Bartlomiej Bloniarz
d9d2502b61
Summary: Pull Request resolved: https://github.com/react/react-native/pull/57376 AnimatedPropsRegistry::update() runs on the UI thread every animation frame and created a surface's entry via operator[]. clearOnSurfaceStop() (run on the JS thread when a surface stops) erases that entry, but an in-flight animation frame landing after the stop re-created it via operator[] -- and since the surface is gone, nothing ever cleans it up again. The resurrected entry leaks its PropsSnapshot and ShadowNodeFamily for the lifetime of the registry. A surface's entry is legitimately created by getMap(), which AnimationBackendCommitHook calls on every React commit. stopSurface drains in-flight commits before unregistering the ShadowTree (ShadowTreeRegistry::remove takes the registry's unique lock, which excludes the shared-locked commit visits), so getMap() can never run for a stopped surface. That leaves update()'s operator[] as the only thing that can resurrect one. Fix: update() now only refines surfaces that already exist (find instead of operator[]) and never creates an entry; getMap() remains the sole creator. A stopped surface can no longer be resurrected, and there is no extra bookkeeping that could grow over time. Changelog: [General][Fixed] - Fix a surface-stop race in the C++ Animated shared backend that could permanently leak per-surface animated state Reviewed By: javache Differential Revision: D109156094 fbshipit-source-id: 4684ca51d372023e3b082427a225de7d84d14889
scripts/cxx-api
Python build pipeline for React Native's C++ (and Objective-C) API snapshots.
Overview
scripts/cxx-api generates human-readable snapshots of React Native's public C++ API surface. It uses Doxygen to parse C/C++/Objective-C headers and a custom Python parser to produce a simplified, sorted representation of every public symbol.
The pipeline produces one .api snapshot file per configured API view × variant combination:
| Snapshot | Description |
|---|---|
ReactCommonDebugCxx.api |
Platform-independent C++ API (debug) |
ReactCommonReleaseCxx.api |
Platform-independent C++ API (release) |
ReactAndroidDebugCxx.api |
Android-specific C++ API (debug) |
ReactAndroidReleaseCxx.api |
Android-specific C++ API (release) |
ReactAppleDebugCxx.api |
Apple-specific C++/Obj-C API (debug) |
ReactAppleReleaseCxx.api |
Apple-specific C++/Obj-C API (release) |
For each view, debug and release variants are generated with different preprocessor definitions (e.g. REACT_NATIVE_DEBUG vs NDEBUG), since #ifdef guards in the source headers can produce a different public API surface per variant.
Snapshot files are committed to the repo under scripts/cxx-api/api-snapshots/.
Usage
Generate snapshots
Maintainers should run this command whenever making intentional C++ API changes:
python -m scripts.cxx-api.parser
Validate snapshots against committed baseline
This mode generates snapshots to a temporary directory and compares them against the committed .api files. It is designed for CI:
python -m scripts.cxx-api.parser --validate
If any snapshot differs, a unified diff is printed and the process exits with a non-zero status. To fix a failing validation, regenerate the snapshots with python -m scripts.cxx-api.parser and commit the updated .api files.
How it works
The pipeline has two main stages:
1. Doxygen XML generation
Doxygen is configured via a generated config file (built from .doxygen.config.template) with the input directories, exclude patterns, and preprocessor definitions specified in config.yml. It outputs XML describing every symbol found in the headers.
2. Snapshot parsing
The Python parser (parser/) reads the Doxygen XML output and builds a scope tree of the public API surface. The tree is then serialized to a deterministically sorted, human-readable .api text format.
When to use it
The snapshot should be regenerated whenever making intentional changes to the public C++ API surface. This includes additions, removals, and changes to files located in:
xplat/js/react-native-github/xplat/js/react-native-github/ReactCommon/xplat/js/react-native-github/ReactAndroid/xplat/js/react-native-github/ReactApple/xplat/js/react-native-github/Libraries/
Configuration
All API views and their variants are defined in config.yml. Each view specifies:
| Field | Description |
|---|---|
inputs |
Directories to scan for headers |
exclude_patterns |
Glob patterns for files to skip |
definitions |
Preprocessor macros to define |
variants |
Named build variants (e.g. debug/release) with extra definitions |
codegen |
Optional codegen platform (android, ios) to generate TurboModule/Component headers before scanning |
private_directories |
Directories whose headers are scanned (they may be transitively included) but should not contribute public symbols. If any public API entity is defined in a private directory, a warning is printed to help catch accidental API exposure. |
Snapshot format
The .api files use a minimal pseudo-C++ syntax designed for easy diffing:
namespace facebook::react {
class ComponentDescriptor {
public ComponentDescriptor(ComponentDescriptorParameters params);
public ComponentHandle getComponentHandle();
}
enum class AccessibilityRole {
None = 0,
Button = 1,
}
}
- Scopes and members are sorted alphabetically.
- Access specifiers (
public,protected) are preserved. - Template parameters are included.
- Doc comments and source file names are stripped.