SPECIFICDATA(9)

NAME
specificdata, specificdata_domain_create, specificdata_domain_delete, specificdata_key_create, specificdata_key_delete, specificdata_init, specificdata_fini, specificdata_getspecific, specificdata_getspecific_unlocked, specificdata_setspecific, specificdata_setspecific_nowait - manipulate arbitrary data attached to objects

SYNOPSIS
#include <sys/specificdata.h>
specificdata_domain_t
specificdata_domain_create();
void
specificdata_domain_delete(specificdata_domain_t sd);
int
specificdata_key_create(specificdata_domain_t sd, specificdata_key_t *keyp, specificdata_dtor_t dtor);
void
specificdata_key_delete(specificdata_domain_t sd, specificdata_key_t key);
int
specificdata_init(specificdata_domain_t sd, specificdata_reference *ref);
void
specificdata_fini(specificdata_domain_t sd, specificdata_reference *ref);
void *
specificdata_getspecific(specificdata_domain_t sd, specificdata_reference *ref, specificdata_key_t key);
void *
specificdata_getspecific_unlocked(specificdata_domain_t sd, specificdata_reference *ref, specificdata_key_t key);
void
specificdata_setspecific(specificdata_domain_t sd, specificdata_reference *ref, specificdata_key_t key, void *data);
int
specificdata_setspecific_nowait(specificdata_domain_t sd, specificdata_reference *ref, specificdata_key_t key, void *data);

DESCRIPTION
The specificdata facility provides a mechanism for storing arbitrary data, identified by an index key, within containers which exist within the objects associated with a particular domain.

FUNCTIONS

specificdata_domain_create()
    Create and initialize a new domain.

specificdata_domain_delete(sd)
    Deletes domain sd.

specificdata_key_create(sd, keyp, dtor)
    Create a new key for sd. If the dtor argument is not NULL, it specifies a destructor which will be called when a datum associated with the specified key is deleted from a container within the sd. The unique identifier of the created key is returned in keyp.

specificdata_key_delete(sd, key)
    Delete a key for sd, and delete any associated data from all containers within the domain.

specificdata_init(sd, ref)
    Initialize the container ref for use in sd.

specificdata_fini(sd, ref)
    Destroy the container ref, and destroy all of the data stuffed into the container.

specificdata_getspecific(sd, ref, key)
    Retrieve the datum from the container ref associated with key.

specificdata_getspecific_unlocked(sd, ref, key)
    Retrieve the datum from the container ref associated with key in a lockless manner. Care must be taken to ensure that no other thread could cause ref to become invalid (i.e. point at the wrong container) by issuing a setspecific() call or by destroying the container.

specificdata_setspecific(sd, ref, key, data)
    Store data in the container ref and associate it with key. If a datum has previously been stored, the new value replaces the original; the original value is not destroyed, i.e. its destructor is not invoked. Note that there is no provision for removing a datum without replacing it.

specificdata_setspecific_nowait(sd, ref, key, data)
    (Unimplemented)

CODE REFERENCES
The specificdata functionality is implemented in sys/kern/subr_specificdata.c.

The header file <sys/sys/specificdata.h> describes the public interface.

HISTORY
The specificdata subsystem first appeared in NetBSD 4.0.

AUTHORS
-nosplit The specificdata subsystem was written by Jason Thorpe <thorpej@NetBSD.org>. This manual page was written by Paul Goyette <pgoyette@NetBSD.org>.