posix/src/timergettime.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Function Fetches State of POSIX Per-Process Timers
0009  */
0010
0011 /*
0012  *  14.2.4 Per-Process Timers, P1003.1b-1993, p. 267
0013  *
0014  *  COPYRIGHT (c) 1989-2008.
0015  *  On-Line Applications Research Corporation (OAR).
0016  *
0017  * Redistribution and use in source and binary forms, with or without
0018  * modification, are permitted provided that the following conditions
0019  * are met:
0020  * 1. Redistributions of source code must retain the above copyright
0021  *    notice, this list of conditions and the following disclaimer.
0022  * 2. Redistributions in binary form must reproduce the above copyright
0023  *    notice, this list of conditions and the following disclaimer in the
0024  *    documentation and/or other materials provided with the distribution.
0025  *
0026  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0027  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0028  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0029  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0030  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0031  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0032  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0033  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0034  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0035  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0036  * POSSIBILITY OF SUCH DAMAGE.
0037  */
0038
0039 #ifdef HAVE_CONFIG_H
0040 #include "config.h"
0041 #endif
0042
0043 #include <time.h>
0044 #include <errno.h>
0045
0046 #include <rtems/posix/timerimpl.h>
0047 #include <rtems/score/todimpl.h>
0048 #include <rtems/score/watchdogimpl.h>
0049 #include <rtems/seterr.h>
0050 #include <rtems/timespec.h>
0051
0052 /*
0053  *          - When a timer is initialized, the value of the time in
0054  *            that moment is stored.
0055  *          - When this function is called, it returns the difference
0056  *            between the current time and the initialization time.
0057  */
0058
0059 int timer_gettime(
0060   timer_t            timerid,
0061   struct itimerspec *value
0062 )
0063 {
0064   POSIX_Timer_Control *ptimer;
0065   ISR_lock_Context lock_context;
0066   Per_CPU_Control *cpu;
0067   struct timespec now;
0068   struct timespec expire;
0069   struct timespec result;
0070
0071   if ( !value )
0072     rtems_set_errno_and_return_minus_one( EINVAL );
0073
0074   ptimer = _POSIX_Timer_Get( timerid, &lock_context );
0075   if ( ptimer == NULL ) {
0076     rtems_set_errno_and_return_minus_one( EINVAL );
0077   }
0078
0079   cpu = _POSIX_Timer_Acquire_critical( ptimer, &lock_context );
0080   rtems_timespec_from_ticks( ptimer->Timer.expire, &expire );
0081
0082   if ( ptimer->clock_type == CLOCK_MONOTONIC ) {
0083   _Timecounter_Nanouptime(&now);
0084   } else  if (ptimer->clock_type == CLOCK_REALTIME) {
0085     _TOD_Get(&now);
0086   } else {
0087     _POSIX_Timer_Release( cpu, &lock_context );
0088     rtems_set_errno_and_return_minus_one( EINVAL );
0089   }
0090
0091
0092  if ( rtems_timespec_less_than( &now, &expire ) ) {
0093       rtems_timespec_subtract( &now, &expire, &result );
0094   } else {
0095     result.tv_nsec = 0;
0096     result.tv_sec  = 0;
0097   }
0098
0099   value->it_value = result;
0100   value->it_interval = ptimer->timer_data.it_interval;
0101
0102   _POSIX_Timer_Release( cpu, &lock_context );
0103   return 0;
0104 }