bionic (3) zmq_ctx_get.3.gz

NAME

       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 number of sockets
       The ZMQ_MAX_SOCKETS argument returns the maximum number of sockets allowed for this context.

   ZMQ_MAX_MSGSZ: Get maximum message size
       The ZMQ_MAX_MSGSZ argument returns the maximum size of a message allowed for this context. Default value
       is INT_MAX.

   ZMQ_ZERO_COPY_RCV: Get message decoding strategy
       The ZMQ_ZERO_COPY_RCV argument return whether message decoder uses a zero copy strategy when receiving
       messages. Default value is 1. NOTE: in DRAFT state, not yet available in stable releases.

   ZMQ_SOCKET_LIMIT: Get largest configurable number of sockets
       The ZMQ_SOCKET_LIMIT argument returns the largest number of sockets that zmq_ctx_set(3) will accept.

   ZMQ_IPV6: Set IPv6 option
       The ZMQ_IPV6 argument returns the IPv6 option for the context.

   ZMQ_BLOCKY: Get blocky setting
       The ZMQ_BLOCKY argument returns 1 if the context will block on terminate, zero if the "block forever on
       context termination" gambit was disabled by setting ZMQ_BLOCKY to false on all new contexts.

   ZMQ_MSG_T_SIZE: Get the zmq_msg_t size at runtime
       The ZMQ_MSG_T_SIZE argument returns the size of the zmq_msg_t structure at runtime, as defined in the
       include/zmq.h public header. This is useful for example for FFI bindings that can’t simply do a sizeof().
       NOTE: in DRAFT state, not yet available in stable releases.

RETURN VALUE

       The zmq_ctx_get() function returns a value of 0 or greater if successful. Otherwise it returns -1 and
       sets errno to one of the values defined below.

ERRORS

       EINVAL
           The requested option option_name is unknown.

EXAMPLE

       Setting a limit on the number of sockets.

           void *context = zmq_ctx_new ();
           zmq_ctx_set (context, ZMQ_MAX_SOCKETS, 256);
           int max_sockets = zmq_ctx_get (context, ZMQ_MAX_SOCKETS);
           assert (max_sockets == 256);

       Switching off the context deadlock gambit.

           zmq_ctx_set (ctx, ZMQ_BLOCKY, false);

SEE ALSO

       zmq_ctx_set(3) zmq(7)

AUTHORS

       This page was written by the 0MQ community. To make a change please read the 0MQ Contribution Policy at
       http://www.zeromq.org/docs:contributing.