Summary:
Note: PR to react-native-macos here https://github.com/microsoft/react-native-macos/pull/733
Internally in Microsoft code, we ran into a deadlock where the main queue and the UIManager queue were both trying to access `[RCTI18nUtil sharedInstance]`, and were blocked on each other. This is similar to an earlier issue with RCTScreenScale decsribed [here](https://github.com/facebook/react-native/issues/18096).
To summarize:
1- RCTShadowView (on the UIManager queue) and RCTView (on the main queue) both try to access `[RCTI18nUtil sharedInstance]`
2- The UIManager thread gets there first, and lazily initializes the sharedInstance. Meanwhile, the main thread is waiting on a lock possessed by the UIManager thread
3- As part of the initialization, we set an NSUserDefault, which seems to require the (blocked) main thread.
4- Deadlock.
For whatever reason, this only happens on debug. I did not figure out why, but I do know based on [this comment](https://github.com/facebook/react-native/issues/18096#issuecomment-368718081), that the UIManagerQueue should never block the main queue.
The fix is to not use NSUserDefaults, and simpy use atomic properties instead. We get the thread safety for free, and it also simplifies the code somewhat without changing the public API. The downside is values aren't persisted anymore, but I do not think that was necessary / intended.
## Changelog
<!-- Help reviewers and the release process by writing your own changelog entry. For an example, see:
https://github.com/facebook/react-native/wiki/Changelog
-->
[iOS] [Fixed] - Fix deadlock on RCTi18nUtil
Pull Request resolved: https://github.com/facebook/react-native/pull/31032
Test Plan:
Ran the RTLExample in RNTester, and ensured switching to RTL still worked, and that setting forceRTL would still work after reloading the bundle.
https://user-images.githubusercontent.com/6722175/108775429-aefdae80-7526-11eb-9a89-3114f7ddc2af.mov
Reviewed By: javache
Differential Revision: D29522152
Pulled By: RSNara
fbshipit-source-id: 160840f63a7b1d6721b0fd8294fb11990a4509fa
Summary: This change drops the year from the copyright headers and the LICENSE file.
Reviewed By: yungsters
Differential Revision: D9727774
fbshipit-source-id: df4fc1e4390733fe774b1a160dd41b4a3d83302a
Summary:
Includes React Native and its dependencies Fresco, Metro, and Yoga. Excludes samples/examples/docs.
find: ^(?:( *)|( *(?:[\*~#]|::))( )? *)?Copyright (?:\(c\) )?(\d{4})\b.+Facebook[\s\S]+?BSD[\s\S]+?(?:this source tree|the same directory)\.$
replace: $1$2$3Copyright (c) $4-present, Facebook, Inc.\n$2\n$1$2$3This source code is licensed under the MIT license found in the\n$1$2$3LICENSE file in the root directory of this source tree.
Reviewed By: TheSavior, yungsters
Differential Revision: D7007050
fbshipit-source-id: 37dd6bf0ffec0923bfc99c260bb330683f35553e
Summary:
1. Provide forceRTL function for developer to test RTL layout in LTR language bundle in I18nUtil and expose it in I18nManager.
2. Rename `allowRTL` and `setAllowRTL` functions
Reviewed By: fkgozali
Differential Revision: D3663693
fbshipit-source-id: 3db13a44c069ae73d1728c211306422db5dd8122
Summary: Rename the forceRTL to allowRTL so that make it much clear to read. And change a typo.
Reviewed By: fkgozali
Differential Revision: D3489235
fbshipit-source-id: b9803dfbcda2f764b7e752c9810cfc7a0b9fe39b
Summary: Create a module for React Native to get IsRTL information and set ForceRTL function.
Reviewed By: fkgozali
Differential Revision: D3446871
fbshipit-source-id: 736edf138a89d222818071370ac49dc54bda63b7
Saad Najmi
Andres Suarez
Héctor Ramos
Sophie Alpert
Ramanpreet Nara
Frank Manns
Mengjue Wang
