Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.cellbroadcastservice; |
| 18 | |
| 19 | import android.annotation.UnsupportedAppUsage; |
| 20 | import android.content.BroadcastReceiver; |
| 21 | import android.content.Context; |
| 22 | import android.content.Intent; |
| 23 | import android.os.Build; |
| 24 | import android.os.Message; |
| 25 | import android.os.PowerManager; |
| 26 | import android.util.Log; |
| 27 | |
| 28 | import com.android.internal.util.State; |
| 29 | import com.android.internal.util.StateMachine; |
| 30 | |
| 31 | import java.util.concurrent.atomic.AtomicInteger; |
| 32 | |
| 33 | /** |
| 34 | * Generic state machine for handling messages and waiting for ordered broadcasts to complete. |
| 35 | * Subclasses implement {@link #handleSmsMessage}, which returns true to transition into waiting |
| 36 | * state, or false to remain in idle state. The wakelock is acquired on exit from idle state, |
| 37 | * and is released a few seconds after returning to idle state, or immediately upon calling |
| 38 | * {@link #quit}. |
| 39 | */ |
| 40 | public abstract class WakeLockStateMachine extends StateMachine { |
| 41 | protected static final boolean DBG = Build.IS_DEBUGGABLE; |
| 42 | |
| 43 | private final PowerManager.WakeLock mWakeLock; |
| 44 | |
| 45 | /** New message to process. */ |
| 46 | public static final int EVENT_NEW_SMS_MESSAGE = 1; |
| 47 | |
| 48 | /** Result receiver called for current cell broadcast. */ |
| 49 | protected static final int EVENT_BROADCAST_COMPLETE = 2; |
| 50 | |
| 51 | /** Release wakelock after a short timeout when returning to idle state. */ |
| 52 | static final int EVENT_RELEASE_WAKE_LOCK = 3; |
| 53 | |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 54 | /** Broadcast not required due to geo-fencing check */ |
| 55 | static final int EVENT_BROADCAST_NOT_REQUIRED = 4; |
| 56 | |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 57 | @UnsupportedAppUsage |
| 58 | protected Context mContext; |
| 59 | |
| 60 | protected AtomicInteger mReceiverCount = new AtomicInteger(0); |
| 61 | |
| 62 | /** Wakelock release delay when returning to idle state. */ |
| 63 | private static final int WAKE_LOCK_TIMEOUT = 3000; |
| 64 | |
| 65 | private final DefaultState mDefaultState = new DefaultState(); |
| 66 | @UnsupportedAppUsage |
| 67 | private final IdleState mIdleState = new IdleState(); |
| 68 | private final WaitingState mWaitingState = new WaitingState(); |
| 69 | |
| 70 | protected WakeLockStateMachine(String debugTag, Context context) { |
| 71 | super(debugTag); |
| 72 | |
| 73 | mContext = context; |
| 74 | |
| 75 | PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE); |
| 76 | mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, debugTag); |
| 77 | // wake lock released after we enter idle state |
| 78 | mWakeLock.acquire(); |
| 79 | |
| 80 | addState(mDefaultState); |
| 81 | addState(mIdleState, mDefaultState); |
| 82 | addState(mWaitingState, mDefaultState); |
| 83 | setInitialState(mIdleState); |
| 84 | } |
| 85 | |
| 86 | private void releaseWakeLock() { |
| 87 | if (mWakeLock.isHeld()) { |
| 88 | mWakeLock.release(); |
| 89 | } |
| 90 | |
| 91 | if (mWakeLock.isHeld()) { |
| 92 | loge("Wait lock is held after release."); |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Tell the state machine to quit after processing all messages. |
| 98 | */ |
| 99 | public final void dispose() { |
| 100 | quit(); |
| 101 | } |
| 102 | |
| 103 | @Override |
| 104 | protected void onQuitting() { |
| 105 | // fully release the wakelock |
| 106 | while (mWakeLock.isHeld()) { |
| 107 | mWakeLock.release(); |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * Send a message with the specified object for {@link #handleSmsMessage}. |
| 113 | * @param obj the object to pass in the msg.obj field |
| 114 | */ |
| 115 | public final void onCdmaCellBroadcastSms(Object obj) { |
| 116 | sendMessage(EVENT_NEW_SMS_MESSAGE, obj); |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * This parent state throws an exception (for debug builds) or prints an error for unhandled |
| 121 | * message types. |
| 122 | */ |
| 123 | class DefaultState extends State { |
| 124 | @Override |
| 125 | public boolean processMessage(Message msg) { |
| 126 | switch (msg.what) { |
| 127 | default: { |
| 128 | String errorText = "processMessage: unhandled message type " + msg.what; |
| 129 | if (Build.IS_DEBUGGABLE) { |
| 130 | throw new RuntimeException(errorText); |
| 131 | } else { |
| 132 | loge(errorText); |
| 133 | } |
| 134 | break; |
| 135 | } |
| 136 | } |
| 137 | return HANDLED; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | /** |
| 142 | * Idle state delivers Cell Broadcasts to receivers. It acquires the wakelock, which is |
| 143 | * released when the broadcast completes. |
| 144 | */ |
| 145 | class IdleState extends State { |
| 146 | @Override |
| 147 | public void enter() { |
| 148 | sendMessageDelayed(EVENT_RELEASE_WAKE_LOCK, WAKE_LOCK_TIMEOUT); |
| 149 | } |
| 150 | |
| 151 | @Override |
| 152 | public void exit() { |
| 153 | mWakeLock.acquire(); |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 154 | if (DBG) log("Idle: acquired wakelock, leaving Idle state"); |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 155 | } |
| 156 | |
| 157 | @Override |
| 158 | public boolean processMessage(Message msg) { |
| 159 | switch (msg.what) { |
| 160 | case EVENT_NEW_SMS_MESSAGE: |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 161 | log("Idle: new cell broadcast message"); |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 162 | // transition to waiting state if we sent a broadcast |
| 163 | if (handleSmsMessage(msg)) { |
| 164 | transitionTo(mWaitingState); |
| 165 | } |
| 166 | return HANDLED; |
| 167 | |
| 168 | case EVENT_RELEASE_WAKE_LOCK: |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 169 | log("Idle: release wakelock"); |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 170 | releaseWakeLock(); |
| 171 | return HANDLED; |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 172 | case EVENT_BROADCAST_NOT_REQUIRED: |
| 173 | log("Idle: broadcast not required"); |
| 174 | return HANDLED; |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 175 | default: |
| 176 | return NOT_HANDLED; |
| 177 | } |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | /** |
| 182 | * Waiting state waits for the result receiver to be called for the current cell broadcast. |
| 183 | * In this state, any new cell broadcasts are deferred until we return to Idle state. |
| 184 | */ |
| 185 | class WaitingState extends State { |
| 186 | @Override |
| 187 | public boolean processMessage(Message msg) { |
| 188 | switch (msg.what) { |
| 189 | case EVENT_NEW_SMS_MESSAGE: |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 190 | log("Waiting: deferring message until return to idle"); |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 191 | deferMessage(msg); |
| 192 | return HANDLED; |
| 193 | |
| 194 | case EVENT_BROADCAST_COMPLETE: |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 195 | log("Waiting: broadcast complete, returning to idle"); |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 196 | transitionTo(mIdleState); |
| 197 | return HANDLED; |
| 198 | |
| 199 | case EVENT_RELEASE_WAKE_LOCK: |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 200 | log("Waiting: release wakelock"); |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 201 | releaseWakeLock(); |
| 202 | return HANDLED; |
Jack Yu | 2f37c43 | 2019-11-04 21:28:24 -0800 | [diff] [blame] | 203 | case EVENT_BROADCAST_NOT_REQUIRED: |
| 204 | log("Waiting: broadcast not required"); |
| 205 | if (mReceiverCount.get() == 0) { |
| 206 | transitionTo(mIdleState); |
| 207 | } |
| 208 | return HANDLED; |
Jordan Liu | c872fad | 2019-10-11 11:42:03 -0700 | [diff] [blame] | 209 | default: |
| 210 | return NOT_HANDLED; |
| 211 | } |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * Implemented by subclass to handle messages in {@link IdleState}. |
| 217 | * @param message the message to process |
| 218 | * @return true to transition to {@link WaitingState}; false to stay in {@link IdleState} |
| 219 | */ |
| 220 | protected abstract boolean handleSmsMessage(Message message); |
| 221 | |
| 222 | /** |
| 223 | * BroadcastReceiver to send message to return to idle state. |
| 224 | */ |
| 225 | protected final BroadcastReceiver mReceiver = new BroadcastReceiver() { |
| 226 | @Override |
| 227 | public void onReceive(Context context, Intent intent) { |
| 228 | if (mReceiverCount.decrementAndGet() == 0) { |
| 229 | sendMessage(EVENT_BROADCAST_COMPLETE); |
| 230 | } |
| 231 | } |
| 232 | }; |
| 233 | |
| 234 | /** |
| 235 | * Log with debug level. |
| 236 | * @param s the string to log |
| 237 | */ |
| 238 | @UnsupportedAppUsage |
| 239 | @Override |
| 240 | protected void log(String s) { |
| 241 | Log.d(getName(), s); |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * Log with error level. |
| 246 | * @param s the string to log |
| 247 | */ |
| 248 | @Override |
| 249 | protected void loge(String s) { |
| 250 | Log.e(getName(), s); |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * Log with error level. |
| 255 | * @param s the string to log |
| 256 | * @param e is a Throwable which logs additional information. |
| 257 | */ |
| 258 | @Override |
| 259 | protected void loge(String s, Throwable e) { |
| 260 | Log.e(getName(), s, e); |
| 261 | } |
| 262 | } |