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/**
* @file
*
* @ingroup POSIXAPI
*
* @brief Function Fetches State of POSIX Per-Process Timers
*/
/*
* 14.2.4 Per-Process Timers, P1003.1b-1993, p. 267
*
* COPYRIGHT (c) 1989-2008.
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <time.h>
#include <errno.h>
#include <rtems/posix/timerimpl.h>
#include <rtems/score/todimpl.h>
#include <rtems/score/watchdogimpl.h>
#include <rtems/seterr.h>
#include <rtems/timespec.h>
/*
* - When a timer is initialized, the value of the time in
* that moment is stored.
* - When this function is called, it returns the difference
* between the current time and the initialization time.
*/
int timer_gettime(
timer_t timerid,
struct itimerspec *value
)
{
POSIX_Timer_Control *ptimer;
ISR_lock_Context lock_context;
Per_CPU_Control *cpu;
struct timespec now;
struct timespec expire;
struct timespec result;
if ( !value )
rtems_set_errno_and_return_minus_one( EINVAL );
ptimer = _POSIX_Timer_Get( timerid, &lock_context );
if ( ptimer == NULL ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
cpu = _POSIX_Timer_Acquire_critical( ptimer, &lock_context );
rtems_timespec_from_ticks( ptimer->Timer.expire, &expire );
if ( ptimer->clock_type == CLOCK_MONOTONIC ) {
_Timecounter_Nanouptime(&now);
} else if (ptimer->clock_type == CLOCK_REALTIME) {
_TOD_Get(&now);
} else {
_POSIX_Timer_Release( cpu, &lock_context );
rtems_set_errno_and_return_minus_one( EINVAL );
}
if ( rtems_timespec_less_than( &now, &expire ) ) {
rtems_timespec_subtract( &now, &expire, &result );
} else {
result.tv_nsec = 0;
result.tv_sec = 0;
}
value->it_value = result;
value->it_interval = ptimer->timer_data.it_interval;
_POSIX_Timer_Release( cpu, &lock_context );
return 0;
}
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