NAME

       nng_ctx_send - send message using context asynchronously

SYNOPSIS

           #include <nng/nng.h>

           void nng_ctx_send(nng_ctx ctx, nng_aio *aio);

DESCRIPTION

       The nng_ctx_send() sends a message using the context ctx asynchronously.

       The message to send must have previously been set on the aio using the nng_aio_set_msg() function. The
       function assumes ownership of the message.

       If the message was successfully queued for delivery to the socket, then the aio will be completed, and
       nng_aio_result() will return zero. In this case the socket will dispose of the message when it is
       finished with it.

           Note

           The operation will be completed, and the callback associated with the aio executed, as soon as the
           socket accepts the message for sending. This does not indicate that the message was actually
           delivered, as it may still be buffered in the sending socket, buffered in the receiving socket, or in
           flight over physical media.

       If the operation fails for any reason (including cancellation or timeout), then the aio callback will be
       executed and nng_aio_result() will return a non-zero error status. In this case, the callback has a
       responsibility to retrieve the message from the aio with nng_aio_get_msg() and dispose of it
       appropriately. (This may include retrying the send operation on the same or a different socket, or
       deallocating the message with nng_msg_free().)

           Note

           The semantics of what sending a message means varies from protocol to protocol, so examination of the
           protocol documentation is encouraged.

           Tip

           Context send operations are asynchronous. If a synchronous operation is needed, one can be
           constructed by using a NULL callback on the aio and then waiting for the operation using
           nng_aio_wait().

RETURN VALUES

       None. (The operation completes asynchronously.)

ERRORS

       NNG_ECANCELED
           The operation was aborted.

       NNG_ECLOSED
           The context ctx is not open.

       NNG_EMSGSIZE
           The message is too large.

       NNG_ENOMEM
           Insufficient memory is available.

       NNG_ENOTSUP
           The protocol for context ctx does not support sending.

       NNG_ESTATE
           The context ctx cannot send data in this state.

       NNG_ETIMEDOUT
           The send timeout expired.

SEE ALSO

       nng_aio_get_msg(3), nng_aio_set_msg(3), nng_msg_alloc(3), nng_strerror(3), nng_aio(5), nng_ctx(5),
       nng_msg(5), nng(7)

                                                   2025-04-20                                    NNG_CTX_SEND(3)