AppIdleHistory: Only write screen on durations during regular sync

am: f2d87eba75

Change-Id: I7e5a6d89afa813fdb68c68d201ad04971641dabd

services/tests/servicestests/src/com/android/server/usage/AppIdleHistoryTests.java

@@ -67,7 +67,7 @@ public class AppIdleHistoryTests extends AndroidTestCase {
         // Screen on time should not keep progressing with screen is off
         assertEquals(aih.getScreenOnTimeLocked(7000), 3000);
         assertEquals(aih.getScreenOnTimeLocked(8000), 3000);
-        aih.writeElapsedTimeLocked();
+        aih.writeAppIdleDurationsLocked();
 
         // Check if the screen on time is persisted across instantiations
         AppIdleHistory aih2 = new AppIdleHistory(mStorageDir, 0);

services/usage/java/com/android/server/usage/AppIdleHistory.java

@@ -118,7 +118,6 @@ public class AppIdleHistory {
         } else {
             mScreenOnDuration += elapsedRealtime - mScreenOnSnapshot;
             mElapsedDuration += elapsedRealtime - mElapsedSnapshot;
-            writeScreenOnTimeLocked();
             mElapsedSnapshot = elapsedRealtime;
         }
     }
@@ -167,7 +166,7 @@ public class AppIdleHistory {
     /**
      * To be called periodically to keep track of elapsed time when app idle times are written
      */
-    public void writeElapsedTimeLocked() {
+    public void writeAppIdleDurationsLocked() {
         final long elapsedRealtime = SystemClock.elapsedRealtime();
         // Only bump up and snapshot the elapsed time. Don't change screen on duration.
         mElapsedDuration += elapsedRealtime - mElapsedSnapshot;

services/usage/java/com/android/server/usage/UsageStatsService.java

@@ -304,9 +304,9 @@ public class UsageStatsService extends SystemService implements
 
         @Override public void onDisplayChanged(int displayId) {
             if (displayId == Display.DEFAULT_DISPLAY) {
+                final boolean displayOn = isDisplayOn();
                 synchronized (UsageStatsService.this.mLock) {
-                    mAppIdleHistory.updateDisplayLocked(isDisplayOn(),
-                            SystemClock.elapsedRealtime());
+                    mAppIdleHistory.updateDisplayLocked(displayOn, SystemClock.elapsedRealtime());
                 }
             }
         }
@@ -1005,9 +1005,9 @@ public class UsageStatsService extends SystemService implements
             service.persistActiveStats();
             mAppIdleHistory.writeAppIdleTimesLocked(mUserState.keyAt(i));
         }
-        // Persist elapsed time periodically, in case screen doesn't get toggled
-        // until the next boot
-        mAppIdleHistory.writeElapsedTimeLocked();
+        // Persist elapsed and screen on time. If this fails for whatever reason, the apps will be
+        // considered not-idle, which is the safest outcome in such an event.
+        mAppIdleHistory.writeAppIdleDurationsLocked();
         mHandler.removeMessages(MSG_FLUSH_TO_DISK);
     }