Questions tagged [multithreading]
Use this tag when the program performs its work using multiple concurrent threads of execution.
1,588
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Counting unfair semaphore implementation in Java [closed]
I am implementing Java's Counting Semaphore's acquire() and release() methods and using it in a multi-producer-consumer problem.
Semaphore class
...
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2
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0
answers
11
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Recording/Playback thread device in Object Pascal
I have developed an audio recording and playback base device in Free Pascal. This device is built on Free Pascal's TThread class and utilizes the low-level audio ...
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4
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2
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76
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C++ Neuron Spike Raster Deserializer
Please help me establish a solid foundation for this computational neuroscience project. I'd like to make sure I'm moving forward with something reasonable before I begin tackling the more complex ...
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0
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43
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Optimizing tokio and pcap Operations in Rust for Max Throughput
Background
I'm mostly a c# and python programmer and am slowly learning Rust. I'm not sure if that is contributing to incorrect concepts as to how threading and io work in Rust, but that's what I'm ...
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5
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1
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365
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Print abcabc... in three threads
I want to implement the following case
Input - integer number n
Start 3 threads. The first thread prints 'a', the second prints 'b', the third prints 'c', then the ...
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4
votes
1
answer
96
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Packet generation and consumption
I have the following simplification of a program which consists of 2 threads. One thread pushes packets to the back of a deque while another waits for user input before performing a "heavy" ...
- 359
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0
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34
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Handling a subprocess' output in background threads and accepting user-provided sinks for the output
I have a PR swapping from Command::output() to a custom implementation using threads to handle the subprocess' stdout/stderr while the program is running, instead ...
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0
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100
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For loop vs If statement using conditional variable
I'm extending the sync.Pool type by limiting the amount of objects that can reside outside the pool. To achieve this I'm using ...
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2
votes
1
answer
181
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Parallel handling db queries is very slow in C#
I have SignalR app that publishes sent messages to Redis. My console app subscribe to channel where these messages are sent, deserializes it and saves in database.
Problem is with handling these ...
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2
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1
answer
98
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C++: algorithm that uses fixed-size buffer of data that are produced in stream, faster than the algorithm speed; modified version
This is a, I hope, an improved version of this code, limiting atomic usage (following @GSliepen, @G.Sliepen advice) (NB I'm limited to, at most C++17):
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7
votes
1
answer
960
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C++: algorithm that uses fixed-size buffer of data that are produced in stream, faster than the algorithm speed
I try to implement this scenario with a producer/consumer multithread pattern and I'd like to optimize synchronization and memory model directive used.
This code originates from a SO question and its ...
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5
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3
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2k
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An exercise in Data Oriented Design & Multi Threading in C++
Been working in games development professionally now for about ~5 years, but have only been doing OOP & haven't worked with multi threading before as I'm mostly a gameplay programmer, I've also ...
2
votes
1
answer
62
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Single worker, multiple async callers in different threads
My use case is this:
There is a long running process that I want to ensure is only ever running at most only a single time.
Multiple consumers from different threads may wait on the calculation.
If ...
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2
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85
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Web scraping spider
I'm currently working on my first web scraping project and I need to scrape a lot of websites. With my current code it takes more than a day but for my project I need to scan the same websites every 5 ...
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0
votes
1
answer
120
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C++ slim condition notifier
When writing multi-threading code, one often need the thread to wait for some condition being met. A naive approach would look like this:
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4
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2
answers
118
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Get files downloaded asynchronously after double clicking on list item (C++)
The problem I am trying to solve as an exercise is as follows:
I have a UI running in the main thread, specifically a list view with many items. Each item represents a file that the user can download....
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3
votes
1
answer
74
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Parallel semi-sequential bottom-up tree traversal algorithm
I'm trying to traverse a tree-like structure from the bottom-up, and in parallel. Due to some other constraints I also have to allow for thread counts that may be lower than the width of a given set ...
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1
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1
answer
103
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Multithreaded O_DIRECT file read-and-process program
Here is my code. It reads a file and returns the sum of all the bytes in the file:
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0
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50
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A parallel MSD radix sort in Java for integer keys
I have this repository: https://github.com/coderodde/ParallelRadixSort.java/tree/main
It contains a parallel MSD radix sort presented below:
...
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37
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Trait to extend iterators with parallelized mapping function
Working on a project of mine, I wanted to parallelize mapping operations on an input stream. I found pariter on crates.io but it did not fit my needs, because its generic's bounds require the iterator ...
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3
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2
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459
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New York Times' Digits Game Solver
I wrote an algorithm to solve the New York Times' Puzzle: Digits.
You could play the game here.
The rules of the game are as follow:
You were given 6 numbers and you could use simple operations (plus, ...
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1
vote
1
answer
65
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Rate-limited thread scheduler in Java
Background: I'm planning to call different endpoints of a website's API quickly, but the usage policy implies that I may only make five calls in a second. I can't rely on the calls taking 200 ms on ...
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2
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1
answer
105
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Parallelization of the tick function in a Game of Life simulation using Rust and Python (+ NumPy)
I've been writing a small Rust module recently with the sole purpose of speeding up my Python program, which is a Conway's Game of Life simulation. The function written in Rust is called from Python ...
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1
vote
1
answer
90
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C++ Dynamic Balancer on a Threadpool
I have a Balancer Class in my project which should dynamically increases/decreases the amount of Worker Thread based on the current amount of Messages which are ...
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4
votes
2
answers
1k
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Multi-threading Class in C++
I wrote a C++ class which can take a vector of functions and their respective arguments and execute them in parallel and return a vector of results from its respective functions.
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4
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1
answer
309
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Threadsafe Non-Overlapping Timer
I was working on a project recently, where I needed to process some tasks periodically, but the execution of those tasks could not overlap with one another. ...
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2
votes
2
answers
161
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Code for asynchronous data stream processing with multistage pipelines
I am trying to write some code for processing streams of asynchronous data from multiple sources (Producer Nodes), process them ...
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6
votes
1
answer
347
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Synchonizing queue with mutex
I am trying to syncronize the queue between threads using mutex. I have 2 mil random integers in input.txt file. Main thread reads integers then puts them in queue. Other threads are simultaneously ...
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3
votes
1
answer
226
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Multithreading a shortest path algorithm
I would like to modify my shortest path finding code to use multithreading and improve its performance. The algorithm must be able to work with negative weights, and as a result, we cannot use ...
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6
votes
2
answers
818
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C++ Thread Pool Implementation using Lock Free Queue
Topic: C++ Implementation of Lock-Free Queue and ThreadPool classes
In a project I'm currently working on, I need the implementation of ThreadPool along with a thread-safe queue. I've tried ...
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4
votes
2
answers
188
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Multithreaded Conway's Game of Life implementation written in C and Java using JNI
I had some multithreading C programming experience from school last year but I wanted a bit more so I tried to program a Conway's Game of Life implementation from scratch.
Code is mainly written in C ...
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0
votes
1
answer
116
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Lock-free implementation of getAndUpdate() using atomic CAS (Compare-And-Swap) operation
We have the following class written in Kotlin Native with the new Memory Manager (which doesn't require to freeze objects):
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7
votes
2
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783
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ThreadSafe std::queue
I have written a threadsafe queue and I would like you to suggest what can be improved and how to write good unit tests for this implementation.
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1
answer
2k
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Safely starting and stopping a thread owned by a class
If I have a class running its own thread, I almost always try to write it like the following, with the thread started by the constructor. The reason for this is that an object can never be constructed ...
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7
votes
1
answer
216
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C++ mutex-like class using std::condition_variable
On a project I'm working on, I have a need for a mutual-exclusion primitive behaving like std::mutex or std::recursive_mutex, ...
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2
votes
1
answer
116
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DFS Maze Solver
I am new to Rust Programming so I decided to implement a Maze Solver using DFS. I was wondering if there is any way to optimize this code further
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1
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81
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Training a Reinforcement Learning algorithm
Problem:
I'm trying to reduce the computation time and optimize specific functions of a Reinforcement Learning algorithm in the training phase and observed that one block of code takes too much ...
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3
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1
answer
321
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jthread drop-in replacement
I have a couple of libraries that use jthread, but also are published via vcpkg. The problem I have is that both github and vcpkg's AzureDevOps CI have a version of clang that does not have jthread ...
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4
votes
2
answers
230
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Multiplayer queue optimisation
I currently have code that is working but I think it can be optimised.
The code waits until a player joins and adds the player to a BlockingQueue if there is
not already a Player waiting then it ...
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1
vote
1
answer
150
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Dining philosophers problem using just lock without semaphore in C#
I am trying to solve the Dining philosophers problem in CSharp. I didn't use any semaphores and it looks like it's working. I am wondering 1) if my code deadlock is safe and 2) if can I please get ...
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2
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389
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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 ...
3
votes
1
answer
1k
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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
answer
122
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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
106
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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
57
views
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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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
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2
answers
99
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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
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2
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676
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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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104
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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
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2
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204
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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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