Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52827
Changelog: [internal]
This adds **support for creating Hermes/JS sampling profiler traces in Fantom**, which is especially useful when running benchmarks.
Usage:
```
FANTOM_PROFILE_JS=1 yarn fantom Animated-benchmark
```
Output:
{F1980642216}
After this, the trace is fully symbolicated.
Can be opened directly in Google Chrome:
{F1980642229}
Or in the built-in viewer in VSCode:
{F1980642242} {F1980642240} {F1980642241}
When collapsing frames in the Flame Chart viewer in VSCode, we can quickly identify opportunities for optimizations.
This also supports multi-config environments. In that case, trace file names are created using a short representation of the configuration.
User guide for benchmarks in Fantom, including how to use this, will be done in a future diff.
NOTE: This still doesn't work in OSS because we don't support optimized mode there. In dev mode, there's a segmentation fault coming from this line: `hermesRuntime->sampledTraceToStreamInDevToolsFormat(fileStream)`
Reviewed By: sammy-SC
Differential Revision: D78905646
fbshipit-source-id: 382ddd5034db601309bd118cedde2fe0d57fde98
Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52829
Changelog: [internal]
Just a small refactor to move the definitions of output paths to a specific module. We'll add more to this in a latter diff.
Reviewed By: sammy-SC
Differential Revision: D78905645
fbshipit-source-id: 011e6cec13396301dad8e76400b6f2b9e13568f0
Rubén Norte