From d48954fb6bd5fb3170ea44b95c87ed2b7a70d535 Mon Sep 17 00:00:00 2001
From: Dianne Hackborn <hackbod@google.com>
Date: Wed, 22 Jul 2015 17:20:33 -0700
Subject: [PATCH] Fix issue #22414729: Checkin start clock time is different
 from hsitory reset time

There was a mistake in the code that was supposed to recover from the
initial time on a new device being bad until the real time ultimately
gets set, which was causing us to update the start clock time every time
there was a time change (instead of just when the original start time
appears bad).

Rework all of this, so we now count the start time as bad if it is more
than one year before the current time, only modifying it in that case.
Also when modifying it, adjust the time we set it to take in to account
how much realtime has actually elapsed so far in the battery stats.

Change-Id: If74bd711d9b7618c8f6148a9935c452aaaa7e257
---
 .../android/internal/os/BatteryStatsImpl.java | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/core/java/com/android/internal/os/BatteryStatsImpl.java b/core/java/com/android/internal/os/BatteryStatsImpl.java
index 60f47d673c180..e7c58f45c18c7 100644
--- a/core/java/com/android/internal/os/BatteryStatsImpl.java
+++ b/core/java/com/android/internal/os/BatteryStatsImpl.java
@@ -2560,14 +2560,24 @@ public final class BatteryStatsImpl extends BatteryStats {
         addHistoryEventLocked(elapsedRealtime, uptime, code, name, uid);
     }
 
+    boolean ensureStartClockTime(final long currentTime) {
+        final long ABOUT_ONE_YEAR = 365*24*60*60*1000L;
+        if (currentTime > ABOUT_ONE_YEAR && mStartClockTime < (currentTime-ABOUT_ONE_YEAR)) {
+            // If the start clock time has changed by more than a year, then presumably
+            // the previous time was completely bogus.  So we are going to figure out a
+            // new time based on how much time has elapsed since we started counting.
+            mStartClockTime = currentTime - (SystemClock.elapsedRealtime()-(mRealtimeStart/1000));
+            return true;
+        }
+        return false;
+    }
+
     public void noteCurrentTimeChangedLocked() {
         final long currentTime = System.currentTimeMillis();
         final long elapsedRealtime = SystemClock.elapsedRealtime();
         final long uptime = SystemClock.uptimeMillis();
         recordCurrentTimeChangeLocked(currentTime, elapsedRealtime, uptime);
-        if (isStartClockTimeValid()) {
-            mStartClockTime = currentTime;
-        }
+        ensureStartClockTime(currentTime);
     }
 
     public void noteProcessStartLocked(String name, int uid) {
@@ -4306,19 +4316,11 @@ public final class BatteryStatsImpl extends BatteryStats {
         }
     }
 
-    boolean isStartClockTimeValid() {
-        return mStartClockTime > 365*24*60*60*1000L;
-    }
-
     @Override public long getStartClockTime() {
-        if (!isStartClockTimeValid()) {
-            // If the last clock time we got was very small, then we hadn't had a real
-            // time yet, so try to get it again.
-            mStartClockTime = System.currentTimeMillis();
-            if (isStartClockTimeValid()) {
-                recordCurrentTimeChangeLocked(mStartClockTime, SystemClock.elapsedRealtime(),
-                        SystemClock.uptimeMillis());
-            }
+        final long currentTime = System.currentTimeMillis();
+        if (ensureStartClockTime(currentTime)) {
+            recordCurrentTimeChangeLocked(currentTime, SystemClock.elapsedRealtime(),
+                    SystemClock.uptimeMillis());
         }
         return mStartClockTime;
     }