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/*
* adjustime() function - required by NTP
*
* I am unaware of the history behind the definition of this service
* and don't know if its behavior is covered by any standard. --joel
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <time.h>
#include <sys/time.h>
#include <rtems/system.h>
#include <rtems/score/tod.h>
#include <rtems/posix/time.h>
static long __adjustment = 0;
int adjtime ( struct timeval *delta, struct timeval *olddelta )
{
struct timespec ts;
if ( olddelta ) {
olddelta->tv_sec = __adjustment / TOD_MICROSECONDS_PER_SECOND;
olddelta->tv_usec = __adjustment / TOD_MICROSECONDS_PER_SECOND;
}
if ( !delta )
return -1;
__adjustment = (delta->tv_sec * TOD_MICROSECONDS_PER_SECOND) + delta->tv_usec;
/* too small to account for */
if ( __adjustment < _TOD_Microseconds_per_tick )
return 0;
clock_gettime( CLOCK_REALTIME, &ts );
ts.tv_sec += (__adjustment / TOD_MICROSECONDS_PER_SECOND);
ts.tv_nsec += (__adjustment % TOD_MICROSECONDS_PER_SECOND) *
TOD_NANOSECONDS_PER_MICROSECOND;
/* if adjustment is too much positive */
while ( ts.tv_nsec >= TOD_NANOSECONDS_PER_SECOND ) {
ts.tv_nsec -= TOD_NANOSECONDS_PER_SECOND;
ts.tv_sec++;
}
/* if adjustment is too much negative */
while ( ts.tv_nsec <= (-1 * TOD_NANOSECONDS_PER_SECOND) ) {
ts.tv_nsec += TOD_NANOSECONDS_PER_SECOND;
ts.tv_sec--;
}
clock_settime( CLOCK_REALTIME, &ts );
return 0;
}
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