Manual Pages for UNIX Operating System command usage for man kstat_chain_update

Kernel Statistics Library Functions    kstat_chain_update(3KSTAT)



NAME
     kstat_chain_update - update the kstat header chain

SYNOPSIS
     cc [ flag... ] file... -lkstat [ library...]
     #include 



     kid_t kstat_chain_update(kstat_ctl_t *kc);


DESCRIPTION
     The kstat_chain_update() function brings  the  user's  kstat
     header  chain  in  sync  with  that of the kernel. The kstat
     chain is a linked list of kstat headers  (kstat_t's) pointed
     to    by    kc->kc_chain,    which    is    initialized   by
     kstat_open(3KSTAT). This chain constitutes  a  list  of  all
     kstats currently in the system.


     During normal operation, the kernel creates new  kstats  and
     delete  old  ones  as various device instances are added and
     removed, thereby causing the user's copy of the kstat  chain
     to  become  out  of  date. The kstat_chain_update() function
     detects this condition by  comparing  the  kernel's  current
     kstat  chain  ID (KCID), which is incremented every time the
     kstat chain changes, to the user's KCID, kc->kc_chain_id. If
     the  KCIDs match, kstat_chain_update() does nothing.  Other-
     wise, it deletes any invalid kstat headers from  the  user's
     kstat  chain, adds any new ones, and sets kc->kc_chain_id to
     the new KCID. All other kstat headers in  the  user's  kstat
     chain are unmodified.

RETURN VALUES
     Upon successful completion, kstat_chain_update() returns the
     new  KCID if the kstat chain has changed and 0 if it has not
     changed. Otherwise, it returns -1 and sets errno to indicate
     the error.

ERRORS
     The kstat_chain_update() function will fail if:

     EAGAIN       The kstat was temporarily unavailable for read-
                  ing or writing.


     ENOMEM       Insufficient storage space is available.


     ENXIO        The given kstat could not be located for  read-
                  ing.



SunOS 5.11          Last change: 13 Apr 2010                    1






Kernel Statistics Library Functions    kstat_chain_update(3KSTAT)



     EOVERFLOW    The data for the given kstat was too  large  to
                  be stored in the structure.


FILES
     /dev/kstat    kernel statistics driver


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe with exceptions     |
    |_____________________________|_____________________________|



     The kstat_chain_update() function is MT-Safe with the excep-
     tion  that  only one thread may actively use a kstat_ctl_t *
     value at any time. Synchronization is left to  the  applica-
     tion.

SEE ALSO
     kstat(3KSTAT),   kstat_lookup(3KSTAT),   kstat_open(3KSTAT),
     kstat_read(3KSTAT), attributes(5)























SunOS 5.11          Last change: 13 Apr 2010                    2