Constant Bandwidth Server (CBS) Scheduler

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

Files
file	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	schedulercbsimpl.h
	This header file provides interfaces of the Constant Bandwidth Server (CBS) Scheduler which are only used by the implementation.
file	schedulercbs.c
	This source file contains the implementation of _Scheduler_CBS_Budget_callout() and _Scheduler_CBS_Initialize().
file	schedulercbsattachthread.c
	This source file contains the implementation of _Scheduler_CBS_Attach_thread().
file	schedulercbscleanup.c
	This source file contains the implementation of _Scheduler_CBS_Cleanup().
file	schedulercbscreateserver.c
	This source file contains the implementation of _Scheduler_CBS_Create_server().
file	schedulercbsdestroyserver.c
	This source file contains the implementation of _Scheduler_CBS_Destroy_server().
file	schedulercbsdetachthread.c
	This source file contains the implementation of _Scheduler_CBS_Detach_thread().
file	schedulercbsgetapprovedbudget.c
	This source file contains the implementation of _Scheduler_CBS_Get_approved_budget().
file	schedulercbsgetexecutiontime.c
	This source file contains the implementation of _Scheduler_CBS_Get_execution_time().
file	schedulercbsgetparameters.c
	This source file contains the implementation of _Scheduler_CBS_Get_parameters().
file	schedulercbsgetremainingbudget.c
	This source file contains the implementation of _Scheduler_CBS_Get_remaining_budget().
file	schedulercbsgetserverid.c
	This source file contains the implementation of _Scheduler_CBS_Get_server_id().
file	schedulercbsnodeinit.c
	This source file contains the implementation of _Scheduler_CBS_Node_initialize().
file	schedulercbsreleasejob.c
	This source file contains the implementation of _Scheduler_CBS_Release_job().
file	schedulercbssetparameters.c
	This source file contains the implementation of _Scheduler_CBS_Set_parameters().
file	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,       /* initialize entry point */ \
    _Scheduler_EDF_Schedule,         /* schedule entry point */ \
    _Scheduler_EDF_Yield,            /* yield entry point */ \
    _Scheduler_EDF_Block,            /* block entry point */ \
    _Scheduler_CBS_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_DEFAULT_SMP_OPERATIONS \
    _Scheduler_CBS_Node_initialize,  /* node initialize entry point */ \
    _Scheduler_default_Node_destroy, /* node destroy entry point */ \
    _Scheduler_CBS_Release_job,      /* new period of task */ \
    _Scheduler_CBS_Cancel_job,       /* cancel period of task */ \
    _Scheduler_default_Start_idle    /* start idle entry point */ \
    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.