长按power键的流程&&PhoneWindowManager的nullpointexception导致system_server crash 导致系统重启

灰太狼 2022-05-23 12:12 274阅读 0赞

前面的事件派发过程就跳过了，从PhoneWindowManager开始说起

## 安全模式简述 ##

android平台，在长按power / menu键时会快速进入一个模式选择，部分定制的平台是直接进入安装模式，也可以定制成公司需要的一些特定功能模式，比如报警 ...

power 也属于全局的特殊按键，同样在PhoneWindowManager.java中被捕获处理。

## Power键(long)监听流程 ##

InputDispatcher.cpp 中InputDispatcher::notifyKey分发按键

**\[cpp\]** [view plain][] [copy][view plain]

1.  void InputDispatcher::notifyKey(const NotifyKeyArgs\* args) \{
2.  \#if DEBUG\_INBOUND\_EVENT\_DETAILS
3.  ALOGD("notifyKey - eventTime=%lld, deviceId=%d, source=0x%x, policyFlags=0x%x, action=0x%x, "
4.  "flags=0x%x, keyCode=0x%x, scanCode=0x%x, metaState=0x%x, downTime=%lld",
5.  args->eventTime, args->deviceId, args->source, args->policyFlags,
6.  args->action, args->flags, args->keyCode, args->scanCode,
7.  args->metaState, args->downTime);
8.  \#endif
9.  if (!validateKeyEvent(args->action)) \{
10. return;
11. \}
12. 
13. uint32\_t policyFlags = args->policyFlags;
14. int32\_t flags = args->flags;
15. int32\_t metaState = args->metaState;
16. if ((policyFlags & POLICY\_FLAG\_VIRTUAL) || (flags & AKEY\_EVENT\_FLAG\_VIRTUAL\_HARD\_KEY)) \{
17. policyFlags |= POLICY\_FLAG\_VIRTUAL;
18. flags |= AKEY\_EVENT\_FLAG\_VIRTUAL\_HARD\_KEY;
19. \}
20. if (policyFlags & POLICY\_FLAG\_FUNCTION) \{
21. metaState |= AMETA\_FUNCTION\_ON;
22. \}
23. 
24. policyFlags |= POLICY\_FLAG\_TRUSTED;
25. 
26. int32\_t keyCode = args->keyCode;
27. if (metaState & AMETA\_META\_ON && args->action == AKEY\_EVENT\_ACTION\_DOWN) \{
28. int32\_t newKeyCode = AKEYCODE\_UNKNOWN;
29. if (keyCode == AKEYCODE\_DEL) \{
30. newKeyCode = AKEYCODE\_BACK;
31. \} else if (keyCode == AKEYCODE\_ENTER) \{
32. newKeyCode = AKEYCODE\_HOME;
33. \}
34. if (newKeyCode != AKEYCODE\_UNKNOWN) \{
35. AutoMutex \_l(mLock);
36. struct KeyReplacement replacement = \{keyCode, args->deviceId\};
37. mReplacedKeys.add(replacement, newKeyCode);
38. keyCode = newKeyCode;
39. metaState &= ~AMETA\_META\_ON;
40. \}
41. \} else if (args->action == AKEY\_EVENT\_ACTION\_UP) \{
42. // In order to maintain a consistent stream of up and down events, check to see if the key
43. // going up is one we've replaced in a down event and haven't yet replaced in an up event,
44. // even if the modifier was released between the down and the up events.
45. AutoMutex \_l(mLock);
46. struct KeyReplacement replacement = \{keyCode, args->deviceId\};
47. ssize\_t index = mReplacedKeys.indexOfKey(replacement);
48. if (index >= 0) \{
49. keyCode = mReplacedKeys.valueAt(index);
50. mReplacedKeys.removeItemsAt(index);
51. metaState &= ~AMETA\_META\_ON;
52. \}
53. \}
54. 
55. KeyEvent event;
56. event.initialize(args->deviceId, args->source, args->action,
57. flags, keyCode, args->scanCode, metaState, 0,
58. args->downTime, args->eventTime);
59. 
60. mPolicy->interceptKeyBeforeQueueing(&event, /\*byref\*/ policyFlags);
61. 
62. bool needWake;
63. \{ // acquire lock
64. mLock.lock();
65. 
66. if (shouldSendKeyToInputFilterLocked(args)) \{
67. mLock.unlock();
68. 
69. policyFlags |= POLICY\_FLAG\_FILTERED;
70. if (!mPolicy->filterInputEvent(&event, policyFlags)) \{
71. return; // event was consumed by the filter
72. \}
73. 
74. mLock.lock();
75. \}
76. 
77. int32\_t repeatCount = 0;
78. KeyEntry\* newEntry = new KeyEntry(args->eventTime,
79. args->deviceId, args->source, policyFlags,
80. args->action, flags, keyCode, args->scanCode,
81. metaState, repeatCount, args->downTime);
82. 
83. needWake = enqueueInboundEventLocked(newEntry);
84. mLock.unlock();
85. \} // release lock
86. 
87. if (needWake) \{
88. mLooper->wake();
89. \}
90. \}

mPolicy->interceptKeyBeforeQueueing(&event, /\*byref\*/ policyFlags); 截获按键并处理，也即NativeInputManager::interceptKeyBeforeQueueing

**\[cpp\]** [view plain][] [copy][view plain]

1.  void NativeInputManager::interceptKeyBeforeQueueing(const KeyEvent\* keyEvent,
2.  uint32\_t& policyFlags) \{
3.  // Policy:
4.  // - Ignore untrusted events and pass them along.
5.  // - Ask the window manager what to do with normal events and trusted injected events.
6.  // - For normal events wake and brighten the screen if currently off or dim.
7.  if (mInteractive) \{
8.  policyFlags |= POLICY\_FLAG\_INTERACTIVE;
9.  \}
10. if ((policyFlags & POLICY\_FLAG\_TRUSTED)) \{
11. nsecs\_t when = keyEvent->getEventTime();
12. JNIEnv\* env = jniEnv();
13. jobject keyEventObj = android\_view\_KeyEvent\_fromNative(env, keyEvent);
14. jint wmActions;
15. if (keyEventObj) \{
16. wmActions = env->CallIntMethod(mServiceObj,
17. gServiceClassInfo.interceptKeyBeforeQueueing,
18. keyEventObj, policyFlags);
19. if (checkAndClearExceptionFromCallback(env, "interceptKeyBeforeQueueing")) \{
20. wmActions = 0;
21. \}
22. android\_view\_KeyEvent\_recycle(env, keyEventObj);
23. env->DeleteLocalRef(keyEventObj);
24. \} else \{
25. ALOGE("Failed to obtain key event object for interceptKeyBeforeQueueing.");
26. wmActions = 0;
27. \}
28. 
29. handleInterceptActions(wmActions, when, /\*byref\*/ policyFlags);
30. \} else \{
31. if (mInteractive) \{
32. policyFlags |= POLICY\_FLAG\_PASS\_TO\_USER;
33. \}
34. \}
35. \}

wmActions = env->CallIntMethod(mServiceObj,gServiceClassInfo.interceptKeyBeforeQueueing,keyEventObj, policyFlags);则会call 到

InputManagerService.java中的interceptKeyBeforeQueueing

**\[cpp\]** [view plain][] [copy][view plain]

1.  private long interceptKeyBeforeQueueing(InputWindowHandle focus,
2.  KeyEvent event, int policyFlags) \{
3.  return mWindowManagerCallbacks.interceptKeyBeforeQueueing(focus, event, policyFlags);
4.  \}

mWindowManagerCallbacks实际为InputMonitor

SystemServer.java 文件中startOtherServices调用inputManager.setWindowManagerCallbacks(wm.getInputMonitor())，给mWindowManagerCallbacks

赋值，而wm.getInputMonitor()获取的是InputMonitor， 所以mWindowManagerCallbacks.interceptKeyBeforeQueueing最后调用到InputMonitor:interceptKeyBeforeQueueing

InputMonitor.java文件中：

**\[cpp\]** [view plain][] [copy][view plain]

1.  public long interceptKeyBeforeQueueing(
2.  InputWindowHandle focus, KeyEvent event, int policyFlags) \{
3.  WindowState windowState = focus != null ? (WindowState) focus.windowState : null;
4.  return mService.mPolicy.interceptKeyBeforeDispatching(windowState, event, policyFlags);
5.  \}

而mService.mPolicy.interceptKeyBeforeQueueing则是WindowManagerService的按键策略机制mPolicy来继续捕获，

mPolicy = PolicyManager.makeNewWindowManager // mPolicy为 PhoneWindowManager

PhoneWindowManager::interceptKeyBeforeDispatching其中就会截获KeyEvent.KEYCODE\_POWER

**\[java\]** [view plain][] [copy][view plain]

1. public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags) \{
2. if (!mSystemBooted) \{
3. // If we have not yet booted, don't let key events do anything.
4. return 0;
5. \}
6. final boolean interactive = (policyFlags & FLAG\_INTERACTIVE) != 0;
7. final boolean down = event.getAction() == KeyEvent.ACTION\_DOWN;
8. final boolean canceled = event.isCanceled();
9. ......
10. // Handle special keys.
11. switch (keyCode) \{
12. case KeyEvent.KEYCODE\_VOLUME\_DOWN:
13. ......
14. case KeyEvent.KEYCODE\_POWER: \{
15. 
16. result &= ~ACTION\_PASS\_TO\_USER;
17. isWakeKey = false; // wake-up will be handled separately
18. if (down) \{
19. interceptPowerKeyDown(event, interactive);
20. \} else \{
21. interceptPowerKeyUp(event, interactive, canceled);
22. \}
23. break;
24. \}
25. \}
26. ......
27. return result;
28. \}

interceptKeyBeforeQueueing里面就会截获一些特设的按键，下面我们看power键的处理

down 表示一直为ACTION\_DOWN状态，就会call interceptPowerKeyDown使用mHandler发送一个MSG\_POWER\_LONG\_PRESS消息，而mHandler(PolicyHandler)

就会在handleMessage处理消息MSG\_POWER\_LONG\_PRESS

## POWER\_LONG\_PRESS的处理 ##

上面处理MSG\_POWER\_LONG\_PRESS消息时，powerLongPress

**\[java\]** [view plain][] [copy][view plain]

1. private void powerLongPress() \{
2. final int behavior = getResolvedLongPressOnPowerBehavior();
3. switch (behavior) \{
4. case LONG\_PRESS\_POWER\_NOTHING:
5. break;
6. case LONG\_PRESS\_POWER\_GLOBAL\_ACTIONS:
7. mPowerKeyHandled = true;
8. if (!performHapticFeedbackLw(null, HapticFeedbackConstants.LONG\_PRESS, false)) \{
9. performAuditoryFeedbackForAccessibilityIfNeed();
10. \}
11. showGlobalActionsInternal();
12. break;
13. case LONG\_PRESS\_POWER\_SHUT\_OFF:
14. case LONG\_PRESS\_POWER\_SHUT\_OFF\_NO\_CONFIRM:
15. mPowerKeyHandled = true;
16. performHapticFeedbackLw(null, HapticFeedbackConstants.LONG\_PRESS, false);
17. sendCloseSystemWindows(SYSTEM\_DIALOG\_REASON\_GLOBAL\_ACTIONS);
18. mWindowManagerFuncs.shutdown(behavior == LONG\_PRESS\_POWER\_SHUT\_OFF);
19. break;
20. \}
21. \}

showGlobalActionsInternal会构造GlobalActions对象并显示

**\[java\]** [view plain][] [copy][view plain]

1. void showGlobalActionsInternal() \{
2. sendCloseSystemWindows(SYSTEM\_DIALOG\_REASON\_GLOBAL\_ACTIONS);
3. if (mGlobalActions == null) \{
4. mGlobalActions = new GlobalActions(mContext, mWindowManagerFuncs);
5. \}
6. final boolean keyguardShowing = isKeyguardShowingAndNotOccluded();
7. mGlobalActions.showDialog(keyguardShowing, isDeviceProvisioned());
8. if (keyguardShowing) \{
9. // since it took two seconds of long press to bring this up,
10. // poke the wake lock so they have some time to see the dialog.
11. mPowerManager.userActivity(SystemClock.uptimeMillis(), false);
12. \}
13. \}

## GlobalActions对话框的显示 ##

GlobalActions主要是针对 “ 静音，重启，关机，飞行模式 ” 等全局按键的特殊快捷功能弹出的一些Dialog对话框。

接着上面mGlobalActions.showDialog，继续分析showDialog

**\[java\]** [view plain][] [copy][view plain]

1. public void showDialog(boolean keyguardShowing, boolean isDeviceProvisioned) \{
2. mKeyguardShowing = keyguardShowing;
3. mDeviceProvisioned = isDeviceProvisioned;
4. if (mDialog != null) \{
5. mDialog.dismiss();
6. mDialog = null;
7. // Show delayed, so that the dismiss of the previous dialog completes
8. mHandler.sendEmptyMessage(MESSAGE\_SHOW);
9. \} else \{
10. handleShow();
11. \}
12. \}

mHandler中处理MESSAGE\_SHOW消息

**\[java\]** [view plain][] [copy][view plain]

1. private Handler mHandler = new Handler() \{
2. public void handleMessage(Message msg) \{
3. switch (msg.what) \{
4. case MESSAGE\_DISMISS:
5. if (mDialog != null) \{
6. mDialog.dismiss();
7. mDialog = null;
8. \}
9. break;
10. case MESSAGE\_REFRESH:
11. refreshSilentMode();
12. mAdapter.notifyDataSetChanged();
13. break;
14. case MESSAGE\_SHOW:
15. handleShow();
16. break;
17. \}
18. \}
19. \}

handleShow主要是创建Dialog对话框并显示

**\[java\]** [view plain][] [copy][view plain]

1. private void handleShow() \{
2. awakenIfNecessary();
3. mDialog = createDialog();
4. prepareDialog();
5. 
6. // If we only have 1 item and it's a simple press action, just do this action.
7. if (mAdapter.getCount() == 1
8. && mAdapter.getItem(0) instanceof SinglePressAction
9. && !(mAdapter.getItem(0) instanceof LongPressAction)) \{
10. ((SinglePressAction) mAdapter.getItem(0)).onPress();
11. \} else \{
12. WindowManager.LayoutParams attrs = mDialog.getWindow().getAttributes();
13. attrs.setTitle("GlobalActions");
14. mDialog.getWindow().setAttributes(attrs);
15. mDialog.show();
16. mDialog.getWindow().getDecorView().setSystemUiVisibility(View.STATUS\_BAR\_DISABLE\_EXPAND);
17. \}
18. \}

其中createDialog 创建的GlobalActionsDialog对话框内容比较丰富，创建一些Action ( SilentModeToggleAction/SilentModeTriStateAction, ToggleAction,) 保存在mItems里面, 其实我们也可以发现关机行为处理的PowerAction(ToggleAction 行为)也被添加到mItems ArrayList中。

**\[java\]** [view plain][] [copy][view plain]

1. private GlobalActionsDialog createDialog() \{
2. // Simple toggle style if there's no vibrator, otherwise use a tri-state
3. if (!mHasVibrator) \{
4. mSilentModeAction = new SilentModeToggleAction();
5. \} else \{
6. mSilentModeAction = new SilentModeTriStateAction(mContext, mAudioManager, mHandler);
7. \}
8. mAirplaneModeOn = new ToggleAction(
9. R.drawable.ic\_lock\_airplane\_mode,
10. R.drawable.ic\_lock\_airplane\_mode\_off,
11. R.string.global\_actions\_toggle\_airplane\_mode,
12. R.string.global\_actions\_airplane\_mode\_on\_status,
13. R.string.global\_actions\_airplane\_mode\_off\_status) \{
14. 
15. void onToggle(boolean on) \{
16. if (mHasTelephony && Boolean.parseBoolean(
17. SystemProperties.get(TelephonyProperties.PROPERTY\_INECM\_MODE))) \{
18. mIsWaitingForEcmExit = true;
19. // Launch ECM exit dialog
20. Intent ecmDialogIntent =
21. new Intent(TelephonyIntents.ACTION\_SHOW\_NOTICE\_ECM\_BLOCK\_OTHERS, null);
22. ecmDialogIntent.addFlags(Intent.FLAG\_ACTIVITY\_NEW\_TASK);
23. mContext.startActivity(ecmDialogIntent);
24. \} else \{
25. changeAirplaneModeSystemSetting(on);
26. \}
27. \}
28. 
29. @Override
30. protected void changeStateFromPress(boolean buttonOn) \{
31. if (!mHasTelephony) return;
32. 
33. // In ECM mode airplane state cannot be changed
34. if (!(Boolean.parseBoolean(
35. SystemProperties.get(TelephonyProperties.PROPERTY\_INECM\_MODE)))) \{
36. mState = buttonOn ? State.TurningOn : State.TurningOff;
37. mAirplaneState = mState;
38. \}
39. \}
40. 
41. public boolean showDuringKeyguard() \{
42. return true;
43. \}
44. 
45. public boolean showBeforeProvisioning() \{
46. return false;
47. \}
48. \};
49. onAirplaneModeChanged();
50. 
51. mItems = new ArrayList<Action>();
52. String\[\] defaultActions = mContext.getResources().getStringArray(
53. com.android.internal.R.array.config\_globalActionsList);
54. 
55. ArraySet<String> addedKeys = new ArraySet<String>();
56. for (int i = 0; i < defaultActions.length; i++) \{
57. String actionKey = defaultActions\[i\];
58. if (addedKeys.contains(actionKey)) \{
59. // If we already have added this, don't add it again.
60. continue;
61. \}
62. if (GLOBAL\_ACTION\_KEY\_POWER.equals(actionKey)) \{
63. mItems.add(new PowerAction());
64. \} else if (GLOBAL\_ACTION\_KEY\_AIRPLANE.equals(actionKey)) \{
65. mItems.add(mAirplaneModeOn);
66. \} else if (GLOBAL\_ACTION\_KEY\_BUGREPORT.equals(actionKey)) \{
67. if (Settings.Global.getInt(mContext.getContentResolver(),
68. Settings.Global.BUGREPORT\_IN\_POWER\_MENU, 0) != 0 && isCurrentUserOwner()) \{
69. mItems.add(getBugReportAction());
70. \}
71. \} else if (GLOBAL\_ACTION\_KEY\_SILENT.equals(actionKey)) \{
72. if (mShowSilentToggle) \{
73. mItems.add(mSilentModeAction);
74. \}
75. \} else if (GLOBAL\_ACTION\_KEY\_USERS.equals(actionKey)) \{
76. if (SystemProperties.getBoolean("fw.power\_user\_switcher", false)) \{
77. addUsersToMenu(mItems);
78. \}
79. \} else if (GLOBAL\_ACTION\_KEY\_SETTINGS.equals(actionKey)) \{
80. mItems.add(getSettingsAction());
81. \} else if (GLOBAL\_ACTION\_KEY\_LOCKDOWN.equals(actionKey)) \{
82. mItems.add(getLockdownAction());
83. \} else \{
84. Log.e(TAG, "Invalid global action key " + actionKey);
85. \}
86. // Add here so we don't add more than one.
87. addedKeys.add(actionKey);
88. \}
89. 
90. mAdapter = new MyAdapter();
91. 
92. AlertParams params = new AlertParams(mContext);
93. params.mAdapter = mAdapter;
94. params.mOnClickListener = this;
95. params.mForceInverseBackground = true;
96. 
97. GlobalActionsDialog dialog = new GlobalActionsDialog(mContext, params);
98. dialog.setCanceledOnTouchOutside(false); // Handled by the custom class.
99. 
100. dialog.getListView().setItemsCanFocus(true);
101. dialog.getListView().setLongClickable(true);
102. dialog.getListView().setOnItemLongClickListener(
103. new AdapterView.OnItemLongClickListener() \{
104. @Override
105. public boolean onItemLongClick(AdapterView<?> parent, View view, int position,
106. long id) \{
107. final Action action = mAdapter.getItem(position);
108. if (action instanceof LongPressAction) \{
109. return ((LongPressAction) action).onLongPress();
110. \}
111. return false;
112. \}
113. \});
114. dialog.getWindow().setType(WindowManager.LayoutParams.TYPE\_KEYGUARD\_DIALOG);
115. 
116. dialog.setOnDismissListener(this);
117. 
118. return dialog;
119. \}

在创建GlobalActionsDialog后给各个view设置监听，setItemsCanFocus，setLongClickable，setOnItemLongClickListener，其中setOnItemLongClickListener

就是针对长按键的处理 ((LongPressAction) action).onLongPress()，如果不想处理power长按动作可以dialog.getListView().setOnItemLongClickListener(null)来到达要求。

**\[java\]** [view plain][] [copy][view plain]

1.  public boolean onLongPress() \{
2.  mWindowManagerFuncs.rebootSafeMode(true);
3.  return true;
4.  \}

而mWindowManagerFuncs有就是WindowManagerService，rebootSafeMode就会调到

**\[java\]** [view plain][] [copy][view plain]

1.  // Called by window manager policy. Not exposed externally.
2.  @Override
3.  public void rebootSafeMode(boolean confirm) \{
4.  ShutdownThread.rebootSafeMode(mContext, confirm);
5.  \}

## ShutdownThread进入安全模式 ##

WindowManagerService 调用rebootSafeMode之后，就转到ShutdownThread 线程来处理

**\[java\]** [view plain][] [copy][view plain]

1. public static void rebootSafeMode(final Context context, boolean confirm) \{
2. mReboot = true;
3. mRebootSafeMode = true;
4. mRebootReason = null;
5. shutdownInner(context, confirm);
6. \}
7. 
8. static void shutdownInner(final Context context, boolean confirm) \{
9. // ensure that only one thread is trying to power down.
10. // any additional calls are just returned
11. synchronized (sIsStartedGuard) \{
12. if (sIsStarted) \{
13. Log.d(TAG, "Request to shutdown already running, returning.");
14. return;
15. \}
16. \}
17. 
18. final int longPressBehavior = context.getResources().getInteger(
19. com.android.internal.R.integer.config\_longPressOnPowerBehavior);
20. final int resourceId = mRebootSafeMode
21. ? com.android.internal.R.string.reboot\_safemode\_confirm
22. : (longPressBehavior == 2
23. ? com.android.internal.R.string.shutdown\_confirm\_question
24. : com.android.internal.R.string.shutdown\_confirm);
25. 
26. Log.d(TAG, "Notifying thread to start shutdown longPressBehavior=" + longPressBehavior);
27. 
28. if (confirm) \{
29. final CloseDialogReceiver closer = new CloseDialogReceiver(context);
30. if (sConfirmDialog != null) \{
31. sConfirmDialog.dismiss();
32. \}
33. sConfirmDialog = new AlertDialog.Builder(context)
34. .setTitle(mRebootSafeMode
35. ? com.android.internal.R.string.reboot\_safemode\_title
36. : com.android.internal.R.string.power\_off)
37. .setMessage(resourceId)
38. .setPositiveButton(com.android.internal.R.string.yes, new DialogInterface.OnClickListener() \{
39. public void onClick(DialogInterface dialog, int which) \{
40. beginShutdownSequence(context);
41. \}
42. \})
43. .setNegativeButton(com.android.internal.R.string.no, null)
44. .create();
45. closer.dialog = sConfirmDialog;
46. sConfirmDialog.setOnDismissListener(closer);
47. sConfirmDialog.getWindow().setType(WindowManager.LayoutParams.TYPE\_KEYGUARD\_DIALOG);
48. sConfirmDialog.show();
49. \} else \{
50. beginShutdownSequence(context);
51. \}
52. \}

rebootSafeMode会接着调shutdownInner，最终beginShutdownSequence call pms电源管理服务来关机重启

**\[java\]** [view plain][] [copy][view plain]

1. private static void beginShutdownSequence(Context context) \{
2. synchronized (sIsStartedGuard) \{
3. if (sIsStarted) \{
4. Log.d(TAG, "Shutdown sequence already running, returning.");
5. return;
6. \}
7. sIsStarted = true;
8. \}
9. 
10. // throw up an indeterminate system dialog to indicate radio is
11. // shutting down.
12. ProgressDialog pd = new ProgressDialog(context);
13. pd.setTitle(context.getText(com.android.internal.R.string.power\_off));
14. pd.setMessage(context.getText(com.android.internal.R.string.shutdown\_progress));
15. pd.setIndeterminate(true);
16. pd.setCancelable(false);
17. pd.getWindow().setType(WindowManager.LayoutParams.TYPE\_KEYGUARD\_DIALOG);
18. 
19. pd.show();
20. 
21. sInstance.mContext = context;
22. sInstance.mPowerManager = (PowerManager)context.getSystemService(Context.POWER\_SERVICE);
23. 
24. // make sure we never fall asleep again
25. sInstance.mCpuWakeLock = null;
26. try \{
27. sInstance.mCpuWakeLock = sInstance.mPowerManager.newWakeLock(
28. PowerManager.PARTIAL\_WAKE\_LOCK, TAG + "-cpu");
29. sInstance.mCpuWakeLock.setReferenceCounted(false);
30. sInstance.mCpuWakeLock.acquire();
31. \} catch (SecurityException e) \{
32. Log.w(TAG, "No permission to acquire wake lock", e);
33. sInstance.mCpuWakeLock = null;
34. \}
35. 
36. // also make sure the screen stays on for better user experience
37. sInstance.mScreenWakeLock = null;
38. if (sInstance.mPowerManager.isScreenOn()) \{
39. try \{
40. sInstance.mScreenWakeLock = sInstance.mPowerManager.newWakeLock(
41. PowerManager.FULL\_WAKE\_LOCK, TAG + "-screen");
42. sInstance.mScreenWakeLock.setReferenceCounted(false);
43. sInstance.mScreenWakeLock.acquire();
44. \} catch (SecurityException e) \{
45. Log.w(TAG, "No permission to acquire wake lock", e);
46. sInstance.mScreenWakeLock = null;
47. \}
48. \}
49. 
50. // start the thread that initiates shutdown
51. sInstance.mHandler = new Handler() \{
52. \};
53. sInstance.start();
54. \}

至此整个长按 power键的处理流程结束。

上面的文章转自：[https://blog.csdn.net/kehyuanyu/article/details/46697733\#comments][https_blog.csdn.net_kehyuanyu_article_details_46697733_comments]

\----------------------------------------------------------------------------------------------------------------------

就是在GlobalActions\#handleShow()中弹出的dialog。该类主要帮助PhoneWindowManager处理一些全局事件，如：power键的单击或者长按，静音模式处理，飞行模式处理和唤醒屏保的处理。

PhoneWindowManager不是一个独立binder通信的类，而是附属于WindowManagerService的一个类，处理跟PhoneWindowManager有关的事务。所以PhoneWindowManager是运行在与WindowManagerService同一个进程的，就是SystemServer进程，这个进程如果crash或者锁住了，那么系统将会重启，所以如果在修改PhoneWindManager相关的代码，一定要谨慎，因为系统的代码的逻辑是很复杂的，都是非常经过谨慎设计和测试的，所以修改尽量小，考虑清楚。

像在8735中加入弹出自定义窗口的代码就引起了空指针异常而导致了system\_server进程crash，最终导致重启。

private void handleShow() {
 //YYD-zhangjinbiao-add-20171225 for shutdown dialog
 if(sendShutdownBroadcast(mContext) ){//RS2.0
 
 return;
 }
 //YYD-zhangjinbiao-add-20171225 for shutdown dialog
 awakenIfNecessary();
 mDialog = createDialog();
 prepareDialog();
 
 // If we only have 1 item and it's a simple press action, just do this action.
 if (mAdapter.getCount() == 1
 && mAdapter.getItem(0) instanceof SinglePressAction
 && !(mAdapter.getItem(0) instanceof LongPressAction)) {
 ((SinglePressAction) mAdapter.getItem(0)).onPress();
 } else {
 WindowManager.LayoutParams attrs = mDialog.getWindow().getAttributes();
 attrs.setTitle("GlobalActions");
 mDialog.getWindow().setAttributes(attrs);
 mDialog.show();
 mDialog.getWindow().getDecorView().setSystemUiVisibility(View.STATUS_BAR_DISABLE_EXPAND);
 }
 }
 //YYD-zhangjinbiao-add-20171225 for shutdown dialog
 private boolean sendShutdownBroadcast(Context context){
 
 
 if("YX20C".equals(android.os.Build.MODEL)){
 
 return false ;
 }
 
 
 if(hasShutdownBroadcastAction(context)){
 
 Intent broadcast = new Intent("com.yongyida.robot.LONG_PRESS_POWER") ;
 context.sendBroadcast(broadcast);
 
 return true ;
 }
 
 return false ;
 }
 
 private boolean hasShutdownBroadcastAction(Context context){
 
 android.content.pm.PackageManager pm = context.getPackageManager();
 Intent broadcast = new Intent("com.yongyida.robot.LONG_PRESS_POWER") ;
 List<android.content.pm.ResolveInfo> ris = pm.queryBroadcastReceivers(broadcast, 0) ;
 
 return ris.size() > 0;
 }
 //YYD-zhangjinbiao-add-20171225 for shutdown dialog
 /**
 * Create the global actions dialog.
 * @return A new dialog.
 */
 private GlobalActionsDialog createDialog() {
 // Simple toggle style if there's no vibrator, otherwise use a tri-state
 if (!mHasVibrator) {
 mSilentModeAction = new SilentModeToggleAction();
 } else {
 mSilentModeAction = new SilentModeTriStateAction(mContext, mAudioManager, mHandler);
 }
 mAirplaneModeOn = new ToggleAction(
 R.drawable.ic_lock_airplane_mode,
 R.drawable.ic_lock_airplane_mode_off,
 R.string.global_actions_toggle_airplane_mode,
 R.string.global_actions_airplane_mode_on_status,
 R.string.global_actions_airplane_mode_off_status) {
 
 void onToggle(boolean on) {
 if (mHasTelephony && Boolean.parseBoolean(
 SystemProperties.get(TelephonyProperties.PROPERTY_INECM_MODE))) {
 mIsWaitingForEcmExit = true;
 // Launch ECM exit dialog
 Intent ecmDialogIntent =
 new Intent(TelephonyIntents.ACTION_SHOW_NOTICE_ECM_BLOCK_OTHERS, null);
 ecmDialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 mContext.startActivity(ecmDialogIntent);
 } else {
 changeAirplaneModeSystemSetting(on);
 }
 }
 
 @Override
 protected void changeStateFromPress(boolean buttonOn) {
 if (!mHasTelephony) return;
 
 // In ECM mode airplane state cannot be changed
 if (!(Boolean.parseBoolean(
 SystemProperties.get(TelephonyProperties.PROPERTY_INECM_MODE)))) {
 mState = buttonOn ? State.TurningOn : State.TurningOff;
 mAirplaneState = mState;
 }
 }
 
 public boolean showDuringKeyguard() {
 return true;
 }
 
 public boolean showBeforeProvisioning() {
 return false;
 }
 
 public boolean isEnabled() {
 boolean isAirplaneModeAvailable = true;
 //FIXME: for build pass, please help to crrect me
 /*try {
 final ITelephonyEx phoneEx = ITelephonyEx.Stub.asInterface(ServiceManager.checkService("phoneEx"));
 if (phoneEx != null) {
 isAirplaneModeAvailable = phoneEx.isAirplanemodeAvailableNow();
 }
 } catch (RemoteException e) {
 Log.d(TAG, "isAirplanemodeAvailableNow exception caught");
 }*/
 return (super.isEnabled() && isAirplaneModeAvailable);
 }
 };
 onAirplaneModeChanged();
 
 mItems = new ArrayList<Action>();
 String[] defaultActions = mContext.getResources().getStringArray(
 com.android.internal.R.array.config_globalActionsList);
 
 ArraySet<String> addedKeys = new ArraySet<String>();
 for (int i = 0; i < defaultActions.length; i++) {
 String actionKey = defaultActions[i];
 if (addedKeys.contains(actionKey)) {
 // If we already have added this, don't add it again.
 continue;
 }
 if (GLOBAL_ACTION_KEY_POWER.equals(actionKey)) {
 mItems.add(new PowerAction());
 } else if (GLOBAL_ACTION_KEY_AIRPLANE.equals(actionKey)) {
 //mItems.add(mAirplaneModeOn);
 } else if (GLOBAL_ACTION_KEY_BUGREPORT.equals(actionKey)) {
 if (Settings.Global.getInt(mContext.getContentResolver(),
 Settings.Global.BUGREPORT_IN_POWER_MENU, 0) != 0 && isCurrentUserOwner()) {
 //mItems.add(getBugReportAction());
 }
 } else if (GLOBAL_ACTION_KEY_SILENT.equals(actionKey)) {
 if (mShowSilentToggle) {
 //mItems.add(mSilentModeAction);
 }
 } else if (GLOBAL_ACTION_KEY_USERS.equals(actionKey)) {
 if (SystemProperties.getBoolean("fw.power_user_switcher", false)) {
 //addUsersToMenu(mItems);
 }
 } else if (GLOBAL_ACTION_KEY_SETTINGS.equals(actionKey)) {
 //mItems.add(getSettingsAction());
 } else if (GLOBAL_ACTION_KEY_LOCKDOWN.equals(actionKey)) {
 //mItems.add(getLockdownAction());
 } 
 	 //add by fox@wisky 2015.5.26
 else if (GLOBAL_ACTION_KEY_REBOOT.equals(actionKey)) {
 //mItems.add(new RebootAction());
 }
 //end
 
 	 else {
 Log.e(TAG, "Invalid global action key " + actionKey);
 }
 // Add here so we don't add more than one.
 addedKeys.add(actionKey);
 }
 
 mAdapter = new MyAdapter();
 
 AlertParams params = new AlertParams(mContext);
 params.mAdapter = mAdapter;
 params.mOnClickListener = this;
 params.mForceInverseBackground = true;
 
 GlobalActionsDialog dialog = new GlobalActionsDialog(mContext, params);
 dialog.setCanceledOnTouchOutside(false); // Handled by the custom class.
 
 dialog.getListView().setItemsCanFocus(true);
 dialog.getListView().setLongClickable(true);
 dialog.getListView().setOnItemLongClickListener(
 new AdapterView.OnItemLongClickListener() {
 @Override
 public boolean onItemLongClick(AdapterView<?> parent, View view, int position,
 long id) {
 final Action action = mAdapter.getItem(position);
 if (action instanceof LongPressAction) {
 return ((LongPressAction) action).onLongPress();
 }
 return false;
 }
 });
 dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
 
 dialog.setOnDismissListener(this);
 
 return dialog;
 }

在上面的修改中，就是在弹出自定义的关机窗口后，马上return，而不执行原来handleShow()的代码，然后因为handleShow（）中调用的createDialog（）方法初始化了mAirplaneModeOn = new ToggleAction(，在其他代码中引用了mAirplaneModeOn时，就报错了。使用MediatekLogView.bat打开mtklog\\aee\_exp\\db.fatal.00.JE\\db.fatal.00.JE.dbg,查看\_exp\_main.txt,报的是：

$\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* Fatal \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*$  
Build Info: 'L1.MP3:ALPS.L1.MP3.V2.3\_WISKY8735.3G.H\_P2:mt6735:S01,YYD/Y50B Pro/Y50B Pro:5.1/LMY47D/1527841396:user/test-keys'  
Flavor Info: 'None'  
Exception Log Time:\[Mon Jun 4 17:04:49 CST 2018\] \[362.208366\]  
  
Exception Class: Java (JE)  
Exception Type: system\_server\_crash  
  
Current Executing Process:  
system\_server  
  
  
Backtrace:  
Process: system\_server  
Build: YYD/Y50B Pro/Y50B Pro:5.1/LMY47D/1527841396:user/test-keys  
  
java.lang.NullPointerException: Attempt to invoke virtual method 'void com.android.internal.policy.impl.GlobalActions$ToggleAction.updateState(com.android.internal.policy.impl.GlobalActions$ToggleAction$State)' on a null object reference  
at com.android.internal.policy.impl.GlobalActions$8.onServiceStateChanged(GlobalActions.java:1136)  
at android.telephony.PhoneStateListener$1.handleMessage(PhoneStateListener.java:278)  
at android.os.Handler.dispatchMessage(Handler.java:111)  
at android.os.Looper.loop(Looper.java:194)  
at android.os.HandlerThread.run(HandlerThread.java:61)  
at com.android.server.ServiceThread.run(ServiceThread.java:46)

$\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* Fatal \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*\* \*\*$

[view plain]: https://blog.csdn.net/kehyuanyu/article/details/46697733#
[https_blog.csdn.net_kehyuanyu_article_details_46697733_comments]: https://blog.csdn.net/kehyuanyu/article/details/46697733#comments