DisplayManagerService启动及主屏添加-Android13

1、DisplayManagerService启动

1.1 简要时序图

代码位置：frameworks/base/services/core/java/com/android/server/display
frameworks/native/services/displayservice
frameworks/native/services/surfaceflinger

1、多屏幕相关：DisplayDeviceRepository.java、LogicalDisplayMapper.java、LocalDisplayAdapter.java、DisplayEventReceiver.java

屏幕类型	静态屏幕标识符	相关类
本地	local:<stable-id>	LocalDisplayAdapter.java
网络	network:<mac-address>	WifiDisplayAdapter.java
虚拟	virtual:<package-name-and-name>	VirtualDisplayAdapter.java
叠加	overlay:<number>	OverlayDisplayAdapter.java，开发者选项中模拟辅助显示设备开启

2、屏幕亮度相关：BrightnessSynchronizer.java

2、DEFAULT_DISPLAY主屏幕添加

AOSP > 文档 > 核心主题 > 显示屏支持

在 Android 11 中， 启动期间报告的第一个屏幕是主屏幕。这与连接类型是内部还是外部并不相关。 不过，主屏幕是不能断开连接的，由此可见，实际操作中的主屏幕必须是内部屏幕。请注意，一些可折叠手机有多个内部屏幕。
辅助屏幕已正确分类为 Display.TYPE_INTERNAL 或 Display.TYPE_EXTERNAL（以前分别称为 Display.TYPE_BUILT_IN 和 Display.TYPE_HDMI），具体取决于连接类型。


在 Android 9 及更低版本中，屏幕使用 32 位 ID 表示，其中 0 表示内部屏幕，1 表示外部屏幕，[2, INT32_MAX] 表示 HWC 虚拟屏幕，而 -1 表示无效屏幕或非 HWC 虚拟屏幕。
从 Android 10 开始，屏幕会获得稳定持久的 ID，从而使 SurfaceFlinger 和 DisplayManagerService 可以跟踪两个以上的屏幕并识别以前看到的屏幕。如果 HWC 支持 IComposerClient.getDisplayIdentificationData 并提供屏幕标识数据，SurfaceFlinger 将会解析 EDID 结构并为物理屏幕和 HWC 虚拟屏幕分配稳定的 64 位屏幕 ID。系统会使用选项类型表示 ID，其中 null 值表示无效屏幕或非 HWC 虚拟屏幕。如果 HWC 不支持，SurfaceFlinger 会回退到最多只存在两个物理屏幕的旧版行为。

2.1 物理屏热插拔监听

1、启动注册 LocalDisplayAdapter.registerLocked 时查看添加 tryConnectDisplayLocked(physicalDisplayId)
2、DisplayEventReceiver 监听添加屏幕 tryConnectDisplayLocked(physicalDisplayId) ：

• DisplayEventListener监听注册流程 LocalDisplayAdapter.java#mInjector.setDisplayEventListenerLocked(getHandler().getLooper(), new LocalDisplayEventListener()) > DisplayEventReceiver.java#nativeInit > android_view_DisplayEventReceiver.cpp::nativeInit > DisplayEventDispatcher.cpp::mReceiver > DisplayEventReceiver.cpp::mEventConnection > SurfaceFlinger.cpp::createDisplayEventConnection > Scheduler.cpp::createDisplayEventConnection > EventThread.cpp::createEventConnection > new EventThreadConnection
• DisplayEventReceiver监听接受流程 HWC::onHotplug > SurfaceFlinger.cpp::dispatchDisplayHotplugEvent > Scheduler.cpp::onHotplugReceived > EventThread.cpp::onHotplugReceived > EventThread::threadMain > EventThread::dispatchEvent > EventThreadConnection::postEvent > DisplayEventReceiver.cpp::sendEvents > gui::BitTube::sendObjects(dataChannel, events, count) > ==LooperCallback== DisplayEventDispatcher.cpp::handleEvent > DisplayEventDispatcher::processPendingEvents > android_view_DisplayEventReceiver.cpp::NativeDisplayEventReceiver::dispatchHotplug > LocalDisplayAdapter.java#ProxyDisplayEventReceiver#onHotplug > LocalDisplayEventListener#onHotplug > LocalDisplayAdapter.java#tryConnectDisplayLocked

frameworks/base/services/core/java/com/android/server/display/LocalDisplayAdapter.java

private void tryConnectDisplayLocked(long physicalDisplayId) {final IBinder displayToken =mSurfaceControlProxy.getPhysicalDisplayToken(physicalDisplayId);if (displayToken != null) {SurfaceControl.StaticDisplayInfo staticInfo =mSurfaceControlProxy.getStaticDisplayInfo(displayToken);if (staticInfo == null) {Slog.w(TAG, "No valid static info found for display device " + physicalDisplayId);return;}SurfaceControl.DynamicDisplayInfo dynamicInfo =mSurfaceControlProxy.getDynamicDisplayInfo(displayToken);if (dynamicInfo == null) {Slog.w(TAG, "No valid dynamic info found for display device " + physicalDisplayId);return;}if (dynamicInfo.supportedDisplayModes == null) {// There are no valid modes for this device, so we can't use itSlog.w(TAG, "No valid modes found for display device " + physicalDisplayId);return;}if (dynamicInfo.activeDisplayModeId < 0) {// There is no active mode, and for now we don't have the// policy to set one.Slog.w(TAG, "No valid active mode found for display device " + physicalDisplayId);return;}if (dynamicInfo.activeColorMode < 0) {// We failed to get the active color mode. We don't bail out here since on the next// configuration pass we'll go ahead and set it to whatever it was set to last (or// COLOR_MODE_NATIVE if this is the first configuration).Slog.w(TAG, "No valid active color mode for display device " + physicalDisplayId);dynamicInfo.activeColorMode = Display.COLOR_MODE_INVALID;}SurfaceControl.DesiredDisplayModeSpecs modeSpecs =mSurfaceControlProxy.getDesiredDisplayModeSpecs(displayToken);LocalDisplayDevice device = mDevices.get(physicalDisplayId);if (device == null) {// Display was added.final boolean isFirstDisplay = mDevices.size() == 0;device = new LocalDisplayDevice(displayToken, physicalDisplayId, staticInfo,dynamicInfo, modeSpecs, isFirstDisplay);mDevices.put(physicalDisplayId, device);sendDisplayDeviceEventLocked(device, DISPLAY_DEVICE_EVENT_ADDED);} else if (device.updateDisplayPropertiesLocked(staticInfo, dynamicInfo,modeSpecs)) {sendDisplayDeviceEventLocked(device, DISPLAY_DEVICE_EVENT_CHANGED);}} else {// The display is no longer available. Ignore the attempt to add it.// If it was connected but has already been disconnected, we'll get a// disconnect event that will remove it from mDevices.}
}

2.2 物理屏信息

硬件插入显示器 HWC::onHotplug ，依赖于 Hardware Composer API。设备制造商必须实现 IComposerClient 2.3 HIDL 接口 (android.hardware.graphics.composer@2.3::IComposerClient) 的 getDisplayIdentificationData 方法，或者针对较旧的 libhardware 实现情况实现相应的 hardware/hwcomposer2.h 函数

• sf 创建DisplayDevice：SurfaceFlinger::setupNewDisplayDeviceInternal
• DMS 创建DisplayDevice、DisplayDeviceInfo：tryConnectDisplayLocked、getDisplayDeviceInfoLocked()

frameworks/base/services/core/java/com/android/server/display/DisplayDevice.java
frameworks/base/services/core/java/com/android/server/display/DisplayDeviceInfo.java
frameworks/base/services/core/java/com/android/server/display/LogicalDisplay.java
frameworks/base/core/java/android/view/DisplayInfo.java

DisplayDevice.java	DisplayDeviceInfo.java
IBinder mDisplayToken	String name
String mUniqueId	String uniqueId
DisplayDeviceConfig mDisplayDeviceConfig	int width
int mCurrentLayerStack = -1	int height
int mCurrentFlags = 0	int modeId
int mCurrentOrientation = -1	int defaultModeId
Rect mCurrentLayerStackRect	Display.Mode[] supportedModes = Display.Mode.EMPTY_ARRAY
Rect mCurrentDisplayRect	int colorMode
Context mContext	int[] supportedColorModes = { Display.COLOR_MODE_DEFAULT }
Surface mCurrentSurface	Display.HdrCapabilities hdrCapabilities
DisplayDeviceInfo mDebugLastLoggedDeviceInfo	boolean allmSupported
	boolean gameContentTypeSupported
	int densityDpi
	float xDpi
	float yDpi
	long appVsyncOffsetNanos
	long presentationDeadlineNanos
	int flags
	DisplayCutout displayCutout
	RoundedCorners roundedCorners
	int touch
	int rotation = Surface.ROTATION_0
	int type
	DisplayAddress address
	DeviceProductInfo deviceProductInfo
	int state = Display.STATE_ON
	int ownerUid
	String ownerPackageName
	DisplayEventReceiver.FrameRateOverride[] frameRateOverrides = new DisplayEventReceiver.FrameRateOverride[0]
	float brightnessMinimum
	float brightnessMaximum
	float brightnessDefault
	int installOrientation = Surface.ROTATION_0

frameworks/native/libs/ui/include/ui/DisplayIdentification.h
frameworks/native/libs/ui/include/ui/DisplayId.h
frameworks/native/services/surfaceflinger/DisplayDevice.h
frameworks/native/services/surfaceflinger/CompositionEngine/include/compositionengine/DisplayCreationArgs.h
frameworks/native/libs/ui/include/ui/StaticDisplayInfo.h
frameworks/native/libs/ui/include/ui/DynamicDisplayInfo.h

DisplayIdentificationInfo	DisplayDeviceState	DisplayCreationArgs	DisplayDevice	StaticDisplayInfo	DynamicDisplayInfo
PhysicalDisplayId id	struct Physical	DisplayId id	constexpr static float sDefaultMinLumiance = 0.0	DisplayConnectionType connectionType = DisplayConnectionType::Internal	std::vector<ui::DisplayMode> supportedDisplayModes
std::string name	int32_t sequenceId = sNextSequenceId++	ui::Size pixels = ui::kInvalidSize	constexpr static float sDefaultMaxLumiance = 500.0	float density = 0.f	ui::DisplayModeId activeDisplayModeId
std::optional<DeviceProductInfo> deviceProductInfo	std::optional<Physical> physical	bool isSecure = false	const sp<SurfaceFlinger> mFlinger	bool secure = false	std::vector<ui::ColorMode> supportedColorModes
	sp<IGraphicBufferProducer> surface	Hwc2::PowerAdvisor* powerAdvisor = nullptr	HWComposer& mHwComposer	std::optional<DeviceProductInfo> deviceProductInfo
	ui::LayerStack layerStack	std::string name	const wp<IBinder> mDisplayToken	Rotation installOrientation = ROTATION_0	ui::ColorMode activeColorMode
	uint32_t flags = 0		const int32_t mSequenceId		HdrCapabilities hdrCapabilities
	Rect layerStackSpaceRect		const std::optional<ui::DisplayConnectionType> mConnectionType		bool autoLowLatencyModeSupported
	Rect orientedDisplaySpaceRect		const std::shared_ptr<compositionengine::Display> mCompositionDisplay		bool gameContentTypeSupported
	ui::Rotation orientation = ui::ROTATION_0		std::string mDisplayName		ui::DisplayModeId preferredBootDisplayMode
	uint32_t width = 0		std::string mActiveModeFPSTrace		std::optional<ui::DisplayMode> getActiveDisplayMode() const
	uint32_t height = 0		std::string mActiveModeFPSHwcTrace
	std::string displayName		const ui::Rotation mPhysicalOrientation
	bool isSecure = false		ui::Rotation mOrientation = ui::ROTATION_0
	static std::atomic<int32_t> sNextSequenceId		static ui::Transform::RotationFlags sPrimaryDisplayRotationFlags
			hardware::graphics::composer::hal::PowerMode mPowerMode = hardware::graphics::composer::hal::PowerMode::OFF
			DisplayModePtr mActiveMode
			std::optional<float> mStagedBrightness = std::nullopt
			float mBrightness = -1.f
			const DisplayModes mSupportedModes
			std::atomic<nsecs_t> mLastHwVsync = 0
			const bool mIsPrimary
			uint32_t mFlags = 0
			std::optional<DeviceProductInfo> mDeviceProductInfo
			std::vector<ui::Hdr> mOverrideHdrTypes
			std::shared_ptr<scheduler::RefreshRateConfigs> mRefreshRateConfigs
			std::unique_ptr<RefreshRateOverlay> mRefreshRateOverlay
			mutable std::mutex mActiveModeLock
			ActiveModeInfo mDesiredActiveMode GUARDED_BY(mActiveModeLock)
			TracedOrdinal<bool> mDesiredActiveModeChanged GUARDED_BY(mActiveModeLock) = {“DesiredActiveModeChanged”, false}
			ActiveModeInfo mUpcomingActiveMode GUARDED_BY(kMainThreadContext)

3、默认屏幕亮度

frameworks/base/core/java/com/android/internal/display/BrightnessSynchronizer.java

public void startSynchronizing() {if (mDisplayManager == null) {mDisplayManager = mContext.getSystemService(DisplayManager.class);}if (mBrightnessSyncObserver.isObserving()) {Slog.wtf(TAG, "Brightness sync observer requesting synchronization a second time.");return;}mLatestFloatBrightness = getScreenBrightnessFloat();mLatestIntBrightness = getScreenBrightnessInt();Slog.i(TAG, "Initial brightness readings: " + mLatestIntBrightness + "(int), "+ mLatestFloatBrightness + "(float)");if (!Float.isNaN(mLatestFloatBrightness)) {mPendingUpdate = new BrightnessUpdate(BrightnessUpdate.TYPE_FLOAT,mLatestFloatBrightness);} else if (mLatestIntBrightness != PowerManager.BRIGHTNESS_INVALID) {mPendingUpdate = new BrightnessUpdate(BrightnessUpdate.TYPE_INT,mLatestIntBrightness);} else {final float defaultBrightness = mContext.getResources().getFloat(com.android.internal.R.dimen.config_screenBrightnessSettingDefaultFloat);mPendingUpdate = new BrightnessUpdate(BrightnessUpdate.TYPE_FLOAT, defaultBrightness);Slog.i(TAG, "Setting initial brightness to default value of: " + defaultBrightness);}mBrightnessSyncObserver.startObserving();mHandler.sendEmptyMessageAtTime(MSG_RUN_UPDATE, mClock.uptimeMillis());
}