Tribblix: manual page: rsm_memseg_import

RSM_MEMSEG_IMPORT_GET(3RSM) Remote Shared Memory Library Functions

NAME

rsm_memseg_import_get, rsm_memseg_import_get8,
rsm_memseg_import_get16, rsm_memseg_import_get32,
rsm_memseg_import_get64 - read from a segment

SYNOPSIS

cc [ flag... ] file... -lrsm [ library... ]
#include <rsmapi.h>

int rsm_memseg_import_get(rsm_memseg_import_handle_t im_memseg,
off_t offset, void *dest_addr, size_t length);

int rsm_memseg_import_get8(rsm_memseg_import_handle_t im_memseg,
off_t offset, uint8_t *datap, ulong_t rep_cnt);

int rsm_memseg_import_get16(rsm_memseg_import_handle_t im_memseg,
off_t offset, uint16_t *datap, ulong_t rep_cnt);

int rsm_memseg_import_get32(rsm_memseg_import_handle_t im_memseg,
off_t offset, uint32_t *datap, ulong_t rep_cnt);

int rsm_memseg_import_get64(rsm_memseg_import_handle_t im_memseg,
off_t offset, uint64_t *datap, ulong_t rep_cnt);

DESCRIPTION

When using interconnects that allow memory mapping (see
rsm_memseg_import_map(3RSM)), standard CPU memory operations may be
used for accessing memory of a segment. If a mapping is not provided,
then explicitly calling these functions facilitates reading from a
segment. Depending on the attributes of the extension library of the
specific interconnect, these functions may involve performing an
implicit mapping before performing the data transfer. Applications
can be made interconnect-independent with respect to segment reads by
using these functions. The data access error detection is performed
through the use of barriers (see
rsm_memseg_import_open_barrier(3RSM)). The default barrier operation
mode is RSM_BARRIER_MODE_IMPLICIT, meaning that around every get
operation open and close barrier are performed automatically.
Alternatively, explicit error handling may be set up for these
functions (see rsm_memseg_import_set_mode(3RSM)). In either case the
barrier should be initialized prior to using these functions using
rsm_memseg_import_init_barrier(3RSM).

The rsm_memseg_import_get() function copies length bytes from the
imported segment im_memseg beginning at location offset from the
start of the segment to a local memory buffer pointed to by
dest_addr.

The rsm_memseg_import_get8() function copies rep_cnt number of 8-bit
quantities from successive locations starting from offset in the
imported segment to successive local memory locations pointed to by
datap.

The rsm_memseg_import_get16() functions copies rep_cnt number of
16-bit quantities from successive locations starting from offset in
the imported segment to successive local memory locations pointed to
by datap. The offset must be aligned at half-word address boundary.

The rsm_memseg_import_get32() function copies rep_cnt number of
32-bit quantities from successive locations starting from offset in
the imported segment to successive local memory locations pointed to
by datap. The offset must be aligned at word address boundary.

The rsm_memseg_import_get64() function copies rep_cnt number of -bit
quantities from successive locations starting from offset in the
imported segment to successive local memory locations pointed to by
datap. The offset must be aligned at double-word address boundary.

The data transfer functions that transfer small quantities of data
(that is, 8-, 16-, 32-, and 64-bit quantities) perform byte swapping
prior to the data transfer, in the event that the source and
destination have incompatible endian characteristics.

RETURN VALUES

Upon successful completion, these functions return 0. Otherwise, an
error value is returned to indicate the error.

ERRORS

These functions can return the following errors:

RSMERR_BAD_SEG_HNDL

Invalid segment handle.

RSMERR_BAD_ADDR

Bad address.

RSMERR_BAD_MEM_ALIGNMENT

Invalid memory alignment for pointer.

RSMERR_BAD_OFFSET

Invalid offset.

RSMERR_BAD_LENGTH

Invalid length.

RSMERR_PERM_DENIED

Permission denied.

RSMERR_INSUFFICIENT_RESOURCES

Insufficient resources.

RSMERR_BARRIER_UNINITIALIZED

Barrier not initialized.

RSMERR_BARRIER_FAILURE

I/O completion error.

RSMERR_CONN_ABORTED

Connection aborted.