Merge "Extract an interface for ServiceConfigAccessor" (7cf860e1) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/timedetector/ServiceConfigAccessor.java

+25 −188

Original line number	Diff line number	Diff line
		@@ -15,214 +15,51 @@
		*/
		package com.android.server.timedetector;

		import static com.android.server.timedetector.ServerFlags.KEY_TIME_DETECTOR_LOWER_BOUND_MILLIS_OVERRIDE;
		import static com.android.server.timedetector.ServerFlags.KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE;
		import static com.android.server.timedetector.TimeDetectorStrategy.ORIGIN_NETWORK;
		import static com.android.server.timedetector.TimeDetectorStrategy.ORIGIN_TELEPHONY;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.content.Context;
		import android.os.Build;
		import android.os.SystemProperties;

		import com.android.internal.R;
		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.util.Preconditions;
		import com.android.server.timedetector.TimeDetectorStrategy.Origin;
		import com.android.server.timezonedetector.ConfigurationChangeListener;

		import java.time.Instant;
		import java.util.Arrays;
		import java.util.Objects;
		import java.util.Optional;
		import java.util.Set;
		import java.util.function.Supplier;

		/**
		* A singleton that provides access to service configuration for time detection. This hides how
		* configuration is split between static, compile-time config and dynamic, server-pushed flags. It
		* provides a rudimentary mechanism to signal when values have changed.
		*/
		final class ServiceConfigAccessor {

		private static final int SYSTEM_CLOCK_UPDATE_THRESHOLD_MILLIS_DEFAULT = 2 * 1000;

		/**
		* By default telephony and network only suggestions are accepted and telephony takes
		* precedence over network.
		*/
		private static final @Origin int[]
		DEFAULT_AUTOMATIC_TIME_ORIGIN_PRIORITIES = { ORIGIN_TELEPHONY, ORIGIN_NETWORK };

		/**
		* Time in the past. If an automatic time suggestion is before this point, it is sure to be
		* incorrect.
		*/
		private static final Instant TIME_LOWER_BOUND_DEFAULT = Instant.ofEpochMilli(
		Long.max(android.os.Environment.getRootDirectory().lastModified(), Build.TIME));

		/** Device config keys that affect the {@link TimeDetectorService}. */
		private static final Set<String> SERVER_FLAGS_KEYS_TO_WATCH = Set.of(
		KEY_TIME_DETECTOR_LOWER_BOUND_MILLIS_OVERRIDE,
		KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE
		);

		private static final Object SLOCK = new Object();

		/** The singleton instance. Initialized once in {@link #getInstance(Context)}. */
		@GuardedBy("SLOCK")
		@Nullable
		private static ServiceConfigAccessor sInstance;

		@NonNull private final Context mContext;
		@NonNull private final ConfigOriginPrioritiesSupplier mConfigOriginPrioritiesSupplier;
		@NonNull private final ServerFlagsOriginPrioritiesSupplier mServerFlagsOriginPrioritiesSupplier;
		@NonNull private final ServerFlags mServerFlags;

		/**
		* If a newly calculated system clock time and the current system clock time differs by this or
		* more the system clock will actually be updated. Used to prevent the system clock being set
		* for only minor differences.
		* An interface that provides access to service configuration for time detection. This hides
		* how configuration is split between static, compile-time config, dynamic server-pushed flags and
		* user settings. It provides listeners to signal when values that affect different components have
		* changed.
		*/
		private final int mSystemClockUpdateThresholdMillis;

		private ServiceConfigAccessor(@NonNull Context context) {
		mContext = Objects.requireNonNull(context);
		mServerFlags = ServerFlags.getInstance(mContext);
		mConfigOriginPrioritiesSupplier = new ConfigOriginPrioritiesSupplier(context);
		mServerFlagsOriginPrioritiesSupplier =
		new ServerFlagsOriginPrioritiesSupplier(mServerFlags);
		mSystemClockUpdateThresholdMillis =
		SystemProperties.getInt("ro.sys.time_detector_update_diff",
		SYSTEM_CLOCK_UPDATE_THRESHOLD_MILLIS_DEFAULT);
		}

		/** Returns the singleton instance. */
		static ServiceConfigAccessor getInstance(Context context) {
		synchronized (SLOCK) {
		if (sInstance == null) {
		sInstance = new ServiceConfigAccessor(context);
		}
		return sInstance;
		}
		}
		public interface ServiceConfigAccessor {

		/**
		* Adds a listener that will be called when server flags related to this class change. The
		* callbacks are delivered on the main looper thread.
		* Adds a listener that will be invoked when {@link ConfigurationInternal} may have changed.
		* The listener is invoked on the main thread.
		*
		*
		* <p>Note: Only for use by long-lived objects. There is deliberately no associated remove
		* method.
		*/
		void addListener(@NonNull ConfigurationChangeListener listener) {
		mServerFlags.addListener(listener, SERVER_FLAGS_KEYS_TO_WATCH);
		}

		@NonNull
		@Origin int[] getOriginPriorities() {
		int[] serverFlagsValue = mServerFlagsOriginPrioritiesSupplier.get();
		if (serverFlagsValue != null) {
		return serverFlagsValue;
		}

		int[] configValue = mConfigOriginPrioritiesSupplier.get();
		if (configValue != null) {
		return configValue;
		}
		return DEFAULT_AUTOMATIC_TIME_ORIGIN_PRIORITIES;
		}

		int systemClockUpdateThresholdMillis() {
		return mSystemClockUpdateThresholdMillis;
		}

		@NonNull
		Instant autoTimeLowerBound() {
		return mServerFlags.getOptionalInstant(KEY_TIME_DETECTOR_LOWER_BOUND_MILLIS_OVERRIDE)
		.orElse(TIME_LOWER_BOUND_DEFAULT);
		}
		void addListener(@NonNull ConfigurationChangeListener listener);

		/**
		* A base supplier of an array of time origin integers in priority order.
		* It handles memoization of the result to avoid repeated string parsing when nothing has
		* changed.
		* Returns the absolute threshold below which the system clock need not be updated. i.e. if
		* setting the system clock would adjust it by less than this (either backwards or forwards)
		* then it need not be set.
		*/
		private abstract static class BaseOriginPrioritiesSupplier implements Supplier<@Origin int[]> {
		@GuardedBy("this") @Nullable private String[] mLastPriorityStrings;
		@GuardedBy("this") @Nullable private int[] mLastPriorityInts;

		/** Returns an array of {@code ORIGIN_} values, or {@code null}. /
		@Override
		@Nullable
		public @Origin int[] get() {
		String[] priorityStrings = lookupPriorityStrings();
		synchronized (this) {
		if (Arrays.equals(mLastPriorityStrings, priorityStrings)) {
		return mLastPriorityInts;
		}

		int[] priorityInts = null;
		if (priorityStrings != null && priorityStrings.length > 0) {
		priorityInts = new int[priorityStrings.length];
		try {
		for (int i = 0; i < priorityInts.length; i++) {
		String priorityString = priorityStrings[i];
		Preconditions.checkArgument(priorityString != null);

		priorityString = priorityString.trim();
		priorityInts[i] = TimeDetectorStrategy.stringToOrigin(priorityString);
		}
		} catch (IllegalArgumentException e) {
		// If any strings were bad and they were ignored then the semantics of the
		// whole list could change, so return null.
		priorityInts = null;
		}
		}
		mLastPriorityStrings = priorityStrings;
		mLastPriorityInts = priorityInts;
		return priorityInts;
		}
		}

		@Nullable
		protected abstract String[] lookupPriorityStrings();
		}

		/** Supplies origin priorities from config_autoTimeSourcesPriority. */
		private static class ConfigOriginPrioritiesSupplier extends BaseOriginPrioritiesSupplier {

		@NonNull private final Context mContext;

		private ConfigOriginPrioritiesSupplier(Context context) {
		mContext = Objects.requireNonNull(context);
		}

		@Override
		@Nullable
		protected String[] lookupPriorityStrings() {
		return mContext.getResources().getStringArray(R.array.config_autoTimeSourcesPriority);
		}
		}
		int systemClockUpdateThresholdMillis();

		/**
		* Supplies origin priorities from device_config (server flags), see
		* {@link ServerFlags#KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE}.
		* Returns a lower bound for valid automatic times. It is guaranteed to be in the past,
		* i.e. it is unrelated to the current system clock time.
		* It holds no other meaning; it could be related to when the device system image was built,
		* or could be updated by a mainline module.
		*/
		private static class ServerFlagsOriginPrioritiesSupplier extends BaseOriginPrioritiesSupplier {

		@NonNull private final ServerFlags mServerFlags;

		private ServerFlagsOriginPrioritiesSupplier(ServerFlags serverFlags) {
		mServerFlags = Objects.requireNonNull(serverFlags);
		}
		@NonNull
		Instant autoTimeLowerBound();

		@Override
		@Nullable
		protected String[] lookupPriorityStrings() {
		Optional<String[]> priorityStrings = mServerFlags.getOptionalStringArray(
		KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE);
		return priorityStrings.orElse(null);
		}
		}
		/**
		* Returns the order to look at time suggestions when automatically detecting time.
		* See {@code #ORIGIN_} constants
		*/
		@NonNull
		@Origin int[] getOriginPriorities();
		}

services/core/java/com/android/server/timedetector/ServiceConfigAccessorImpl.java

0 → 100644

+229 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2021 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 com.android.server.timedetector;

		import static com.android.server.timedetector.ServerFlags.KEY_TIME_DETECTOR_LOWER_BOUND_MILLIS_OVERRIDE;
		import static com.android.server.timedetector.ServerFlags.KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE;
		import static com.android.server.timedetector.TimeDetectorStrategy.ORIGIN_NETWORK;
		import static com.android.server.timedetector.TimeDetectorStrategy.ORIGIN_TELEPHONY;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.content.Context;
		import android.os.Build;
		import android.os.SystemProperties;

		import com.android.internal.R;
		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.util.Preconditions;
		import com.android.server.timedetector.TimeDetectorStrategy.Origin;
		import com.android.server.timezonedetector.ConfigurationChangeListener;

		import java.time.Instant;
		import java.util.Arrays;
		import java.util.Objects;
		import java.util.Optional;
		import java.util.Set;
		import java.util.function.Supplier;

		/**
		* A singleton implementation of {@link ServiceConfigAccessor}.
		*/
		final class ServiceConfigAccessorImpl implements ServiceConfigAccessor {

		private static final int SYSTEM_CLOCK_UPDATE_THRESHOLD_MILLIS_DEFAULT = 2 * 1000;

		/**
		* By default telephony and network only suggestions are accepted and telephony takes
		* precedence over network.
		*/
		private static final @Origin int[]
		DEFAULT_AUTOMATIC_TIME_ORIGIN_PRIORITIES = { ORIGIN_TELEPHONY, ORIGIN_NETWORK };

		/**
		* Time in the past. If an automatic time suggestion is before this point, it is sure to be
		* incorrect.
		*/
		private static final Instant TIME_LOWER_BOUND_DEFAULT = Instant.ofEpochMilli(
		Long.max(android.os.Environment.getRootDirectory().lastModified(), Build.TIME));

		/** Device config keys that affect the {@link TimeDetectorService}. */
		private static final Set<String> SERVER_FLAGS_KEYS_TO_WATCH = Set.of(
		KEY_TIME_DETECTOR_LOWER_BOUND_MILLIS_OVERRIDE,
		KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE
		);

		private static final Object SLOCK = new Object();

		/** The singleton instance. Initialized once in {@link #getInstance(Context)}. */
		@GuardedBy("SLOCK")
		@Nullable
		private static ServiceConfigAccessor sInstance;

		@NonNull private final Context mContext;
		@NonNull private final ServerFlags mServerFlags;
		@NonNull private final ConfigOriginPrioritiesSupplier mConfigOriginPrioritiesSupplier;
		@NonNull private final ServerFlagsOriginPrioritiesSupplier mServerFlagsOriginPrioritiesSupplier;

		/**
		* If a newly calculated system clock time and the current system clock time differs by this or
		* more the system clock will actually be updated. Used to prevent the system clock being set
		* for only minor differences.
		*/
		private final int mSystemClockUpdateThresholdMillis;

		private ServiceConfigAccessorImpl(@NonNull Context context) {
		mContext = Objects.requireNonNull(context);
		mServerFlags = ServerFlags.getInstance(mContext);
		mConfigOriginPrioritiesSupplier = new ConfigOriginPrioritiesSupplier(context);
		mServerFlagsOriginPrioritiesSupplier =
		new ServerFlagsOriginPrioritiesSupplier(mServerFlags);
		mSystemClockUpdateThresholdMillis =
		SystemProperties.getInt("ro.sys.time_detector_update_diff",
		SYSTEM_CLOCK_UPDATE_THRESHOLD_MILLIS_DEFAULT);
		}

		/** Returns the singleton instance. */
		static ServiceConfigAccessor getInstance(Context context) {
		synchronized (SLOCK) {
		if (sInstance == null) {
		sInstance = new ServiceConfigAccessorImpl(context);
		}
		return sInstance;
		}
		}

		/**
		* Adds a listener that will be called when server flags related to this class change. The
		* callbacks are delivered on the main looper thread.
		*
		* <p>Note: Only for use by long-lived objects. There is deliberately no associated remove
		* method.
		*/
		public void addListener(@NonNull ConfigurationChangeListener listener) {
		mServerFlags.addListener(listener, SERVER_FLAGS_KEYS_TO_WATCH);
		}

		@Override
		@NonNull
		public @Origin int[] getOriginPriorities() {
		int[] serverFlagsValue = mServerFlagsOriginPrioritiesSupplier.get();
		if (serverFlagsValue != null) {
		return serverFlagsValue;
		}

		int[] configValue = mConfigOriginPrioritiesSupplier.get();
		if (configValue != null) {
		return configValue;
		}
		return DEFAULT_AUTOMATIC_TIME_ORIGIN_PRIORITIES;
		}

		@Override
		public int systemClockUpdateThresholdMillis() {
		return mSystemClockUpdateThresholdMillis;
		}

		@Override
		@NonNull
		public Instant autoTimeLowerBound() {
		return mServerFlags.getOptionalInstant(KEY_TIME_DETECTOR_LOWER_BOUND_MILLIS_OVERRIDE)
		.orElse(TIME_LOWER_BOUND_DEFAULT);
		}

		/**
		* A base supplier of an array of time origin integers in priority order.
		* It handles memoization of the result to avoid repeated string parsing when nothing has
		* changed.
		*/
		private abstract static class BaseOriginPrioritiesSupplier implements Supplier<@Origin int[]> {
		@GuardedBy("this") @Nullable private String[] mLastPriorityStrings;
		@GuardedBy("this") @Nullable private int[] mLastPriorityInts;

		/** Returns an array of {@code ORIGIN_} values, or {@code null}. /
		@Override
		@Nullable
		public @Origin int[] get() {
		String[] priorityStrings = lookupPriorityStrings();
		synchronized (this) {
		if (Arrays.equals(mLastPriorityStrings, priorityStrings)) {
		return mLastPriorityInts;
		}

		int[] priorityInts = null;
		if (priorityStrings != null && priorityStrings.length > 0) {
		priorityInts = new int[priorityStrings.length];
		try {
		for (int i = 0; i < priorityInts.length; i++) {
		String priorityString = priorityStrings[i];
		Preconditions.checkArgument(priorityString != null);

		priorityString = priorityString.trim();
		priorityInts[i] = TimeDetectorStrategy.stringToOrigin(priorityString);
		}
		} catch (IllegalArgumentException e) {
		// If any strings were bad and they were ignored then the semantics of the
		// whole list could change, so return null.
		priorityInts = null;
		}
		}
		mLastPriorityStrings = priorityStrings;
		mLastPriorityInts = priorityInts;
		return priorityInts;
		}
		}

		@Nullable
		protected abstract String[] lookupPriorityStrings();
		}

		/** Supplies origin priorities from config_autoTimeSourcesPriority. */
		private static class ConfigOriginPrioritiesSupplier extends BaseOriginPrioritiesSupplier {

		@NonNull private final Context mContext;

		private ConfigOriginPrioritiesSupplier(Context context) {
		mContext = Objects.requireNonNull(context);
		}

		@Override
		@Nullable
		protected String[] lookupPriorityStrings() {
		return mContext.getResources().getStringArray(R.array.config_autoTimeSourcesPriority);
		}
		}

		/**
		* Supplies origin priorities from device_config (server flags), see
		* {@link ServerFlags#KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE}.
		*/
		private static class ServerFlagsOriginPrioritiesSupplier extends BaseOriginPrioritiesSupplier {

		@NonNull private final ServerFlags mServerFlags;

		private ServerFlagsOriginPrioritiesSupplier(ServerFlags serverFlags) {
		mServerFlags = Objects.requireNonNull(serverFlags);
		}

		@Override
		@Nullable
		protected String[] lookupPriorityStrings() {
		Optional<String[]> priorityStrings = mServerFlags.getOptionalStringArray(
		KEY_TIME_DETECTOR_ORIGIN_PRIORITIES_OVERRIDE);
		return priorityStrings.orElse(null);
		}
		}
		}

services/core/java/com/android/server/timedetector/TimeDetectorService.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -67,7 +67,7 @@ public final class TimeDetectorService extends ITimeDetectorService.Stub {
		Handler handler = FgThread.getHandler();

		ServiceConfigAccessor serviceConfigAccessor =
		ServiceConfigAccessor.getInstance(context);
		ServiceConfigAccessorImpl.getInstance(context);
		TimeDetectorStrategy timeDetectorStrategy =
		TimeDetectorStrategyImpl.create(context, handler, serviceConfigAccessor);