count is now a parameter: ./tools/benchmark-fixture.sh --count 20000 builds the folder the performance doc has been promising 5000 and 20000-file numbers for. The script validates the argument rather than quietly building the default folder, which is the failure mode that would otherwise waste a run. Verified with 1500 files and then removed.
A separate package id for the app under test is the tidier design and cannot be used on this device: a new package id needs a human to approve the install every time, and installing by tapping the APK left the package listed by pm list packages yet unknown to pm enable and invisible to PackageManager. The benchmark build type therefore keeps the app's own id and takes the release key, so it updates an installed release build and keeps its data. The trade-off is stated where it happens: this build replaces a release install, and reinstalling the release APK puts it back.
Two bugs surfaced on the way and both are now commented at the line they belong to. -PbenchmarkBuild was read with providers.gradleProperty, which reported it absent, so the runner installed the debug APK and failed on it; hasProperty is what works. And the reason am instrument cannot be used for this module is now recorded: MacrobenchmarkRule uninstalls the target at the start of a run and reinstalls it from the APK paths the Gradle runner passes in, so without those the app is uninstalled and left that way - which is what produced NameNotFoundException for an app that was installed a second earlier, twice, with Benchmark: Uninstalling in logcat to prove it.
coldStart keeps its measured number (532 ms median). The three interaction benchmarks remain unmeasured for a reason that is now written down: each run needs one tap on the phone for the reinstall MIUI gates.
Gate green, map current.
coldStart measures 532 ms median (min 499, max 805) on the benchmark build - R8, not debuggable, profileable, CompilationMode.None - against 1814 ms on the debug build, which is the honest illustration of why a debug number must never be published as the app's performance. The tool also warns that it cannot clear the runtime image on this Android version, so the figure is optimistic by an unmeasured amount; that is in PERFORMANCE.md next to the number rather than in a footnote.
The three interaction benchmarks are written and compile but have not produced a number, and getting that far took four fixes worth naming. The app under test cannot keep the app's package id (signature) and cannot use .benchmark (the test APK owns that id, INSTALL_FAILED_VERSION_DOWNGRADE); macrobenchmark needs package visibility for it or it reports NameNotFoundException for an app that pm list packages shows installed; UiAutomation.executeShellCommand runs as the test app's uid, so the fixture has to be made through adb instead - that one cost the first attempt a hang; and testBuildType has to be behind a flag or :app:testDebugUnitTest stops existing.
The workflow that works on a device with an install gate is now documented: install the two APKs by hand once, run tools/benchmark-fixture.sh, then am instrument. The Gradle task is documented as the alternative and as the reason the app under test disappeared once - it uninstalls around the run.
Gate green, map current, 386 tests unchanged.