Realm::SharedMemoryInfo Class Reference

Holds a reference to a mapped shared memory region and all the information used to create/open it. Such shared memory region can be shared with other processes on the same system using a communication mechanism such as via unix domain sockets, win32 DuplicateHandle, or if names are used, transferring the names to the processes and opening them (. More...

#include <shm.h>

Public Member Functions
	SharedMemoryInfo (void)
	~SharedMemoryInfo (void)
	On destruction, the SharedMemoryInfo will unmap the memory associated with this shared region, if any, and unlink it from the file system if it owns it.
	SharedMemoryInfo (const SharedMemoryInfo &)=delete
SharedMemoryInfo &	operator= (const SharedMemoryInfo &)=delete
void	unlink (void)
	Removes the name from the shared memory region such that it can't be opened by it's name any more and closes the associated handle.
Move semantics
	SharedMemoryInfo (SharedMemoryInfo &&other)
SharedMemoryInfo &	operator= (SharedMemoryInfo &&other)
Accessors
template<typename T >
T *	get_ptr () const
OsHandle	get_handle () const
size_t	get_size () const
std::string	get_name () const
	operator bool () const

Static Public Member Functions
static bool	create (SharedMemoryInfo &info, size_t size, const char *name=nullptr, int numa_node=-1)
	Creates a shared memory region accessible via handle.
static bool	open (SharedMemoryInfo &info, const std::string &name, size_t size)
	Opens a previously created shared memory region given it's name and size.
static bool	open (SharedMemoryInfo &info, OsHandle handle, size_t size)
	Opens a previously created shared memory region given it's associated handle and size.

Detailed Description

Holds a reference to a mapped shared memory region and all the information used to create/open it. Such shared memory region can be shared with other processes on the same system using a communication mechanism such as via unix domain sockets, win32 DuplicateHandle, or if names are used, transferring the names to the processes and opening them (.

See also

SharedMemoryInfo::open)

Constructor & Destructor Documentation

SharedMemoryInfo() [1/3]

Realm::SharedMemoryInfo::SharedMemoryInfo

(

void

)

SharedMemoryInfo() [2/3]

Realm::SharedMemoryInfo::SharedMemoryInfo

(

SharedMemoryInfo &&

other

)

~SharedMemoryInfo()

Realm::SharedMemoryInfo::~SharedMemoryInfo

(

void

)

On destruction, the SharedMemoryInfo will unmap the memory associated with this shared region, if any, and unlink it from the file system if it owns it.

SharedMemoryInfo() [3/3]

Realm::SharedMemoryInfo::SharedMemoryInfo ( const SharedMemoryInfo &  )

delete

Member Function Documentation

create()

static bool Realm::SharedMemoryInfo::create ( SharedMemoryInfo &  info, size_t  size, const char *  name = nullptr, int  numa_node = -1  )

static

Creates a shared memory region accessible via handle.

Note

It is preferred that the name is null here as this creates an anonymous backing store that requires processor-to-processor communication.

Parameters

[out]	info	Shared memory object containing the base pointer and size
	name	Name associated with the shared memory allocation, passed to

See also

SharedMemoryInfo::open in another process.

Parameters

size	Size of the shared memory region to allocate
numa_node	NUMA node to allocate the pages on

Returns

True on success, false otherwise

get_handle()

OsHandle Realm::SharedMemoryInfo::get_handle ( ) const

inline

get_name()

std::string Realm::SharedMemoryInfo::get_name ( ) const

inline

get_ptr()

template<typename T >

T * Realm::SharedMemoryInfo::get_ptr ( ) const

inline

get_size()

size_t Realm::SharedMemoryInfo::get_size ( ) const

inline

open() [1/2]

static bool Realm::SharedMemoryInfo::open ( SharedMemoryInfo &  info, const std::string &  name, size_t  size  )

static

Opens a previously created shared memory region given it's name and size.

Parameters

[out]	info	Shared memory object containing the base pointer and size
	name	Name of the shared memory region (to be retrieved from

See also

SharedMemoryInfo::create in another process)

Parameters

size	Size of the shared memory region to allocate

Returns

True on success, false otherwise

open() [2/2]

static bool Realm::SharedMemoryInfo::open ( SharedMemoryInfo &  info, OsHandle  handle, size_t  size  )

static

Opens a previously created shared memory region given it's associated handle and size.

See also

Realm::close_handle

Parameters

[out]	info
	handle	OS handle of the associated memory object (retrieved from

See also

SharedMemoryInfo::create)

Parameters

size	Size of the shared memory region to allocate

Returns

True on success, false otherwise

operator bool()

Realm::SharedMemoryInfo::operator bool ( ) const

inlineexplicit

operator=() [1/2]

SharedMemoryInfo & Realm::SharedMemoryInfo::operator= ( const SharedMemoryInfo &  )

delete

operator=() [2/2]

SharedMemoryInfo & Realm::SharedMemoryInfo::operator=

(

SharedMemoryInfo &&

other

)

unlink()

void Realm::SharedMemoryInfo::unlink

(

void

)

Removes the name from the shared memory region such that it can't be opened by it's name any more and closes the associated handle.

Note

not applicable to windows

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

• /home/runner/work/realm/realm/realm-src/src/realm/shm.h