Android4.0关机流程
1. 长摁电源键关机
ANDROID_ROOT/frameworks/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
2. 启动线程去关机
ANDROID_ROOT/frameworks/base/core/java/com/android/internal/app/ShutdownThread.java
3. 关机的实现,有的是用PowerManager来实现的，这里看到的是三星的代码
ANDROID_ROOT/base/core/java/android/os/Power.java
4. 找JNI看看是如何实现的
ANDROID_ROOT\frameworks\base\core\jni\android_os_Power.cpp
5. 看看android_reboot的引用
ANDROID_ROOT\system\core\include\cutils\android_reboot.h
6. 看看android_reboot的实现,详细的请看源码
ANDROID_ROOT\system\core\libcutils\android_reboot.c
7. 查看kernel关机接口
//暂时还是盲区
ANDROID_ROOT/frameworks/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
private void interceptPowerKeyDown(boolean handled) {
mPowerKeyHandled = handled;
if (!handled) {
mHandler.postDelayed(mPowerLongPress, ViewConfiguration.getGlobalActionKeyTimeout());
}
}
private final Runnable mPowerLongPress = new Runnable() {
public void run() {
// The context isn't read
if (mLongPressOnPowerBehavior < 0) {
mLongPressOnPowerBehavior = mContext.getResources().getInteger(
com.android.internal.R.integer.config_longPressOnPowerBehavior);
}
switch (mLongPressOnPowerBehavior) {
case LONG_PRESS_POWER_NOTHING:
break;
case LONG_PRESS_POWER_GLOBAL_ACTIONS:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
showGlobalActionsDialog();
break;
case LONG_PRESS_POWER_SHUT_OFF:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
ShutdownThread.shutdown(mContext, true); //启动关机线程去关机
break;
}
}
};
2. 启动线程去关机
ANDROID_ROOT/frameworks/base/core/java/com/android/internal/app/ShutdownThread.java
public static void shutdown(final Context context, boolean confirm) {
mReboot = false;
shutdownInner(context, confirm);
}
public static void shutdownInner(final Context context, boolean confirm) { //samsung yujing modify for reboot
// 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;
}
}
if (confirm) {
final CloseDialogReceiver closer = new CloseDialogReceiver(context);
final AlertDialog dialog = new AlertDialog.Builder(context)
.setTitle(mReboot?com.android.internal.R.string.global_action_reboot: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 = dialog;
dialog.setOnDismissListener(closer);
dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
dialog.show();
} else {
beginShutdownSequence(context); //不管如何，总会调到这个函数去关机
}
}
private static void beginShutdownSequence(Context context) {
SystemProperties.set("ctl.start","shutdownanim");
...
// start the thread that initiates shutdown
sInstance.mHandler = new Handler() {
};
sInstance.start();
}
//sInstance.run(){}
/**
* Makes sure we handle the shutdown gracefully.
* Shuts off power regardless of radio and bluetooth state if the alloted time has passed.
*/
public void run() {
...
/*
* 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") + (mRebootReason != null ? mRebootReason : "");
SystemProperties.set(SHUTDOWN_ACTION_PROPERTY, reason);
}
Log.i(TAG, "Sending shutdown broadcast...");
// First send the high-level shut down broadcast.
mActionDone = false;
mContext.sendOrderedBroadcast(new Intent(Intent.ACTION_SHUTDOWN), null,
br, mHandler, 0, null, null);
rebootOrShutdown(mReboot, mRebootReason);
}
/**
* Do not call this directly. Use {@link #reboot(Context, String, boolean)}
* or {@link #shutdown(Context, boolean)} instead.
*
* @param reboot true to reboot or false to shutdown
* @param reason reason for reboot
*/
public static void rebootOrShutdown(boolean reboot, String reason) {
if (reboot) {
Log.i(TAG, "Rebooting, reason: " + reason);
try {
Power.reboot(reason);
} catch (Exception e) {
Log.e(TAG, "Reboot failed, will attempt shutdown instead", e);
}
} else if (SHUTDOWN_VIBRATE_MS > 0) {
// vibrate before shutting down
Vibrator vibrator = new Vibrator();
try {
vibrator.vibrate(SHUTDOWN_VIBRATE_MS);
} 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...");
Power.shutdown(); //关机
}
3. 关机的实现,有的是用PowerManager来实现的，这里看到的是三星的代码
ANDROID_ROOT/base/core/java/android/os/Power.java
/**
* Low-level function turn the device off immediately, without trying
* to be clean. Most people should use
* {@link android.internal.app.ShutdownThread} for a clean shutdown.
*
* @deprecated
* @hide
*/
@Deprecated
public static native void shutdown();
4. 找JNI看看是如何实现的
ANDROID_ROOT\frameworks\base\core\jni\android_os_Power.cpp
static JNINativeMethod method_table[] = {
{ "acquireWakeLock", "(ILjava/lang/String;)V", (void*)acquireWakeLock },
{ "releaseWakeLock", "(Ljava/lang/String;)V", (void*)releaseWakeLock },
{ "setLastUserActivityTimeout", "(J)I", (void*)setLastUserActivityTimeout },
{ "setScreenState", "(Z)I", (void*)setScreenState },
{ "shutdown", "()V", (void*)android_os_Power_shutdown },
{ "rebootNative", "(Ljava/lang/String;)V", (void*)android_os_Power_reboot },
};
static void android_os_Power_shutdown(JNIEnv *env, jobject clazz)
{
android_reboot(ANDROID_RB_POWEROFF, 0, 0);
}
5. 看看android_reboot的引用
ANDROID_ROOT\system\core\include\cutils\android_reboot.h
#ifndef __CUTILS_ANDROID_REBOOT_H__ #define __CUTILS_ANDROID_REBOOT_H__ __BEGIN_DECLS /* Commands */ #define ANDROID_RB_RESTART 0xDEAD0001 #define ANDROID_RB_POWEROFF 0xDEAD0002 #define ANDROID_RB_RESTART2 0xDEAD0003 /* Flags */ #define ANDROID_RB_FLAG_NO_SYNC 0x1 #define ANDROID_RB_FLAG_NO_REMOUNT_RO 0x2 int android_reboot(int cmd, int flags, char *arg); __END_DECLS #endif /* __CUTILS_ANDROID_REBOOT_H__ */
6. 看看android_reboot的实现,详细的请看源码
ANDROID_ROOT\system\core\libcutils\android_reboot.c
int android_reboot(int cmd, int flags, char *arg)
{
int ret;
if (!(flags & ANDROID_RB_FLAG_NO_SYNC))
sync();
if (!(flags & ANDROID_RB_FLAG_NO_REMOUNT_RO))
remount_ro();
switch (cmd) {
case ANDROID_RB_RESTART:
ret = reboot(RB_AUTOBOOT);
break;
case ANDROID_RB_POWEROFF:
ret = reboot(RB_POWER_OFF); //系统调用，下一步就是去kernel查看了
break;
case ANDROID_RB_RESTART2:
ret = __reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
LINUX_REBOOT_CMD_RESTART2, arg);
break;
default:
ret = -1;
}
return ret;
}
7. 查看kernel关机接口
//暂时还是盲区