sunos man page for kstat_create

kstat_create(9F)					   Kernel Functions for Drivers 					  kstat_create(9F)

NAME
       kstat_create - create and initialize a new kstat

SYNOPSIS
       #include <sys/types.h>
       #include <sys/kstat.h>

       kstat_t *kstat_create(char *module, int instance, char *name, char *class, uchar_t type, ulong_t ndata, uchar_t ks_flag);

INTERFACE LEVEL
       Solaris DDI specific (Solaris DDI)

PARAMETERS
       module	       The name of the provider's module (such as "sd", "esp", ...). The "core" kernel uses the name "unix".

       instance        The provider's instance number, as from ddi_get_instance(9F). Modules which do not have a meaningful instance number should
		       use 0.

       name	       A pointer to a string that uniquely identifies this structure. Only KSTAT_STRLEN - 1 characters are significant.

       class	       The general class that this kstat belongs to. The following classes are currently in use: disk, tape, net, controller,  vm,
		       kvm, hat, streams, kstat, and misc.

       type	       The type of kstat to allocate. Valid types are:

		       "small and bold">KSTAT_TYPE_NAMED

			   Allows more than one data record per kstat.

		       KSTAT_TYPE_INTR

			   Interrupt; only one data record per kstat.

		       KSTAT_TYPE_IO

			   I/O; only one data record per kstat

       ndata	       The number of type-specific data records to allocate.

       flag	       A bit-field of various flags for this kstat. flag is some combination of:

		       KSTAT_FLAG_VIRTUAL

			   Tells  kstat_create() not to allocate memory for the kstat data section; instead, the driver will set the ks_data field
			   to point to the data it wishes to export. This provides a convenient way to export existing data structures.

		       KSTAT_FLAG_WRITABLE

			   Makes the kstat data section writable by root.

		       KSTAT_FLAG_PERSISTENT

			   Indicates that this kstat is to be persistent over time. For persistent kstats, kstat_delete(9F) simply marks the kstat
			   as dormant; a subsequent kstat_create() reactivates the kstat. This feature is provided so that statistics are not lost
			   across driver close/open (such as raw disk I/O on a disk with no mounted partitions.) Note: Persistent kstats cannot be
			   virtual, since ks_data points to garbage as soon as the driver goes away.

DESCRIPTION
       kstat_create()  is  used in conjunction with kstat_install(9F) to allocate and initialize a kstat(9S) structure. The method is generally as
       follows:

       kstat_create() allocates and performs necessary system initialization of a kstat(9S) structure. kstat_create()  allocates  memory  for  the
       entire  kstat  (header  plus  data),  initializes  all header fields, initializes the data section to all zeroes, assigns a unique kstat ID
       (KID), and puts the kstat onto the system's kstat chain. The returned kstat is marked invalid because the provider (caller) has not yet had
       a chance to initialize the data section.

       After  a  successful  call  to kstat_create() the driver must perform any necessary initialization of the data section (such as setting the
       name fields in a kstat of type KSTAT_TYPE_NAMED). Virtual kstats must have the ks_data field set at this time. The provider  may  also  set
       the ks_update, ks_private, and ks_lock fields if necessary.

       Once the kstat is completely initialized, kstat_install(9F) is used to make the kstat accessible to the outside world.

RETURN VALUES
       If successful, kstat_create() returns a pointer to the allocated kstat. NULL is returned upon failure.

CONTEXT
       kstat_create() can be called from user or kernel context.

EXAMPLES
       Example 1: Allocating and Initializing a kstat Structure

       pkstat_t  *ksp;
	    ksp = kstat_create(module, instance, name, class, type, ndata, flags);
	    if (ksp) {
	       /* ... provider initialization, if necessary */
	       kstat_install(ksp);
	    }

SEE ALSO
       kstat(3KSTAT), ddi_get_instance(9F), kstat_delete(9F), kstat_install(9F), kstat_named_init(9F), kstat(9S), kstat_named(9S)

       Writing Device Drivers

SunOS 5.10							    10 Sep 1994 						  kstat_create(9F)