PowerManager.java revision 3d658bf20e2d56e36941e7407deebeec1276fbcf
1/* 2 * Copyright (C) 2007 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 17package android.os; 18 19import android.content.Context; 20import android.util.Log; 21 22/** 23 * This class gives you control of the power state of the device. 24 * 25 * <p> 26 * <b>Device battery life will be significantly affected by the use of this API.</b> 27 * Do not acquire {@link WakeLock}s unless you really need them, use the minimum levels 28 * possible, and be sure to release them as soon as possible. 29 * </p><p> 30 * You can obtain an instance of this class by calling 31 * {@link android.content.Context#getSystemService(java.lang.String) Context.getSystemService()}. 32 * </p><p> 33 * The primary API you'll use is {@link #newWakeLock(int, String) newWakeLock()}. 34 * This will create a {@link PowerManager.WakeLock} object. You can then use methods 35 * on the wake lock object to control the power state of the device. 36 * </p><p> 37 * In practice it's quite simple: 38 * {@samplecode 39 * PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); 40 * PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag"); 41 * wl.acquire(); 42 * ..screen will stay on during this section.. 43 * wl.release(); 44 * } 45 * </p><p> 46 * The following wake lock levels are defined, with varying effects on system power. 47 * <i>These levels are mutually exclusive - you may only specify one of them.</i> 48 * 49 * <table> 50 * <tr><th>Flag Value</th> 51 * <th>CPU</th> <th>Screen</th> <th>Keyboard</th></tr> 52 * 53 * <tr><td>{@link #PARTIAL_WAKE_LOCK}</td> 54 * <td>On*</td> <td>Off</td> <td>Off</td> 55 * </tr> 56 * 57 * <tr><td>{@link #SCREEN_DIM_WAKE_LOCK}</td> 58 * <td>On</td> <td>Dim</td> <td>Off</td> 59 * </tr> 60 * 61 * <tr><td>{@link #SCREEN_BRIGHT_WAKE_LOCK}</td> 62 * <td>On</td> <td>Bright</td> <td>Off</td> 63 * </tr> 64 * 65 * <tr><td>{@link #FULL_WAKE_LOCK}</td> 66 * <td>On</td> <td>Bright</td> <td>Bright</td> 67 * </tr> 68 * </table> 69 * </p><p> 70 * *<i>If you hold a partial wake lock, the CPU will continue to run, regardless of any 71 * display timeouts or the state of the screen and even after the user presses the power button. 72 * In all other wake locks, the CPU will run, but the user can still put the device to sleep 73 * using the power button.</i> 74 * </p><p> 75 * In addition, you can add two more flags, which affect behavior of the screen only. 76 * <i>These flags have no effect when combined with a {@link #PARTIAL_WAKE_LOCK}.</i></p> 77 * 78 * <table> 79 * <tr><th>Flag Value</th> <th>Description</th></tr> 80 * 81 * <tr><td>{@link #ACQUIRE_CAUSES_WAKEUP}</td> 82 * <td>Normal wake locks don't actually turn on the illumination. Instead, they cause 83 * the illumination to remain on once it turns on (e.g. from user activity). This flag 84 * will force the screen and/or keyboard to turn on immediately, when the WakeLock is 85 * acquired. A typical use would be for notifications which are important for the user to 86 * see immediately.</td> 87 * </tr> 88 * 89 * <tr><td>{@link #ON_AFTER_RELEASE}</td> 90 * <td>If this flag is set, the user activity timer will be reset when the WakeLock is 91 * released, causing the illumination to remain on a bit longer. This can be used to 92 * reduce flicker if you are cycling between wake lock conditions.</td> 93 * </tr> 94 * </table> 95 * <p> 96 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 97 * permission in an {@code <uses-permission>} element of the application's manifest. 98 * </p> 99 */ 100public final class PowerManager { 101 private static final String TAG = "PowerManager"; 102 103 /* NOTE: Wake lock levels were previously defined as a bit field, except that only a few 104 * combinations were actually supported so the bit field was removed. This explains 105 * why the numbering scheme is so odd. If adding a new wake lock level, any unused 106 * value can be used. 107 */ 108 109 /** 110 * Wake lock level: Ensures that the CPU is running; the screen and keyboard 111 * backlight will be allowed to go off. 112 * <p> 113 * If the user presses the power button, then the screen will be turned off 114 * but the CPU will be kept on until all partial wake locks have been released. 115 * </p> 116 */ 117 public static final int PARTIAL_WAKE_LOCK = 0x00000001; 118 119 /** 120 * Wake lock level: Ensures that the screen is on (but may be dimmed); 121 * the keyboard backlight will be allowed to go off. 122 * <p> 123 * If the user presses the power button, then the {@link #SCREEN_DIM_WAKE_LOCK} will be 124 * implicitly released by the system, causing both the screen and the CPU to be turned off. 125 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 126 * </p> 127 * 128 * @deprecated Most applications should use 129 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 130 * of this type of wake lock, as it will be correctly managed by the platform 131 * as the user moves between applications and doesn't require a special permission. 132 */ 133 @Deprecated 134 public static final int SCREEN_DIM_WAKE_LOCK = 0x00000006; 135 136 /** 137 * Wake lock level: Ensures that the screen is on at full brightness; 138 * the keyboard backlight will be allowed to go off. 139 * <p> 140 * If the user presses the power button, then the {@link #SCREEN_BRIGHT_WAKE_LOCK} will be 141 * implicitly released by the system, causing both the screen and the CPU to be turned off. 142 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 143 * </p> 144 * 145 * @deprecated Most applications should use 146 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 147 * of this type of wake lock, as it will be correctly managed by the platform 148 * as the user moves between applications and doesn't require a special permission. 149 */ 150 @Deprecated 151 public static final int SCREEN_BRIGHT_WAKE_LOCK = 0x0000000a; 152 153 /** 154 * Wake lock level: Ensures that the screen and keyboard backlight are on at 155 * full brightness. 156 * <p> 157 * If the user presses the power button, then the {@link #FULL_WAKE_LOCK} will be 158 * implicitly released by the system, causing both the screen and the CPU to be turned off. 159 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 160 * </p> 161 * 162 * @deprecated Most applications should use 163 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 164 * of this type of wake lock, as it will be correctly managed by the platform 165 * as the user moves between applications and doesn't require a special permission. 166 */ 167 @Deprecated 168 public static final int FULL_WAKE_LOCK = 0x0000001a; 169 170 /** 171 * Wake lock level: Turns the screen off when the proximity sensor activates. 172 * <p> 173 * If the proximity sensor detects that an object is nearby, the screen turns off 174 * immediately. Shortly after the object moves away, the screen turns on again. 175 * </p><p> 176 * A proximity wake lock does not prevent the device from falling asleep 177 * unlike {@link #FULL_WAKE_LOCK}, {@link #SCREEN_BRIGHT_WAKE_LOCK} and 178 * {@link #SCREEN_DIM_WAKE_LOCK}. If there is no user activity and no other 179 * wake locks are held, then the device will fall asleep (and lock) as usual. 180 * However, the device will not fall asleep while the screen has been turned off 181 * by the proximity sensor because it effectively counts as ongoing user activity. 182 * </p><p> 183 * Since not all devices have proximity sensors, use {@link #isWakeLockLevelSupported} 184 * to determine whether this wake lock level is supported. 185 * </p><p> 186 * Cannot be used with {@link #ACQUIRE_CAUSES_WAKEUP}. 187 * </p> 188 * 189 * {@hide} 190 */ 191 public static final int PROXIMITY_SCREEN_OFF_WAKE_LOCK = 0x00000020; 192 193 /** 194 * Mask for the wake lock level component of a combined wake lock level and flags integer. 195 * 196 * @hide 197 */ 198 public static final int WAKE_LOCK_LEVEL_MASK = 0x0000ffff; 199 200 /** 201 * Wake lock flag: Turn the screen on when the wake lock is acquired. 202 * <p> 203 * Normally wake locks don't actually wake the device, they just cause 204 * the screen to remain on once it's already on. Think of the video player 205 * application as the normal behavior. Notifications that pop up and want 206 * the device to be on are the exception; use this flag to be like them. 207 * </p><p> 208 * Cannot be used with {@link #PARTIAL_WAKE_LOCK}. 209 * </p> 210 */ 211 public static final int ACQUIRE_CAUSES_WAKEUP = 0x10000000; 212 213 /** 214 * Wake lock flag: When this wake lock is released, poke the user activity timer 215 * so the screen stays on for a little longer. 216 * <p> 217 * Will not turn the screen on if it is not already on. 218 * See {@link #ACQUIRE_CAUSES_WAKEUP} if you want that. 219 * </p><p> 220 * Cannot be used with {@link #PARTIAL_WAKE_LOCK}. 221 * </p> 222 */ 223 public static final int ON_AFTER_RELEASE = 0x20000000; 224 225 /** 226 * Wake lock flag: This wake lock is not important for logging events. If a later 227 * wake lock is acquired that is important, it will be considered the one to log. 228 * @hide 229 */ 230 public static final int UNIMPORTANT_FOR_LOGGING = 0x40000000; 231 232 /** 233 * Flag for {@link WakeLock#release release(int)} to defer releasing a 234 * {@link #PROXIMITY_SCREEN_OFF_WAKE_LOCK} wake lock until the proximity sensor returns 235 * a negative value. 236 * 237 * {@hide} 238 */ 239 public static final int WAIT_FOR_PROXIMITY_NEGATIVE = 1; 240 241 /** 242 * Brightness value for fully on. 243 * @hide 244 */ 245 public static final int BRIGHTNESS_ON = 255; 246 247 /** 248 * Brightness value for fully off. 249 * @hide 250 */ 251 public static final int BRIGHTNESS_OFF = 0; 252 253 // Note: Be sure to update android.os.BatteryStats and PowerManager.h 254 // if adding or modifying user activity event constants. 255 256 /** 257 * User activity event type: Unspecified event type. 258 * @hide 259 */ 260 public static final int USER_ACTIVITY_EVENT_OTHER = 0; 261 262 /** 263 * User activity event type: Button or key pressed or released. 264 * @hide 265 */ 266 public static final int USER_ACTIVITY_EVENT_BUTTON = 1; 267 268 /** 269 * User activity event type: Touch down, move or up. 270 * @hide 271 */ 272 public static final int USER_ACTIVITY_EVENT_TOUCH = 2; 273 274 /** 275 * User activity flag: Do not restart the user activity timeout or brighten 276 * the display in response to user activity if it is already dimmed. 277 * @hide 278 */ 279 public static final int USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS = 1 << 0; 280 281 /** 282 * Go to sleep reason code: Going to sleep due by user request. 283 * @hide 284 */ 285 public static final int GO_TO_SLEEP_REASON_USER = 0; 286 287 /** 288 * Go to sleep reason code: Going to sleep due by request of the 289 * device administration policy. 290 * @hide 291 */ 292 public static final int GO_TO_SLEEP_REASON_DEVICE_ADMIN = 1; 293 294 /** 295 * Go to sleep reason code: Going to sleep due to a screen timeout. 296 * @hide 297 */ 298 public static final int GO_TO_SLEEP_REASON_TIMEOUT = 2; 299 300 /** 301 * The value to pass as the 'reason' argument to reboot() to 302 * reboot into recovery mode (for applying system updates, doing 303 * factory resets, etc.). 304 * <p> 305 * Requires the {@link android.Manifest.permission#RECOVERY} 306 * permission (in addition to 307 * {@link android.Manifest.permission#REBOOT}). 308 * </p> 309 */ 310 public static final String REBOOT_RECOVERY = "recovery"; 311 312 final Context mContext; 313 final IPowerManager mService; 314 final Handler mHandler; 315 316 /** 317 * {@hide} 318 */ 319 public PowerManager(Context context, IPowerManager service, Handler handler) { 320 mContext = context; 321 mService = service; 322 mHandler = handler; 323 } 324 325 /** 326 * Gets the minimum supported screen brightness setting. 327 * The screen may be allowed to become dimmer than this value but 328 * this is the minimum value that can be set by the user. 329 * @hide 330 */ 331 public int getMinimumScreenBrightnessSetting() { 332 return mContext.getResources().getInteger( 333 com.android.internal.R.integer.config_screenBrightnessSettingMinimum); 334 } 335 336 /** 337 * Gets the maximum supported screen brightness setting. 338 * The screen may be allowed to become dimmer than this value but 339 * this is the maximum value that can be set by the user. 340 * @hide 341 */ 342 public int getMaximumScreenBrightnessSetting() { 343 return mContext.getResources().getInteger( 344 com.android.internal.R.integer.config_screenBrightnessSettingMaximum); 345 } 346 347 /** 348 * Gets the default screen brightness setting. 349 * @hide 350 */ 351 public int getDefaultScreenBrightnessSetting() { 352 return mContext.getResources().getInteger( 353 com.android.internal.R.integer.config_screenBrightnessSettingDefault); 354 } 355 356 /** 357 * Returns true if the screen auto-brightness adjustment setting should 358 * be available in the UI. This setting is experimental and disabled by default. 359 * @hide 360 */ 361 public static boolean useScreenAutoBrightnessAdjustmentFeature() { 362 return SystemProperties.getBoolean("persist.power.useautobrightadj", false); 363 } 364 365 /** 366 * Returns true if the twilight service should be used to adjust screen brightness 367 * policy. This setting is experimental and disabled by default. 368 * @hide 369 */ 370 public static boolean useTwilightAdjustmentFeature() { 371 return SystemProperties.getBoolean("persist.power.usetwilightadj", false); 372 } 373 374 /** 375 * Creates a new wake lock with the specified level and flags. 376 * <p> 377 * The {@code levelAndFlags} parameter specifies a wake lock level and optional flags 378 * combined using the logical OR operator. 379 * </p><p> 380 * The wake lock levels are: {@link #PARTIAL_WAKE_LOCK}, 381 * {@link #FULL_WAKE_LOCK}, {@link #SCREEN_DIM_WAKE_LOCK} 382 * and {@link #SCREEN_BRIGHT_WAKE_LOCK}. Exactly one wake lock level must be 383 * specified as part of the {@code levelAndFlags} parameter. 384 * </p><p> 385 * The wake lock flags are: {@link #ACQUIRE_CAUSES_WAKEUP} 386 * and {@link #ON_AFTER_RELEASE}. Multiple flags can be combined as part of the 387 * {@code levelAndFlags} parameters. 388 * </p><p> 389 * Call {@link WakeLock#acquire() acquire()} on the object to acquire the 390 * wake lock, and {@link WakeLock#release release()} when you are done. 391 * </p><p> 392 * {@samplecode 393 * PowerManager pm = (PowerManager)mContext.getSystemService( 394 * Context.POWER_SERVICE); 395 * PowerManager.WakeLock wl = pm.newWakeLock( 396 * PowerManager.SCREEN_DIM_WAKE_LOCK 397 * | PowerManager.ON_AFTER_RELEASE, 398 * TAG); 399 * wl.acquire(); 400 * // ... do work... 401 * wl.release(); 402 * } 403 * </p><p> 404 * Although a wake lock can be created without special permissions, 405 * the {@link android.Manifest.permission#WAKE_LOCK} permission is 406 * required to actually acquire or release the wake lock that is returned. 407 * </p><p class="note"> 408 * If using this to keep the screen on, you should strongly consider using 409 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead. 410 * This window flag will be correctly managed by the platform 411 * as the user moves between applications and doesn't require a special permission. 412 * </p> 413 * 414 * @param levelAndFlags Combination of wake lock level and flag values defining 415 * the requested behavior of the WakeLock. 416 * @param tag Your class name (or other tag) for debugging purposes. 417 * 418 * @see WakeLock#acquire() 419 * @see WakeLock#release() 420 * @see #PARTIAL_WAKE_LOCK 421 * @see #FULL_WAKE_LOCK 422 * @see #SCREEN_DIM_WAKE_LOCK 423 * @see #SCREEN_BRIGHT_WAKE_LOCK 424 * @see #ACQUIRE_CAUSES_WAKEUP 425 * @see #ON_AFTER_RELEASE 426 */ 427 public WakeLock newWakeLock(int levelAndFlags, String tag) { 428 validateWakeLockParameters(levelAndFlags, tag); 429 return new WakeLock(levelAndFlags, tag, mContext.getOpPackageName()); 430 } 431 432 /** @hide */ 433 public static void validateWakeLockParameters(int levelAndFlags, String tag) { 434 switch (levelAndFlags & WAKE_LOCK_LEVEL_MASK) { 435 case PARTIAL_WAKE_LOCK: 436 case SCREEN_DIM_WAKE_LOCK: 437 case SCREEN_BRIGHT_WAKE_LOCK: 438 case FULL_WAKE_LOCK: 439 case PROXIMITY_SCREEN_OFF_WAKE_LOCK: 440 break; 441 default: 442 throw new IllegalArgumentException("Must specify a valid wake lock level."); 443 } 444 if (tag == null) { 445 throw new IllegalArgumentException("The tag must not be null."); 446 } 447 } 448 449 /** 450 * Notifies the power manager that user activity happened. 451 * <p> 452 * Resets the auto-off timer and brightens the screen if the device 453 * is not asleep. This is what happens normally when a key or the touch 454 * screen is pressed or when some other user activity occurs. 455 * This method does not wake up the device if it has been put to sleep. 456 * </p><p> 457 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 458 * </p> 459 * 460 * @param when The time of the user activity, in the {@link SystemClock#uptimeMillis()} 461 * time base. This timestamp is used to correctly order the user activity request with 462 * other power management functions. It should be set 463 * to the timestamp of the input event that caused the user activity. 464 * @param noChangeLights If true, does not cause the keyboard backlight to turn on 465 * because of this event. This is set when the power key is pressed. 466 * We want the device to stay on while the button is down, but we're about 467 * to turn off the screen so we don't want the keyboard backlight to turn on again. 468 * Otherwise the lights flash on and then off and it looks weird. 469 * 470 * @see #wakeUp 471 * @see #goToSleep 472 */ 473 public void userActivity(long when, boolean noChangeLights) { 474 try { 475 mService.userActivity(when, USER_ACTIVITY_EVENT_OTHER, 476 noChangeLights ? USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS : 0); 477 } catch (RemoteException e) { 478 } 479 } 480 481 /** 482 * Forces the device to go to sleep. 483 * <p> 484 * Overrides all the wake locks that are held. 485 * This is what happens when the power key is pressed to turn off the screen. 486 * </p><p> 487 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 488 * </p> 489 * 490 * @param time The time when the request to go to sleep was issued, in the 491 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 492 * order the go to sleep request with other power management functions. It should be set 493 * to the timestamp of the input event that caused the request to go to sleep. 494 * 495 * @see #userActivity 496 * @see #wakeUp 497 */ 498 public void goToSleep(long time) { 499 try { 500 mService.goToSleep(time, GO_TO_SLEEP_REASON_USER); 501 } catch (RemoteException e) { 502 } 503 } 504 505 /** 506 * Forces the device to wake up from sleep. 507 * <p> 508 * If the device is currently asleep, wakes it up, otherwise does nothing. 509 * This is what happens when the power key is pressed to turn on the screen. 510 * </p><p> 511 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 512 * </p> 513 * 514 * @param time The time when the request to wake up was issued, in the 515 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 516 * order the wake up request with other power management functions. It should be set 517 * to the timestamp of the input event that caused the request to wake up. 518 * 519 * @see #userActivity 520 * @see #goToSleep 521 */ 522 public void wakeUp(long time) { 523 try { 524 mService.wakeUp(time); 525 } catch (RemoteException e) { 526 } 527 } 528 529 /** 530 * Forces the device to start napping. 531 * <p> 532 * If the device is currently awake, starts dreaming, otherwise does nothing. 533 * When the dream ends or if the dream cannot be started, the device will 534 * either wake up or go to sleep depending on whether there has been recent 535 * user activity. 536 * </p><p> 537 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 538 * </p> 539 * 540 * @param time The time when the request to nap was issued, in the 541 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 542 * order the nap request with other power management functions. It should be set 543 * to the timestamp of the input event that caused the request to nap. 544 * 545 * @see #wakeUp 546 * @see #goToSleep 547 * 548 * @hide 549 */ 550 public void nap(long time) { 551 try { 552 mService.nap(time); 553 } catch (RemoteException e) { 554 } 555 } 556 557 /** 558 * Sets the brightness of the backlights (screen, keyboard, button). 559 * <p> 560 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 561 * </p> 562 * 563 * @param brightness The brightness value from 0 to 255. 564 * 565 * {@hide} 566 */ 567 public void setBacklightBrightness(int brightness) { 568 try { 569 mService.setTemporaryScreenBrightnessSettingOverride(brightness); 570 } catch (RemoteException e) { 571 } 572 } 573 574 /** 575 * Returns true if the specified wake lock level is supported. 576 * 577 * @param level The wake lock level to check. 578 * @return True if the specified wake lock level is supported. 579 * 580 * {@hide} 581 */ 582 public boolean isWakeLockLevelSupported(int level) { 583 try { 584 return mService.isWakeLockLevelSupported(level); 585 } catch (RemoteException e) { 586 return false; 587 } 588 } 589 590 /** 591 * Returns whether the screen is currently on. 592 * <p> 593 * Only indicates whether the screen is on. The screen could be either bright or dim. 594 * </p><p> 595 * {@samplecode 596 * PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); 597 * boolean isScreenOn = pm.isScreenOn(); 598 * } 599 * </p> 600 * 601 * @return whether the screen is on (bright or dim). 602 */ 603 public boolean isScreenOn() { 604 try { 605 return mService.isScreenOn(); 606 } catch (RemoteException e) { 607 return false; 608 } 609 } 610 611 /** 612 * Reboot the device. Will not return if the reboot is successful. 613 * <p> 614 * Requires the {@link android.Manifest.permission#REBOOT} permission. 615 * </p> 616 * 617 * @param reason code to pass to the kernel (e.g., "recovery") to 618 * request special boot modes, or null. 619 */ 620 public void reboot(String reason) { 621 try { 622 mService.reboot(false, reason, true); 623 } catch (RemoteException e) { 624 } 625 } 626 627 /** 628 * A wake lock is a mechanism to indicate that your application needs 629 * to have the device stay on. 630 * <p> 631 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 632 * permission in an {@code <uses-permission>} element of the application's manifest. 633 * Obtain a wake lock by calling {@link PowerManager#newWakeLock(int, String)}. 634 * </p><p> 635 * Call {@link #acquire()} to acquire the wake lock and force the device to stay 636 * on at the level that was requested when the wake lock was created. 637 * </p><p> 638 * Call {@link #release()} when you are done and don't need the lock anymore. 639 * It is very important to do this as soon as possible to avoid running down the 640 * device's battery excessively. 641 * </p> 642 */ 643 public final class WakeLock { 644 private int mFlags; 645 private String mTag; 646 private final String mPackageName; 647 private final IBinder mToken; 648 private int mCount; 649 private boolean mRefCounted = true; 650 private boolean mHeld; 651 private WorkSource mWorkSource; 652 653 private final Runnable mReleaser = new Runnable() { 654 public void run() { 655 release(); 656 } 657 }; 658 659 WakeLock(int flags, String tag, String packageName) { 660 mFlags = flags; 661 mTag = tag; 662 mPackageName = packageName; 663 mToken = new Binder(); 664 } 665 666 @Override 667 protected void finalize() throws Throwable { 668 synchronized (mToken) { 669 if (mHeld) { 670 Log.wtf(TAG, "WakeLock finalized while still held: " + mTag); 671 try { 672 mService.releaseWakeLock(mToken, 0); 673 } catch (RemoteException e) { 674 } 675 } 676 } 677 } 678 679 /** 680 * Sets whether this WakeLock is reference counted. 681 * <p> 682 * Wake locks are reference counted by default. If a wake lock is 683 * reference counted, then each call to {@link #acquire()} must be 684 * balanced by an equal number of calls to {@link #release()}. If a wake 685 * lock is not reference counted, then one call to {@link #release()} is 686 * sufficient to undo the effect of all previous calls to {@link #acquire()}. 687 * </p> 688 * 689 * @param value True to make the wake lock reference counted, false to 690 * make the wake lock non-reference counted. 691 */ 692 public void setReferenceCounted(boolean value) { 693 synchronized (mToken) { 694 mRefCounted = value; 695 } 696 } 697 698 /** 699 * Acquires the wake lock. 700 * <p> 701 * Ensures that the device is on at the level requested when 702 * the wake lock was created. 703 * </p> 704 */ 705 public void acquire() { 706 synchronized (mToken) { 707 acquireLocked(); 708 } 709 } 710 711 /** 712 * Acquires the wake lock with a timeout. 713 * <p> 714 * Ensures that the device is on at the level requested when 715 * the wake lock was created. The lock will be released after the given timeout 716 * expires. 717 * </p> 718 * 719 * @param timeout The timeout after which to release the wake lock, in milliseconds. 720 */ 721 public void acquire(long timeout) { 722 synchronized (mToken) { 723 acquireLocked(); 724 mHandler.postDelayed(mReleaser, timeout); 725 } 726 } 727 728 private void acquireLocked() { 729 if (!mRefCounted || mCount++ == 0) { 730 // Do this even if the wake lock is already thought to be held (mHeld == true) 731 // because non-reference counted wake locks are not always properly released. 732 // For example, the keyguard's wake lock might be forcibly released by the 733 // power manager without the keyguard knowing. A subsequent call to acquire 734 // should immediately acquire the wake lock once again despite never having 735 // been explicitly released by the keyguard. 736 mHandler.removeCallbacks(mReleaser); 737 try { 738 mService.acquireWakeLock(mToken, mFlags, mTag, mPackageName, mWorkSource); 739 } catch (RemoteException e) { 740 } 741 mHeld = true; 742 } 743 } 744 745 /** 746 * Releases the wake lock. 747 * <p> 748 * This method releases your claim to the CPU or screen being on. 749 * The screen may turn off shortly after you release the wake lock, or it may 750 * not if there are other wake locks still held. 751 * </p> 752 */ 753 public void release() { 754 release(0); 755 } 756 757 /** 758 * Releases the wake lock with flags to modify the release behavior. 759 * <p> 760 * This method releases your claim to the CPU or screen being on. 761 * The screen may turn off shortly after you release the wake lock, or it may 762 * not if there are other wake locks still held. 763 * </p> 764 * 765 * @param flags Combination of flag values to modify the release behavior. 766 * Currently only {@link #WAIT_FOR_PROXIMITY_NEGATIVE} is supported. 767 * 768 * {@hide} 769 */ 770 public void release(int flags) { 771 synchronized (mToken) { 772 if (!mRefCounted || --mCount == 0) { 773 mHandler.removeCallbacks(mReleaser); 774 if (mHeld) { 775 try { 776 mService.releaseWakeLock(mToken, flags); 777 } catch (RemoteException e) { 778 } 779 mHeld = false; 780 } 781 } 782 if (mCount < 0) { 783 throw new RuntimeException("WakeLock under-locked " + mTag); 784 } 785 } 786 } 787 788 /** 789 * Returns true if the wake lock has been acquired but not yet released. 790 * 791 * @return True if the wake lock is held. 792 */ 793 public boolean isHeld() { 794 synchronized (mToken) { 795 return mHeld; 796 } 797 } 798 799 /** 800 * Sets the work source associated with the wake lock. 801 * <p> 802 * The work source is used to determine on behalf of which application 803 * the wake lock is being held. This is useful in the case where a 804 * service is performing work on behalf of an application so that the 805 * cost of that work can be accounted to the application. 806 * </p> 807 * 808 * @param ws The work source, or null if none. 809 */ 810 public void setWorkSource(WorkSource ws) { 811 synchronized (mToken) { 812 if (ws != null && ws.size() == 0) { 813 ws = null; 814 } 815 816 final boolean changed; 817 if (ws == null) { 818 changed = mWorkSource != null; 819 mWorkSource = null; 820 } else if (mWorkSource == null) { 821 changed = true; 822 mWorkSource = new WorkSource(ws); 823 } else { 824 changed = mWorkSource.diff(ws); 825 if (changed) { 826 mWorkSource.set(ws); 827 } 828 } 829 830 if (changed && mHeld) { 831 try { 832 mService.updateWakeLockWorkSource(mToken, mWorkSource); 833 } catch (RemoteException e) { 834 } 835 } 836 } 837 } 838 839 /** @hide */ 840 public void setTag(String tag) { 841 mTag = tag; 842 } 843 844 /** @hide */ 845 public void setUnimportantForLogging(boolean state) { 846 if (state) mFlags |= UNIMPORTANT_FOR_LOGGING; 847 else mFlags &= ~UNIMPORTANT_FOR_LOGGING; 848 } 849 850 @Override 851 public String toString() { 852 synchronized (mToken) { 853 return "WakeLock{" 854 + Integer.toHexString(System.identityHashCode(this)) 855 + " held=" + mHeld + ", refCount=" + mCount + "}"; 856 } 857 } 858 } 859} 860