JuliaLang/julia

add `Threads.@once`

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#51,716 opened on Oct 15, 2023

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 (9 comments) (1 reaction) (0 assignees)Julia (5,773 forks)batch import
good first issuemultithreading

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Description

It might be useful to have a Threads.@once macro that guarantees a line of code will only be executed once, either globally or in a given scope, a la C++ call_once or GCD dispatch_once

Contributor guide

Research direction
Study existing Threads macros like @threads and @sync, then design and implement a @once macro using a global or per scope flag with thread safe initialization.
Tech stack
None
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JuliaGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75