Merge "ServiceSingleton: prevent recaching an equivalent interface" into main (ce7e4aa4) · Commits · e / os / android_frameworks_av

media/utils/include/mediautils/BinderGenericUtils.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,24 @@ template<typename Interface>
		return interface->asBinder();
		}

		/**
		* Returns true if two interfaces pointer-match, or represent identical binder objects.
		*
		* C++ with C++ and NDK with NDK interfaces may be compared.
		*
		* It currently isn't possible through the NDK public interface to extract
		* the underlying C++ binder object, so we don't allow NDK and C++ interfaces to
		* be cross-checked even though they might be backed by the same binder object.
		*/
		static inline bool isSameInterface(const sp<IInterface>& a, const sp<IInterface>& b) {
		return a == b \|\| (a && b && IInterface::asBinder(a) == IInterface::asBinder(b));
		}

		static inline bool isSameInterface(const std::shared_ptr<::ndk::ICInterface>& a,
		const std::shared_ptr<::ndk::ICInterface>& b) {
		return a == b \|\| (a && b && a->asBinder() == b->asBinder());
		}

		/**
		* Returns either a sp<Interface> or a std::shared_ptr<Interface> from a Binder object.
		*

media/utils/include/mediautils/ServiceSingleton.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -318,7 +318,9 @@ private:
		[traits, this](const InterfaceType<Service>& service) {
		audio_utils::unique_lock ul(mMutex);
		auto originalService = std::get<BaseInterfaceType<Service>>(mService);
		if (originalService != service) {
		// we suppress equivalent services from being set
		// where either the pointers match or the binder objects match.
		if (!mediautils::isSameInterface(originalService, service)) {
		if (originalService != nullptr) {
		invalidateService_l<Service>();
		}
		@@ -346,6 +348,8 @@ private:
		// sets the death notifier for mService (mService must be non-null).
		template <typename Service>
		void setDeathNotifier_l(const BaseInterfaceType<Service>& base) REQUIRES(mMutex) {
		// here the pointer match should be identical to binder object match
		// since we use a cached service.
		if (base != std::get<BaseInterfaceType<Service>>(mService)) {
		ALOGW("%s: service has changed for %s, skipping death notification registration",
		__func__, toString(Service::descriptor).c_str());

media/utils/tests/service_singleton_tests.cpp

+26 −0

Original line number	Diff line number	Diff line
		@@ -251,9 +251,35 @@ TEST(service_singleton_tests, one_and_only) {
		auto service = mediautils::getService<IServiceSingletonTest>();
		EXPECT_TRUE(service);

		// mediautils::getService<> is a cached service.
		// pointer equality is preserved for subsequent requests.
		auto service_equal = mediautils::getService<IServiceSingletonTest>();
		EXPECT_EQ(service, service_equal);
		EXPECT_TRUE(mediautils::isSameInterface(service, service_equal));

		// we can create an alias to the service by requesting it outside of the cache.
		// this is a different pointer, but same underlying binder object.
		auto service_equivalent =
		mediautils::checkServicePassThrough<IServiceSingletonTest>();
		EXPECT_NE(service, service_equivalent);
		EXPECT_TRUE(mediautils::isSameInterface(service, service_equivalent));

		auto service2 = mediautils::getService<aidl::IServiceSingletonTest>();
		EXPECT_TRUE(service2);

		// mediautils::getService<> is a cached service.
		// pointer equality is preserved for subsequent requests.
		auto service2_equal = mediautils::getService<aidl::IServiceSingletonTest>();
		EXPECT_EQ(service2, service2_equal);
		EXPECT_TRUE(mediautils::isSameInterface(service2, service2_equal));

		// we can create an alias to the service by requesting it outside of the cache.
		// this is a different pointer, but same underlying binder object.
		auto service2_equivalent =
		mediautils::checkServicePassThrough<aidl::IServiceSingletonTest>();
		EXPECT_NE(service2, service2_equivalent);
		EXPECT_TRUE(mediautils::isSameInterface(service2, service2_equivalent));

		keepAlive = service2;

		// we can also request our own death notifications (outside of the service traits).