ØMQ Manual - ØMQ/4.3.1


zmq_close - close ØMQ socket


int zmq_close (void *socket);


The zmq_close() function shall destroy the socket referenced by the socket argument. Any outstanding messages physically received from the network but not yet received by the application with zmq_recv() shall be discarded. The behaviour for discarding messages sent by the application with zmq_send() but not yet physically transferred to the network depends on the value of the ZMQ_LINGER socket option for the specified socket.

zmq_close() must be called exactly once for each socket. If it is never called, zmq_ctx_term() will block forever. If it is called multiple times for the same socket or if socket does not point to a socket, the behaviour is undefined.

The default setting of ZMQ_LINGER does not discard unsent messages; this behaviour may cause the application to block when calling zmq_ctx_term(). For details refer to zmq_setsockopt(3) and zmq_ctx_term(3).

This API will complete asynchronously, so not everything will be deallocated after it returns. See above for details about linger.

Return value

The zmq_close() function shall return zero if successful. Otherwise it shall return -1 and set errno to one of the values defined below.


The provided socket was NULL.

See also

zmq_socket(3) zmq_ctx_term(3) zmq_setsockopt(3) zmq(7)


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