Add NtpTimeHelper (a1862b58) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/location/ExponentialBackOff.java

0 → 100644

+32 −0

Original line number	Diff line number	Diff line
		package com.android.server.location;

		/**
		* A simple implementation of exponential backoff.
		*/
		class ExponentialBackOff {
		private static final int MULTIPLIER = 2;
		private final long mInitIntervalMillis;
		private final long mMaxIntervalMillis;
		private long mCurrentIntervalMillis;

		ExponentialBackOff(long initIntervalMillis, long maxIntervalMillis) {
		mInitIntervalMillis = initIntervalMillis;
		mMaxIntervalMillis = maxIntervalMillis;

		mCurrentIntervalMillis = mInitIntervalMillis / MULTIPLIER;
		}

		long nextBackoffMillis() {
		if (mCurrentIntervalMillis > mMaxIntervalMillis) {
		return mMaxIntervalMillis;
		}

		mCurrentIntervalMillis *= MULTIPLIER;
		return mCurrentIntervalMillis;
		}

		void reset() {
		mCurrentIntervalMillis = mInitIntervalMillis / MULTIPLIER;
		}
		}

services/core/java/com/android/server/location/GnssLocationProvider.java

+22 −129

Original line number	Diff line number	Diff line
		@@ -76,14 +76,14 @@ import android.telephony.TelephonyManager;
		import android.telephony.gsm.GsmCellLocation;
		import android.text.TextUtils;
		import android.util.Log;
		import android.util.NtpTrustedTime;
		import com.android.internal.app.IAppOpsService;

		import com.android.internal.app.IBatteryStats;
		import com.android.internal.location.GpsNetInitiatedHandler;
		import com.android.internal.location.GpsNetInitiatedHandler.GpsNiNotification;
		import com.android.internal.location.ProviderProperties;
		import com.android.internal.location.ProviderRequest;
		import com.android.internal.location.gnssmetrics.GnssMetrics;
		import com.android.server.location.NtpTimeHelper.InjectNtpTimeCallback;
		import java.io.File;
		import java.io.FileDescriptor;
		import java.io.FileInputStream;
		@@ -93,7 +93,6 @@ import java.net.InetAddress;
		import java.net.UnknownHostException;
		import java.util.ArrayList;
		import java.util.Arrays;
		import java.util.Date;
		import java.util.HashMap;
		import java.util.List;
		import java.util.Map;
		@@ -107,7 +106,7 @@ import libcore.io.IoUtils;
		*
		* {@hide}
		*/
		public class GnssLocationProvider implements LocationProviderInterface {
		public class GnssLocationProvider implements LocationProviderInterface, InjectNtpTimeCallback {

		private static final String TAG = "GnssLocationProvider";

		@@ -208,7 +207,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		private static final int UPDATE_LOCATION = 7; // Handle external location from network listener
		private static final int ADD_LISTENER = 8;
		private static final int REMOVE_LISTENER = 9;
		private static final int INJECT_NTP_TIME_FINISHED = 10;
		private static final int DOWNLOAD_XTRA_DATA_FINISHED = 11;
		private static final int SUBSCRIPTION_OR_SIM_CHANGED = 12;
		private static final int INITIALIZE_HANDLER = 13;
		@@ -329,9 +327,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		// Typical hot TTTF is ~5 seconds, so 10 seconds seems sane.
		private static final int GPS_POLLING_THRESHOLD_INTERVAL = 10 * 1000;

		// how often to request NTP time, in milliseconds
		// current setting 24 hours
		private static final long NTP_INTERVAL = 24 * 60 * 60 * 1000;
		// how long to wait if we have a network error in NTP or XTRA downloading
		// the initial value of the exponential backoff
		// current setting - 5 minutes
		@@ -344,8 +339,8 @@ public class GnssLocationProvider implements LocationProviderInterface {
		// Timeout when holding wakelocks for downloading XTRA data.
		private static final long DOWNLOAD_XTRA_DATA_TIMEOUT_MS = 60 * 1000;

		private BackOff mNtpBackOff = new BackOff(RETRY_INTERVAL, MAX_RETRY_INTERVAL);
		private BackOff mXtraBackOff = new BackOff(RETRY_INTERVAL, MAX_RETRY_INTERVAL);
		private final ExponentialBackOff mXtraBackOff = new ExponentialBackOff(RETRY_INTERVAL,
		MAX_RETRY_INTERVAL);

		// true if we are enabled, protected by this
		private boolean mEnabled;
		@@ -357,12 +352,8 @@ public class GnssLocationProvider implements LocationProviderInterface {

		// flags to trigger NTP or XTRA data download when network becomes available
		// initialized to true so we do NTP and XTRA when the network comes up after booting
		private int mInjectNtpTimePending = STATE_PENDING_NETWORK;
		private int mDownloadXtraDataPending = STATE_PENDING_NETWORK;

		// set to true if the GPS engine requested on-demand NTP time requests
		private boolean mOnDemandTimeInjection;

		// true if GPS is navigating
		private boolean mNavigating;

		@@ -417,7 +408,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		private boolean mSuplEsEnabled = false;

		private final Context mContext;
		private final NtpTrustedTime mNtpTime;
		private final ILocationManager mILocationManager;
		private final LocationExtras mLocationExtras = new LocationExtras();
		private final GnssStatusListenerHelper mListenerHelper;
		@@ -425,6 +415,7 @@ public class GnssLocationProvider implements LocationProviderInterface {
		private final GnssNavigationMessageProvider mGnssNavigationMessageProvider;
		private final LocationChangeListener mNetworkLocationListener = new NetworkLocationListener();
		private final LocationChangeListener mFusedLocationListener = new FusedLocationListener();
		private final NtpTimeHelper mNtpTimeHelper;

		// Handler for processing events
		private Handler mHandler;
		@@ -517,9 +508,7 @@ public class GnssLocationProvider implements LocationProviderInterface {
		new ConnectivityManager.NetworkCallback() {
		@Override
		public void onAvailable(Network network) {
		if (mInjectNtpTimePending == STATE_PENDING_NETWORK) {
		requestUtcTime();
		}
		mNtpTimeHelper.onNetworkAvailable();
		if (mDownloadXtraDataPending == STATE_PENDING_NETWORK) {
		if (mSupportsXtra) {
		// Download only if supported, (prevents an unneccesary on-boot
		@@ -762,7 +751,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		public GnssLocationProvider(Context context, ILocationManager ilocationManager,
		Looper looper) {
		mContext = context;
		mNtpTime = NtpTrustedTime.getInstance(context);
		mILocationManager = ilocationManager;

		// Create a wake lock
		@@ -880,6 +868,8 @@ public class GnssLocationProvider implements LocationProviderInterface {
		}
		};
		mGnssMetrics = new GnssMetrics(mBatteryStats);

		mNtpTimeHelper = new NtpTimeHelper(mContext, Looper.myLooper(), this);
		}

		/**
		@@ -895,6 +885,15 @@ public class GnssLocationProvider implements LocationProviderInterface {
		return PROPERTIES;
		}


		/**
		* Implements {@link InjectNtpTimeCallback#injectTime}
		*/
		@Override
		public void injectTime(long time, long timeReference, int uncertainty) {
		native_inject_time(time, timeReference, uncertainty);
		}

		private void handleUpdateNetworkState(Network network) {
		// retrieve NetworkInfo for this UID
		NetworkInfo info = mConnMgr.getNetworkInfo(network);
		@@ -1015,78 +1014,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		}
		}

		private void handleInjectNtpTime() {
		if (mInjectNtpTimePending == STATE_DOWNLOADING) {
		// already downloading data
		return;
		}
		if (!isDataNetworkConnected()) {
		// try again when network is up
		mInjectNtpTimePending = STATE_PENDING_NETWORK;
		return;
		}
		mInjectNtpTimePending = STATE_DOWNLOADING;

		// hold wake lock while task runs
		mWakeLock.acquire();
		Log.i(TAG, "WakeLock acquired by handleInjectNtpTime()");
		AsyncTask.THREAD_POOL_EXECUTOR.execute(new Runnable() {
		@Override
		public void run() {
		long delay;

		// force refresh NTP cache when outdated
		boolean refreshSuccess = true;
		if (mNtpTime.getCacheAge() >= NTP_INTERVAL) {
		refreshSuccess = mNtpTime.forceRefresh();
		}

		// only update when NTP time is fresh
		if (mNtpTime.getCacheAge() < NTP_INTERVAL) {
		long time = mNtpTime.getCachedNtpTime();
		long timeReference = mNtpTime.getCachedNtpTimeReference();
		long certainty = mNtpTime.getCacheCertainty();

		if (DEBUG) {
		long now = System.currentTimeMillis();
		Log.d(TAG, "NTP server returned: "
		+ time + " (" + new Date(time)
		+ ") reference: " + timeReference
		+ " certainty: " + certainty
		+ " system time offset: " + (time - now));
		}

		native_inject_time(time, timeReference, (int) certainty);
		delay = NTP_INTERVAL;
		mNtpBackOff.reset();
		} else {
		Log.e(TAG, "requestTime failed");
		delay = mNtpBackOff.nextBackoffMillis();
		}

		sendMessage(INJECT_NTP_TIME_FINISHED, 0, null);

		if (DEBUG) {
		String message = String.format(
		"onDemandTimeInjection=%s, refreshSuccess=%s, delay=%s",
		mOnDemandTimeInjection,
		refreshSuccess,
		delay);
		Log.d(TAG, message);
		}
		if (mOnDemandTimeInjection \|\| !refreshSuccess) {
		// send delayed message for next NTP injection
		// since this is delayed and not urgent we do not hold a wake lock here
		mHandler.sendEmptyMessageDelayed(INJECT_NTP_TIME, delay);
		}

		// release wake lock held by task
		mWakeLock.release();
		Log.i(TAG, "WakeLock released by handleInjectNtpTime()");
		}
		});
		}

		private void handleRequestLocation(boolean independentFromGnss) {
		if (isRequestLocationRateLimited()) {
		if (DEBUG) {
		@@ -2006,7 +1933,7 @@ public class GnssLocationProvider implements LocationProviderInterface {
		mEngineCapabilities = capabilities;

		if (hasCapability(GPS_CAPABILITY_ON_DEMAND_TIME)) {
		mOnDemandTimeInjection = true;
		mNtpTimeHelper.enablePeriodicTimeInjection();
		requestUtcTime();
		}

		@@ -2467,7 +2394,7 @@ public class GnssLocationProvider implements LocationProviderInterface {
		handleReleaseSuplConnection(msg.arg1);
		break;
		case INJECT_NTP_TIME:
		handleInjectNtpTime();
		mNtpTimeHelper.retrieveAndInjectNtpTime();
		break;
		case REQUEST_LOCATION:
		handleRequestLocation((boolean) msg.obj);
		@@ -2475,9 +2402,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		case DOWNLOAD_XTRA_DATA:
		handleDownloadXtraData();
		break;
		case INJECT_NTP_TIME_FINISHED:
		mInjectNtpTimePending = STATE_IDLE;
		break;
		case DOWNLOAD_XTRA_DATA_FINISHED:
		mDownloadXtraDataPending = STATE_IDLE;
		break;
		@@ -2808,8 +2732,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		return "REQUEST_LOCATION";
		case DOWNLOAD_XTRA_DATA:
		return "DOWNLOAD_XTRA_DATA";
		case INJECT_NTP_TIME_FINISHED:
		return "INJECT_NTP_TIME_FINISHED";
		case DOWNLOAD_XTRA_DATA_FINISHED:
		return "DOWNLOAD_XTRA_DATA_FINISHED";
		case UPDATE_LOCATION:
		@@ -2856,36 +2778,6 @@ public class GnssLocationProvider implements LocationProviderInterface {
		pw.append(s);
		}

		/**
		* A simple implementation of exponential backoff.
		*/
		private static final class BackOff {
		private static final int MULTIPLIER = 2;
		private final long mInitIntervalMillis;
		private final long mMaxIntervalMillis;
		private long mCurrentIntervalMillis;

		public BackOff(long initIntervalMillis, long maxIntervalMillis) {
		mInitIntervalMillis = initIntervalMillis;
		mMaxIntervalMillis = maxIntervalMillis;

		mCurrentIntervalMillis = mInitIntervalMillis / MULTIPLIER;
		}

		public long nextBackoffMillis() {
		if (mCurrentIntervalMillis > mMaxIntervalMillis) {
		return mMaxIntervalMillis;
		}

		mCurrentIntervalMillis *= MULTIPLIER;
		return mCurrentIntervalMillis;
		}

		public void reset() {
		mCurrentIntervalMillis = mInitIntervalMillis / MULTIPLIER;
		}
		}

		// preallocated to avoid memory allocation in reportNmea()
		private byte[] mNmeaBuffer = new byte[120];

		@@ -3022,3 +2914,4 @@ public class GnssLocationProvider implements LocationProviderInterface {
		private static native void native_cleanup_batching();

		}

services/core/java/com/android/server/location/NtpTimeHelper.java

0 → 100644

+191 −0

Original line number	Diff line number	Diff line
		package com.android.server.location;

		import android.content.Context;
		import android.net.ConnectivityManager;
		import android.net.NetworkInfo;
		import android.os.Handler;
		import android.os.Looper;
		import android.os.PowerManager;
		import android.os.PowerManager.WakeLock;
		import android.util.Log;
		import android.util.NtpTrustedTime;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;

		import java.util.Date;

		/**
		* Handles inject NTP time to GNSS.
		*
		* <p>The client is responsible to call {@link #onNetworkAvailable()} when network is available
		* for retrieving NTP Time.
		*/
		class NtpTimeHelper {

		private static final String TAG = "NtpTimeHelper";
		private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);

		// states for injecting ntp
		private static final int STATE_PENDING_NETWORK = 0;
		private static final int STATE_RETRIEVING_AND_INJECTING = 1;
		private static final int STATE_IDLE = 2;

		// how often to request NTP time, in milliseconds
		// current setting 24 hours
		@VisibleForTesting
		static final long NTP_INTERVAL = 24 * 60 * 60 * 1000;

		// how long to wait if we have a network error in NTP
		// the initial value of the exponential backoff
		// current setting - 5 minutes
		@VisibleForTesting
		static final long RETRY_INTERVAL = 5 * 60 * 1000;
		// how long to wait if we have a network error in NTP
		// the max value of the exponential backoff
		// current setting - 4 hours
		private static final long MAX_RETRY_INTERVAL = 4 * 60 * 60 * 1000;

		private static final long WAKELOCK_TIMEOUT_MILLIS = 60 * 1000;
		private static final String WAKELOCK_KEY = "NtpTimeHelper";

		private final ExponentialBackOff mNtpBackOff = new ExponentialBackOff(RETRY_INTERVAL,
		MAX_RETRY_INTERVAL);

		private final ConnectivityManager mConnMgr;
		private final NtpTrustedTime mNtpTime;
		private final WakeLock mWakeLock;
		private final Handler mHandler;

		@GuardedBy("this")
		private final InjectNtpTimeCallback mCallback;

		// flags to trigger NTP when network becomes available
		// initialized to STATE_PENDING_NETWORK so we do NTP when the network comes up after booting
		@GuardedBy("this")
		private int mInjectNtpTimeState = STATE_PENDING_NETWORK;

		// set to true if the GPS engine requested on-demand NTP time requests
		@GuardedBy("this")
		private boolean mOnDemandTimeInjection;

		interface InjectNtpTimeCallback {
		void injectTime(long time, long timeReference, int uncertainty);
		}

		@VisibleForTesting
		NtpTimeHelper(Context context, Looper looper, InjectNtpTimeCallback callback,
		NtpTrustedTime ntpTime) {
		mConnMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
		mCallback = callback;
		mNtpTime = ntpTime;
		mHandler = new Handler(looper);
		PowerManager powerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
		mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKELOCK_KEY);
		}

		NtpTimeHelper(Context context, Looper looper, InjectNtpTimeCallback callback) {
		this(context, looper, callback, NtpTrustedTime.getInstance(context));
		}

		synchronized void enablePeriodicTimeInjection() {
		mOnDemandTimeInjection = true;
		}

		synchronized void onNetworkAvailable() {
		if (mInjectNtpTimeState == STATE_PENDING_NETWORK) {
		retrieveAndInjectNtpTime();
		}
		}

		/**
		* @return {@code true} if there is a network available for outgoing connections,
		* {@code false} otherwise.
		*/
		private boolean isNetworkConnected() {
		NetworkInfo activeNetworkInfo = mConnMgr.getActiveNetworkInfo();
		return activeNetworkInfo != null && activeNetworkInfo.isConnected();
		}

		synchronized void retrieveAndInjectNtpTime() {
		if (mInjectNtpTimeState == STATE_RETRIEVING_AND_INJECTING) {
		// already downloading data
		return;
		}
		if (!isNetworkConnected()) {
		// try again when network is up
		mInjectNtpTimeState = STATE_PENDING_NETWORK;
		return;
		}
		mInjectNtpTimeState = STATE_RETRIEVING_AND_INJECTING;

		// hold wake lock while task runs
		mWakeLock.acquire(WAKELOCK_TIMEOUT_MILLIS);
		new Thread(this::blockingGetNtpTimeAndInject).start();
		}

		/** {@link NtpTrustedTime#forceRefresh} is a blocking network operation. */
		private void blockingGetNtpTimeAndInject() {
		long delay;

		// force refresh NTP cache when outdated
		boolean refreshSuccess = true;
		if (mNtpTime.getCacheAge() >= NTP_INTERVAL) {
		// Blocking network operation.
		refreshSuccess = mNtpTime.forceRefresh();
		}

		synchronized (this) {
		mInjectNtpTimeState = STATE_IDLE;

		// only update when NTP time is fresh
		// If refreshSuccess is false, cacheAge does not drop down.
		if (mNtpTime.getCacheAge() < NTP_INTERVAL) {
		long time = mNtpTime.getCachedNtpTime();
		long timeReference = mNtpTime.getCachedNtpTimeReference();
		long certainty = mNtpTime.getCacheCertainty();

		if (DEBUG) {
		long now = System.currentTimeMillis();
		Log.d(TAG, "NTP server returned: "
		+ time + " (" + new Date(time)
		+ ") reference: " + timeReference
		+ " certainty: " + certainty
		+ " system time offset: " + (time - now));
		}

		// Ok to cast to int, as can't rollover in practice
		mHandler.post(() -> mCallback.injectTime(time, timeReference, (int) certainty));

		delay = NTP_INTERVAL;
		mNtpBackOff.reset();
		} else {
		Log.e(TAG, "requestTime failed");
		delay = mNtpBackOff.nextBackoffMillis();
		}

		if (DEBUG) {
		Log.d(TAG, String.format(
		"onDemandTimeInjection=%s, refreshSuccess=%s, delay=%s",
		mOnDemandTimeInjection,
		refreshSuccess,
		delay));
		}
		// TODO(b/73893222): reconcile Capabilities bit 'on demand' name vs. de facto periodic
		// injection.
		if (mOnDemandTimeInjection \|\| !refreshSuccess) {
		/* Schedule next NTP injection.
		* Since this is delayed, the wake lock is released right away, and will be held
		* again when the delayed task runs.
		*/
		mHandler.postDelayed(this::retrieveAndInjectNtpTime, delay);
		}
		}
		try {
		// release wake lock held by task
		mWakeLock.release();
		} catch (Exception e) {
		// This happens when the WakeLock is already released.
		}
		}
		}

services/robotests/src/com/android/server/location/NtpTimeHelperTest.java

0 → 100644

+100 −0

Original line number	Diff line number	Diff line
		package com.android.server.location;

		import static com.google.common.truth.Truth.assertThat;

		import static org.mockito.Mockito.doReturn;

		import android.os.Looper;
		import android.platform.test.annotations.Presubmit;
		import android.util.NtpTrustedTime;

		import com.android.server.location.NtpTimeHelper.InjectNtpTimeCallback;
		import com.android.server.testing.FrameworkRobolectricTestRunner;
		import com.android.server.testing.SystemLoaderPackages;

		import org.junit.Before;
		import org.junit.Test;
		import org.junit.runner.RunWith;
		import org.mockito.Mock;
		import org.mockito.MockitoAnnotations;
		import org.robolectric.RuntimeEnvironment;
		import org.robolectric.annotation.Config;
		import org.robolectric.shadows.ShadowLooper;
		import org.robolectric.shadows.ShadowSystemClock;

		import java.util.concurrent.CountDownLatch;
		import java.util.concurrent.TimeUnit;

		/**
		* Unit tests for {@link NtpTimeHelper}.
		*/
		@RunWith(FrameworkRobolectricTestRunner.class)
		@Config(
		manifest = Config.NONE,
		sdk = 27
		)
		@SystemLoaderPackages({"com.android.server.location"})
		@Presubmit
		public class NtpTimeHelperTest {

		private static final long MOCK_NTP_TIME = 1519930775453L;
		@Mock
		private NtpTrustedTime mMockNtpTrustedTime;
		private NtpTimeHelper mNtpTimeHelper;
		private CountDownLatch mCountDownLatch;

		@Before
		public void setUp() throws Exception {
		MockitoAnnotations.initMocks(this);
		mCountDownLatch = new CountDownLatch(1);
		InjectNtpTimeCallback callback =
		(time, timeReference, uncertainty) -> {
		assertThat(time).isEqualTo(MOCK_NTP_TIME);
		mCountDownLatch.countDown();
		};
		mNtpTimeHelper = new NtpTimeHelper(RuntimeEnvironment.application,
		Looper.myLooper(),
		callback, mMockNtpTrustedTime);
		}

		@Test
		public void handleInjectNtpTime_cachedAgeLow_injectTime() throws InterruptedException {
		doReturn(NtpTimeHelper.NTP_INTERVAL - 1).when(mMockNtpTrustedTime).getCacheAge();
		doReturn(MOCK_NTP_TIME).when(mMockNtpTrustedTime).getCachedNtpTime();

		mNtpTimeHelper.retrieveAndInjectNtpTime();

		waitForTasksToBePostedOnHandlerAndRunThem();
		assertThat(mCountDownLatch.await(2, TimeUnit.SECONDS)).isTrue();
		}

		@Test
		public void handleInjectNtpTime_injectTimeFailed_injectTimeDelayed()
		throws InterruptedException {
		doReturn(NtpTimeHelper.NTP_INTERVAL + 1).when(mMockNtpTrustedTime).getCacheAge();
		doReturn(false).when(mMockNtpTrustedTime).forceRefresh();

		mNtpTimeHelper.retrieveAndInjectNtpTime();
		waitForTasksToBePostedOnHandlerAndRunThem();
		assertThat(mCountDownLatch.await(2, TimeUnit.SECONDS)).isFalse();

		doReturn(true).when(mMockNtpTrustedTime).forceRefresh();
		doReturn(1L).when(mMockNtpTrustedTime).getCacheAge();
		doReturn(MOCK_NTP_TIME).when(mMockNtpTrustedTime).getCachedNtpTime();
		ShadowSystemClock.sleep(NtpTimeHelper.RETRY_INTERVAL);

		waitForTasksToBePostedOnHandlerAndRunThem();
		assertThat(mCountDownLatch.await(2, TimeUnit.SECONDS)).isTrue();
		}

		/**
		* Since a thread is created in {@link NtpTimeHelper#retrieveAndInjectNtpTime} and the task to
		* be verified is posted in the thread, we have to wait for the task to be posted and then it
		* can be run.
		*/
		private void waitForTasksToBePostedOnHandlerAndRunThem() throws InterruptedException {
		mCountDownLatch.await(1, TimeUnit.SECONDS);
		ShadowLooper.runUiThreadTasks();
		}
		}