Files
allwpilib/wpilibc/src/main/native/include/MotorSafetyHelper.h
Tyler Veness 8c680a26f8 Moved C++ comments from source files to headers (#1111)
Also sorted functions in C++ sources to match order in related headers.
2018-05-31 20:47:15 -07:00

126 lines
3.5 KiB
C++

/*----------------------------------------------------------------------------*/
/* Copyright (c) 2008-2018 FIRST. 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 the root directory of */
/* the project. */
/*----------------------------------------------------------------------------*/
#pragma once
#include <set>
#include <wpi/mutex.h>
#include "ErrorBase.h"
namespace frc {
class MotorSafety;
class MotorSafetyHelper : public ErrorBase {
public:
/**
* The constructor for a MotorSafetyHelper object.
*
* The helper object is constructed for every object that wants to implement
* the Motor Safety protocol. The helper object has the code to actually do
* the timing and call the motors Stop() method when the timeout expires. The
* motor object is expected to call the Feed() method whenever the motors
* value is updated.
*
* @param safeObject a pointer to the motor object implementing MotorSafety.
* This is used to call the Stop() method on the motor.
*/
explicit MotorSafetyHelper(MotorSafety* safeObject);
~MotorSafetyHelper();
/**
* Feed the motor safety object.
*
* Resets the timer on this object that is used to do the timeouts.
*/
void Feed();
/**
* Set the expiration time for the corresponding motor safety object.
*
* @param expirationTime The timeout value in seconds.
*/
void SetExpiration(double expirationTime);
/**
* Retrieve the timeout value for the corresponding motor safety object.
*
* @return the timeout value in seconds.
*/
double GetExpiration() const;
/**
* Determine if the motor is still operating or has timed out.
*
* @return a true value if the motor is still operating normally and hasn't
* timed out.
*/
bool IsAlive() const;
/**
* Check if this motor has exceeded its timeout.
*
* This method is called periodically to determine if this motor has exceeded
* its timeout value. If it has, the stop method is called, and the motor is
* shut down until its value is updated again.
*/
void Check();
/**
* Enable/disable motor safety for this device
*
* Turn on and off the motor safety option for this PWM object.
*
* @param enabled True if motor safety is enforced for this object
*/
void SetSafetyEnabled(bool enabled);
/**
* Return the state of the motor safety enabled flag
*
* Return if the motor safety is currently enabled for this devicce.
*
* @return True if motor safety is enforced for this device
*/
bool IsSafetyEnabled() const;
/**
* Check the motors to see if any have timed out.
*
* This static method is called periodically to poll all the motors and stop
* any that have timed out.
*/
static void CheckMotors();
private:
// The expiration time for this object
double m_expiration;
// True if motor safety is enabled for this motor
bool m_enabled;
// The FPGA clock value when this motor has expired
double m_stopTime;
// Protect accesses to the state for this object
mutable wpi::mutex m_thisMutex;
// The object that is using the helper
MotorSafety* m_safeObject;
// List of all existing MotorSafetyHelper objects.
static std::set<MotorSafetyHelper*> m_helperList;
// Protect accesses to the list of helpers
static wpi::mutex m_listMutex;
};
} // namespace frc