/**
* @file
*
* @brief Inlined Routines Associated with the Manipulation of the
* Priority-Based Scheduling Structures
*
* This inline file contains all of the inlined routines associated with
* the manipulation of the priority-based scheduling structures.
*/
/*
* Copyright (C) 2010 Gedare Bloom.
* Copyright (C) 2011 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.
*/
#ifndef _RTEMS_SCORE_SCHEDULERPRIORITYIMPL_H
#define _RTEMS_SCORE_SCHEDULERPRIORITYIMPL_H
#include <rtems/score/schedulerpriority.h>
#include <rtems/score/chainimpl.h>
#include <rtems/score/prioritybitmapimpl.h>
#include <rtems/score/schedulerimpl.h>
#include <rtems/score/thread.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @addtogroup ScoreSchedulerDPS
*/
/**@{**/
RTEMS_INLINE_ROUTINE Scheduler_priority_Context *
_Scheduler_priority_Get_context( const Scheduler_Control *scheduler )
{
return (Scheduler_priority_Context *) scheduler->context;
}
RTEMS_INLINE_ROUTINE Scheduler_priority_Node *_Scheduler_priority_Node_get(
Thread_Control *the_thread
)
{
return (Scheduler_priority_Node *) _Scheduler_Node_get( the_thread );
}
/**
* @brief Ready queue initialization.
*
* This routine initializes @a ready_queues for priority-based scheduling.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_initialize(
Chain_Control *ready_queues
)
{
size_t index;
/* initialize ready queue structures */
for( index=0; index <= PRIORITY_MAXIMUM; index++)
_Chain_Initialize_empty( &ready_queues[index] );
}
RTEMS_INLINE_ROUTINE Scheduler_priority_Node *
_Scheduler_priority_Get_scheduler_info( Thread_Control *thread )
{
return ( Scheduler_priority_Node * ) thread->scheduler_node;
}
/**
* @brief Enqueues a thread on the specified ready queue.
*
* The thread is placed as the last element of its priority group.
*
* @param[in] the_thread The thread to enqueue.
* @param[in] ready_queue The ready queue.
* @param[in] bit_map The priority bit map of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_enqueue(
Thread_Control *the_thread,
Scheduler_priority_Ready_queue *ready_queue,
Priority_bit_map_Control *bit_map
)
{
Chain_Control *ready_chain = ready_queue->ready_chain;
_Chain_Append_unprotected( ready_chain, &the_thread->Object.Node );
_Priority_bit_map_Add( bit_map, &ready_queue->Priority_map );
}
/**
* @brief Enqueues a thread on the specified ready queue as first.
*
* The thread is placed as the first element of its priority group.
*
* @param[in] the_thread The thread to enqueue as first.
* @param[in] ready_queue The ready queue.
* @param[in] bit_map The priority bit map of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_enqueue_first(
Thread_Control *the_thread,
Scheduler_priority_Ready_queue *ready_queue,
Priority_bit_map_Control *bit_map
)
{
Chain_Control *ready_chain = ready_queue->ready_chain;
_Chain_Prepend_unprotected( ready_chain, &the_thread->Object.Node );
_Priority_bit_map_Add( bit_map, &ready_queue->Priority_map );
}
/**
* @brief Extracts a thread from the specified ready queue.
*
* @param[in] the_thread The thread to extract.
* @param[in] ready_queue The ready queue.
* @param[in] bit_map The priority bit map of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_extract(
Thread_Control *the_thread,
Scheduler_priority_Ready_queue *ready_queue,
Priority_bit_map_Control *bit_map
)
{
Chain_Control *ready_chain = ready_queue->ready_chain;
if ( _Chain_Has_only_one_node( ready_chain ) ) {
_Chain_Initialize_empty( ready_chain );
_Priority_bit_map_Remove( bit_map, &ready_queue->Priority_map );
} else {
_Chain_Extract_unprotected( &the_thread->Object.Node );
}
}
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Extract_body(
const Scheduler_Control *scheduler,
Thread_Control *the_thread
)
{
Scheduler_priority_Context *context =
_Scheduler_priority_Get_context( scheduler );
Scheduler_priority_Node *node = _Scheduler_priority_Node_get( the_thread );
_Scheduler_priority_Ready_queue_extract(
the_thread,
&node->Ready_queue,
&context->Bit_map
);
}
/**
* @brief Return a pointer to the first thread.
*
* This routines returns a pointer to the first thread on @a ready_queues.
*
* @param[in] bit_map The priority bit map of the scheduler instance.
* @param[in] ready_queues The ready queues of the scheduler instance.
*
* @return This method returns the first thread or NULL
*/
RTEMS_INLINE_ROUTINE Thread_Control *_Scheduler_priority_Ready_queue_first(
Priority_bit_map_Control *bit_map,
Chain_Control *ready_queues
)
{
Priority_Control index = _Priority_bit_map_Get_highest( bit_map );
return (Thread_Control *) _Chain_First( &ready_queues[ index ] );
}
/**
* @brief Requeues a thread on the specified ready queue.
*
* This routine is invoked when a thread changes priority and should be
* moved to a different position on the ready queue.
*
* @param[in] the_thread The thread to requeue.
* @param[in] ready_queue The ready queue.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_requeue(
Thread_Control *the_thread,
Scheduler_priority_Ready_queue *ready_queue
)
{
Chain_Control *ready_chain = ready_queue->ready_chain;
if ( !_Chain_Has_only_one_node( ready_chain ) ) {
_Chain_Extract_unprotected( &the_thread->Object.Node );
_Chain_Append_unprotected( ready_chain, &the_thread->Object.Node );
}
}
/**
* @brief Scheduling decision logic.
*
* This kernel routine implements scheduling decision logic
* for priority-based scheduling.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Schedule_body(
const Scheduler_Control *scheduler,
Thread_Control *the_thread,
bool force_dispatch
)
{
Scheduler_priority_Context *context =
_Scheduler_priority_Get_context( scheduler );
Thread_Control *heir = _Scheduler_priority_Ready_queue_first(
&context->Bit_map,
&context->Ready[ 0 ]
);
( void ) the_thread;
_Scheduler_Update_heir( heir, force_dispatch );
}
/**
* @brief Updates the specified ready queue data according to the current
* priority of the thread.
*
* @param[in] the_thread The thread.
* @param[in] ready_queue The ready queue.
* @param[in] bit_map The priority bit map of the scheduler instance.
* @param[in] ready_queues The ready queues of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_update(
Thread_Control *the_thread,
Scheduler_priority_Ready_queue *ready_queue,
Priority_bit_map_Control *bit_map,
Chain_Control *ready_queues
)
{
Priority_Control priority = the_thread->current_priority;
ready_queue->ready_chain = &ready_queues[ priority ];
_Priority_bit_map_Initialize_information(
bit_map,
&ready_queue->Priority_map,
priority
);
}
/**
* @brief Priority comparison.
*
* This routine implements priority comparison for priority-based
* scheduling.
*
* @return >0 for higher priority, 0 for equal and <0 for lower priority.
*/
RTEMS_INLINE_ROUTINE int _Scheduler_priority_Priority_compare_body(
Priority_Control p1,
Priority_Control p2
)
{
/* High priority in priority scheduler is represented by low numbers. */
return ( p2 - p1 );
}
/** @} */
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
