int zmq_getsockopt (void *socket, int option_name, void *option_value, size_t *option_len);
The zmq_getsockopt() function shall retrieve the value for the option specified by the option_name argument for the 0MQ socket pointed to by the socket argument, and store it in the buffer pointed to by the option_value argument. The option_len argument is the size in bytes of the buffer pointed to by option_value; upon successful completion zmq_getsockopt() shall modify the option_len argument to indicate the actual size of the option value stored in the buffer.
The following options can be retrieved with the zmq_getsockopt() function:
The ZMQ_AFFINITY option shall retrieve the I/O thread affinity for newly created connections on the specified socket.
Affinity determines which threads from the 0MQ I/O thread pool associated with the socket's context shall handle newly created connections. A value of zero specifies no affinity, meaning that work shall be distributed fairly among all 0MQ I/O threads in the thread pool. For non-zero values, the lowest bit corresponds to thread 1, second lowest bit to thread 2 and so on. For example, a value of 3 specifies that subsequent connections on socket shall be handled exclusively by I/O threads 1 and 2.
See also zmq_init(3) for details on allocating the number of I/O threads for a specific context.
|
Option value type |
uint64_t
|
|
Option value unit |
N/A (bitmap)
|
|
Default value |
0
|
|
Applicable socket types |
N/A
|
The ZMQ_BACKLOG option shall retrieve the maximum length of the queue of outstanding peer connections for the specified socket; this only applies to connection-oriented transports. For details refer to your operating system documentation for the listen function.
|
Option value type |
int
|
|
Option value unit |
connections
|
|
Default value |
100
|
|
Applicable socket types |
all, only for connection-oriented transports
|
The ZMQ_BINDTODEVICE option retrieves the name of the device this socket is bound to, eg. an interface or VRF. If a socket is bound to an interface, only packets received from that interface are processed by the socket. If device is a VRF device, then subsequent binds/connects to that socket use addresses in the VRF routing table.
|
Option value type |
character string
|
|
Option value unit |
N/A
|
|
Default value |
not set
|
|
Applicable socket types |
all, when using TCP or UDP transports.
|
Retrieves how long to wait before timing-out a connect() system call. The connect() system call normally takes a long time before it returns a time out error. Setting this option allows the library to time out the call at an earlier interval.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
0 (disabled)
|
|
Applicable socket types |
all, when using TCP transports.
|
Retrieves the current long term public key for the socket. You can provide either a 32 byte buffer, to retrieve the binary key value, or a 41 byte buffer, to retrieve the key in a printable Z85 format. NOTE: to fetch a printable key, the buffer must be 41 bytes large to hold the 40-char key value and one null byte.
|
Option value type |
binary data or Z85 text string
|
|
Option value size |
32 or 41
|
|
Default value |
null
|
|
Applicable socket types |
all, when using TCP transport
|
Retrieves the current long term secret key for the socket. You can provide either a 32 byte buffer, to retrieve the binary key value, or a 41 byte buffer, to retrieve the key in a printable Z85 format. NOTE: to fetch a printable key, the buffer must be 41 bytes large to hold the 40-char key value and one null byte.
|
Option value type |
binary data or Z85 text string
|
|
Option value size |
32 or 41
|
|
Default value |
null
|
|
Applicable socket types |
all, when using TCP transport
|
Retrieves the current server key for the client socket. You can provide either a 32 byte buffer, to retrieve the binary key value, or a 41-byte buffer, to retrieve the key in a printable Z85 format. NOTE: to fetch a printable key, the buffer must be 41 bytes large to hold the 40-char key value and one null byte.
|
Option value type |
binary data or Z85 text string
|
|
Option value size |
32 or 41
|
|
Default value |
null
|
|
Applicable socket types |
all, when using TCP transport
|
The ZMQ_EVENTS option shall retrieve the event state for the specified socket. The returned value is a bit mask constructed by OR'ing a combination of the following event flags:
ZMQ_POLLIN
ZMQ_POLLOUT
The combination of a file descriptor returned by the ZMQ_FD option being ready for reading but no actual events returned by a subsequent retrieval of the ZMQ_EVENTS option is valid; applications should simply ignore this case and restart their polling operation/event loop.
|
Option value type |
int
|
|
Option value unit |
N/A (flags)
|
|
Default value |
N/A
|
|
Applicable socket types |
all
|
The ZMQ_FD option shall retrieve the file descriptor associated with the specified socket. The returned file descriptor can be used to integrate the socket into an existing event loop; the 0MQ library shall signal any pending events on the socket in an edge-triggered fashion by making the file descriptor become ready for reading.
The ability to read from the returned file descriptor does not necessarily indicate that messages are available to be read from, or can be written to, the underlying socket; applications must retrieve the actual event state with a subsequent retrieval of the ZMQ_EVENTS option.
The returned file descriptor is also used internally by the zmq_send and zmq_recv functions. As the descriptor is edge triggered, applications must update the state of ZMQ_EVENTS after each invocation of zmq_send or zmq_recv.To be more explicit: after calling zmq_send the socket may become readable (and vice versa) without triggering a read event on the file descriptor.
The returned file descriptor is intended for use with a poll or similar system call only. Applications must never attempt to read or write data to it directly, neither should they try to close it.
|
Option value type |
int on POSIX systems, SOCKET on Windows
|
|
Option value unit |
N/A
|
|
Default value |
N/A
|
|
Applicable socket types |
all
|
Returns the ZMQ_GSSAPI_PLAINTEXT option, if any, previously set on the socket. A value of 1 means that communications will be plaintext. A value of 0 means communications will be encrypted.
|
Option value type |
int
|
|
Option value unit |
0, 1
|
|
Default value |
0 (false)
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
The ZMQ_GSSAPI_PRINCIPAL option shall retrieve the principal name set for the GSSAPI security mechanism. The returned value shall be a NULL-terminated string and MAY be empty. The returned size SHALL include the terminating null byte.
|
Option value type |
NULL-terminated character string
|
|
Option value unit |
N/A
|
|
Default value |
null string
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
Returns the ZMQ_GSSAPI_SERVER option, if any, previously set on the socket.
|
Option value type |
int
|
|
Option value unit |
0, 1
|
|
Default value |
0 (false)
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
The ZMQ_GSSAPI_SERVICE_PRINCIPAL option shall retrieve the principal name of the GSSAPI server to which a GSSAPI client socket intends to connect. The returned value shall be a NULL-terminated string and MAY be empty. The returned size SHALL include the terminating null byte.
|
Option value type |
NULL-terminated character string
|
|
Option value unit |
N/A
|
|
Default value |
null string
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
Returns the ZMQ_GSSAPI_SERVICE_PRINCIPAL_NAMETYPE option, if any, previously set on the socket. A value of ZMQ_GSSAPI_NT_HOSTBASED (0) means the name specified with ZMQ_GSSAPI_SERVICE_PRINCIPAL is interpreted as a host based name. A value of ZMQ_GSSAPI_NT_USER_NAME (1) means it is interpreted as a local user name. A value of ZMQ_GSSAPI_NT_KRB5_PRINCIPAL (2) means it is interpreted as an unparsed principal name string (valid only with the krb5 GSSAPI mechanism).
|
Option value type |
int
|
|
Option value unit |
0, 1, 2
|
|
Default value |
0 (ZMQ_GSSAPI_NT_HOSTBASED)
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
Returns the ZMQ_GSSAPI_PRINCIPAL_NAMETYPE option, if any, previously set on the socket. A value of ZMQ_GSSAPI_NT_HOSTBASED (0) means the name specified with ZMQ_GSSAPI_PRINCIPAL is interpreted as a host based name. A value of ZMQ_GSSAPI_NT_USER_NAME (1) means it is interpreted as a local user name. A value of ZMQ_GSSAPI_NT_KRB5_PRINCIPAL (2) means it is interpreted as an unparsed principal name string (valid only with the krb5 GSSAPI mechanism).
|
Option value type |
int
|
|
Option value unit |
0, 1, 2
|
|
Default value |
0 (ZMQ_GSSAPI_NT_HOSTBASED)
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
The ZMQ_HANDSHAKE_IVL option shall retrieve the maximum handshake interval for the specified socket. Handshaking is the exchange of socket configuration information (socket type, routing id, security) that occurs when a connection is first opened, only for connection-oriented transports. If handshaking does not complete within the configured time, the connection shall be closed. The value 0 means no handshake time limit.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
30000
|
|
Applicable socket types |
all but ZMQ_STREAM, only for connection-oriented transports
|
This option name is now deprecated. Use ZMQ_ROUTING_ID instead. ZMQ_IDENTITY remains as an alias for now.
Retrieve the state of the attach on connect value. If set to 1, will delay the attachment of a pipe on connect until the underlying connection has completed. This will cause the socket to block if there are no other connections, but will prevent queues from filling on pipes awaiting connection.
|
Option value type |
int
|
|
Option value unit |
boolean
|
|
Default value |
0 (false)
|
|
Applicable socket types |
all, primarily when using TCP/IPC transports.
|
Returns the value of the ZMQ_INVERT_MATCHING option. A value of 1 means the socket uses inverted prefix matching.
On PUB and XPUB sockets, this causes messages to be sent to all connected sockets except those subscribed to a prefix that matches the message. On SUB sockets, this causes only incoming messages that do not match any of the socket's subscriptions to be received by the user.
Whenever ZMQ_INVERT_MATCHING is set to 1 on a PUB socket, all SUB sockets connecting to it must also have the option set to 1. Failure to do so will have the SUB sockets reject everything the PUB socket sends them. XSUB sockets do not need to do this because they do not filter incoming messages.
|
Option value type |
int
|
|
Option value unit |
0,1
|
|
Default value |
0
|
|
Applicable socket types |
ZMQ_PUB, ZMQ_XPUB, ZMQ_SUB
|
Retrieve the IPv4-only option for the socket. This option is deprecated. Please use the ZMQ_IPV6 option.
|
Option value type |
int
|
|
Option value unit |
boolean
|
|
Default value |
1 (true)
|
|
Applicable socket types |
all, when using TCP transports.
|
Retrieve the IPv6 option for the socket. A value of 1 means IPv6 is enabled on the socket, while 0 means the socket will use only IPv4. When IPv6 is enabled the socket will connect to, or accept connections from, both IPv4 and IPv6 hosts.
|
Option value type |
int
|
|
Option value unit |
boolean
|
|
Default value |
0 (false)
|
|
Applicable socket types |
all, when using TCP transports.
|
The ZMQ_LAST_ENDPOINT option shall retrieve the last endpoint bound for TCP and IPC transports. The returned value will be a string in the form of a ZMQ DSN. Note that if the TCP host is INADDR_ANY, indicated by a *, then the returned address will be 0.0.0.0 (for IPv4). Note: not supported on GNU/Hurd with IPC due to non-working getsockname().
|
Option value type |
NULL-terminated character string
|
|
Option value unit |
N/A
|
|
Default value |
NULL
|
|
Applicable socket types |
all, when binding TCP or IPC transports
|
The ZMQ_LINGER option shall retrieve the linger period for the specified socket. The linger period determines how long pending messages which have yet to be sent to a peer shall linger in memory after a socket is closed with zmq_close(3), and further affects the termination of the socket's context with zmq_ctx_term(3). The following outlines the different behaviours:
| Option value type |
int
|
| Option value unit |
milliseconds
|
| Default value |
-1 (infinite)
|
| Applicable socket types |
all
|
The option shall retrieve limit for the inbound messages. If a peer sends a message larger than ZMQ_MAXMSGSIZE it is disconnected. Value of -1 means no limit.
|
Option value type |
int64_t
|
|
Option value unit |
bytes
|
|
Default value |
-1
|
|
Applicable socket types |
all
|
The ZMQ_MECHANISM option shall retrieve the current security mechanism for the socket.
|
Option value type |
int
|
|
Option value unit |
ZMQ_NULL, ZMQ_PLAIN, ZMQ_CURVE, or ZMQ_GSSAPI
|
|
Default value |
ZMQ_NULL
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
The option shall retrieve time-to-live used for outbound multicast packets. The default of 1 means that the multicast packets don't leave the local network.
|
Option value type |
int
|
|
Option value unit |
network hops
|
|
Default value |
1
|
|
Applicable socket types |
all, when using multicast transports
|
The ZMQ_MULTICAST_MAXTPDU option shall retrieve the maximum transport data unit size used for outbound multicast packets.
This must be set at or below the minimum Maximum Transmission Unit (MTU) for all network paths over which multicast reception is required.
|
Option value type |
int
|
|
Option value unit |
bytes
|
|
Default value |
1500
|
|
Applicable socket types |
all, when using multicast transports
|
The ZMQ_PLAIN_PASSWORD option shall retrieve the last password set for the PLAIN security mechanism. The returned value shall be a NULL-terminated string and MAY be empty. The returned size SHALL include the terminating null byte.
|
Option value type |
NULL-terminated character string
|
|
Option value unit |
N/A
|
|
Default value |
null string
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
Returns the ZMQ_PLAIN_SERVER option, if any, previously set on the socket.
|
Option value type |
int
|
|
Option value unit |
0, 1
|
|
Default value |
int
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
The ZMQ_PLAIN_USERNAME option shall retrieve the last username set for the PLAIN security mechanism. The returned value shall be a NULL-terminated string and MAY be empty. The returned size SHALL include the terminating null byte.
|
Option value type |
NULL-terminated character string
|
|
Option value unit |
N/A
|
|
Default value |
null string
|
|
Applicable socket types |
all, when using TCP or IPC transports
|
The ZMQ_USE_FD option shall retrieve the pre-allocated file descriptor that has been assigned to a ZMQ socket, if any. -1 shall be returned if a pre-allocated file descriptor was not set for the socket.
|
Option value type |
int
|
|
Option value unit |
file descriptor
|
|
Default value |
-1
|
|
Applicable socket types |
all bound sockets, when using IPC or TCP transport
|
ZMQ_PRIORITY: Retrieve the Priority on socket
Gets the protocol-defined priority for all packets to be sent on this socket, where supported by the OS. [horizontal] Option value type:: int Option value unit:: >0 Default value:: 0 Applicable socket types:: all, only for connection-oriented transports ZMQ_RATE: Retrieve multicast data rate
The ZMQ_RATE option shall retrieve the maximum send or receive data rate for multicast transports using the specified socket.
|
Option value type |
int
|
|
Option value unit |
kilobits per second
|
|
Default value |
100
|
|
Applicable socket types |
all, when using multicast transports
|
The ZMQ_RCVBUF option shall retrieve the underlying kernel receive buffer size for the specified socket. For details refer to your operating system documentation for the SO_RCVBUF socket option.
|
Option value type |
int
|
|
Option value unit |
bytes
|
|
Default value |
8192
|
|
Applicable socket types |
all
|
The ZMQ_RCVHWM option shall return the high water mark for inbound messages on the specified socket. The high water mark is a hard limit on the maximum number of outstanding messages 0MQ shall queue in memory for any single peer that the specified socket is communicating with. A value of zero means no limit.
If this limit has been reached the socket shall enter an exceptional state and depending on the socket type, 0MQ shall take appropriate action such as blocking or dropping sent messages. Refer to the individual socket descriptions in zmq_socket(3) for details on the exact action taken for each socket type.
|
Option value type |
int
|
|
Option value unit |
messages
|
|
Default value |
1000
|
|
Applicable socket types |
all
|
The ZMQ_RCVMORE option shall return True (1) if the message part last received from the socket was a data part with more parts to follow. If there are no data parts to follow, this option shall return False (0).
Refer to zmq_send(3) and zmq_recv(3) for a detailed description of multi-part messages.
|
Option value type |
int
|
|
Option value unit |
boolean
|
|
Default value |
N/A
|
|
Applicable socket types |
all
|
Retrieve the timeout for recv operation on the socket. If the value is 0, zmq_recv(3) will return immediately, with a EAGAIN error if there is no message to receive. If the value is -1, it will block until a message is available. For all other values, it will wait for a message for that amount of time before returning with an EAGAIN error.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
-1 (infinite)
|
|
Applicable socket types |
all
|
The ZMQ_RECONNECT_IVL option shall retrieve the initial reconnection interval for the specified socket. The reconnection interval is the period 0MQ shall wait between attempts to reconnect disconnected peers when using connection-oriented transports. The value -1 means no reconnection.
The reconnection interval may be randomized by 0MQ to prevent reconnection storms in topologies with a large number of peers per socket.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
100
|
|
Applicable socket types |
all, only for connection-oriented transports
|
The ZMQ_RECONNECT_IVL_MAX option shall retrieve the maximum reconnection interval for the specified socket. This is the maximum period 0MQ shall wait between attempts to reconnect. On each reconnect attempt, the previous interval shall be doubled untill ZMQ_RECONNECT_IVL_MAX is reached. This allows for exponential backoff strategy. Default value means no exponential backoff is performed and reconnect interval calculations are only based on ZMQ_RECONNECT_IVL.
Values less than ZMQ_RECONNECT_IVL will be ignored.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
0 (only use ZMQ_RECONNECT_IVL)
|
|
Applicable socket types |
all, only for connection-oriented transport
|
The ZMQ_RECONNECT_STOP option shall retrieve the conditions under which automatic reconnection will stop.
The ZMQ_RECONNECT_STOP_CONN_REFUSED option will stop reconnection when 0MQ receives the ECONNREFUSED return code from the connect. This indicates that there is no code bound to the specified endpoint.
|
Option value type |
int
|
|
Option value unit |
ZMQ_RECONNECT_STOP_CONN_REFUSED
|
|
Default value |
0
|
|
Applicable socket types |
all, only for connection-oriented transports
|
The ZMQ_RECOVERY_IVL option shall retrieve the recovery interval for multicast transports using the specified socket. The recovery interval determines the maximum time in milliseconds that a receiver can be absent from a multicast group before unrecoverable data loss will occur.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
10000
|
|
Applicable socket types |
all, when using multicast transports
|
The ZMQ_ROUTING_ID option shall retrieve the routing id of the specified socket. Routing ids are used only by the request/reply pattern. Specifically, it can be used in tandem with ROUTER socket to route messages to the peer with a specific routing id.
A routing id must be at least one byte and at most 255 bytes long. Identities starting with a zero byte are reserved for use by the 0MQ infrastructure.
|
Option value type |
binary data
|
|
Option value unit |
N/A
|
|
Default value |
NULL
|
|
Applicable socket types |
ZMQ_REP, ZMQ_REQ, ZMQ_ROUTER, ZMQ_DEALER.
|
The ZMQ_SNDBUF option shall retrieve the underlying kernel transmit buffer size for the specified socket. For details refer to your operating system documentation for the SO_SNDBUF socket option.
|
Option value type |
int
|
|
Option value unit |
bytes
|
|
Default value |
8192
|
|
Applicable socket types |
all
|
The ZMQ_SNDHWM option shall return the high water mark for outbound messages on the specified socket. The high water mark is a hard limit on the maximum number of outstanding messages 0MQ shall queue in memory for any single peer that the specified socket is communicating with. A value of zero means no limit.
If this limit has been reached the socket shall enter an exceptional state and depending on the socket type, 0MQ shall take appropriate action such as blocking or dropping sent messages. Refer to the individual socket descriptions in zmq_socket(3) for details on the exact action taken for each socket type.
|
Option value type |
int
|
|
Option value unit |
messages
|
|
Default value |
1000
|
|
Applicable socket types |
all
|
Retrieve the timeout for send operation on the socket. If the value is 0, zmq_send(3) will return immediately, with a EAGAIN error if the message cannot be sent. If the value is -1, it will block until the message is sent. For all other values, it will try to send the message for that amount of time before returning with an EAGAIN error.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
-1 (infinite)
|
|
Applicable socket types |
all
|
The ZMQ_SOCKS_PROXY option shall retrieve the SOCKS5 proxy address in string format. The returned value shall be a NULL-terminated string and MAY be empty. The returned size SHALL include the terminating null byte.
|
Option value type |
NULL-terminated character string
|
|
Option value unit |
N/A
|
|
Default value |
null string
|
|
Applicable socket types |
all, when using TCP transports
|
Override SO_KEEPALIVE socket option(where supported by OS). The default value of -1 means to skip any overrides and leave it to OS default.
|
Option value type |
int
|
|
Option value unit |
-1,0,1
|
|
Default value |
-1 (leave to OS default)
|
|
Applicable socket types |
all, when using TCP transports.
|
Override TCP_KEEPCNT socket option(where supported by OS). The default value of -1 means to skip any overrides and leave it to OS default.
|
Option value type |
int
|
|
Option value unit |
-1,>0
|
|
Default value |
-1 (leave to OS default)
|
|
Applicable socket types |
all, when using TCP transports.
|
Override TCP_KEEPIDLE(or TCP_KEEPALIVE on some OS) socket option (where supported by OS). The default value of -1 means to skip any overrides and leave it to OS default.
|
Option value type |
int
|
|
Option value unit |
-1,>0
|
|
Default value |
-1 (leave to OS default)
|
|
Applicable socket types |
all, when using TCP transports.
|
Override TCP_KEEPINTVL socket option(where supported by OS). The default value of -1 means to skip any overrides and leave it to OS default.
|
Option value type |
int
|
|
Option value unit |
-1,>0
|
|
Default value |
-1 (leave to OS default)
|
|
Applicable socket types |
all, when using TCP transports.
|
On OSes where it is supported, retrieves how long before an unacknowledged TCP retransmit times out. The system normally attempts many TCP retransmits following an exponential backoff strategy. This means that after a network outage, it may take a long time before the session can be re-established. Setting this option allows the timeout to happen at a shorter interval.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
0 (leave to OS default)
|
|
Applicable socket types |
all, when using TCP transports.
|
The ZMQ_THREAD_SAFE option shall retrieve a boolean value indicating whether or not the socket is threadsafe. See zmq_socket(3) for which sockets are thread-safe.
|
Option value type |
int
|
|
Option value unit |
boolean
|
|
Applicable socket types |
all
|
Retrieve the IP_TOS option for the socket.
|
Option value type |
int
|
|
Option value unit |
>0
|
|
Default value |
0
|
|
Applicable socket types |
all, only for connection-oriented transports
|
The ZMQ_TYPE option shall retrieve the socket type for the specified socket. The socket type is specified at socket creation time and cannot be modified afterwards.
|
Option value type |
int
|
|
Option value unit |
N/A
|
|
Default value |
N/A
|
|
Applicable socket types |
all
|
The ZMQ_ZAP_DOMAIN option shall retrieve the last ZAP domain set for the socket. The returned value shall be a NULL-terminated string and MAY be empty. An empty string means that ZAP authentication is disabled. The returned size SHALL include the terminating null byte.
|
Option value type |
character string
|
|
Option value unit |
N/A
|
|
Default value |
not set
|
|
Applicable socket types |
all, when using TCP transport
|
The ZMQ_ZAP_ENFORCE_DOMAIN option shall retrieve the flag that determines whether a ZAP domain is strictly required or not.
|
Option value type |
int
|
|
Option value unit |
0, 1
|
|
Default value |
0
|
|
Applicable socket types |
all, when using ZAP
|
The ZMQ_VMCI_BUFFER_SIZE option shall retrieve the size of the underlying buffer for the socket. Used during negotiation before the connection is established.
|
Option value type |
uint64_t
|
|
Option value unit |
bytes
|
|
Default value |
65546
|
|
Applicable socket types |
all, when using VMCI transport
|
The ZMQ_VMCI_BUFFER_MIN_SIZE option shall retrieve the min size of the underlying buffer for the socket. Used during negotiation before the connection is established.
|
Option value type |
uint64_t
|
|
Option value unit |
bytes
|
|
Default value |
128
|
|
Applicable socket types |
all, when using VMCI transport
|
The ZMQ_VMCI_BUFFER_MAX_SIZE option shall retrieve the max size of the underlying buffer for the socket. Used during negotiation before the connection is established.
|
Option value type |
uint64_t
|
|
Option value unit |
bytes
|
|
Default value |
262144
|
|
Applicable socket types |
all, when using VMCI transport
|
The ZMQ_VMCI_CONNECT_TIMEOUT option shall retrieve connection timeout for the socket.
|
Option value type |
int
|
|
Option value unit |
milliseconds
|
|
Default value |
-1
|
|
Applicable socket types |
all, when using VMCI transport
|
Retrieve the current multicast loopback configuration. A value of 1 means that the multicast packets sent on this socket will be looped back to local listening interface.
|
Option value type |
int
|
|
Option value unit |
0, 1
|
|
Default value |
1
|
|
Applicable socket types |
ZMQ_RADIO, when using UDP multicast transport
|
Retrieve the current notification settings of a router socket. The returned value is a bitmask composed of ZMQ_NOTIFY_CONNECT and ZMQ_NOTIFY_DISCONNECT flags, meaning connect and disconnect notifications are enabled, respectively. A value of 0 means the notifications are off.
in DRAFT state, not yet available in stable releases.
|
Option value type |
int
|
|
Option value unit |
0, ZMQ_NOTIFY_CONNECT, ZMQ_NOTIFY_DISCONNECT, ZMQ_NOTIFY_CONNECT | ZMQ_NOTIFY_DISCONNECT
|
|
Default value |
0
|
|
Applicable socket types |
ZMQ_ROUTER
|
Gets the maximal amount of messages that can be received in a single recv system call.
Cannot be zero.
in DRAFT state, not yet available in stable releases.
|
Option value type |
int
|
|
Option value unit |
messages
|
|
Default value |
8192
|
|
Applicable socket types |
All, when using TCP, IPC, PGM or NORM transport.
|
Gets the maximal amount of messages that can be sent in a single send system call.
Cannot be zero.
in DRAFT state, not yet available in stable releases.
|
Option value type |
int
|
|
Option value unit |
messages
|
|
Default value |
8192
|
|
Applicable socket types |
All, when using TCP, IPC, PGM or NORM transport.
|
The zmq_getsockopt() function shall return zero if successful. Otherwise it shall return -1 and set errno to one of the values defined below.
EINVAL
ETERM
ENOTSOCK
EINTR
Retrieving the high water mark for outgoing messages.
/* Retrieve high water mark into sndhwm */ int sndhwm; size_t sndhwm_size = sizeof (sndhwm); rc = zmq_getsockopt (socket, ZMQ_SNDHWM, &sndhwm, &sndhwm_size); assert (rc == 0);
zmq_setsockopt(3) zmq_socket(3) zmq(7)
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