stk::IPlatform Class Reference

Interface for a platform driver. More...

#include <stk_common.h>

Inheritance diagram for stk::IPlatform:

Classes
class	IEventHandler
	Interface for a back-end event handler. More...
class	IEventOverrider
	Interface for a platform event overrider. More...

Public Member Functions
virtual void	Initialize (IEventHandler *event_handler, IKernelService *service, uint32_t resolution_us, Stack *exit_trap)=0
	Initialize scheduler's context.
virtual void	Start ()=0
	Start scheduling.
virtual void	Stop ()=0
	Stop scheduling.
virtual bool	InitStack (EStackType stack_type, Stack *stack, IStackMemory *stack_memory, ITask *user_task)=0
	Initialize stack memory of the user task.
virtual uint32_t	GetTickResolution () const =0
	Get resolution of the system tick timer in microseconds. Resolution means a number of microseconds between system tick timer ISRs.
virtual void	SwitchToNext ()=0
	Switch to a next task.
virtual void	Sleep (Timeout ticks)=0
	Put calling process into a sleep state.
virtual void	SleepUntil (Ticks timestamp)=0
	Put calling process into a sleep state until the specified timestamp.
virtual void	ProcessTick ()=0
	Process one tick.
virtual void	ProcessHardFault ()=0
	Cause a hard fault of the system.
virtual void	SetEventOverrider (IEventOverrider *overrider)=0
	Set platform event overrider.
virtual Word	GetCallerSP () const =0
	Get caller's Stack Pointer (SP).
virtual TId	GetTid () const =0
	Get thread Id.

Detailed Description

Interface for a platform driver.

Note

Bridge design pattern. Do not put implementation details in the header of the concrete class to avoid breaking this pattern.

Platform driver represents an underlying hardware and implements the following logic:

• time tick
• context switching
• hardware access from the user task

All functions are called by the kernel implementation.

Definition at line 574 of file stk_common.h.

Member Function Documentation

GetCallerSP()

virtual Word stk::IPlatform::GetCallerSP ( ) const

pure virtual

Get caller's Stack Pointer (SP).

Note

Valid for a Thread process only.

Returns

Current value of the Stack Pointer (SP) of the calling process.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

GetTickResolution()

virtual uint32_t stk::IPlatform::GetTickResolution ( ) const

pure virtual

Get resolution of the system tick timer in microseconds. Resolution means a number of microseconds between system tick timer ISRs.

Returns

Microseconds.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

GetTid()

virtual TId stk::IPlatform::GetTid ( ) const

pure virtual

Get thread Id.

Returns

Thread Id.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

Initialize()

virtual void stk::IPlatform::Initialize ( IEventHandler * event_handler, IKernelService * service, uint32_t resolution_us, Stack * exit_trap )

pure virtual

Initialize scheduler's context.

Parameters

[in]	event_handler	Event handler.
[in]	service	Kernel service.
[in]	resolution_us	Tick resolution in microseconds (for example 1000 equals to 1 millisecond resolution).
[in]	exit_trap	Stack of the Exit trap (optional, provided if kernel is operating in KERNEL_DYNAMIC mode).

Note

Must be called once before Start().

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

InitStack()

virtual bool stk::IPlatform::InitStack ( EStackType stack_type, Stack * stack, IStackMemory * stack_memory, ITask * user_task )

pure virtual

Initialize stack memory of the user task.

Parameters

[in]	stack_type	Stack type.
[in]	stack	Stack descriptor.
[in]	stack_memory	Stack memory.
[in]	user_task	User task to which Stack belongs.

Returns

true on success, false if the stack memory is too small, misaligned, or the stack type is unsupported.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

ProcessHardFault()

virtual void stk::IPlatform::ProcessHardFault ( )

pure virtual

Cause a hard fault of the system.

Note

Normally called by the Kernel when one of the scheduled tasks missed its deadline (see stk::KERNEL_HRT).

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

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

Here is the caller graph for this function:

ProcessTick()

virtual void stk::IPlatform::ProcessTick ( )

pure virtual

Process one tick.

Note

Normally system tick is processed by the platform driver implementation. In case system tick handler is used by the application and should not be implemented by the driver then disable driver's handler in stk_config.h like this:

#define STK_SYSTICK_HANDLER _STK_SYSTICK_HANDLER_DISABLE

and then call ProcessTick() from your custom tick handler.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

SetEventOverrider()

virtual void stk::IPlatform::SetEventOverrider ( IEventOverrider * overrider )

pure virtual

Set platform event overrider.

Note

Must be set prior call to IKernel::Start.

Parameters

[in]

overrider

Platform event overrider.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

Sleep()

virtual void stk::IPlatform::Sleep ( Timeout ticks )

pure virtual

Put calling process into a sleep state.

Note

Unlike Delay this function does not waste CPU cycles and allows kernel to put CPU into a low-power state.

Parameters

[in]

ticks

Time to sleep (ticks).

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

SleepUntil()

virtual void stk::IPlatform::SleepUntil ( Ticks timestamp )

pure virtual

Put calling process into a sleep state until the specified timestamp.

Note

Unlike Delay this function does not waste CPU cycles and allows kernel to put CPU into a low-power state.

Unsupported in HRT mode (see stk::KERNEL_HRT); in HRT mode tasks sleep automatically according to their periodicity and workload.

Parameters

[in]

timestamp

Absolute timestamp (ticks).

Warning

ISR-unsafe. Calling from an ISR context is not permitted and will trigger an assertion.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

Start()

virtual void stk::IPlatform::Start ( )

pure virtual

Start scheduling.

Note

This function never returns if kernel is initialized as KERNEL_STATIC. Must be called after Initialize().

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

Stop()

virtual void stk::IPlatform::Stop ( )

pure virtual

Stop scheduling.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

SwitchToNext()

virtual void stk::IPlatform::SwitchToNext ( )

pure virtual

Switch to a next task.

Implemented in stk::PlatformArmCortexM, stk::PlatformRiscV, stk::PlatformX86Win32, and stk::test::PlatformTestMock.

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

• stk_common.h