iox::roudi::MemoryProvider🔗

This class creates memory which is requested by the MemoryBlocks. Once the memory is available, this is announced to the blocks, so that they can consume the memory for their needs. When the Memory is release, the blocks will also called to handle this appropriately, e.g. calling the destructor of the underlying type. This class is an interface with some default behavior and needs an implementation for real memory supply, e.g. a PosixShmMemoryProvider.

#include <memory_provider.hpp>

Inherited by iox::roudi::PosixShmMemoryProvider

Public Functions🔗

	Name
	MemoryProvider() =default
	~MemoryProvider()
	MemoryProvider(const MemoryProvider & )
	MemoryProvider(MemoryProvider && )
MemoryProvider &	operator=(const MemoryProvider & )
MemoryProvider &	operator=(MemoryProvider && )
cxx::expected< MemoryProviderError >	addMemoryBlock(cxx::not_null< MemoryBlock * > memoryBlock) This function add a MemoryBlock to the list of memory requester.
cxx::expected< MemoryProviderError >	create() With this call the memory requested by the MemoryBlocks need to be created. The function should be called from a MemoryManager which handles one or more MemoryProvider.
void	announceMemoryAvailable() This function announces the availability of the memory to the MemoryBlocks. The function should be called from a MemoryManager which handles one or more MemoryProvider.
cxx::expected< MemoryProviderError >	destroy() This function destroys the previously allocated memory. Before the destruction, all MemoryBlocks are requested to handle this appropriately, e.g. call the destructor of the underlying type. The function should be called from a MemoryManager which handles one or more MemoryProvider.
cxx::optional< void * >	baseAddress() const This function provides the base address of the created memory.
uint64_t	size() const This function provides the size of the created memory.
cxx::optional< uint64_t >	segmentId() const This function provides the segment id of the relocatable memory segment which is owned by the MemoryProvider.
bool	isAvailable() const This function can be used to check if the requested memory is already available.
bool	isAvailableAnnounced() const This function can be used to check if the availability of the memory was announced to the MemoryBlocks.

Protected Functions🔗

	Name
virtual cxx::expected< void *, MemoryProviderError >	createMemory(const uint64_t size, const uint64_t alignment) =0 This function needs to be implemented to provide the actual memory, e.g. in case of POSIX SHM, shm_open and mmap would need to be called in the implementation of this function.
virtual cxx::expected< MemoryProviderError >	destroyMemory() =0 This function needs to be implemented to free the actual memory, e.g. in case of POSIX SHM, shm_unlink and munmap would need to be called in the implementation of this function.
const char *	getErrorString(const MemoryProviderError error)

Friends🔗

	Name
class	RouDiMemoryManager

Public Functions Documentation🔗

function MemoryProvider🔗

MemoryProvider() =default

function ~MemoryProvider🔗

~MemoryProvider()

function MemoryProvider🔗

MemoryProvider(
    const MemoryProvider & 
)

Note: this is intentional not movable/copyable, since a pointer to the memory provider is registered at the RouDiMemoryManager and therefore an instance of a MemoryProvider must be pinned to memory

function MemoryProvider🔗

MemoryProvider(
    MemoryProvider && 
)

function operator=🔗

MemoryProvider & operator=(
    const MemoryProvider & 
)

function operator=🔗

MemoryProvider & operator=(
    MemoryProvider && 
)

function addMemoryBlock🔗

cxx::expected< MemoryProviderError > addMemoryBlock(
    cxx::not_null< MemoryBlock * > memoryBlock
)

This function add a MemoryBlock to the list of memory requester.

Parameters:

memoryBlock is a pointer to a user defined MemoryBlock

Return: an MemoryProviderError::MEMORY_BLOCKS_EXHAUSTED error if no further memory blocks can be added, otherwise success

function create🔗

cxx::expected< MemoryProviderError > create()

With this call the memory requested by the MemoryBlocks need to be created. The function should be called from a MemoryManager which handles one or more MemoryProvider.

Return: an MemoryProviderError if memory allocation was not successful, otherwise success

function announceMemoryAvailable🔗

void announceMemoryAvailable()

This function announces the availability of the memory to the MemoryBlocks. The function should be called from a MemoryManager which handles one or more MemoryProvider.

function destroy🔗

cxx::expected< MemoryProviderError > destroy()

This function destroys the previously allocated memory. Before the destruction, all MemoryBlocks are requested to handle this appropriately, e.g. call the destructor of the underlying type. The function should be called from a MemoryManager which handles one or more MemoryProvider.

Return: an error if memory destruction was not successful, otherwise success

function baseAddress🔗

cxx::optional< void * > baseAddress() const

This function provides the base address of the created memory.

Return: an optional pointer to the base address of the created memory if the memory is available, otherwise a cxx::nullopt_t

function size🔗

uint64_t size() const

This function provides the size of the created memory.

Return: the size of the created memory

function segmentId🔗

cxx::optional< uint64_t > segmentId() const

This function provides the segment id of the relocatable memory segment which is owned by the MemoryProvider.

Return: an optional segment id for the created memory if the memory is available, otherwise cxx::nullopt_t

function isAvailable🔗

bool isAvailable() const

This function can be used to check if the requested memory is already available.

Return: true if the requested memory is available, false otherwise

function isAvailableAnnounced🔗

bool isAvailableAnnounced() const

This function can be used to check if the availability of the memory was announced to the MemoryBlocks.

Return: true if the availability of the memory was announced to the MemoryBlocks, false otherwise

Protected Functions Documentation🔗

function createMemory🔗

virtual cxx::expected< void *, MemoryProviderError > createMemory(
    const uint64_t size,
    const uint64_t alignment
) =0

This function needs to be implemented to provide the actual memory, e.g. in case of POSIX SHM, shm_open and mmap would need to be called in the implementation of this function.

Parameters:

size is the size in bytes for the requested memory, the size should already be calculated according to the alignment requirements
alignment the required alignment for the memory

Return: the pointer of the begin of the created memory or a MemoryProviderError if the memory could not be created

Reimplemented by: iox::roudi::PosixShmMemoryProvider::createMemory

function destroyMemory🔗

virtual cxx::expected< MemoryProviderError > destroyMemory() =0

This function needs to be implemented to free the actual memory, e.g. in case of POSIX SHM, shm_unlink and munmap would need to be called in the implementation of this function.

Return: a MemoryProviderError if the destruction failed, otherwise success

Reimplemented by: iox::roudi::PosixShmMemoryProvider::destroyMemory

function getErrorString🔗

static const char * getErrorString(
    const MemoryProviderError error
)

Friends🔗

friend RouDiMemoryManager🔗

friend class RouDiMemoryManager;

Updated on 31 May 2022 at 15:29:16 CEST