Interface for the implementation of the kernel of the scheduler. It supports Soft and Hard Real-Time modes. More...

#include <stk_common.h>

Inheritance diagram for stk::IKernel:

Public Types
enum	EKernelState : uint8_t { KSTATE_INACTIVE = 0 , KSTATE_READY , KSTATE_RUNNING , KSTATE_SUSPENDED }
	Kernel state. More...

Public Member Functions
virtual void	Initialize (uint32_t resolution_us=PERIODICITY_DEFAULT)=0
	Initialize kernel.
virtual void	AddTask (ITask *user_task)=0
	Add user task.
virtual void	AddTask (ITask *user_task, Timeout periodicity_tc, Timeout deadline_tc, Timeout start_delay_tc)=0
	Add user task.
virtual void	RemoveTask (ITask *user_task)=0
	Remove a previously added task from the kernel when it is not started.
virtual void	ScheduleTaskRemoval (ITask *user_task)=0
	Schedule task removal from scheduling (exit).
virtual void	SuspendTask (ITask *user_task, bool &suspended)=0
	Suspend task.
virtual void	ResumeTask (ITask *user_task)=0
	Resume task.
virtual size_t	EnumerateKernelTasks (ArrayView< IKernelTask * > tasks)=0
	Enumerate kernel tasks.
virtual size_t	EnumerateTasks (ArrayView< ITask * > user_tasks)=0
	Enumerate user tasks.
template<size_t TMaxCount, typename TCallback>
size_t	EnumerateTasksT (TCallback &&callback)
	Enumerate tasks, invoking a callback for each active task.
virtual void	Start ()=0
	Start kernel scheduling.
virtual EKernelState	GetState () const =0
	Get a snapshot of the kernel state.
virtual IPlatform *	GetPlatform ()=0
	Get platform driver instance.
virtual ITaskSwitchStrategy *	GetSwitchStrategy ()=0
	Get switch strategy instance.

Protected Member Functions
	~IKernel ()=default
	Destructor.

Detailed Description

Interface for the implementation of the kernel of the scheduler. It supports Soft and Hard Real-Time modes.

Note: Mediator design pattern.

Definition at line 1349 of file stk_common.h.

Member Enumeration Documentation

◆ EKernelState

enum stk::IKernel::EKernelState : uint8_t

Kernel state.

Enumerator
KSTATE_INACTIVE	Not ready, IKernel::Initialize() must be called.
KSTATE_READY	Ready to start, IKernel::Start() must be called.
KSTATE_RUNNING	Initialized and running, IKernel::Start() was called successfully.
KSTATE_SUSPENDED	Scheduling is suspended with IKernelService::Suspend().

Definition at line 1355 of file stk_common.h.

    {
        KSTATE_INACTIVE = 0, 
        KSTATE_READY,        
        KSTATE_RUNNING,      
        KSTATE_SUSPENDED     
    };

Constructor & Destructor Documentation

◆ ~IKernel()

stk::IKernel::~IKernel ( )

protecteddefault

Destructor.

Member Function Documentation

◆ AddTask() [1/2]

virtual void stk::IKernel::AddTask ( ITask * user_task )

pure virtual

Add user task.

Note: This function is for Soft Real-Time modes only (i.e. KERNEL_HRT must not be set in the kernel mode flags).

Parameters

[in] user_task Pointer to the user task to add.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

Referenced by stk::time::TimerHost::Initialize(), stk_kernel_add_task(), and stk_kernel_add_task_hrt().

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◆ AddTask() [2/2]

virtual void stk::IKernel::AddTask	(	ITask *	user_task,
		Timeout	periodicity_tc,
		Timeout	deadline_tc,
		Timeout	start_delay_tc )

pure virtual

Add user task.

Note: This function is for Hard Real-time mode only, e.g. stk::KERNEL_HRT is used as parameter.

Parameters

[in]	user_task	Pointer to the user task to add.
[in]	periodicity_tc	Periodicity time at which task is scheduled (ticks).
[in]	deadline_tc	Deadline time within which a task must complete its work (ticks).
[in]	start_delay_tc	Initial start delay for the task (ticks).

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

◆ EnumerateKernelTasks()

virtual size_t stk::IKernel::EnumerateKernelTasks ( ArrayView< IKernelTask * > tasks )

pure virtual

Enumerate kernel tasks.

Parameters

[in] tasks Reference to the ArrayView of IKernelTask pointers.

Returns: Number of tasks in the array.

Warning: ISR-safe.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

◆ EnumerateTasks()

virtual size_t stk::IKernel::EnumerateTasks ( ArrayView< ITask * > user_tasks )

pure virtual

Enumerate user tasks.

Parameters

[in] user_tasks Reference to the ArrayView of ITask pointers.

Returns: Number of tasks in the array.

Warning: ISR-safe.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

Referenced by EnumerateTasksT(), and stk_kernel_enumerate_tasks().

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◆ EnumerateTasksT()

template<size_t TMaxCount, typename TCallback>

size_t stk::IKernel::EnumerateTasksT ( TCallback && callback )

inline

Enumerate tasks, invoking a callback for each active task.

Template Parameters

TMaxCount	Maximum number of tasks to enumerate. Should match or exceed the kernel's task capacity. Determines the size of the internal stack-allocated buffer (TMaxCount * sizeof(ITask*) bytes on the stack).
TCallback	Callable type, deduced automatically. Must satisfy: bool(ITask*)

Parameters

[in] callback Callable invoked for each active task. Return true to continue, false to stop early.

Returns: Number of tasks visited (up to TMaxCount).

Warning: ISR-safe.

Example:

kernel.EnumerateTasks<_STK_KERNEL_TASKS_COUNT>([](ITask *t) {
    Log(t->GetTraceName());
    return true; // continue
});

Definition at line 1460 of file stk_common.h.

    {
        STK_STATIC_ASSERT(TMaxCount > 0U);
 
        ITask *tasks[TMaxCount] = {};        
        size_t count = EnumerateTasks(ArrayView<ITask *>(tasks, TMaxCount));
        size_t i = 0U;
        bool fetch_next = true;
 
        while ((i < count) && fetch_next)
        {
            fetch_next = callback(tasks[i]);
            ++i;
        }
 
        return i;
    }

References EnumerateTasks(), and STK_STATIC_ASSERT.

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◆ GetPlatform()

virtual IPlatform * stk::IKernel::GetPlatform ( )

pure virtual

Get platform driver instance.

Returns: Pointer to the IPlatform concrete class instance.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

Referenced by SetEventOverrider(), stk_kernel_process_hard_fault(), stk_kernel_process_tick(), stk_kernel_resume(), and stk_kernel_suspend().

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◆ GetState()

virtual EKernelState stk::IKernel::GetState ( ) const

pure virtual

Get a snapshot of the kernel state.

Returns: Kernel state.

See also: EKernelState

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

Referenced by stk_kernel_get_state(), and stk_kernel_is_started().

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◆ GetSwitchStrategy()

virtual ITaskSwitchStrategy * stk::IKernel::GetSwitchStrategy ( )

pure virtual

Get switch strategy instance.

Returns: Pointer to the ITaskSwitchStrategy concrete class instance.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

◆ Initialize()

virtual void stk::IKernel::Initialize ( uint32_t resolution_us = PERIODICITY_DEFAULT )

pure virtual

Initialize kernel.

Parameters

[in] resolution_us Resolution of the system tick (SysTick) timer in microseconds. Defaults to PERIODICITY_DEFAULT (1000 µs = 1 ms).

Note: Must be called before AddTask() and Start().; If running on an STM32 device with HAL driver or on QEMU, do not change the default resolution (PERIODICITY_DEFAULT). STM32's HAL expects 1 millisecond resolution and QEMU does not have enough resolution on Windows to operate correctly at sub-millisecond resolution.; Kernel must be in KSTATE_INACTIVE state.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

References stk::PERIODICITY_DEFAULT.

Referenced by stk_kernel_init().

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◆ RemoveTask()

virtual void stk::IKernel::RemoveTask ( ITask * user_task )

pure virtual

Remove a previously added task from the kernel when it is not started.

Parameters

[in] user_task User task to remove. Must not be nullptr.

Note: Only valid before Start() (i.e. while the kernel is not running). To remove tasks after Start() the task should return from its Run function (in KERNEL_DYNAMIC mode the slot is freed automatically on the next tick).

Warning: Must only be called when kernel is not running, otherwise call ScheduleTaskRemoval.; KERNEL_DYNAMIC mode only. Asserts if called in KERNEL_STATIC or KERNEL_HRT mode, or if called after Start().

See also: ScheduleTaskRemoval

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

Referenced by stk_kernel_remove_task().

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◆ ResumeTask()

virtual void stk::IKernel::ResumeTask ( ITask * user_task )

pure virtual

Resume task.

Parameters

[in] user_task Pointer to the user task to resume.

Implemented in stk::Kernel< TMode, TSize, TStrategy, TPlatform >, stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >, and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC|stk::KERNEL_TICKLESS,(16U), stk::SwitchStrategyFP32, stk::PlatformDefault >.

Referenced by stk_kernel_resume_task().

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◆ ScheduleTaskRemoval()

virtual void stk::IKernel::ScheduleTaskRemoval ( ITask * user_task )

pure virtual

Schedule task removal from scheduling (exit).

Parameters

[in] user_task User task to remove. Must not be nullptr.

Warning: KERNEL_DYNAMIC mode only. Asserts if called in KERNEL_STATIC or KERNEL_HRT mode, or if called before Start() (i.e. while the kernel is not yet running). Use RemoveTask instead to remove a task while the kernel is not running.