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