posix/src/pthreadgetschedparam.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Gets Scheduling Policy and Parameters of Individual Threads
0009  */
0010
0011 /*
0012  *  13.5.2 Dynamic Thread Scheduling Parameters Access,
0013  *         P1003.1c/Draft 10, p. 124
0014  *
0015  *  COPYRIGHT (c) 1989-2014.
0016  *  On-Line Applications Research Corporation (OAR).
0017  *
0018  * Redistribution and use in source and binary forms, with or without
0019  * modification, are permitted provided that the following conditions
0020  * are met:
0021  * 1. Redistributions of source code must retain the above copyright
0022  *    notice, this list of conditions and the following disclaimer.
0023  * 2. Redistributions in binary form must reproduce the above copyright
0024  *    notice, this list of conditions and the following disclaimer in the
0025  *    documentation and/or other materials provided with the distribution.
0026  *
0027  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0028  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0029  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0030  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0031  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0032  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0033  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0034  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0035  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0036  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0037  * POSSIBILITY OF SUCH DAMAGE.
0038  */
0039
0040 #ifdef HAVE_CONFIG_H
0041 #include "config.h"
0042 #endif
0043
0044 #include <pthread.h>
0045 #include <errno.h>
0046
0047 #include <rtems/posix/pthreadimpl.h>
0048 #include <rtems/posix/pthreadattrimpl.h>
0049 #include <rtems/posix/priorityimpl.h>
0050 #include <rtems/score/threadimpl.h>
0051
0052 int pthread_getschedparam(
0053   pthread_t           thread,
0054   int                *policy,
0055   struct sched_param *param
0056 )
0057 {
0058   Thread_Control                     *the_thread;
0059   Thread_queue_Context                queue_context;
0060   const Thread_CPU_budget_operations *cpu_budget_operations;
0061   const Scheduler_Control            *scheduler;
0062   Priority_Control                    priority;
0063
0064   if ( policy == NULL || param == NULL ) {
0065     return EINVAL;
0066   }
0067
0068   _Thread_queue_Context_initialize( &queue_context );
0069   the_thread = _Thread_Get( thread, &queue_context.Lock_context.Lock_context );
0070
0071   if ( the_thread == NULL ) {
0072     return ESRCH;
0073   }
0074
0075   _Thread_Wait_acquire_critical( the_thread, &queue_context );
0076
0077   scheduler = _Thread_Scheduler_get_home( the_thread );
0078   _POSIX_Threads_Get_sched_param_sporadic( the_thread, scheduler, param );
0079   priority = the_thread->Real_priority.priority;
0080   cpu_budget_operations = the_thread->CPU_budget.operations;
0081
0082   _Thread_Wait_release( the_thread, &queue_context );
0083
0084   param->sched_priority = _POSIX_Priority_From_core( scheduler, priority );
0085   *policy = _POSIX_Thread_Translate_to_sched_policy( cpu_budget_operations );
0086   return 0;
0087 }