.TH "RDMA_CREATE_ID" 3 "2007-08-06" "librdmacm" "Librdmacm Programmer's Manual" librdmacm
.SH NAME
rdma_create_id \- Allocate a communication identifier.
.SH SYNOPSIS
.B "#include <rdma/rdma_cma.h>"
.P
.B "int" rdma_create_id
.BI "(struct rdma_event_channel *" channel ","
.BI "struct rdma_cm_id **" id ","
.BI "void *" context ","
.BI "enum rdma_port_space " ps ");"
.SH ARGUMENTS
.IP "channel" 12
The communication channel that events associated with the
allocated rdma_cm_id will be reported on.
.IP "id" 12
A reference where the allocated communication identifier will be
returned.
.IP "context" 12
User specified context associated with the rdma_cm_id.
.IP "ps" 12
RDMA port space.
.SH "DESCRIPTION"
Creates an identifier that is used to track communication information.
.SH "NOTES"
Rdma_cm_id's are conceptually equivalent to a socket for RDMA
communication.  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.  Communication
events on an rdma_cm_id are reported through the associated event
channel.  Users must release the rdma_cm_id by calling rdma_destroy_id.
.SH "PORT SPACE"
Details of the services provided by the different port spaces are outlined
below.
.IP RDMA_PS_TCP
Provides reliable, connection-oriented QP communication.  Unlike TCP, the RDMA
port space provides message, not stream, based communication.
.IP RDMA_PS_UDP
Provides unreliable, connectionless QP communication.  Supports both datagram
and multicast communication.
.SH "SEE ALSO"
rdma_cm(7), rdma_create_event_channel(3), rdma_destroy_id(3), rdma_get_devices(3),
rdma_bind_addr(3), rdma_resolve_addr(3), rdma_connect(3), rdma_listen(3),
rdma_set_option(3)