# Mogelijke Race Condition bij het bewerken van een bericht
**URL:** https://meta.discourse.org/t/possible-race-condition-when-editing-a-post/177514
**Category:** Bug
**Created:** [28 januari 2021 om 03:58 UTC](https://meta.discourse.org/t/possible-race-condition-when-editing-a-post/177514 "2021-01-28T03:58:29Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@concerto](https://meta.discourse.org/u/concerto)
#### Post date: [28 januari 2021 om 03:58 UTC](https://meta.discourse.org/t/possible-race-condition-when-editing-a-post/177514/1 "2021-01-28T03:58:29Z")
## Problem
Concurrent edits to one wiki page can lead to unexpected behavior. In my case, the `quoted_posts` relationship between two post becomes wrong.
This may leads to other problems when `quoted_posts` is used, like in User#refresh\_avatar. The missing `quoted_posts` makes it unable to rebake all quoted posts.
## Possible Cause
The warning introduced by this [commit](https://github.com/discourse/discourse/commit/f60b10d090171c49134b20abcfb089ebb94fad21) is not enough to safeguard concurrent edit to a post, as the check is not atomic. This is a rare situation but it still can happen.
`PostRevisor#revise!` calls `QuotedPost.extract_from(@post)` , which delete all `quoted_posts` if there are no any quotes in a post. When two edit calls PostRevisor#revise! simultaneously, with one edit to add a quoted post and another to add a quoted post, the post content could end up with the edit that has quotes and the `quoted_post` relationship destroyed by the edit without any quotes.
## Possible Fix
Maybe we should consider acquiring a Redis lock when editing a post.
---
### Author:  [@sam](https://meta.discourse.org/u/sam)
#### Post date: [29 januari 2021 om 00:41 UTC](https://meta.discourse.org/t/possible-race-condition-when-editing-a-post/177514/2 "2021-01-29T00:41:55Z")
This is possible I guess and I am not strongly against adding a distributed lock here. The tricky thing is that I don’t want to risk any deadlocks so we would have to be extremely careful.
If concurrent editing is really your thing why not try shared edits?
> [@Discourse Shared Edits](https://meta.discourse.org/t/discourse-shared-edits/167583):
>
> discourse2Summary Discourse Shared Edits allows multiple users to collaboratively edit posts in real time. This feature is default disabled and must be enabled explicitly by moderators on posts.hammer_and_wrenchRepository Link [https://github.com/discourse/discourse-shared-edits](https://github.com/discourse/discourse-shared-edits)open_bookInstall Guide [How to install plugins in Discourse](https://meta.discourse.org/t/install-plugins-in-discourse/19157)Features Moderators (including TL4) can toggle shared edits on a topic (red) via the gear icon on the composer bar. Note that the plu…