Data Structures for Drivers                          kstatio(9S)



NAME
     kstatio - structure for I/O kstats

SYNOPSIS
     #include 
     #include 
     #include 
     #include 


INTERFACE LEVEL
     Solaris DI specific (Solaris DI)

DESCRIPTION
     I/O kstat statistics are kept in a kstatio structure.  When
     kstatcreate(9F)  creates an I/O kstat, the ksdata field is
     a  pointer  to  one   of   these   structures.   The   macro
     KSTATIOPTR()  is provided to retrieve this field. It looks
     like this:

       #define KSTATIOPTR(kptr)    ((kstatiot *)(kptr)->ksdata)


STRUCTURE MEMBERS
       ulonglongt      nread;      /* number of bytes read */
       ulonglongt      nwritten;   /* number of bytes written *]/
       ulongt           reads;      /* number of read operations */
       ulongt           writes;     /* number of write operations */



     The nread field should be updated by  the  driver  with  the
     number of bytes successfully read upon completion.


     The nwritten field should be updated by the driver with  the
     number of bytes successfully written upon completion.


     The reads field should be updated by the driver  after  each
     successful read operation.


     The writes field should be updated by the driver after  each
     successful write operation.


     Other I/O statistics are updated  through  the  use  of  the
     kstatqueue(9F) functions.

SEE ALSO




SunOS 5.11           Last change: 4 Apr 1994                    1






Data Structures for Drivers                          kstatio(9S)



     kstatcreate(9F),   kstatnamedinit(9F),   kstatqueue(9F),
     kstatrunqbacktowaitq(9F),          kstatrunqenter(9F),
     kstatrunqexit(9F),                  kstatwaitqenter(9F),
     kstatwaitqexit(9F), kstatwaitqtorunq(9F)


     Writing Device Drivers
















































SunOS 5.11           Last change: 4 Apr 1994                    2