Update README for ActivityManagerPerfTests

ActivityManagerPerfTests

Performance tests for various ActivityManager components, e.g. Services, Broadcasts

* These are only for tests that don't require a target package to test against

* Self-contained perf tests should go in frameworks/base/apct-tests/perftests

Command to run tests (not working yet, atest seems buggy)

* atest .../frameworks/base/tests/ActivityManagerPerfTests

Command to run tests

* atest .../frameworks/base/tests/ActivityManagerPerfTests/tests/

  * Command currently not working: b/71859981

* m ActivityManagerPerfTests ActivityManagerPerfTestsTestApp && \

  adb install $OUT/data/app/ActivityManagerPerfTests/ActivityManagerPerfTests.apk && \

  adb install $OUT/data/app/ActivityManagerPerfTestsTestApp/ActivityManagerPerfTestsTestApp.apk && \

  adb install "$OUT"/data/app/ActivityManagerPerfTests/ActivityManagerPerfTests.apk && \

  adb install "$OUT"/data/app/ActivityManagerPerfTestsTestApp/ActivityManagerPerfTestsTestApp.apk && \

  adb shell am instrument -w \

  com.android.frameworks.perftests.amtests/android.support.test.runner.AndroidJUnitRunner

  * For example, the time it takes from sending an Intent to start a Service

    to the time the Service runs its callbacks

* System.nanoTime() is monotonic and consistent between processes, so we use that for measuring time

* To make sure the test app is running, we start an Activity

* If the test app is involved, it will measure the time and send it back to the instrumentation test

  * The time is sent back through a Binder interface in the Intent

  * The time is sent back through a Binder interface in the Intent with the help of Utils.sendTime()

  * Each sent time is tagged with an id since there can be multiple events that send back a time

    * For example, one is sent when the Activity is started, and another could be sent when a

      Broadcast is received

* Each test will run multiple times to account for variation in test runs

Structure

* tests

  * Instrumentation test which runs the various performance tests and reports the results

* test-app

  * Target package which contains the Services, BroadcastReceivers, etc. to test against

  * Sends the time it measures back to the test package

* utils

  * Utilities that both the instrumentation test and test app can use

Adding tests

* Example

  * Look at tests/src/com/android/frameworks/perftests/am/BroadcastPerfTest and

    test-app/src/com/android/frameworks/perftests/amteststestapp/TestBroadcastReceiver

    for simple examples using this framework

* Steps

  * Add any components you will test against in the target package under

    test-app/src/com/android/frameworks/perftests/amteststestapp/

  * Add the test class under tests/src/com/android/frameworks/perftests/am/tests/

    * The class should extend BasePerfTest

    * Each test should call runPerfFunction() returning the elapsed time for a single iteration

    * The test has access to a Context through mContext

  * If you are measuring the time elapsed of something that either starts or ends in the target

    package

    * The target package can report the time it measures through an ITimeReceiverCallback passed

      through an Intent through Utils.sendTime(intent, "tag")

      (or however a Binder needs to be passed to the target package)

    * The instrumentation test can collect that time by calling getReceivedTimeNs("tag") and

      calculate the elapsed time

    * Each timestamp sent to the instrumentation test is tagged with a tag since multiple timestamps

      can be reported in an iteration

  * If the target package should be running before your test logic starts, add startTargetPackage();

    at the beginning of the iteration

* Reporting

  * Look at go/am-perf for how to add new tests to dashboards and receive notification on regression