141,057 questions
-6
votes
0
answers
73
views
Undesired Pulsating in Rendering and Cumulative Slowdown When Implementing Fixed Physics Timestep in Multithreaded Physics [closed]
INTRO
I am getting unwanted pulsing and slowing down in rendering 2d particles, which should be drawn faintly (low alpha) and leave a fading trail under the influence of gravity. Below is a ...
- 18.6k
0
votes
0
answers
17
views
Actix-web + Tokio: Server hangs when using tokio::spawn with Arc<Mutex> loop
I am facing an issue where my Actix-web server starts correctly, but the moment I hit the /upload_chunk endpoint from my frontend, the request hangs forever.
After some debugging, I found that the ...
- 51
1
vote
0
answers
111
views
How is a non-parallelized for loop inside an OpenMP parallel section executed?
Consider the following code:
#pragma omp parallel
for (int run = 0; run < 10; run++)
{
std::vector<int> out;
#pragma omp for
for (int i = 0; i < 1'000'000; i++)
{
...
}
}
...
- 7,475
Advice
1
vote
13
replies
104
views
C# - lock multiple methods or entire class to single thread execution
I am trying to ensure that methods in my class can only be called by a single thread.
So far tried to use ReaderWriterLockSlim to achieve this effect but this can cause potential issues if it is not ...
- 33
4
votes
4
answers
571
views
Pure Swift concurrency [closed]
All the libraries I have come across that provide Swift concurrency functionality either depend on an Objective-C library or are wrappers around the C based GCD. (iOS and OS X)
I'm just wondering if ...
- 35.2k
Best practices
0
votes
3
replies
64
views
Is there anyway to get physical disk Idle time without 1 second wait needed for PerformanceCounter.NextValue function?
I trying to develop user-friendly program that do not block physical disk with 100% usage (so even entering My Computer takes around 10 seconds).
My program calculate hash for many (180k) small files ...
- 10.1k
0
votes
2
answers
121
views
compare_exchange_strong failed to update the expected value
I am trying to implement a lock-free multiple-producer-single-consumer ring buffer in C++. Here is the full definition and the test code.
#include <iostream>
#include <memory>
#include <...
- 783
232
votes
5
answers
173k
views
Are lists thread-safe?
I notice that it is often suggested to use queues with multiple threads, instead of lists and .pop(). Is this because lists are not thread-safe, or for some other reason?
- 3,257
0
votes
1
answer
315
views
Can external IO operations be considered as if seq_cst operations in the reasoning of multithreaded programs?
Consider this example:
// thread A:
start_transaction();
update_mysql();
commit_transaction(); // remove "key" from mysql tables
remove_redis_cache("key");
// thread B:
std::...
1
vote
1
answer
126
views
Why does my multithreading/pointers code print random values?
My code should print the numbers given as command line arguments. Instead it prints random-looking values.
What is going on and how can I fix it?
#include <stdio.h>
#include <pthread.h>
#...
- 16.4k
2
votes
1
answer
63
views
Opening a pop-up window when error from a worker running in Qthread occurs completely freezes the program
I was trying to create a little Python program with a GUI using Pyside6. I ran into a problem when creating a thread for a worker to do a task (check files with a certain condition and then copy them ...
- 4,939
0
votes
0
answers
250
views
multithreading java and neural network : reading 2 csv files at the same time
I'm working with a neural network project that requires to run two instance of the neural network program with different training set specifically two at the same time. For that I'm using ...
- 3,660
21
votes
4
answers
18k
views
main.async vs main.sync() vs global().async in Swift3 GCD
Example A: This causes the app to crash.
DispatchQueue.main.async {
let url = URL(string: imageUrl)
do {
let data = try Data(contentsOf: url!)
DispatchQueue....
- 35.2k
0
votes
0
answers
106
views
How efficient are pipes and threads in C compared to regular function calls or pure sequential code? [closed]
I’m currently studying Operating Systems at college, and my professor has started teaching us about threads and pipes in C.
His teaching style is very practical — he expects us not only to understand ...
10
votes
2
answers
8k
views
Thread BLOCKED on org.apache.log4j.Category.callAppenders, but not waiting for any lock
My web application(delpoyed on weblogic) went down, when I check the jstack info, I found most threads are BLOCKED on a org.apache.log4j.spi.RootLogger. The thread owning this lock is also BLOCKED and ...
CommunityBot
- 1
855
votes
26
answers
414k
views
What is the volatile keyword useful for?
I came across the volatile keyword in Java. Not being very familiar with it, I found this explanation.
Volatile variables are a simpler -- but weaker -- form of synchronization than locking, which in ...
- 35.2k
4
votes
1
answer
699
views
Multithreaded Server with AsynchronousServerSocketChannel
I have to implemented a server which should accept more connections. Without any deeper thoughts I decided to use the new JAVA NIO.2 classes.
My current approach is:
final Semaphore wait = new ...
- 3,660
48
votes
2
answers
17k
views
Is there a way to have a Rust closure that moves only some variables into it?
I have a general struct with settings and an extra variable setting that I want to tune and play around with.
For all possible values in an integer range, I want to start a (scoped) thread with ...
- 158k
0
votes
2
answers
59
views
Calculate byte positions to split ndjson files into chunks
Below is the code extracted from this repo:
import os.path, io
filename = ""
n_chunks = 12 # Number of processes to use -- will split the file up into this many pieces
def ...
- 24.1k
8
votes
4
answers
5k
views
C++11: Is std::thread on linux depending on pthread library?
I read that pthread is C library and is not compatible with C++ object model, especially when talking about exception handling.
So I wish to know on linux system, how gcc/clang implements std::thread,...
- 138k
0
votes
0
answers
43
views
How to set up multi-thread logging to different loggers using QueueListener and QueueHandler
I have a Python application that runs multiple tasks in parallel using ThreadPoolExecutor. I want all threads to log safely without race conditions. I also need two loggers:
Console logger (prints ...
- 35
0
votes
2
answers
10k
views
Multithreaded file copy for Linux needed
I have a "large" amount of data that needs to be copied every day. (6TB)
It is 15 disks presented from a SAN over Fibre Channel and being copied to a local array consisting of 22 spindles.
sources ...
CommunityBot
- 1
5
votes
2
answers
25k
views
Specify default MaxDegreeOfParallelism in Parallel.ForEach?
We would like to optionally control the number of "threads" on our parallel loops to avoid overwhelming a web service (for example).
Is it possible to specify a custom MaxDegreeOfParallelism on a ...
- 46.1k
1
vote
2
answers
2k
views
python asyncio: how to best use lock threads?
Let's imagine I have a thread with an asyncio event loop and other threads running.
I may have to deal with synchronisation between threads with the lock mecanism for instance. But the lock may block ...
- 506
8
votes
4
answers
10k
views
Loading Ad (adMob) on Background Thread
I want to load my add on a background thread cause it makes the SlidingMenu laggy upon opening and closing. Should I use a Thread/Handler? Or AsyncTask?
String MY_AD_UNIT_ID = "----";
AdView ...
- 495