Valentin Shergin
913c958751
Summary: We need to register a root view component here synchronously because right after we start a surface, it can initiate an update that can query the root component. This fixes an issue in Fabric Surface caused by a data race between registration of root component and concurrent call to `constraintLayout` on the main thread. This how it happens: 1. We call `startSurface` on some background thread; 2. As a result `[RCTFabricSurface start]` schedules a lambda to the main thread that will register a root component. 3. Meanwhile some other code on the main thread changes the layout and requests the relayout of a surface. 4. Because the surface is already running, the `constraintLayout` method works as expected and schedules a mutation instruction that changes the size of the root component. 5. The mutation instruction is being delivered synchronously on the main thread and fails because the root component was not yet registered. Boom. For now, it's not fully clear how to solve this problem properly. I suspect that the good solution would be to shift the responsibility of registering a root component to the MountingCoordinator side (so, we will have an explicit instruction prescribing creating and registering the root component). This will probably be a quite invasive change though. For now, I think it's fine to make the block synchronous to avoid the race. Reviewed By: mdvacca Differential Revision: D26802418 fbshipit-source-id: d49484c90d1ac61ac595caf486562fc6f4843e2f
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 11.0 and Android 5.0 (API 21) 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.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our Contributing Guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React Native.
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.
React Native documentation is Creative Commons licensed, as found in the LICENSE-docs file.