Section 3: library functions
zmq_msg_init_data – initialise 0MQ message from a supplied buffer Synopsis typedef void (zmq_free_fn) (void *data, void *hint); int zmq_msg_init_data(zmq_msg_t *msg, void *data, size_t size, zmq_free_fn *ffn, void *hint); Description The zmq_msg_init_data() function shall initialise the message object referenced by msg to represent the content referenced by the buffer located at address data, size bytes long….
zmq_msg_init – initialise empty 0MQ message Synopsis int zmq_msg_init(zmq_msg_t *msg); Description The zmq_msg_init() function shall initialise the message object referenced by msg to represent an empty message. This function is most useful when called before receiving a message with zmq_recv(). Caution Never access zmq_msg_t members directly, instead always use the zmq_msg family of functions. Caution…
zmq_msg_gets – get message metadata property Synopsis const char *zmq_msg_gets(zmq_msg_t *message, const char *property); Description The zmq_msg_gets() function shall return the string value for the metadata property specified by the property argument for the message pointed to by the message argument. Both the property argument and the value shall be NULL-terminated UTF8-encoded strings. Metadata is…
zmq_msg_get – get message property Synopsis int zmq_msg_get(zmq_msg_t *message, int property); Description The zmq_msg_get() function shall return the value for the property specified by the property argument for the message pointed to by the message argument. The following properties can be retrieved with the zmq_msg_get() function: ZMQ_MORE Indicates that there are more message frames to…
zmq_msg_data – retrieve pointer to message content Synopsis void *zmq_msg_data(zmq_msg_t *msg); Description The zmq_msg_data() function shall return a pointer to the message content of the message object referenced by msg. Caution Never access zmq_msg_t members directly, instead always use the zmq_msg family of functions. Return Value Upon successful completion, zmq_msg_data() shall return a pointer to…
zmq_msg_copy – copy content of a message to another message Synopsis int zmq_msg_copy(zmq_msg_t *dest, zmq_msg_t *src); Description The zmq_msg_copy() function shall copy the message object referenced by src to the message object referenced by dest. The original content of dest, if any, shall be released. You must initialize dest before copying to it. Caution The…
zmq_msg_close – release 0MQ message Synopsis int zmq_msg_close(zmq_msg_t *msg); Description The zmq_msg_close() function shall inform the 0MQ infrastructure that any resources associated with the message object referenced by msg are no longer required and may be released. Actual release of resources associated with the message object shall be postponed by 0MQ until all users of…
zmq_has – check a ZMQ capability Synopsis int zmq_has(const char *capability); Description The zmq_has() function shall report whether a specified capability is available in the library. This allows bindings and applications to probe a library directly, for transport and security options. Capabilities shall be lowercase strings. The following capabilities are defined: • ipc – the…
zmq_getsockopt – get 0MQ socket options Synopsis int zmq_getsockopt(void *socket, int option_name, void *option_value, size_t *option_len); Description 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…
zmq_errno – retrieve value of errno for the calling thread Synopsis int zmq_errno(void); Description The zmq_errno() function shall retrieve the value of the errno variable for the calling thread. The zmq_errno() function is provided to assist users on non-POSIX systems who are experiencing issues with retrieving the correct value of errno directly. Specifically, users on…
zmq_disconnect – Disconnect a socket Synopsis int zmq_disconnect(void *socket, const char *endpoint); Description The zmq_disconnect() function shall disconnect a socket specified by the socket argument from the endpoint specified by the endpoint argument. Any outstanding messages physically received from the network but not yet received by the application with zmq_recv() shall be discarded. The behaviour…
zmq_curve_keypair – generate a new CURVE keypair Synopsis int zmq_curve_keypair(char *z85_public_key, char *z85_secret_key); Description The zmq_curve_keypair() function shall return a newly generated random keypair consisting of a public key and a secret key. The caller provides two buffers, each at least 41 octets large, in which this method will store the keys. The keys are…
zmq_ctx_term – destroy a 0MQ context Synopsis int zmq_ctx_term(void *context); Description The zmq_ctx_term() function shall destroy the 0MQ context context. Context termination is performed in the following steps: 1. Any blocking operations currently in progress on sockets open within context shall return immediately with an error code of ETERM. With the exception of zmq_close(), any…
zmq_ctx_shutdown – shutdown a 0MQ context Synopsis int zmq_ctx_shutdown(void *context); Description The zmq_ctx_shutdown() function shall shutdown the 0MQ context context. Context shutdown will cause any blocking operations currently in progress on sockets open within context to return immediately with an error code of ETERM. With the exception of zmq_close(), any further operations on sockets open…
zmq_ctx_set – set context options Synopsis int zmq_ctx_set(void *context, int option_name, int option_value); Description The zmq_ctx_set() function shall set the option specified by the option_name argument to the value of the option_value argument. The zmq_ctx_set() function accepts the following options: ZMQ_IO_THREADS: Set number of I/O threads The ZMQ_IO_THREADS argument specifies the size of the 0MQ…
zmq_ctx_new – create new 0MQ context Synopsis void *zmq_ctx_new(); Description The zmq_ctx_new() function creates a new 0MQ context. This function replaces the deprecated function zmq_init(3). Thread safety. A 0MQ context is thread safe and may be shared among as many application threads as necessary, without any additional locking required on the part of the caller….
zmq_ctx_get – get context options Synopsis int zmq_ctx_get(void *context, int option_name); Description The zmq_ctx_get() function shall return the option specified by the option_name argument. The zmq_ctx_get() function accepts the following option names: ZMQ_IO_THREADS: Get number of I/O threads The ZMQ_IO_THREADS argument returns the size of the 0MQ thread pool for this context. ZMQ_MAX_SOCKETS: Get maximum…
zmq_connect – create outgoing connection from socket Synopsis int zmq_connect(void *socket, const char *endpoint); Description The zmq_connect() function connects the socket to an endpoint and then accepts incoming connections on that endpoint. The endpoint is a string consisting of a transport:// followed by an address. The transport specifies the underlying protocol to use. The address…
zmq_close – close 0MQ socket Synopsis int zmq_close(void *socket); Description 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…
zmq_bind – accept incoming connections on a socket Synopsis int zmq_bind(void *socket, const char *endpoint); Description The zmq_bind() function binds the socket to a local endpoint and then accepts incoming connections on that endpoint. The endpoint is a string consisting of a transport:// followed by an address. The transport specifies the underlying protocol to use….