Ramanpreet Nara
2c473e1a38
Summary: ## Problems: In my investigation of T65656635, I realized that the TurboModule system has a number of problems: - In TurboModules, we use 1 lock to create n TurboModules. We should change this setup to n locks for n TurboModules. This way, two threads creating two different NativeModules don't compete for the same lock. Also, this is how it's done in Android (TurboModules & NativeModules), and iOS (NativeModules). - In TurboModules, we don't calculate "requires main queue setup" faithfully. In the legacy system, if a NativeModule has a custom `init` method or a custom `constantsToExport` method, it "requires main queue setup" with a warning. - In TurboModules, we don't create the NativeModule on the main queue, if "requires main queue setup" is true. Instead, the NativeModule is always created on the thread that requires it. - In TurboModules, we don't perform any concurrency control around `id<RCTTurboModule>` setup. We should. ## What this diff does In this diff, I fixed all the aforementioned issues by re-implementing `provideRCTTurboModule:`. **Algorithm Notes:** - **Gist:** When `n` threads race to create NativeModule `x`, only the first thread creates and sets up `x`. All others are told to wait. Once the creator thread finishes its job, it notifies all other waiting threads, which then wake up and return the newly created NativeModule. This algorithm was initially implemented in NativeModules for Android inside (ModuleHolder.java). I modified and implemented it for TurboModules for Android, and now this diff implements it for TurboModules for iOS. - The TurboModule cache is replace with a TurboModuleHolder map. A TurboModuleHolder manages the creation lifecycle of a TurboModule, and holds a condition variable and mutex for doing concurrency control around it. When the bridge invalidates, in TurboModuleManager, we set the `invalidating` flag to true, which prevents the insertion of new entries into the TurboModuleHolder map. - I added a `std::mutex` to serialize calls into the TurboModuleManagerDelegate, so we don't get races if the delegate isn't thread-safe. Changelog: [iOS][Fixed] - Re-implement RCTTurboModuleManager provideRCTTurboModule: Reviewed By: shergin Differential Revision: D21170099 fbshipit-source-id: 8792812c2237d3bfc80c9834c818e011de85b0ea
React Native
Learn once, write anywhere:
Build mobile apps with React.
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React Native brings React's declarative UI framework to iOS and Android. With React Native, you use native UI controls and have full access to the native platform.
- Declarative. React makes it painless to create interactive UIs. Declarative views make your code more predictable and easier to debug.
- Component-Based. Build encapsulated components that manage their state, then compose them to make complex UIs.
- Developer Velocity. See local changes in seconds. Changes to JavaScript code can be live reloaded without rebuilding the native app.
- Portability. Reuse code across iOS, Android, and other platforms.
React Native is developed and supported by many companies and individual core contributors. Find out more in our ecosystem overview.
Contents
- Requirements
- Building your first React Native app
- Documentation
- Upgrading
- How to Contribute
- Code of Conduct
- License
📋 Requirements
React Native apps may target iOS 10.0 and Android 4.1 (API 16) or newer. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS. Tools like Expo can be used to work around this.
🎉 Building your first React Native app
Follow the Getting Started guide. The recommended way to install React Native depends on your project. Here you can find short guides for the most common scenarios:
📖 Documentation
The full documentation for React Native can be found on our website.
The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
The source for the React Native documentation and website is hosted on a separate repo, @facebook/react-native-website.
🚀 Upgrading
Upgrading to new versions of React Native may give you access to more APIs, views, developer tools, and other goodies. See the Upgrading Guide for instructions.
React Native releases are discussed in the React Native Community, @react-native-community/react-native-releases.
👏 How to Contribute
The main purpose of this repository is to continue evolving React Native core. We want to make contributing to this project as easy and transparent as possible, and we are grateful to the community for contributing bug fixes and improvements. Read below to learn how you can take part in improving React Native.
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Contributing Guide
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Open Source Roadmap
You can learn more about our vision for React Native in the Roadmap.
Good First Issues
We have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started, gain experience, and get familiar with our contribution process.
Discussions
Larger discussions and proposals are discussed in @react-native-community/discussions-and-proposals.
📄 License
React Native is MIT licensed, as found in the LICENSE file.
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