genode/base/include/parent/parent.h

223 lines
7.2 KiB
C++

/*
* \brief Parent interface
* \author Norman Feske
* \date 2006-05-10
*/
/*
* 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__PARENT__PARENT_H_
#define _INCLUDE__PARENT__PARENT_H_
#include <base/exception.h>
#include <base/rpc.h>
#include <base/rpc_args.h>
#include <base/thread.h>
#include <session/capability.h>
#include <root/capability.h>
namespace Genode {
class Parent
{
private:
/**
* Recursively announce inherited service interfaces
*
* At compile time, the 'ROOT' type is inspected for the presence
* of the 'Rpc_inherited_interface' type in the corresponding
* session interface. If present, the session type gets announced.
* This works recursively.
*/
template <typename ROOT>
void _announce_base(Capability<ROOT> const &, Meta::Bool_to_type<false> *) { }
/*
* This overload gets selected if the ROOT interface corresponds to
* an inherited session type.
*/
template <typename ROOT>
inline void _announce_base(Capability<ROOT> const &, Meta::Bool_to_type<true> *);
public:
/*********************
** Exception types **
*********************/
class Exception : public ::Genode::Exception { };
class Service_denied : public Exception { };
class Quota_exceeded : public Exception { };
class Unavailable : public Exception { };
typedef Rpc_in_buffer<64> Service_name;
typedef Rpc_in_buffer<160> Session_args;
typedef Rpc_in_buffer<160> Upgrade_args;
virtual ~Parent() { }
/**
* Tell parent to exit the program
*/
virtual void exit(int exit_value) = 0;
/**
* Announce service to the parent
*/
virtual void announce(Service_name const &service_name,
Root_capability service_root) = 0;
/**
* Announce service to the parent
*
* \param service_root root capability
*
* The type of the specified 'service_root' capability match with
* an interface that provides a 'Session_type' type (i.e., a
* 'Typed_root' interface). This 'Session_type' is expected to
* host a static function called 'service_name' returning the
* name of the provided interface as null-terminated string.
*/
template <typename ROOT_INTERFACE>
void announce(Capability<ROOT_INTERFACE> const &service_root)
{
typedef typename ROOT_INTERFACE::Session_type Session;
announce(Session::service_name(), service_root);
/*
* Announce inherited session types
*
* Select the overload based on the presence of the type
* 'Rpc_inherited_interface' within the session type.
*/
_announce_base(service_root,
(Meta::Bool_to_type<Rpc_interface_is_inherited<Session>::VALUE> *)0);
}
/**
* Create session to a service
*
* \param service_name name of the requested interface
* \param args session constructor arguments
* \param affinity preferred CPU affinity for the session
*
* \throw Service_denied parent denies session request
* \throw Quota_exceeded our own quota does not suffice for
* the creation of the new session
* \throw Unavailable
*
* \return untyped capability to new session
*
* The use of this function is discouraged. Please use the type safe
* 'session()' template instead.
*/
virtual Session_capability session(Service_name const &service_name,
Session_args const &args,
Affinity const &affinity = Affinity()) = 0;
/**
* Create session to a service
*
* \param SESSION_TYPE session interface type
* \param args session constructor arguments
* \param affinity preferred CPU affinity for the session
*
* \throw Service_denied parent denies session request
* \throw Quota_exceeded our own quota does not suffice for
* the creation of the new session
* \throw Unavailable
*
* \return capability to new session
*/
template <typename SESSION_TYPE>
Capability<SESSION_TYPE> session(Session_args const &args,
Affinity const &affinity = Affinity())
{
Session_capability cap = session(SESSION_TYPE::service_name(),
args, affinity);
return reinterpret_cap_cast<SESSION_TYPE>(cap);
}
/**
* Transfer our quota to the server that provides the specified session
*
* \param to_session recipient session
* \param args description of the amount of quota to transfer
*
* \throw Quota_exceeded quota could not be transferred
*
* The 'args' argument has the same principle format as the 'args'
* argument of the 'session' function.
* The error case indicates that there is not enough unused quota on
* the source side.
*/
virtual void upgrade(Session_capability to_session,
Upgrade_args const &args) = 0;
/**
* Close session
*/
virtual void close(Session_capability session) = 0;
/**
* Provide thread_cap of main thread
*/
virtual Thread_capability main_thread_cap() const = 0;
/*********************
** RPC declaration **
*********************/
GENODE_RPC(Rpc_exit, void, exit, int);
GENODE_RPC(Rpc_announce, void, announce,
Service_name const &, Root_capability);
GENODE_RPC_THROW(Rpc_session, Session_capability, session,
GENODE_TYPE_LIST(Service_denied, Quota_exceeded, Unavailable),
Service_name const &, Session_args const &, Affinity const &);
GENODE_RPC_THROW(Rpc_upgrade, void, upgrade,
GENODE_TYPE_LIST(Quota_exceeded),
Session_capability, Upgrade_args const &);
GENODE_RPC(Rpc_close, void, close, Session_capability);
GENODE_RPC(Rpc_main_thread, Thread_capability, main_thread_cap);
GENODE_RPC_INTERFACE(Rpc_exit, Rpc_announce, Rpc_session, Rpc_upgrade,
Rpc_close, Rpc_main_thread);
};
}
template <typename ROOT_INTERFACE>
void
Genode::Parent::_announce_base(Genode::Capability<ROOT_INTERFACE> const &service_root,
Genode::Meta::Bool_to_type<true> *)
{
/* shortcut for inherited session type */
typedef typename ROOT_INTERFACE::Session_type::Rpc_inherited_interface
Session_type_inherited;
/* shortcut for root interface type matching the inherited session type */
typedef Typed_root<Session_type_inherited> Root_inherited;
/* convert root capability to match the inherited session type */
Capability<Root> root = service_root;
Capability<Root_inherited> root_inherited = static_cap_cast<Root_inherited>(root);
/* announce inherited service type */
announce(Session_type_inherited::service_name(), root_inherited);
/* recursively announce further inherited session types */
_announce_base(root_inherited,
(Meta::Bool_to_type<Rpc_interface_is_inherited<Session_type_inherited>::VALUE> *)0);
}
#endif /* _INCLUDE__PARENT__PARENT_H_ */