DAT_CR_ACCEPT(3DAT) Direct Access Transport Library Functions


NAME


dat_cr_accept - establishes a Connection between the active remote side
requesting Endpoint and the passive side local Endpoint

SYNOPSIS


cc [ flag... ] file... -ldat [ library... ]
#include <dat/udat.h>

DAT_RETURN
dat_cr_accept (
IN DAT_CR_HANDLE cr_handle,
IN DAT_EP_HANDLE ep_handle,
IN DAT_COUNT private_data_size,
IN const DAT_PVOID private_data
)


PARAMETERS


cr_handle
Handle to an instance of a Connection Request that
the Consumer is accepting.


ep_handle
Handle for an instance of a local Endpoint that the
Consumer is accepting the Connection Request on. If
the local Endpoint is specified by the Connection
Request, the ep_handle shall be DAT_HANDLE_NULL.


private_data_size
Size of the private_data, which must be nonnegative.


private_data
Pointer to the private data that should be provided
to the remote Consumer when the Connection is
established. If private_data_size is zero, then
private_data can be NULL.


DESCRIPTION


The dat_cr_accept() function establishes a Connection between the active
remote side requesting Endpoint and the passive side local Endpoint. The
local Endpoint is either specified explicitly by ep_handle or implicitly
by a Connection Request. In the second case, ep_handle is
DAT_HANDLE_NULL.


Consumers can specify private data that is provided to the remote side
upon Connection establishment.


If the provided local Endpoint does not satisfy the requested Connection
Request, the operation fails without any effect on the local Endpoint,
Pending Connection Request, private data, or remote Endpoint.


The operation is asynchronous. The successful completion of the operation
is reported through a Connection Event of type
DAT_CONNECTION_EVENT_ESTABLISHED on the connect_evd of the local
Endpoint.


If the Provider cannot complete the Connection establishment, the
connection is not established and the Consumer is notified through a
Connection Event of type DAT_CONNECTION_EVENT_ACCEPT_COMPLETION_ERROR on
the connect_evd of the local Endpoint. It can be caused by the active
side timeout expiration, transport error, or any other reason. If
Connection is not established, Endpoint transitions into Disconnected
state and all posted Recv DTOs are flushed to its recv_evd_handle.


This operation, if successful, also destroys the Connection Request
instance. Use of the handle of the destroyed cr_handle in any consequent
operation fails.

RETURN VALUES


DAT_SUCCESS
The operation was successful.


DAT_INVALID_HANDLE
The cr_handle or ep_handle parameter is invalid.


DAT_INVALID_PARAMETER
The private_data_size or private_data parameter
is invalid, out of range, or a combination of
parameters was invalid


USAGE


Consumers should be aware that Connection establishment might fail in the
following cases: If the accepting Endpoint has an outstanding RDMA Read
outgoing attribute larger than the requesting remote Endpoint or
outstanding RDMA Read incoming attribute, or if the outstanding RDMA Read
incoming attribute is smaller than the requesting remote Endpoint or
outstanding RDMA Read outgoing attribute.


Consumers should set the accepting Endpoint RDMA Reads as the target
(incoming) to a number larger than or equal to the remote Endpoint RDMA
Read outstanding as the originator (outgoing), and the accepting Endpoint
RDMA Reads as the originator to a number smaller than or equal to the
remote Endpoint RDMA Read outstanding as the target. DAT API does not
define a protocol on how remote peers exchange Endpoint attributes. The
exchange of outstanding RDMA Read incoming and outgoing attributes of EPs
is left to the Consumer ULP. Consumer can use Private Data for it.


If the Consumer does not care about posting RDMA Read operations or
remote RDMA Read operations on the connection, it can set the two
outstanding RDMA Read attribute values to 0.


If the Consumer does not set the two outstanding RDMA Read attributes of
the Endpoint, the Provider is free to pick up any value for default. The
Provider can change these default values during connection setup.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+---------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+---------------------------+
|Interface Stability | Standard: uDAPL, 1.1, 1.2 |
+--------------------+---------------------------+
|MT-Level | Unsafe |
+--------------------+---------------------------+

SEE ALSO


libdat(3LIB), attributes(5)


July 16, 2004 DAT_CR_ACCEPT(3DAT)