os::rtos::thread::stack Class Reference

Thread stack. More...

#include <cmsis-plus/rtos/os.h>

Public Types
using	allocation_element_t = os::rtos::port::stack::allocation_element_t
	Type of a stack allocation element.
using	element_t = os::rtos::port::stack::element_t
	Type of a stack element.

Public Member Functions
Constructors & Destructor
	stack ()
	Construct a thread stack object instance.
	~stack ()=default
	Destruct the stack object instance.
Public Member Functions
void	clear (void)
	Clear the stack pointer and size.
void	set (stack::element_t *address, std::size_t size_bytes)
	Set the stack address and size.
void	initialize (void)
	Align the pointers and initialise to a known pattern.
stack::element_t *	bottom (void)
	Get the stack lowest reserved address.
stack::element_t *	top (void)
	Get the top stack address.
std::size_t	size (void)
	Get the stack size.
bool	check_bottom_magic (void)
	Check if bottom magic word is still there.
bool	check_top_magic (void)
	Check if top magic word is still there.
std::size_t	available (void)
	Compute how much available stack remains.

Static Public Member Functions
Public Static Member Functions
static std::size_t	min_size (void)
	Get the min stack size.
static std::size_t	min_size (std::size_t size_bytes)
	Set the min stack size.
static std::size_t	default_size (void)
	Get the default stack size.
static std::size_t	default_size (std::size_t size_bytes)
	Set the default stack size.

Static Public Attributes
static const element_t	magic = os::rtos::port::stack::magic

Detailed Description

This class does not contain the stack space itself, it is allocated outside, but stores the address and the size of the stack.

It also manages the global variables storing the min and default stack sizes.

Definition at line 432 of file os-thread.h.

Member Typedef Documentation

allocation_element_t

using os::rtos::thread::stack::allocation_element_t = os::rtos::port::stack::allocation_element_t

For alignment reasons, the stack is allocated in larger chunks, usually 8-bytes long on Cortex-M cores.

Definition at line 451 of file os-thread.h.

element_t

using os::rtos::thread::stack::element_t = os::rtos::port::stack::element_t

The stack is organised as an array of platform words (usually 4-bytes long on Cortex-M cores).

Definition at line 442 of file os-thread.h.

Constructor & Destructor Documentation

stack()

os::rtos::thread::stack::stack ( )

inline

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 2122 of file os-thread.h.

    {
      clear ();
    }

~stack()

os::rtos::thread::stack::~stack ( )

default

Member Function Documentation

available()

std::size_t os::rtos::thread::stack::available

(

void

)

Parameters

None.

Returns

Number of available bytes.

Count the number of bytes where the magic is still there.

Warning

: For large stacks it may be an expensive operation.

Cannot be invoked from Interrupt Service Routines.

Definition at line 202 of file os-thread.cpp.

    {
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wunsafe-buffer-usage"
#endif
      element_t* p = bottom_address_;
      std::size_t count = 0;
      while (*p == magic)
        {
          count += sizeof (element_t);
          ++p;
        }
#pragma GCC diagnostic pop
 
      return count;
    }

Referenced by os_terminate_goodbye().

bottom()

thread::stack::element_t * os::rtos::thread::stack::bottom ( void  )

inline

Parameters

None.

Returns

The address of the stack reserved area.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2152 of file os-thread.h.

    {
      return bottom_address_;
    }

check_bottom_magic()

bool os::rtos::thread::stack::check_bottom_magic ( void  )

inline

Parameters

None.

Return values

true	The magic word is still there.
false	The magic word was overwritten.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2184 of file os-thread.h.

    {
      return *bottom () == stack::magic;
    }

References magic.

check_top_magic()

bool os::rtos::thread::stack::check_top_magic ( void  )

inline

Parameters

None.

Return values

true	The magic word is still there.
false	The magic word was overwritten.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2193 of file os-thread.h.

    {
      return *top () == stack::magic;
    }

References magic.

clear()

void os::rtos::thread::stack::clear ( void  )

inline

Parameters

None.

Returns

Nothing

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 2131 of file os-thread.h.

    {
      bottom_address_ = nullptr;
      size_bytes_ = 0;
    }

default_size() [1/2]

std::size_t os::rtos::thread::stack::default_size ( std::size_t  size_bytes )

inlinestatic

Parameters

[in]

size_bytes

Default stack size in bytes.

Returns

The previous value of the default stack size in bytes.

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 2231 of file os-thread.h.

    {
      assert (size_bytes != 0);
      assert (size_bytes >= min_size_bytes_);
 
      std::size_t tmp = default_size_bytes_;
      default_size_bytes_ = size_bytes;
      return tmp;
    }

default_size() [2/2]

std::size_t os::rtos::thread::stack::default_size ( void  )

inlinestatic

Parameters

None.

Returns

The default stack size in bytes.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2222 of file os-thread.h.

    {
      return default_size_bytes_;
    }

Referenced by os::rtos::thread::thread(), os_thread_stack_get_default_size(), and os_thread_stack_set_default_size().

initialize()

void os::rtos::thread::stack::initialize

(

void

)

Parameters

None.

Returns

Nothing.

min_size() [1/2]

std::size_t os::rtos::thread::stack::min_size ( std::size_t  size_bytes )

inlinestatic

Parameters

[in]

size_bytes

Minimum stack size in bytes.

Returns

The previous value of the min stack size in bytes.

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 2211 of file os-thread.h.

    {
      std::size_t tmp = min_size_bytes_;
      min_size_bytes_ = size_bytes;
      return tmp;
    }

min_size() [2/2]

std::size_t os::rtos::thread::stack::min_size ( void  )

inlinestatic

Parameters

None.

Returns

The min stack size in bytes.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2202 of file os-thread.h.

    {
      return min_size_bytes_;
    }

Referenced by os::rtos::thread::thread(), os_thread_stack_get_min_size(), and os_thread_stack_set_min_size().

set()

void os::rtos::thread::stack::set ( stack::element_t *  address, std::size_t  size_bytes  )

inline

Parameters

[in]	address	Bottom stack address.
[in]	size_bytes	Reserved stack size, in bytes.

Parameters

None.

Returns

Nothing

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 2141 of file os-thread.h.

    {
      assert (size_bytes >= min_size_bytes_);
      bottom_address_ = address;
      size_bytes_ = size_bytes;
    }

Referenced by _start().

size()

std::size_t os::rtos::thread::stack::size ( void  )

inline

Parameters

None.

Returns

The stack size in bytes.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2175 of file os-thread.h.

    {
      return size_bytes_;
    }

Referenced by os_terminate_goodbye().

top()

thread::stack::element_t * os::rtos::thread::stack::top ( void  )

inline

Parameters

None.

Returns

The address after the last stack element.

Note

Can be invoked from Interrupt Service Routines.

Definition at line 2161 of file os-thread.h.

    {
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wunsafe-buffer-usage"
#endif
      return bottom_address_ + (size_bytes_ / sizeof (element_t));
#pragma GCC diagnostic pop
    }

Member Data Documentation

magic

const element_t os::rtos::thread::stack::magic = os::rtos::port::stack::magic

static

Definition at line 454 of file os-thread.h.

Referenced by check_bottom_magic(), and check_top_magic().

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

• os-thread.h
• os-thread.cpp