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/*
* Copyright © 2014 - 2015 Collabora, Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef TIMESPEC_UTIL_H
#define TIMESPEC_UTIL_H
#include <stdint.h>
#include <assert.h>
#define NSEC_PER_SEC 1000000000
/* Subtract timespecs
*
* \param r[out] result: a - b
* \param a[in] operand
* \param b[in] operand
*/
static inline void
timespec_sub(struct timespec *r,
const struct timespec *a, const struct timespec *b)
{
r->tv_sec = a->tv_sec - b->tv_sec;
r->tv_nsec = a->tv_nsec - b->tv_nsec;
if (r->tv_nsec < 0) {
r->tv_sec--;
r->tv_nsec += NSEC_PER_SEC;
}
}
/* Convert timespec to nanoseconds
*
* \param a timespec
* \return nanoseconds
*/
static inline int64_t
timespec_to_nsec(const struct timespec *a)
{
return (int64_t)a->tv_sec * NSEC_PER_SEC + a->tv_nsec;
}
/* Convert milli-Hertz to nanoseconds
*
* \param mhz frequency in mHz, not zero
* \return period in nanoseconds
*/
static inline int64_t
millihz_to_nsec(uint32_t mhz)
{
assert(mhz > 0);
return 1000000000000LL / mhz;
}
#endif /* TIMESPEC_UTIL_H */
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