[Engine] FrameTiming and TimelineSummary's frame build time are not consistent #62689
Description
Tested in this branch: https://github.com/CareF/flutter/tree/compare_frametiming_and_timeline/dev/benchmarks/macrobenchmarks
in macrobenchmarks with the following command:
flutter [--local-engine-src-path ~/engine/src --local-engine=android_profile] drive \
-t test/cull_opacity_perf_e2e.dart --driver test_driver/e2e_test.dart --profile --trace-startupon a moto G4.
With this change: https://github.com/CareF/engine/commit/da7a71839c7a4ad0c39bd120f88359fb935307e5 (https://github.com/CareF/engine/tree/test_frame_timing), the difference can be reduced to:
To plot the figure, run the Python code in macrobenchmarks/build
#!/usr/bin/env python3
# -*- coding:utf-8 -*-
from pylab import *
import json
def get_build_times(filename):
with open(filename, 'r') as f:
data = json.load(f)
return data['frame_build_times']
if __name__ == '__main__':
e2e_frame_build = np.array(get_build_times('e2e_perf_summary.json')[1:])
timeline_frame_build = np.array(get_build_times('e2e_timeline.timeline_summary.json'))
plot(e2e_frame_build, label='FrameTIming.buildDuration')
plot(timeline_frame_build, label='TimelineSummary.frame_build_times')
# show()
plot(e2e_frame_build - timeline_frame_build[:len(e2e_frame_build)], label='delta')
legend()
xlabel('frame index')
ylabel('time in microseconds')
ylim(-1E4, 80000)
show()