genode/repos/os/include/report_rom/rom_service.h

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/*
* \brief ROM service
* \author Norman Feske
* \date 2014-01-11
*/
/*
* Copyright (C) 2014 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__REPORT_ROM__ROM_SERVICE_H_
#define _INCLUDE__REPORT_ROM__ROM_SERVICE_H_
/* Genode includes */
#include <util/arg_string.h>
#include <util/xml_node.h>
#include <rom_session/rom_session.h>
#include <root/component.h>
#include <report_rom/rom_registry.h>
#include <os/session_policy.h>
namespace Rom {
class Session_component;
class Module_name_fn;
class Root;
using Genode::Xml_node;
}
class Rom::Session_component : public Genode::Rpc_object<Genode::Rom_session>,
public Reader
{
private:
Registry_for_reader &_registry;
Genode::Session_label const _label;
Readable_module &_module;
Readable_module &_init_module(Genode::Session_label const &label)
{
try {
return _registry.lookup(*this, label.string()); }
catch (Registry_for_reader::Lookup_failed) {
throw Genode::Root::Invalid_args(); }
}
Lazy_volatile_object<Genode::Attached_ram_dataspace> _ds;
size_t _content_size = 0;
/**
* Keep state of valid content to notify the client only once when
* the ROM module becomes invalid.
*/
bool _valid = false;
Genode::Signal_context_capability _sigh;
void _notify_client()
{
if (_sigh.valid())
Genode::Signal_transmitter(_sigh).submit();
}
public:
Session_component(Registry_for_reader &registry,
Genode::Session_label const &label)
:
_registry(registry), _label(label), _module(_init_module(label))
{ }
~Session_component()
{
_registry.release(*this, _module);
}
Genode::Session_label label() const { return _label; }
Genode::Rom_dataspace_capability dataspace() override
{
using namespace Genode;
/* replace dataspace by new one */
/* XXX we could keep the old dataspace if the size fits */
_ds.construct(env()->ram_session(), _module.size());
/* fill dataspace content with report contained in module */
_content_size =
_module.read_content(*this, _ds->local_addr<char>(), _ds->size());
_valid = _content_size > 0;
/* cast RAM into ROM dataspace capability */
Dataspace_capability ds_cap = static_cap_cast<Dataspace>(_ds->cap());
return static_cap_cast<Rom_dataspace>(ds_cap);
}
bool update() override
{
if (!_ds.constructed() || _module.size() > _ds->size())
return false;
size_t const new_content_size =
_module.read_content(*this, _ds->local_addr<char>(), _ds->size());
/* clear difference between old and new content */
if (new_content_size < _content_size)
Genode::memset(_ds->local_addr<char>() + new_content_size, 0,
_content_size - new_content_size);
_content_size = new_content_size;
_valid = _content_size > 0;
return true;
}
void sigh(Genode::Signal_context_capability sigh) override
{
_sigh = sigh;
/*
* Notify client initially to enforce a client-side ROM update.
* Otherwise, a server-side ROM update between session creation and
* signal-handler registration would go unnoticed.
*/
_notify_client();
}
/**
* Reader interface
*/
void notify_module_changed() override
{
_notify_client();
}
/**
* Reader interface
*/
void notify_module_invalidated() override
{
/* deliver a signal for an invalidated module only once */
if (!_valid)
return;
_valid = false;
_notify_client();
}
};
class Rom::Root : public Genode::Root_component<Session_component>
{
private:
Registry_for_reader &_registry;
protected:
Session_component *_create_session(const char *args) override
{
using namespace Genode;
return new (md_alloc())
Session_component(_registry, Session_label(args));
}
public:
Root(Server::Entrypoint &ep,
Genode::Allocator &md_alloc,
Registry_for_reader &registry)
:
Genode::Root_component<Session_component>(&ep.rpc_ep(), &md_alloc),
_registry(registry)
{ }
};
#endif /* _INCLUDE__REPORT_ROM__ROM_SERVICE_H_ */