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CANopenNode/stack/socketCAN/main_utils.c
2015-09-05 18:53:43 +02:00

90 lines
2.9 KiB
C

/*
* Different utilities for using CANopenNode tasks from mainline.
*
* @file main_utils.c
* @author Janez Paternoster
* @copyright 2015 Janez Paternoster
*
* This file is part of CANopenNode, an opensource CANopen Stack.
* Project home page is <http://canopennode.sourceforge.net>.
* For more information on CANopen see <http://www.can-cia.org/>.
*
* CANopenNode is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "main_utils.h"
/******************************************************************************/
int taskTmr_init(taskTmr_t *tt, long intervalns, uint16_t *maxTime){
int ret;
ret = tt->fd = timerfd_create(CLOCK_MONOTONIC, 0);
/* Prepare timer (one shot, each time calculate new expiration time) It is
* necessary not to use tt->tmrSpec.it_interval, because it is sliding. */
tt->tmrSpec.it_interval.tv_sec = 0;
tt->tmrSpec.it_interval.tv_nsec = 0;
tt->tmrVal = &tt->tmrSpec.it_value;
if(ret != -1){
ret = clock_gettime(CLOCK_MONOTONIC, tt->tmrVal);
}
if(ret != -1){
ret = timerfd_settime(tt->fd, TFD_TIMER_ABSTIME, &tt->tmrSpec, NULL);
}
tt->intervalns = intervalns;
tt->intervalus = (int16_t)(intervalns / 1000);
tt->maxTime = maxTime;
return ret;
}
int taskTmr_wait(taskTmr_t *tt, struct timespec *sync){
uint64_t tmrExp;
int ret = 0;
/* Wait for timer to expire */
if(read(tt->fd, &tmrExp, sizeof(tmrExp)) != sizeof(uint64_t)) ret = -1;
/* Calculate maximum interval in microseconds (informative) */
if(tt->maxTime != NULL){
struct timespec tmrMeasure;
if(clock_gettime(CLOCK_MONOTONIC, &tmrMeasure) == -1) ret = -1;
if(tmrMeasure.tv_sec == tt->tmrVal->tv_sec){
long dt = tmrMeasure.tv_nsec - tt->tmrVal->tv_nsec;
dt /= 1000;
dt += tt->intervalus;
if(dt > 0xFFFF){
*tt->maxTime = 0xFFFF;
}else if(dt > *tt->maxTime){
*tt->maxTime = (uint16_t) dt;
}
}
}
/* Calculate next shot for the timer */
tt->tmrVal->tv_nsec += tt->intervalns;
if(tt->tmrVal->tv_nsec >= NSEC_PER_SEC){
tt->tmrVal->tv_nsec -= NSEC_PER_SEC;
tt->tmrVal->tv_sec++;
}
if(timerfd_settime(tt->fd, TFD_TIMER_ABSTIME, &tt->tmrSpec, NULL) == -1) ret = -1;
return ret;
}