genode/repos/os/include/usb_session/connection.h
2024-05-29 09:18:12 +02:00

116 lines
2.9 KiB
C++

/*
* \brief Client connection to USB server
* \author Stefan Kalkowski
* \author Sebastian Sumpf
* \date 2014-12-08
*/
/*
* Copyright (C) 2014-2024 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__USB_SESSION__CONNECTION_H_
#define _INCLUDE__USB_SESSION__CONNECTION_H_
#include <base/attached_dataspace.h>
#include <base/connection.h>
#include <rom_session/client.h>
#include <usb_session/client.h>
namespace Usb { struct Connection; }
class Usb::Connection : public Genode::Connection<Session>, public Usb::Client
{
private:
Env & _env;
Rom_session_client _rom { devices_rom() };
Constructible<Attached_dataspace> _ds {};
Io_signal_handler<Connection> _handler { _env.ep(), *this,
&Connection::_handle_io };
void _try_attach()
{
_ds.destruct();
try { _ds.construct(_env.rm(), _rom.dataspace()); }
catch (Attached_dataspace::Invalid_dataspace) {
warning("Invalid devices rom dataspace returned!");}
}
void _handle_io() { }
Device_capability _wait_for_device(auto const & fn)
{
for (;;) {
/* repeatedly check for availability of device */
Device_capability cap = fn();
if (cap.valid())
return cap;
_env.ep().wait_and_dispatch_one_io_signal();
}
}
public:
Connection(Genode::Env &env,
Genode::size_t ram_quota = RAM_QUOTA)
:
Genode::Connection<Session>(env, Label(),
Ram_quota { ram_quota }, Args()),
Client(cap()),
_env(env)
{
_try_attach();
/*
* Initially register dummy handler, to be able to receive signals
* if _wait_for_device probes for a valid devices rom
*/
sigh(_handler);
}
void update()
{
if (_ds.constructed() && _rom.update() == true)
return;
_try_attach();
}
void sigh(Signal_context_capability sigh) { _rom.sigh(sigh); }
void with_xml(auto const & fn)
{
update();
try {
if (_ds.constructed() && _ds->local_addr<void const>()) {
Xml_node xml(_ds->local_addr<char>(), _ds->size());
fn(xml);
}
} catch (Xml_node::Invalid_syntax) {
warning("Devices rom has invalid XML syntax"); }
}
Device_capability acquire_device(Device_name const &name) override
{
Ram_quota ram_quota(Device_session::TX_BUFFER_SIZE + 4096);
return retry_with_upgrade(ram_quota, Cap_quota{6}, [&] () {
return Client::acquire_device(name); });
}
Device_capability acquire_device()
{
return _wait_for_device([&] () {
Ram_quota ram_quota(Device_session::TX_BUFFER_SIZE + 4096);
return retry_with_upgrade(ram_quota, Cap_quota{6}, [&] () {
return Client::acquire_single_device(); });
});
}
};
#endif /* _INCLUDE__USB_SESSION__CONNECTION_H_ */