# How to do an atomic compare and swap on a SharedArray

**URL:** https://discourse.julialang.org/t/how-to-do-an-atomic-compare-and-swap-on-a-sharedarray/91942
**Category:** General Usage
**Created:** [December 21, 2022, 10:52am UTC](https://discourse.julialang.org/t/how-to-do-an-atomic-compare-and-swap-on-a-sharedarray/91942 "2022-12-21T10:52:24Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Impressium](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/impressium/32/19575_2.png) [@Impressium](https://discourse.julialang.org/u/Impressium)
#### Post date: [December 21, 2022, 10:52am UTC](https://discourse.julialang.org/t/how-to-do-an-atomic-compare-and-swap-on-a-sharedarray/91942/1 "2022-12-21T10:52:24Z")

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Hi all 🙂

I want to use shared memory and do an atomic\_cas! (Atomically compare-and-set) in some file/ shared array. How would I do that?

Thanks!