Google Git
Sign in
android/platform/frameworks/base.git/android17-release/./tests/BouncyBall
tree: 1a58be6b7e5f1c7a2517526ee9659e1a2d0099ed
  1. app/
  2. Android.bp
  3. automation_config.pbtx
  4. OWNERS
  5. README.md
  6. trace_metrics_v2_spec.pbtx
tests/BouncyBall/README.md

BouncyBall Test App

BouncyBall is a simple graphics app that draws a bouncing ball, used for automated testing to detect dropped frames.

It ensures basic graphics rendering remains smooth even as system resources fluctuate. For more details on performance evaluation, see Evaluating performance.

Building and Running

To build, install, and run the app locally:

# Build
$ mmma -j frameworks/base/tests/BouncyBall

# Install
$ adb install ${ANDROID_PRODUCT_OUT}/system/app/BouncyBallTest/BouncyBallTest.apk

# Start
$ adb shell am start -W com.android.test.bouncyball/com.android.test.bouncyball.BouncyBallActivity

# Stop
$ adb shell am force-stop com.android.test.bouncyball

# Uninstall
$ adb uninstall com.android.test.bouncyball

Note: The app assumes it is the only foreground app during testing. If not, it will log an “ASSUMPTION FAILURE” error. On a properly configured device, no frames should be dropped.

Debugging

You can change boolean constants in app/src/main/java/com/android/test/bouncyball/BouncyBallActivity.java to aid debugging. Recompile the app after any changes.

  • FORCE_DROPPED_FRAMES: Intentionally drop every 64th frame to test detection.
  • ASSUMPTION_FAILURE_FORCES_EXIT: Set to false to prevent the app from exiting when it's not in the foreground.

For detailed performance analysis and debugging frame drops, use on-device tracing. See On-device tracing for guidance.

GPU Composition

BouncyBall's simplicity may cause some devices to bypass GPU composition. You can force it on for testing:

# Force GPU composition on
$ adb shell sfdo force-client-composition enabled

# Return to default GPU composition
$ adb shell sfdo force-client-composition disabled

Automation Analysis

Automated testing uses Perfetto to trace frame drops. This analysis confirms whether frames were dropped but is not intended for debugging why they were dropped.

Running the Trace

# Ensure app is installed but stopped
$ adb shell am force-stop com.android.test.bouncyball

# Set up and run Perfetto trace
$ adb push automation_config.pbtx /data/misc/perfetto-configs/
$ adb shell /system/bin/perfetto --background --config /data/misc/perfetto-configs/automation_config.pbtx --txt --out /data/misc/perfetto-traces/bouncy_trace
# Note the PERFETTO_PID from the output

# Launch the app
$ adb shell am start -W com.android.test.bouncyball/com.android.test.bouncyball.BouncyBallActivity

# Wait for Perfetto to finish (approx. 2 minutes)
$ adb shell 'while ps -p PERFETTO_PID >/dev/null; do sleep 1; done'

# Pull trace and analyze
$ adb pull /data/misc/perfetto-traces/bouncy_trace .
$ ../../../../prebuilts/tools/linux-x86_64/perfetto/trace_processor_shell \
  --summary --summary-metrics-v2 all \
  --summary-spec trace_metrics_v2_spec.pbtx bouncy_trace

A successful run will show bouncyball_failing_jank_instance_count, the last “value” in the output, as 0.

Cleanup

# Clean up device
$ adb shell rm /data/misc/perfetto-configs/automation_config.pbtx /data/misc/perfetto-traces/bouncy_trace

# Clean up local directory
$ rm bouncy_trace