timer_get.c
1.79 KB
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/**
* \file
*
* \author Georg Hopp
*
* \copyright
* Copyright © 2014 Georg Hopp
*
* 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
* (at your option) 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/>.
*/
#define _POSIX_C_SOURCE 199309L
#include <time.h>
#include <limits.h>
#include "trbase.h"
unsigned long
TR_timerGet(TR_Timer this, unsigned long * missed)
{
struct timespec now;
unsigned long long elapsed;
unsigned long sec_factor;
long nan_factor;
unsigned long _missed;
clock_gettime(CLOCK_REALTIME, &now);
switch (this->base) {
case TR_TBASE_NAN:
sec_factor = 1000 * 1000 * 1000;
break;
case TR_TBASE_MIC:
sec_factor = 1000 * 1000;
break;
default:
case TR_TBASE_MIL:
sec_factor = 1000;
break;
case TR_TBASE_SEC:
sec_factor = 1;
break;
}
nan_factor = 1000 * 1000 * 1000 / sec_factor;
elapsed = (now.tv_sec - this->sec) * sec_factor
+ (now.tv_nsec - this->nsec) / nan_factor;
_missed = elapsed / this->timeout;
if (_missed) {
this->sec += _missed * this->timeout * sec_factor / nan_factor;
this->nsec += _missed * this->timeout * sec_factor % nan_factor;
if (missed) *missed = _missed;
} else {
if (missed) *missed = 0;
}
return this->timeout - (elapsed % this->timeout);
}
// vim: set ts=4 sw=4: