Notifier.h

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008. All Rights Reserved.                                                         */
/* Open Source Software - may be modified and shared by FRC teams. The code   */
/* must be accompanied by the FIRST BSD license file in $(WIND_BASE)/WPILib.  */
/*----------------------------------------------------------------------------*/

#ifndef NOTIFIER_H
#define NOTIFIER_H

#include "ChipObject.h"
#include "ErrorBase.h"
#include "Synchronized.h"

typedef void (*TimerEventHandler)(void *param);

class Notifier : public ErrorBase
{
public:
        Notifier(TimerEventHandler handler, void *param = NULL);
        virtual ~Notifier();
        void StartSingle(double delay);
        void StartPeriodic(double period);
        void Stop();
private:
        static Notifier *timerQueueHead;
        static ReentrantSemaphore queueSemaphore;
        static tAlarm *talarm;
        static tInterruptManager *manager;
        static int refcount;

        static const uint32_t kTimerInterruptNumber = 28;
        static void ProcessQueue(uint32_t mask, void *params); // process the timer queue on a timer event
        static void UpdateAlarm();                      // update the FPGA alarm since the queue has changed
        void InsertInQueue(bool reschedule);    // insert this Notifier in the timer queue
        void DeleteFromQueue();                         // delete this Notifier from the timer queue
        TimerEventHandler m_handler;                    // address of the handler
        void *m_param;                                                  // a parameter to pass to the handler
        double m_period;                                                // the relative time (either periodic or single)
        double m_expirationTime;                                // absolute expiration time for the current event
        Notifier *m_nextEvent;                                  // next Nofifier event
        bool m_periodic;                                                // true if this is a periodic event
        bool m_queued;                                                  // indicates if this entry is queued
        SEM_ID m_handlerSemaphore;                              // held by interrupt manager task while handler call is in progress 
        DISALLOW_COPY_AND_ASSIGN(Notifier);
};

#endif