/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSScoreSchedulerDPS
*
* @brief This header file provides interfaces of the
* @ref RTEMSScoreSchedulerDPS which are only used by the implementation.
*/
/*
* Copyright (C) 2010 Gedare Bloom.
* Copyright (C) 2011 On-Line Applications Research Corporation (OAR).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#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 RTEMSScoreSchedulerDPS
*
* @{
*/
/**
* @brief Gets the context of the scheduler.
*
* @param scheduler The scheduler to get the context of.
*
* @return The context of the scheduler.
*/
RTEMS_INLINE_ROUTINE Scheduler_priority_Context *
_Scheduler_priority_Get_context( const Scheduler_Control *scheduler )
{
return (Scheduler_priority_Context *) _Scheduler_Get_context( scheduler );
}
/**
* @brief Gets the scheduler node of the thread.
*
* @param the_thread The thread to get the scheduler node of.
*
* @return The scheduler node of @a the_thread.
*/
RTEMS_INLINE_ROUTINE Scheduler_priority_Node *_Scheduler_priority_Thread_get_node(
Thread_Control *the_thread
)
{
return (Scheduler_priority_Node *) _Thread_Scheduler_get_home_node( the_thread );
}
/**
* @brief Gets the priority node of the scheduler node.
*
* @param node The node to get the priority node of.
*
* @return The priority node.
*/
RTEMS_INLINE_ROUTINE Scheduler_priority_Node *_Scheduler_priority_Node_downcast(
Scheduler_Node *node
)
{
return (Scheduler_priority_Node *) node;
}
/**
* @brief Ready queue initialization.
*
* This routine initializes @a ready_queues for priority-based scheduling.
*
* @param[out] ready_queues The ready queue to initialize.
* @param maximum_priority The maximum priority in the ready queue.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_initialize(
Chain_Control *ready_queues,
Priority_Control maximum_priority
)
{
size_t index;
for ( index = 0 ; index <= (size_t) maximum_priority ; ++index ) {
_Chain_Initialize_empty( &ready_queues[ index ] );
}
}
/**
* @brief Enqueues a node on the specified ready queue.
*
* The node is placed as the last element of its priority group.
*
* @param node The node to enqueue.
* @param[in, out] ready_queue The ready queue.
* @param[out] bit_map The priority bit map of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_enqueue(
Chain_Node *node,
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, node );
_Priority_bit_map_Add( bit_map, &ready_queue->Priority_map );
}
/**
* @brief Enqueues a node on the specified ready queue as first.
*
* The node is placed as the first element of its priority group.
*
* @param node The node to enqueue as first.
* @param[in, out] ready_queue The ready queue.
* @param[out] bit_map The priority bit map of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_enqueue_first(
Chain_Node *node,
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, node );
_Priority_bit_map_Add( bit_map, &ready_queue->Priority_map );
}
/**
* @brief Extracts a node from the specified ready queue.
*
* @param node The node to extract.
* @param[in, out] ready_queue The ready queue.
* @param[out] bit_map The priority bit map of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_extract(
Chain_Node *node,
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 );
_Chain_Initialize_node( node );
_Priority_bit_map_Remove( bit_map, &ready_queue->Priority_map );
} else {
_Chain_Extract_unprotected( node );
}
}
/**
* @brief Extracts a node from the context of the scheduler.
*
* @param scheduler The scheduler instance.
* @param the_thread The thread of which the node will be extracted.
* @param[in, out] The node which preserves the ready queue.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Extract_body(
const Scheduler_Control *scheduler,
Thread_Control *the_thread,
Scheduler_Node *node
)
{
Scheduler_priority_Context *context;
Scheduler_priority_Node *the_node;
context = _Scheduler_priority_Get_context( scheduler );
the_node = _Scheduler_priority_Node_downcast( node );
_Scheduler_priority_Ready_queue_extract(
&the_thread->Object.Node,
&the_node->Ready_queue,
&context->Bit_map
);
}
/**
* @brief Returns a pointer to the first node.
*
* This routines returns a pointer to the first node on @a ready_queues.
*
* @param bit_map The priority bit map of the scheduler instance.
* @param ready_queues The ready queues of the scheduler instance.
*
* @return This method returns the first node.
*/
RTEMS_INLINE_ROUTINE Chain_Node *_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 );
Chain_Node *first = _Chain_First( &ready_queues[ index ] );
_Assert( first != _Chain_Tail( &ready_queues[ index ] ) );
return first;
}
/**
* @brief Scheduling decision logic.
*
* This kernel routine implements scheduling decision logic
* for priority-based scheduling.
*
* @param[in, out] scheduler The scheduler instance.
* @param the_thread This parameter is unused.
* @param force_dispatch Indicates whether the dispatch happens also if
* the currently executing thread is set as not preemptible.
*/
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 = (Thread_Control *)
_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 new priority
* value.
*
* @param[in, out] ready_queue The ready queue.
* @param new_priority The new priority.
* @param bit_map The priority bit map of the scheduler instance.
* @param ready_queues The ready queues of the scheduler instance.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_priority_Ready_queue_update(
Scheduler_priority_Ready_queue *ready_queue,
unsigned int new_priority,
Priority_bit_map_Control *bit_map,
Chain_Control *ready_queues
)
{
ready_queue->current_priority = new_priority;
ready_queue->ready_chain = &ready_queues[ new_priority ];
_Priority_bit_map_Initialize_information(
bit_map,
&ready_queue->Priority_map,
new_priority
);
}
/** @} */
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
