Questions tagged [thread-safety]
A piece of code is thread-safe if it only manipulates data structures in a way that allows consistent execution of this code by multiple threads.
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Testing an unsafe counter
I made this studying my Java book about concurrency. It's just to test. I feel it works ok but I'm not so sure about my Java. I worry maybe my code style is strange. I really didn't want that ...
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Counter GUI in Swing, updating the count in the background
I made a simple counter GUI for practice. The user presses a button to start the counter. The button click executes a SwingWorker task that updates a JLabel with ...
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Thread-safe Shared Pointer implementation in C
I've been working on a C project where I needed a small, thread-safe shared pointer, and so I wrote this implementation.
It's primary use in the project is as a way of allowing multiple threads to ...
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C++11 lock free collection similar to std::forward_list - follow-up 2
Thread safe and lock free collections are very hard to write, so I'd appreciate any feedback, especially regarding bugs. The code below is a self contained hpp, followed by some tests.
This question ...
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Execute a list of Threads in parallel
I have a list of Script that i want to execute them in parallel, i already find this way in Creating dynamic number of threads concurrently, so i use this piece of code here :
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AntiCSRF: simple CSRF token management for server APIs
I've been working on a full stack web application for a school project, and I wrote antiCSRF without prior experience or example code to prevent Cross-Site Request Forgery attacks, and to ...
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Notifying consumers when a producer is done
I am writing a simple program with a producer and a few consumers: the producer pushes to a queue some integers, and the consumers pop elements from the queue and print them (order doesn't matter). ...
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Thread safe static collection, is this code safe
A small caching utility, can you tell if it is thread safe?
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Exercise – Synchronization between threads using `pthread_mutex_t` and `pthread_cond_t`
I have got an assignment for an OS course that consists in the use of mutex and condition variables to synchronize N threads, each involved in the search of a character in a row of a NxN matrix.
The ...
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Create PDF preview
I have written the following GetPDFPreview() method. It open a PDF file, create a thumbnail (using PdfDocument class) and ...
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Polling an API endpoint with timeout using channels
I have written a simple API client for my app in Go.
The client is very simple, it wraps http.Client and has some convenience methods.
The one method I am trying to get some feedback on, does ...
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Sending a string from anonymous thread to UI with PostMessage
I am sending a string from an anonymous thread to the UI with PostMessage in the following code:
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Recursive shared mutex
I've been looking for an implementation of a recursive shared mutex to handle a very special data tree inside a heavy multi-threaded application.
Because boost and ...
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Implementing a thread-safe LRUCache
Here is the problem I've been trying to tackle:
Design a thread-safe image caching server that can keep in memory only the ten most recently used images.
I chose to implement an LRU cache to solve ...
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ASP.NET Core singleton acting as an HttpClient provider
I have created an ASP.NET Core singleton service class to act as an HttpClient provider after reading that reusing an instance of HttpClient is encouraged. However, I also want to be sure that the <...
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Singleton implementation of a database connection
I have implemented as follows, a class applying singleton pattern to get a global single access to database.
I intend to provide a thread-safe implementation.
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Static ConcurrentDictionary to maintain static objects
I am using following code to maintain some static information. The problem I see with it is that, if the information retrieved using GeKeysFromCache is modified without using lock keyword it may lead ...
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Throttling class
The idea of this class is that several threads are sending data over a network and each thread are sharing the same instance of this class and before sending N bytes over the network each thread is ...
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Accessing SQL stored procedures
The following code is from the DataAccess layer that calls the SQL stored procedure and returns the result set back to the calling code.
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Concurrently reading a Map while a single background thread regularly modifies it
I have a class in which I am populating a map liveSocketsByDatacenter from a single background thread every 30 seconds inside ...
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Locking in MySQL stored procedure for deduplication
Multiple upstream servers are sending notifications to a load-balanced django app. If all the upstream servers are working correctly, the app will always receive duplicates of these notifications (...
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An improved single instancing library
I previously posted a question: Single instancing class and received some good feedback on it.
I have implemented most of the changes suggested by @EBrown.
I also implemented the suggestion by @...
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Simplified LogService (from concurrency in practice) with shutdown feature
Brian Goetz provided following code of LogService with shutdown feature:
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Partition numbers as polynomial, each number in a thread
I'm beginner at multithreading programming and I wanna write a piece of my code using it. I'm trying to split different numbers into multiple parts and store them as a polynomial. I wanna do this ...
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Asynchronous service that publishes a possibly infinite amount of events
I want to implement a service that fetches eyetracking events and publishes them to all subscribers of the stream. The whole thing is supposed to run asynchronously, so it doesn't block the UI thread. ...
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Running multiple producer and single consumer in a multithread environment
I have a below class in which add method will be called by multiple threads to populate messageByChannelReference concurrent ...
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Multi-threaded code to handle messages from a provider
Having a look at my code, is there a way to be losing elements?
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Synchronization of transaction processing
There's a server which does the following:
Receive request with transaction id
Load corresponding transaction from storage. New transaction object is returned each time
Process transaction
Save ...
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Insert and Remove Element in Deque using threads in C++
The following code works fine for inserting and removing an element from a deque using two threads.
I would appreciate any help on how to make it better, especially in terms of thread safety.
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Thread Safe File Operation
I am trying to make file read and update operations thread safe and prevent race conditions in Python. Am I missing out something, or would this work in production?
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Writing a thread-safe queue in C++
I created a SafeQueue class, which stores pointers. It has two methods:
push: Adds a new pointer to the queue
next: If the queue is empty, returns nullptr. ...
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Thread safe singleton class to connect to Cassandra
I am working with Cassandra and using the Datastax Java driver for it. Here is my singleton class where it makes a connection to Cassandra:
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Which CountHolder implementaion is thread safe? [closed]
Is it sufficient to only synchronize the incrementCount?
Is it possible for all other threads to get the updated value all the time?
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Caching all the prepared statements in thread safe way
I have a below Singleton class where in my getStatement method, I populate a CHM by doing if check.
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Header only c++ singleton pattern implementation
I want to implement the singleton pattern in a header only c++ library. (Please refrain from sharing your opinion on the pattern itself!) This would be trivial if I could rely on the compiler ...
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Executing an SQL command on a number of files
Is this thread safe?
I have a program that executes an SQL command on a number of files (selected by the user).
Here is where I create the threads:
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Read and write in C# buffer in parallel
I have a buffer - int array with defined length. I want to read and write values into this array in parallel. For instance, 5 readers and 3 writers with different ...
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Constant keys thread safe dictionary
I find that I use this pattern a lot where I have a dictionary which I would only read from and update and wouldn't add/remove keys.
In that case, using ...
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C++14 Thread Pool
I have written the following thread pool implementation in C++14.
It appears to work fine on my system, but I am looking for a second opinion on the thread safety of my implementation and any other ...
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Basic memory pool, alignment, thread safety
Mainly for practicing purposes, I'm trying to implement a simple, yet efficient memory pool. It's basically a linked list that is able to grow, with fixed sized members. Each node has a flag if it's ...
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Semaphore implementation by file locking in a bash script
This implementation is inspired by the POSIX functions sem_wait() and sem_post(). It tries to get rid of busy loops in the code ...
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C++ 14 thread pool executor design
With a few experience of python and golang, I tried to make (simple) thread pool executor. Tasks of the executor must be copy-...
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Thread safe Pooled Dictionary
I have an object that is fairly expensive to create and has a tendency to get created multiple times because each distinct user may have one or many instances of this object. This object can expire as ...
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Blocking and non-blocking queue
I came up with the following for a blocking and non-blocking queue implementation. Please suggest any changes/improvements/gotchas.
Blocking queue:
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Synchronize different tasks (I/O listening daemon, prompt scheduler, output etc)
Shortly, I need to create a Java application with client/server architecture (clients represent some sort of math functions and when they are done computing, server consumes these values and produces ...
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Threadsafe filtering queue
I have implemented a thread safe filtering queue. The queue allows any objects, of the specified type to be added. A thread interested to take an object must specify which object it is interested in ...
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Thread-efficient nonce generations
I need to create unique nonces for cryptographic purposes in a library that I am writing. If the nonces ever fail to be unique, the consequences may be up to and including remote execution of ...
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Single-threaded timer
I've created a System.Threading.Timer wrapper in C#. The tasks to be triggered when the timer elapses have highly variable execution times. My design criteria are:
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