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
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
---
version: tip
layout: manpage_v2
title: nng_pipe_notify(3)
---
<h1>nng_pipe_notify(3)</h1>
<div class="sect1">
<h2 id="_name">NAME</h2>
<div class="sectionbody">
<div class="paragraph">
<p>nng_pipe_notify - register pipe notification callback</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_synopsis">SYNOPSIS</h2>
<div class="sectionbody">
<div class="listingblock">
<div class="content">
<pre class="pygments highlight"><code data-lang="c"><span></span><span class="tok-cp">#include</span><span class="tok-w"> </span><span class="tok-cpf"><nng/nng.h></span>
<span class="tok-k">typedef</span><span class="tok-w"> </span><span class="tok-k">enum</span><span class="tok-w"> </span><span class="tok-p">{</span>
<span class="tok-w"> </span><span class="tok-n">NNG_PIPE_EV_ADD_PRE</span><span class="tok-p">,</span>
<span class="tok-w"> </span><span class="tok-n">NNG_PIPE_EV_ADD_POST</span><span class="tok-p">,</span>
<span class="tok-w"> </span><span class="tok-n">NNG_PIPE_EV_REM_POST</span><span class="tok-p">,</span>
<span class="tok-p">}</span><span class="tok-w"> </span><span class="tok-n">nng_pipe_ev</span><span class="tok-p">;</span>
<span class="tok-k">typedef</span><span class="tok-w"> </span><span class="tok-kt">void</span><span class="tok-w"> </span><span class="tok-p">(</span><span class="tok-o">*</span><span class="tok-n">nng_pipe_cb</span><span class="tok-p">)(</span><span class="tok-n">nng_pipe</span><span class="tok-p">,</span><span class="tok-w"> </span><span class="tok-n">nng_pipe_ev</span><span class="tok-p">,</span><span class="tok-w"> </span><span class="tok-kt">void</span><span class="tok-w"> </span><span class="tok-o">*</span><span class="tok-p">);</span>
<span class="tok-kt">int</span><span class="tok-w"> </span><span class="tok-nf">nng_pipe_notify</span><span class="tok-p">(</span><span class="tok-n">nng_socket</span><span class="tok-w"> </span><span class="tok-n">s</span><span class="tok-p">,</span><span class="tok-w"> </span><span class="tok-n">nng_pipe_ev</span><span class="tok-w"> </span><span class="tok-n">ev</span><span class="tok-p">,</span><span class="tok-w"> </span><span class="tok-n">nng_pipe_cb</span><span class="tok-w"> </span><span class="tok-n">cb</span><span class="tok-p">,</span><span class="tok-w"> </span><span class="tok-kt">void</span><span class="tok-w"> </span><span class="tok-o">*</span><span class="tok-n">arg</span><span class="tok-p">);</span></code></pre>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_description">DESCRIPTION</h2>
<div class="sectionbody">
<div class="paragraph">
<p>The <code>nng_pipe_notify()</code> function registers the callback function <em>cb</em>
to be called whenever a <a href="nng_pipe.5.html">pipe</a> the pipe event specified by
<em>ev</em> occurs on the socket <em>s</em>.
The callback <em>cb</em> will be passed <em>arg</em> as its final argument.</p>
</div>
<div class="paragraph">
<p>A different callback may be supplied for each event.
Each event may have at most one callback registered.
Registering a callback implicitly unregisters any previously registered.</p>
</div>
<div class="paragraph">
<p>The following pipe events are supported:</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1"><code>NNG_PIPE_EV_ADD_PRE</code></dt>
<dd>
<p>This event occurs after a connection and negotiation
has completed, but before the pipe is added to the socket.
If the pipe is closed (using <a href="nng_pipe_close.3.html"><code>nng_pipe_close()</code></a>) at
this point, the socket will never see the pipe, and no further events will
occur for the given pipe.</p>
</dd>
<dt class="hdlist1"><code>NNG_PIPE_EV_ADD_POST</code></dt>
<dd>
<p>This event occurs after the pipe is fully added to
the socket.
Prior to this time, it is not possible to communicate over the pipe with
the socket.</p>
</dd>
<dt class="hdlist1"><code>NNG_PIPE_EV_REM_POST</code></dt>
<dd>
<p>This event occurs after the pipe has been removed
from the socket.
The underlying transport may be closed at this point, and it is not
possible communicate using this pipe.</p>
</dd>
</dl>
</div>
<div class="admonitionblock warning">
<table>
<tr>
<td class="icon">
<i class="fa icon-warning" title="Warning"></i>
</td>
<td class="content">
The callback <em>cb</em> function must <strong>not</strong> attempt to perform any
accesses to the socket, as it is called with a lock on the socket held!
Doing so would thus result in a deadlock.
</td>
</tr>
</table>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
The callback <em>cb</em> may close a pipe for any reason by simply closing
it using <a href="nng_pipe_close.3.html"><code>nng_pipe_close()</code></a>.
This might be done before the pipe is added to the socket (during
<code>NNG_PIPE_EV_ADD_PRE</code>), for example, if the remote peer is not authorized.
</td>
</tr>
</table>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
It is possible to register the same <em>cb</em> and <em>arg</em> for different events
by calling this function separately for different values of <em>ev</em>.
</td>
</tr>
</table>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
This function ignores invalid values for <em>ev</em>.
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_return_values">RETURN VALUES</h2>
<div class="sectionbody">
<div class="paragraph">
<p>This function returns 0 on success, and non-zero otherwise.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_errors">ERRORS</h2>
<div class="sectionbody">
<div class="hdlist">
<table>
<tr>
<td class="hdlist1">
<code>NNG_ECLOSED</code>
</td>
<td class="hdlist2">
<p>The socket <em>s</em> does not refer to an open socket.</p>
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_see_also">SEE ALSO</h2>
<div class="sectionbody">
<div class="paragraph text-left">
<p><a href="nng_pipe_close.3.html">nng_pipe_close(3)</a>,
<a href="nng_pipe_getopt.3.html">nng_pipe_getopt(3)</a>,
<a href="nng_pipe.5.html">nng_pipe(5)</a>,
<a href="nng_socket.5.html">nng_socket(5)</a>,
<a href="nng.7.html">nng(7)</a></p>
</div>
</div>
</div>
|
