genode/repos/demo/include/scout/tick.h
2017-02-28 12:59:29 +01:00

90 lines
1.5 KiB
C++

/*
* \brief Timed event scheduler interface
* \date 2005-10-24
* \author Norman Feske <norman.feske@genode-labs.com>
*/
/*
* Copyright (C) 2005-2017 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__SCOUT__TICK_H_
#define _INCLUDE__SCOUT__TICK_H_
namespace Scout { class Tick; }
class Scout::Tick
{
public:
typedef unsigned long time;
private:
/**
* Tick object attributes
*/
time _deadline; /* next deadline */
time _period; /* duration between ticks */
Tick *_next; /* next tick in tick list */
int _active; /* set to one when active */
/**
* Enqueue tick into tick queue
*/
void _enqueue();
/**
* Dequeue tick from tick queue (for destruction of Tick)
*/
void _dequeue();
protected:
/**
* Function to be called on when deadline is reached
*
* This function must be implemented by a derived class.
* If the return value is 1, the tick is scheduled again.
*/
virtual int on_tick() = 0;
public:
Tick()
{
_deadline = 0;
_period = 0;
_active = 0;
_next = 0;
}
virtual ~Tick() { _dequeue(); }
/**
* Schedule tick
*
* \param tick period
*/
void schedule(time period);
/**
* Return the number of scheduled ticks
*/
static int ticks_scheduled();
/**
* Handle ticks
*
* \param now current time
*/
static void handle(time now);
};
#endif /* _INCLUDE__SCOUT__TICK_H_ */