Buffer Management

Functions that allow for the registration and lookup of user memory. Photon requires the registration, or "pinning", of user buffers before RDMA operations are performed. Once registered, backend-specific metadata may be associated with the internal buffer handles. This private data is accessible via the photon_get_buffer_remote() and photon_get_buffer_private() methods. More...

Files
file	photon_buffer.h

Functions
int	photon_register_buffer (void *addr, uint64_t size)
int	photon_unregister_buffer (void *addr, uint64_t size)
int	photon_get_buffer_private (void *addr, uint64_t size, const struct photon_buffer_priv_t **pptr)
int	photon_get_buffer_remote (photon_rid request, photonBuffer ret_buf)

Detailed Description

Functions that allow for the registration and lookup of user memory. Photon requires the registration, or "pinning", of user buffers before RDMA operations are performed. Once registered, backend-specific metadata may be associated with the internal buffer handles. This private data is accessible via the photon_get_buffer_remote() and photon_get_buffer_private() methods.

Function Documentation

photon_get_buffer_private()

int photon_get_buffer_private	(	void *	addr,
		uint64_t	size,
		const struct photon_buffer_priv_t **	pptr
	)

Get the private metadata associated with a user buffer defined by addr and size.

Parameters

addr	A pointer to the user buffer to query
size	The size of the user buffer in bytes
pptr	A reference to a photon_buffer_priv_t struct pointer that will point to the private buffer data on successful return

Returns

PHOTON_OK on success or an error code

Definition at line 585 of file libphoton.c.

photon_get_buffer_remote()

int photon_get_buffer_remote	(	photon_rid	request,
		photonBuffer	ret_buf
	)

Get the private metadata associated with a remote buffer exchanged using the rendezvous interface and identified by request.

Parameters

request	The request associated with a send/recv buffer
ret_buf	A pointer to a photon_buffer_t struct that will be filled in with the buffer metadata on successful return

Returns

PHOTON_OK on success or an error code

Definition at line 591 of file libphoton.c.

photon_register_buffer()

int photon_register_buffer	(	void *	addr,
		uint64_t	size
	)

Register a user buffer with the Photon library. This must be called before the addr is used in any subsequent Photon RDMA call.

Parameters

addr	A pointer to the user buffer to register
size	The size of the user buffer in bytes

Returns

PHOTON_OK on success or an error code

Definition at line 370 of file libphoton.c.

photon_unregister_buffer()

int photon_unregister_buffer	(	void *	addr,
		uint64_t	size
	)

Unregisters a user buffer that was previously registered with photon_register_buffer(). This method frees the Photon internal buffer handle and private metadata associated with addr and size.

Parameters

addr	A pointer to the user buffer to unregister
size	The size of the user buffer in bytes

Returns

PHOTON_OK on success or an error code

Definition at line 374 of file libphoton.c.