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程序员Android 力荐 ，Android 开发者需要的必备技能
电量优化一直是Android 开发中的头等问题。本篇将分析一下Android M 以上电量优化措施电量优化相关的部分知识点。
注：文章参考MTK手机解决方案文档
通过本篇文章阅读，你将收获以下知识点:
1.Doze 模式
2.空闲状态下，优化app耗电
3.Doze 模式下的限制措施
4.Doze 模式概要
5.Doze 模式涉及的类如下:
6.Doze 模式状态
7.Doze 白名单
8.Doze 模式测试方法
9.开启Doze dubug 调试开关
1.Doze 模式
当设备处于非充电、灭屏状态下静止一段时间，设备将进入睡眠状态，进入Doze模式，延长电池使用时间。Doze 模式下系统会定期恢复正常操作，异步执行app的一些同步数据等操作。比如很长时间不使用，系统会允许设备一天访问一次网络等。当设备处于充电状态下，系统将进入标准模式，app执行操作将不被限制。
2.空闲状态下，优化app耗电
在用户没有使用app的情况下，系统会使app处于idle 状态,
在空闲状态下，系统将会禁止app 网络访问以及数据同步
3.Doze 模式下的限制措施
1.禁止网络访问
2.忽略Wake lock
3.忽略Alarms(setAlarmClock() 、AlarmManager.setAndAllowwhileIdle() 这两个方法除外)
4.忽略 WIFI 扫描
5.同步作业调度程序将不被执行
4.Doze 模式概要
5.Doze 模式涉及的类如下:
frameworks/base/services/core/java/com/android/server/DeviceIdleController.java
/**
* Keeps track of device idleness and drives low power mode based on that.
*/
public class DeviceIdleController extends SystemService
implements AnyMotionDetector.DeviceIdleCallback {
6. Doze 模式状态
- ACTIVE：手机设备处于激活活动状态
- INACTIVE：屏幕关闭进入非活动状态
- IDLE_PENDING：每隔30分钟让App进入等待空闲预备状态
- IDLE：空闲状态
- IDLE_MAINTENANCE：处理挂起任务
对应的 Doze 模式状态如下：
active---> inactive ---> idle_pending
运动模式检测
void handleMotionDetectedLocked(long timeout, String type) {
// The device is not yet active, so we want to go back to the pending idle
// state to wait again for no motion. Note that we only monitor for motion
// after moving out of the inactive state, so no need to worry about that.
boolean becomeInactive = false;
if (mState != STATE_ACTIVE) {
scheduleReportActiveLocked(type, Process.myUid());
mState = STATE_ACTIVE;
mInactiveTimeout = timeout;
mCurIdleBudget = 0;
mMaintenanceStartTime = 0;
EventLogTags.writeDeviceIdle(mState, type);
addEvent(EVENT_NORMAL);
becomeInactive = true;
}
if (mLightState == LIGHT_STATE_OVERRIDE) {
// We went out of light idle mode because we had started deep idle mode... let's
// now go back and reset things so we resume light idling if appropriate.
mLightState = STATE_ACTIVE;
EventLogTags.writeDeviceIdleLight(mLightState, type);
becomeInactive = true;
}
if (becomeInactive) {
becomeInactiveIfAppropriateLocked();
}
}
idle_pending ————>sensing
@Override
public void onAnyMotionResult(int result) {
if (DEBUG) Slog.d(TAG, "onAnyMotionResult(" + result + ")");
if (result != AnyMotionDetector.RESULT_UNKNOWN) {
synchronized (this) {
cancelSensingTimeoutAlarmLocked();
}
}
if (result == AnyMotionDetector.RESULT_MOVED) {
if (DEBUG) Slog.d(TAG, "RESULT_MOVED received.");
synchronized (this) {
handleMotionDetectedLocked(mConstants.INACTIVE_TIMEOUT, "sense_motion");
}
} else if (result == AnyMotionDetector.RESULT_STATIONARY) {
if (DEBUG) Slog.d(TAG, "RESULT_STATIONARY received.");
if (mState == STATE_SENSING) {
// If we are currently sensing, it is time to move to locating.
synchronized (this) {
mNotMoving = true;
stepIdleStateLocked("s:stationary");
}
} else if (mState == STATE_LOCATING) {
// If we are currently locating, note that we are not moving and step
// if we have located the position.
synchronized (this) {
mNotMoving = true;
if (mLocated) {
stepIdleStateLocked("s:stationary");
}
}
}
}
}
电量优化白名单
设置 --电池 --电量优化（menu菜单）
会设置查看app 电池优化使用情况
白名单是以xml形式存储(deviceidle.xml)
查看白名单命令
//主要存放app包名
adb shell dumpsys deviceidle whitelist
白名单代码保存部分代码如下
/**
* Package names the system has white-listed to opt out of power save restrictions,
* except for device idle mode.
*/
private final ArrayMap<String, Integer> mPowerSaveWhitelistAppsExceptIdle = new ArrayMap<>();
/**
* Package names the system has white-listed to opt out of power save restrictions for
* all modes.
*/
private final ArrayMap<String, Integer> mPowerSaveWhitelistApps = new ArrayMap<>();
/**
* Package names the user has white-listed to opt out of power save restrictions.
*/
private final ArrayMap<String, Integer> mPowerSaveWhitelistUserApps = new ArrayMap<>();
/**
* App IDs of built-in system apps that have been white-listed except for idle modes.
*/
private final SparseBooleanArray mPowerSaveWhitelistSystemAppIdsExceptIdle
= new SparseBooleanArray();
/**
* App IDs of built-in system apps that have been white-listed.
*/
private final SparseBooleanArray mPowerSaveWhitelistSystemAppIds = new SparseBooleanArray();
/**
* App IDs that have been white-listed to opt out of power save restrictions, except
* for device idle modes.
*/
private final SparseBooleanArray mPowerSaveWhitelistExceptIdleAppIds = new SparseBooleanArray();
/**
* Current app IDs that are in the complete power save white list, but shouldn't be
* excluded from idle modes. This array can be shared with others because it will not be
* modified once set.
*/
private int[] mPowerSaveWhitelistExceptIdleAppIdArray = new int[0];
/**
* App IDs that have been white-listed to opt out of power save restrictions.
*/
private final SparseBooleanArray mPowerSaveWhitelistAllAppIds = new SparseBooleanArray();
/**
* Current app IDs that are in the complete power save white list. This array can
* be shared with others because it will not be modified once set.
*/
private int[] mPowerSaveWhitelistAllAppIdArray = new int[0];
/**
* App IDs that have been white-listed by the user to opt out of power save restrictions.
*/
private final SparseBooleanArray mPowerSaveWhitelistUserAppIds = new SparseBooleanArray();
/**
* Current app IDs that are in the user power save white list. This array can
* be shared with others because it will not be modified once set.
*/
private int[] mPowerSaveWhitelistUserAppIdArray = new int[0];
8. Doze 模式测试方法
1.开启Doze adb shell dumpsys deviceidle enable// or MTK addadb shell setprop persist.config.AutoPowerModes 1
2.拔掉电池adb shell dumpsys battery unplug
3.调试Doze状态
Active ---idle_pending---sensing--location---idle --idle_mantenance
adb shell dumpsys deviceidle step
4.Dump Doze 状态分析
Doze 模式下的信息，包括电池电量优化白名单等adb shell dumpsys deviceidle
9. 开启Doze dubug 调试开关
默认false 关闭，设置为true 开启DeviceIdleController.java private static final boolean DEBUG = false;
至此，本篇已结束，如有不对的地方，欢迎您的建议与指正。同时期待您的关注，感谢您的阅读，谢谢！
