DAT_EP_POST_SEND(3DAT)DAT_EP_POST_SEND(3DAT)NAMEdat_ep_post_send - transfer data to the remote side
SYNOPSIS
cc [ flag... ] file... -ldat [ library... ]
#include <dat/udat.h>
DAT_RETURN
dat_ep_post_send (
IN DAT_EP_HANDLE ep_handle,
IN DAT_COUNT num_segments,
IN DAT_LMR_TRIPLET *local_iov,
IN DAT_DTO_COOKIE user_cookie,
IN DAT_COMPLETION_FLAGS completion_flags
)
PARAMETERS
ep_handle
Handle for an instance of the Endpoint.
num_segments
Number of lmr_triplets in local_iov. Can be 0 for 0
size message.
local_iov
I/O Vector that specifies the local buffer that
contains data to be transferred. Can be NULL for 0
size message.
user_cookie:
User-provided cookie that is returned to the Con‐
sumer at the completion of the send. Can be NULL.
completion_flags
Flags for posted Send. The default DAT_COMPLE‐
TION_DEFAULT_FLAG is 0x00. Other values are as
follows:
Completion Suppression
DAT_COMPLETION_SUP‐
PRESS_FLAG
0x01
Suppress suc‐
cessful Com‐
pletion.
Solicited Wait
DAT_COMPLE‐
TION_SOLICITED_WAIT_FLAG
0x02
Request for
notification
completion
for matching
receive on
the other
side of the
connection.
Notification of Completion
DAT_COMPLE‐
TION_UNSIGNALLED_FLAG
0x04
Non-notifica‐
tion comple‐
tion. Local
Endpoint must
be configured
for Notifica‐
tion Suppres‐
sion.
Barrier Fence
DAT_COMPLETION_BAR‐
RIER_FENCE_FLAG
0x08
Request for
Barrier
Fence.
DESCRIPTION
The dat_ep_post_send() function requests a transfer of all the data
from the local_iov over the connection of the ep_handle Endpoint to the
remote side.
The num_segments parameter specifies the number of segments in the
local_iov. The local_iov segments are traversed in the I/O Vector order
until all the data is transferred.
A Consumer cannot modify the local_iov or its content until the DTO is
completed. When a Consumer does not adhere to this rule, the behavior
of the Provider and the underlying Transport is not defined. Providers
that allow Consumers to get ownership of the local_iov back after the
dat_ep_post_send() returns should document this behavior and also spec‐
ify its support in Provider attributes. This behavior allows Consumers
full control of the local_iov, but not the memory it specifies after
dat_ep_post_send() returns. Because this behavior is not guaranteed by
all Providers, portable Consumers should not rely on this behavior.
Consumers should not rely on the Provider copying local_iov informa‐
tion.
The DAT_SUCCESS return of the dat_ep_post_send() is at least the equiv‐
alent of posting a Send operation directly by native Transport.
Providers should avoid resource allocation as part of
dat_ep_post_send() to ensure that this operation is nonblocking and
thread safe for an UpCall.
The completion of the posted Send is reported to the Consumer asyn‐
chronously through a DTO Completion event based on the specified com‐
pletion_flags value. The value of DAT_COMPLETION _UNSIGNALLED_FLAG is
only valid if the Endpoint Request Completion Flags DAT_COMPLE‐
TION_UNSIGNALLED_FLAG. Otherwise, DAT_INVALID_PARAMETER is returned.
The user_cookie allows Consumers to have unique identifiers for each
DTO. These identifiers are completely under user control and are
opaque to the Provider. There is no requirement on the Consumer that
the value user_cookie should be unique for each DTO. The user_cookie is
returned to the Consumer in the Completion event for the posted Send.
The operation is valid for the Endpoint in the DAT_EP_STATE_CONNECTED
and DAT_EP_STATE_DISCONNECTED states. If the operation returns success‐
fully for the Endpoint in the DAT_EP_STATE_DISCONNECTED state, the
posted Send is immediately flushed to request_evd_handle.
RETURN VALUES
DAT_SUCCESS
The operation was successful.
DAT_INSUFFICIENT_RESOURCES
The operation failed due to resource lim‐
itations.
DAT_INVALID_PARAMETER
Invalid parameter. For example, one of
the IOV segments pointed to a memory out‐
side its LMR.
DAT_INVALID_HANDLE
The ep_handle parameter is invalid.
DAT_INVALID_STATE
A parameter is in an invalid state. End‐
point was not in the DAT_EP_STATE_CON‐
NECTED or DAT_EP_STATE_DISCONNECTED
state.
DAT_PROTECTION_VIOLATION
Protection violation for local or remote
memory access. Protection Zone mismatch
between an LMR of one of the local_iov
segments and the local Endpoint.
DAT_PRIVILEGES_VIOLATION
Privileges violation for local or remote
memory access. One of the LMRs used in
local_iov was either invalid or did not
have the local read privileges.
USAGE
For best Send operation performance, the Consumer should align each
buffer segment of local_iov to the Optimal Buffer Alignment attribute
of the Provider. For portable applications, the Consumer should align
each buffer segment of local_iov to the DAT_OPTIMAL_ALIGNMENT.
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 ALSOlibdat(3LIB), attributes(5)
Jul 16, 2004 DAT_EP_POST_SEND(3DAT)