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XS_MSG_INIT_DATA(3)          Crossroads I/O Manual         XS_MSG_INIT_DATA(3)

NAME
       xs_msg_init_data - initialise Crossroads message from a supplied buffer

SYNOPSIS
       typedef void (xs_free_fn) (void *data, void *hint);

       int xs_msg_init_data (xs_msg_t *msg, void *data, size_t size,
       xs_free_fn *ffn, void *hint);

DESCRIPTION
       The xs_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. No copy of data shall be
       performed and the library shall take ownership of the supplied buffer.

       If provided, the deallocation function ffn shall be called once the
       data buffer is no longer required by the library, with the data and
       hint arguments supplied to xs_msg_init_data().

           Caution

           Never access xs_msg_t members directly, instead always use the
           xs_msg family of functions.

           Caution

           The deallocation function ffn needs to be thread-safe, since it
           will be called from an arbitrary thread.

           Caution

           The functions xs_msg_init(), xs_msg_init_data() and
           xs_msg_init_size() are mutually exclusive. Never initialize the
           same xs_msg_t twice.

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

ERRORS
       ENOMEM
           Insufficient storage space is available.

EXAMPLE
       Initialising a message from a supplied buffer.

           void my_free (void *data, void *hint)
           {
               free (data);
           }

               /*  ...  */

           void *data = malloc (6);
           assert (data);
           memcpy (data, "ABCDEF", 6);
           xs_msg_t msg;
           rc = xs_msg_init_data (&msg, data, 6, my_free, NULL);
           assert (rc == 0);

SEE ALSO
       xs_msg_init_size(3) xs_msg_init(3) xs_msg_close(3) xs_msg_data(3)
       xs_msg_size(3) xs(7)

AUTHORS
       The Crossroads documentation was written by Martin Sustrik
       <sustrik@250bpm.com[1]> and Martin Lucina <martin@lucina.net[2]>.

NOTES
        1. sustrik@250bpm.com
           mailto:sustrik@250bpm.com

        2. martin@lucina.net
           mailto:martin@lucina.net

Crossroads I/O 1.2.0              02/17/2016               XS_MSG_INIT_DATA(3)