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- /****************************************************************************
- * sched/clock/clock_time2ticks.c
- *
- * Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. 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.
- * 3. Neither the name NuttX 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <stdint.h>
- #include <time.h>
- #include "clock/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
- }
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