Constant Bandwidth Server (CBS) Scheduler

This group contains the Constant Bandwidth Server (CBS) Scheduler implementation. More...

Files
file	cpukit/include/rtems/score/schedulercbs.h
	This header file provides interfaces of the Constant Bandwidth Server (CBS) Scheduler which are used by the implementation and the Application Configuration.
file	cpukit/include/rtems/score/schedulercbsimpl.h
	This header file provides interfaces of the Constant Bandwidth Server (CBS) Scheduler which are only used by the implementation.
file	cpukit/score/src/schedulercbs.c
	This source file contains the implementation of _Scheduler_CBS_Budget_callout() and _Scheduler_CBS_Initialize().
file	cpukit/score/src/schedulercbsattachthread.c
	This source file contains the implementation of _Scheduler_CBS_Attach_thread().
file	cpukit/score/src/schedulercbscleanup.c
	This source file contains the implementation of _Scheduler_CBS_Cleanup().
file	cpukit/score/src/schedulercbscreateserver.c
	This source file contains the implementation of _Scheduler_CBS_Create_server().
file	cpukit/score/src/schedulercbsdestroyserver.c
	This source file contains the implementation of _Scheduler_CBS_Destroy_server().
file	cpukit/score/src/schedulercbsdetachthread.c
	This source file contains the implementation of _Scheduler_CBS_Detach_thread().
file	cpukit/score/src/schedulercbsgetapprovedbudget.c
	This source file contains the implementation of _Scheduler_CBS_Get_approved_budget().
file	cpukit/score/src/schedulercbsgetexecutiontime.c
	This source file contains the implementation of _Scheduler_CBS_Get_execution_time().
file	cpukit/score/src/schedulercbsgetparameters.c
	This source file contains the implementation of _Scheduler_CBS_Get_parameters().
file	cpukit/score/src/schedulercbsgetremainingbudget.c
	This source file contains the implementation of _Scheduler_CBS_Get_remaining_budget().
file	cpukit/score/src/schedulercbsgetserverid.c
	This source file contains the implementation of _Scheduler_CBS_Get_server_id().
file	cpukit/score/src/schedulercbsnodeinit.c
	This source file contains the implementation of _Scheduler_CBS_Node_initialize().
file	cpukit/score/src/schedulercbsreleasejob.c
	This source file contains the implementation of _Scheduler_CBS_Release_job().
file	cpukit/score/src/schedulercbssetparameters.c
	This source file contains the implementation of _Scheduler_CBS_Set_parameters().
file	cpukit/score/src/schedulercbsunblock.c
	This source file contains the implementation of _Scheduler_CBS_Unblock().

Data Structures
struct	Scheduler_CBS_Parameters
struct	Scheduler_CBS_Server
struct	Scheduler_CBS_Node

Macros
#define	SCHEDULER_CBS_MAXIMUM_PRIORITY   SCHEDULER_EDF_MAXIMUM_PRIORITY
#define	SCHEDULER_CBS_ENTRY_POINTS
#define	SCHEDULER_CBS_OK   0
#define	SCHEDULER_CBS_ERROR_GENERIC   -16
#define	SCHEDULER_CBS_ERROR_NO_MEMORY   -17
#define	SCHEDULER_CBS_ERROR_INVALID_PARAMETER   -18
#define	SCHEDULER_CBS_ERROR_UNAUTHORIZED   -19
#define	SCHEDULER_CBS_ERROR_UNIMPLEMENTED   -20
#define	SCHEDULER_CBS_ERROR_MISSING_COMPONENT   -21
#define	SCHEDULER_CBS_ERROR_INCONSISTENT_STATE   -22
#define	SCHEDULER_CBS_ERROR_SYSTEM_OVERLOAD   -23
#define	SCHEDULER_CBS_ERROR_INTERNAL_ERROR   -24
#define	SCHEDULER_CBS_ERROR_NOT_FOUND   -25
#define	SCHEDULER_CBS_ERROR_FULL   -26
#define	SCHEDULER_CBS_ERROR_EMPTY   -27
#define	SCHEDULER_CBS_ERROR_NOSERVER   SCHEDULER_CBS_ERROR_NOT_FOUND

Typedefs
typedef uint32_t	Scheduler_CBS_Server_id
typedef void(*)	Scheduler_CBS_Budget_overrun(Scheduler_CBS_Server_id server_id)

Functions
void	_Scheduler_CBS_Unblock (const Scheduler_Control *scheduler, Thread_Control *the_thread, Scheduler_Node *node)
	Unblocks a thread.
void	_Scheduler_CBS_Release_job (const Scheduler_Control *scheduler, Thread_Control *the_thread, Priority_Node *priority_node, uint64_t deadline, Thread_queue_Context *queue_context)
	Releases a job.
void	_Scheduler_CBS_Cancel_job (const Scheduler_Control *scheduler, Thread_Control *the_thread, Priority_Node *priority_node, Thread_queue_Context *queue_context)
	Cancels a job.
int	_Scheduler_CBS_Initialize (void)
	_Scheduler_CBS_Initialize
int	_Scheduler_CBS_Attach_thread (Scheduler_CBS_Server_id server_id, rtems_id task_id)
	Attaches a task to an already existing server.
int	_Scheduler_CBS_Detach_thread (Scheduler_CBS_Server_id server_id, rtems_id task_id)
	Detaches from the CBS Server.
int	_Scheduler_CBS_Cleanup (void)
	Cleans up resources associated to the CBS Library.
int	_Scheduler_CBS_Create_server (Scheduler_CBS_Parameters *params, Scheduler_CBS_Budget_overrun budget_overrun_callback, rtems_id *server_id)
	Creates a new server with specified parameters.
int	_Scheduler_CBS_Destroy_server (Scheduler_CBS_Server_id server_id)
	Detaches all tasks from a server and destroys it.
int	_Scheduler_CBS_Get_approved_budget (Scheduler_CBS_Server_id server_id, time_t *approved_budget)
	Retrieves the approved budget.
int	_Scheduler_CBS_Get_remaining_budget (Scheduler_CBS_Server_id server_id, time_t *remaining_budget)
	Retrieves remaining budget for the current server instance.
int	_Scheduler_CBS_Get_execution_time (Scheduler_CBS_Server_id server_id, time_t *exec_time, time_t *abs_time)
	Gets relative time info.
int	_Scheduler_CBS_Get_parameters (Scheduler_CBS_Server_id server_id, Scheduler_CBS_Parameters *params)
	Retrieves CBS scheduling parameters.
int	_Scheduler_CBS_Get_server_id (rtems_id task_id, Scheduler_CBS_Server_id *server_id)
	Gets a thread server id.
int	_Scheduler_CBS_Set_parameters (Scheduler_CBS_Server_id server_id, Scheduler_CBS_Parameters *parameters)
	Sets parameters for CBS scheduling.
void	_Scheduler_CBS_Node_initialize (const Scheduler_Control *scheduler, Scheduler_Node *node, Thread_Control *the_thread, Priority_Control priority)
	Initializes a CBS specific scheduler node of the_thread.

Variables
const uint32_t	_Scheduler_CBS_Maximum_servers
Scheduler_CBS_Server	_Scheduler_CBS_Server_list []
const Thread_CPU_budget_operations	_Scheduler_CBS_Budget
	These are the CBS CPU budget operations.

Detailed Description

This group contains the Constant Bandwidth Server (CBS) Scheduler implementation.

Macro Definition Documentation

SCHEDULER_CBS_ENTRY_POINTS

#define SCHEDULER_CBS_ENTRY_POINTS

Value:

{ \
  _Scheduler_EDF_Initialize,         \
  _Scheduler_EDF_Schedule,           \
  _Scheduler_EDF_Yield,              \
  _Scheduler_EDF_Block,              \
  _Scheduler_CBS_Unblock,            \
  _Scheduler_EDF_Update_priority,    \
  _Scheduler_EDF_Map_priority,       \
  _Scheduler_EDF_Unmap_priority,     \
  SCHEDULER_DEFAULT_SMP_OPERATIONS \
  _Scheduler_CBS_Node_initialize,    \
  _Scheduler_default_Node_destroy,   \
  _Scheduler_CBS_Release_job,        \
  _Scheduler_CBS_Cancel_job,         \
  _Scheduler_default_Start_idle      \
  SCHEDULER_DEFAULT_SET_AFFINITY_OPERATION \
}

Entry points for the Constant Bandwidth Server Scheduler.

Note

: The CBS scheduler is an enhancement of EDF scheduler, therefor some routines are similar.

Typedef Documentation

Scheduler_CBS_Budget_overrun

typedef void(*) Scheduler_CBS_Budget_overrun(Scheduler_CBS_Server_id server_id)

Callback function invoked when a budget overrun of a task occurs.

Scheduler_CBS_Server_id

typedef uint32_t Scheduler_CBS_Server_id

Server id.

Function Documentation

_Scheduler_CBS_Attach_thread()

int _Scheduler_CBS_Attach_thread	(	Scheduler_CBS_Server_id	server_id,
		rtems_id	task_id )

Attaches a task to an already existing server.

Attach a task to an already existing server.

Parameters

server_id	The id of the existing server.
task_id	The id of the task to attach.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is so big or there is no thread for this task id.
SCHEDULER_CBS_ERROR_NOSERVER	The server is not yet initialized.
SCHEDULER_CBS_ERROR_FULL	The server already has a task.

_Scheduler_CBS_Cancel_job()

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

Cancels a job.

Parameters

scheduler	The scheduler for the operation.
the_thread	The corresponding thread.
priority_node	The priority node for the operation.
queue_context	The thread queue context.

_Scheduler_CBS_Cleanup()

int _Scheduler_CBS_Cleanup

(

void

)

Cleans up resources associated to the CBS Library.

Cleanup resources associated to the CBS Library.

Returns

This method always returns SCHEDULER_CBS_OK.

_Scheduler_CBS_Create_server()

int _Scheduler_CBS_Create_server	(	Scheduler_CBS_Parameters *	params,
		Scheduler_CBS_Budget_overrun	budget_overrun_callback,
		rtems_id *	server_id )

Creates a new server with specified parameters.

Create a new server with specified parameters.

Parameters

	params	The parameters for the server.
	budget_overrun_callback	The budget overrun for the new server.
[out]	server_id	In the case of success, this parameter contains the id of the newly created server.

Return values

SCHEDULER_CBS_OK	The operation succeeded.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The given parameters are invalid.
SCHEDULER_CBS_ERROR_FULL	The maximum number of servers was already created, a new server cannot be created.

_Scheduler_CBS_Destroy_server()

int _Scheduler_CBS_Destroy_server

(

Scheduler_CBS_Server_id

server_id

)

Detaches all tasks from a server and destroys it.

Detach all tasks from a server and destroy it.

Parameters

server_id

The id of the server to destroy.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is too big.
SCHEDULER_CBS_ERROR_NOSERVER	There is no initialized server with this id.

_Scheduler_CBS_Detach_thread()

int _Scheduler_CBS_Detach_thread	(	Scheduler_CBS_Server_id	server_id,
		rtems_id	task_id )

Detaches from the CBS Server.

Detach from the CBS Server.

Parameters

server_id	The id of the existing server.
task_id	The id of the task to attach.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is to big, or the task with this id is not attached to this server or there is no thread with this task.
SCHEDULER_CBS_ERROR_NOSERVER	The server is not yet initialized.

_Scheduler_CBS_Get_approved_budget()

int _Scheduler_CBS_Get_approved_budget	(	Scheduler_CBS_Server_id	server_id,
		time_t *	approved_budget )

Retrieves the approved budget.

Retrieve the budget that has been approved for the subsequent server instances.

Parameters

	server_id	The id of the server instance of which the budget is wanted.
[out]	approved_budget	Contains the approved budget after a successful method call.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is too big.
SCHEDULER_CBS_ERROR_NOSERVER	There is no initialized server with this id.

_Scheduler_CBS_Get_execution_time()

int _Scheduler_CBS_Get_execution_time	(	Scheduler_CBS_Server_id	server_id,
		time_t *	exec_time,
		time_t *	abs_time )

Gets relative time info.

Retrieve time info relative to server_id. The server status code is returned.

Parameters

	server_id	is the server to get the status code from.
[out]	exec_time	Contains the execution time after a successful method call.
	abs_time	Not apparently used.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is too big.
SCHEDULER_CBS_ERROR_NOSERVER	There is no initialized server with this id.

_Scheduler_CBS_Get_parameters()

int _Scheduler_CBS_Get_parameters	(	Scheduler_CBS_Server_id	server_id,
		Scheduler_CBS_Parameters *	params )

Retrieves CBS scheduling parameters.

Retrieve CBS scheduling parameters.

Parameters

	server_id	The id of the server to get the scheduling parameters from.
[out]	params	Will contain the scheduling parameters after successful method call.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is too big.
SCHEDULER_CBS_ERROR_NOSERVER	There is no initialized server with this id.

_Scheduler_CBS_Get_remaining_budget()

int _Scheduler_CBS_Get_remaining_budget	(	Scheduler_CBS_Server_id	server_id,
		time_t *	remaining_budget )

Retrieves remaining budget for the current server instance.

Retrieve remaining budget for the current server instance.

Parameters

	server_id	The id of the server instance of which the remaining budget is wanted.
[out]	remaining_budget	Contains the remaining budget after a successful method call.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is too big.
SCHEDULER_CBS_ERROR_NOSERVER	There is no initialized server with this id.

_Scheduler_CBS_Get_server_id()

int _Scheduler_CBS_Get_server_id	(	rtems_id	task_id,
		Scheduler_CBS_Server_id *	server_id )

Gets a thread server id.

Get a thread server id, or SCHEDULER_CBS_ERROR_NOT_FOUND if it is not attached to any server.

Parameters

	task_id	The id of the task to get the corresponding server.
[out]	server_id	Will contain the server id after successful method call.

Return values

SCHEDULER_CBS_OK	The operation was successful
SCHEDULER_CBS_ERROR_NOSERVER	There is no server with this task attached.

_Scheduler_CBS_Initialize()

int _Scheduler_CBS_Initialize

(

void

)

_Scheduler_CBS_Initialize

Initializes the CBS library.

Returns

SCHEDULER_CBS_OK This method always returns this status.

_Scheduler_CBS_Node_initialize()

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

Initializes a CBS specific scheduler node of the_thread.

Parameters

	scheduler	The scheduler control for the operation.
[out]	node	The scheduler node to initalize.
	the_thread	The thread to initialize a scheduler node for.
	priority	The priority for the node.

_Scheduler_CBS_Release_job()

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

Releases a job.

Parameters

scheduler	The scheduler for the operation.
the_thread	The corresponding thread.
priority_node	The priority node for the operation.
deadline	The deadline for the job.
queue_context	The thread queue context.

_Scheduler_CBS_Set_parameters()

int _Scheduler_CBS_Set_parameters	(	Scheduler_CBS_Server_id	server_id,
		Scheduler_CBS_Parameters *	parameters )

Sets parameters for CBS scheduling.

Change CBS scheduling parameters.

Parameters

server_id	The id of the server.
parameters	The parameters to set.

Return values

SCHEDULER_CBS_OK	The operation was successful.
SCHEDULER_CBS_ERROR_INVALID_PARAMETER	The server id is too big or the given parameters are invalid.
SCHEDULER_CBS_ERROR_NOSERVER	There is no server with this id.

_Scheduler_CBS_Unblock()

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

Unblocks a thread.

Parameters

scheduler	The scheduler control.
the_thread	The thread to unblock.
node	The scheduler node.

Variable Documentation

_Scheduler_CBS_Maximum_servers

const uint32_t _Scheduler_CBS_Maximum_servers

extern

Maximum number of simultaneous servers.

_Scheduler_CBS_Server_list

Scheduler_CBS_Server _Scheduler_CBS_Server_list[]

extern

List of servers. The Scheduler_CBS_Server is the index to the array of pointers to _Scheduler_CBS_Server_list.