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/**
* @file
*
* @brief Function Returns the Resolution of any Clock
* @ingroup POSIXAPI
*/
/*
* COPYRIGHT (c) 1989-2007.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <time.h>
#include <errno.h>
#include <rtems/score/todimpl.h>
#include <rtems/config.h>
#include <rtems/seterr.h>
/*
* 14.2.1 Clocks, P1003.1b-1993, p. 263
*/
int clock_getres(
clockid_t clock_id,
struct timespec *res
)
{
if ( !res )
rtems_set_errno_and_return_minus_one( EINVAL );
switch ( clock_id ) {
/*
* All time in rtems is based on the same clock tick.
*/
case CLOCK_REALTIME:
case CLOCK_PROCESS_CPUTIME_ID:
case CLOCK_THREAD_CPUTIME_ID:
if ( res ) {
res->tv_sec = rtems_configuration_get_microseconds_per_tick() /
TOD_MICROSECONDS_PER_SECOND;
res->tv_nsec = rtems_configuration_get_nanoseconds_per_tick();
}
break;
default:
rtems_set_errno_and_return_minus_one( EINVAL );
}
return 0;
}
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