sdi_event(D4I)                                        sdi_event(D4I)


       NAME
             sdi_event - driver event definition structure

       SYNOPSIS
             #include <sys/sdi.h>
             #include <sys/ddi.h>

       DESCRIPTION
             The sdi_event structure defines the parameters of a driver
             event, including the event-handling routine, used in driver-
             to-driver communication.

       USAGE
             This structure is passed to sdi_addevent(D3I) and
             sdi_rmevent(D3I) to register and un-register event handlers.
             The sdi_notifyevent(D3I) routine obtains information about
             which event handlers to call from the list of registered
             sdi_event structures.

             sdi_event structures must be allocated with
             sdi_event_alloc(D3I) and freed with sdi_event_free(D3I).
             Drivers must not allocate them statically or as automatic
             variables.

          Structure Definitions
             The sdi_event structure is defined as type struct sdi_event
             and contains the following members:
             int              event_type;               /* event type code */
             int              (*event_handler)();       /* address of handler routine */
             void             *event_info;              /* event-specific info */
             int              event_pdtype;             /* device type */
             char             event_inquiry[INQ_EXLEN]; /* device inquiry string */
             struct scsi_adr  event_scsi_adr;           /* device's SCSI address */

             The event field indicates the type of driver event being
             manipulated.  The following events are currently defined:
            SDI_FIRSTOPEN       First open of a particular device
            SDI_LASTCLOSE       Last close of a device, with no errors
            SDI_LASTCLOSE_ERR   Last close of a device, with errors

             Note that the sdi_event mechanism as implemented allows
             communicating drivers to define their own private event code
             values outside of this set.  That is, the event codes need
             only be unique to the driver reporting the event and the
             driver handling it.



                           Copyright 1994 Novell, Inc.               Page 1

      sdi_event(D4I)                                        sdi_event(D4I)


            The event_handler field points to the event handler routine.
            This is a function which will be called as follows:
            (*event_handler) (struct sdi_event *event, struct scsi_adr *scsi_adr,
                              struct sb *sbp)

            The event_info field is provided as optional private data for
            the driver handling the event.

            The event_pdtype field holds the SCSI device type of the
            device for which a driver event is being reported.

            The event_inquiry and event_scsi_adr fields specify to which
            devices the event will apply.  A zero-length event_inquiry
            string and -1 values for event_scsi_adr members act as wild
            cards.  Specific values can be provided to narrow the range of
            devices applicable.

      REFERENCES
            sb(D4I), scsi_adr(D4I), sd01(7), sdi_addevent(D3I),
            sdi_event_free(D3I), sdi_event_alloc(D3I),
            sdi_notifyevent(D3I), sdi_rmevent(D3I)

         Future Directions
            The event types SDI_FIRSTOPEN, SDI_LASTCLOSE, and
            SDI_LASTCLOSE_ERR are currently only generated for ID_RANDOM
            type devices (random-access disks) by the sd01 target driver.
            In the future, these events will also be supported for other
            device types.




















                          Copyright 1994 Novell, Inc.               Page 2