realm-js: Realm + Reanimated v2 w/ JSC causes Realm to not work

Same problem, we have to use reanimated v2 to for other dependencies, and it’s urgent for us to find a solution to use both together. Looking forward to hear more

Hi @kneth, any news on this one yet?

We’re starting on the implementation of something which would be a lot simpler in reanimated v2 due to the new API but we’re having to stick to v1 for now due to this conflict with Realm.

FYI, I’ve retested with the latest versions of both projects (Realm 10.6.1 and Reanimated 2.2.0) but, unsurprisingly, it still happens. Interestingly the behaviour seems somewhat variable? Possibly a race between the two modules hooking into the JSC?

If I use the minimal repro off of the reanimated ticket (https://github.com/limpbrains/reanimated-2-playground) it doesn’t always crash when I hit the ‘write to realm’ button. Sometimes it crashes the app (seems more likely if I tap the button as soon as it’s available, rather than waiting) but when it does ‘work’ I’ve seen varying output from the console.log statement:

[Tue Aug 10 2021 18:08:34.961]  LOG      created two tasks:  &
...
[Tue Aug 10 2021 18:09:01.886]  LOG      created two tasks: Wrapper & Wrapper
...
[Tue Aug 10 2021 18:09:26.881]  LOG      created two tasks: undefined & undefined

Also, if there’s anything extra we can provide to help (tombstones, etc) let us know.

Our Hermes release branch currently solves all issues related to Reanimated v2. Please use this branch if your project needs react-native-reanimated. If you are having any issues with the current Hermes release branch, please open a new ticket describing your issue.

To quickly switch to this release branch, use the following command:

npm install realm@hermes

We are actively working on this branch, so any input would be appreciated 😃

I don’t think there’s any other workarounds that I am aware of, although perhaps someone from the community has some ideas. We’re hoping we can solve the performance regressions soon. Sorry, I realise it’s not ideal, but since realising the impact we are treating this as a high priority.

@liamjones Yes, you do not need to enable Hermes for this to work.
A part of the hermes effort was fixing the bridge between Android and the javascript engine. This fixes the conflict we were having with the way react-native-reanimated establishes this bridge.

No worries, I know you’re working hard on this. I want the JSI implementation to work because when it does it will be 🔥

Sounds like you’re close!

thanks @liamjones

@AzadMohammadi-z Please take a look at https://github.com/realm/realm-js/blob/v11/COMPATIBILITY.md to find a compatible version. Best is to upgrade to latest version but it will also include upgrading React Native.

I think I’m having the same problem my app keeps crashing when i use realm in drawer or tab navigation but works fine on stack. plzz tell me how to sort this issue. I’m using react native reanimated v2

I’m using realm@hermes as @takameyer suggested and it is working, there are still some random crashes but it is better than without it.

@hungnv2010 then please attach some reproducible example, because the original issue was about data loss or crash on reload. Looks like you have something different here

Anyone who is eager to have this issue fixed, please try the latest betas of 10.20 with hermes support. In my experiments, it was working out of the box

Same having this problem with realm + reanimated v2 which is a major problem as reanimated v2 looks like a requirement for some camera packages i need

https://github.com/software-mansion/react-native-reanimated/issues/1424

Oh! Yes, v1 works here too. It’s only an issue with v2 (which we’re trying to upgrade to for the new API).

Thank you for cross-posting. We will have to investigate it further to understand the interaction between JavaScriptCore and the two libraries is.