2015-07-09 07:22:48 +03:00

61 lines
1.7 KiB
C++

/*
* System clock driver interface.
* Copyright (C) 2014 Pavel Kirienko <pavel.kirienko@gmail.com>
*/
#ifndef UAVCAN_DRIVER_SYSTEM_CLOCK_HPP_INCLUDED
#define UAVCAN_DRIVER_SYSTEM_CLOCK_HPP_INCLUDED
#include <uavcan/std.hpp>
#include <uavcan/build_config.hpp>
#include <uavcan/time.hpp>
namespace uavcan
{
/**
* System clock interface - monotonic and UTC.
*/
class UAVCAN_EXPORT ISystemClock
{
public:
virtual ~ISystemClock() { }
/**
* Monototic system clock.
*
* This clock shall never jump or change rate; the base time is irrelevant.
* This clock is mandatory and must remain functional at all times.
*
* On POSIX systems use clock_gettime() with CLOCK_MONOTONIC.
*/
virtual MonotonicTime getMonotonic() const = 0;
/**
* Global network clock.
* It doesn't have to be UTC, the name is a bit misleading - actual time base doesn't matter.
*
* This clock can be synchronized with other nodes on the bus, hence it can jump and/or change
* rate occasionally.
* This clock is optional; if it is not supported, return zero. Also return zero if the UTC time
* is not available yet (e.g. the device has just started up with no battery clock).
*
* For POSIX refer to clock_gettime(), gettimeofday().
*/
virtual UtcTime getUtc() const = 0;
/**
* Adjust the network-synchronized clock.
* Refer to @ref getUtc() for details.
*
* For POSIX refer to adjtime(), settimeofday().
*
* @param [in] adjustment Amount of time to add to the clock value.
*/
virtual void adjustUtc(UtcDuration adjustment) = 0;
};
}
#endif // UAVCAN_DRIVER_SYSTEM_CLOCK_HPP_INCLUDED