Better handling of NTP-based clocks.

Now that we have a nice Clock abstraction, we can use it to represent
a clock backed by an NTP fix.  (This makes testing logic much easier
to write.)

We now rely completely on NetworkTimeUpdateService to keep our NTP
fix up to date, instead of trying to refresh in the middle of
critical paths which could trigger random ANRs.

Add internal FallbackClock to make it easier to handle missing NTP
fixes.  Add internal SimpleClock to let implementers focus on single
millis() method.

Test: bit FrameworksNetTests:com.android.server.net.NetworkStatsServiceTest
Test: bit FrameworksServicesTests:com.android.server.NetworkPolicyManagerServiceTest
Bug: 69714690, 72320957
Change-Id: Ic32cdcbe093d08b73b0e4b23d6910b23ea8e1968
Exempt-From-Owner-Approval: approved in previous PS
diff --git a/api/current.txt b/api/current.txt
index 9bc3150..022c8ba 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -33036,14 +33036,14 @@
   }
 
   public final class SystemClock {
+    method public static java.time.Clock currentNetworkTimeClock();
+    method public static long currentNetworkTimeMillis();
     method public static long currentThreadTimeMillis();
     method public static long elapsedRealtime();
-    method public static java.time.Clock elapsedRealtimeClock();
     method public static long elapsedRealtimeNanos();
     method public static boolean setCurrentTimeMillis(long);
     method public static void sleep(long);
     method public static long uptimeMillis();
-    method public static java.time.Clock uptimeMillisClock();
   }
 
   public class TestLooperManager {
diff --git a/api/removed.txt b/api/removed.txt
index 2aab223..55022f3 100644
--- a/api/removed.txt
+++ b/api/removed.txt
@@ -257,6 +257,12 @@
     ctor public RecoverySystem();
   }
 
+  public final class SystemClock {
+    method public static java.time.Clock elapsedRealtimeClock();
+    method public static java.time.Clock uptimeClock();
+    method public static deprecated java.time.Clock uptimeMillisClock();
+  }
+
   public class TestLooperManager {
     method public deprecated android.os.MessageQueue getQueue();
   }
diff --git a/core/java/android/app/IAlarmManager.aidl b/core/java/android/app/IAlarmManager.aidl
index 7b05b49..ded4c49 100644
--- a/core/java/android/app/IAlarmManager.aidl
+++ b/core/java/android/app/IAlarmManager.aidl
@@ -37,4 +37,5 @@
     void remove(in PendingIntent operation, in IAlarmListener listener);
     long getNextWakeFromIdleTime();
     AlarmManager.AlarmClockInfo getNextAlarmClock(int userId);
+    long currentNetworkTimeMillis();
 }
diff --git a/core/java/android/os/BestClock.java b/core/java/android/os/BestClock.java
new file mode 100644
index 0000000..aa066b6
--- /dev/null
+++ b/core/java/android/os/BestClock.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.os;
+
+import android.util.Log;
+
+import java.time.Clock;
+import java.time.DateTimeException;
+import java.time.ZoneId;
+import java.util.Arrays;
+
+/**
+ * Single {@link Clock} that will return the best available time from a set of
+ * prioritized {@link Clock} instances.
+ * <p>
+ * For example, when {@link SystemClock#currentNetworkTimeClock()} isn't able to
+ * provide the time, this class could use {@link Clock#systemUTC()} instead.
+ *
+ * @hide
+ */
+public class BestClock extends SimpleClock {
+    private static final String TAG = "BestClock";
+
+    private final Clock[] clocks;
+
+    public BestClock(ZoneId zone, Clock... clocks) {
+        super(zone);
+        this.clocks = clocks;
+    }
+
+    @Override
+    public long millis() {
+        for (Clock clock : clocks) {
+            try {
+                return clock.millis();
+            } catch (DateTimeException e) {
+                // Ignore and attempt the next clock
+                Log.w(TAG, e.toString());
+            }
+        }
+        throw new DateTimeException(
+                "No clocks in " + Arrays.toString(clocks) + " were able to provide time");
+    }
+}
diff --git a/core/java/android/os/SimpleClock.java b/core/java/android/os/SimpleClock.java
new file mode 100644
index 0000000..efc271f54
--- /dev/null
+++ b/core/java/android/os/SimpleClock.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.os;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneId;
+
+/** {@hide} */
+public abstract class SimpleClock extends Clock {
+    private final ZoneId zone;
+
+    public SimpleClock(ZoneId zone) {
+        this.zone = zone;
+    }
+
+    @Override
+    public ZoneId getZone() {
+        return zone;
+    }
+
+    @Override
+    public Clock withZone(ZoneId zone) {
+        return new SimpleClock(zone) {
+            @Override
+            public long millis() {
+                return SimpleClock.this.millis();
+            }
+        };
+    }
+
+    @Override
+    public abstract long millis();
+
+    @Override
+    public Instant instant() {
+        return Instant.ofEpochMilli(millis());
+    }
+}
diff --git a/core/java/android/os/SystemClock.java b/core/java/android/os/SystemClock.java
index c52c22d..0f70427 100644
--- a/core/java/android/os/SystemClock.java
+++ b/core/java/android/os/SystemClock.java
@@ -24,8 +24,7 @@
 import dalvik.annotation.optimization.CriticalNative;
 
 import java.time.Clock;
-import java.time.Instant;
-import java.time.ZoneId;
+import java.time.DateTimeException;
 import java.time.ZoneOffset;
 
 /**
@@ -148,8 +147,8 @@
      * @return if the clock was successfully set to the specified time.
      */
     public static boolean setCurrentTimeMillis(long millis) {
-        IBinder b = ServiceManager.getService(Context.ALARM_SERVICE);
-        IAlarmManager mgr = IAlarmManager.Stub.asInterface(b);
+        final IAlarmManager mgr = IAlarmManager.Stub
+                .asInterface(ServiceManager.getService(Context.ALARM_SERVICE));
         if (mgr == null) {
             return false;
         }
@@ -174,27 +173,25 @@
     native public static long uptimeMillis();
 
     /**
+     * @removed
+     */
+    @Deprecated
+    public static @NonNull Clock uptimeMillisClock() {
+        return uptimeClock();
+    }
+
+    /**
      * Return {@link Clock} that starts at system boot, not counting time spent
      * in deep sleep.
+     *
+     * @removed
      */
-    public static @NonNull Clock uptimeMillisClock() {
-        return new Clock() {
-            @Override
-            public ZoneId getZone() {
-                return ZoneOffset.UTC;
-            }
-            @Override
-            public Clock withZone(ZoneId zone) {
-                throw new UnsupportedOperationException();
-            }
+    public static @NonNull Clock uptimeClock() {
+        return new SimpleClock(ZoneOffset.UTC) {
             @Override
             public long millis() {
                 return SystemClock.uptimeMillis();
             }
-            @Override
-            public Instant instant() {
-                return Instant.ofEpochMilli(millis());
-            }
         };
     }
 
@@ -209,25 +206,15 @@
     /**
      * Return {@link Clock} that starts at system boot, including time spent in
      * sleep.
+     *
+     * @removed
      */
     public static @NonNull Clock elapsedRealtimeClock() {
-        return new Clock() {
-            @Override
-            public ZoneId getZone() {
-                return ZoneOffset.UTC;
-            }
-            @Override
-            public Clock withZone(ZoneId zone) {
-                throw new UnsupportedOperationException();
-            }
+        return new SimpleClock(ZoneOffset.UTC) {
             @Override
             public long millis() {
                 return SystemClock.elapsedRealtime();
             }
-            @Override
-            public Instant instant() {
-                return Instant.ofEpochMilli(millis());
-            }
         };
     }
 
@@ -266,4 +253,62 @@
      */
     @CriticalNative
     public static native long currentTimeMicro();
+
+    /**
+     * Returns milliseconds since January 1, 1970 00:00:00.0 UTC, synchronized
+     * using a remote network source outside the device.
+     * <p>
+     * While the time returned by {@link System#currentTimeMillis()} can be
+     * adjusted by the user, the time returned by this method cannot be adjusted
+     * by the user. Note that synchronization may occur using an insecure
+     * network protocol, so the returned time should not be used for security
+     * purposes.
+     * <p>
+     * This performs no blocking network operations and returns values based on
+     * a recent successful synchronization event; it will either return a valid
+     * time or throw.
+     *
+     * @throws DateTimeException when no accurate network time can be provided.
+     */
+    public static long currentNetworkTimeMillis() {
+        final IAlarmManager mgr = IAlarmManager.Stub
+                .asInterface(ServiceManager.getService(Context.ALARM_SERVICE));
+        if (mgr != null) {
+            try {
+                return mgr.currentNetworkTimeMillis();
+            } catch (ParcelableException e) {
+                e.maybeRethrow(DateTimeException.class);
+                throw new RuntimeException(e);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        } else {
+            throw new RuntimeException(new DeadSystemException());
+        }
+    }
+
+    /**
+     * Returns a {@link Clock} that starts at January 1, 1970 00:00:00.0 UTC,
+     * synchronized using a remote network source outside the device.
+     * <p>
+     * While the time returned by {@link System#currentTimeMillis()} can be
+     * adjusted by the user, the time returned by this method cannot be adjusted
+     * by the user. Note that synchronization may occur using an insecure
+     * network protocol, so the returned time should not be used for security
+     * purposes.
+     * <p>
+     * This performs no blocking network operations and returns values based on
+     * a recent successful synchronization event; it will either return a valid
+     * time or throw.
+     *
+     * @throws DateTimeException when no accurate network time can be provided.
+     */
+    public static @NonNull Clock currentNetworkTimeClock() {
+        return new SimpleClock(ZoneOffset.UTC) {
+            @Override
+            public long millis() {
+                return SystemClock.currentNetworkTimeMillis();
+            }
+        };
+    }
 }
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index c53d005..c6baec9 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -8760,6 +8760,7 @@
        /** {@hide} */
        public static final String NETSTATS_POLL_INTERVAL = "netstats_poll_interval";
        /** {@hide} */
+       @Deprecated
        public static final String NETSTATS_TIME_CACHE_MAX_AGE = "netstats_time_cache_max_age";
        /** {@hide} */
        public static final String NETSTATS_GLOBAL_ALERT_BYTES = "netstats_global_alert_bytes";
diff --git a/services/core/java/com/android/server/AlarmManagerService.java b/services/core/java/com/android/server/AlarmManagerService.java
index a422b7c..9cd3621 100644
--- a/services/core/java/com/android/server/AlarmManagerService.java
+++ b/services/core/java/com/android/server/AlarmManagerService.java
@@ -16,6 +16,13 @@
 
 package com.android.server;
 
+import static android.app.AlarmManager.ELAPSED_REALTIME;
+import static android.app.AlarmManager.ELAPSED_REALTIME_WAKEUP;
+import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE;
+import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED;
+import static android.app.AlarmManager.RTC;
+import static android.app.AlarmManager.RTC_WAKEUP;
+
 import android.annotation.UserIdInt;
 import android.app.Activity;
 import android.app.ActivityManager;
@@ -46,6 +53,7 @@
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Message;
+import android.os.ParcelableException;
 import android.os.PowerManager;
 import android.os.Process;
 import android.os.RemoteException;
@@ -62,6 +70,7 @@
 import android.util.ArraySet;
 import android.util.KeyValueListParser;
 import android.util.Log;
+import android.util.NtpTrustedTime;
 import android.util.Pair;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -70,10 +79,18 @@
 import android.util.TimeUtils;
 import android.util.proto.ProtoOutputStream;
 
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.ArrayUtils;
+import com.android.internal.util.DumpUtils;
+import com.android.internal.util.LocalLog;
+import com.android.server.AppStateTracker.Listener;
+
 import java.io.ByteArrayOutputStream;
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.text.SimpleDateFormat;
+import java.time.DateTimeException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
@@ -88,21 +105,6 @@
 import java.util.TreeSet;
 import java.util.function.Predicate;
 
-import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE;
-import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED;
-import static android.app.AlarmManager.RTC_WAKEUP;
-import static android.app.AlarmManager.RTC;
-import static android.app.AlarmManager.ELAPSED_REALTIME_WAKEUP;
-import static android.app.AlarmManager.ELAPSED_REALTIME;
-
-import com.android.internal.annotations.GuardedBy;
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.ArrayUtils;
-import com.android.internal.util.DumpUtils;
-import com.android.internal.util.LocalLog;
-import com.android.internal.util.Preconditions;
-import com.android.server.AppStateTracker.Listener;
-
 /**
  * Alarm manager implementaion.
  *
@@ -1794,6 +1796,16 @@
         }
 
         @Override
+        public long currentNetworkTimeMillis() {
+            final NtpTrustedTime time = NtpTrustedTime.getInstance(getContext());
+            if (time.hasCache()) {
+                return time.currentTimeMillis();
+            } else {
+                throw new ParcelableException(new DateTimeException("Missing NTP fix"));
+            }
+        }
+
+        @Override
         protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
             if (!DumpUtils.checkDumpAndUsageStatsPermission(getContext(), TAG, pw)) return;
 
diff --git a/services/core/java/com/android/server/NetworkTimeUpdateService.java b/services/core/java/com/android/server/NetworkTimeUpdateService.java
index 2c24798..b3a8fb6 100644
--- a/services/core/java/com/android/server/NetworkTimeUpdateService.java
+++ b/services/core/java/com/android/server/NetworkTimeUpdateService.java
@@ -23,7 +23,6 @@
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.content.pm.PackageManager;
 import android.database.ContentObserver;
 import android.net.ConnectivityManager;
 import android.net.ConnectivityManager.NetworkCallback;
@@ -33,13 +32,12 @@
 import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Message;
-import android.os.SystemClock;
 import android.os.PowerManager;
+import android.os.SystemClock;
 import android.provider.Settings;
 import android.util.Log;
 import android.util.NtpTrustedTime;
 import android.util.TimeUtils;
-import android.util.TrustedTime;
 
 import com.android.internal.telephony.TelephonyIntents;
 import com.android.internal.util.DumpUtils;
@@ -75,19 +73,17 @@
     private long mNitzTimeSetTime = NOT_SET;
     private Network mDefaultNetwork = null;
 
-    private Context mContext;
-    private TrustedTime mTime;
+    private final Context mContext;
+    private final NtpTrustedTime mTime;
+    private final AlarmManager mAlarmManager;
+    private final ConnectivityManager mCM;
+    private final PendingIntent mPendingPollIntent;
+    private final PowerManager.WakeLock mWakeLock;
 
     // NTP lookup is done on this thread and handler
     private Handler mHandler;
-    private AlarmManager mAlarmManager;
-    private PendingIntent mPendingPollIntent;
     private SettingsObserver mSettingsObserver;
-    private ConnectivityManager mCM;
     private NetworkTimeUpdateCallback mNetworkTimeUpdateCallback;
-    // The last time that we successfully fetched the NTP time.
-    private long mLastNtpFetchTime = NOT_SET;
-    private final PowerManager.WakeLock mWakeLock;
 
     // Normal polling frequency
     private final long mPollingIntervalMs;
@@ -105,8 +101,9 @@
     public NetworkTimeUpdateService(Context context) {
         mContext = context;
         mTime = NtpTrustedTime.getInstance(context);
-        mAlarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
-        mCM = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
+        mAlarmManager = mContext.getSystemService(AlarmManager.class);
+        mCM = mContext.getSystemService(ConnectivityManager.class);
+
         Intent pollIntent = new Intent(ACTION_POLL, null);
         mPendingPollIntent = PendingIntent.getBroadcast(mContext, POLL_REQUEST, pollIntent, 0);
 
@@ -119,7 +116,7 @@
         mTimeErrorThresholdMs = mContext.getResources().getInteger(
                 com.android.internal.R.integer.config_ntpThreshold);
 
-        mWakeLock = ((PowerManager) context.getSystemService(Context.POWER_SERVICE)).newWakeLock(
+        mWakeLock = context.getSystemService(PowerManager.class).newWakeLock(
                 PowerManager.PARTIAL_WAKE_LOCK, TAG);
     }
 
@@ -157,7 +154,7 @@
     private void onPollNetworkTime(int event) {
         // If Automatic time is not set, don't bother. Similarly, if we don't
         // have any default network, don't bother.
-        if (!isAutomaticTimeRequested() || mDefaultNetwork == null) return;
+        if (mDefaultNetwork == null) return;
         mWakeLock.acquire();
         try {
             onPollNetworkTimeUnderWakeLock(event);
@@ -167,61 +164,60 @@
     }
 
     private void onPollNetworkTimeUnderWakeLock(int event) {
-        final long refTime = SystemClock.elapsedRealtime();
-        // If NITZ time was received less than mPollingIntervalMs time ago,
-        // no need to sync to NTP.
-        if (mNitzTimeSetTime != NOT_SET && refTime - mNitzTimeSetTime < mPollingIntervalMs) {
-            resetAlarm(mPollingIntervalMs);
-            return;
+        // Force an NTP fix when outdated
+        if (mTime.getCacheAge() >= mPollingIntervalMs) {
+            if (DBG) Log.d(TAG, "Stale NTP fix; forcing refresh");
+            mTime.forceRefresh();
         }
-        final long currentTime = System.currentTimeMillis();
-        if (DBG) Log.d(TAG, "System time = " + currentTime);
-        // Get the NTP time
-        if (mLastNtpFetchTime == NOT_SET || refTime >= mLastNtpFetchTime + mPollingIntervalMs
-                || event == EVENT_AUTO_TIME_CHANGED) {
-            if (DBG) Log.d(TAG, "Before Ntp fetch");
 
-            // force refresh NTP cache when outdated
-            if (mTime.getCacheAge() >= mPollingIntervalMs) {
-                mTime.forceRefresh();
+        if (mTime.getCacheAge() < mPollingIntervalMs) {
+            // Obtained fresh fix; schedule next normal update
+            resetAlarm(mPollingIntervalMs);
+            if (isAutomaticTimeRequested()) {
+                updateSystemClock(event);
             }
 
-            // only update when NTP time is fresh
-            if (mTime.getCacheAge() < mPollingIntervalMs) {
-                final long ntp = mTime.currentTimeMillis();
-                mTryAgainCounter = 0;
-                // If the clock is more than N seconds off or this is the first time it's been
-                // fetched since boot, set the current time.
-                if (Math.abs(ntp - currentTime) > mTimeErrorThresholdMs
-                        || mLastNtpFetchTime == NOT_SET) {
-                    // Set the system time
-                    if (DBG && mLastNtpFetchTime == NOT_SET
-                            && Math.abs(ntp - currentTime) <= mTimeErrorThresholdMs) {
-                        Log.d(TAG, "For initial setup, rtc = " + currentTime);
-                    }
-                    if (DBG) Log.d(TAG, "Ntp time to be set = " + ntp);
-                    // Make sure we don't overflow, since it's going to be converted to an int
-                    if (ntp / 1000 < Integer.MAX_VALUE) {
-                        SystemClock.setCurrentTimeMillis(ntp);
-                    }
-                } else {
-                    if (DBG) Log.d(TAG, "Ntp time is close enough = " + ntp);
-                }
-                mLastNtpFetchTime = SystemClock.elapsedRealtime();
+        } else {
+            // No fresh fix; schedule retry
+            mTryAgainCounter++;
+            if (mTryAgainTimesMax < 0 || mTryAgainCounter <= mTryAgainTimesMax) {
+                resetAlarm(mPollingIntervalShorterMs);
             } else {
-                // Try again shortly
-                mTryAgainCounter++;
-                if (mTryAgainTimesMax < 0 || mTryAgainCounter <= mTryAgainTimesMax) {
-                    resetAlarm(mPollingIntervalShorterMs);
-                } else {
-                    // Try much later
-                    mTryAgainCounter = 0;
-                    resetAlarm(mPollingIntervalMs);
-                }
+                // Try much later
+                mTryAgainCounter = 0;
+                resetAlarm(mPollingIntervalMs);
+            }
+        }
+    }
+
+    private long getNitzAge() {
+        if (mNitzTimeSetTime == NOT_SET) {
+            return Long.MAX_VALUE;
+        } else {
+            return SystemClock.elapsedRealtime() - mNitzTimeSetTime;
+        }
+    }
+
+    /**
+     * Consider updating system clock based on current NTP fix, if requested by
+     * user, significant enough delta, and we don't have a recent NITZ.
+     */
+    private void updateSystemClock(int event) {
+        final boolean forceUpdate = (event == EVENT_AUTO_TIME_CHANGED);
+        if (!forceUpdate) {
+            if (getNitzAge() < mPollingIntervalMs) {
+                if (DBG) Log.d(TAG, "Ignoring NTP update due to recent NITZ");
+                return;
+            }
+
+            final long skew = Math.abs(mTime.currentTimeMillis() - System.currentTimeMillis());
+            if (skew < mTimeErrorThresholdMs) {
+                if (DBG) Log.d(TAG, "Ignoring NTP update due to low skew");
                 return;
             }
         }
-        resetAlarm(mPollingIntervalMs);
+
+        SystemClock.setCurrentTimeMillis(mTime.currentTimeMillis());
     }
 
     /**
@@ -326,8 +322,8 @@
         pw.print("TimeErrorThresholdMs: ");
         TimeUtils.formatDuration(mTimeErrorThresholdMs, pw);
         pw.println("\nTryAgainCounter: " + mTryAgainCounter);
-        pw.print("LastNtpFetchTime: ");
-        TimeUtils.formatDuration(mLastNtpFetchTime, pw);
+        pw.println("NTP cache age: " + mTime.getCacheAge());
+        pw.println("NTP cache certainty: " + mTime.getCacheCertainty());
         pw.println();
     }
 }
diff --git a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
index e2b2d46..bd9ec55 100644
--- a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
+++ b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
@@ -147,6 +147,7 @@
 import android.os.Binder;
 import android.os.Build;
 import android.os.Environment;
+import android.os.BestClock;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.IDeviceIdleController;
@@ -164,6 +165,7 @@
 import android.os.ResultReceiver;
 import android.os.ServiceManager;
 import android.os.ShellCallback;
+import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
@@ -183,7 +185,6 @@
 import android.util.AtomicFile;
 import android.util.DataUnit;
 import android.util.Log;
-import android.util.NtpTrustedTime;
 import android.util.Pair;
 import android.util.RecurrenceRule;
 import android.util.Slog;
@@ -191,7 +192,6 @@
 import android.util.SparseBooleanArray;
 import android.util.SparseIntArray;
 import android.util.SparseLongArray;
-import android.util.TrustedTime;
 import android.util.Xml;
 
 import com.android.internal.R;
@@ -226,7 +226,9 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.nio.charset.StandardCharsets;
+import java.time.Clock;
 import java.time.ZoneId;
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Calendar;
@@ -335,8 +337,6 @@
     private static final String ACTION_SNOOZE_RAPID =
             "com.android.server.net.action.SNOOZE_RAPID";
 
-    private static final long TIME_CACHE_MAX_AGE = DAY_IN_MILLIS;
-
     /**
      * Indicates the maximum wait time for admin data to be available;
      */
@@ -362,7 +362,7 @@
     private final INetworkStatsService mNetworkStats;
     private final INetworkManagementService mNetworkManager;
     private UsageStatsManagerInternal mUsageStats;
-    private final TrustedTime mTime;
+    private final Clock mClock;
     private final UserManager mUserManager;
     private final CarrierConfigManager mCarrierConfigManager;
 
@@ -518,24 +518,29 @@
     public NetworkPolicyManagerService(Context context, IActivityManager activityManager,
             INetworkStatsService networkStats, INetworkManagementService networkManagement) {
         this(context, activityManager, networkStats, networkManagement,
-                AppGlobals.getPackageManager(), NtpTrustedTime.getInstance(context), getSystemDir(),
+                AppGlobals.getPackageManager(), getDefaultClock(), getDefaultSystemDir(),
                 false);
     }
 
-    private static File getSystemDir() {
+    private static @NonNull File getDefaultSystemDir() {
         return new File(Environment.getDataDirectory(), "system");
     }
 
+    private static @NonNull Clock getDefaultClock() {
+        return new BestClock(ZoneOffset.UTC, SystemClock.currentNetworkTimeClock(),
+                Clock.systemUTC());
+    }
+
     public NetworkPolicyManagerService(Context context, IActivityManager activityManager,
             INetworkStatsService networkStats, INetworkManagementService networkManagement,
-            IPackageManager pm, TrustedTime time, File systemDir, boolean suppressDefaultPolicy) {
+            IPackageManager pm, Clock clock, File systemDir, boolean suppressDefaultPolicy) {
         mContext = checkNotNull(context, "missing context");
         mActivityManager = checkNotNull(activityManager, "missing activityManager");
         mNetworkStats = checkNotNull(networkStats, "missing networkStats");
         mNetworkManager = checkNotNull(networkManagement, "missing networkManagement");
         mDeviceIdleController = IDeviceIdleController.Stub.asInterface(ServiceManager.getService(
                 Context.DEVICE_IDLE_CONTROLLER));
-        mTime = checkNotNull(time, "missing TrustedTime");
+        mClock = checkNotNull(clock, "missing Clock");
         mUserManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
         mCarrierConfigManager = mContext.getSystemService(CarrierConfigManager.class);
         mIPm = pm;
@@ -932,7 +937,6 @@
             // on background handler thread, and verified
             // READ_NETWORK_USAGE_HISTORY permission above.
 
-            maybeRefreshTrustedTime();
             synchronized (mNetworkPoliciesSecondLock) {
                 updateNetworkEnabledNL();
                 updateNotificationsNL();
@@ -1042,7 +1046,7 @@
         // cycle boundary to recompute notifications.
 
         // examine stats for each active policy
-        final long now = currentTimeMillis();
+        final long now = mClock.millis();
         for (int i = mNetworkPolicy.size()-1; i >= 0; i--) {
             final NetworkPolicy policy = mNetworkPolicy.valueAt(i);
             // ignore policies that aren't relevant to user
@@ -1299,7 +1303,6 @@
             // on background handler thread, and verified CONNECTIVITY_INTERNAL
             // permission above.
 
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     ensureActiveMobilePolicyAL();
@@ -1462,7 +1465,6 @@
             final TelephonyManager tele = mContext.getSystemService(TelephonyManager.class);
             final String subscriberId = tele.getSubscriberId(subId);
 
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     final boolean added = ensureActiveMobilePolicyAL(subId, subscriberId);
@@ -1723,7 +1725,7 @@
                 final long totalBytes = getTotalBytes(
                         NetworkTemplate.buildTemplateMobileAll(state.subscriberId), start, end);
                 final long remainingBytes = limitBytes - totalBytes;
-                final long remainingDays = Math.max(1, (end - currentTimeMillis())
+                final long remainingDays = Math.max(1, (end - mClock.millis())
                         / TimeUnit.DAYS.toMillis(1));
                 if (remainingBytes > 0) {
                     quotaBytes = (remainingBytes / remainingDays) / 10;
@@ -2444,7 +2446,6 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     normalizePoliciesNL(policies);
@@ -2524,8 +2525,7 @@
     }
 
     void performSnooze(NetworkTemplate template, int type) {
-        maybeRefreshTrustedTime();
-        final long currentTime = currentTimeMillis();
+        final long currentTime = mClock.millis();
         synchronized (mUidRulesFirstLock) {
             synchronized (mNetworkPoliciesSecondLock) {
                 // find and snooze local policy that matches
@@ -2571,7 +2571,6 @@
             mContext.enforceCallingOrSelfPermission(MANAGE_NETWORK_POLICY, TAG);
             final long token = Binder.clearCallingIdentity();
             try {
-                maybeRefreshTrustedTime();
                 synchronized (mUidRulesFirstLock) {
                     setRestrictBackgroundUL(restrictBackground);
                 }
@@ -2916,7 +2915,6 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     mSubscriptionPlans.put(subId, plans);
@@ -4028,7 +4026,6 @@
                 case MSG_LIMIT_REACHED: {
                     final String iface = (String) msg.obj;
 
-                    maybeRefreshTrustedTime();
                     synchronized (mNetworkPoliciesSecondLock) {
                         if (mMeteredIfaces.contains(iface)) {
                             try {
@@ -4393,19 +4390,6 @@
         }
     }
 
-    /**
-     * Try refreshing {@link #mTime} when stale.
-     */
-    void maybeRefreshTrustedTime() {
-        if (mTime.getCacheAge() > TIME_CACHE_MAX_AGE) {
-            mTime.forceRefresh();
-        }
-    }
-
-    private long currentTimeMillis() {
-        return mTime.hasCache() ? mTime.currentTimeMillis() : System.currentTimeMillis();
-    }
-
     private static Intent buildAllowBackgroundDataIntent() {
         return new Intent(ACTION_ALLOW_BACKGROUND);
     }
diff --git a/services/core/java/com/android/server/net/NetworkStatsService.java b/services/core/java/com/android/server/net/NetworkStatsService.java
index 76c4db1..d1aa212 100644
--- a/services/core/java/com/android/server/net/NetworkStatsService.java
+++ b/services/core/java/com/android/server/net/NetworkStatsService.java
@@ -68,6 +68,7 @@
 import static com.android.server.NetworkManagementSocketTagger.resetKernelUidStats;
 import static com.android.server.NetworkManagementSocketTagger.setKernelCounterSet;
 
+import android.annotation.NonNull;
 import android.app.AlarmManager;
 import android.app.PendingIntent;
 import android.app.usage.NetworkStatsManager;
@@ -97,6 +98,7 @@
 import android.os.Binder;
 import android.os.DropBoxManager;
 import android.os.Environment;
+import android.os.BestClock;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.IBinder;
@@ -120,10 +122,8 @@
 import android.util.EventLog;
 import android.util.Log;
 import android.util.MathUtils;
-import android.util.NtpTrustedTime;
 import android.util.Slog;
 import android.util.SparseIntArray;
-import android.util.TrustedTime;
 import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.annotations.GuardedBy;
@@ -140,6 +140,8 @@
 import java.io.FileDescriptor;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.time.Clock;
+import java.time.ZoneOffset;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
@@ -167,7 +169,7 @@
     private final Context mContext;
     private final INetworkManagementService mNetworkManager;
     private final AlarmManager mAlarmManager;
-    private final TrustedTime mTime;
+    private final Clock mClock;
     private final TelephonyManager mTeleManager;
     private final NetworkStatsSettings mSettings;
     private final NetworkStatsObservers mStatsObservers;
@@ -202,7 +204,6 @@
      */
     public interface NetworkStatsSettings {
         public long getPollInterval();
-        public long getTimeCacheMaxAge();
         public boolean getSampleEnabled();
         public boolean getAugmentEnabled();
 
@@ -281,16 +282,21 @@
     private long mPersistThreshold = 2 * MB_IN_BYTES;
     private long mGlobalAlertBytes;
 
-    private static File getDefaultSystemDir() {
+    private static @NonNull File getDefaultSystemDir() {
         return new File(Environment.getDataDirectory(), "system");
     }
 
-    private static File getDefaultBaseDir() {
+    private static @NonNull File getDefaultBaseDir() {
         File baseDir = new File(getDefaultSystemDir(), "netstats");
         baseDir.mkdirs();
         return baseDir;
     }
 
+    private static @NonNull Clock getDefaultClock() {
+        return new BestClock(ZoneOffset.UTC, SystemClock.currentNetworkTimeClock(),
+                Clock.systemUTC());
+    }
+
     public static NetworkStatsService create(Context context,
                 INetworkManagementService networkManager) {
         AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
@@ -299,7 +305,7 @@
                 powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
 
         NetworkStatsService service = new NetworkStatsService(context, networkManager, alarmManager,
-                wakeLock, NtpTrustedTime.getInstance(context), TelephonyManager.getDefault(),
+                wakeLock, getDefaultClock(), TelephonyManager.getDefault(),
                 new DefaultNetworkStatsSettings(context), new NetworkStatsObservers(),
                 getDefaultSystemDir(), getDefaultBaseDir());
 
@@ -313,13 +319,13 @@
 
     @VisibleForTesting
     NetworkStatsService(Context context, INetworkManagementService networkManager,
-            AlarmManager alarmManager, PowerManager.WakeLock wakeLock, TrustedTime time,
+            AlarmManager alarmManager, PowerManager.WakeLock wakeLock, Clock clock,
             TelephonyManager teleManager, NetworkStatsSettings settings,
             NetworkStatsObservers statsObservers, File systemDir, File baseDir) {
         mContext = checkNotNull(context, "missing Context");
         mNetworkManager = checkNotNull(networkManager, "missing INetworkManagementService");
         mAlarmManager = checkNotNull(alarmManager, "missing AlarmManager");
-        mTime = checkNotNull(time, "missing TrustedTime");
+        mClock = checkNotNull(clock, "missing Clock");
         mSettings = checkNotNull(settings, "missing NetworkStatsSettings");
         mTeleManager = checkNotNull(teleManager, "missing TelephonyManager");
         mWakeLock = checkNotNull(wakeLock, "missing WakeLock");
@@ -413,8 +419,7 @@
         mContext.unregisterReceiver(mUserReceiver);
         mContext.unregisterReceiver(mShutdownReceiver);
 
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
 
         // persist any pending stats
         mDevRecorder.forcePersistLocked(currentTime);
@@ -831,8 +836,7 @@
         }
 
         // update and persist if beyond new thresholds
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
         synchronized (mStatsLock) {
             if (!mSystemReady) return;
 
@@ -1170,8 +1174,7 @@
      */
     @GuardedBy("mStatsLock")
     private void bootstrapStatsLocked() {
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
 
         try {
             recordSnapshotLocked(currentTime);
@@ -1183,11 +1186,6 @@
     }
 
     private void performPoll(int flags) {
-        // try refreshing time source when stale
-        if (mTime.getCacheAge() > mSettings.getTimeCacheMaxAge()) {
-            mTime.forceRefresh();
-        }
-
         synchronized (mStatsLock) {
             mWakeLock.acquire();
 
@@ -1215,8 +1213,7 @@
         final boolean persistForce = (flags & FLAG_PERSIST_FORCE) != 0;
 
         // TODO: consider marking "untrusted" times in historical stats
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
 
         try {
             recordSnapshotLocked(currentTime);
@@ -1268,7 +1265,7 @@
     @GuardedBy("mStatsLock")
     private void performSampleLocked() {
         // TODO: migrate trustedtime fixes to separate binary log events
-        final long trustedTime = mTime.hasCache() ? mTime.currentTimeMillis() : -1;
+        final long currentTime = mClock.millis();
 
         NetworkTemplate template;
         NetworkStats.Entry devTotal;
@@ -1285,7 +1282,7 @@
                 devTotal.rxBytes, devTotal.rxPackets, devTotal.txBytes, devTotal.txPackets,
                 xtTotal.rxBytes, xtTotal.rxPackets, xtTotal.txBytes, xtTotal.txPackets,
                 uidTotal.rxBytes, uidTotal.rxPackets, uidTotal.txBytes, uidTotal.txPackets,
-                trustedTime);
+                currentTime);
 
         // collect wifi sample
         template = buildTemplateWifiWildcard();
@@ -1297,7 +1294,7 @@
                 devTotal.rxBytes, devTotal.rxPackets, devTotal.txBytes, devTotal.txPackets,
                 xtTotal.rxBytes, xtTotal.rxPackets, xtTotal.txBytes, xtTotal.txPackets,
                 uidTotal.rxBytes, uidTotal.rxPackets, uidTotal.txBytes, uidTotal.txPackets,
-                trustedTime);
+                currentTime);
     }
 
     /**
@@ -1621,10 +1618,6 @@
             return getGlobalLong(NETSTATS_POLL_INTERVAL, 30 * MINUTE_IN_MILLIS);
         }
         @Override
-        public long getTimeCacheMaxAge() {
-            return getGlobalLong(NETSTATS_TIME_CACHE_MAX_AGE, DAY_IN_MILLIS);
-        }
-        @Override
         public long getGlobalAlertBytes(long def) {
             return getGlobalLong(NETSTATS_GLOBAL_ALERT_BYTES, def);
         }
diff --git a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
index 184e8de..e1b4422 100644
--- a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
@@ -104,6 +104,7 @@
 import android.os.PowerManagerInternal;
 import android.os.PowerSaveState;
 import android.os.RemoteException;
+import android.os.SimpleClock;
 import android.os.UserHandle;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.runner.AndroidJUnit4;
@@ -118,7 +119,6 @@
 import android.util.Log;
 import android.util.Pair;
 import android.util.RecurrenceRule;
-import android.util.TrustedTime;
 
 import com.android.internal.telephony.PhoneConstants;
 import com.android.internal.util.test.BroadcastInterceptingContext;
@@ -158,6 +158,7 @@
 import java.time.Instant;
 import java.time.Period;
 import java.time.ZoneId;
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.Arrays;
 import java.util.Calendar;
@@ -215,7 +216,6 @@
     private @Mock IActivityManager mActivityManager;
     private @Mock INetworkStatsService mStatsService;
     private @Mock INetworkManagementService mNetworkManager;
-    private @Mock TrustedTime mTime;
     private @Mock IConnectivityManager mConnManager;
     private @Mock NotificationManager mNotifManager;
     private @Mock PackageManager mPackageManager;
@@ -267,6 +267,13 @@
 
     public final @Rule NetPolicyMethodRule mNetPolicyXmlRule = new NetPolicyMethodRule();
 
+    private final Clock mClock = new SimpleClock(ZoneOffset.UTC) {
+        @Override
+        public long millis() {
+            return currentTimeMillis();
+        }
+    };
+
     private void registerLocalServices() {
         addLocalServiceMock(DeviceIdleController.LocalService.class);
 
@@ -341,7 +348,7 @@
 
         mFutureIntent = newRestrictBackgroundChangedFuture();
         mService = new NetworkPolicyManagerService(mServiceContext, mActivityManager, mStatsService,
-                mNetworkManager, mIpm, mTime, mPolicyDir, true);
+                mNetworkManager, mIpm, mClock, mPolicyDir, true);
         mService.bindConnectivityManager(mConnManager);
         mPolicyListener = new NetworkPolicyListenerAnswer(mService);
 
@@ -370,7 +377,6 @@
         when(mPackageManager.getPackagesForUid(UID_A)).thenReturn(new String[] {PKG_NAME_A});
         when(mNetworkManager.isBandwidthControlEnabled()).thenReturn(true);
         when(mNetworkManager.setDataSaverModeEnabled(anyBoolean())).thenReturn(true);
-        expectCurrentTime();
 
         // Prepare NPMS.
         mService.systemReady(mService.networkScoreAndNetworkManagementServiceReady());
@@ -940,7 +946,6 @@
         // which means we shouldn't push limit to interface.
         state = new NetworkState[] { buildWifi() };
         when(mConnManager.getAllNetworkState()).thenReturn(state);
-        expectCurrentTime();
 
         mPolicyListener.expect().onMeteredIfacesChanged(any());
         mServiceContext.sendBroadcast(new Intent(CONNECTIVITY_ACTION));
@@ -949,7 +954,6 @@
         // now change cycle to be on 15th, and test in early march, to verify we
         // pick cycle day in previous month.
         when(mConnManager.getAllNetworkState()).thenReturn(state);
-        expectCurrentTime();
 
         // pretend that 512 bytes total have happened
         stats = new NetworkStats(getElapsedRealtime(), 1)
@@ -996,7 +1000,6 @@
         final long start = parseTime("2015-11-01T00:00Z");
         final long end = parseTime("2015-11-07T00:00Z");
         setCurrentTimeMillis(end);
-        expectCurrentTime();
 
         // Normal usage means no notification
         {
@@ -1096,7 +1099,6 @@
         final long start = parseTime("2015-11-01T00:00Z");
         final long end = parseTime("2015-11-07T00:00Z");
         setCurrentTimeMillis(end);
-        expectCurrentTime();
 
         // Using 20% data in 20% time is normal
         {
@@ -1139,7 +1141,6 @@
                 .addIfaceValues(TEST_IFACE, 0L, 0L, 0L, 0L);
 
         {
-            expectCurrentTime();
             when(mConnManager.getAllNetworkState()).thenReturn(state);
             when(mStatsService.getNetworkTotalBytes(sTemplateWifi, TIME_FEB_15,
                     currentTimeMillis())).thenReturn(stats.getTotalBytes());
@@ -1474,14 +1475,6 @@
         return new NetworkState(info, prop, networkCapabilities, null, null, TEST_SSID);
     }
 
-    private void expectCurrentTime() throws Exception {
-        when(mTime.forceRefresh()).thenReturn(false);
-        when(mTime.hasCache()).thenReturn(true);
-        when(mTime.currentTimeMillis()).thenReturn(currentTimeMillis());
-        when(mTime.getCacheAge()).thenReturn(0L);
-        when(mTime.getCacheCertainty()).thenReturn(0L);
-    }
-
     private void expectHasInternetPermission(int uid, boolean hasIt) throws Exception {
         when(mIpm.checkUidPermission(Manifest.permission.INTERNET, uid)).thenReturn(
                 hasIt ? PackageManager.PERMISSION_GRANTED : PackageManager.PERMISSION_DENIED);
diff --git a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
index 0f26edb..b1b05e8 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -87,12 +87,11 @@
 import android.os.Message;
 import android.os.Messenger;
 import android.os.PowerManager;
+import android.os.SimpleClock;
 import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
 import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
 import android.telephony.TelephonyManager;
-import android.util.Log;
-import android.util.TrustedTime;
 
 import com.android.internal.net.VpnInfo;
 import com.android.internal.util.test.BroadcastInterceptingContext;
@@ -111,6 +110,8 @@
 import org.mockito.MockitoAnnotations;
 
 import java.io.File;
+import java.time.Clock;
+import java.time.ZoneOffset;
 import java.util.Objects;
 
 /**
@@ -155,7 +156,6 @@
     private File mStatsDir;
 
     private @Mock INetworkManagementService mNetManager;
-    private @Mock TrustedTime mTime;
     private @Mock NetworkStatsSettings mSettings;
     private @Mock IConnectivityManager mConnManager;
     private @Mock IBinder mBinder;
@@ -167,6 +167,13 @@
     private INetworkStatsSession mSession;
     private INetworkManagementEventObserver mNetworkObserver;
 
+    private final Clock mClock = new SimpleClock(ZoneOffset.UTC) {
+        @Override
+        public long millis() {
+            return currentTimeMillis();
+        }
+    };
+
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
@@ -184,7 +191,7 @@
                 powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
 
         mService = new NetworkStatsService(
-                mServiceContext, mNetManager, mAlarmManager, wakeLock, mTime,
+                mServiceContext, mNetManager, mAlarmManager, wakeLock, mClock,
                 TelephonyManager.getDefault(), mSettings, new NetworkStatsObservers(),
                 mStatsDir, getBaseDir(mStatsDir));
         mHandlerThread = new HandlerThread("HandlerThread");
@@ -196,7 +203,6 @@
 
         mElapsedRealtime = 0L;
 
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectSystemReady();
@@ -221,7 +227,6 @@
         mStatsDir = null;
 
         mNetManager = null;
-        mTime = null;
         mSettings = null;
         mConnManager = null;
 
@@ -233,7 +238,6 @@
     public void testNetworkStatsWifi() throws Exception {
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -248,7 +252,6 @@
 
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 1024L, 1L, 2048L, 2L));
@@ -262,7 +265,6 @@
         // and bump forward again, with counters going higher. this is
         // important, since polling should correctly subtract last snapshot.
         incrementCurrentTime(DAY_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4096L, 4L, 8192L, 8L));
@@ -280,7 +282,6 @@
 
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -295,7 +296,6 @@
 
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 1024L, 8L, 2048L, 16L));
@@ -324,13 +324,11 @@
 
         // graceful shutdown system, which should trigger persist of stats, and
         // clear any values in memory.
-        expectCurrentTime();
         expectDefaultSettings();
         mServiceContext.sendBroadcast(new Intent(Intent.ACTION_SHUTDOWN));
         assertStatsFilesExist(true);
 
         // boot through serviceReady() again
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectSystemReady();
@@ -358,7 +356,6 @@
 
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectSettings(0L, HOUR_IN_MILLIS, WEEK_IN_MILLIS);
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -370,7 +367,6 @@
 
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(2 * HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectSettings(0L, HOUR_IN_MILLIS, WEEK_IN_MILLIS);
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 512L, 4L, 512L, 4L));
@@ -386,7 +382,6 @@
 
         // now change bucket duration setting and trigger another poll with
         // exact same values, which should resize existing buckets.
-        expectCurrentTime();
         expectSettings(0L, 30 * MINUTE_IN_MILLIS, WEEK_IN_MILLIS);
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(buildEmptyStats());
@@ -403,7 +398,6 @@
     @Test
     public void testUidStatsAcrossNetworks() throws Exception {
         // pretend first mobile network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -415,7 +409,6 @@
 
         // create some traffic on first network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 2048L, 16L, 512L, 4L));
@@ -437,7 +430,6 @@
         // now switch networks; this also tests that we're okay with interfaces
         // disappearing, to verify we don't count backwards.
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_2));
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
@@ -454,7 +446,6 @@
 
         // create traffic on second network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 2176L, 17L, 1536L, 12L));
@@ -483,7 +474,6 @@
     @Test
     public void testUidRemovedIsMoved() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -495,7 +485,6 @@
 
         // create some traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4128L, 258L, 544L, 34L));
@@ -517,7 +506,6 @@
 
         // now pretend two UIDs are uninstalled, which should migrate stats to
         // special "removed" bucket.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4128L, 258L, 544L, 34L));
@@ -545,7 +533,6 @@
     @Test
     public void testUid3g4gCombinedByTemplate() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -557,7 +544,6 @@
 
         // create some traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -573,7 +559,6 @@
 
         // now switch over to 4g network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile4gState(TEST_IFACE2));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -588,7 +573,6 @@
 
         // create traffic on second network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -607,7 +591,6 @@
     @Test
     public void testSummaryForAllUid() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -619,7 +602,6 @@
 
         // create some traffic for two apps
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -637,7 +619,6 @@
 
         // now create more traffic in next hour, but only for one app
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -669,7 +650,6 @@
     @Test
     public void testForegroundBackground() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -681,7 +661,6 @@
 
         // create some initial traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -697,7 +676,6 @@
 
         // now switch to foreground
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -730,7 +708,6 @@
     @Test
     public void testMetered() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState(true /* isMetered */));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -742,7 +719,6 @@
 
         // create some initial traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         // Note that all traffic from NetworkManagementService is tagged as METERED_NO, ROAMING_NO
@@ -772,7 +748,6 @@
     @Test
     public void testRoaming() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1, true /* isRoaming */));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -784,7 +759,6 @@
 
         // Create some traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         // Note that all traffic from NetworkManagementService is tagged as METERED_NO and
@@ -813,7 +787,6 @@
     @Test
     public void testTethering() throws Exception {
         // pretend first mobile network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -825,7 +798,6 @@
 
         // create some tethering traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
 
         // Traffic seen by kernel counters (includes software tethering).
@@ -858,7 +830,6 @@
     public void testRegisterUsageCallback() throws Exception {
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -880,7 +851,6 @@
         Messenger messenger = new Messenger(latchedHandler);
 
         // Force poll
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(buildEmptyStats());
@@ -909,7 +879,6 @@
         // modify some number on wifi, and trigger poll event
         // not enough traffic to call data usage callback
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 1024L, 1L, 2048L, 2L));
@@ -925,7 +894,6 @@
         // and bump forward again, with counters going higher. this is
         // important, since it will trigger the data usage callback
         incrementCurrentTime(DAY_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4096000L, 4L, 8192000L, 8L));
@@ -1068,7 +1036,6 @@
     private void expectSettings(long persistBytes, long bucketDuration, long deleteAge)
             throws Exception {
         when(mSettings.getPollInterval()).thenReturn(HOUR_IN_MILLIS);
-        when(mSettings.getTimeCacheMaxAge()).thenReturn(DAY_IN_MILLIS);
         when(mSettings.getSampleEnabled()).thenReturn(true);
 
         final Config config = new Config(bucketDuration, deleteAge, deleteAge);
@@ -1084,14 +1051,6 @@
         when(mSettings.getUidTagPersistBytes(anyLong())).thenReturn(MB_IN_BYTES);
     }
 
-    private void expectCurrentTime() throws Exception {
-        when(mTime.forceRefresh()).thenReturn(false);
-        when(mTime.hasCache()).thenReturn(true);
-        when(mTime.currentTimeMillis()).thenReturn(currentTimeMillis());
-        when(mTime.getCacheAge()).thenReturn(0L);
-        when(mTime.getCacheCertainty()).thenReturn(0L);
-    }
-
     private void expectBandwidthControlCheck() throws Exception {
         when(mNetManager.isBandwidthControlEnabled()).thenReturn(true);
     }