rtems/src/tasksetscheduler.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_scheduler().
0010  */
0011
0012 /*
0013  * Copyright (c) 2014 embedded brains GmbH & Co. KG
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  *
0024  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0025  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0027  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0028  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0029  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0030  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0031  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0032  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0033  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0034  * POSSIBILITY OF SUCH DAMAGE.
0035  */
0036
0037 #ifdef HAVE_CONFIG_H
0038 #include "config.h"
0039 #endif
0040
0041 #include <rtems/rtems/tasksimpl.h>
0042 #include <rtems/rtems/statusimpl.h>
0043 #include <rtems/score/schedulerimpl.h>
0044
0045 rtems_status_code rtems_task_set_scheduler(
0046   rtems_id            task_id,
0047   rtems_id            scheduler_id,
0048   rtems_task_priority priority
0049 )
0050 {
0051   const Scheduler_Control *scheduler;
0052   Thread_Control          *the_thread;
0053   Thread_queue_Context     queue_context;
0054   ISR_lock_Context         state_context;
0055   Per_CPU_Control         *cpu_self;
0056   bool                     valid;
0057   Priority_Control         core_priority;
0058   Status_Control           status;
0059
0060   scheduler = _Scheduler_Get_by_id( scheduler_id );
0061   if ( scheduler == NULL ) {
0062     return RTEMS_INVALID_ID;
0063   }
0064
0065   core_priority = _RTEMS_Priority_To_core( scheduler, priority, &valid );
0066   if ( !valid ) {
0067     return RTEMS_INVALID_PRIORITY;
0068   }
0069
0070   _Thread_queue_Context_initialize( &queue_context );
0071   the_thread = _Thread_Get( task_id, &queue_context.Lock_context.Lock_context );
0072
0073   if ( the_thread == NULL ) {
0074 #if defined(RTEMS_MULTIPROCESSING)
0075     if ( _Thread_MP_Is_remote( task_id ) ) {
0076       return RTEMS_ILLEGAL_ON_REMOTE_OBJECT;
0077     }
0078 #endif
0079
0080     return RTEMS_INVALID_ID;
0081   }
0082
0083   cpu_self = _Thread_queue_Dispatch_disable( &queue_context );
0084   _Thread_Wait_acquire_critical( the_thread, &queue_context );
0085   _Thread_State_acquire_critical( the_thread, &state_context );
0086
0087   status = _Scheduler_Set( scheduler, the_thread, core_priority );
0088
0089   _Thread_State_release_critical( the_thread, &state_context );
0090   _Thread_Wait_release( the_thread, &queue_context );
0091   _Thread_Dispatch_enable( cpu_self );
0092   return _Status_Get( status );
0093 }