EDF Scheduler

EDF Scheduler. More...

Files
file	scheduleredf.h
	Data Related to the Manipulation of Threads for the EDF Scheduler.
file	scheduleredfimpl.h
	EDF Scheduler Implementation.

Data Structures
struct	Scheduler_EDF_Context
struct	Scheduler_EDF_Node
	Scheduler node specialization for EDF schedulers. More...

Macros
#define	SCHEDULER_EDF_MAXIMUM_PRIORITY   INT_MAX
#define	SCHEDULER_EDF_ENTRY_POINTS
#define	SCHEDULER_EDF_PRIO_MSB   0x8000000000000000

Functions
void	_Scheduler_EDF_Initialize (const Scheduler_Control *scheduler)
	Initializes EDF scheduler. More...
void	_Scheduler_EDF_Block (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Removes the blocking thread from the ready queue and schedules is only again if the thread is executing or the heir thread. More...
void	_Scheduler_EDF_Schedule (const Scheduler_Control *scheduler, Thread_Control *the_thread)
	Sets the heir thread to be the next ready thread in the rbtree ready queue. More...
void	_Scheduler_EDF_Node_initialize (const Scheduler_Control *scheduler, Scheduler_Node *node, Thread_Control *the_thread, Priority_Control priority)
	Initializes an EDF specific scheduler node of the_thread. More...
void	_Scheduler_EDF_Unblock (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Performs an unblocking of the thread. More...
void	_Scheduler_EDF_Update_priority (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Updates the priority of the scheduler node. More...
Priority_Control	_Scheduler_EDF_Map_priority (const Scheduler_Control *scheduler, Priority_Control priority)
	Gets the mapped priority map of the priority control. More...
Priority_Control	_Scheduler_EDF_Unmap_priority (const Scheduler_Control *scheduler, Priority_Control priority)
	Gets the unmapped priority map of the priority control. More...
void	_Scheduler_EDF_Yield (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Executes a thread yield for the thread. More...
void	_Scheduler_EDF_Release_job (const Scheduler_Control *scheduler, Thread_Control *the_thread, Priority_Node *priority_node, uint64_t deadline, Thread_queue_Context *queue_context)
	Releases a EDF job. More...
void	_Scheduler_EDF_Cancel_job (const Scheduler_Control *scheduler, Thread_Control *the_thread, Priority_Node *priority_node, Thread_queue_Context *queue_context)
	Cancels a job and removes the thread from the queue context. More...
RTEMS_INLINE_ROUTINE Scheduler_EDF_Context *	_Scheduler_EDF_Get_context (const Scheduler_Control *scheduler)
	Gets the context of the scheduler. More...
RTEMS_INLINE_ROUTINE Scheduler_EDF_Node *	_Scheduler_EDF_Thread_get_node (Thread_Control *the_thread)
	Gets the scheduler EDF node of the thread. More...
RTEMS_INLINE_ROUTINE Scheduler_EDF_Node *	_Scheduler_EDF_Node_downcast (Scheduler_Node *node)
	Returns the scheduler EDF node for the scheduler node. More...
RTEMS_INLINE_ROUTINE bool	_Scheduler_EDF_Less (const void *left, const RBTree_Node *right)
	Checks if left is less than the priority of the node right. More...
RTEMS_INLINE_ROUTINE bool	_Scheduler_EDF_Priority_less_equal (const void *left, const RBTree_Node *right)
	Checks if left is less or equal than the priority of the node right. More...
RTEMS_INLINE_ROUTINE void	_Scheduler_EDF_Enqueue (Scheduler_EDF_Context *context, Scheduler_EDF_Node *node, Priority_Control insert_priority)
	Inserts the scheduler node with the given priority in the ready queue of the context. More...
RTEMS_INLINE_ROUTINE void	_Scheduler_EDF_Extract (Scheduler_EDF_Context *context, Scheduler_EDF_Node *node)
	Extracts the scheduler node from the ready queue of the context. More...
RTEMS_INLINE_ROUTINE void	_Scheduler_EDF_Extract_body (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Extracts the node from the context of the given scheduler. More...
RTEMS_INLINE_ROUTINE void	_Scheduler_EDF_Schedule_body (const Scheduler_Control *scheduler, Thread_Control *the_thread, bool force_dispatch)
	Schedules the next ready thread as the heir. More...

Detailed Description

EDF Scheduler.

Macro Definition Documentation

SCHEDULER_EDF_ENTRY_POINTS

#define SCHEDULER_EDF_ENTRY_POINTS

Value:

{ \
    _Scheduler_EDF_Initialize,       /* initialize entry point */ \
    _Scheduler_EDF_Schedule,         /* schedule entry point */ \
    _Scheduler_EDF_Yield,            /* yield entry point */ \
    _Scheduler_EDF_Block,            /* block entry point */ \
    _Scheduler_EDF_Unblock,          /* unblock entry point */ \
    _Scheduler_EDF_Update_priority,  /* update priority entry point */ \
    _Scheduler_EDF_Map_priority,     /* map priority entry point */ \
    _Scheduler_EDF_Unmap_priority,   /* unmap priority entry point */ \
    SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP \
    _Scheduler_EDF_Node_initialize,  /* node initialize entry point */ \
    _Scheduler_default_Node_destroy, /* node destroy entry point */ \
    _Scheduler_EDF_Release_job,      /* new period of task */ \
    _Scheduler_EDF_Cancel_job,       /* cancel period of task */ \
    _Scheduler_default_Tick,         /* tick entry point */ \
    _Scheduler_default_Start_idle    /* start idle entry point */ \
    SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY \
  }

Entry points for the Earliest Deadline First Scheduler.

SCHEDULER_EDF_PRIO_MSB

#define SCHEDULER_EDF_PRIO_MSB   0x8000000000000000

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 SCHEDULER_EDF_PRIO_MSB) from those ones who do not have any deadlines and thus are considered background tasks.

Function Documentation

_Scheduler_EDF_Block()

void _Scheduler_EDF_Block	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Removes the blocking thread from the ready queue and schedules is only again if the thread is executing or the heir thread.

Parameters

[in,out]	scheduler	The scheduler for the operation.
	the_thread	The thread to operate upon.
[in,out]	node	The scheduler node for this thread.

_Scheduler_EDF_Cancel_job()

void _Scheduler_EDF_Cancel_job	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Priority_Node *	priority_node,
		Thread_queue_Context *	queue_context
	)

Cancels a job and removes the thread from the queue context.

Parameters

	scheduler	The scheduler instance.
	the_thread	The thread for the operation.
[in,out]	priority_node	The corresponding priority node.
[in,out]	queue_context	The thread queue context.

_Scheduler_EDF_Enqueue()

RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Enqueue	(	Scheduler_EDF_Context *	context,
		Scheduler_EDF_Node *	node,
		Priority_Control	insert_priority
	)

Inserts the scheduler node with the given priority in the ready queue of the context.

Parameters

[in,out]	context	The context to insert the node in.
	node	The node to be inserted.
	insert_priority	The priority with which the node will be inserted.

_Scheduler_EDF_Extract()

RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Extract	(	Scheduler_EDF_Context *	context,
		Scheduler_EDF_Node *	node
	)

Extracts the scheduler node from the ready queue of the context.

Parameters

[in,out]	context	The context to extract the node from.
[in,out]	node	The node to extract.

_Scheduler_EDF_Extract_body()

RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Extract_body	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Extracts the node from the context of the given scheduler.

Parameters

	scheduler	The scheduler instance.
	the_thread	The thread is not used in this method.
[in,out]	node	The node to be extracted.

_Scheduler_EDF_Get_context()

RTEMS_INLINE_ROUTINE Scheduler_EDF_Context* _Scheduler_EDF_Get_context

(

const Scheduler_Control *

scheduler

)

Gets the context of the scheduler.

Parameters

scheduler

The scheduler instance.

Returns

The scheduler context of scheduler.

_Scheduler_EDF_Initialize()

void _Scheduler_EDF_Initialize

(

const Scheduler_Control *

scheduler

)

Initializes EDF scheduler.

This routine initializes the EDF scheduler.

Parameters

[in,out]

scheduler

The scheduler instance.

_Scheduler_EDF_Less()

RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Less	(	const void *	left,
		const RBTree_Node *	right
	)

Checks if left is less than the priority of the node right.

Parameters

left	The priority on the left hand side of the comparison.
right	The node of which the priority is compared to left.

Return values

true	left is less than the priority of right.
false	left is greater or equal than the priority of right.

_Scheduler_EDF_Map_priority()

Priority_Control _Scheduler_EDF_Map_priority	(	const Scheduler_Control *	scheduler,
		Priority_Control	priority
	)

Gets the mapped priority map of the priority control.

Parameters

scheduler	Not used in this operation.
priority	The priority control to get the priority map of.

Returns

The mapped priority map of priority.

_Scheduler_EDF_Node_downcast()

RTEMS_INLINE_ROUTINE Scheduler_EDF_Node* _Scheduler_EDF_Node_downcast

(

Scheduler_Node *

node

)

Returns the scheduler EDF node for the scheduler node.

Parameters

node	The scheduler node of which the scheduler EDF node is returned.

Returns

The corresponding scheduler EDF node.

_Scheduler_EDF_Node_initialize()

void _Scheduler_EDF_Node_initialize	(	const Scheduler_Control *	scheduler,
		Scheduler_Node *	node,
		Thread_Control *	the_thread,
		Priority_Control	priority
	)

Initializes an EDF specific scheduler node of the_thread.

Parameters

scheduler	The scheduler instance.
node	The node being initialized.
the_thread	The thread of the node.
priority	The thread priority.

_Scheduler_EDF_Priority_less_equal()

RTEMS_INLINE_ROUTINE bool _Scheduler_EDF_Priority_less_equal	(	const void *	left,
		const RBTree_Node *	right
	)

Checks if left is less or equal than the priority of the node right.

Parameters

left	The priority on the left hand side of the comparison.
right	The node of which the priority is compared to left.

Return values

true	left is less or equal than the priority of right.
false	left is greater than the priority of right.

_Scheduler_EDF_Release_job()

void _Scheduler_EDF_Release_job	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Priority_Node *	priority_node,
		uint64_t	deadline,
		Thread_queue_Context *	queue_context
	)

Releases a EDF job.

Parameters

	scheduler	The scheduler instance
	the_thread	The thread
[in,out]	priority_node	The priority node for the operation.
	deadline	The deadline for the job.
[in,out]	queue_context	The thread queue context.

_Scheduler_EDF_Schedule()

void _Scheduler_EDF_Schedule	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread
	)

Sets the heir thread to be the next ready thread in the rbtree ready queue.

This kernel routine sets the heir thread to be the next ready thread in the rbtree ready queue.

Parameters

[in,out]	scheduler	The scheduler instance.
	the_thread	The thread being scheduled.

_Scheduler_EDF_Schedule_body()

RTEMS_INLINE_ROUTINE void _Scheduler_EDF_Schedule_body	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		bool	force_dispatch
	)

Schedules the next ready thread as the heir.

Parameters

scheduler	The scheduler instance to schedule the minimum of the context of.
the_thread	This parameter is not used.
force_dispatch	Indicates whether the current heir is blocked even if it is not set as preemptible.

_Scheduler_EDF_Thread_get_node()

RTEMS_INLINE_ROUTINE Scheduler_EDF_Node* _Scheduler_EDF_Thread_get_node

(

Thread_Control *

the_thread

)

Gets the scheduler EDF node of the thread.

Parameters

the_thread

The thread to get the scheduler node of.

Returns

The EDF scheduler node of the_thread.

_Scheduler_EDF_Unblock()

void _Scheduler_EDF_Unblock	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Performs an unblocking of the thread.

Parameters

[in,out]	scheduler	The scheduler instance.
	the_thread	The unblocking thread. May be set as new heir.
[in,out]	node	The scheduler node for the thread.

_Scheduler_EDF_Unmap_priority()

Priority_Control _Scheduler_EDF_Unmap_priority	(	const Scheduler_Control *	scheduler,
		Priority_Control	priority
	)

Gets the unmapped priority map of the priority control.

Parameters

scheduler	Not used in this operation.
priority	The priority control to get the priority map of.

Returns

The unmapped priority map of priority.

_Scheduler_EDF_Update_priority()

void _Scheduler_EDF_Update_priority	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Updates the priority of the scheduler node.

Parameters

	scheduler	The scheduler instance.
	the_thread	The thread for the operation.
[in,out]	node	The priority node to update the priority of.

_Scheduler_EDF_Yield()

void _Scheduler_EDF_Yield	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Scheduler_Node *	node
	)

Executes a thread yield for the thread.

Parameters

[in,out]	scheduler	The scheduler instance.
	the_thread	The thread that performs the yield.
[in,out]	node	The scheduler node for this thread.