1NN_SETSOCKOPT(3) nanomsg 1.1.5 NN_SETSOCKOPT(3)
2
6 nn_setsockopt - set a socket option
7
9 #include <nanomsg/nn.h>
10 int nn_setsockopt (int s, int level, int option, const void *optval,
12 size_t optvallen);
13
15 Sets the value of the option. The level argument specifies the protocol
16 level at which the option resides. For generic socket-level options use
17 NN_SOL_SOCKET level. For socket-type-specific options use socket type
18 for level argument (e.g. NN_SUB). For transport-specific options use ID
19 of the transport as the level argument (e.g. NN_TCP).
20 The new value is pointed to by optval argument. Size of the option is
22 specified by the optvallen argument.
23 <nanomsg/nn.h> header defines generic socket-level options
25 (NN_SOL_SOCKET level). The options are as follows:
26 NN_SNDBUF
28 Size of the send buffer, in bytes. To prevent blocking for messages
29 larger than the buffer, exactly one message may be buffered in
30 addition to the data in the send buffer. The type of this option is
31 int. Default value is 128kB.
32 NN_RCVBUF
34 Size of the receive buffer, in bytes. To prevent blocking for
35 messages larger than the buffer, exactly one message may be
36 buffered in addition to the data in the receive buffer. The type of
37 this option is int. Default value is 128kB.
38 NN_RCVMAXSIZE
40 Maximum message size that can be received, in bytes. Negative value
41 means that the received size is limited only by available
42 addressable memory. The type of this option is int. Default is
43 1024kB.
44 NN_SNDTIMEO
46 The timeout for send operation on the socket, in milliseconds. If
47 message cannot be sent within the specified timeout, ETIMEDOUT
48 error is returned. Negative value means infinite timeout. The type
49 of the option is int. Default value is -1.
50 NN_RCVTIMEO
52 The timeout for recv operation on the socket, in milliseconds. If
53 message cannot be received within the specified timeout, ETIMEDOUT
54 error is returned. Negative value means infinite timeout. The type
55 of the option is int. Default value is -1.
56 NN_RECONNECT_IVL
58 For connection-based transports such as TCP, this option specifies
59 how long to wait, in milliseconds, when connection is broken before
60 trying to re-establish it. Note that actual reconnect interval may
61 be randomised to some extent to prevent severe reconnection storms.
62 The type of the option is int. Default value is 100 (0.1 second).
63 NN_RECONNECT_IVL_MAX
65 This option is to be used only in addition to NN_RECONNECT_IVL
66 option. It specifies maximum reconnection interval. On each
67 reconnect attempt, the previous interval is doubled until
68 NN_RECONNECT_IVL_MAX is reached. Value of zero means that no
69 exponential backoff is performed and reconnect interval is based
70 only on NN_RECONNECT_IVL. If NN_RECONNECT_IVL_MAX is less than
71 NN_RECONNECT_IVL, it is ignored. The type of the option is int.
72 Default value is 0.
73 NN_SNDPRIO
75 Sets outbound priority for endpoints subsequently added to the
76 socket. This option has no effect on socket types that send
77 messages to all the peers. However, if the socket type sends each
78 message to a single peer (or a limited set of peers), peers with
79 high priority take precedence over peers with low priority. The
80 type of the option is int. Highest priority is 1, lowest priority
81 is 16. Default value is 8.
82 NN_RCVPRIO
84 Sets inbound priority for endpoints subsequently added to the
85 socket. This option has no effect on socket types that are not able
86 to receive messages. When receiving a message, messages from peer
87 with higher priority are received before messages from peer with
88 lower priority. The type of the option is int. Highest priority is
89 1, lowest priority is 16. Default value is 8.
90 NN_IPV4ONLY
92 If set to 1, only IPv4 addresses are used. If set to 0, both IPv4
93 and IPv6 addresses are used. The type of the option is int. Default
94 value is 1.
95 NN_SOCKET_NAME
97 Socket name for error reporting and statistics. The type of the
98 option is string. Default value is "socket.N" where N is socket
99 integer. This option is experimental, see nn_env(7) for details
100 NN_MAXTTL
102 Sets the maximum number of "hops" a message can go through before
103 it is dropped. Each time the message is received (for example via
104 the nn_device(3) function) counts as a single hop. This provides a
105 form of protection against inadvertent loops.
106 NN_LINGER
108 This option is not implemented, and should not be used in new code.
109 Applications which need to be sure that their messages are
110 delivered to a remote peer should either use an acknowledgement
111 (implied when receiving a reply on NN_REQ sockets), or insert a
112 suitable delay before calling nn_close(3) or exiting the
113 application.
114
116 If the function succeeds zero is returned. Otherwise, -1 is returned
117 and errno is set to to one of the values defined below.
118
120 EBADF
121 The provided socket is invalid.
122 ENOPROTOOPT
124 The option is unknown at the level indicated.
125 EINVAL
127 The specified option value is invalid.
128 ETERM
130 The library is terminating.
131
133 int linger = 1000;
134 nn_setsockopt (s, NN_SOL_SOCKET, NN_LINGER, &linger, sizeof (linger));
135 nn_setsockopt (s, NN_SUB, NN_SUB_SUBSCRIBE, "ABC", 3);
136
138 nn_socket(3) nn_getsockopt(3) nanomsg(7)
139
141 Martin Sustrik <sustrik@250bpm.com> Garrett D’Amore
142 <garrett@damore.org>
143 2021-01-26 NN_SETSOCKOPT(3)