genode/repos/os/include/input/event_queue.h
Norman Feske b6f8bcca6a os: Add Input::Event_queue::reset function
Resetting the input-event queue is useful for error handling.

Issue #1185
2014-06-27 14:07:03 +02:00

86 lines
1.7 KiB
C++

/*
* \brief Input event queue
* \author Norman Feske
* \date 2007-10-08
*/
/*
* Copyright (C) 2007-2014 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 _EVENT_QUEUE_H_
#define _EVENT_QUEUE_H_
#include <base/signal.h>
#include <input/event.h>
#include <os/ring_buffer.h>
namespace Input { class Event_queue; };
class Input::Event_queue
{
public:
/**
* Input event queue
*
* We expect the client to fetch events circa each 10ms. The PS/2 driver
* queues up to 255 events, which should be enough. Normally, PS/2
* generates not more than 16Kbit/s, which would correspond to ca. 66 mouse
* events per 10ms.
*/
enum { QUEUE_SIZE = 512U };
private:
Ring_buffer<Input::Event, QUEUE_SIZE> _queue;
bool _enabled = false;
Genode::Signal_context_capability _sigh;
public:
typedef typename Ring_buffer<Input::Event, QUEUE_SIZE>::Overflow Overflow;
void enabled(bool enabled) { _enabled = enabled; }
bool enabled() const { return _enabled; }
void sigh(Genode::Signal_context_capability sigh) { _sigh = sigh; }
void submit_signal()
{
if (_sigh.valid())
Genode::Signal_transmitter(_sigh).submit();
}
/**
* \throw Overflow
*/
void add(Input::Event ev, bool submit_signal_immediately = true)
{
if (!_enabled)
return;
_queue.add(ev);
if (submit_signal_immediately)
submit_signal();
}
Input::Event get() { return _queue.get(); }
bool empty() const { return _queue.empty(); }
int avail_capacity() const { return _queue.avail_capacity(); }
void reset() { _queue.reset(); }
};
#endif /* _EVENT_QUEUE_H_ */