MotorSafetyHelper.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 __MOTOR_SAFETY_HELPER__
#define __MOTOR_SAFETY_HELPER__

#include "ErrorBase.h"
#include "Synchronized.h"
#include <semLib.h>

class MotorSafety;

class MotorSafetyHelper : public ErrorBase
{
public:
        MotorSafetyHelper(MotorSafety *safeObject);
        ~MotorSafetyHelper();
        void Feed();
        void SetExpiration(float expirationTime);
        float GetExpiration();
        bool IsAlive();
        void Check();
        void SetSafetyEnabled(bool enabled);
        bool IsSafetyEnabled();
        static void CheckMotors();
private:
        double m_expiration;                    // the expiration time for this object
        bool m_enabled;                                 // true if motor safety is enabled for this motor
        double m_stopTime;                              // the FPGA clock value when this motor has expired
        ReentrantSemaphore m_syncMutex;                 // protect accesses to the state for this object
        MotorSafety *m_safeObject;              // the object that is using the helper
        MotorSafetyHelper *m_nextHelper; // next object in the list of MotorSafetyHelpers
        static MotorSafetyHelper *m_headHelper; // the head of the list of MotorSafetyHelper objects
        static ReentrantSemaphore m_listMutex;  // protect accesses to the list of helpers
};

#endif