kstat_chain_update(3kstat) [opensolaris man page]

kstat_chain_update(3KSTAT)				Kernel Statistics Library Functions				kstat_chain_update(3KSTAT)

NAME

       kstat_chain_update - update the kstat header chain

SYNOPSIS

       cc [ flag... ] file... -lkstat [ library...]
       #include <kstat.h>

       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 caus-
       ing the user's copy of the kstat chain to become out of date.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.  Otherwise, 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. Other-
       wise, 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 reading or writing.

       ENOMEM	    Insufficient storage space is available.

       ENXIO	    The given kstat could not be located for reading.

       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 attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Stable			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

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

SunOS 5.11							    3 Aug 2004						kstat_chain_update(3KSTAT)

kstat_read(3KSTAT)					Kernel Statistics Library Functions					kstat_read(3KSTAT)

NAME

       kstat_read, kstat_write - read or write kstat data

SYNOPSIS

       cc [ flag... ] file... -lkstat [ library... ]
       #include <kstat.h>

       kid_t kstat_read(kstat_ctl_t *kc, kstat_t *ksp, void *buf);

       kid_t kstat_write(kstat_ctl_t *kc, kstat_t *ksp, void *buf);

DESCRIPTION

       The  kstat_read() function gets data from the kernel for the kstat pointed to by ksp. The ksp->ks_data field is automatically allocated (or
       reallocated) to be large enough to hold all of the data. The ksp->ks_ndata field is set to the number of data fields, ksp->ks_data_size	is
       set  to the total size of the data, and ksp->ks_snaptime is set to the high-resolution time at which the data snapshot was taken. If buf is
       non-null, the data is copied from ksp->ks_data to buf.

       The kstat_write() function writes data from buf, or from ksp->ks_data if buf is NULL, to the corresponding kstat in the kernel.	 Only  the
       superuser can use kstat_write().

RETURN VALUES

       Upon  successful  completion,  kstat_read()  and  kstat_write() return the current kstat chain ID (KCID). Otherwise, they return -1 and set
       errno to indicate the error.

ERRORS

       The kstat_read() and kstat_write() functions will fail if:

       EACCES	       An attempt was made to write to a non-writable kstat.

       EAGAIN	       The kstat was temporarily unavailable for reading or writing.

       EINVAL	       An attempt was made to write data to a kstat, but the number of elements or the data size does not match.

       ENOMEM	       Insufficient storage space is available.

       ENXIO	       The given kstat could not be located for reading or writing.

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

       EPERM	       An attempt was made to write to a kstat, but {PRIV_SYS_CONFIG} was not asserted in the effective privilege set.

FILES

       /dev/kstat      kernel statistics driver

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Stable			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       kstat(3KSTAT), kstat_chain_update(3KSTAT), kstat_lookup(3KSTAT), kstat_open(3KSTAT), attributes(5), privileges(5)

SunOS 5.10							    3 Aug 2004							kstat_read(3KSTAT)