RDMA_CREATE_ID(3) Librdmacm Programmer's Manual RDMA_CREATE_ID(3)NAMErdma_create_id - Allocate a communication identifier.
SYNOPSIS
#include <rdma/rdma_cma.h>
int rdma_create_id (struct rdma_event_channel *channel, struct
rdma_cm_id **id, void *context, enum rdma_port_space ps);
ARGUMENTS
channel The communication channel that events associated with the
allocated rdma_cm_id will be reported on. This may be
NULL.
id A reference where the allocated communication identifier
will be returned.
context User specified context associated with the rdma_cm_id.
ps RDMA port space.
DESCRIPTION
Creates an identifier that is used to track communication information.
RETURN VALUE
Returns 0 on success, or -1 on error. If an error occurs, errno will
be set to indicate the failure reason.
NOTES
Rdma_cm_id's are conceptually equivalent to a socket for RDMA communi‐
cation. The difference is that RDMA communication requires explicitly
binding to a specified RDMA device before communication can occur, and
most operations are asynchronous in nature. Asynchronous communication
events on an rdma_cm_id are reported through the associated event chan‐
nel. If the channel parameter is NULL, the rdma_cm_id will be placed
into synchronous operation. While operating synchronously, calls that
result in an event will block until the operation completes. The event
will be returned to the user through the rdma_cm_id structure, and be
available for access until another rdma_cm call is made.
Users must release the rdma_cm_id by calling rdma_destroy_id.
PORT SPACE
Details of the services provided by the different port spaces are out‐
lined below.
RDMA_PS_TCP
Provides reliable, connection-oriented QP communication. Unlike
TCP, the RDMA port space provides message, not stream, based
communication.
RDMA_PS_UDP
Provides unreliable, connectionless QP communication. Supports
both datagram and multicast communication.
SEE ALSOrdma_cm(7), rdma_create_event_channel(3), rdma_destroy_id(3),
rdma_get_devices(3), rdma_bind_addr(3), rdma_resolve_addr(3), rdma_con‐
nect(3), rdma_listen(3), rdma_set_option(3)librdmacm 2010-07-19 RDMA_CREATE_ID(3)
