/** \brief Register for interface events
@param client_index - opaque cookie to identify the sender
@param context - sender context, to match reply w/ request
@param enable_disable - 1 => register for events, 0 => cancel registration
@param pid - sender's pid
*/
/** \brief Register for interface events
@param client_index - opaque cookie to identify the sender
@param context - sender context, to match reply w/ request
@param enable_disable - 1 => register for events, 0 => cancel registration
@param pid - sender's pid
*/