68 lines
1.9 KiB
Text
68 lines
1.9 KiB
Text
|
= nng_aio_set_iov(3)
|
||
|
|
//
|
||
|
|
// Copyright 2021 Staysail Systems, Inc. <info@staysail.tech>
|
||
|
|
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
|
||
|
|
//
|
||
|
|
// This document is supplied under the terms of the MIT License, a
|
||
|
|
// copy of which should be located in the distribution where this
|
||
|
|
// file was obtained (LICENSE.txt). A copy of the license may also be
|
||
|
|
// found online at https://opensource.org/licenses/MIT.
|
||
|
|
//
|
||
|
|
|
||
|
|
== NAME
|
||
|
|
|
||
|
|
nng_aio_set_iov - set scatter/gather vector
|
||
|
|
|
||
|
|
== SYNOPSIS
|
||
|
|
|
||
|
|
[source,c]
|
||
|
|
----
|
||
|
|
#include <nng/nng.h>
|
||
|
|
|
||
|
|
int nng_aio_set_iov(nng_aio *aio, unsigned int niov, nng_iov *iov);
|
||
|
|
----
|
||
|
|
|
||
|
|
== DESCRIPTION
|
||
|
|
|
||
|
|
The `nng_aio_set_iov()` function sets a ((scatter/gather)) vector _iov_ on the handle _aio_.
|
||
|
|
|
||
|
|
The _iov_ is a pointer to an array of _niov_ xref:nng_iov.5.adoc[`nng_iov`]
|
||
|
|
structures, which have the following definition:
|
||
|
|
|
||
|
|
[source,c]
|
||
|
|
----
|
||
|
|
typedef struct nng_iov {
|
||
|
|
void * iov_buf;
|
||
|
|
size_t iov_len;
|
||
|
|
};
|
||
|
|
----
|
||
|
|
|
||
|
|
The _iov_ is copied into storage in the _aio_ itself, so that callers may use stack allocated `nng_iov` structures.
|
||
|
|
The values pointed to by the `iov_buf` members are *not* copied by this function though.
|
||
|
|
|
||
|
|
A maximum of four (4) `nng_iov` members may be supplied.
|
||
|
|
|
||
|
|
NOTE: Earlier versions of the library could accept longer scatter-gather lists.
|
||
|
|
However, no known consumers have ever needed a scatter-gather list longer than 4 vectors.
|
||
|
|
As a result, the implementation limit was reduced, and heap allocations which could fail were removed.
|
||
|
|
|
||
|
|
== RETURN VALUES
|
||
|
|
|
||
|
|
This function returns 0 on success, and non-zero otherwise.
|
||
|
|
|
||
|
|
== ERRORS
|
||
|
|
|
||
|
|
[horizontal]
|
||
|
|
`NNG_EINVAL`:: Value of specified _niov_ is too large.
|
||
|
|
|
||
|
|
== SEE ALSO
|
||
|
|
|
||
|
|
[.text-left]
|
||
|
|
xref:nng_aio_alloc.3.adoc[nng_aio_alloc(3)],
|
||
|
|
xref:nng_aio_cancel.3.adoc[nng_aio_cancel(3)],
|
||
|
|
xref:nng_aio_count.3.adoc[nng_aio_count(3)],
|
||
|
|
xref:nng_aio_result.3.adoc[nng_aio_result(3)],
|
||
|
|
xref:nng_aio.5.adoc[nng_aio(5)],
|
||
|
|
xref:nng_iov.5.adoc[nng_iov(5)],
|
||
|
|
xref:nng.7.adoc[nng(7)]
|