stk::ITask Class Reference

Interface for a user task. More...

#include <stk_common.h>

Inheritance diagram for stk::ITask:

Collaboration diagram for stk::ITask:

Public Member Functions
virtual void	Run ()=0
	Entry point of the user task.
virtual EAccessMode	GetAccessMode () const =0
	Get hardware access mode of the user task.
virtual void	OnDeadlineMissed (uint32_t duration)=0
	Called by the scheduler if deadline of the task is missed when Kernel is operating in Hard Real-Time mode (see stk::KERNEL_HRT).
virtual void	OnExit ()=0
	Called by the kernel before removal from the scheduling (see stk::KERNEL_DYNAMIC).
virtual int32_t	GetWeight () const =0
	Get static base weight of the task.
virtual TId	GetId () const =0
	Get task Id set by application.
virtual const char *	GetTraceName () const =0
	Get task trace name set by application.
virtual Word *	GetStack () const =0
	Get pointer to the stack memory.
virtual size_t	GetStackSize () const =0
	Get number of elements of the stack memory array.
virtual size_t	GetStackSizeBytes () const =0
	Get size of the memory in bytes.
virtual size_t	GetStackSpace ()
	Get available stack space.

Detailed Description

Interface for a user task.

Note

Inherit this interface by your thread/task class to make it schedulable by the Kernel.

Usage example:

class MyTask : public stk::Task<256, ACCESS_USER>
{
    void Run() override
    {
        while (true)
        {
            // task logic here
        }
    }
};
 
MyTask task1, task2;
kernel.AddTask(&task1);
kernel.AddTask(&task2);

Definition at line 490 of file stk_common.h.

Member Function Documentation

GetAccessMode()

virtual EAccessMode stk::ITask::GetAccessMode ( ) const

pure virtual

Get hardware access mode of the user task.

Implemented in stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

Referenced by stk::Kernel< TMode, TSize, TStrategy, TPlatform >::KernelTask::Bind().

Here is the caller graph for this function:

GetId()

virtual TId stk::ITask::GetId ( ) const

pure virtual

Get task Id set by application.

Returns

Application-defined task identifier. Return 0 if unused.

Note

Used for debugging and tracing only. The kernel does not interpret this value.

Implemented in stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

Referenced by stk::Kernel< TMode, TSize, TStrategy, TPlatform >::KernelTask::Bind().

Here is the caller graph for this function:

GetStack()

virtual Word * stk::IStackMemory::GetStack ( ) const

pure virtualinherited

Get pointer to the stack memory.

Implemented in stk::StackMemoryWrapper< _StackSize >, stk::StackMemoryWrapper< STACK_SIZE_MIN >, stk::StackMemoryWrapper<(32U)>, stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

Referenced by stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >::AllocateNewTask(), GetStackSpace(), stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >::StateSwitch(), and stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >::StateWake().

Here is the caller graph for this function:

GetStackSize()

virtual size_t stk::IStackMemory::GetStackSize ( ) const

pure virtualinherited

Get number of elements of the stack memory array.

Implemented in stk::StackMemoryWrapper< _StackSize >, stk::StackMemoryWrapper< STACK_SIZE_MIN >, stk::StackMemoryWrapper<(32U)>, stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

Referenced by GetStackSpace().

Here is the caller graph for this function:

GetStackSizeBytes()

virtual size_t stk::IStackMemory::GetStackSizeBytes ( ) const

pure virtualinherited

Get size of the memory in bytes.

Implemented in stk::StackMemoryWrapper< _StackSize >, stk::StackMemoryWrapper< STACK_SIZE_MIN >, stk::StackMemoryWrapper<(32U)>, stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

GetStackSpace()

virtual size_t stk::IStackMemory::GetStackSpace ( )

inlinevirtualinherited

Get available stack space.

Returns

Number of elements of the stack memory array remaining on the stack (computed via the watermark pattern). Returns 0 if the stack has been fully used or the watermark STK_STACK_MEMORY_FILLER was overwritten.

Warning

Stack type: Bottom to Top (index[0]).

Definition at line 252 of file stk_common.h.

    {
        const Word *stack = GetStack();
        const size_t stack_size = GetStackSize();
 
        // count leading Words equal to STK_STACK_MEMORY_FILLER (watermark)
        size_t space = 0U;
        for ( ; (space < stack_size) && (stack[space] == STK_STACK_MEMORY_FILLER); ++space)
        {}
 
        return space;
    }

References GetStack(), GetStackSize(), and STK_STACK_MEMORY_FILLER.

Referenced by osThreadGetStackSpace().

Here is the call graph for this function:

Here is the caller graph for this function:

GetTraceName()

virtual const char * stk::ITask::GetTraceName ( ) const

pure virtual

Get task trace name set by application.

Returns

Null-terminated name string, or NULL if unused.

Note

Used for debugging and tracing only (e.g. SEGGER SystemView). Kernel does not interpret this value.

Implemented in stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

GetWeight()

virtual int32_t stk::ITask::GetWeight ( ) const

pure virtual

Get static base weight of the task.

Returns

Static weight value of the task (must be non-zero, positive 24-bit number).

See also

SwitchStrategySmoothWeightedRoundRobin, IKernelTask::GetWeight

Implemented in stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

OnDeadlineMissed()

virtual void stk::ITask::OnDeadlineMissed ( uint32_t duration )

pure virtual

Called by the scheduler if deadline of the task is missed when Kernel is operating in Hard Real-Time mode (see stk::KERNEL_HRT).

Parameters

[in]

duration

Elapsed active time in ticks at the point the deadline was detected. Always greater than the task's configured deadline (ticks).

Note

Optional handler. Use it for fault logging.

After this call returns, IPlatform::ProcessHardFault() is invoked and the system enters a safe state. This function should not attempt to recover scheduling.

Implemented in stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

OnExit()

virtual void stk::ITask::OnExit ( )

pure virtual

Called by the kernel before removal from the scheduling (see stk::KERNEL_DYNAMIC).

Note

The task's stack is no longer in use but the ITask object itself is still valid.

The default no-op implementation is sufficient for detached tasks. Override to implement join semantics (signal a waiting joiner).

Called in kernel/tick context - keep it short. ISR-safe primitives only (e.g. stk::sync::Semaphore::Signal(), stk::sync::EventFlags::Set()).

KERNEL_DYNAMIC only. Never called in KERNEL_STATIC mode.

Implemented in stk::Task< _StackSize, _AccessMode >, stk::TaskW< _Weight, _StackSize, _AccessMode >, stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

Referenced by stk::Kernel< stk::KERNEL_DYNAMIC|stk::KERNEL_SYNC, 16U, stk::SwitchStrategyFP32, stk::PlatformDefault >::RemoveTask().

Here is the caller graph for this function:

Run()

virtual void stk::ITask::Run ( )

pure virtual

Entry point of the user task.

Note

Called by the Kernel when the task is scheduled for execution. Implement this method with the task's main logic.

Warning

If Kernel is configured as KERNEL_STATIC, the body must contain an infinite loop.

void Run()
{
    while (true)
    {
        // task logic here
    }
}

Implemented in stk::time::TimerHost::TimerWorkerTask, StkThread, and TaskWrapper.

---

The documentation for this class was generated from the following file:

• stk_common.h