthenes. It performs ok (searches ten-billion numbers in about 11 seconds on my ...
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2
votes
1
answer
60
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Force acquiring R/W lock
I am trying to build an abstraction that forces lock acquisition before data can be accessed.
This seems to work, but please tell me if what I am doing horribly wrong, and what I could improve.
I am ...
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1
vote
2
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93
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multithreading LRUcache in C++
I want to implement a multithreading LRU cache in C++. And here is the code. Can you tell me what should I do to make it more multithreading?
...
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3
votes
2
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105
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Fast portable, parallel MSD radix sort for unsigned keys in C89
Now I have this portable, parallel MSD radix sort for unsigned keys. It exhibits linear speedup on small values of \$P\$ and has a running time of
$$
\Theta(N/P + P)...
- 27k
4
votes
2
answers
805
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Traffic simulation GUI: an exercise in concurrent programming using threads
To avoid a code dump I have removed most of the code and left the first few lines of constructors and methods and anything relevant. Full code at the bottom.
The purpose of this code is to use threads ...
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1
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1
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114
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Timeit multithreading/multiprocessing C++
Given a Timeit method which runs for n times the provided function, which approach between multithreading and multiprocessing should be better to speed up the execution of all iterations and avoid the ...
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2
votes
2
answers
242
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the multi-threading of adding all the values from a random generated vector
I currently am creating a vector and fill it with random values( for this case the random values will be 1) once the vector is created i want to calculate the total sum which should be 100000000, I am ...
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0
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182
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Design a thread-safe Hit Counter
I have designed a Hit Counter which can conveniently be used to design a Rate Limiter
Original question: https://leetcode.com/problems/design-hit-counter/
To make it thread safe, I used lock statement....
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4
votes
1
answer
222
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Multithreaded MVC game engine
This is an attempt at a multithreaded model-view-controller based engine for 2d console games (board games, roguelikes that sort of thing.) The code below will provide a fully working example but is ...
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2
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1
answer
152
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Card game simulations, with a multithreaded version slower than the single-threaded one
I'm new to rust and I'm trying to build a card game simulation to find all of the best actions with all possible hands. This requires a lot of simulations and my first 3 million are already taking a ...
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2
votes
1
answer
250
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Thread scheduler in C
I have made a simple round robin scheduler that switches between threads in ptable array. Currently it's only for 1 CPU, so there are no locks at the moment.
But ...
4
votes
1
answer
2k
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Timer thread implementation
I've implemented a timer thread whose job is to call functions at a certain interval. The functions may be called multiple times if their interval > 0 millisec otherwise only one time. Even if the ...
2
votes
1
answer
92
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Monitoring webpages to be notified
I have been writing a monitoring script where I check for whenever there is changes on a webpage. When a change has happend I want to be notified by printing out that there is a difference.
I have ...
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2
votes
1
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141
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Priority Job/Task Queue for Linux (sockets and multithreading)
Preface
Please review my implementation of a job queue for linux/unix systems. This is my first time coding in C, although I have quite some experience in C++.
I know this is a moderate amount of loc, ...
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3
votes
2
answers
195
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Thread-safe cached compiled Regex
I have a use case where I want to keep a pre-compiled regex, cached, for performance reasons, but the regex pattern also needs to be updated infrequently. Instances of CachedRegexFilter class will be ...
- 415
2
votes
1
answer
95
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Compare between two dictionaries
Hello beautiful people!
I have currently worked on a small script that I would of course continue to work with whenever I get a good feedback from the best code reviewer in here <3 - I have worked ...
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4
votes
2
answers
142
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Simple multi-threading setup for tile rendering (C++)
I am writing a small framework that I intend to build upon in the future. I am also using this framework to teach people how to support multi-threading in 3D rendering, and thus wanted to be sure I ...
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vote
1
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149
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A C++ Job Manager Class (Rev 1)
This is a revised version of the JobManager class originally posted here. The revisions made were centered around:
Encapsulating the ...
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4
votes
1
answer
118
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Task executor thread pool
Despite my experience with Java, I am not well-versed with concurrency. I wrote this thread pool that has a queue of tasks. Please ignore any signature choices, such as overuse of ...
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3
votes
2
answers
116
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Ball movement within an area
I was asked to write a code in C++ using threads, in which I have to have two limits and 4 characters. Characters can go inside the area limited at the same time when they approach from opposite sides....
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1
vote
1
answer
232
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NTP client displaying reference, originate, receive and transmit timestamps periodically with graceful shutdown in C#
based on this stackoverflow topic: https://stackoverflow.com/a/12150289/15270760 I have decided to create a simple NTP client displaying difference between NTP server response and DateTime.Now called ...
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1
vote
1
answer
465
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Multithreaded observer pattern in Rust
I often want to program in an event driven way, but classic implementations of the observer pattern often pose an ownership challenge, and they only get more difficult once multiple threads are ...
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3
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2
answers
1k
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Multithreaded tcp server accepting two clients with task factory and graceful shutdown
as an exercise from multithreading and networking I have decided to create my own implementation of TCP server accepting connections from two clients (which is I think a pretty common case e.g. chess ...
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1
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0
answers
2k
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Implementation of Concurrent List in .NET
I would appreciate review of this implementation of the concurrent list that is, to my knowledge, currently missing in .NET Core.
Requirements
Thread safe
Lock free
Ordered
Supports get and set by ...
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2
votes
1
answer
2k
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C++20 Multi-queue Thread Pool with Work Stealing
This is a follow up to my previous post which also follows up on my first post regarding my thread pool implementation. I have since made some further changes and attempted to improve performance with ...
- 420
3
votes
1
answer
275
views
Golang function that reads S3 files and populates maps with strings as keys
I have a below read function which is called by multiple go routines to read s3 files and it populates two concurrent map as ...
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4
votes
2
answers
329
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Multi-threaded Mandelbrot set generator slower than single thread
I am new to parallel programming. I have been playing around with multi-threading and for some reason, multi-threading the Mandelbrot set is slower than running a single thread. I have been trying to ...
- 41
1
vote
1
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451
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Thread in a Spring app that watches a directory for new files
Before showing-off the code, here is a bit of an explanation.
I have a Spring component that spawns a thread for watching a directory for new files.
In this context, I have a method that runs in a ...
1
vote
0
answers
462
views
TCP socket management using multiprocessing
I wrote a Python code for a device that generates an hotspot and communicates with an app using a TCP socket. The communication is managed by a process that opens a socket and uses two threads to send ...
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9
votes
2
answers
961
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Multithreaded bogosort in Rust
For some quick context, I'm fairly new to Rust and decided to give myself a difficult-but-attainable task of implementing a sorting algorithm. I chose bogosort (or stupid-sort, shuffle-sort, whatever ...
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0
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43
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Python scraper that gets product information from e-commerce website
I have built a scraper that scrapes data from e-commerce website and saves it to json using my own module. Although, I made the scraper multi-threaded, it starts slow, then speeds up and uses a lot of ...
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2
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1
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3k
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tiny thread pool implementation
I wanted to write a minimal thread pool implementation.
You can submit tasks and get a future.
When the pool goes out of scope, all pending tasks will complete and join all workers.
In an earlier ...
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1
vote
1
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326
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Low-Latency Multithreaded Logger
My goal was to have a logger that does the blocking file I/O in a separate thread.
A few notes:
I made it a singleton rather than having a global "logger" variable, or a bunch of loggers ...
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1
vote
1
answer
113
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multiply matrices
I wrote a program that calculates the multiplication of two matrices (of compatible dimensions) where each element of the resulting matrix is calculated by a separate thread. Each thread calculates ...
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2
answers
1k
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C++ thread pool and thread safe queue
This is my first time writing a custom thread pool in C++. I would love some feedback on how my code looks and if I am missing best practices or have glaring/subtle issues. Thanks!
ThreadPool.hpp:
<...
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1
vote
1
answer
71
views
Re-usable worker pool classes
I am trying to read multiple files in parallel in such a way so that each go routine that is reading a file write its data to that channel, then have a single go-routine that listens to that channel ...
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2
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A multithreaded implementation of the 'which' command
Here is an implementation of the 'which' command which can tell where programs are located.
...
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1
answer
2k
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Collect and combine results of async calls returning completable futures in Java in a cleaner way?
I need an abstract way to implement this below functionality because in my code I have to use it in multiple places with different REST endpoints. If I ignore it will cause code duplication.
Please ...
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votes
1
answer
245
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Python asyncio multithread wrapper
For my application, I needed a lightweight way to launch multiple tasks and monitor their completion in a main loop periodically or use callbacks. The main loop is going to be busy most of the time ...
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5
votes
2
answers
1k
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C++20 Single Queue Thread Pool
This is a follow up to my previous post. I've made a number of improvements to the thread pool and corrected some bugs as well.
The most up to date version of the code is available on my Github.
I ...
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4
votes
1
answer
948
views
Simple parallel compression using Run-length Encoding in C
I encountered the concurrency-zip project in OSTEP By Remzi Arpaci-Dusseau. So basically, I've built a simple compression program that uses Run-length Encoding, and multi-threading in C. But I couldn'...
2
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0
answers
113
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C++ logger for Windows
I have written a simple logger in C++ on Windows that I want to use to log info and errors from multiple threads to DbgView:
...
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5
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3
answers
2k
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Least Recently Used Cache with TTL
I found this problem in a book and found it interesting. wrote this class to implement a Least Recently Used Cache with TTL.
Goal -
LRU cache with TTL
Multithreaded.
Functions: Get(key), Put(key,...
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votes
2
answers
3k
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C++ Thread safe priority queue implementation
My first attempt at writing a thread safe priority_queue. It is not the most efficient because the locks can be even more fine grained if I add implementation of heap instead of using priority_queue ...
- 223
1
vote
1
answer
177
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Bank account concurrency problem Swift
I tried to implement a simple BankAccount class to practice providing a solution to the common Bank Account transaction data race problem. Reference to a description of such a problem can be found ...
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2
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1
answer
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C++14 Lock-free Multi-producer, Multi-Consumer Queue
Introduction
This is a follow-up to a previous question of mine, where I presented another queue of the same type to get some feedback on it. Some people pointed out some fundamental errors I had ...
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4
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1
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206
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Task manager object for lazy initialization
The Problem
I am developing a Visual Studio extension for importing code from a server.
Because of the way Visual Studio works, multiple threads could try to perform the same operation at the same ...
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