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