score/src/timespectoticks.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSScoreTimespec
0007  *
0008  * @brief This source file contains the implementation of
0009  *   _Timespec_To_ticks().
0010  */
0011
0012 /*
0013  *  COPYRIGHT (c) 1989-2007.
0014  *  On-Line Applications Research Corporation (OAR).
0015  *
0016  * Redistribution and use in source and binary forms, with or without
0017  * modification, are permitted provided that the following conditions
0018  * are met:
0019  * 1. Redistributions of source code must retain the above copyright
0020  *    notice, this list of conditions and the following disclaimer.
0021  * 2. Redistributions in binary form must reproduce the above copyright
0022  *    notice, this list of conditions and the following disclaimer in the
0023  *    documentation and/or other materials provided with the distribution.
0024  *
0025  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0026  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0027  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0028  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0029  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0030  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0031  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0032  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0033  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0034  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0035  * POSSIBILITY OF SUCH DAMAGE.
0036  */
0037
0038 #ifdef HAVE_CONFIG_H
0039 #include "config.h"
0040 #endif
0041
0042 #include <rtems/score/timespec.h>
0043 #include <rtems/score/todimpl.h>
0044 #include <rtems/config.h>
0045
0046 /**
0047  *
0048  *  This routines converts a timespec to the corresponding number of ticks.
0049  */
0050
0051 uint32_t _Timespec_To_ticks(
0052   const struct timespec *time
0053 )
0054 {
0055   uint32_t  ticks;
0056   uint32_t  nanoseconds_per_tick;
0057
0058   if ( (time->tv_sec == 0) && (time->tv_nsec == 0) )
0059     return 0;
0060
0061   /**
0062    *  We should ensure the ticks not be truncated by integer division.  We
0063    *  need to have it be greater than or equal to the requested time.  It
0064    *  should not be shorter.
0065    */
0066   ticks                 = time->tv_sec * TOD_TICKS_PER_SECOND;
0067   nanoseconds_per_tick  = rtems_configuration_get_nanoseconds_per_tick();
0068   ticks                += time->tv_nsec / nanoseconds_per_tick;
0069
0070   if ( (time->tv_nsec % nanoseconds_per_tick) != 0 )
0071     ticks += 1;
0072
0073   return ticks;
0074 }