This handler encapsulates functionality related to managing sets of threads that are ready for execution. More...

Collaboration diagram for Scheduler Handler:

Modules
	CBS Scheduler

	EDF Scheduler

	Deterministic Priority Scheduler

	Simple Priority Scheduler

	SMP Scheduler
	The scheduler nodes can be in four states.

Files
file	scheduler.c
	Scheduler Initialize.

file	schedulercbs.c
	CBS Scheduler Budget Handler.

file	schedulercbsattachthread.c
	Attach Scheduler CBS Thread.

file	schedulercbscleanup.c
	Scheduler CBS Cleanup.

file	schedulercbscreateserver.c
	Scheduler CBS Create Server.

file	schedulercbsdestroyserver.c
	Scheduler CBS Destroy Server.

file	schedulercbsdetachthread.c
	Detach from the CBS Server.

file	schedulercbsgetapprovedbudget.c
	Scheduler CBS Get Approved Budget.

file	schedulercbsgetexecutiontime.c
	Get Thread Execution Info.

file	schedulercbsgetparameters.c
	_Scheduler_CBS_Get_parameters

file	schedulercbsgetremainingbudget.c
	Scheduler CBS Get Remaining Budget.

file	schedulercbsgetserverid.c
	Scheduler CBS Get Server id.

file	schedulercbsreleasejob.c
	Scheduler CBS Release Job.

file	schedulercbssetparameters.c
	Set Parameters for CBS Scheduling.

file	schedulercbsunblock.c
	Unblocks a Thread from the Queue.

file	schedulerdefaultgetaffinity.c
	Scheduler Default Get Affinity Operation.

file	schedulerdefaultnodedestroy.c
	Scheduler Default Node Destruction Operation.

file	schedulerdefaultnodeinit.c
	Scheduler Default Node Initialization Operation.

file	schedulerdefaultreleasejob.c
	Default Scheduler Release Job Operation.

file	schedulerdefaultsetaffinity.c
	Scheduler Default Set Affinity Operation.

file	schedulerdefaulttick.c
	Default Scheduler At Tick Handler.

file	schedulerdefaultupdate.c
	Scheduler Default Update Operation.

file	scheduleredf.c
	Scheduler EDF Initialize and Support.

file	scheduleredfblock.c
	Removes the Thread from Ready Queue.

file	scheduleredfchangepriority.c
	Scheduler EDF Extract.

file	scheduleredfnodeinit.c
	Scheduler EDF Allocate.

file	scheduleredfprioritycompare.c
	Compares Priorities of Threads.

file	scheduleredfreleasejob.c
	Scheduler EDF Release Job.

file	scheduleredfschedule.c
	Scheduler EDF Allocate.

file	scheduleredfunblock.c
	Scheduler EDF Unblock.

file	scheduleredfupdate.c
	Scheduler EDF Update.

file	scheduleredfyield.c
	Scheduler EDF Yield.

file	schedulerpriorityblock.c
	Scheduler Priority Block.

file	schedulerprioritychangepriority.c
	Removes Thread from Thread Queue.

file	schedulerpriorityprioritycompare.c
	Scheduler Priority Compare Two Priorities.

file	schedulerpriorityschedule.c
	Priority Scheduler Schedule Method.

file	schedulerpriorityunblock.c
	Scheduler Priority Unblock.

file	schedulerpriorityupdate.c
	Update Scheduler Priority.

file	schedulerpriorityyield.c
	Scheduler Priority Yield.

file	schedulersimple.c
	Scheduler Simple Functions.

file	schedulersimpleblock.c
	Simple Scheduler Block a Thread.

file	schedulersimplechangepriority.c
	Removes a Thread from the Simple Queue.

file	schedulersimpleschedule.c
	Simple Schedule Determine Heir.

file	schedulersimpleunblock.c
	Scheduler Simple Handler / Unblock.

file	schedulersimpleyield.c
	Simple Schedule Yield CPU.

file	schedulersmpdebug.c
	Scheduler SMP Debug Implementation.

Data Structures
struct	Scheduler_Operations
	The scheduler operations. More...

struct	Scheduler_Context
	Scheduler context. More...

struct	Scheduler_Control
	Scheduler control. More...

struct	Scheduler_Node
	Scheduler node for per-thread data. More...

Macros
#define	SCHEDULER_RETURN_VOID_OR_NULL return

#define	_Scheduler_Count ( (size_t) 1 )
	Count of registered schedulers. More...

#define	SCHEDULER_OPERATION_DEFAULT_ASK_FOR_HELP

#define	SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY

Typedefs
typedef struct Scheduler_Control	Scheduler_Control

typedef struct Scheduler_Node	Scheduler_Node

typedef void	Scheduler_Void_or_thread

typedef struct Scheduler_Context	Scheduler_Context
	Scheduler context. More...

Functions
void	_Scheduler_default_Schedule (const Scheduler_Control scheduler, Thread_Control the_thread)
	Does nothing. More...

void	_Scheduler_default_Node_initialize (const Scheduler_Control scheduler, Thread_Control the_thread)
	Does nothing. More...

void	_Scheduler_default_Node_destroy (const Scheduler_Control scheduler, Thread_Control the_thread)
	Does nothing. More...

void	_Scheduler_default_Update_priority (const Scheduler_Control scheduler, Thread_Control the_thread, Priority_Control new_priority)
	Does nothing. More...

void	_Scheduler_default_Release_job (const Scheduler_Control scheduler, Thread_Control the_thread, uint32_t deadline)
	Does nothing. More...

void	_Scheduler_default_Tick (const Scheduler_Control scheduler, Thread_Control executing)
	Performs tick operations depending on the CPU budget algorithm for each executing thread. More...

void	_Scheduler_default_Start_idle (const Scheduler_Control scheduler, Thread_Control the_thread, struct Per_CPU_Control *cpu)
	Starts an idle thread. More...

void	_Scheduler_Handler_initialization (void)
	Initializes the scheduler to the policy chosen by the user. More...

RTEMS_INLINE_ROUTINE Scheduler_Context *	_Scheduler_Get_context (const Scheduler_Control *scheduler)

RTEMS_INLINE_ROUTINE const Scheduler_Control *	_Scheduler_Get (const Thread_Control *the_thread)

RTEMS_INLINE_ROUTINE const Scheduler_Control *	_Scheduler_Get_own (const Thread_Control *the_thread)

RTEMS_INLINE_ROUTINE const Scheduler_Control *	_Scheduler_Get_by_CPU_index (uint32_t cpu_index)

RTEMS_INLINE_ROUTINE const Scheduler_Control *	_Scheduler_Get_by_CPU (const Per_CPU_Control *cpu)

RTEMS_INLINE_ROUTINE Scheduler_Node *	_Scheduler_Thread_get_own_node (const Thread_Control *the_thread)

RTEMS_INLINE_ROUTINE void	_Scheduler_Schedule (Thread_Control *the_thread)
	The preferred method to add a new scheduler is to define the jump table entries and add a case to the _Scheduler_Initialize routine. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Yield (Thread_Control *the_thread)
	Scheduler yield with a particular thread. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Block (Thread_Control *the_thread)
	Blocks a thread with respect to the scheduler. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Unblock (Thread_Control *the_thread)
	Unblocks a thread with respect to the scheduler. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Change_priority (Thread_Control *the_thread, Priority_Control new_priority, bool prepend_it)
	Propagates a priority change of a thread to the scheduler. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Node_initialize (const Scheduler_Control scheduler, Thread_Control the_thread)
	Initializes a scheduler node. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Node_destroy (const Scheduler_Control scheduler, Thread_Control the_thread)
	Destroys a scheduler node. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Update_priority (Thread_Control *the_thread, Priority_Control new_priority)
	Updates the scheduler about a priority change of a not ready thread. More...

RTEMS_INLINE_ROUTINE int	_Scheduler_Priority_compare (const Scheduler_Control *scheduler, Priority_Control p1, Priority_Control p2)
	Compares two priority values. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Release_job (Thread_Control *the_thread, uint32_t length)
	Releases a job of a thread with respect to the scheduler. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Tick (void)
	Scheduler method invoked at each clock tick. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Start_idle (const Scheduler_Control scheduler, Thread_Control the_thread, Per_CPU_Control *cpu)
	Starts the idle thread for a particular processor. More...

RTEMS_INLINE_ROUTINE bool	_Scheduler_Has_processor_ownership (const Scheduler_Control *scheduler, uint32_t cpu_index)

RTEMS_INLINE_ROUTINE void	_Scheduler_Set (const Scheduler_Control scheduler, Thread_Control the_thread)

RTEMS_INLINE_ROUTINE void	_Scheduler_Update_heir (Thread_Control *new_heir, bool force_dispatch)

RTEMS_INLINE_ROUTINE void	_Scheduler_Generic_block (const Scheduler_Control scheduler, Thread_Control the_thread, void(extract)(const Scheduler_Control , Thread_Control ), void(schedule)(const Scheduler_Control , Thread_Control , bool))

RTEMS_INLINE_ROUTINE bool	_Scheduler_Is_priority_lower_than (const Scheduler_Control *scheduler, Priority_Control p1, Priority_Control p2)
	Returns true if p1 encodes a lower priority than p2 in the intuitive sense of priority.

RTEMS_INLINE_ROUTINE bool	_Scheduler_Is_priority_higher_than (const Scheduler_Control *scheduler, Priority_Control p1, Priority_Control p2)
	Returns true if p1 encodes a higher priority than p2 in the intuitive sense of priority.

RTEMS_INLINE_ROUTINE uint32_t	_Scheduler_Get_processor_count (const Scheduler_Control *scheduler)

RTEMS_INLINE_ROUTINE Objects_Id	_Scheduler_Build_id (uint32_t scheduler_index)

RTEMS_INLINE_ROUTINE uint32_t	_Scheduler_Get_index_by_id (Objects_Id id)

RTEMS_INLINE_ROUTINE bool	_Scheduler_Get_by_id (Objects_Id id, const Scheduler_Control **scheduler_p)

RTEMS_INLINE_ROUTINE bool	_Scheduler_Is_id_valid (Objects_Id id)

RTEMS_INLINE_ROUTINE uint32_t	_Scheduler_Get_index (const Scheduler_Control *scheduler)

RTEMS_INLINE_ROUTINE Scheduler_Node *	_Scheduler_Thread_get_node (const Thread_Control *the_thread)

RTEMS_INLINE_ROUTINE void	_Scheduler_Node_do_initialize (Scheduler_Node node, Thread_Control the_thread)

RTEMS_INLINE_ROUTINE void	_Scheduler_Acquire (Thread_Control the_thread, ISR_lock_Context lock_context)
	Acquires the scheduler instance of the thread. More...

RTEMS_INLINE_ROUTINE void	_Scheduler_Release (Thread_Control the_thread, ISR_lock_Context lock_context)
	Releases the scheduler instance of the thread. More...

Variables
const Scheduler_Control	_Scheduler_Table []
	Registered schedulers. More...

Detailed Description

This handler encapsulates functionality related to managing sets of threads that are ready for execution.

Macro Definition Documentation

◆ _Scheduler_Count

#define _Scheduler_Count ( (size_t) 1 )

Count of registered schedulers.

Application provided via <rtems/confdefs.h> on SMP configurations.

It is very important that this is a compile-time constant on uni-processor configurations (in this case RTEMS_SMP is not defined) so that the compiler can optimize the some loops away

See also: _Scheduler_Table.

Referenced by _Scheduler_Handler_initialization(), and rtems_scheduler_ident().

Typedef Documentation

◆ Scheduler_Context

typedef struct Scheduler_Context Scheduler_Context

Scheduler context.

The scheduler context of a particular scheduler implementation must place this structure at the begin of its context structure.

Function Documentation

◆ _Scheduler_Acquire()

RTEMS_INLINE_ROUTINE void _Scheduler_Acquire	(	Thread_Control *	the_thread,
		ISR_lock_Context *	lock_context
	)

Acquires the scheduler instance of the thread.

Parameters

[in]	the_thread	The thread.
[in]	lock_context	The lock context for _Scheduler_Release().

References _ISR_lock_ISR_disable_and_acquire.

◆ _Scheduler_Block()

RTEMS_INLINE_ROUTINE void _Scheduler_Block ( Thread_Control * the_thread )

Blocks a thread with respect to the scheduler.

This routine removes the_thread from the scheduling decision for the scheduler. The primary task is to remove the thread from the ready queue. It performs any necessary schedulering operations including the selection of a new heir thread.

Parameters

[in] the_thread The thread.

◆ _Scheduler_Change_priority()

RTEMS_INLINE_ROUTINE void _Scheduler_Change_priority	(	Thread_Control *	the_thread,
		Priority_Control	new_priority,
		bool	prepend_it
	)

Propagates a priority change of a thread to the scheduler.

The caller must ensure that the thread is in the ready state. The caller must ensure that the priority value actually changed and is not equal to the current priority value.

The operation must update the heir and thread dispatch necessary variables in case the set of scheduled threads changes.

Parameters

[in]	the_thread	The thread changing its priority.
[in]	new_priority	The new thread priority.
[in]	prepend_it	In case this is true, then enqueue the thread as the first of its priority group, otherwise enqueue the thread as the last of its priority group.

◆ _Scheduler_default_Node_destroy()

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

Does nothing.

Parameters

[in]	scheduler	Unused.
[in]	the_thread	Unused.

◆ _Scheduler_default_Node_initialize()

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

Does nothing.

Parameters

[in]	scheduler	Unused.
[in]	the_thread	Unused.

◆ _Scheduler_default_Release_job()

void _Scheduler_default_Release_job	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		uint32_t	deadline
	)

Does nothing.

Parameters

[in]	scheduler	Unused.
[in]	the_thread	Unused.
[in]	deadline	Unused.

◆ _Scheduler_default_Schedule()

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

Does nothing.

Parameters

[in]	scheduler	Unused.
[in]	the_thread	Unused.

◆ _Scheduler_default_Start_idle()

void _Scheduler_default_Start_idle	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		struct Per_CPU_Control *	cpu
	)

Starts an idle thread.

Parameters

[in]	scheduler	The scheduler.
[in]	the_thread	An idle thread.
[in]	cpu	This parameter is unused.

References _Scheduler_Unblock().

◆ _Scheduler_default_Tick()

void _Scheduler_default_Tick	(	const Scheduler_Control *	scheduler,
		Thread_Control *	executing
	)

Performs tick operations depending on the CPU budget algorithm for each executing thread.

This routine is invoked as part of processing each clock tick.

Parameters

[in]	scheduler	The scheduler.
[in]	executing	An executing thread.

References _States_Is_ready(), Thread_Control::budget_algorithm, Thread_Control::current_state, and Thread_Control::is_preemptible.

◆ _Scheduler_default_Update_priority()

void _Scheduler_default_Update_priority	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Priority_Control	new_priority
	)

Does nothing.

Parameters

[in]	scheduler	Unused.
[in]	the_thread	Unused.
[in]	new_priority	Unused.

◆ _Scheduler_Handler_initialization()

void _Scheduler_Handler_initialization ( void )

Initializes the scheduler to the policy chosen by the user.

This routine initializes the scheduler to the policy chosen by the user through confdefs, or to the priority scheduler with ready chains by default.

References _Scheduler_Count, _Scheduler_Table, Scheduler_Operations::initialize, and Scheduler_Control::Operations.

◆ _Scheduler_Node_destroy()

RTEMS_INLINE_ROUTINE void _Scheduler_Node_destroy	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread
	)

Destroys a scheduler node.

The caller must ensure that _Scheduler_Node_destroy() will be called only after a corresponding _Scheduler_Node_initialize().

Parameters

[in]	scheduler	The scheduler instance.
[in]	the_thread	The thread containing the scheduler node.

References Scheduler_Operations::node_destroy, and Scheduler_Control::Operations.

◆ _Scheduler_Node_initialize()

RTEMS_INLINE_ROUTINE void _Scheduler_Node_initialize	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread
	)

Initializes a scheduler node.

The scheduler node contains arbitrary data on function entry. The caller must ensure that _Scheduler_Node_destroy() will be called after a _Scheduler_Node_initialize() before the memory of the scheduler node is destroyed.

Parameters

[in]	scheduler	The scheduler instance.
[in]	the_thread	The thread containing the scheduler node.

References Scheduler_Operations::node_initialize, and Scheduler_Control::Operations.

◆ _Scheduler_Priority_compare()

RTEMS_INLINE_ROUTINE int _Scheduler_Priority_compare	(	const Scheduler_Control *	scheduler,
		Priority_Control	p1,
		Priority_Control	p2
	)

Compares two priority values.

Parameters

[in]	scheduler	The scheduler instance.
[in]	p1	The first priority value.
[in]	p2	The second priority value.

Return values

negative	The value p1 encodes a lower priority than p2 in the intuitive sense of priority.
0	The priorities p1 and p2 are equal.
positive	The value p1 encodes a higher priority than p2 in the intuitive sense of priority.

See also: _Scheduler_Is_priority_lower_than() and _Scheduler_Is_priority_higher_than().

References Scheduler_Control::Operations, and Scheduler_Operations::priority_compare.

Referenced by _Scheduler_Is_priority_higher_than(), and _Scheduler_Is_priority_lower_than().

◆ _Scheduler_Release()

RTEMS_INLINE_ROUTINE void _Scheduler_Release	(	Thread_Control *	the_thread,
		ISR_lock_Context *	lock_context
	)

Releases the scheduler instance of the thread.

Parameters

[in]	the_thread	The thread.
[in]	lock_context	The lock context used for _Scheduler_Acquire().

References _ISR_lock_Release_and_ISR_enable.

◆ _Scheduler_Release_job()

RTEMS_INLINE_ROUTINE void _Scheduler_Release_job	(	Thread_Control *	the_thread,
		uint32_t	length
	)

Releases a job of a thread with respect to the scheduler.

Parameters

[in]	the_thread	The thread.
[in]	length	The period length.

◆ _Scheduler_Schedule()

RTEMS_INLINE_ROUTINE void _Scheduler_Schedule ( Thread_Control * the_thread )

The preferred method to add a new scheduler is to define the jump table entries and add a case to the _Scheduler_Initialize routine.

Generic scheduling implementations that rely on the ready queue only can be found in the _Scheduler_queue_XXX functions. General scheduling decision.

This kernel routine implements the scheduling decision logic for the scheduler. It does NOT dispatch.

Parameters

[in] the_thread The thread which state changed previously.

◆ _Scheduler_Start_idle()

RTEMS_INLINE_ROUTINE void _Scheduler_Start_idle	(	const Scheduler_Control *	scheduler,
		Thread_Control *	the_thread,
		Per_CPU_Control *	cpu
	)

Starts the idle thread for a particular processor.

Parameters

[in]	scheduler	The scheduler instance.
[in,out]	the_thread	The idle thread for the processor.
[in,out]	cpu	The processor for the idle thread.

See also: _Thread_Create_idle().

References Scheduler_Control::Operations, RTEMS_INLINE_ROUTINE, and Scheduler_Operations::start_idle.

◆ _Scheduler_Tick()

RTEMS_INLINE_ROUTINE void _Scheduler_Tick ( void )

Scheduler method invoked at each clock tick.

This method is invoked at each clock tick to allow the scheduler implementation to perform any activities required. For the scheduler which support standard RTEMS features, this includes time-slicing management.

Referenced by _Watchdog_Tick().

◆ _Scheduler_Unblock()

RTEMS_INLINE_ROUTINE void _Scheduler_Unblock ( Thread_Control * the_thread )

Unblocks a thread with respect to the scheduler.

This routine adds the_thread to the scheduling decision for the scheduler. The primary task is to add the thread to the ready queue per the schedulering policy and update any appropriate scheduling variables, for example the heir thread.

Parameters

[in] the_thread The thread.

Referenced by _Scheduler_default_Start_idle().

◆ _Scheduler_Update_priority()

RTEMS_INLINE_ROUTINE void _Scheduler_Update_priority	(	Thread_Control *	the_thread,
		Priority_Control	new_priority
	)

Updates the scheduler about a priority change of a not ready thread.

Parameters

[in]	the_thread	The thread.
[in]	new_priority	The new priority of the thread.

◆ _Scheduler_Yield()

RTEMS_INLINE_ROUTINE void _Scheduler_Yield ( Thread_Control * the_thread )

Scheduler yield with a particular thread.

This routine is invoked when a thread wishes to voluntarily transfer control of the processor to another thread.

Parameters

[in] the_thread The yielding thread.

Variable Documentation

◆ _Scheduler_Table

const Scheduler_Control _Scheduler_Table[]

Registered schedulers.

Application provided via <rtems/confdefs.h>.

See also: _Scheduler_Count.

Referenced by _Scheduler_Handler_initialization(), and rtems_scheduler_ident().

Modules

Files

Data Structures

Macros

Typedefs

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ _Scheduler_Count

Typedef Documentation

◆ Scheduler_Context

Function Documentation

◆ _Scheduler_Acquire()

◆ _Scheduler_Block()

◆ _Scheduler_Change_priority()

◆ _Scheduler_default_Node_destroy()

◆ _Scheduler_default_Node_initialize()

◆ _Scheduler_default_Release_job()

◆ _Scheduler_default_Schedule()

◆ _Scheduler_default_Start_idle()

◆ _Scheduler_default_Tick()

◆ _Scheduler_default_Update_priority()

◆ _Scheduler_Handler_initialization()

◆ _Scheduler_Node_destroy()

◆ _Scheduler_Node_initialize()

◆ _Scheduler_Priority_compare()

◆ _Scheduler_Release()

◆ _Scheduler_Release_job()

◆ _Scheduler_Schedule()

◆ _Scheduler_Start_idle()

◆ _Scheduler_Tick()

◆ _Scheduler_Unblock()

◆ _Scheduler_Update_priority()

◆ _Scheduler_Yield()

Variable Documentation

◆ _Scheduler_Table