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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
xs_send(3)
==========
NAME
----
xs_send - send a message part on a socket
SYNOPSIS
--------
*int xs_send (void '*socket', void '*buf', size_t 'len', int 'flags');*
DESCRIPTION
-----------
The _xs_send()_ function shall queue a message created from the buffer
referenced by the 'buf' and 'len' arguments. The 'flags' argument is
a combination of the flags defined below:
*XS_DONTWAIT*::
Specifies that the operation should be performed in non-blocking mode. If the
message cannot be queued on the 'socket', the _xs_send()_ function shall
fail with 'errno' set to EAGAIN.
*XS_SNDMORE*::
Specifies that the message being sent is a multi-part message, and that further
message parts are to follow. Refer to the section regarding multi-part messages
below for a detailed description.
NOTE: A successful invocation of _xs_send()_ does not indicate that the
message has been transmitted to the network, only that it has been queued on
the 'socket' and Crossroads have assumed responsibility for the message.
Multi-part messages
~~~~~~~~~~~~~~~~~~~
A Crossroads message is composed of 1 or more message parts. Each message
part is an independent 'xs_msg_t' in its own right. Crossroads ensure atomic
delivery of messages; peers shall receive either all _message parts_ of a
message or none at all. The total number of message parts is unlimited except
by available memory.
An application that sends multipart messages must use the _XS_SNDMORE_ flag
when sending each data part except the final one.
RETURN VALUE
------------
The _xs_send()_ function shall return number of bytes in the message
if successful. Otherwise it shall return `-1` and set 'errno' to one of the
values defined below.
ERRORS
------
*EAGAIN*::
Non-blocking mode was requested and the message cannot be sent at the moment.
*ENOTSUP*::
The _xs_send()_ operation is not supported by this socket type.
*EFSM*::
The _xs_send()_ operation cannot be performed on this socket at the moment
due to the socket not being in the appropriate state. This error may occur with
socket types that switch between several states, such as XS_REP. See the
_messaging patterns_ section of linkxs:xs_socket[3] for more information.
*ETERM*::
The 'context' associated with the specified 'socket' was terminated.
*ENOTSOCK*::
The provided 'socket' was invalid.
*EINTR*::
The operation was interrupted by delivery of a signal before the message was
sent.
EXAMPLE
-------
.Sending a multi-part message
----
/* Send a multi-part message consisting of three parts to socket */
rc = xs_send (socket, "ABC", 3, XS_SNDMORE);
assert (rc == 3);
rc = xs_send (socket, "DEFGH", 5, XS_SNDMORE);
assert (rc == 5);
/* Final part; no more parts to follow */
rc = xs_send (socket, "JK", 2, 0);
assert (rc == 2);
----
SEE ALSO
--------
linkxs:xs_sendmsg[3]
linkxs:xs_recv[3]
linkxs:xs_recvmsg[3]
linkxs:xs_socket[7]
linkxs:xs[7]
AUTHORS
-------
+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
|
