关机流程我们从按power键-到dialog弹出，再到ShutdownThread，一步一步来讲
一.按power键
大家都知道长按power键会弹出关机重启提示框，而按键的捕获都是在PhoneWindowManager.java中
PhoneWindowManager.java-->interceptPowerKeyDown()
private void interceptPowerKeyDown(KeyEvent event, boolean interactive) {
......
if (hasLongPressOnPowerBehavior()) {
if ((event.getFlags() & KeyEvent.FLAG_LONG_PRESS) != 0) {
powerLongPress();
} else {
Message msg = mHandler.obtainMessage(MSG_POWER_LONG_PRESS);
msg.setAsynchronous(true);
mHandler.sendMessageDelayed(msg,
ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());
if (hasVeryLongPressOnPowerBehavior()) {
Message longMsg = mHandler.obtainMessage(MSG_POWER_VERY_LONG_PRESS);
longMsg.setAsynchronous(true);
mHandler.sendMessageDelayed(longMsg, mVeryLongPressTimeout);
}
}
}
......
}如果是长按行为的话，就会触发powerLongPress()
PhoneWindowManager.java-->powerLongPress()
private void powerLongPress() {
final int behavior = getResolvedLongPressOnPowerBehavior();
switch (behavior) {
case LONG_PRESS_POWER_NOTHING:
break;
case LONG_PRESS_POWER_GLOBAL_ACTIONS:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
//弹出Dialog
showGlobalActionsInternal();
break;
case LONG_PRESS_POWER_SHUT_OFF:
case LONG_PRESS_POWER_SHUT_OFF_NO_CONFIRM:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
mWindowManagerFuncs.shutdown(behavior == LONG_PRESS_POWER_SHUT_OFF);
break;
case LONG_PRESS_POWER_GO_TO_VOICE_ASSIST:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
final boolean keyguardActive = mKeyguardDelegate == null
? false
: mKeyguardDelegate.isShowing();
if (!keyguardActive) {
Intent intent = new Intent(Intent.ACTION_VOICE_ASSIST);
if (mAllowStartActivityForLongPressOnPowerDuringSetup) {
mContext.startActivityAsUser(intent, UserHandle.CURRENT_OR_SELF);
} else {
startActivityAsUser(intent, UserHandle.CURRENT_OR_SELF);
}
}
break;
}
}二.弹出Dialog提示框
调用showGlobalActionsInternal()弹出关机重启对话框
PhoneWindowManager.java-->showGlobalActionsInternal()
void showGlobalActionsInternal() {
if (mGlobalActions == null) {
mGlobalActions = new GlobalActions(mContext, mWindowManagerFuncs);
}
final boolean keyguardShowing = isKeyguardShowingAndNotOccluded();
mGlobalActions.showDialog(keyguardShowing, isDeviceProvisioned());
if (keyguardShowing) {
// since it took two seconds of long press to bring this up,
// poke the wake lock so they have some time to see the dialog.
mPowerManager.userActivity(SystemClock.uptimeMillis(), false);
}
}
GlobalActions.java-->showDialog()
public void showDialog(boolean keyguardShowing, boolean deviceProvisioned) {
if (DEBUG) Slog.d(TAG, "showDialog " + keyguardShowing + " " + deviceProvisioned);
if (mGlobalActionsProvider != null && mGlobalActionsProvider.isGlobalActionsDisabled()) {
return;
}
mKeyguardShowing = keyguardShowing;
mDeviceProvisioned = deviceProvisioned;
mShowing = true;
// for bug#971773
if (mLegacyGlobalActions != null) {
try {
/*if (DEBUG)*/ Slog.d(TAG, "showDialog : dismiss the legacy dialog first!");
mLegacyGlobalActions.dismissDialog();
} catch (Exception e){}
}
if (mGlobalActionsAvailable) {
mHandler.postDelayed(mShowTimeout, 5000);
mGlobalActionsProvider.showGlobalActions();
} else {
// SysUI isn't alive, show legacy menu.
ensureLegacyCreated();
mLegacyGlobalActions.showDialog(mKeyguardShowing, mDeviceProvisioned);
}
}LegacyGlobalActions.java-->showDialog()
public void showDialog(boolean keyguardShowing, boolean isDeviceProvisioned) {
mKeyguardShowing = keyguardShowing;
mDeviceProvisioned = isDeviceProvisioned;
if (mDialog != null) {
mDialog.dismiss();
mDialog = null;
// Show delayed, so that the dismiss of the previous dialog completes
//SPRD: fix for bug 940751
mHandler.sendEmptyMessageDelayed(MESSAGE_SHOW, SHOW_DIALOG_DELAY);
} else {
handleShow();
}
}LegacyGlobalActions.java-->handleShow()
private void handleShow() {
/* SPRD: fix for bug 940751 @{ */
if(mHandler != null && mHandler.hasMessages(MESSAGE_SHOW)) {
Log.d(TAG, "delayed show dialog message.");
return;
}
/* @} */
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 {
if (mDialog != null) {
WindowManager.LayoutParams attrs = mDialog.getWindow().getAttributes();
attrs.setTitle("LegacyGlobalActions");
mDialog.getWindow().setAttributes(attrs);
mDialog.show();
mDialog.getWindow().getDecorView().setSystemUiVisibility(
View.STATUS_BAR_DISABLE_EXPAND);
}
}
}LegacyGlobalActions.java-->createDialog()
如果点击是关机，就会调用PowerAction
private ActionsDialog createDialog() {
......
if (GLOBAL_ACTION_KEY_POWER.equals(actionKey)) {
mItems.add(new PowerAction(mContext, mWindowManagerFuncs));
......
}下面看下PowerAction.java
public final class PowerAction extends SinglePressAction implements LongPressAction {
private final Context mContext;
private final WindowManagerPolicy.WindowManagerFuncs mWindowManagerFuncs;
......
//长按Power键重启
@Override
public boolean onLongPress() {
UserManager um = mContext.getSystemService(UserManager.class);
if (!um.hasUserRestriction(UserManager.DISALLOW_SAFE_BOOT)) {
mWindowManagerFuncs.rebootSafeMode(true);
return true;
}
return false;
}
......
//shutdown 关机
@Override
public void onPress() {
// shutdown by making sure radio and power are handled accordingly.
mWindowManagerFuncs.shutdown(false /* confirm */);
}
}
WindowManagerFuncs 是WindowManagerPolicy的一个内部接口，真正实现的地方是WindowManagerService.java
@Override
public void shutdown(boolean confirm) {
// Pass in the UI context, since ShutdownThread requires it (to show UI).
ShutdownThread.shutdown(ActivityThread.currentActivityThread().getSystemUiContext(),
PowerManager.SHUTDOWN_USER_REQUESTED, confirm);
}到这里就走到了关机的核心类：ShutdownThread.java
三.ShutdownThread.java分析
ShutdownThread.java-->shutdown()
public static void shutdown(final Context context, String reason, boolean confirm) {
mReboot = false;
mRebootSafeMode = false;
mReason = reason;
shutdownInner(context, confirm);
}ShutdownThread.java-->shutdownInner()
在这里会再次弹出一个确认框，防止误关机
private static void shutdownInner(final Context context, boolean confirm) {
// ShutdownThread is called from many places, so best to verify here that the context passed
// in is themed.
context.assertRuntimeOverlayThemable();
// ensure that only one thread is trying to power down.
// any additional calls are just returned
synchronized (sIsStartedGuard) {
if (sIsStarted) {
Log.d(TAG, "Request to shutdown already running, returning.");
return;
}
}
final int longPressBehavior = context.getResources().getInteger(
com.android.internal.R.integer.config_longPressOnPowerBehavior);
final int resourceId = mRebootSafeMode
? com.android.internal.R.string.reboot_safemode_confirm
/*UNISOC bug 908624,add confirm dialog.*/
: (mReboot
? com.android.internal.R.string.reboot_device_confirm
/*UNISOC bug 908624,add confirm dialog.*/
: (longPressBehavior == 2
? com.android.internal.R.string.shutdown_confirm_question
: com.android.internal.R.string.shutdown_confirm));
Log.d(TAG, "Notifying thread to start shutdown longPressBehavior=" + longPressBehavior);
//add by cyy end for QMobile ISU-2019-02246
if (confirm) {
final CloseDialogReceiver closer = new CloseDialogReceiver(context);
if (sConfirmDialog != null) {
sConfirmDialog.dismiss();
}
sConfirmDialog = new AlertDialog.Builder(context)
.setTitle(mRebootSafeMode
? com.android.internal.R.string.reboot_safemode_title
/*UNISOC bug 908624*/
:(mReboot
? com.android.internal.R.string.reboot_device_title
/*UNISOC bug 908624*/
: com.android.internal.R.string.power_off))
.setMessage(resourceId)
.setPositiveButton(com.android.internal.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
beginShutdownSequence(context);
}
})
.setNegativeButton(com.android.internal.R.string.no, null)
.create();
closer.dialog = sConfirmDialog;
sConfirmDialog.setOnDismissListener(closer);
sConfirmDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
sConfirmDialog.show();
} else {
beginShutdownSequence(context);
}
}
点击确认，进入到beginShutdownSequence()
private static void beginShutdownSequence(Context context) {
shutdownTime = SystemClock.elapsedRealtime() + MAX_SHUTDOWN_TIME;//add by chentong,shutdownanimation
synchronized (sIsStartedGuard) {
if (sIsStarted) {
Log.d(TAG, "Shutdown sequence already running, returning.");
return;
}
sIsStarted = true;
}
// 开始关机动画
if (shutdownAnim.hasShutdownAnimation() &&
!(mReason != null && mReason.startsWith(PowerManager.REBOOT_RECOVERY_UPDATE))) {
shutdownAnim.playShutdownAnimation();
} else {
sInstance.mProgressDialog = showShutdownDialog(context);
}
sInstance.mContext = context;
sInstance.mPowerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
//保持手机屏幕亮起状态
// make sure we never fall asleep again
sInstance.mCpuWakeLock = null;
try {
sInstance.mCpuWakeLock = sInstance.mPowerManager.newWakeLock(
PowerManager.PARTIAL_WAKE_LOCK, TAG + "-cpu");
sInstance.mCpuWakeLock.setReferenceCounted(false);
sInstance.mCpuWakeLock.acquire();
} catch (SecurityException e) {
Log.w(TAG, "No permission to acquire wake lock", e);
sInstance.mCpuWakeLock = null;
}
// also make sure the screen stays on for better user experience
sInstance.mScreenWakeLock = null;
if (sInstance.mPowerManager.isScreenOn()) {
try {
sInstance.mScreenWakeLock = sInstance.mPowerManager.newWakeLock(
PowerManager.FULL_WAKE_LOCK, TAG + "-screen");
sInstance.mScreenWakeLock.setReferenceCounted(false);
sInstance.mScreenWakeLock.acquire();
} catch (SecurityException e) {
Log.w(TAG, "No permission to acquire wake lock", e);
sInstance.mScreenWakeLock = null;
}
}
if (SecurityLog.isLoggingEnabled()) {
SecurityLog.writeEvent(SecurityLog.TAG_OS_SHUTDOWN);
}
// start the thread that initiates shutdown
if(sIsPowerOffAlarm){
Looper.prepare();
sInstance.mHandler = new Handler();
Log.d(TAG,">>> before start <<<");
sInstance.start();
Looper.loop();
}else{
sInstance.mHandler = new Handler() {
};
//通过start()调用run()方法
sInstance.start();
}
}在beginShutdownSequence()主要是开始播放关机动画，WakeLock.acquire()保持手机保持亮起状态，最后调用start()开启线程，所以就会走到run()方法里了
ShutdownThread.java-->run(),这里会关闭主要模块
在关机过程中需要关闭的各模块如下：
ActivityManagerService
PackageManagerService
Radio
发送关机广播
public void run() {
TimingsTraceLog shutdownTimingLog = newTimingsLog();
shutdownTimingLog.traceBegin("SystemServerShutdown");
metricShutdownStart();
metricStarted(METRIC_SYSTEM_SERVER);
BroadcastReceiver br = new BroadcastReceiver() {
@Override public void onReceive(Context context, Intent intent) {
// We don't allow apps to cancel this, so ignore the result.
actionDone();
}
};
/*
* Write a system property in case the system_server reboots before we
* get to the actual hardware restart. If that happens, we'll retry at
* the beginning of the SystemServer startup.
*/
{
String reason = (mReboot ? "1" : "0") + (mReason != null ? mReason : "");
SystemProperties.set(SHUTDOWN_ACTION_PROPERTY, reason);
}
/*
* If we are rebooting into safe mode, write a system property
* indicating so.
*/
if (mRebootSafeMode) {
SystemProperties.set(REBOOT_SAFEMODE_PROPERTY, "1");
}
metricStarted(METRIC_SEND_BROADCAST);
shutdownTimingLog.traceBegin("SendShutdownBroadcast");
Log.i(TAG, "Sending shutdown broadcast...");
// First send the high-level shut down broadcast.
//发送关机广播
mActionDone = false;
Intent intent = new Intent(Intent.ACTION_SHUTDOWN);
intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND | Intent.FLAG_RECEIVER_REGISTERED_ONLY);
mContext.sendOrderedBroadcastAsUser(intent,
UserHandle.ALL, null, br, mHandler, 0, null, null);
final long endTime = SystemClock.elapsedRealtime() + MAX_BROADCAST_TIME;
synchronized (mActionDoneSync) {
while (!mActionDone) {
long delay = endTime - SystemClock.elapsedRealtime();
if (delay <= 0) {
Log.w(TAG, "Shutdown broadcast timed out");
break;
} else if (mRebootHasProgressBar) {
int status = (int)((MAX_BROADCAST_TIME - delay) * 1.0 *
BROADCAST_STOP_PERCENT / MAX_BROADCAST_TIME);
sInstance.setRebootProgress(status, null);
}
try {
mActionDoneSync.wait(Math.min(delay, ACTION_DONE_POLL_WAIT_MS));
} catch (InterruptedException e) {
}
}
}
if (mRebootHasProgressBar) {
sInstance.setRebootProgress(BROADCAST_STOP_PERCENT, null);
}
shutdownTimingLog.traceEnd(); // SendShutdownBroadcast
metricEnded(METRIC_SEND_BROADCAST);
Log.i(TAG, "Shutting down activity manager...");
shutdownTimingLog.traceBegin("ShutdownActivityManager");
metricStarted(METRIC_AM);
final IActivityManager am =
IActivityManager.Stub.asInterface(ServiceManager.checkService("activity"));
if (am != null) {
try {
//关闭AMS
am.shutdown(MAX_BROADCAST_TIME);
} catch (RemoteException e) {
}
}
if (mRebootHasProgressBar) {
sInstance.setRebootProgress(ACTIVITY_MANAGER_STOP_PERCENT, null);
}
shutdownTimingLog.traceEnd();// ShutdownActivityManager
metricEnded(METRIC_AM);
Log.i(TAG, "Shutting down package manager...");
shutdownTimingLog.traceBegin("ShutdownPackageManager");
metricStarted(METRIC_PM);
final PackageManagerService pm = (PackageManagerService)
ServiceManager.getService("package");
if (pm != null) {
//关闭PMS
pm.shutdown();
}
if (mRebootHasProgressBar) {
sInstance.setRebootProgress(PACKAGE_MANAGER_STOP_PERCENT, null);
}
shutdownTimingLog.traceEnd(); // ShutdownPackageManager
metricEnded(METRIC_PM);
// 关闭radios.
shutdownTimingLog.traceBegin("ShutdownRadios");
metricStarted(METRIC_RADIOS);
shutdownRadios(MAX_RADIO_WAIT_TIME);
if (mRebootHasProgressBar) {
sInstance.setRebootProgress(RADIO_STOP_PERCENT, null);
}
shutdownTimingLog.traceEnd(); // ShutdownRadios
metricEnded(METRIC_RADIOS);
if (mRebootHasProgressBar) {
sInstance.setRebootProgress(MOUNT_SERVICE_STOP_PERCENT, null);
// If it's to reboot to install an update and uncrypt hasn't been
// done yet, trigger it now.
uncrypt();
}
shutdownTimingLog.traceEnd(); // SystemServerShutdown
metricEnded(METRIC_SYSTEM_SERVER);
saveMetrics(mReboot, mReason);
// SPRD:add for shutdownanim
shutdownAnim.waitForBootanim();
// Remaining work will be done by init, including vold shutdown
long shutdownDelay = shutdownTime - SystemClock.elapsedRealtime();
rebootOrShutdown(mContext, mReboot, mReason);
}然后调用rebootOrShutdown()
public static void rebootOrShutdown(final Context context, boolean reboot, String reason) {
if (reboot) {
Log.i(TAG, "Rebooting, reason: " + reason);
PowerManagerService.lowLevelReboot(reason);
Log.e(TAG, "Reboot failed, will attempt shutdown instead");
reason = null;
} else if (SHUTDOWN_VIBRATE_MS > 0 && context != null) {
// vibrate before shutting down
Vibrator vibrator = new SystemVibrator(context);
try {
//关机震动提示
vibrator.vibrate(SHUTDOWN_VIBRATE_MS, VIBRATION_ATTRIBUTES);
} catch (Exception e) {
// Failure to vibrate shouldn't interrupt shutdown. Just log it.
Log.w(TAG, "Failed to vibrate during shutdown.", e);
}
// vibrator is asynchronous so we need to wait to avoid shutting down too soon.
try {
Thread.sleep(SHUTDOWN_VIBRATE_MS);
} catch (InterruptedException unused) {
}
}
// Shutdown power
Log.i(TAG, "Performing low-level shutdown...");
PowerManagerService.lowLevelShutdown(reason);
}最后调用lowLevelShutdown()通过SystemProperties走到驱动层
public static void lowLevelShutdown(String reason) {
if (reason == null) {
reason = "";
}
SystemProperties.set("sys.powerctl", "shutdown," + reason);
}