104 lines
3.5 KiB
C
104 lines
3.5 KiB
C
/****************************************************************************
|
|
* libs/libc/sched/clock_time2ticks.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdint.h>
|
|
#include <time.h>
|
|
#include <assert.h>
|
|
|
|
#include <nuttx/clock.h>
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: clock_time2ticks
|
|
*
|
|
* Description:
|
|
* Convert a timespec delay to system timer ticks. This function is
|
|
* suitable for calculating relative time delays and does not depend on
|
|
* the other clock_* logic.
|
|
*
|
|
* Input Parameters:
|
|
* reltime - Convert this relative time to system clock ticks.
|
|
* ticks - Return the converted number of ticks here.
|
|
*
|
|
* Returned Value:
|
|
* Always returns OK
|
|
*
|
|
* Assumptions:
|
|
*
|
|
****************************************************************************/
|
|
|
|
int clock_time2ticks(FAR const struct timespec *reltime,
|
|
FAR sclock_t *ticks)
|
|
{
|
|
#ifdef CONFIG_HAVE_LONG_LONG
|
|
int64_t relnsec;
|
|
|
|
/* Convert the relative time into nanoseconds. The range of the int64_t
|
|
* is sufficiently large that there is no real need for range checking.
|
|
*/
|
|
|
|
relnsec = (int64_t)reltime->tv_sec * NSEC_PER_SEC +
|
|
(int64_t)reltime->tv_nsec;
|
|
|
|
/* Convert nanoseconds to clock ticks, rounding up to the smallest integer
|
|
* that is greater than or equal to the exact number of tick.
|
|
*/
|
|
|
|
*ticks = (sclock_t)((relnsec + NSEC_PER_TICK - 1) / NSEC_PER_TICK);
|
|
return OK;
|
|
#else
|
|
int32_t relusec;
|
|
|
|
/* This function uses an int32_t to only the relative time in microseconds.
|
|
* that means that the maximum supported relative time is 2,147,487.647
|
|
* seconds
|
|
*/
|
|
|
|
#if 0 // overkill
|
|
DEBUGASSERT(reltime->tv_sec < 2147487 ||
|
|
reltime->tv_sec == 2147487 &&
|
|
reltime->tv_nsec <= 647 * NSEC_PER_MSEC);
|
|
#endif
|
|
|
|
/* Convert the relative time into microseconds, rounding up to the smallest
|
|
* value that is greater than or equal to the exact number of microseconds.
|
|
*/
|
|
|
|
relusec = reltime->tv_sec * USEC_PER_SEC +
|
|
(reltime->tv_nsec + NSEC_PER_USEC - 1) / NSEC_PER_USEC;
|
|
|
|
/* Convert microseconds to clock ticks, rounding up to the smallest integer
|
|
* that is greater than or equal to the exact number of tick.
|
|
*/
|
|
|
|
*ticks = (sclock_t)((relusec + USEC_PER_TICK - 1) / USEC_PER_TICK);
|
|
return OK;
|
|
#endif
|
|
}
|