Merge "libbinder: s/mClients|mServers/\0Connections/g" am: ca4019be73 am:... (86d092cb) · Commits · e / os / android_frameworks_native

libs/binder/RpcSession.cpp

+17 −14

Original line number	Diff line number	Diff line
		@@ -49,7 +49,7 @@ RpcSession::~RpcSession() {
		LOG_RPC_DETAIL("RpcSession destroyed %p", this);

		std::lock_guard<std::mutex> _l(mMutex);
		LOG_ALWAYS_FATAL_IF(mServers.size() != 0,
		LOG_ALWAYS_FATAL_IF(mServerConnections.size() != 0,
		"Should not be able to destroy a session with servers in use.");
		}

		@@ -194,9 +194,9 @@ wp<RpcServer> RpcSession::server() {
		bool RpcSession::setupSocketClient(const RpcSocketAddress& addr) {
		{
		std::lock_guard<std::mutex> _l(mMutex);
		LOG_ALWAYS_FATAL_IF(mClients.size() != 0,
		LOG_ALWAYS_FATAL_IF(mClientConnections.size() != 0,
		"Must only setup session once, but already has %zu clients",
		mClients.size());
		mClientConnections.size());
		}

		if (!setupOneSocketClient(addr, RPC_SESSION_ID_NEW)) return false;
		@@ -261,7 +261,7 @@ void RpcSession::addClient(unique_fd fd) {
		std::lock_guard<std::mutex> _l(mMutex);
		sp<RpcConnection> session = sp<RpcConnection>::make();
		session->fd = std::move(fd);
		mClients.push_back(session);
		mClientConnections.push_back(session);
		}

		void RpcSession::setForServer(const wp<RpcServer>& server, int32_t sessionId) {
		@@ -274,16 +274,17 @@ sp<RpcSession::RpcConnection> RpcSession::assignServerToThisThread(unique_fd fd)
		sp<RpcConnection> session = sp<RpcConnection>::make();
		session->fd = std::move(fd);
		session->exclusiveTid = gettid();
		mServers.push_back(session);
		mServerConnections.push_back(session);

		return session;
		}

		bool RpcSession::removeServerConnection(const sp<RpcConnection>& connection) {
		std::lock_guard<std::mutex> _l(mMutex);
		if (auto it = std::find(mServers.begin(), mServers.end(), connection); it != mServers.end()) {
		mServers.erase(it);
		if (mServers.size() == 0) {
		if (auto it = std::find(mServerConnections.begin(), mServerConnections.end(), connection);
		it != mServerConnections.end()) {
		mServerConnections.erase(it);
		if (mServerConnections.size() == 0) {
		terminateLocked();
		}
		return true;
		@@ -305,10 +306,11 @@ RpcSession::ExclusiveConnection::ExclusiveConnection(const sp<RpcSession>& sessi
		// CHECK FOR DEDICATED CLIENT SOCKET
		//
		// A server/looper should always use a dedicated session if available
		findConnection(tid, &exclusive, &available, mSession->mClients, mSession->mClientsOffset);
		findConnection(tid, &exclusive, &available, mSession->mClientConnections,
		mSession->mClientConnectionsOffset);

		// WARNING: this assumes a server cannot request its client to send
		// a transaction, as mServers is excluded below.
		// a transaction, as mServerConnections is excluded below.
		//
		// Imagine we have more than one thread in play, and a single thread
		// sends a synchronous, then an asynchronous command. Imagine the
		@@ -318,7 +320,8 @@ RpcSession::ExclusiveConnection::ExclusiveConnection(const sp<RpcSession>& sessi
		// command. So, we move to considering the second available thread
		// for subsequent calls.
		if (use == ConnectionUse::CLIENT_ASYNC && (exclusive != nullptr \|\| available != nullptr)) {
		mSession->mClientsOffset = (mSession->mClientsOffset + 1) % mSession->mClients.size();
		mSession->mClientConnectionsOffset =
		(mSession->mClientConnectionsOffset + 1) % mSession->mClientConnections.size();
		}

		// USE SERVING SOCKET (for nested transaction)
		@@ -326,7 +329,7 @@ RpcSession::ExclusiveConnection::ExclusiveConnection(const sp<RpcSession>& sessi
		// asynchronous calls cannot be nested
		if (use != ConnectionUse::CLIENT_ASYNC) {
		// server connections are always assigned to a thread
		findConnection(tid, &exclusive, nullptr /available/, mSession->mServers,
		findConnection(tid, &exclusive, nullptr /available/, mSession->mServerConnections,
		0 /* index hint */);
		}

		@@ -342,13 +345,13 @@ RpcSession::ExclusiveConnection::ExclusiveConnection(const sp<RpcSession>& sessi
		}

		// in regular binder, this would usually be a deadlock :)
		LOG_ALWAYS_FATAL_IF(mSession->mClients.size() == 0,
		LOG_ALWAYS_FATAL_IF(mSession->mClientConnections.size() == 0,
		"Not a client of any session. You must create a session to an "
		"RPC server to make any non-nested (e.g. oneway or on another thread) "
		"calls.");

		LOG_RPC_DETAIL("No available session (have %zu clients and %zu servers). Waiting...",
		mSession->mClients.size(), mSession->mServers.size());
		mSession->mClientConnections.size(), mSession->mServerConnections.size());
		mSession->mAvailableConnectionCv.wait(_l);
		}
		mSession->mWaitingThreads--;

libs/binder/include/binder/RpcSession.h

+9 −8

Original line number	Diff line number	Diff line
		@@ -163,13 +163,13 @@ private:
		bool mReentrant = false;
		};

		// On the other side of a session, for each of mClients here, there should
		// be one of mServers on the other side (and vice versa).
		// On the other side of a session, for each of mClientConnections here, there should
		// be one of mServerConnections on the other side (and vice versa).
		//
		// For the simplest session, a single server with one client, you would
		// have:
		// - the server has a single 'mServers' and a thread listening on this
		// - the client has a single 'mClients' and makes calls to this
		// - the server has a single 'mServerConnections' and a thread listening on this
		// - the client has a single 'mClientConnections' and makes calls to this
		// - here, when the client makes a call, the server can call back into it
		// (nested calls), but outside of this, the client will only ever read
		// calls from the server when it makes a call itself.
		@@ -188,14 +188,15 @@ private:

		std::condition_variable mAvailableConnectionCv; // for mWaitingThreads
		size_t mWaitingThreads = 0;
		size_t mClientsOffset = 0; // hint index into clients, ++ when sending an async transaction
		std::vector<sp<RpcConnection>> mClients;
		std::vector<sp<RpcConnection>> mServers;
		// hint index into clients, ++ when sending an async transaction
		size_t mClientConnectionsOffset = 0;
		std::vector<sp<RpcConnection>> mClientConnections;
		std::vector<sp<RpcConnection>> mServerConnections;

		// TODO(b/185167543): use for reverse sessions (allow client to also
		// serve calls on a session).
		// TODO(b/185167543): allow sharing between different sessions in a
		// process? (or combine with mServers)
		// process? (or combine with mServerConnections)
		std::map<std::thread::id, std::thread> mThreads;
		bool mTerminated = false;
		};