| /* |
| * 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 com.android.server.timedetector; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.app.timedetector.ManualTimeSuggestion; |
| import android.app.timedetector.NetworkTimeSuggestion; |
| import android.app.timedetector.PhoneTimeSuggestion; |
| import android.content.Intent; |
| import android.os.TimestampedValue; |
| |
| import java.io.PrintWriter; |
| |
| /** |
| * The interface for classes that implement the time detection algorithm used by the |
| * TimeDetectorService. |
| * |
| * <p>Most calls will be handled by a single thread but that is not true for all calls. For example |
| * {@link #dump(PrintWriter, String[])}) may be called on a different thread so implementations must |
| * handle thread safety. |
| * |
| * @hide |
| */ |
| public interface TimeDetectorStrategy { |
| |
| /** |
| * The interface used by the strategy to interact with the surrounding service. |
| * |
| * <p>Note: Because the system properties-derived value {@link #isAutoTimeDetectionEnabled()} |
| * can be modified independently and from different threads (and processes!). its use is prone |
| * to race conditions. That will be true until the responsibility for setting their values is |
| * moved to {@link TimeDetectorStrategy}. There are similar issues with |
| * {@link #systemClockMillis()} while any process can modify the system clock. |
| */ |
| interface Callback { |
| |
| /** |
| * 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. |
| */ |
| int systemClockUpdateThresholdMillis(); |
| |
| /** Returns true if automatic time detection is enabled. */ |
| boolean isAutoTimeDetectionEnabled(); |
| |
| /** Acquire a suitable wake lock. Must be followed by {@link #releaseWakeLock()} */ |
| void acquireWakeLock(); |
| |
| /** Returns the elapsedRealtimeMillis clock value. The WakeLock must be held. */ |
| long elapsedRealtimeMillis(); |
| |
| /** Returns the system clock value. The WakeLock must be held. */ |
| long systemClockMillis(); |
| |
| /** Sets the device system clock. The WakeLock must be held. */ |
| void setSystemClock(long newTimeMillis); |
| |
| /** Release the wake lock acquired by a call to {@link #acquireWakeLock()}. */ |
| void releaseWakeLock(); |
| |
| /** Send the supplied intent as a stick broadcast. */ |
| void sendStickyBroadcast(@NonNull Intent intent); |
| } |
| |
| /** Initialize the strategy. */ |
| void initialize(@NonNull Callback callback); |
| |
| /** Process the suggested time from telephony sources. */ |
| void suggestPhoneTime(@NonNull PhoneTimeSuggestion timeSuggestion); |
| |
| /** Process the suggested manually entered time. */ |
| void suggestManualTime(@NonNull ManualTimeSuggestion timeSuggestion); |
| |
| /** Process the suggested time from network sources. */ |
| void suggestNetworkTime(@NonNull NetworkTimeSuggestion timeSuggestion); |
| |
| /** Handle the auto-time setting being toggled on or off. */ |
| void handleAutoTimeDetectionChanged(); |
| |
| /** Dump debug information. */ |
| void dump(@NonNull PrintWriter pw, @Nullable String[] args); |
| |
| // Utility methods below are to be moved to a better home when one becomes more obvious. |
| |
| /** |
| * Adjusts the supplied time value by applying the difference between the reference time |
| * supplied and the reference time associated with the time. |
| */ |
| static long getTimeAt(@NonNull TimestampedValue<Long> timeValue, long referenceClockMillisNow) { |
| return (referenceClockMillisNow - timeValue.getReferenceTimeMillis()) |
| + timeValue.getValue(); |
| } |
| } |