/*
* Copyright 2015-2017, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* benchmark_time.cpp -- benchmark_time module definitions
*/
#include "benchmark_time.hpp"
#include "os.h"
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#define NSECPSEC 1000000000
/*
* benchmark_time_get -- get timestamp from clock source
*/
void
benchmark_time_get(benchmark_time_t *time)
{
os_clock_gettime(CLOCK_MONOTONIC, time);
}
/*
* benchmark_time_diff -- get time interval
*/
void
benchmark_time_diff(benchmark_time_t *d, benchmark_time_t *t1,
benchmark_time_t *t2)
{
long long nsecs = (t2->tv_sec - t1->tv_sec) * NSECPSEC + t2->tv_nsec -
t1->tv_nsec;
assert(nsecs >= 0);
d->tv_sec = nsecs / NSECPSEC;
d->tv_nsec = nsecs % NSECPSEC;
}
/*
* benchmark_time_get_secs -- get total number of seconds
*/
double
benchmark_time_get_secs(benchmark_time_t *t)
{
return (double)t->tv_sec + (double)t->tv_nsec / NSECPSEC;
}
/*
* benchmark_time_get_nsecs -- get total number of nanoseconds
*/
unsigned long long
benchmark_time_get_nsecs(benchmark_time_t *t)
{
unsigned long long ret = t->tv_nsec;
ret += t->tv_sec * NSECPSEC;
return ret;
}
/*
* benchmark_time_compare -- compare two moments in time
*/
int
benchmark_time_compare(const benchmark_time_t *t1, const benchmark_time_t *t2)
{
if (t1->tv_sec == t2->tv_sec)
return (int)((long long)t1->tv_nsec - (long long)t2->tv_nsec);
else
return (int)((long long)t1->tv_sec - (long long)t2->tv_sec);
}
/*
* benchmark_time_set -- set time using number of nanoseconds
*/
void
benchmark_time_set(benchmark_time_t *time, unsigned long long nsecs)
{
time->tv_sec = nsecs / NSECPSEC;
time->tv_nsec = nsecs % NSECPSEC;
}
/*
* number of samples used to calculate average time required to get a current
* time from the system
*/
#define N_PROBES_GET_TIME 10000000UL
/*
* benchmark_get_avg_get_time -- calculates average time required to get the
* current time from the system in nanoseconds
*/
unsigned long long
benchmark_get_avg_get_time(void)
{
benchmark_time_t time;
benchmark_time_t start;
benchmark_time_t stop;
benchmark_time_get(&start);
for (size_t i = 0; i < N_PROBES_GET_TIME; i++) {
benchmark_time_get(&time);
}
benchmark_time_get(&stop);
benchmark_time_diff(&time, &start, &stop);
unsigned long long avg =
benchmark_time_get_nsecs(&time) / N_PROBES_GET_TIME;
return avg;
}