前语
PowerManagerService之亮屏流程剖析 归纳了亮屏/灭屏的通用流程,PowerManagerService之手动灭屏 对手动灭屏流程进行了整体的剖析。 本文以前两篇文章为基础,来剖析主动灭屏,请读者必须仔细阅读前两篇文章。
主动灭屏
要想剖析主动灭屏,需得回顾下 PowerManagerService之亮屏流程剖析 的亮屏逻辑的一些细节。
在亮屏的时候,会保存亮屏的时刻,以及用户行为的时刻,这两个时刻用于决议用户行为,如下
// PowerManagerService.java
private void updateUserActivitySummaryLocked(long now, int dirty) {
// ...
for (int groupId : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
int groupUserActivitySummary = 0;
long groupNextTimeout = 0;
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId) != WAKEFULNESS_ASLEEP) {
final long lastUserActivityTime =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeLocked(groupId);
final long lastUserActivityTimeNoChangeLights =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeNoChangeLightsLocked(
groupId);
// mLastWakeTime 表明前次亮屏的时刻
// lastUserActivityTime 表明前次用户行为的时刻
if (lastUserActivityTime >= mLastWakeTime) {
// 核算使屏幕变暗的超时时刻
groupNextTimeout = lastUserActivityTime + screenOffTimeout - screenDimDuration;
if (now < groupNextTimeout) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_BRIGHT;
} else {
// ...
}
}
// ...
}
// ...
}
此刻得到的用户行为是 USER_ACTIVITY_SCREEN_BRIGHT,表明用户行为是要点亮屏幕。
之后会向 DisplayManagerService 建议恳求,而终究决议屏幕状况(亮、灭、暗,等等)的恳求战略,它的更新进程如下
int getDesiredScreenPolicyLocked(int groupId) {
final int wakefulness = mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId);
final int wakeLockSummary = mDisplayGroupPowerStateMapper.getWakeLockSummaryLocked(groupId);
if (wakefulness == WAKEFULNESS_ASLEEP || sQuiescent) {
// ...
} else if (wakefulness == WAKEFULNESS_DOZING) {
// ...
}
if (mIsVrModeEnabled) {
// ...
}
if ((wakeLockSummary & WAKE_LOCK_SCREEN_BRIGHT) != 0
|| !mBootCompleted
|| (mDisplayGroupPowerStateMapper.getUserActivitySummaryLocked(groupId)
& USER_ACTIVITY_SCREEN_BRIGHT) != 0
|| mScreenBrightnessBoostInProgress) {
return DisplayPowerRequest.POLICY_BRIGHT;
}
// ...
}
由于用户行为是 USER_ACTIVITY_SCREEN_BRIGHT,因而战略为 DisplayPowerRequest.POLICY_BRIGHT,它终究导致屏幕变亮。
那么亮屏后,是怎么主动灭屏呢?
// PowerManagerService.java
private void updateUserActivitySummaryLocked(long now, int dirty) {
// ...
for (int groupId : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
int groupUserActivitySummary = 0;
long groupNextTimeout = 0;
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId) != WAKEFULNESS_ASLEEP) {
final long lastUserActivityTime =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeLocked(groupId);
final long lastUserActivityTimeNoChangeLights =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeNoChangeLightsLocked(
groupId);
if (lastUserActivityTime >= mLastWakeTime) {
// 使屏幕变暗的超时时刻
groupNextTimeout = lastUserActivityTime + screenOffTimeout - screenDimDuration;
if (now < groupNextTimeout) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_BRIGHT;
} else {
// ...
}
}
// ...
}
// 运用屏幕变暗的超时时刻,发送一个守时音讯来更新用户行为
if (hasUserActivitySummary && nextTimeout >= 0) {
scheduleUserInactivityTimeout(nextTimeout);
}
}
private void scheduleUserInactivityTimeout(long timeMs) {
final Message msg = mHandler.obtainMessage(MSG_USER_ACTIVITY_TIMEOUT);
msg.setAsynchronous(true);
// 使用超时时刻,发送一个守时音讯,更新用户行为
// 终究调用 handleUserActivityTimeout
mHandler.sendMessageAtTime(msg, timeMs);
}
private void handleUserActivityTimeout() { // runs on handler thread
synchronized (mLock) {
// 标记用户行为需求更新
mDirty |= DIRTY_USER_ACTIVITY;
// 从头更新电源状况,其实便是为了更新用户行为
updatePowerStateLocked();
}
}
从上面的代码逻辑能够看出,当 Power 键亮屏后,会核算出使屏幕变暗的超时时刻,然后使用这个超时时刻,发送了一个守时音讯,当屏幕变暗的超时时刻到了,就会再次更新用户行为,如下
// PowerManagerService.java
private void updateUserActivitySummaryLocked(long now, int dirty) {
// ...
for (int groupId : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
int groupUserActivitySummary = 0;
long groupNextTimeout = 0;
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId) != WAKEFULNESS_ASLEEP) {
final long lastUserActivityTime =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeLocked(groupId);
final long lastUserActivityTimeNoChangeLights =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeNoChangeLightsLocked(
groupId);
if (lastUserActivityTime >= mLastWakeTime) {
groupNextTimeout = lastUserActivityTime + screenOffTimeout - screenDimDuration;
if (now < groupNextTimeout) {
// ...
} else {
// 核算灭屏的超时时刻
groupNextTimeout = lastUserActivityTime + screenOffTimeout;
if (now < groupNextTimeout) { // 进入 DIM 时刻段
// 更新用户行为
groupUserActivitySummary = USER_ACTIVITY_SCREEN_DIM;
}
}
}
// ...
}
// ...
// 运用灭屏的超时时刻,发送一个守时音讯来更新用户行为
if (hasUserActivitySummary && nextTimeout >= 0) {
scheduleUserInactivityTimeout(nextTimeout);
}
}
此次用户行为的更新,核算的是灭屏的超时时刻,然后用户行为更新为 USER_ACTIVITY_SCREEN_DIM,表明用户行为要使屏幕变暗。终究使用灭屏的超时时刻,发送了一个守时音讯来再次更新用户行为。
现在用户行为是使屏幕变暗,再看看恳求战略是怎么更新的
int getDesiredScreenPolicyLocked(int groupId) {
final int wakefulness = mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId);
final int wakeLockSummary = mDisplayGroupPowerStateMapper.getWakeLockSummaryLocked(groupId);
if (wakefulness == WAKEFULNESS_ASLEEP || sQuiescent) {
// ...
} else if (wakefulness == WAKEFULNESS_DOZING) {
// ...
}
if (mIsVrModeEnabled) {
// ...
}
if ((wakeLockSummary & WAKE_LOCK_SCREEN_BRIGHT) != 0
|| !mBootCompleted
|| (mDisplayGroupPowerStateMapper.getUserActivitySummaryLocked(groupId)
& USER_ACTIVITY_SCREEN_BRIGHT) != 0
|| mScreenBrightnessBoostInProgress) {
// ...
}
return DisplayPowerRequest.POLICY_DIM;
}
恳求战略更新为 DisplayPowerRequest.POLICY_DIM,终究它会使屏幕变暗。
当灭屏的超时时刻到了,咱们看下再次更新用户行为时,会产生什么
// PowerManagerService.java
private void updateUserActivitySummaryLocked(long now, int dirty) {
// ...
for (int groupId : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
int groupUserActivitySummary = 0;
long groupNextTimeout = 0;
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId) != WAKEFULNESS_ASLEEP) {
final long lastUserActivityTime =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeLocked(groupId);
final long lastUserActivityTimeNoChangeLights =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeNoChangeLightsLocked(
groupId);
if (lastUserActivityTime >= mLastWakeTime) {
groupNextTimeout = lastUserActivityTime + screenOffTimeout - screenDimDuration;
if (now < groupNextTimeout) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_BRIGHT;
} else {
groupNextTimeout = lastUserActivityTime + screenOffTimeout;
if (now < groupNextTimeout) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_DIM;
}
}
}
// 灭屏超时前,带有 PowerManager.ON_AFTER_RELEASE 这个flag的唤醒锁开释,延伸屏幕的亮/暗的时刻
if (groupUserActivitySummary == 0
&& lastUserActivityTimeNoChangeLights >= mLastWakeTime) {
// ...
}
// 灭屏超时,答应进入屏保
if (groupUserActivitySummary == 0) {
// ...
}
// 按键 KeyEvent.KEYCODE_SOFT_SLEEP 进入屏保
if (groupUserActivitySummary != USER_ACTIVITY_SCREEN_DREAM
&& userInactiveOverride) {
// ...
}
// 用 AttentionDetector 从头核算超时时刻,现在不剖析
if ((groupUserActivitySummary & USER_ACTIVITY_SCREEN_BRIGHT) != 0
&& (mDisplayGroupPowerStateMapper.getWakeLockSummaryLocked(groupId)
& WAKE_LOCK_STAY_AWAKE) == 0) {
// ...
}
// 确认是否有用户行为
hasUserActivitySummary |= groupUserActivitySummary != 0;
// 保存超时时刻
if (nextTimeout == -1) {
nextTimeout = groupNextTimeout;
} else if (groupNextTimeout != -1) {
nextTimeout = Math.min(nextTimeout, groupNextTimeout);
}
}
// DisplayGroupPowerStateMapper 保存用户行为
mDisplayGroupPowerStateMapper.setUserActivitySummaryLocked(groupId,
groupUserActivitySummary);
}
final long nextProfileTimeout = getNextProfileTimeoutLocked(now);
if (nextProfileTimeout > 0) {
nextTimeout = Math.min(nextTimeout, nextProfileTimeout);
}
// 使用超时时刻,发送一个守时音讯
if (hasUserActivitySummary && nextTimeout >= 0) {
scheduleUserInactivityTimeout(nextTimeout);
}
}
能够看到灭屏超时时刻到了时,有许多要素会再次影响用户行为和超时时刻,咱们疏忽这些要素,因而超时时刻和用户行为都为0。 已然没有了用户行为和超时时刻,那么天然不会发送守时音讯来更新用户行为了,由于立刻就要灭屏的嘛,就没必要去守时更新用户行为了。
此刻,我要提醒咱们,从亮屏到主动灭屏的进程中,此刻 wakefulness 仍是 WAKEFULNESS_AWAKE,现在立刻要灭屏了,因而需求再次更新 wakefulness,这便是更新电源状况进程中,updateWakefulnessLocked() 做的
// PowerManagerService.java
private boolean updateWakefulnessLocked(int dirty) {
boolean changed = false;
if ((dirty & (DIRTY_WAKE_LOCKS | DIRTY_USER_ACTIVITY | DIRTY_BOOT_COMPLETED
| DIRTY_WAKEFULNESS | DIRTY_STAY_ON | DIRTY_PROXIMITY_POSITIVE
| DIRTY_DOCK_STATE | DIRTY_ATTENTIVE | DIRTY_SETTINGS
| DIRTY_SCREEN_BRIGHTNESS_BOOST)) != 0) {
final long time = mClock.uptimeMillis();
for (int id : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(id) == WAKEFULNESS_AWAKE
&& isItBedTimeYetLocked(id)) {
if (isAttentiveTimeoutExpired(id, time)) {
// ... 不考虑 attentive timeout,大部分项目不支持 ...
} else if (shouldNapAtBedTimeLocked()) {
// ... 假如敞开了屏保,屏幕超时也会进入屏保 ...
} else {
// 更新 wakefulness 为 WAKEFULNESS_DOZING
changed = sleepDisplayGroupNoUpdateLocked(id, time,
PowerManager.GO_TO_SLEEP_REASON_TIMEOUT, 0, Process.SYSTEM_UID);
}
}
}
}
return changed;
}
private boolean isItBedTimeYetLocked(int groupId) {
if (!mBootCompleted) {
return false;
}
long now = mClock.uptimeMillis();
// 不考虑 attentive timeout,大部分项目不支持
if (isAttentiveTimeoutExpired(groupId, now)) {
return !isBeingKeptFromInattentiveSleepLocked(groupId);
} else {
return !isBeingKeptAwakeLocked(groupId);
}
}
private boolean isBeingKeptAwakeLocked(int groupId) {
return mStayOn // 开发者模式中是否翻开"充电常亮"功用
|| mProximityPositive // 是否间隔传感器坚持亮屏
|| (mDisplayGroupPowerStateMapper.getWakeLockSummaryLocked(groupId)
& WAKE_LOCK_STAY_AWAKE) != 0 // 是否有唤醒锁坚持亮屏
|| (mDisplayGroupPowerStateMapper.getUserActivitySummaryLocked(groupId) & (
USER_ACTIVITY_SCREEN_BRIGHT | USER_ACTIVITY_SCREEN_DIM)) != 0 // 是否有亮屏的用户行为
|| mScreenBrightnessBoostInProgress; // 屏幕是否在亮度增强的进程中
}
现在要进入灭屏,只要没有要素坚持屏幕长亮,那么就会更新 wakefulness 为 WAKEFULNESS_DOZING。
现在设备进入了打盹状况,打盹状况的流程不便是 PowerManagerService之手动灭屏 剖析过了吗? 假如设备进入打盹状况,而且能成功启动 doze dream,就会真实进入打盹状况,不然进入休眠状况。无论是设备进入打盹状况,仍是休眠状况,屏幕终究会灭。
主动灭屏小结
主动灭屏的原理便是使用核算出的超时时刻,发送一个守时音讯来更新用户行为,必要时更新 wakefulness,也便是更新体系状况,然后改变恳求的战略,终究改变了屏幕的状况(亮、灭、暗,等等)。
延伸亮屏时刻
现在咱们讨论一个与主动灭屏有关的论题,那便是延伸亮屏时刻
private void updateUserActivitySummaryLocked(long now, int dirty) {
// ...
for (int groupId : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
int groupUserActivitySummary = 0;
long groupNextTimeout = 0;
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId) != WAKEFULNESS_ASLEEP) {
final long lastUserActivityTime =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeLocked(groupId);
final long lastUserActivityTimeNoChangeLights =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeNoChangeLightsLocked(
groupId);
// 1. 主动灭屏前,用户接触TP,会导致用户行为时刻更新,然后延伸亮屏时刻
if (lastUserActivityTime >= mLastWakeTime) {
groupNextTimeout = lastUserActivityTime + screenOffTimeout - screenDimDuration;
if (now < groupNextTimeout) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_BRIGHT;
} else {
groupNextTimeout = lastUserActivityTime + screenOffTimeout;
if (now < groupNextTimeout) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_DIM;
}
}
}
// 2. 假如有更新用户行为时带有 PowerManager.USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS,那么也会延伸亮屏
if (groupUserActivitySummary == 0
&& lastUserActivityTimeNoChangeLights >= mLastWakeTime) {
// 依据 lastUserActivityTimeNoChangeLights 时刻点从头核算灭屏时刻
groupNextTimeout = lastUserActivityTimeNoChangeLights + screenOffTimeout;
if (now < groupNextTimeout) {
final DisplayPowerRequest displayPowerRequest =
mDisplayGroupPowerStateMapper.getPowerRequestLocked(groupId);
if (displayPowerRequest.policy == DisplayPowerRequest.POLICY_BRIGHT
|| displayPowerRequest.policy == DisplayPowerRequest.POLICY_VR) {
// 理论上讲,屏幕超时,屏幕会先变暗,但是这儿处理的为何是亮屏的恳求战略
// 这是由于,假如没有暗屏的时刻呢?
groupUserActivitySummary = USER_ACTIVITY_SCREEN_BRIGHT;
} else if (displayPowerRequest.policy == DisplayPowerRequest.POLICY_DIM) {
groupUserActivitySummary = USER_ACTIVITY_SCREEN_DIM;
}
}
}
}
mDisplayGroupPowerStateMapper.setUserActivitySummaryLocked(groupId,
groupUserActivitySummary);
}
// ...
if (hasUserActivitySummary && nextTimeout >= 0) {
scheduleUserInactivityTimeout(nextTimeout);
}
}
能够看到,有两种状况能够延伸亮屏的时刻
- 屏幕处于亮/暗时,假如用户接触TP,那么会更新更新用户行为时刻,然后导致延伸亮屏的时刻。特别地,假如屏幕处于暗屏状况,那么点击接触屏,会导致屏幕变亮。
- 假如有更新用户行为时带有 PowerManager.USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS,那么也会延伸亮屏。
本文剖析用户接触TP导致的延伸亮屏进程,别的一个请读者自行剖析。
当用户接触TP时,底层Input体系会经过JNI调用 PowerManagerService#userActivityFromNative()
// frameworks/base/services/core/jni/com_android_server_input_InputManagerService.cpp
void NativeInputManager::pokeUserActivity(nsecs_t eventTime, int32_t eventType) {
android_server_PowerManagerService_userActivity(eventTime, eventType);
}
// frameworks/base/services/core/jni/com_android_server_power_PowerManagerService.cpp
void android_server_PowerManagerService_userActivity(nsecs_t eventTime, int32_t eventType) {
if (gPowerManagerServiceObj) {
// 调用 Java 层的 PowerManagerService#userActivityFromNative()
env->CallVoidMethod(gPowerManagerServiceObj,
gPowerManagerServiceClassInfo.userActivityFromNative,
nanoseconds_to_milliseconds(eventTime), eventType, 0);
}
}
// PowerManagerService.java
private void userActivityFromNative(long eventTime, int event, int displayId, int flags) {
userActivityInternal(displayId, eventTime, event, flags, Process.SYSTEM_UID);
}
private void userActivityInternal(int displayId, long eventTime, int event, int flags,
int uid) {
synchronized (mLock) {
// ...
// 更新用户活动时刻
if (userActivityNoUpdateLocked(groupId, eventTime, event, flags, uid)) {
// 更新电源状况
updatePowerStateLocked();
}
}
}
原来用户接触TP,会更新用户行为的时刻,那么用户行为也会产生改变
private void updateUserActivitySummaryLocked(long now, int dirty) {
// ...
// 先移除更新用户行为的守时音讯
mHandler.removeMessages(MSG_USER_ACTIVITY_TIMEOUT);
// ...
for (int groupId : mDisplayGroupPowerStateMapper.getDisplayGroupIdsLocked()) {
int groupUserActivitySummary = 0;
long groupNextTimeout = 0;
if (mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId) != WAKEFULNESS_ASLEEP) {
final long lastUserActivityTime =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeLocked(groupId);
final long lastUserActivityTimeNoChangeLights =
mDisplayGroupPowerStateMapper.getLastUserActivityTimeNoChangeLightsLocked(
groupId);
// 用户接触TP,更新了用户行为时刻 lastUserActivityTime,因而这儿从头核算超时时刻
// 也便是说,延伸了亮屏的时刻
if (lastUserActivityTime >= mLastWakeTime) {
// 从头核算暗屏的超时时刻
groupNextTimeout = lastUserActivityTime + screenOffTimeout - screenDimDuration;
if (now < groupNextTimeout) {
// 用户行为是亮屏
groupUserActivitySummary = USER_ACTIVITY_SCREEN_BRIGHT;
} else {
// ...
}
}
}
// ...
// 再次发送守时音讯,更新用户行为
if (hasUserActivitySummary && nextTimeout >= 0) {
scheduleUserInactivityTimeout(nextTimeout);
}
}
由于用户行为时刻的更新,导致从头核算了暗屏的超时时刻,而且用户行为会更新为 USER_ACTIVITY_SCREEN_BRIGHT。
用户行为的更新,也导致了恳求战略的更新,如下
int getDesiredScreenPolicyLocked(int groupId) {
final int wakefulness = mDisplayGroupPowerStateMapper.getWakefulnessLocked(groupId);
final int wakeLockSummary = mDisplayGroupPowerStateMapper.getWakeLockSummaryLocked(groupId);
if (wakefulness == WAKEFULNESS_ASLEEP || sQuiescent) {
// ...
} else if (wakefulness == WAKEFULNESS_DOZING) {
// ...
}
if (mIsVrModeEnabled) {
// ...
}
if ((wakeLockSummary & WAKE_LOCK_SCREEN_BRIGHT) != 0
|| !mBootCompleted
|| (mDisplayGroupPowerStateMapper.getUserActivitySummaryLocked(groupId)
& USER_ACTIVITY_SCREEN_BRIGHT) != 0
|| mScreenBrightnessBoostInProgress) {
return DisplayPowerRequest.POLICY_BRIGHT;
}
// ...
}
能够看到,假如屏幕处于亮/暗状况,用户接触TP,恳求战略更新为 DisplayPowerRequest.POLICY_BRIGHT, 终究导致屏幕为亮屏状况。
别的,从头核算出的暗屏超时时刻,会被用来发送守时音讯来更新用户行为,因而就相当于重置了屏幕超时时刻。
因而,接触TP导致屏幕处于亮屏状况,而且重置了屏幕超时时刻,那么就相当于延伸了亮屏的时刻。
结束
假如明白了亮屏与灭屏的进程,主动灭屏的原理就没有那么复杂,假如读者在阅读本文时,发现许多东西讲的很简单,那是由于前面的文章已经剖析过,所以读者必须仔细阅读前面两篇文章。
以现在的三篇文章为根基,下一篇文章,咱们将讨论 PowerManagerService 的终究一个论题,唤醒锁。