Merge "libbinder: fix RPC setup races" (4b02e9cf) · Commits · e / devices / smdk4412 / android_frameworks_native

libs/binder/RpcServer.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -369,7 +369,7 @@ bool RpcServer::setupSocketServer(const RpcSocketAddress& addr) {
		return true;
		}

		void RpcServer::onSessionLockedAllIncomingThreadsEnded(const sp<RpcSession>& session) {
		void RpcServer::onSessionAllIncomingThreadsEnded(const sp<RpcSession>& session) {
		auto id = session->mId;
		LOG_ALWAYS_FATAL_IF(id == std::nullopt, "Server sessions must be initialized with ID");
		LOG_RPC_DETAIL("Dropping session with address %s", id->toString().c_str());

libs/binder/RpcSession.cpp

+30 −8

Original line number	Diff line number	Diff line
		@@ -132,6 +132,7 @@ bool RpcSession::shutdownAndWait(bool wait) {
		if (wait) {
		LOG_ALWAYS_FATAL_IF(mShutdownListener == nullptr, "Shutdown listener not installed");
		mShutdownListener->waitForShutdown(_l);

		LOG_ALWAYS_FATAL_IF(!mThreads.empty(), "Shutdown failed");
		}

		@@ -259,7 +260,7 @@ status_t RpcSession::readId() {
		return OK;
		}

		void RpcSession::WaitForShutdownListener::onSessionLockedAllIncomingThreadsEnded(
		void RpcSession::WaitForShutdownListener::onSessionAllIncomingThreadsEnded(
		const sp<RpcSession>& session) {
		(void)session;
		mShutdown = true;
		@@ -291,7 +292,13 @@ RpcSession::PreJoinSetupResult RpcSession::preJoinSetup(base::unique_fd fd) {
		// be able to do nested calls (we can't only read from it)
		sp<RpcConnection> connection = assignIncomingConnectionToThisThread(std::move(fd));

		status_t status = mState->readConnectionInit(connection, sp<RpcSession>::fromExisting(this));
		status_t status;

		if (connection == nullptr) {
		status = DEAD_OBJECT;
		} else {
		status = mState->readConnectionInit(connection, sp<RpcSession>::fromExisting(this));
		}

		return PreJoinSetupResult{
		.connection = std::move(connection),
		@@ -358,6 +365,7 @@ void RpcSession::join(sp<RpcSession>&& session, PreJoinSetupResult&& setupResult
		sp<RpcConnection>& connection = setupResult.connection;

		if (setupResult.status == OK) {
		LOG_ALWAYS_FATAL_IF(!connection, "must have connection if setup succeeded");
		JavaThreadAttacher javaThreadAttacher;
		while (true) {
		status_t status = session->state()->getAndExecuteCommand(connection, session,
		@@ -373,9 +381,6 @@ void RpcSession::join(sp<RpcSession>&& session, PreJoinSetupResult&& setupResult
		statusToString(setupResult.status).c_str());
		}

		LOG_ALWAYS_FATAL_IF(!session->removeIncomingConnection(connection),
		"bad state: connection object guaranteed to be in list");

		sp<RpcSession::EventListener> listener;
		{
		std::lock_guard<std::mutex> _l(session->mMutex);
		@@ -387,6 +392,12 @@ void RpcSession::join(sp<RpcSession>&& session, PreJoinSetupResult&& setupResult
		listener = session->mEventListener.promote();
		}

		// done after all cleanup, since session shutdown progresses via callbacks here
		if (connection != nullptr) {
		LOG_ALWAYS_FATAL_IF(!session->removeIncomingConnection(connection),
		"bad state: connection object guaranteed to be in list");
		}

		session = nullptr;

		if (listener != nullptr) {
		@@ -577,24 +588,35 @@ bool RpcSession::setForServer(const wp<RpcServer>& server, const wp<EventListene

		sp<RpcSession::RpcConnection> RpcSession::assignIncomingConnectionToThisThread(unique_fd fd) {
		std::lock_guard<std::mutex> _l(mMutex);

		// Don't accept any more connections, some have shutdown. Usually this
		// happens when new connections are still being established as part of a
		// very short-lived session which shuts down after it already started
		// accepting new connections.
		if (mIncomingConnections.size() < mMaxIncomingConnections) {
		return nullptr;
		}

		sp<RpcConnection> session = sp<RpcConnection>::make();
		session->fd = std::move(fd);
		session->exclusiveTid = gettid();

		mIncomingConnections.push_back(session);
		mMaxIncomingConnections = mIncomingConnections.size();

		return session;
		}

		bool RpcSession::removeIncomingConnection(const sp<RpcConnection>& connection) {
		std::lock_guard<std::mutex> _l(mMutex);
		std::unique_lock<std::mutex> _l(mMutex);
		if (auto it = std::find(mIncomingConnections.begin(), mIncomingConnections.end(), connection);
		it != mIncomingConnections.end()) {
		mIncomingConnections.erase(it);
		if (mIncomingConnections.size() == 0) {
		sp<EventListener> listener = mEventListener.promote();
		if (listener) {
		listener->onSessionLockedAllIncomingThreadsEnded(
		sp<RpcSession>::fromExisting(this));
		_l.unlock();
		listener->onSessionAllIncomingThreadsEnded(sp<RpcSession>::fromExisting(this));
		}
		}
		return true;

libs/binder/include/binder/RpcServer.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -156,7 +156,7 @@ private:
		friend sp<RpcServer>;
		RpcServer();

		void onSessionLockedAllIncomingThreadsEnded(const sp<RpcSession>& session) override;
		void onSessionAllIncomingThreadsEnded(const sp<RpcSession>& session) override;
		void onSessionIncomingThreadEnded() override;

		static void establishConnection(sp<RpcServer>&& server, base::unique_fd clientFd);

libs/binder/include/binder/RpcSession.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -177,19 +177,19 @@ private:

		class EventListener : public virtual RefBase {
		public:
		virtual void onSessionLockedAllIncomingThreadsEnded(const sp<RpcSession>& session) = 0;
		virtual void onSessionAllIncomingThreadsEnded(const sp<RpcSession>& session) = 0;
		virtual void onSessionIncomingThreadEnded() = 0;
		};

		class WaitForShutdownListener : public EventListener {
		public:
		void onSessionLockedAllIncomingThreadsEnded(const sp<RpcSession>& session) override;
		void onSessionAllIncomingThreadsEnded(const sp<RpcSession>& session) override;
		void onSessionIncomingThreadEnded() override;
		void waitForShutdown(std::unique_lock<std::mutex>& lock);

		private:
		std::condition_variable mCv;
		bool mShutdown = false;
		volatile bool mShutdown = false;
		};

		struct RpcConnection : public RefBase {
		@@ -297,6 +297,7 @@ private:
		// hint index into clients, ++ when sending an async transaction
		size_t mOutgoingConnectionsOffset = 0;
		std::vector<sp<RpcConnection>> mOutgoingConnections;
		size_t mMaxIncomingConnections = 0;
		std::vector<sp<RpcConnection>> mIncomingConnections;
		std::map<std::thread::id, std::thread> mThreads;
		};