NetBSD/share/man/man9/pool_cache.9

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.\" $NetBSD: pool_cache.9,v 1.5 2007/02/16 23:13:05 rmind Exp $
.\"
.\" Copyright (c)2003 YAMAMOTO Takashi,
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"
.\" following copyright notice is from sys/kern/subr_pool.c.
.\" they are here because i took some comments from it. yamt@NetBSD.org
.\"
.\"
.\"/*-
.\" * Copyright (c) 1997, 1999, 2000 The NetBSD Foundation, Inc.
.\" * All rights reserved.
.\" *
.\" * This code is derived from software contributed to The NetBSD Foundation
.\" * by Paul Kranenburg; by Jason R. Thorpe of the Numerical Aerospace
.\" * Simulation Facility, NASA Ames Research Center.
.\" *
.\" * Redistribution and use in source and binary forms, with or without
.\" * modification, are permitted provided that the following conditions
.\" * are met:
.\" * 1. Redistributions of source code must retain the above copyright
.\" * notice, this list of conditions and the following disclaimer.
.\" * 2. Redistributions in binary form must reproduce the above copyright
.\" * notice, this list of conditions and the following disclaimer in the
.\" * documentation and/or other materials provided with the distribution.
.\" * 3. All advertising materials mentioning features or use of this software
.\" * must display the following acknowledgement:
.\" * This product includes software developed by the NetBSD
.\" * Foundation, Inc. and its contributors.
.\" * 4. Neither the name of The NetBSD Foundation nor the names of its
.\" * contributors may be used to endorse or promote products derived
.\" * from this software without specific prior written permission.
.\" *
.\" * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" * POSSIBILITY OF SUCH DAMAGE.
.\" */
.\"
.\" ------------------------------------------------------------
.Dd September 8, 2003
.Dt POOL_CACHE 9
.Os
.\" ------------------------------------------------------------
.Sh NAME
.Nm pool_cache ,
.Nm pool_cache_init ,
.Nm pool_cache_destroy ,
.Nm pool_cache_get_paddr ,
.Nm pool_cache_get ,
.Nm pool_cache_put_paddr ,
.Nm pool_cache_put ,
.Nm pool_cache_destruct_object ,
.Nm pool_cache_invalidate
.Nd resource-pool cache manager
.\" ------------------------------------------------------------
.Sh SYNOPSIS
.In sys/pool.h
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn pool_cache_init \
"struct pool_cache *pc" "struct pool *pp" \
"int (*ctor)(void *, void *, int)" "void (*dtor)(void *, void *)" "void *arg"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn pool_cache_destroy \
"struct pool_cache *pc"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void *
.Fn pool_cache_get_paddr \
"struct pool_cache *pc" "int flags" "paddr_t *pap"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void *
.Fn pool_cache_get \
"struct pool_cache *pc" "int flags"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn pool_cache_put_paddr \
"struct pool_cache *pc" "void *object" "paddr_t pa"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn pool_cache_put \
"struct pool_cache *pc" "void *object"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn pool_cache_destruct_object \
"struct pool_cache *pc" "void *object"
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn pool_cache_invalidate \
"struct pool_cache *pc"
.\" ------------------------------------------------------------
.Sh DESCRIPTION
The
.Nm
utility routines are provided to support caching of constructed objects,
similar to the Solaris SLAB allocator.
.Nm
uses
.Xr pool 9
to allocate memory areas used for objects.
If the pool must be protected from interrupts,
.Nm
routines expect to be called at the appropriate interrupt priority level.
.\" ------------------------------------------------------------
.Sh FUNCTIONS
.Bl -tag -width compact
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_init "pc" "pp" "ctor" "dtor" "arg"
Initialize a pool cache
.Fa pc .
The pool
.Fa pp
should be initialized by the caller in advance.
.Fa ctor
and
.Fa dtor
are object constructor and destructor.
They can be
.Dv NULL .
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_destroy "pc"
Destroy a pool cache
.Fa pc .
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_get_paddr "pc" "flags" "pap"
Get an object from a pool cache
.Fa pc .
If
.Fa pap
is not
.Dv NULL ,
physical address of the object or
.Dv POOL_PADDR_INVALID
will be returned via it.
.Fa flags
will be passed to
.Fn pool_get
function of the backing
.Xr pool 9
and the object constructor specified when the pool cache is created by
.Fn pool_cache_init .
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_get "pc" "flags"
.Fn pool_cache_get
is the same as
.Fn pool_cache_get_paddr
with
.Dv NULL
.Fa pap
argument.
It's implemented as a macro.
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_put_paddr "pc" "object" "pa"
Put an object
.Fa object
back to the pool cache
.Fa pc .
.Fa pa
should be physical address of the object
.Fa object
or
.Dv POOL_PADDR_INVALID .
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_put "pc" "object"
.Fn pool_cache_put
is the same as
.Fn pool_cache_put_paddr
with
.Dv POOL_PADDR_INVALID
.Fa pa
argument.
It's implemented as a macro.
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_destruct_object "pc" "object"
Force destruction of an object
.Fa object
and its release back into the pool.
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.It Fn pool_cache_invalidate "pc"
Invalidate a pool cache
.Fa pc .
Destruct and release all of the cached objects.
.El
.\" ------------------------------------------------------------
.Sh CODE REFERENCES
This section describes places within the
.Nx
source tree where actual code implementing the
.Nm
subsystem
can be found.
All pathnames are relative to
.Pa /usr/src .
.Pp
The
.Nm
subsystem is implemented within the file
.Pa sys/kern/subr_pool.c .
.Sh SEE ALSO
.Xr intro 9 ,
.Xr malloc 9 ,
.Xr memoryallocators 9 ,
.Xr pool 9