From e4207adfe317823438340c2a6a261a5bb8bd39c7 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Tue, 18 Jul 2023 14:45:28 +0000
Subject: [PATCH] Update to cold launch if the process is restarted during
 launching

The current common case is that the process of the resuming activity
is just unfrozen but its binder buffer is full (someone still sends
async binder call to it when it is frozen) and the process could
be killed because binder transaction failed. Then the process will
attach again so the launch type can be corrected to COLD to avoid
disturb the distribution of metrics.

Bug: 291599121
Test: atest ActivityMetricsLaunchObserverTests#testLaunchState
Change-Id: I26252410508d21aacacd35bd6cc305dc7a0fc9f9
---
 .../server/wm/ActivityMetricsLogger.java      | 17 ++++++++++++++--
 .../ActivityMetricsLaunchObserverTests.java   | 20 ++++++++++++-------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
index c5f63ced989cf..a6d5c19395b01 100644
--- a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
+++ b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
@@ -285,9 +285,9 @@ class ActivityMetricsLogger {
         final LaunchingState mLaunchingState;
 
         /** The type can be cold (new process), warm (new activity), or hot (bring to front). */
-        final int mTransitionType;
+        int mTransitionType;
         /** Whether the process was already running when the transition started. */
-        final boolean mProcessRunning;
+        boolean mProcessRunning;
         /** whether the process of the launching activity didn't have any active activity. */
         final boolean mProcessSwitch;
         /** The process state of the launching activity prior to the launch */
@@ -972,6 +972,19 @@ class ActivityMetricsLogger {
             // App isn't attached to record yet, so match with info.
             if (info.mLastLaunchedActivity.info.applicationInfo == appInfo) {
                 info.mBindApplicationDelayMs = info.calculateCurrentDelay();
+                if (info.mProcessRunning) {
+                    // It was HOT/WARM launch, but the process was died somehow right after the
+                    // launch request.
+                    info.mProcessRunning = false;
+                    info.mTransitionType = TYPE_TRANSITION_COLD_LAUNCH;
+                    final String msg = "Process " + info.mLastLaunchedActivity.info.processName
+                            + " restarted";
+                    Slog.i(TAG, msg);
+                    if (info.mLaunchingState.mTraceName != null) {
+                        Trace.instant(Trace.TRACE_TAG_ACTIVITY_MANAGER, msg + "#"
+                                + LaunchingState.sTraceSeqId);
+                    }
+                }
             }
         }
     }
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
index 5c3102d870d01..65e77dcd4ca91 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
@@ -182,12 +182,12 @@ public class ActivityMetricsLaunchObserverTests extends WindowTestsBase {
 
     @Test
     public void testLaunchState() {
-        final ToIntFunction<Boolean> launchTemplate = doRelaunch -> {
+        final ToIntFunction<Runnable> launchTemplate = action -> {
             clearInvocations(mLaunchObserver);
             onActivityLaunched(mTopActivity);
             notifyTransitionStarting(mTopActivity);
-            if (doRelaunch) {
-                mActivityMetricsLogger.notifyActivityRelaunched(mTopActivity);
+            if (action != null) {
+                action.run();
             }
             final ActivityMetricsLogger.TransitionInfoSnapshot info =
                     notifyWindowsDrawn(mTopActivity);
@@ -199,21 +199,27 @@ public class ActivityMetricsLaunchObserverTests extends WindowTestsBase {
         // Assume that the process is started (ActivityBuilder has mocked the returned value of
         // ATMS#getProcessController) but the activity has not attached process.
         mTopActivity.app = null;
-        assertWithMessage("Warm launch").that(launchTemplate.applyAsInt(false /* doRelaunch */))
+        assertWithMessage("Warm launch").that(launchTemplate.applyAsInt(null))
                 .isEqualTo(WaitResult.LAUNCH_STATE_WARM);
 
         mTopActivity.app = app;
         mNewActivityCreated = false;
-        assertWithMessage("Hot launch").that(launchTemplate.applyAsInt(false /* doRelaunch */))
+        assertWithMessage("Hot launch").that(launchTemplate.applyAsInt(null))
                 .isEqualTo(WaitResult.LAUNCH_STATE_HOT);
 
-        assertWithMessage("Relaunch").that(launchTemplate.applyAsInt(true /* doRelaunch */))
+        assertWithMessage("Relaunch").that(launchTemplate.applyAsInt(
+                () -> mActivityMetricsLogger.notifyActivityRelaunched(mTopActivity)))
                 .isEqualTo(WaitResult.LAUNCH_STATE_RELAUNCH);
 
+        assertWithMessage("Cold launch by restart").that(launchTemplate.applyAsInt(
+                () -> mActivityMetricsLogger.notifyBindApplication(
+                        mTopActivity.info.applicationInfo)))
+                .isEqualTo(WaitResult.LAUNCH_STATE_COLD);
+
         mTopActivity.app = null;
         mNewActivityCreated = true;
         doReturn(null).when(mAtm).getProcessController(app.mName, app.mUid);
-        assertWithMessage("Cold launch").that(launchTemplate.applyAsInt(false /* doRelaunch */))
+        assertWithMessage("Cold launch").that(launchTemplate.applyAsInt(null))
                 .isEqualTo(WaitResult.LAUNCH_STATE_COLD);
     }