genode/repos/os/include/regulator/component.h
Norman Feske 4d442bca30 Streamline exception types
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.

Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.

This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
2017-05-31 13:16:07 +02:00

105 lines
2.6 KiB
C++

/*
* \brief Regulator-session component
* \author Stefan Kalkowski
* \date 2013-06-13
*/
/*
* Copyright (C) 2013-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _INCLUDE__REGULATOR__COMPONENT_H_
#define _INCLUDE__REGULATOR__COMPONENT_H_
#include <root/component.h>
#include <regulator_session/rpc_object.h>
#include <regulator/driver.h>
namespace Regulator {
class Session_component;
class Root;
}
class Regulator::Session_component : public Regulator::Session_rpc_object
{
private:
Driver_factory & _driver_factory;
Driver & _driver;
public:
Session_component(Regulator_id regulator_id,
Driver_factory & driver_factory)
: Session_rpc_object(regulator_id),
_driver_factory(driver_factory),
_driver(_driver_factory.create(regulator_id)) { }
~Session_component()
{
_driver.state(_id, false);
_driver_factory.destroy(_driver);
}
/***********************************
** Regulator session interface **
***********************************/
void level(unsigned long level) { _driver.level(_id, level); }
unsigned long level() { return _driver.level(_id); }
void state(bool enable) { _driver.state(_id, enable); }
bool state() { return _driver.state(_id); }
};
class Regulator::Root :
public Genode::Root_component<Regulator::Session_component>
{
private:
Regulator::Driver_factory & _driver_factory;
protected:
Session_component *_create_session(const char *args)
{
using namespace Genode;
char reg_name[64];
Arg_string::find_arg(args, "regulator").string(reg_name,
sizeof(reg_name), 0);
size_t ram_quota =
Arg_string::find_arg(args, "ram_quota").ulong_value(0);
/* delete ram quota by the memory needed for the session */
size_t session_size = max((size_t)4096,
sizeof(Session_component));
if (ram_quota < session_size)
throw Insufficient_ram_quota();
if (!strlen(reg_name))
throw Service_denied();
return new (md_alloc())
Session_component(regulator_id_by_name(reg_name),
_driver_factory);
}
public:
Root(Genode::Env & env,
Genode::Allocator & md_alloc,
Regulator::Driver_factory & driver_factory)
: Genode::Root_component<Regulator::Session_component>(env.ep(),
md_alloc),
_driver_factory(driver_factory) { }
};
#endif /* _INCLUDE__REGULATOR__COMPONENT_H_ */