Stop the referenced
server from accepting any
new requests. The call may block until any “pending”
transactions are completed by the backend-handlers/user-application,
or such pending transactions have been timed-out by the main MODBUS
server control loop. This means the function may block for a maximum
of the active transaction timeout (as specified by the backend
supplied timeout field).
The function will return ENOERR on success. If the
stop event cannot be delivered to the MODBUS control thread due to the
communication mailbox being full, then EAGAIN is
returned. If the
server parameter is invalid
then EINVAL will be returned.