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82 lines
2.4 KiB
C
82 lines
2.4 KiB
C
/* SPDX-License-Identifier: BSD-2-Clause */
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/**
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* @file
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*
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* @ingroup POSIXAPI
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*
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* @brief Function Returns the Resolution of any Clock
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*/
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/*
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* COPYRIGHT (c) 1989-2007.
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* On-Line Applications Research Corporation (OAR).
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <time.h>
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#include <errno.h>
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#include <rtems/score/todimpl.h>
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#include <rtems/config.h>
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#include <rtems/seterr.h>
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/*
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* 14.2.1 Clocks, P1003.1b-1993, p. 263
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*/
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int clock_getres(
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clockid_t clock_id,
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struct timespec *res
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)
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{
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if ( !res )
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rtems_set_errno_and_return_minus_one( EINVAL );
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switch ( clock_id ) {
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/*
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* All time in rtems is based on the same clock tick.
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*/
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case CLOCK_REALTIME:
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case CLOCK_PROCESS_CPUTIME_ID:
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case CLOCK_THREAD_CPUTIME_ID:
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if ( res ) {
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res->tv_sec = rtems_configuration_get_microseconds_per_tick() /
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TOD_MICROSECONDS_PER_SECOND;
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res->tv_nsec = rtems_configuration_get_nanoseconds_per_tick();
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}
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break;
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default:
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rtems_set_errno_and_return_minus_one( EINVAL );
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}
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return 0;
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}
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