1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
= 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)]
|
