Kernel Functions for Drivers                         ldipoll(9F)



NAME
     ldipoll - Poll a device

SYNOPSIS
     #include 



     int ldipoll(ldihandlet lh, short events, int anyyet, short *reventsp,
          struct pollhead **phpp);


PARAMETERS
     lh           Layered handle.


     events       Potential events. Valid events are:

                  POLIN        Data  other  than  high  priority
                                data  may  be read without block-
                                ing.


                  POLOUT       Normal  data   may   be   written
                                without blocking.


                  POLPRI       High   priority   data   may   be
                                received without blocking.


                  POLHUP       Device hangup has occurred.


                  POLER       An error has occurred on the dev-
                                ice.


                  POLRDNORM    Normal data (priority band  =  0)
                                may be read without blocking.


                  POLRDBAND    Data  from  a  non-zero  priority
                                band  may  be read without block-
                                ing.


                  POLWRNORM    Data  other  than  high  priority
                                data  may  be read without block-
                                ing.





SunOS 5.11          Last change: 3 June 2003                    1






Kernel Functions for Drivers                         ldipoll(9F)



                  POLWRBAND    Priority data (priority band > 0)
                                may be written.



     anyyet       A flag that  is  non-zero  if  any  other  file
                  descriptors                 in the pollfd array
                  have events pending. The  poll(2)  system  call
                  takes   a   pointer   to  an  array  of  pollfd
                  structures as one of its arguments. See poll(2)
                  for more details.


     reventsp     Pointer to a bitmask  of  the  returned  events
                  satisfied.


     phpp         Pointer to a pointer to a pollhead structure.


DESCRIPTION
     The ldipoll() function passes a poll request to the  device
     entry  point for the device specified by the layered handle.
     This  operation  is  supported  for  block,  character,  and
     streams devices.

RETURN VALUES
     The ldipoll() function returns 0 upon success. If a failure
     occurs before the request is passed on to the device, possi-
     ble return values are:

     EINVAL     Invalid input parameters.


     ENOTSUP    Operation is not supported for this device.


CONTEXT
     These functions may be called from user or kernel context.
















SunOS 5.11          Last change: 3 June 2003                    2