posix/src/sched_rr_get_interval.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Limits for Scheduling Parameter
0009  */
0010
0011 /*
0012  *  13.3.6 Get Scheduling Parameter Limits, P1003.1b-1993, p. 258
0013  *
0014  *  COPYRIGHT (c) 1989-2007.
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 <unistd.h> /* getpid */
0044 #include <sched.h>
0045 #include <errno.h>
0046
0047 #include <rtems/score/timespec.h>
0048 #include <rtems/config.h>
0049 #include <rtems/seterr.h>
0050
0051 int sched_rr_get_interval(
0052   pid_t             pid,
0053   struct timespec  *interval
0054 )
0055 {
0056   /*
0057    *  Only supported for the "calling process" (i.e. this node).
0058    */
0059
0060   if ( pid && pid != getpid() )
0061     rtems_set_errno_and_return_minus_one( ESRCH );
0062
0063   if ( !interval )
0064     rtems_set_errno_and_return_minus_one( EINVAL );
0065
0066   _Timespec_From_ticks(
0067     rtems_configuration_get_ticks_per_timeslice(),
0068     interval
0069   );
0070
0071   return 0;
0072 }