Introduce CaptureStateNotifier (987d12c4) · Commits · e / os / android_frameworks_av

media/libaudioclient/Android.bp

+12 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@ cc_library_shared {
		"AudioVolumeGroup.cpp",
		],
		shared_libs: [
		"capture_state_listener-aidl-cpp",
		"libaudiofoundation",
		"libaudioutils",
		"libbinder",
		@@ -34,6 +35,9 @@ cc_library_shared {
		],
		include_dirs: ["system/media/audio_utils/include"],
		export_include_dirs: ["include"],
		export_shared_lib_headers: [
		"capture_state_listener-aidl-cpp",
		],
		}

		cc_library_shared {
		@@ -148,3 +152,11 @@ filegroup {
		],
		path: "aidl",
		}

		aidl_interface {
		name: "capture_state_listener-aidl",
		local_include_dir: "aidl",
		srcs: [
		"aidl/android/media/ICaptureStateListener.aidl",
		],
		}

media/libaudioclient/aidl/android/media/ICaptureStateListener.aidl

0 → 100644

+21 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package android.media;

		interface ICaptureStateListener {
		void setCaptureState(boolean active);
		}

services/audiopolicy/service/Android.mk

+2 −1

Original line number	Diff line number	Diff line
		@@ -6,7 +6,8 @@ LOCAL_SRC_FILES:= \
		AudioPolicyService.cpp \
		AudioPolicyEffects.cpp \
		AudioPolicyInterfaceImpl.cpp \
		AudioPolicyClientImpl.cpp
		AudioPolicyClientImpl.cpp \
		CaptureStateNotifier.cpp

		LOCAL_C_INCLUDES := \
		frameworks/av/services/audioflinger \

services/audiopolicy/service/CaptureStateNotifier.cpp

0 → 100644

+58 −0

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		#include "CaptureStateNotifier.h"

		#define LOG_TAG "CaptureStateNotifier"

		#include <android/media/ICaptureStateListener.h>
		#include <binder/IBinder.h>
		#include <utils/Log.h>

		namespace android {

		using media::ICaptureStateListener;

		class CaptureStateNotifier::DeathRecipient : public IBinder::DeathRecipient {
		public:
		DeathRecipient(CaptureStateNotifier* notifier) : mNotifier(notifier) {}

		void binderDied(const wp<IBinder>&) override {
		mNotifier->binderDied();
		}

		private:
		CaptureStateNotifier* const mNotifier;
		};

		CaptureStateNotifier::CaptureStateNotifier(bool initialActive) {
		mActive = initialActive;
		}

		CaptureStateNotifier::~CaptureStateNotifier() {
		LOG_ALWAYS_FATAL_IF(mListener != nullptr);
		}

		bool CaptureStateNotifier::RegisterListener(const sp<ICaptureStateListener>& listener) {
		std::lock_guard<std::mutex> _l(mMutex);
		LOG_ALWAYS_FATAL_IF(mListener != nullptr);

		ALOGI("Registering a listener");
		mListener = listener;
		sp<IBinder> binder = IInterface::asBinder(mListener);
		binder->linkToDeath(new DeathRecipient(this));
		return mActive;
		}

		void CaptureStateNotifier::setCaptureState(bool active) {
		std::lock_guard<std::mutex> _l(mMutex);
		mActive = active;
		if (mListener) {
		mListener->setCaptureState(active);
		}
		}

		void CaptureStateNotifier::binderDied() {
		std::lock_guard<std::mutex> _l(mMutex);
		mListener.clear();
		ALOGI("Listener binder died");
		}

		} // namespace android
		No newline at end of file

services/audiopolicy/service/CaptureStateNotifier.h

0 → 100644

+73 −0

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		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#pragma once

		#include <mutex>
		#include <utils/StrongPointer.h>

		namespace android {
		namespace media {
		// Must be pre-declared, or else there isn't a good way to generate a header
		// library.
		class ICaptureStateListener;
		}

		// A utility for managing capture state change notifications.
		//
		// We are making some strong assumptions, for the sake of simplicity:
		// - There is no way to explicitly unregister listeners. The only way for a
		// listener to unregister is by dying.
		// - There's only at most one listener at a given time. Attempting to register
		// a second listener will cause a crash.
		// - This class isn't really meant to ever be destroyed. We expose a destructor
		// because it is convenient to use this class as a global instance or a member
		// of another class, but it will crash if destroyed while a listener is
		// registered.
		//
		// All of these assumptions can be lifted if there is ever a need.
		//
		// This class is thread-safe.
		class CaptureStateNotifier {
		public:
		// Ctor.
		// Accepts the initial active state.
		explicit CaptureStateNotifier(bool initialActive);

		// Register a listener to be notified of state changes.
		// The current state is returned and from that point on any change will be
		// notified of.
		bool RegisterListener(const sp<media::ICaptureStateListener>& listener);

		// Change the current capture state.
		// Active means "actively capturing".
		void setCaptureState(bool active);

		// Dtor. Do not actually call at runtime. Will cause a crash if a listener
		// is registered.
		~CaptureStateNotifier();

		private:
		std::mutex mMutex;
		sp<media::ICaptureStateListener> mListener;
		bool mActive;

		class DeathRecipient;

		void binderDied();
		};

		} // namespace android