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/**
* @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>
typedef struct {
const Scheduler_Control *scheduler;
rtems_task_priority new_priority;
Priority_Control old_priority;
rtems_status_code status;
} RTEMS_tasks_Set_priority_context;
static bool _RTEMS_tasks_Set_priority_filter(
Thread_Control *the_thread,
Priority_Control *new_priority_p,
void *arg
)
{
RTEMS_tasks_Set_priority_context *context;
const Scheduler_Control *scheduler;
bool valid;
Priority_Control current_priority;
Priority_Control new_priority;
context = arg;
scheduler = _Scheduler_Get_own( the_thread );
current_priority = _Thread_Get_priority( the_thread );
context->scheduler = scheduler;
context->old_priority = current_priority;
new_priority = _RTEMS_Priority_To_core(
scheduler,
context->new_priority,
&valid
);
*new_priority_p = new_priority;
if ( !valid ) {
context->status = RTEMS_INVALID_PRIORITY;
return false;
}
the_thread->real_priority = new_priority;
context->status = STATUS_SUCCESSFUL;
return _Thread_Priority_less_than( current_priority, new_priority )
|| !_Thread_Owns_resources( the_thread );
}
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;
ISR_lock_Context lock_context;
const Scheduler_Control *scheduler;
Priority_Control old_priority;
rtems_status_code status;
if ( old_priority_p == NULL ) {
return RTEMS_INVALID_ADDRESS;
}
the_thread = _Thread_Get( id, &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
}
if ( new_priority != RTEMS_CURRENT_PRIORITY ) {
RTEMS_tasks_Set_priority_context context;
Per_CPU_Control *cpu_self;
cpu_self = _Thread_Dispatch_disable_critical( &lock_context );
_ISR_lock_ISR_enable( &lock_context );
context.new_priority = new_priority;
_Thread_Change_priority(
the_thread,
0,
&context,
_RTEMS_tasks_Set_priority_filter,
false
);
_Thread_Dispatch_enable( cpu_self );
scheduler = context.scheduler;
old_priority = context.old_priority;
status = context.status;
} else {
_Thread_State_acquire_critical( the_thread, &lock_context );
scheduler = _Scheduler_Get_own( the_thread );
old_priority = _Thread_Get_priority( the_thread );
_Thread_State_release( the_thread, &lock_context );
status = RTEMS_SUCCESSFUL;
}
*old_priority_p = _RTEMS_Priority_From_core( scheduler, old_priority );
return status;
}
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