// license:BSD-3-Clause // copyright-holders:Aaron Giles /**************************************************************************/ /** * @file attotime.h * Support functions for working with attotime data. * @defgroup ATTOTIME * @{ * Support functions for working with attotime data. * * @class attotime * Attotime is an attosecond-accurate timing system implemented as * 96-bit integers. * * 1 second = 1e0 seconds * 1 millisecond = 1e-3 seconds * 1 microsecond = 1e-6 seconds * 1 nanosecond = 1e-9 seconds * 1 picosecond = 1e-12 seconds * 1 femtosecond = 1e-15 seconds * 1 attosecond = 1e-18 seconds * * This may seem insanely accurate, but it has its uses when multiple * clocks in the system are run by independent crystals. It is also * useful to compute the attotime for something small, say 1 clock tick, * and still have it be accurate and useful for scaling. * * Attotime consists of a 32-bit seconds count and a 64-bit attoseconds * count. Because the lower bits are kept as attoseconds and not as a * full 64-bit value, there is headroom to make some operations simpler. */ /**************************************************************************/ #pragma once #ifndef __ATTOTIME_H__ #define __ATTOTIME_H__ #include #undef min #undef max //************************************************************************** // CONSTANTS //************************************************************************** // core components of the attotime structure typedef INT64 attoseconds_t; typedef INT32 seconds_t; // core definitions const attoseconds_t ATTOSECONDS_PER_SECOND_SQRT = 1000000000; const attoseconds_t ATTOSECONDS_PER_SECOND = ATTOSECONDS_PER_SECOND_SQRT * ATTOSECONDS_PER_SECOND_SQRT; const attoseconds_t ATTOSECONDS_PER_MILLISECOND = ATTOSECONDS_PER_SECOND / 1000; const attoseconds_t ATTOSECONDS_PER_MICROSECOND = ATTOSECONDS_PER_SECOND / 1000000; const attoseconds_t ATTOSECONDS_PER_NANOSECOND = ATTOSECONDS_PER_SECOND / 1000000000; const seconds_t ATTOTIME_MAX_SECONDS = 1000000000; //************************************************************************** // MACROS //************************************************************************** // convert between a double and attoseconds #define ATTOSECONDS_TO_DOUBLE(x) ((double)(x) * 1e-18) #define DOUBLE_TO_ATTOSECONDS(x) ((attoseconds_t)((x) * 1e18)) // convert between hertz (as a double) and attoseconds #define ATTOSECONDS_TO_HZ(x) ((double)ATTOSECONDS_PER_SECOND / (double)(x)) #define HZ_TO_ATTOSECONDS(x) ((attoseconds_t)(ATTOSECONDS_PER_SECOND / (x))) // macros for converting other seconds types to attoseconds #define ATTOSECONDS_IN_SEC(x) ((attoseconds_t)(x) * ATTOSECONDS_PER_SECOND) #define ATTOSECONDS_IN_MSEC(x) ((attoseconds_t)(x) * ATTOSECONDS_PER_MILLISECOND) #define ATTOSECONDS_IN_USEC(x) ((attoseconds_t)(x) * ATTOSECONDS_PER_MICROSECOND) #define ATTOSECONDS_IN_NSEC(x) ((attoseconds_t)(x) * ATTOSECONDS_PER_NANOSECOND) //************************************************************************** // TYPE DEFINITIONS //***************************************************************************/ // the attotime structure itself class attotime { public: // construction/destruction attotime() : m_seconds(0), m_attoseconds(0) { } /** Constructs with @p secs seconds and @p attos attoseconds. */ attotime(seconds_t secs, attoseconds_t attos) : m_seconds(secs), m_attoseconds(attos) { } attotime(const attotime& that) : m_seconds(that.m_seconds), m_attoseconds(that.m_attoseconds) { } // assignment attotime& operator=(const attotime& that) { this->m_seconds = that.m_seconds; this->m_attoseconds = that.m_attoseconds; return *this; } // queries bool is_zero() const { return (m_seconds == 0 && m_attoseconds == 0); } /** Test if value is above @ref ATTOTIME_MAX_SECONDS (considered an overflow) */ bool is_never() const { return (m_seconds >= ATTOTIME_MAX_SECONDS); } // conversion to other forms double as_double() const { return double(m_seconds) + ATTOSECONDS_TO_DOUBLE(m_attoseconds); } attoseconds_t as_attoseconds() const; UINT64 as_ticks(UINT32 frequency) const; /** Convert to string using at @p precision */ const char *as_string(int precision = 9) const; /** @return the attoseconds portion. */ attoseconds_t attoseconds() const { return m_attoseconds; } /** @return the seconds portion. */ seconds_t seconds() const { return m_seconds; } static attotime from_double(double _time); static attotime from_ticks(UINT64 ticks, UINT32 frequency); /** Create an attotime from a integer count of seconds @seconds */ static attotime from_seconds(INT32 seconds) { return attotime(seconds, 0); } /** Create an attotime from a integer count of milliseconds @msec */ static attotime from_msec(INT64 msec) { return attotime(msec / 1000, (msec % 1000) * (ATTOSECONDS_PER_SECOND / 1000)); } /** Create an attotime from a integer count of microseconds @usec */ static attotime from_usec(INT64 usec) { return attotime(usec / 1000000, (usec % 1000000) * (ATTOSECONDS_PER_SECOND / 1000000)); } /** Create an attotime from a integer count of nanoseconds @nsec */ static attotime from_nsec(INT64 nsec) { return attotime(nsec / 1000000000, (nsec % 1000000000) * (ATTOSECONDS_PER_SECOND / 1000000000)); } /** Create an attotime from at the given frequency @frequency */ static attotime from_hz(double frequency) { assert(frequency > 0); double d = 1 / frequency; return attotime(floor(d), modf(d, &d) * ATTOSECONDS_PER_SECOND); } // math attotime &operator+=(const attotime &right); attotime &operator-=(const attotime &right); attotime &operator*=(UINT32 factor); attotime &operator/=(UINT32 factor); // members seconds_t m_seconds; attoseconds_t m_attoseconds; // constants static const attotime never; static const attotime zero; }; /** @} */ //************************************************************************** // INLINE FUNCTIONS //************************************************************************** /** handle addition between two attotimes */ inline attotime operator+(const attotime &left, const attotime &right) { attotime result; // if one of the items is never, return never if (left.m_seconds >= ATTOTIME_MAX_SECONDS || right.m_seconds >= ATTOTIME_MAX_SECONDS) return attotime::never; // add the seconds and attoseconds result.m_attoseconds = left.m_attoseconds + right.m_attoseconds; result.m_seconds = left.m_seconds + right.m_seconds; // normalize and return if (result.m_attoseconds >= ATTOSECONDS_PER_SECOND) { result.m_attoseconds -= ATTOSECONDS_PER_SECOND; result.m_seconds++; } // overflow if (result.m_seconds >= ATTOTIME_MAX_SECONDS) return attotime::never; return result; } inline attotime &attotime::operator+=(const attotime &right) { // if one of the items is never, return never if (this->m_seconds >= ATTOTIME_MAX_SECONDS || right.m_seconds >= ATTOTIME_MAX_SECONDS) return *this = never; // add the seconds and attoseconds m_attoseconds += right.m_attoseconds; m_seconds += right.m_seconds; // normalize and return if (this->m_attoseconds >= ATTOSECONDS_PER_SECOND) { this->m_attoseconds -= ATTOSECONDS_PER_SECOND; this->m_seconds++; } // overflow if (this->m_seconds >= ATTOTIME_MAX_SECONDS) return *this = never; return *this; } /** handle subtraction between two attotimes */ inline attotime operator-(const attotime &left, const attotime &right) { attotime result; // if time1 is never, return never if (left.m_seconds >= ATTOTIME_MAX_SECONDS) return attotime::never; // add the seconds and attoseconds result.m_attoseconds = left.m_attoseconds - right.m_attoseconds; result.m_seconds = left.m_seconds - right.m_seconds; // normalize and return if (result.m_attoseconds < 0) { result.m_attoseconds += ATTOSECONDS_PER_SECOND; result.m_seconds--; } return result; } inline attotime &attotime::operator-=(const attotime &right) { // if time1 is never, return never if (this->m_seconds >= ATTOTIME_MAX_SECONDS) return *this = never; // add the seconds and attoseconds m_attoseconds -= right.m_attoseconds; m_seconds -= right.m_seconds; // normalize and return if (this->m_attoseconds < 0) { this->m_attoseconds += ATTOSECONDS_PER_SECOND; this->m_seconds--; } return *this; } /** handle multiplication by an integral factor; defined in terms of the assignment operators */ inline attotime operator*(const attotime &left, UINT32 factor) { attotime result = left; result *= factor; return result; } inline attotime operator*(UINT32 factor, const attotime &right) { attotime result = right; result *= factor; return result; } /** handle division by an integral factor; defined in terms of the assignment operators */ inline attotime operator/(const attotime &left, UINT32 factor) { attotime result = left; result /= factor; return result; } /** handle comparisons between attotimes */ inline bool operator==(const attotime &left, const attotime &right) { return (left.m_seconds == right.m_seconds && left.m_attoseconds == right.m_attoseconds); } inline bool operator!=(const attotime &left, const attotime &right) { return (left.m_seconds != right.m_seconds || left.m_attoseconds != right.m_attoseconds); } inline bool operator<(const attotime &left, const attotime &right) { return (left.m_seconds < right.m_seconds || (left.m_seconds == right.m_seconds && left.m_attoseconds < right.m_attoseconds)); } inline bool operator<=(const attotime &left, const attotime &right) { return (left.m_seconds < right.m_seconds || (left.m_seconds == right.m_seconds && left.m_attoseconds <= right.m_attoseconds)); } inline bool operator>(const attotime &left, const attotime &right) { return (left.m_seconds > right.m_seconds || (left.m_seconds == right.m_seconds && left.m_attoseconds > right.m_attoseconds)); } inline bool operator>=(const attotime &left, const attotime &right) { return (left.m_seconds > right.m_seconds || (left.m_seconds == right.m_seconds && left.m_attoseconds >= right.m_attoseconds)); } //------------------------------------------------- // min - return the minimum of two attotimes //------------------------------------------------- inline attotime min(const attotime &left, const attotime &right) { if (left.m_seconds > right.m_seconds) return right; if (left.m_seconds < right.m_seconds) return left; if (left.m_attoseconds > right.m_attoseconds) return right; return left; } //------------------------------------------------- // max - return the maximum of two attotimes //------------------------------------------------- inline attotime max(const attotime &left, const attotime &right) { if (left.m_seconds > right.m_seconds) return left; if (left.m_seconds < right.m_seconds) return right; if (left.m_attoseconds > right.m_attoseconds) return left; return right; } /** Convert to an attoseconds value, clamping to +/- 1 second */ inline attoseconds_t attotime::as_attoseconds() const { // positive values between 0 and 1 second if (m_seconds == 0) return m_attoseconds; // negative values between -1 and 0 seconds else if (m_seconds == -1) return m_attoseconds - ATTOSECONDS_PER_SECOND; // out-of-range positive values else if (m_seconds > 0) return ATTOSECONDS_PER_SECOND; // out-of-range negative values else return -ATTOSECONDS_PER_SECOND; } /** as_ticks - convert to ticks at @p frequency */ inline UINT64 attotime::as_ticks(UINT32 frequency) const { UINT32 fracticks = (attotime(0, m_attoseconds) * frequency).m_seconds; return mulu_32x32(m_seconds, frequency) + fracticks; } /** Create an attotime from a tick count @ticks at the given frequency @frequency */ inline attotime attotime::from_ticks(UINT64 ticks, UINT32 frequency) { attoseconds_t attos_per_tick = HZ_TO_ATTOSECONDS(frequency); if (ticks < frequency) return attotime(0, ticks * attos_per_tick); UINT32 remainder; INT32 secs = divu_64x32_rem(ticks, frequency, &remainder); return attotime(secs, (UINT64)remainder * attos_per_tick); } /** Create an attotime from floating point count of seconds @p _time */ inline attotime attotime::from_double(double _time) { seconds_t secs = floor(_time); _time -= double(secs); attoseconds_t attos = DOUBLE_TO_ATTOSECONDS(_time); return attotime(secs, attos); } #endif // __ATTOTIME_H__