switching src quickly will crash on iOS

[wood1986]

Bug

switching src quickly will crash on iOS especially when you app is huge

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Cannot remove an observer <NSKeyValueObservance 0x600000a150b0> for the key path "currentItem.liveUpdateInterval" from <AVPlayer 0x600001ba8880>, most likely because the value for the key "currentItem" has changed without an appropriate KVO notification being sent. Check the KVO-compliance of the AVPlayer class.'

Platform

Which player are you experiencing the problem on:

• iOS

Environment info

React native info output:

System:
    OS: macOS 12.6
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 1.14 GB / 32.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 18.9.0 - /private/var/folders/xn/9sz2plkj3wbf2lj_ths6_ykr0000gn/T/xfs-2f68018f/node
    Yarn: 3.2.4 - /private/var/folders/xn/9sz2plkj3wbf2lj_ths6_ykr0000gn/T/xfs-2f68018f/yarn
    npm: 8.19.1 - ~/.nvm/versions/node/v18.9.0/bin/npm
    Watchman: 2022.10.10.00 - /usr/local/bin/watchman
  Managers:
    CocoaPods: 1.11.3 - /Users/wood/.rbenv/shims/pod
  SDKs:
    iOS SDK:
      Platforms: DriverKit 21.4, iOS 16.0, macOS 12.3, tvOS 16.0, watchOS 9.0
    Android SDK: Not Found
  IDEs:
    Android Studio: 2021.3 AI-213.7172.25.2113.9014738
    Xcode: 14.0.1/14A400 - /usr/bin/xcodebuild
  Languages:
    Java: 11.0.16.1 - /usr/bin/javac
  npmPackages:
    @react-native-community/cli: Not Found
    react: 18.0.0 => 18.0.0
    react-native: 0.69.3 => 0.69.3
    react-native-macos: Not Found
  npmGlobalPackages:
    *react-native*: Not Found

Library version: 6.0.0-alpha.3

Steps To Reproduce

1. git clone https://github.com/wood1986/react-native-fullscreen-example.git
2. git checkout bug/crash-kvo-compliance
3. yarn && cd ios && pod install && yarn ios
4. Click 'Next' button quickly
   ...

Expected behaviour

1. It should not crash

Reproducible sample code

https://github.com/wood1986/react-native-fullscreen-example/tree/bug/crash-kvo-compliance

Video sample

If possible, include a link to the video that has the problem that can be streamed or downloaded from.

[wood1986]

This PR #2848 causes the issue. If I undo this PR, it works fine

[freeboub]

@wood1986 It was fixing a latency (all UI blocks) while starting a stream, I was afraid of such issue due to thread safety (and it is the case)...
2 solutions: either we revert the change or you can try to put the whole start function inside DispatchQueue.
Please let me know !

[wood1986]

put the whole start function inside DispatchQueue.

like my PR?

[wood1986]

@matinzd could you verify this fix on iOS?