/**
* @file
*
* @brief RTEMS Set Task Priority
* @ingroup ClassicTasks
*/
/*
* COPYRIGHT (c) 1989-2014.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/rtems/tasksimpl.h>
#include <rtems/score/schedulerimpl.h>
#include <rtems/score/threadimpl.h>
static rtems_status_code _RTEMS_tasks_Set_priority(
Thread_Control *the_thread,
const Scheduler_Control *scheduler,
Priority_Control new_priority,
Thread_queue_Context *queue_context
)
{
Priority_Control core_new_priority;
bool valid;
Per_CPU_Control *cpu_self;
core_new_priority = _RTEMS_Priority_To_core(
scheduler,
new_priority,
&valid
);
if ( !valid ) {
_Thread_Wait_release( the_thread, queue_context );
return RTEMS_INVALID_PRIORITY;
}
_Thread_Priority_change(
the_thread,
&the_thread->Real_priority,
core_new_priority,
false,
queue_context
);
cpu_self = _Thread_queue_Dispatch_disable( queue_context );
_Thread_Wait_release( the_thread, queue_context );
_Thread_Priority_update( queue_context );
_Thread_Dispatch_enable( cpu_self );
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_task_set_priority(
rtems_id id,
rtems_task_priority new_priority,
rtems_task_priority *old_priority_p
)
{
Thread_Control *the_thread;
Thread_queue_Context queue_context;
const Scheduler_Control *scheduler;
Priority_Control old_priority;
rtems_status_code status;
if ( old_priority_p == NULL ) {
return RTEMS_INVALID_ADDRESS;
}
_Thread_queue_Context_initialize( &queue_context );
_Thread_queue_Context_clear_priority_updates( &queue_context );
the_thread = _Thread_Get( id, &queue_context.Lock_context.Lock_context );
if ( the_thread == NULL ) {
#if defined(RTEMS_MULTIPROCESSING)
return _RTEMS_tasks_MP_Set_priority( id, new_priority, old_priority_p );
#else
return RTEMS_INVALID_ID;
#endif
}
_Thread_Wait_acquire_critical( the_thread, &queue_context );
scheduler = _Thread_Scheduler_get_home( the_thread );
old_priority = _Thread_Get_priority( the_thread );
if ( new_priority != RTEMS_CURRENT_PRIORITY ) {
status = _RTEMS_tasks_Set_priority(
the_thread,
scheduler,
new_priority,
&queue_context
);
} else {
_Thread_Wait_release( the_thread, &queue_context );
status = RTEMS_SUCCESSFUL;
}
*old_priority_p = _RTEMS_Priority_From_core( scheduler, old_priority );
return status;
}