| /* |
| * 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.am; |
| |
| import android.content.ContentResolver; |
| import android.database.ContentObserver; |
| import android.os.Handler; |
| import android.provider.Settings; |
| import android.util.KeyValueListParser; |
| import android.util.Slog; |
| import android.util.TimeUtils; |
| |
| import java.io.PrintWriter; |
| |
| /** |
| * Tunable parameters for broadcast dispatch policy |
| */ |
| public class BroadcastConstants { |
| private static final String TAG = "BroadcastConstants"; |
| |
| // Value element names within the Settings record |
| static final String KEY_TIMEOUT = "bcast_timeout"; |
| static final String KEY_SLOW_TIME = "bcast_slow_time"; |
| static final String KEY_DEFERRAL = "bcast_deferral"; |
| static final String KEY_DEFERRAL_DECAY_FACTOR = "bcast_deferral_decay_factor"; |
| static final String KEY_DEFERRAL_FLOOR = "bcast_deferral_floor"; |
| |
| // All time intervals are in milliseconds |
| private static final long DEFAULT_TIMEOUT = 10_000; |
| private static final long DEFAULT_SLOW_TIME = 5_000; |
| private static final long DEFAULT_DEFERRAL = 5_000; |
| private static final float DEFAULT_DEFERRAL_DECAY_FACTOR = 0.75f; |
| private static final long DEFAULT_DEFERRAL_FLOOR = 0; |
| |
| // All time constants are in milliseconds |
| |
| // Timeout period for this broadcast queue |
| public long TIMEOUT = DEFAULT_TIMEOUT; |
| // Handling time above which we declare that a broadcast recipient was "slow". Any |
| // value <= zero is interpreted as disabling broadcast deferral policy entirely. |
| public long SLOW_TIME = DEFAULT_SLOW_TIME; |
| // How long to initially defer broadcasts, if an app is slow to handle one |
| public long DEFERRAL = DEFAULT_DEFERRAL; |
| // Decay factor for successive broadcasts' deferral time |
| public float DEFERRAL_DECAY_FACTOR = DEFAULT_DEFERRAL_DECAY_FACTOR; |
| // Minimum that the deferral time can decay to until the backlog fully clears |
| public long DEFERRAL_FLOOR = DEFAULT_DEFERRAL_FLOOR; |
| |
| // Settings override tracking for this instance |
| private String mSettingsKey; |
| private SettingsObserver mSettingsObserver; |
| private ContentResolver mResolver; |
| private final KeyValueListParser mParser = new KeyValueListParser(','); |
| |
| class SettingsObserver extends ContentObserver { |
| SettingsObserver(Handler handler) { |
| super(handler); |
| } |
| |
| @Override |
| public void onChange(boolean selfChange) { |
| updateConstants(); |
| } |
| } |
| |
| // A given constants instance is configured to observe specific keys from which |
| // that instance's values are drawn. |
| public BroadcastConstants(String settingsKey) { |
| mSettingsKey = settingsKey; |
| } |
| |
| /** |
| * Spin up the observer lazily, since it can only happen once the settings provider |
| * has been brought into service |
| */ |
| public void startObserving(Handler handler, ContentResolver resolver) { |
| mResolver = resolver; |
| |
| mSettingsObserver = new SettingsObserver(handler); |
| mResolver.registerContentObserver(Settings.Global.getUriFor(mSettingsKey), |
| false, mSettingsObserver); |
| |
| updateConstants(); |
| } |
| |
| private void updateConstants() { |
| synchronized (mParser) { |
| try { |
| mParser.setString(Settings.Global.getString(mResolver, mSettingsKey)); |
| } catch (IllegalArgumentException e) { |
| Slog.e(TAG, "Bad broadcast settings in key '" + mSettingsKey + "'", e); |
| return; |
| } |
| |
| // Unspecified fields retain their current value rather than revert to default |
| TIMEOUT = mParser.getLong(KEY_TIMEOUT, TIMEOUT); |
| SLOW_TIME = mParser.getLong(KEY_SLOW_TIME, SLOW_TIME); |
| DEFERRAL = mParser.getLong(KEY_DEFERRAL, DEFERRAL); |
| DEFERRAL_DECAY_FACTOR = mParser.getFloat(KEY_DEFERRAL_DECAY_FACTOR, |
| DEFERRAL_DECAY_FACTOR); |
| DEFERRAL_FLOOR = mParser.getLong(KEY_DEFERRAL_FLOOR, DEFERRAL_FLOOR); |
| } |
| } |
| |
| /** |
| * Standard dumpsys support; invoked from BroadcastQueue dump |
| */ |
| public void dump(PrintWriter pw) { |
| synchronized (mParser) { |
| pw.println(); |
| pw.print(" Broadcast parameters (key="); |
| pw.print(mSettingsKey); |
| pw.print(", observing="); |
| pw.print(mSettingsObserver != null); |
| pw.println("):"); |
| |
| pw.print(" "); pw.print(KEY_TIMEOUT); pw.print(" = "); |
| TimeUtils.formatDuration(TIMEOUT, pw); |
| pw.println(); |
| |
| pw.print(" "); pw.print(KEY_SLOW_TIME); pw.print(" = "); |
| TimeUtils.formatDuration(SLOW_TIME, pw); |
| pw.println(); |
| |
| pw.print(" "); pw.print(KEY_DEFERRAL); pw.print(" = "); |
| TimeUtils.formatDuration(DEFERRAL, pw); |
| pw.println(); |
| |
| pw.print(" "); pw.print(KEY_DEFERRAL_DECAY_FACTOR); pw.print(" = "); |
| pw.println(DEFERRAL_DECAY_FACTOR); |
| |
| pw.print(" "); pw.print(KEY_DEFERRAL_FLOOR); pw.print(" = "); |
| TimeUtils.formatDuration(DEFERRAL_FLOOR, pw); |
| pw.println(); |
| } |
| } |
| } |