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