Merge "Properly initialize MotionClassifier" (71f70d66) · Commits · e / os / android_frameworks_native-old

services/inputflinger/InputClassifier.cpp

+53 −81

Original line number	Diff line number	Diff line
		@@ -46,8 +46,6 @@ using namespace android::hardware::input;

		namespace android {

		static constexpr bool DEBUG = false;

		// Category (=namespace) name for the input settings that are applied at boot time
		static const char* INPUT_NATIVE_BOOT = "input_native_boot";
		// Feature flag name for the deep press feature
		@@ -141,53 +139,46 @@ std::optional<int32_t> ClassifierEvent::getDeviceId() const {

		// --- MotionClassifier ---

		MotionClassifier::MotionClassifier(sp<android::hardware::hidl_death_recipient> deathRecipient) :
		mDeathRecipient(deathRecipient), mEvents(MAX_EVENTS) {
		mHalThread = std::thread(&MotionClassifier::callInputClassifierHal, this);
		MotionClassifier::MotionClassifier(
		sp<android::hardware::input::classifier::V1_0::IInputClassifier> service)
		: mEvents(MAX_EVENTS), mService(service) {
		// Under normal operation, we do not need to reset the HAL here. But in the case where system
		// crashed, but HAL didn't, we may be connecting to an existing HAL process that might already
		// have received events in the past. That means, that HAL could be in an inconsistent state
		// once it receives events from the newly created MotionClassifier.
		mEvents.push(ClassifierEvent::createHalResetEvent());

		mHalThread = std::thread(&MotionClassifier::processEvents, this);
		#if defined(__linux__)
		// Set the thread name for debugging
		pthread_setname_np(mHalThread.native_handle(), "InputClassifier");
		#endif
		}

		/**
		* This function may block for some time to initialize the HAL, so it should only be called
		* from the "InputClassifier HAL" thread.
		*/
		bool MotionClassifier::init() {
		ensureHalThread(__func__);
		std::unique_ptr<MotionClassifierInterface> MotionClassifier::create(
		sp<android::hardware::hidl_death_recipient> deathRecipient) {
		if (!deepPressEnabled()) {
		// If feature is not enabled, MotionClassifier should stay null to avoid unnecessary work.
		// When MotionClassifier is null, InputClassifier will forward all events
		// to the next InputListener, unmodified.
		return nullptr;
		}
		sp<android::hardware::input::classifier::V1_0::IInputClassifier> service =
		classifier::V1_0::IInputClassifier::getService();
		if (!service) {
		// Not really an error, maybe the device does not have this HAL,
		// but somehow the feature flag is flipped
		ALOGI("Could not obtain InputClassifier HAL");
		return false;
		return nullptr;
		}

		sp<android::hardware::hidl_death_recipient> recipient = mDeathRecipient.promote();
		if (recipient != nullptr) {
		const bool linked = service->linkToDeath(recipient, 0 /* cookie */).withDefault(false);
		const bool linked = service->linkToDeath(deathRecipient, 0 /* cookie */).withDefault(false);
		if (!linked) {
		ALOGE("Could not link MotionClassifier to the HAL death");
		return false;
		}
		}

		// Under normal operation, we do not need to reset the HAL here. But in the case where system
		// crashed, but HAL didn't, we may be connecting to an existing HAL process that might already
		// have received events in the past. That means, that HAL could be in an inconsistent state
		// once it receives events from the newly created MotionClassifier.
		mEvents.push(ClassifierEvent::createHalResetEvent());

		{
		std::scoped_lock lock(mLock);
		if (mService) {
		ALOGE("MotionClassifier::%s should only be called once", __func__);
		ALOGE("Could not link death recipient to the HAL death");
		return nullptr;
		}
		mService = service;
		}
		return true;
		// Using 'new' to access a non-public constructor
		return std::unique_ptr<MotionClassifier>(new MotionClassifier(service));
		}

		MotionClassifier::~MotionClassifier() {
		@@ -195,14 +186,6 @@ MotionClassifier::~MotionClassifier() {
		mHalThread.join();
		}

		void MotionClassifier::ensureHalThread(const char* function) {
		if (DEBUG) {
		if (std::this_thread::get_id() != mHalThread.get_id()) {
		LOG_FATAL("Function %s should only be called from InputClassifier thread", function);
		}
		}
		}

		/**
		* Obtain the classification from the HAL for a given MotionEvent.
		* Should only be called from the InputClassifier thread (mHalThread).
		@@ -213,23 +196,7 @@ void MotionClassifier::ensureHalThread(const char* function) {
		* To remove any possibility of negatively affecting the touch latency, the HAL
		* is called from a dedicated thread.
		*/
		void MotionClassifier::callInputClassifierHal() {
		ensureHalThread(__func__);
		const bool initialized = init();
		if (!initialized) {
		// MotionClassifier no longer useful.
		// Deliver death notification from a separate thread
		// because ~MotionClassifier may be invoked, which calls mHalThread.join()
		std::thread([deathRecipient = mDeathRecipient](){
		sp<android::hardware::hidl_death_recipient> recipient = deathRecipient.promote();
		if (recipient != nullptr) {
		recipient->serviceDied(0 /cookie/, nullptr);
		}
		}).detach();
		return;
		}
		// From this point on, mService is guaranteed to be non-null.

		void MotionClassifier::processEvents() {
		while (true) {
		ClassifierEvent event = mEvents.pop();
		bool halResponseOk = true;
		@@ -383,24 +350,30 @@ void MotionClassifier::dump(std::string& dump) {
		}
		}

		// --- HalDeathRecipient

		// --- InputClassifier ---
		InputClassifier::HalDeathRecipient::HalDeathRecipient(InputClassifier& parent) : mParent(parent) {}

		InputClassifier::InputClassifier(const sp<InputListenerInterface>& listener) :
		mListener(listener) {
		// The rest of the initialization is done in onFirstRef, because we need to obtain
		// an sp to 'this' in order to register for HAL death notifications
		void InputClassifier::HalDeathRecipient::serviceDied(
		uint64_t cookie, const wp<android::hidl::base::V1_0::IBase>& who) {
		sp<android::hidl::base::V1_0::IBase> service = who.promote();
		if (service) {
		service->unlinkToDeath(this);
		}

		void InputClassifier::onFirstRef() {
		if (!deepPressEnabled()) {
		// If feature is not enabled, MotionClassifier should stay null to avoid unnecessary work.
		// When MotionClassifier is null, InputClassifier will forward all events
		// to the next InputListener, unmodified.
		return;
		mParent.setMotionClassifier(nullptr);
		}
		std::scoped_lock lock(mLock);
		mMotionClassifier = std::make_unique<MotionClassifier>(this);

		// --- InputClassifier ---

		InputClassifier::InputClassifier(const sp<InputListenerInterface>& listener)
		: mListener(listener), mHalDeathRecipient(new HalDeathRecipient(*this)) {
		mInitializeMotionClassifierThread = std::thread(
		[this] { setMotionClassifier(MotionClassifier::create(mHalDeathRecipient)); });
		#if defined(__linux__)
		// Set the thread name for debugging
		pthread_setname_np(mInitializeMotionClassifierThread.native_handle(),
		"Create MotionClassifier");
		#endif
		}

		void InputClassifier::notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) {
		@@ -441,15 +414,10 @@ void InputClassifier::notifyDeviceReset(const NotifyDeviceResetArgs* args) {
		mListener->notifyDeviceReset(args);
		}

		void InputClassifier::serviceDied(uint64_t /cookie/,
		const wp<android::hidl::base::V1_0::IBase>& who) {
		void InputClassifier::setMotionClassifier(
		std::unique_ptr<MotionClassifierInterface> motionClassifier) {
		std::scoped_lock lock(mLock);
		ALOGE("InputClassifier HAL has died. Setting mMotionClassifier to null");
		mMotionClassifier = nullptr;
		sp<android::hidl::base::V1_0::IBase> service = who.promote();
		if (service) {
		service->unlinkToDeath(this);
		}
		mMotionClassifier = std::move(motionClassifier);
		}

		void InputClassifier::dump(std::string& dump) {
		@@ -465,4 +433,8 @@ void InputClassifier::dump(std::string& dump) {
		dump += "\n";
		}

		InputClassifier::~InputClassifier() {
		mInitializeMotionClassifierThread.join();
		}

		} // namespace android

services/inputflinger/InputClassifier.h

+50 −38

Original line number	Diff line number	Diff line
		@@ -19,8 +19,8 @@

		#include <android-base/thread_annotations.h>
		#include <utils/RefBase.h>
		#include <unordered_map>
		#include <thread>
		#include <unordered_map>

		#include "BlockingQueue.h"
		#include "InputListener.h"
		@@ -113,23 +113,23 @@ protected:
		*/
		class MotionClassifier final : public MotionClassifierInterface {
		public:
		/**
		* The deathRecipient will be subscribed to the HAL death. If the death recipient
		* owns MotionClassifier and receives HAL death, it should delete its copy of it.
		* The callback serviceDied will also be sent if the MotionClassifier itself fails
		* to initialize. If the MotionClassifier fails to initialize, it is not useful, and
		* should be deleted.
		* If no death recipient is supplied, then the registration step will be skipped, so there will
		* be no listeners registered for the HAL death. This is useful for testing
		* MotionClassifier in isolation.
		/*
		* Create an instance of MotionClassifier.
		* The death recipient, if provided, will be subscribed to the HAL death.
		* The death recipient could be used to destroy MotionClassifier.
		*
		* This function should be called asynchronously, because getService takes a long time.
		*/
		explicit MotionClassifier(sp<android::hardware::hidl_death_recipient> deathRecipient = nullptr);
		static std::unique_ptr<MotionClassifierInterface> create(
		sp<android::hardware::hidl_death_recipient> deathRecipient);

		~MotionClassifier();

		/**
		* Classifies events asynchronously; that is, it doesn't block events on a classification,
		* but instead sends them over to the classifier HAL and after a classification is
		* determined, it then marks the next event it sees in the stream with it.
		* but instead sends them over to the classifier HAL. After a classification of a specific
		* event is determined, MotionClassifier then marks the next event in the stream with this
		* classification.
		*
		* Therefore, it is acceptable to have the classifications be delayed by 1-2 events
		* in a particular gesture.
		@@ -141,15 +141,9 @@ public:
		virtual void dump(std::string& dump) override;

		private:
		/**
		* Initialize MotionClassifier.
		* Return true if initializaion is successful.
		*/
		bool init();
		/**
		* Entity that will be notified of the HAL death (most likely InputClassifier).
		*/
		wp<android::hardware::hidl_death_recipient> mDeathRecipient;
		friend class MotionClassifierTest; // to create MotionClassifier with a test HAL implementation
		explicit MotionClassifier(
		sp<android::hardware::input::classifier::V1_0::IInputClassifier> service);

		// The events that need to be sent to the HAL.
		BlockingQueue<ClassifierEvent> mEvents;
		@@ -164,14 +158,9 @@ private:
		*/
		std::thread mHalThread;
		/**
		* Print an error message if the caller is not on the InputClassifier thread.
		* Caller must supply the name of the calling function as __func__
		*/
		void ensureHalThread(const char* function);
		/**
		* Call the InputClassifier HAL
		* Process events and call the InputClassifier HAL
		*/
		void callInputClassifierHal();
		void processEvents();
		/**
		* Access to the InputClassifier HAL. May be null if init() hasn't completed yet.
		* When init() successfully completes, mService is guaranteed to remain non-null and to not
		@@ -223,19 +212,15 @@ private:
		const char* getServiceStatus() REQUIRES(mLock);
		};


		/**
		* Implementation of the InputClassifierInterface.
		* Represents a separate stage of input processing. All of the input events go through this stage.
		* Acts as a passthrough for all input events except for motion events.
		* The events of motion type are sent to MotionClassifier.
		*/
		class InputClassifier : public InputClassifierInterface,
		public android::hardware::hidl_death_recipient {
		class InputClassifier : public InputClassifierInterface {
		public:
		explicit InputClassifier(const sp<InputListenerInterface>& listener);
		// Some of the constructor logic is finished in onFirstRef
		virtual void onFirstRef() override;

		virtual void notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) override;
		virtual void notifyKey(const NotifyKeyArgs* args) override;
		@@ -243,17 +228,44 @@ public:
		virtual void notifySwitch(const NotifySwitchArgs* args) override;
		virtual void notifyDeviceReset(const NotifyDeviceResetArgs* args) override;

		virtual void serviceDied(uint64_t cookie,
		const wp<android::hidl::base::V1_0::IBase>& who) override;

		virtual void dump(std::string& dump) override;

		~InputClassifier();

		private:
		// Protect access to mMotionClassifier, since it may become null via a hidl callback
		std::mutex mLock;
		std::unique_ptr<MotionClassifierInterface> mMotionClassifier GUARDED_BY(mLock);
		// The next stage to pass input events to
		sp<InputListenerInterface> mListener;

		std::unique_ptr<MotionClassifierInterface> mMotionClassifier GUARDED_BY(mLock);
		std::thread mInitializeMotionClassifierThread;
		/**
		* Set the value of mMotionClassifier.
		* This is called from 2 different threads:
		* 1) mInitializeMotionClassifierThread, when we have constructed a MotionClassifier
		* 2) A binder thread of the HalDeathRecipient, which is created when HAL dies. This would cause
		* mMotionClassifier to become nullptr.
		*/
		void setMotionClassifier(std::unique_ptr<MotionClassifierInterface> motionClassifier);

		/**
		* The deathRecipient will call setMotionClassifier(null) when the HAL dies.
		*/
		class HalDeathRecipient : public android::hardware::hidl_death_recipient {
		public:
		explicit HalDeathRecipient(InputClassifier& parent);
		virtual void serviceDied(uint64_t cookie,
		const wp<android::hidl::base::V1_0::IBase>& who) override;

		private:
		InputClassifier& mParent;
		};
		// We retain a reference to death recipient, because the death recipient will be calling
		// ~MotionClassifier if the HAL dies.
		// If we don't retain a reference, and MotionClassifier is the only owner of the death
		// recipient, the serviceDied call will cause death recipient to call its own destructor.
		sp<HalDeathRecipient> mHalDeathRecipient;
		};

		} // namespace android

services/inputflinger/tests/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@ cc_test {
		"libutils",
		"libhardware",
		"libhardware_legacy",
		"libhidlbase",
		"libui",
		"libinput",
		"libinputflinger",

services/inputflinger/tests/InputClassifier_test.cpp

+32 −1

Original line number	Diff line number	Diff line
		@@ -22,6 +22,9 @@
		#include <android/hardware/input/classifier/1.0/IInputClassifier.h>

		using namespace android::hardware::input;
		using android::hardware::Return;
		using android::hardware::Void;
		using android::hardware::input::common::V1_0::Classification;

		namespace android {

		@@ -129,6 +132,27 @@ TEST_F(InputClassifierTest, SendToNextStage_NotifyDeviceResetArgs) {
		ASSERT_EQ(args, outArgs);
		}

		/**
		* A minimal implementation of IInputClassifier.
		*/
		struct TestHal : public android::hardware::input::classifier::V1_0::IInputClassifier {
		Return<Classification> classify(
		const android::hardware::input::common::V1_0::MotionEvent& event) override {
		return Classification::NONE;
		};
		Return<void> reset() override { return Void(); };
		Return<void> resetDevice(int32_t deviceId) override { return Void(); };
		};

		/**
		* An entity that will be subscribed to the HAL death.
		*/
		class TestDeathRecipient : public android::hardware::hidl_death_recipient {
		public:
		virtual void serviceDied(uint64_t cookie,
		const wp<android::hidl::base::V1_0::IBase>& who) override{};
		};

		// --- MotionClassifierTest ---

		class MotionClassifierTest : public testing::Test {
		@@ -136,7 +160,14 @@ protected:
		std::unique_ptr<MotionClassifierInterface> mMotionClassifier;

		virtual void SetUp() override {
		mMotionClassifier = std::make_unique<MotionClassifier>();
		mMotionClassifier = MotionClassifier::create(new TestDeathRecipient());
		if (mMotionClassifier == nullptr) {
		// If the device running this test does not have IInputClassifier service,
		// use the test HAL instead.
		// Using 'new' to access non-public constructor
		mMotionClassifier =
		std::unique_ptr<MotionClassifier>(new MotionClassifier(new TestHal()));
		}
		}
		};