Tribblix: manual page: rsm_memseg_get

RSM_MEMSEG_GET_POLLFD(3RSM) Remote Shared Memory Library Functions

NAME

rsm_memseg_get_pollfd, rsm_memseg_release_pollfd - get or release a
poll descriptor

SYNOPSIS

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

int rsm_memseg_get_pollfd(void *memseg, struct pollfd *fd);

int rsm_memseg_release_pollfd(void *memseg);

DESCRIPTION

The rsm_memseg_get_pollfd() and rsm_memseg_release_pollfd() functions
provide an alternative to rsm_intr_signal_wait(3RSM). The waiting
process can multiplex event waiting using the poll(2) function after
first obtaining a poll descriptor using rsm_memseg_get_pollfd(). The
descriptor can subsequently be released using
rsm_memseg_release_pollfd().

As a result of a call rsm_memseg_get_pollfd(), the specified pollfd
structure is initialized with a descriptor for the specified segment
(memseg) and the event generated by rsm_intr_signal_post(3RSM).
Either an export segment handle or an import segment handle can be
type cast to a void pointer. The pollfd argument can subsequently be
used with the rsm_intr_signal_wait_pollfd(3RSM) function to wait for
the event; it cannot be used with poll(). If memseg references an
export segment, the segment must be currently published. If memseg
references an import segment, the segment must be connected.

The rsm_memseg_reslease_pollfd() function decrements the reference
count of the pollfd structure associated with the specified segment.
A segment unpublish, destroy or unmap operation will fail if the
reference count is non-zero.

RETURN VALUES

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

ERRORS

The rsm_memseg_get_pollfd() and rsm_memseg_release_pollfd() function
can return the following error:

RSMERR_BAD_SEG_HNDL
Invalid segment handle.