Tests for ThrottleService, NTP into TrustedTime.

Wrote initial suite of tests for ThrottleService, checking a variety
of edge cases.  Checks going over limits, updating policies, and reset
after cycle elapses.

Moved NTP code in ThrottleService into new TrustedTime interface,
which makes it easier to understand, and allows tests to provide custom
clocks.

Change-Id: I0d62b8b3a169516a2ab2d33025f6fe30dc792be8

1 files changed, 104 insertions, 79 deletions

diff --git a/services/java/com/android/server/ThrottleService.java b/services/java/com/android/server/ThrottleService.java
index d841cb3a7766..02332b7aa918 100644
--- a/services/java/com/android/server/ThrottleService.java
+++ b/services/java/com/android/server/ThrottleService.java
@@ -16,6 +16,9 @@
 
 package com.android.server;
 
+import com.android.internal.R;
+import com.android.internal.telephony.TelephonyProperties;
+
 import android.app.AlarmManager;
 import android.app.Notification;
 import android.app.NotificationManager;
@@ -30,7 +33,6 @@ import android.content.res.Resources;
 import android.database.ContentObserver;
 import android.net.INetworkManagementEventObserver;
 import android.net.IThrottleManager;
-import android.net.SntpClient;
 import android.net.ThrottleManager;
 import android.os.Binder;
 import android.os.Environment;
@@ -47,10 +49,9 @@ import android.os.SystemProperties;
 import android.provider.Settings;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
+import android.util.NtpTrustedTime;
 import android.util.Slog;
-
-import com.android.internal.R;
-import com.android.internal.telephony.TelephonyProperties;
+import android.util.TrustedTime;
 
 import java.io.BufferedWriter;
 import java.io.File;
@@ -60,11 +61,11 @@ import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.Calendar;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicLong;
 import java.util.GregorianCalendar;
 import java.util.Properties;
 import java.util.Random;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
 
 // TODO - add comments - reference the ThrottleManager for public API
 public class ThrottleService extends IThrottleManager.Stub {
@@ -84,6 +85,11 @@ public class ThrottleService extends IThrottleManager.Stub {
     private static final int TESTING_RESET_PERIOD_SEC = 60 * 10;
     private static final long TESTING_THRESHOLD = 1 * 1024 * 1024;
 
+    private static final long MAX_NTP_CACHE_AGE = 24 * 60 * 60 * 1000;
+    private static final long MAX_NTP_FETCH_WAIT = 20 * 1000;
+
+    private long mMaxNtpCacheAge = MAX_NTP_CACHE_AGE;
+
     private int mPolicyPollPeriodSec;
     private AtomicLong mPolicyThreshold;
     private AtomicInteger mPolicyThrottleValue;
@@ -121,10 +127,24 @@ public class ThrottleService extends IThrottleManager.Stub {
     private static final int THROTTLE_INDEX_UNTHROTTLED   =  0;
 
     private static final String PROPERTIES_FILE = "/etc/gps.conf";
-    private String mNtpServer;
-    private boolean mNtpActive;
+
+    private Intent mPollStickyBroadcast;
+
+    private TrustedTime mTime;
+
+    private static INetworkManagementService getNetworkManagementService() {
+        final IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
+        return INetworkManagementService.Stub.asInterface(b);
+    }
 
     public ThrottleService(Context context) {
+        // TODO: move to using cached NtpTrustedTime
+        this(context, getNetworkManagementService(), new NtpTrustedTime(),
+                context.getResources().getString(R.string.config_datause_iface));
+    }
+
+    public ThrottleService(Context context, INetworkManagementService nmService, TrustedTime time,
+            String iface) {
         if (VDBG) Slog.v(TAG, "Starting ThrottleService");
         mContext = context;
 
@@ -132,17 +152,15 @@ public class ThrottleService extends IThrottleManager.Stub {
         mPolicyThrottleValue = new AtomicInteger();
         mThrottleIndex = new AtomicInteger();
 
-        mNtpActive = false;
-
-        mIface = mContext.getResources().getString(R.string.config_datause_iface);
+        mIface = iface;
         mAlarmManager = (AlarmManager)mContext.getSystemService(Context.ALARM_SERVICE);
         Intent pollIntent = new Intent(ACTION_POLL, null);
         mPendingPollIntent = PendingIntent.getBroadcast(mContext, POLL_REQUEST, pollIntent, 0);
         Intent resetIntent = new Intent(ACTION_RESET, null);
         mPendingResetIntent = PendingIntent.getBroadcast(mContext, RESET_REQUEST, resetIntent, 0);
 
-        IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
-        mNMService = INetworkManagementService.Stub.asInterface(b);
+        mNMService = nmService;
+        mTime = time;
 
         mNotificationManager = (NotificationManager)mContext.getSystemService(
                 Context.NOTIFICATION_SERVICE);
@@ -189,7 +207,7 @@ public class ThrottleService extends IThrottleManager.Stub {
             mMsg = msg;
         }
 
-        void observe(Context context) {
+        void register(Context context) {
             ContentResolver resolver = context.getContentResolver();
             resolver.registerContentObserver(Settings.Secure.getUriFor(
                     Settings.Secure.THROTTLE_POLLING_SEC), false, this);
@@ -207,6 +225,11 @@ public class ThrottleService extends IThrottleManager.Stub {
                     Settings.Secure.THROTTLE_MAX_NTP_CACHE_AGE_SEC), false, this);
         }
 
+        void unregister(Context context) {
+            final ContentResolver resolver = context.getContentResolver();
+            resolver.unregisterContentObserver(this);
+        }
+
         @Override
         public void onChange(boolean selfChange) {
             mHandler.obtainMessage(mMsg).sendToTarget();
@@ -220,7 +243,9 @@ public class ThrottleService extends IThrottleManager.Stub {
     }
 
     private long ntpToWallTime(long ntpTime) {
-        long bestNow = getBestTime(true); // do it quickly
+        // get time quickly without worrying about trusted state
+        long bestNow = mTime.hasCache() ? mTime.currentTimeMillis()
+                : System.currentTimeMillis();
         long localNow = System.currentTimeMillis();
         return localNow + (ntpTime - bestNow);
     }
@@ -300,7 +325,7 @@ public class ThrottleService extends IThrottleManager.Stub {
             new BroadcastReceiver() {
                 @Override
                 public void onReceive(Context context, Intent intent) {
-                    mHandler.obtainMessage(EVENT_POLL_ALARM).sendToTarget();
+                    dispatchPoll();
                 }
             }, new IntentFilter(ACTION_POLL));
 
@@ -308,7 +333,7 @@ public class ThrottleService extends IThrottleManager.Stub {
             new BroadcastReceiver() {
                 @Override
                 public void onReceive(Context context, Intent intent) {
-                    mHandler.obtainMessage(EVENT_RESET_ALARM).sendToTarget();
+                    dispatchReset();
                 }
             }, new IntentFilter(ACTION_RESET));
 
@@ -318,7 +343,10 @@ public class ThrottleService extends IThrottleManager.Stub {
             File file = new File(PROPERTIES_FILE);
             stream = new FileInputStream(file);
             properties.load(stream);
-            mNtpServer = properties.getProperty("NTP_SERVER", null);
+            final String ntpServer = properties.getProperty("NTP_SERVER", null);
+            if (mTime instanceof NtpTrustedTime) {
+                ((NtpTrustedTime) mTime).setNtpServer(ntpServer, MAX_NTP_FETCH_WAIT);
+            }
         } catch (IOException e) {
             Slog.e(TAG, "Could not open GPS configuration file " + PROPERTIES_FILE);
         } finally {
@@ -343,9 +371,33 @@ public class ThrottleService extends IThrottleManager.Stub {
         }
 
         mSettingsObserver = new SettingsObserver(mHandler, EVENT_POLICY_CHANGED);
-        mSettingsObserver.observe(mContext);
+        mSettingsObserver.register(mContext);
+    }
+
+    void shutdown() {
+        // TODO: eventually connect with ShutdownThread to persist stats during
+        // graceful shutdown.
+
+        if (mThread != null) {
+            mThread.quit();
+        }
+
+        if (mSettingsObserver != null) {
+            mSettingsObserver.unregister(mContext);
+        }
+
+        if (mPollStickyBroadcast != null) {
+            mContext.removeStickyBroadcast(mPollStickyBroadcast);
+        }
     }
 
+    void dispatchPoll() {
+        mHandler.obtainMessage(EVENT_POLL_ALARM).sendToTarget();
+    }
+
+    void dispatchReset() {
+        mHandler.obtainMessage(EVENT_RESET_ALARM).sendToTarget();
+    }
 
     private static final int EVENT_REBOOT_RECOVERY = 0;
     private static final int EVENT_POLICY_CHANGED  = 1;
@@ -440,15 +492,17 @@ public class ThrottleService extends IThrottleManager.Stub {
             mPolicyNotificationsAllowedMask = Settings.Secure.getInt(mContext.getContentResolver(),
                     Settings.Secure.THROTTLE_NOTIFICATION_TYPE, defaultNotificationType);
 
-            mMaxNtpCacheAgeSec = Settings.Secure.getInt(mContext.getContentResolver(),
-                    Settings.Secure.THROTTLE_MAX_NTP_CACHE_AGE_SEC, MAX_NTP_CACHE_AGE_SEC);
+            final int maxNtpCacheAgeSec = Settings.Secure.getInt(mContext.getContentResolver(),
+                    Settings.Secure.THROTTLE_MAX_NTP_CACHE_AGE_SEC,
+                    (int) (MAX_NTP_CACHE_AGE / 1000));
+            mMaxNtpCacheAge = maxNtpCacheAgeSec * 1000;
 
             if (VDBG || (mPolicyThreshold.get() != 0)) {
                 Slog.d(TAG, "onPolicyChanged testing=" + testing +", period=" +
                         mPolicyPollPeriodSec + ", threshold=" + mPolicyThreshold.get() +
                         ", value=" + mPolicyThrottleValue.get() + ", resetDay=" + mPolicyResetDay +
-                        ", noteType=" + mPolicyNotificationsAllowedMask + ", maxNtpCacheAge=" +
-                        mMaxNtpCacheAgeSec);
+                        ", noteType=" + mPolicyNotificationsAllowedMask + ", mMaxNtpCacheAge=" +
+                        mMaxNtpCacheAge);
             }
 
             // force updates
@@ -464,9 +518,15 @@ public class ThrottleService extends IThrottleManager.Stub {
 
         private void onPollAlarm() {
             long now = SystemClock.elapsedRealtime();
-            long next = now + mPolicyPollPeriodSec*1000;
+            long next = now + mPolicyPollPeriodSec * 1000;
 
-            checkForAuthoritativeTime();
+            // when trusted cache outdated, try refreshing
+            if (mTime.getCacheAge() > mMaxNtpCacheAge) {
+                if (mTime.forceRefresh()) {
+                    if (VDBG) Slog.d(TAG, "updated trusted time, reseting alarm");
+                    dispatchReset();
+                }
+            }
 
             long incRead = 0;
             long incWrite = 0;
@@ -509,6 +569,7 @@ public class ThrottleService extends IThrottleManager.Stub {
             broadcast.putExtra(ThrottleManager.EXTRA_CYCLE_START, getPeriodStartTime(mIface));
             broadcast.putExtra(ThrottleManager.EXTRA_CYCLE_END, getResetTime(mIface));
             mContext.sendStickyBroadcast(broadcast);
+            mPollStickyBroadcast = broadcast;
 
             mAlarmManager.cancel(mPendingPollIntent);
             mAlarmManager.set(AlarmManager.ELAPSED_REALTIME, next, mPendingPollIntent);
@@ -538,7 +599,8 @@ public class ThrottleService extends IThrottleManager.Stub {
 
             // have we spoken with an ntp server yet?
             // this is controversial, but we'd rather err towards not throttling
-            if ((mNtpServer != null) && !mNtpActive) {
+            if (!mTime.hasCache()) {
+                Slog.w(TAG, "missing trusted time, skipping throttle check");
                 return;
             }
 
@@ -697,9 +759,15 @@ public class ThrottleService extends IThrottleManager.Stub {
                         " bytes read and " + mRecorder.getPeriodTx(0) + " written");
             }
 
-            long now = getBestTime(false);
+            // when trusted cache outdated, try refreshing
+            if (mTime.getCacheAge() > mMaxNtpCacheAge) {
+                mTime.forceRefresh();
+            }
 
-            if (mNtpActive || (mNtpServer == null)) {
+            // as long as we have a trusted time cache, we always reset alarms,
+            // even if the refresh above failed.
+            if (mTime.hasCache()) {
+                final long now = mTime.currentTimeMillis();
                 Calendar end = calculatePeriodEnd(now);
                 Calendar start = calculatePeriodStart(end);
 
@@ -714,56 +782,11 @@ public class ThrottleService extends IThrottleManager.Stub {
                         SystemClock.elapsedRealtime() + offset,
                         mPendingResetIntent);
             } else {
-                if (VDBG) Slog.d(TAG, "no authoritative time - not resetting period");
+                if (VDBG) Slog.d(TAG, "no trusted time, not resetting period");
             }
         }
     }
 
-    private void checkForAuthoritativeTime() {
-        if (mNtpActive || (mNtpServer == null)) return;
-
-        // will try to get the ntp time and switch to it if found.
-        // will also cache the time so we don't fetch it repeatedly.
-        getBestTime(false);
-    }
-
-    private static final int MAX_NTP_CACHE_AGE_SEC = 60 * 60 * 24; // 1 day
-    private static final int MAX_NTP_FETCH_WAIT = 20 * 1000;
-    private int mMaxNtpCacheAgeSec = MAX_NTP_CACHE_AGE_SEC;
-    private long cachedNtp;
-    private long cachedNtpTimestamp;
-
-    // if the request is tied to UI and ANR's are a danger, request a fast result
-    // the regular polling should have updated the cached time recently using the
-    // slower method (!fast)
-    private long getBestTime(boolean fast) {
-        if (mNtpServer != null) {
-            if (mNtpActive) {
-                long ntpAge = SystemClock.elapsedRealtime() - cachedNtpTimestamp;
-                if (ntpAge < mMaxNtpCacheAgeSec * 1000 || fast) {
-                    if (VDBG) Slog.v(TAG, "using cached time");
-                    return cachedNtp + ntpAge;
-                }
-            }
-            SntpClient client = new SntpClient();
-            if (client.requestTime(mNtpServer, MAX_NTP_FETCH_WAIT)) {
-                cachedNtp = client.getNtpTime();
-                cachedNtpTimestamp = SystemClock.elapsedRealtime();
-                if (!mNtpActive) {
-                    mNtpActive = true;
-                    if (VDBG) Slog.d(TAG, "found Authoritative time - reseting alarm");
-                    mHandler.obtainMessage(EVENT_RESET_ALARM).sendToTarget();
-                }
-                if (VDBG) Slog.v(TAG, "using Authoritative time: " + cachedNtp);
-                return cachedNtp;
-            }
-        }
-        long time = System.currentTimeMillis();
-        if (VDBG) Slog.v(TAG, "using User time: " + time);
-        mNtpActive = false;
-        return time;
-    }
-
     // records bytecount data for a given time and accumulates it into larger time windows
     // for logging and other purposes
     //
@@ -929,7 +952,7 @@ public class ThrottleService extends IThrottleManager.Stub {
         private void checkAndDeleteLRUDataFile(File dir) {
             File[] files = dir.listFiles();
 
-            if (files.length <= MAX_SIMS_SUPPORTED) return;
+            if (files == null || files.length <= MAX_SIMS_SUPPORTED) return;
             if (DBG) Slog.d(TAG, "Too many data files");
             do {
                 File oldest = null;
@@ -949,9 +972,11 @@ public class ThrottleService extends IThrottleManager.Stub {
             File newest = null;
             File[] files = dir.listFiles();
 
-            for (File f : files) {
-                if ((newest == null) || (newest.lastModified() < f.lastModified())) {
-                    newest = f;
+            if (files != null) {
+                for (File f : files) {
+                    if ((newest == null) || (newest.lastModified() < f.lastModified())) {
+                        newest = f;
+                    }
                 }
             }
             if (newest == null) {
@@ -1126,7 +1151,7 @@ public class ThrottleService extends IThrottleManager.Stub {
                 " seconds.");
         pw.println("Polling every " + mPolicyPollPeriodSec + " seconds");
         pw.println("Current Throttle Index is " + mThrottleIndex.get());
-        pw.println("Max NTP Cache Age is " + mMaxNtpCacheAgeSec);
+        pw.println("mMaxNtpCacheAge=" + mMaxNtpCacheAge);
 
         for (int i = 0; i < mRecorder.getPeriodCount(); i++) {
             pw.println(" Period[" + i + "] - read:" + mRecorder.getPeriodRx(i) + ", written:" +