/**
* @file
*
* @ingroup RTEMSScoreSchedulerEDF
*
* @brief EDF Scheduler Implementation
*/
/*
* Copryight (c) 2011 Petr Benes.
* 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_SCHEDULEREDFIMPL_H
#define _RTEMS_SCORE_SCHEDULEREDFIMPL_H
#include <rtems/score/scheduleredf.h>
#include <rtems/score/schedulerimpl.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @addtogroup RTEMSScoreSchedulerEDF
*
* @{
*/
/**
* This is just a most significant bit of Priority_Control type. It
* distinguishes threads which are deadline driven (priority
* represented by a lower number than @a SCHEDULER_EDF_PRIO_MSB) from those
* ones who do not have any deadlines and thus are considered background
* tasks.
*/
#define SCHEDULER_EDF_PRIO_MSB 0x8000000000000000
/**
* @brief Gets the context of the scheduler.
*
* @param scheduler The scheduler instance.
*
* @return The scheduler context of @a scheduler.
*/
RTEMS_INLINE_ROUTINE Scheduler_EDF_Context *
_Scheduler_EDF_Get_context( const Scheduler_Control *scheduler )
{
return (Scheduler_EDF_Context *) _Scheduler_Get_context( scheduler );
}
/**
* @brief Gets the scheduler EDF node of the thread.
*
* @param the_thread The thread to get the scheduler node of.
*
* @return The EDF scheduler node of @a the_thread.
*/
RTEMS_INLINE_ROUTINE Scheduler_EDF_Node *_Scheduler_EDF_Thread_get_node(
Thread_Control *the_thread
)
{
return (Scheduler_EDF_Node *) _Thread_Scheduler_get_home_node( the_thread );
}
/**
* @brief Returns the scheduler EDF node for the scheduler node.
*
* @param node The scheduler node of which the scheduler EDF node is returned.
*
* @return The corresponding scheduler EDF node.
*/
RTEMS_INLINE_ROUTINE Scheduler_EDF_Node * _Scheduler_EDF_Node_downcast(
Scheduler_Node *node
)
{
return (Scheduler_EDF_Node *) node;
}
/**
* @brief Checks if @a left is less than the priority of the node @a right.
*
* @param left The priority on the left hand side of the comparison.
* @param right The node of which the priority is compared to left.
*
* @retval true @a left is less than the priority of @a right.
* @retval false @a left is greater or equal than the priority of @a right.
*/
RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Less(
const void *left,
const RBTree_Node *right
)
{
const Priority_Control *the_left;
const Scheduler_EDF_Node *the_right;
Priority_Control prio_left;
Priority_Control prio_right;
the_left = left;
the_right = RTEMS_CONTAINER_OF( right, Scheduler_EDF_Node, Node );
prio_left = *the_left;
prio_right = the_right->priority;
return prio_left < prio_right;
}
/**
* @brief Checks if @a left is less or equal than the priority of the node @a right.
*
* @param left The priority on the left hand side of the comparison.
* @param right The node of which the priority is compared to left.
*
* @retval true @a left is less or equal than the priority of @a right.
* @retval false @a left is greater than the priority of @a right.
*/
RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Priority_less_equal(
const void *left,
const RBTree_Node *right
)
{
const Priority_Control *the_left;
const Scheduler_EDF_Node *the_right;
Priority_Control prio_left;
Priority_Control prio_right;
the_left = left;
the_right = RTEMS_CONTAINER_OF( right, Scheduler_EDF_Node, Node );
prio_left = *the_left;
prio_right = the_right->priority;
return prio_left <= prio_right;
}
/**
* @brief Inserts the scheduler node with the given priority in the ready
* queue of the context.
*
* @param[in, out] context The context to insert the node in.
* @param node The node to be inserted.
* @param insert_priority The priority with which the node will be inserted.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Enqueue(
Scheduler_EDF_Context *context,
Scheduler_EDF_Node *node,
Priority_Control insert_priority
)
{
_RBTree_Insert_inline(
&context->Ready,
&node->Node,
&insert_priority,
_Scheduler_EDF_Priority_less_equal
);
}
/**
* @brief Extracts the scheduler node from the ready queue of the context.
*
* @param[in, out] context The context to extract the node from.
* @param[in, out] node The node to extract.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Extract(
Scheduler_EDF_Context *context,
Scheduler_EDF_Node *node
)
{
_RBTree_Extract( &context->Ready, &node->Node );
}
/**
* @brief Extracts the node from the context of the given scheduler.
*
* @param scheduler The scheduler instance.
* @param the_thread The thread is not used in this method.
* @param[in, out] node The node to be extracted.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Extract_body(
const Scheduler_Control *scheduler,
Thread_Control *the_thread,
Scheduler_Node *node
)
{
Scheduler_EDF_Context *context;
Scheduler_EDF_Node *the_node;
context = _Scheduler_EDF_Get_context( scheduler );
the_node = _Scheduler_EDF_Node_downcast( node );
_Scheduler_EDF_Extract( context, the_node );
}
/**
* @brief Schedules the next ready thread as the heir.
*
* @param scheduler The scheduler instance to schedule the minimum of the context of.
* @param the_thread This parameter is not used.
* @param force_dispatch Indicates whether the current heir is blocked even if it is
* not set as preemptible.
*/
RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Schedule_body(
const Scheduler_Control *scheduler,
Thread_Control *the_thread,
bool force_dispatch
)
{
Scheduler_EDF_Context *context;
RBTree_Node *first;
Scheduler_EDF_Node *node;
(void) the_thread;
context = _Scheduler_EDF_Get_context( scheduler );
first = _RBTree_Minimum( &context->Ready );
node = RTEMS_CONTAINER_OF( first, Scheduler_EDF_Node, Node );
_Scheduler_Update_heir( node->Base.owner, force_dispatch );
}
/** @} */
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
