1
0
Fork 0
mirror of https://git.rwth-aachen.de/acs/public/villas/node/ synced 2025-03-09 00:00:00 +01:00
VILLASnode/lib/timing.c

131 lines
No EOL
2.8 KiB
C

/** Time related functions.
*
* @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
* @copyright 2017, Institute for Automation of Complex Power Systems, EONERC
* @license GNU General Public License (version 3)
*
* VILLASnode
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************************/
#include <unistd.h>
#include <sys/timerfd.h>
#include "timing.h"
int timerfd_create_rate(double rate)
{
int fd, ret;
struct timespec ts = time_from_double(1 / rate);
struct itimerspec its = {
.it_interval = ts,
.it_value = ts
};
fd = timerfd_create(CLOCK_MONOTONIC, 0);
if (fd < 0)
return fd;
ret = timerfd_settime(fd, 0, &its, NULL);
if (ret)
return ret;
return fd;
}
uint64_t timerfd_wait(int fd)
{
uint64_t runs;
return read(fd, &runs, sizeof(runs)) < 0 ? 0 : runs;
}
uint64_t timerfd_wait_until(int fd, const struct timespec *until)
{
int ret;
struct itimerspec its = {
.it_value = *until,
.it_interval = { 0, 0 }
};
ret = timerfd_settime(fd, TFD_TIMER_ABSTIME, &its, NULL);
if (ret)
return 0;
return timerfd_wait(fd);
}
struct timespec time_now()
{
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
return ts;
}
struct timespec time_add(const struct timespec *start, const struct timespec *end)
{
struct timespec sum = {
.tv_sec = end->tv_sec + start->tv_sec,
.tv_nsec = end->tv_nsec + start->tv_nsec
};
if (sum.tv_nsec >= 1000000000) {
sum.tv_sec += 1;
sum.tv_nsec -= 1000000000;
}
return sum;
}
struct timespec time_diff(const struct timespec *start, const struct timespec *end)
{
struct timespec diff = {
.tv_sec = end->tv_sec - start->tv_sec,
.tv_nsec = end->tv_nsec - start->tv_nsec
};
if (diff.tv_nsec < 0) {
diff.tv_sec -= 1;
diff.tv_nsec += 1000000000;
}
return diff;
}
struct timespec time_from_double(double secs)
{
struct timespec ts;
ts.tv_sec = secs;
ts.tv_nsec = 1.0e9 * (secs - ts.tv_sec);
return ts;
}
double time_to_double(const struct timespec *ts)
{
return ts->tv_sec + ts->tv_nsec * 1e-9;
}
double time_delta(const struct timespec *start, const struct timespec *end)
{
struct timespec diff = time_diff(start, end);
return time_to_double(&diff);
}