genode/base/include/root/root.h

/*
 * \brief  Root interface
 * \author Norman Feske
 * \date   2006-05-11
 */

/*
 * Copyright (C) 2006-2013 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU General Public License version 2.
 */

#ifndef _INCLUDE__ROOT__ROOT_H_
#define _INCLUDE__ROOT__ROOT_H_

#include <base/exception.h>
#include <base/rpc.h>
#include <base/rpc_args.h>
#include <session/capability.h>

namespace Genode {

	struct Root
	{
		/*********************
		 ** Exception types **
		 *********************/

		class Exception      : public ::Genode::Exception { };
		class Unavailable    : public Exception { };
		class Quota_exceeded : public Exception { };
		class Invalid_args   : public Exception { };

		typedef Rpc_in_buffer<160> Session_args;
		typedef Rpc_in_buffer<160> Upgrade_args;

		virtual ~Root() { }

		/**
		 * Create session
		 *
		 * \throw Unavailable
		 * \throw Quota_exceeded
		 * \throw Invalid_args
		 *
		 * \return capability to new session
		 */
		virtual Session_capability session(Session_args const &args) = 0;

		/**
		 * Extend resource donation to an existing session
		 */
		virtual void upgrade(Session_capability session, Upgrade_args const &args) = 0;

		/**
		 * Close session
		 */
		virtual void close(Session_capability session) = 0;


		/*********************
		 ** RPC declaration **
		 *********************/

		GENODE_RPC_THROW(Rpc_session, Session_capability, session,
		                 GENODE_TYPE_LIST(Unavailable, Quota_exceeded, Invalid_args),
		                 Session_args const &);
		GENODE_RPC_THROW(Rpc_upgrade, void, upgrade,
		                 GENODE_TYPE_LIST(Invalid_args),
		                 Session_capability, Upgrade_args const &);
		GENODE_RPC(Rpc_close, void, close, Session_capability);

		GENODE_RPC_INTERFACE(Rpc_session, Rpc_upgrade, Rpc_close);
	};


	/**
	 * Root interface supplemented with information about the managed
	 * session type
	 *
	 * This class template is used to automatically propagate the
	 * correct session type to 'Parent::announce()' when announcing
	 * a service.
	 */
	template <typename SESSION_TYPE>
	struct Typed_root : Root
	{
		typedef SESSION_TYPE Session_type;
	};
}

#endif /* _INCLUDE__ROOT__ROOT_H_ */