Merge "LazyServiceRegistrar: Add flag to prevent shutdown" am: 0d899f6c8a (74b017b2) · Commits · e / os / android_frameworks_native-old

cmds/servicemanager/ServiceManager.cpp

+2 −0

Original line number	Diff line number	Diff line
		@@ -532,6 +532,8 @@ Status ServiceManager::tryUnregisterService(const std::string& name, const sp<IB
		if (clients < 0 \|\| clients > 2) {
		// client callbacks are either disabled or there are other clients
		LOG(INFO) << "Tried to unregister " << name << ", but there are clients: " << clients;
		// Set this flag to ensure the clients are acknowledged in the next callback
		serviceIt->second.guaranteeClient = true;
		return Status::fromExceptionCode(Status::EX_ILLEGAL_STATE);
		}

libs/binder/LazyServiceRegistrar.cpp

+31 −5

Original line number	Diff line number	Diff line
		@@ -31,11 +31,16 @@ using AidlServiceManager = android::os::IServiceManager;

		class ClientCounterCallback : public ::android::os::BnClientCallback {
		public:
		ClientCounterCallback() : mNumConnectedServices(0) {}
		ClientCounterCallback() : mNumConnectedServices(0), mForcePersist(false) {}

		bool registerService(const sp<IBinder>& service, const std::string& name,
		bool allowIsolated, int dumpFlags);

		/**
		* Set a flag to prevent services from automatically shutting down
		*/
		void forcePersist(bool persist);

		protected:
		Status onClients(const sp<IBinder>& service, bool clients) override;

		@@ -60,6 +65,8 @@ private:
		* Map of registered names and services
		*/
		std::map<std::string, Service> mRegisteredServices;

		bool mForcePersist;
		};

		bool ClientCounterCallback::registerService(const sp<IBinder>& service, const std::string& name,
		@@ -88,6 +95,14 @@ bool ClientCounterCallback::registerService(const sp<IBinder>& service, const st
		return true;
		}

		void ClientCounterCallback::forcePersist(bool persist) {
		mForcePersist = persist;
		if(!mForcePersist) {
		// Attempt a shutdown in case the number of clients hit 0 while the flag was on
		tryShutdown();
		}
		}

		/**
		* onClients is oneway, so no need to worry about multi-threading. Note that this means multiple
		* invocations could occur on different threads however.
		@@ -103,14 +118,21 @@ Status ClientCounterCallback::onClients(const sp<IBinder>& service, bool clients
		mNumConnectedServices, mRegisteredServices.size(),
		String8(service->getInterfaceDescriptor()).string(), clients);

		if (mNumConnectedServices == 0) {
		tryShutdown();
		}

		return Status::ok();
		}

		void ClientCounterCallback::tryShutdown() {
		if(mNumConnectedServices > 0) {
		// Should only shut down if there are no clients
		return;
		}

		if(mForcePersist) {
		ALOGI("Shutdown prevented by forcePersist override flag.");
		return;
		}

		ALOGI("Trying to shut down the service. No clients in use for any service in process.");

		auto manager = interface_cast<AidlServiceManager>(asBinder(defaultServiceManager()));
		@@ -165,5 +187,9 @@ status_t LazyServiceRegistrar::registerService(const sp<IBinder>& service, const
		return OK;
		}

		void LazyServiceRegistrar::forcePersist(bool persist) {
		mClientCC->forcePersist(persist);
		}

		} // namespace hardware
		} // namespace android
		No newline at end of file

libs/binder/include/binder/LazyServiceRegistrar.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,12 @@ class LazyServiceRegistrar {
		const std::string& name = "default",
		bool allowIsolated = false,
		int dumpFlags = IServiceManager::DUMP_FLAG_PRIORITY_DEFAULT);
		/**
		* Force the service to persist, even when it has 0 clients.
		* If setting this flag from the server side, make sure to do so before calling registerService,
		* or there may be a race with the default dynamic shutdown.
		*/
		void forcePersist(bool persist);

		private:
		std::shared_ptr<internal::ClientCounterCallback> mClientCC;