/home/andref/projetos/epos--/include/alarm.h

// EPOS-- Alarm Abstraction Declarations

// This work is licensed under the Creative Commons
// Attribution-NonCommercial-NoDerivs License. To view a copy of this license,
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// Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.

#ifndef __alarm_h
#define __alarm_h

#include <system/config.h>
#include <utility/queue.h>
#include <tsc.h>
#include <rtc.h>
#include <timer.h>
#include <semaphore.h>

__BEGIN_SYS

class Alarm {
public:
    typedef void (*Handler)();
private:
    static const Type_Id TYPE = Type<Alarm>::TYPE;

    static const int FREQUENCY = __SYS(Traits)<Timer>::FREQUENCY;

    static const bool ATOMIC = true;

    typedef Relative_Queue<Alarm, List_Element_Rank, ATOMIC> AlarmQueue;

        typedef Queue<Handler, ATOMIC> HandlerQueue;

public:
    // Infinite times (for alarms)
    enum { INFINITE = 0 };

public:
        static const int SINGLE_TIME = 1;

        Alarm(const RTC::Microseconds & time, int times, Handler handler);

    Alarm(const RTC::Microseconds& time, int times);

    ~Alarm();

    void wait();

    static TSC::Hertz frequency() {     return _timer.frequency(); }

    static void delay(const RTC::Microseconds& time);

    static int init(System_Info* si);

        static int alarmLoop();

        static RTC::Microseconds period() { return 1000000 / frequency(); }

private:
        friend class Scheduler;

    static void master(const RTC::Microseconds& time, const Handler& handler);

    static void timerHandler(void);

private:
    Timer::Tick _ticks;
    int _times;
    AlarmQueue::Element _link;

    Semaphore _sem;

        Handler _handler;
        HandlerQueue::Element _handlerLink;

    static Timer _timer;

    static volatile Timer::Tick _elapsed;

    static Handler _master;

    static Timer::Tick _masterTicks;

    static AlarmQueue _requests;

        static HandlerQueue _handlerQueue;

        static Thread *_alarmThread;
};

__END_SYS

#endif

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