rtems/src/tasksetpriority.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSImplClassicTask
0007  *
0008  * @brief This source file contains the implementation of
0009  *   rtems_task_set_priority().
0010  */
0011
0012 /*
0013  *  COPYRIGHT (c) 1989-2014.
0014  *  On-Line Applications Research Corporation (OAR).
0015  *
0016  * Redistribution and use in source and binary forms, with or without
0017  * modification, are permitted provided that the following conditions
0018  * are met:
0019  * 1. Redistributions of source code must retain the above copyright
0020  *    notice, this list of conditions and the following disclaimer.
0021  * 2. Redistributions in binary form must reproduce the above copyright
0022  *    notice, this list of conditions and the following disclaimer in the
0023  *    documentation and/or other materials provided with the distribution.
0024  *
0025  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0026  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0027  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0028  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0029  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0030  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0031  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0032  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0033  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0034  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0035  * POSSIBILITY OF SUCH DAMAGE.
0036  */
0037
0038 #ifdef HAVE_CONFIG_H
0039 #include "config.h"
0040 #endif
0041
0042 #include <rtems/rtems/tasksimpl.h>
0043 #include <rtems/score/schedulerimpl.h>
0044 #include <rtems/score/threadimpl.h>
0045
0046 static rtems_status_code _RTEMS_tasks_Set_priority(
0047   Thread_Control          *the_thread,
0048   const Scheduler_Control *scheduler,
0049   Priority_Control         new_priority,
0050   Thread_queue_Context    *queue_context
0051 )
0052 {
0053   Priority_Control core_new_priority;
0054   bool             valid;
0055   Per_CPU_Control *cpu_self;
0056
0057   core_new_priority = _RTEMS_Priority_To_core(
0058     scheduler,
0059     new_priority,
0060     &valid
0061   );
0062
0063   if ( !valid ) {
0064     _Thread_Wait_release( the_thread, queue_context );
0065     return RTEMS_INVALID_PRIORITY;
0066   }
0067
0068   _Thread_Priority_change(
0069     the_thread,
0070     &the_thread->Real_priority,
0071     core_new_priority,
0072     PRIORITY_GROUP_LAST,
0073     queue_context
0074   );
0075   cpu_self = _Thread_queue_Dispatch_disable( queue_context );
0076   _Thread_Wait_release( the_thread, queue_context );
0077   _Thread_Priority_update( queue_context );
0078   _Thread_Dispatch_enable( cpu_self );
0079   return RTEMS_SUCCESSFUL;
0080 }
0081
0082 rtems_status_code rtems_task_set_priority(
0083   rtems_id             id,
0084   rtems_task_priority  new_priority,
0085   rtems_task_priority *old_priority_p
0086 )
0087 {
0088   Thread_Control          *the_thread;
0089   Thread_queue_Context     queue_context;
0090   const Scheduler_Control *scheduler;
0091   Priority_Control         old_priority;
0092   rtems_status_code        status;
0093
0094   if ( old_priority_p == NULL ) {
0095     return RTEMS_INVALID_ADDRESS;
0096   }
0097
0098   _Thread_queue_Context_initialize( &queue_context );
0099   _Thread_queue_Context_clear_priority_updates( &queue_context );
0100   the_thread = _Thread_Get( id, &queue_context.Lock_context.Lock_context );
0101
0102   if ( the_thread == NULL ) {
0103 #if defined(RTEMS_MULTIPROCESSING)
0104     return _RTEMS_tasks_MP_Set_priority( id, new_priority, old_priority_p );
0105 #else
0106     return RTEMS_INVALID_ID;
0107 #endif
0108   }
0109
0110   _Thread_Wait_acquire_critical( the_thread, &queue_context );
0111
0112   scheduler = _Thread_Scheduler_get_home( the_thread );
0113   old_priority = _Thread_Get_priority( the_thread );
0114
0115   if ( new_priority != RTEMS_CURRENT_PRIORITY ) {
0116     status = _RTEMS_tasks_Set_priority(
0117       the_thread,
0118       scheduler,
0119       new_priority,
0120       &queue_context
0121     );
0122   } else {
0123     _Thread_Wait_release( the_thread, &queue_context );
0124     status = RTEMS_SUCCESSFUL;
0125   }
0126
0127   *old_priority_p = _RTEMS_Priority_From_core( scheduler, old_priority );
0128   return status;
0129 }