Native QF Memory Pool. More...

#include <qmpool.hpp>

Public Member Functions
	QMPool () noexcept
	Default constructor of QP::QMPool.
void	init (void *const poolSto, std::uint_fast32_t const poolSize, std::uint_fast16_t const blockSize) noexcept
	Initializes the native QF memory pool.
void *	get (std::uint_fast16_t const margin, std::uint_fast8_t const qsId) noexcept
	Obtain a memory block from a memory pool.
void	put (void *const block, std::uint_fast8_t const qsId) noexcept
	Recycles a memory block back to a memory pool.
QMPoolSize	getBlockSize () const noexcept
std::uint16_t	getUse () const noexcept
std::uint16_t	getFree () const noexcept
std::uint16_t	getMin () const noexcept
void *	getFromISR (std::uint_fast16_t const margin, std::uint_fast8_t const qsId) noexcept
void	putFromISR (void *const b, std::uint_fast8_t const qsId) noexcept

Private Attributes
void **	m_start
	Start of the memory managed by this memory pool.
void **	m_end
	End of the memory managed by this memory pool.
void **	m_freeHead
QMPoolSize	m_blockSize
	Memory block size [bytes] held by this fixed-size pool.
QMPoolCtr	m_nTot
	Total number of memory blocks in this pool.
QMPoolCtr	m_nFree
	Number of free memory blocks remaining in the pool at this point.
QMPoolCtr	m_nMin
	Minimum number of free blocks ever present in this pool.

Friends
class	QS

Detailed Description

Native QF Memory Pool.

Details
A fixed block-size memory pool is a very fast and efficient data structure for dynamic allocation of fixed block-size chunks of memory. A memory pool offers fast and deterministic allocation and recycling of memory blocks and is not subject to fragmentation.

The QP::QMPool class describes the native QF memory pool, which can be used as the event pool for mutable event allocation, or as a fast, deterministic fixed block-size heap for any other objects in your application.

Note: QP::QMPool contains only data members for managing a memory pool, but does not contain the pool storage, which must be provided externally during the pool initialization.

Definition at line 67 of file qmpool.hpp.

Constructor & Destructor Documentation

◆ QMPool()

QP::QMPool::QMPool ( )

noexcept

Default constructor of QP::QMPool.

Definition at line 48 of file qf_mem.cpp.

Member Function Documentation

◆ init()

void QP::QMPool::init	(	void *const	poolSto,
		std::uint_fast32_t const	poolSize,
		std::uint_fast16_t const	blockSize )

noexcept

Initializes the native QF memory pool.

Details
Initialize a fixed block-size memory pool by providing it with the pool memory to manage, size of this memory, and the block size.

Parameters

[in]	poolSto	pointer to the memory buffer for pool storage
[in]	poolSize	size of the storage buffer in bytes
[in]	blockSize	fixed-size of the memory blocks in bytes

Attention: The caller of QMPool::init() must make sure that the poolSto pointer is properly aligned. In particular, it must be possible to efficiently store a pointer at the location pointed to by poolSto. Internally, the QMPool_init() function rounds up the block size blockSize so that it can fit an integer number of pointers. This is done to achieve proper alignment of the blocks within the pool.

Note: Due to the rounding of block size the actual capacity of the pool might be less than (poolSize / blockSize). You can check the capacity of the pool by calling the QF_getPoolMin() function.; This function uses a potentially long critical section, because it is intended to be called only during the initialization of the system, when timing is not critical.; Many QF ports use memory pools to implement the event pools.

Definition at line 58 of file qf_mem.cpp.

◆ get()

void * QP::QMPool::get	(	std::uint_fast16_t const	margin,
		std::uint_fast8_t const	qsId )

noexcept

Obtain a memory block from a memory pool.

Details
The function allocates a memory block from the pool and returns a pointer to the block back to the caller.

Parameters

[in]	margin	the minimum number of unused blocks still available in the pool after the allocation.
[in]	qsId	QS-id of this state machine (for QS local filter)

Returns: A pointer to a memory block or NULL if no more blocks are available in the memory pool.

Note: This function can be called from any task level or ISR level.; The memory pool me must be initialized before any events can be requested from it. Also, the QMPool_get() function uses internally a QF critical section, so you should be careful not to call it from within a critical section when nesting of critical section is not supported.

Attention: An allocated block must be later returned back to the same pool from which it has been allocated.

Definition at line 121 of file qf_mem.cpp.

◆ put()

void QP::QMPool::put	(	void *const	block,
		std::uint_fast8_t const	qsId )

noexcept

Recycles a memory block back to a memory pool.

Details
Recycle a memory block to the fixed block-size memory pool.

Parameters

[in]	block	pointer to the memory block that is being recycled
[in]	qsId	QS-id of this state machine (for QS local filter)

Attention: The recycled block must be allocated from the same memory pool to which it is returned.

Note: This function can be called from any task level or ISR level.

Definition at line 200 of file qf_mem.cpp.

◆ getBlockSize()

QMPoolSize QP::QMPool::getBlockSize ( ) const

noexcept

Definition at line 269 of file qf_mem.cpp.

◆ getUse()

std::uint16_t QP::QMPool::getUse ( ) const

noexcept

Definition at line 251 of file qf_mem.cpp.

◆ getFree()

std::uint16_t QP::QMPool::getFree ( ) const

noexcept

Definition at line 257 of file qf_mem.cpp.

◆ getMin()

std::uint16_t QP::QMPool::getMin ( ) const

noexcept

Definition at line 263 of file qf_mem.cpp.

◆ getFromISR()

void * QP::QMPool::getFromISR	(	std::uint_fast16_t const	margin,
		std::uint_fast8_t const	qsId )

noexcept

◆ putFromISR()

void QP::QMPool::putFromISR	(	void *const	b,
		std::uint_fast8_t const	qsId )

noexcept

◆ QS

friend class QS

friend

Definition at line 105 of file qmpool.hpp.

Member Data Documentation

◆ m_start

void* * QP::QMPool::m_start

private

Start of the memory managed by this memory pool.

Definition at line 69 of file qmpool.hpp.

◆ m_end

void* * QP::QMPool::m_end

private

End of the memory managed by this memory pool.

Definition at line 70 of file qmpool.hpp.

◆ m_freeHead

void* * QP::QMPool::m_freeHead

private

Definition at line 71 of file qmpool.hpp.

◆ m_blockSize

QMPoolSize QP::QMPool::m_blockSize

private

Memory block size [bytes] held by this fixed-size pool.

Definition at line 72 of file qmpool.hpp.

◆ m_nTot

QMPoolCtr QP::QMPool::m_nTot

private

Total number of memory blocks in this pool.

Definition at line 73 of file qmpool.hpp.

◆ m_nFree

QMPoolCtr QP::QMPool::m_nFree

private

Number of free memory blocks remaining in the pool at this point.

Definition at line 74 of file qmpool.hpp.

◆ m_nMin

QMPoolCtr QP::QMPool::m_nMin

private

Minimum number of free blocks ever present in this pool.

Details
This attribute remembers the low watermark of the pool, which provides a valuable information for sizing event pools. (

See also: QF_getPoolMin()).

Definition at line 75 of file qmpool.hpp.

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


QP/C++ 8.1.2 Real-Time Event Framework

Public Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ QMPool()

Member Function Documentation

◆ init()

◆ get()

◆ put()

◆ getBlockSize()

◆ getUse()

◆ getFree()

◆ getMin()

◆ getFromISR()

◆ putFromISR()

Friends And Related Symbol Documentation

◆ QS

Member Data Documentation

◆ m_start

◆ m_end

◆ m_freeHead

◆ m_blockSize

◆ m_nTot

◆ m_nFree

◆ m_nMin