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subr_specificdata.c revision 1.5.2.3
      1  1.5.2.3  yamt /*	$NetBSD: subr_specificdata.c,v 1.5.2.3 2006/12/10 07:18:45 yamt Exp $	*/
      2  1.5.2.2  yamt 
      3  1.5.2.2  yamt /*-
      4  1.5.2.2  yamt  * Copyright (c) 2006 The NetBSD Foundation, Inc.
      5  1.5.2.2  yamt  * All rights reserved.
      6  1.5.2.2  yamt  *
      7  1.5.2.2  yamt  * This code is derived from software contributed to The NetBSD Foundation
      8  1.5.2.2  yamt  * by Jason R. Thorpe.
      9  1.5.2.2  yamt  *
     10  1.5.2.2  yamt  * Redistribution and use in source and binary forms, with or without
     11  1.5.2.2  yamt  * modification, are permitted provided that the following conditions
     12  1.5.2.2  yamt  * are met:
     13  1.5.2.2  yamt  * 1. Redistributions of source code must retain the above copyright
     14  1.5.2.2  yamt  *    notice, this list of conditions and the following disclaimer.
     15  1.5.2.2  yamt  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.5.2.2  yamt  *    notice, this list of conditions and the following disclaimer in the
     17  1.5.2.2  yamt  *    documentation and/or other materials provided with the distribution.
     18  1.5.2.2  yamt  * 3. All advertising materials mentioning features or use of this software
     19  1.5.2.2  yamt  *    must display the following acknowledgement:
     20  1.5.2.2  yamt  *	This product includes software developed by the NetBSD
     21  1.5.2.2  yamt  *	Foundation, Inc. and its contributors.
     22  1.5.2.2  yamt  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  1.5.2.2  yamt  *    contributors may be used to endorse or promote products derived
     24  1.5.2.2  yamt  *    from this software without specific prior written permission.
     25  1.5.2.2  yamt  *
     26  1.5.2.2  yamt  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  1.5.2.2  yamt  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  1.5.2.2  yamt  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  1.5.2.2  yamt  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  1.5.2.2  yamt  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  1.5.2.2  yamt  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  1.5.2.2  yamt  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  1.5.2.2  yamt  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  1.5.2.2  yamt  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  1.5.2.2  yamt  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  1.5.2.2  yamt  * POSSIBILITY OF SUCH DAMAGE.
     37  1.5.2.2  yamt  */
     38  1.5.2.2  yamt 
     39  1.5.2.2  yamt /*-
     40  1.5.2.2  yamt  * Copyright (c) 2006 YAMAMOTO Takashi.
     41  1.5.2.2  yamt  * All rights reserved.
     42  1.5.2.2  yamt  *
     43  1.5.2.2  yamt  * Redistribution and use in source and binary forms, with or without
     44  1.5.2.2  yamt  * modification, are permitted provided that the following conditions
     45  1.5.2.2  yamt  * are met:
     46  1.5.2.2  yamt  * 1. Redistributions of source code must retain the above copyright
     47  1.5.2.2  yamt  *    notice, this list of conditions and the following disclaimer.
     48  1.5.2.2  yamt  * 2. Redistributions in binary form must reproduce the above copyright
     49  1.5.2.2  yamt  *    notice, this list of conditions and the following disclaimer in the
     50  1.5.2.2  yamt  *    documentation and/or other materials provided with the distribution.
     51  1.5.2.2  yamt  *
     52  1.5.2.2  yamt  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     53  1.5.2.2  yamt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     54  1.5.2.2  yamt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     55  1.5.2.2  yamt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     56  1.5.2.2  yamt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     57  1.5.2.2  yamt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     58  1.5.2.2  yamt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     59  1.5.2.2  yamt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     60  1.5.2.2  yamt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     61  1.5.2.2  yamt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     62  1.5.2.2  yamt  * SUCH DAMAGE.
     63  1.5.2.2  yamt  */
     64  1.5.2.2  yamt 
     65  1.5.2.2  yamt #include <sys/cdefs.h>
     66  1.5.2.3  yamt __KERNEL_RCSID(0, "$NetBSD: subr_specificdata.c,v 1.5.2.3 2006/12/10 07:18:45 yamt Exp $");
     67  1.5.2.2  yamt 
     68  1.5.2.2  yamt #include <sys/param.h>
     69  1.5.2.2  yamt #include <sys/kmem.h>
     70  1.5.2.2  yamt #include <sys/proc.h>
     71  1.5.2.2  yamt #include <sys/specificdata.h>
     72  1.5.2.2  yamt #include <sys/queue.h>
     73  1.5.2.2  yamt 
     74  1.5.2.2  yamt /*
     75  1.5.2.2  yamt  * Locking notes:
     76  1.5.2.2  yamt  *
     77  1.5.2.2  yamt  * The specdataref_container pointer in the specificdata_reference
     78  1.5.2.2  yamt  * is volatile.  To read it, you must hold EITHER the domain lock
     79  1.5.2.2  yamt  * or the ref lock.  To write it, you must hold BOTH the domain lock
     80  1.5.2.2  yamt  * and the ref lock.  The locks must be acquired in the following
     81  1.5.2.2  yamt  * order:
     82  1.5.2.2  yamt  *	domain -> ref
     83  1.5.2.2  yamt  */
     84  1.5.2.2  yamt 
     85  1.5.2.2  yamt typedef struct {
     86  1.5.2.2  yamt 	specificdata_dtor_t	ski_dtor;
     87  1.5.2.2  yamt } specificdata_key_impl;
     88  1.5.2.2  yamt 
     89  1.5.2.2  yamt struct specificdata_container {
     90  1.5.2.2  yamt 	size_t		sc_nkey;
     91  1.5.2.2  yamt 	LIST_ENTRY(specificdata_container) sc_list;
     92  1.5.2.2  yamt 	void *		sc_data[];	/* variable length */
     93  1.5.2.2  yamt };
     94  1.5.2.2  yamt 
     95  1.5.2.2  yamt #define	SPECIFICDATA_CONTAINER_BYTESIZE(n)		\
     96  1.5.2.2  yamt 	(sizeof(struct specificdata_container) + ((n) * sizeof(void *)))
     97  1.5.2.2  yamt 
     98  1.5.2.2  yamt struct specificdata_domain {
     99  1.5.2.2  yamt 	struct lock	sd_lock;
    100  1.5.2.2  yamt 	unsigned int	sd_nkey;
    101  1.5.2.2  yamt 	LIST_HEAD(, specificdata_container) sd_list;
    102  1.5.2.2  yamt 	specificdata_key_impl *sd_keys;
    103  1.5.2.2  yamt };
    104  1.5.2.2  yamt 
    105  1.5.2.2  yamt #define	specdataref_lock_init(ref)			\
    106  1.5.2.2  yamt 				simple_lock_init(&(ref)->specdataref_slock)
    107  1.5.2.2  yamt #define	specdataref_lock(ref)	simple_lock(&(ref)->specdataref_slock)
    108  1.5.2.2  yamt #define	specdataref_unlock(ref)	simple_unlock(&(ref)->specdataref_slock)
    109  1.5.2.2  yamt 
    110  1.5.2.2  yamt static void
    111  1.5.2.2  yamt specificdata_domain_lock(specificdata_domain_t sd)
    112  1.5.2.2  yamt {
    113  1.5.2.2  yamt 
    114  1.5.2.2  yamt 	ASSERT_SLEEPABLE(NULL, __func__);
    115  1.5.2.2  yamt 	lockmgr(&sd->sd_lock, LK_EXCLUSIVE, 0);
    116  1.5.2.2  yamt }
    117  1.5.2.2  yamt 
    118  1.5.2.2  yamt static void
    119  1.5.2.2  yamt specificdata_domain_unlock(specificdata_domain_t sd)
    120  1.5.2.2  yamt {
    121  1.5.2.2  yamt 
    122  1.5.2.2  yamt 	lockmgr(&sd->sd_lock, LK_RELEASE, 0);
    123  1.5.2.2  yamt }
    124  1.5.2.2  yamt 
    125  1.5.2.2  yamt static void
    126  1.5.2.2  yamt specificdata_container_link(specificdata_domain_t sd,
    127  1.5.2.2  yamt 			    specificdata_container_t sc)
    128  1.5.2.2  yamt {
    129  1.5.2.2  yamt 
    130  1.5.2.2  yamt 	LIST_INSERT_HEAD(&sd->sd_list, sc, sc_list);
    131  1.5.2.2  yamt }
    132  1.5.2.2  yamt 
    133  1.5.2.2  yamt static void
    134  1.5.2.3  yamt specificdata_container_unlink(specificdata_domain_t sd,
    135  1.5.2.2  yamt 			      specificdata_container_t sc)
    136  1.5.2.2  yamt {
    137  1.5.2.2  yamt 
    138  1.5.2.2  yamt 	LIST_REMOVE(sc, sc_list);
    139  1.5.2.2  yamt }
    140  1.5.2.2  yamt 
    141  1.5.2.2  yamt static void
    142  1.5.2.2  yamt specificdata_destroy_datum(specificdata_domain_t sd,
    143  1.5.2.2  yamt 			   specificdata_container_t sc, specificdata_key_t key)
    144  1.5.2.2  yamt {
    145  1.5.2.2  yamt 	specificdata_dtor_t dtor;
    146  1.5.2.2  yamt 	void *data;
    147  1.5.2.2  yamt 
    148  1.5.2.2  yamt 	if (key >= sc->sc_nkey)
    149  1.5.2.2  yamt 		return;
    150  1.5.2.2  yamt 
    151  1.5.2.2  yamt 	KASSERT(key < sd->sd_nkey);
    152  1.5.2.2  yamt 
    153  1.5.2.2  yamt 	data = sc->sc_data[key];
    154  1.5.2.2  yamt 	dtor = sd->sd_keys[key].ski_dtor;
    155  1.5.2.2  yamt 
    156  1.5.2.2  yamt 	if (dtor != NULL) {
    157  1.5.2.2  yamt 		if (data != NULL) {
    158  1.5.2.2  yamt 			sc->sc_data[key] = NULL;
    159  1.5.2.2  yamt 			(*dtor)(data);
    160  1.5.2.2  yamt 		}
    161  1.5.2.2  yamt 	} else {
    162  1.5.2.2  yamt 		KASSERT(data == NULL);
    163  1.5.2.2  yamt 	}
    164  1.5.2.2  yamt }
    165  1.5.2.2  yamt 
    166  1.5.2.2  yamt static void
    167  1.5.2.3  yamt specificdata_noop_dtor(void *data)
    168  1.5.2.2  yamt {
    169  1.5.2.2  yamt 
    170  1.5.2.2  yamt 	/* nothing */
    171  1.5.2.2  yamt }
    172  1.5.2.2  yamt 
    173  1.5.2.2  yamt /*
    174  1.5.2.2  yamt  * specificdata_domain_create --
    175  1.5.2.2  yamt  *	Create a specifidata domain.
    176  1.5.2.2  yamt  */
    177  1.5.2.2  yamt specificdata_domain_t
    178  1.5.2.2  yamt specificdata_domain_create(void)
    179  1.5.2.2  yamt {
    180  1.5.2.2  yamt 	specificdata_domain_t sd;
    181  1.5.2.2  yamt 
    182  1.5.2.2  yamt 	sd = kmem_zalloc(sizeof(*sd), KM_SLEEP);
    183  1.5.2.2  yamt 	KASSERT(sd != NULL);
    184  1.5.2.2  yamt 	lockinit(&sd->sd_lock, PLOCK, "specdata", 0, 0);
    185  1.5.2.2  yamt 	LIST_INIT(&sd->sd_list);
    186  1.5.2.2  yamt 
    187  1.5.2.2  yamt 	return (sd);
    188  1.5.2.2  yamt }
    189  1.5.2.2  yamt 
    190  1.5.2.2  yamt /*
    191  1.5.2.2  yamt  * specificdata_domain_delete --
    192  1.5.2.2  yamt  *	Destroy a specifidata domain.
    193  1.5.2.2  yamt  */
    194  1.5.2.2  yamt void
    195  1.5.2.3  yamt specificdata_domain_delete(specificdata_domain_t sd)
    196  1.5.2.2  yamt {
    197  1.5.2.2  yamt 
    198  1.5.2.2  yamt 	panic("specificdata_domain_delete: not implemented");
    199  1.5.2.2  yamt }
    200  1.5.2.2  yamt 
    201  1.5.2.2  yamt /*
    202  1.5.2.2  yamt  * specificdata_key_create --
    203  1.5.2.2  yamt  *	Create a specificdata key for a domain.
    204  1.5.2.2  yamt  *
    205  1.5.2.2  yamt  *	Note: This is a rare operation.
    206  1.5.2.2  yamt  */
    207  1.5.2.2  yamt int
    208  1.5.2.2  yamt specificdata_key_create(specificdata_domain_t sd, specificdata_key_t *keyp,
    209  1.5.2.2  yamt 			specificdata_dtor_t dtor)
    210  1.5.2.2  yamt {
    211  1.5.2.2  yamt 	specificdata_key_impl *newkeys;
    212  1.5.2.2  yamt 	specificdata_key_t key = 0;
    213  1.5.2.2  yamt 	size_t nsz;
    214  1.5.2.2  yamt 
    215  1.5.2.2  yamt 	ASSERT_SLEEPABLE(NULL, __func__);
    216  1.5.2.2  yamt 
    217  1.5.2.2  yamt 	if (dtor == NULL)
    218  1.5.2.2  yamt 		dtor = specificdata_noop_dtor;
    219  1.5.2.2  yamt 
    220  1.5.2.2  yamt 	specificdata_domain_lock(sd);
    221  1.5.2.2  yamt 
    222  1.5.2.2  yamt 	if (sd->sd_keys == NULL)
    223  1.5.2.2  yamt 		goto needalloc;
    224  1.5.2.2  yamt 
    225  1.5.2.2  yamt 	for (; key < sd->sd_nkey; key++) {
    226  1.5.2.2  yamt 		if (sd->sd_keys[key].ski_dtor == NULL)
    227  1.5.2.2  yamt 			goto gotit;
    228  1.5.2.2  yamt 	}
    229  1.5.2.2  yamt 
    230  1.5.2.2  yamt  needalloc:
    231  1.5.2.2  yamt 	nsz = (sd->sd_nkey + 1) * sizeof(*newkeys);
    232  1.5.2.2  yamt 	newkeys = kmem_zalloc(nsz, KM_SLEEP);
    233  1.5.2.2  yamt 	KASSERT(newkeys != NULL);
    234  1.5.2.2  yamt 	if (sd->sd_keys != NULL) {
    235  1.5.2.2  yamt 		size_t osz = sd->sd_nkey * sizeof(*newkeys);
    236  1.5.2.2  yamt 		memcpy(newkeys, sd->sd_keys, osz);
    237  1.5.2.2  yamt 		kmem_free(sd->sd_keys, osz);
    238  1.5.2.2  yamt 	}
    239  1.5.2.2  yamt 	sd->sd_keys = newkeys;
    240  1.5.2.2  yamt 	sd->sd_nkey++;
    241  1.5.2.2  yamt  gotit:
    242  1.5.2.2  yamt 	sd->sd_keys[key].ski_dtor = dtor;
    243  1.5.2.2  yamt 
    244  1.5.2.2  yamt 	specificdata_domain_unlock(sd);
    245  1.5.2.2  yamt 
    246  1.5.2.2  yamt 	*keyp = key;
    247  1.5.2.2  yamt 	return (0);
    248  1.5.2.2  yamt }
    249  1.5.2.2  yamt 
    250  1.5.2.2  yamt /*
    251  1.5.2.2  yamt  * specificdata_key_delete --
    252  1.5.2.2  yamt  *	Destroy a specificdata key for a domain.
    253  1.5.2.2  yamt  *
    254  1.5.2.2  yamt  *	Note: This is a rare operation.
    255  1.5.2.2  yamt  */
    256  1.5.2.2  yamt void
    257  1.5.2.2  yamt specificdata_key_delete(specificdata_domain_t sd, specificdata_key_t key)
    258  1.5.2.2  yamt {
    259  1.5.2.2  yamt 	specificdata_container_t sc;
    260  1.5.2.2  yamt 
    261  1.5.2.2  yamt 	specificdata_domain_lock(sd);
    262  1.5.2.2  yamt 
    263  1.5.2.2  yamt 	if (key >= sd->sd_nkey)
    264  1.5.2.2  yamt 		goto out;
    265  1.5.2.2  yamt 
    266  1.5.2.2  yamt 	/*
    267  1.5.2.2  yamt 	 * Traverse all of the specificdata containers in the domain
    268  1.5.2.2  yamt 	 * and the destroy the datum for the dying key.
    269  1.5.2.2  yamt 	 */
    270  1.5.2.2  yamt 	LIST_FOREACH(sc, &sd->sd_list, sc_list) {
    271  1.5.2.2  yamt 		specificdata_destroy_datum(sd, sc, key);
    272  1.5.2.2  yamt 	}
    273  1.5.2.2  yamt 
    274  1.5.2.2  yamt 	sd->sd_keys[key].ski_dtor = NULL;
    275  1.5.2.2  yamt 
    276  1.5.2.2  yamt  out:
    277  1.5.2.2  yamt 	specificdata_domain_unlock(sd);
    278  1.5.2.2  yamt }
    279  1.5.2.2  yamt 
    280  1.5.2.2  yamt /*
    281  1.5.2.2  yamt  * specificdata_init --
    282  1.5.2.2  yamt  *	Initialize a specificdata container for operation in the
    283  1.5.2.2  yamt  *	specified domain.
    284  1.5.2.2  yamt  */
    285  1.5.2.2  yamt int
    286  1.5.2.3  yamt specificdata_init(specificdata_domain_t sd, specificdata_reference *ref)
    287  1.5.2.2  yamt {
    288  1.5.2.2  yamt 
    289  1.5.2.2  yamt 	/*
    290  1.5.2.2  yamt 	 * Just NULL-out the container pointer; we'll allocate the
    291  1.5.2.2  yamt 	 * container the first time specificdata is put into it.
    292  1.5.2.2  yamt 	 */
    293  1.5.2.2  yamt 	ref->specdataref_container = NULL;
    294  1.5.2.2  yamt 	specdataref_lock_init(ref);
    295  1.5.2.2  yamt 
    296  1.5.2.2  yamt 	return (0);
    297  1.5.2.2  yamt }
    298  1.5.2.2  yamt 
    299  1.5.2.2  yamt /*
    300  1.5.2.2  yamt  * specificdata_fini --
    301  1.5.2.2  yamt  *	Destroy a specificdata container.  We destroy all of the datums
    302  1.5.2.2  yamt  *	stuffed into the container just as if the key were destroyed.
    303  1.5.2.2  yamt  */
    304  1.5.2.2  yamt void
    305  1.5.2.2  yamt specificdata_fini(specificdata_domain_t sd, specificdata_reference *ref)
    306  1.5.2.2  yamt {
    307  1.5.2.2  yamt 	specificdata_container_t sc;
    308  1.5.2.2  yamt 	specificdata_key_t key;
    309  1.5.2.2  yamt 
    310  1.5.2.2  yamt 	ASSERT_SLEEPABLE(NULL, __func__);
    311  1.5.2.2  yamt 
    312  1.5.2.2  yamt 	sc = ref->specdataref_container;
    313  1.5.2.2  yamt 	if (sc == NULL)
    314  1.5.2.2  yamt 		return;
    315  1.5.2.2  yamt 	ref->specdataref_container = NULL;
    316  1.5.2.2  yamt 
    317  1.5.2.2  yamt 	specificdata_domain_lock(sd);
    318  1.5.2.2  yamt 
    319  1.5.2.2  yamt 	specificdata_container_unlink(sd, sc);
    320  1.5.2.2  yamt 	for (key = 0; key < sc->sc_nkey; key++) {
    321  1.5.2.2  yamt 		specificdata_destroy_datum(sd, sc, key);
    322  1.5.2.2  yamt 	}
    323  1.5.2.2  yamt 
    324  1.5.2.2  yamt 	specificdata_domain_unlock(sd);
    325  1.5.2.2  yamt 
    326  1.5.2.2  yamt 	kmem_free(sc, SPECIFICDATA_CONTAINER_BYTESIZE(sc->sc_nkey));
    327  1.5.2.2  yamt }
    328  1.5.2.2  yamt 
    329  1.5.2.2  yamt /*
    330  1.5.2.2  yamt  * specificdata_getspecific --
    331  1.5.2.2  yamt  *	Get a datum from a container.
    332  1.5.2.2  yamt  *
    333  1.5.2.2  yamt  *	Note: This routine is guaranteed not to sleep.
    334  1.5.2.2  yamt  */
    335  1.5.2.2  yamt void *
    336  1.5.2.3  yamt specificdata_getspecific(specificdata_domain_t sd, specificdata_reference *ref,
    337  1.5.2.3  yamt 			 specificdata_key_t key)
    338  1.5.2.2  yamt {
    339  1.5.2.2  yamt 	specificdata_container_t sc;
    340  1.5.2.2  yamt 	void *data = NULL;
    341  1.5.2.2  yamt 
    342  1.5.2.2  yamt 	specdataref_lock(ref);
    343  1.5.2.2  yamt 
    344  1.5.2.2  yamt 	sc = ref->specdataref_container;
    345  1.5.2.2  yamt 	if (sc != NULL && key < sc->sc_nkey)
    346  1.5.2.2  yamt 		data = sc->sc_data[key];
    347  1.5.2.2  yamt 
    348  1.5.2.2  yamt 	specdataref_unlock(ref);
    349  1.5.2.2  yamt 
    350  1.5.2.2  yamt 	return (data);
    351  1.5.2.2  yamt }
    352  1.5.2.2  yamt 
    353  1.5.2.2  yamt /*
    354  1.5.2.2  yamt  * specificdata_getspecific_unlocked --
    355  1.5.2.2  yamt  *	Get a datum from a container in a lockless fashion.
    356  1.5.2.2  yamt  *
    357  1.5.2.2  yamt  *	Note: When using this routine, care must be taken to ensure
    358  1.5.2.2  yamt  *	that no other thread could cause the specificdata_reference
    359  1.5.2.2  yamt  *	to become invalid (i.e. point at the wrong container) by
    360  1.5.2.2  yamt  *	issuing a setspecific call or destroying the container.
    361  1.5.2.2  yamt  *
    362  1.5.2.2  yamt  *	Note #2: This routine is guaranteed not to sleep.
    363  1.5.2.2  yamt  */
    364  1.5.2.2  yamt void *
    365  1.5.2.3  yamt specificdata_getspecific_unlocked(specificdata_domain_t sd,
    366  1.5.2.2  yamt 				  specificdata_reference *ref,
    367  1.5.2.2  yamt 				  specificdata_key_t key)
    368  1.5.2.2  yamt {
    369  1.5.2.2  yamt 	specificdata_container_t sc;
    370  1.5.2.2  yamt 
    371  1.5.2.2  yamt 	sc = ref->specdataref_container;
    372  1.5.2.2  yamt 	if (sc != NULL && key < sc->sc_nkey)
    373  1.5.2.2  yamt 		return (sc->sc_data[key]);
    374  1.5.2.2  yamt 
    375  1.5.2.2  yamt 	return (NULL);
    376  1.5.2.2  yamt }
    377  1.5.2.2  yamt 
    378  1.5.2.3  yamt /*
    379  1.5.2.3  yamt  * specificdata_setspecific --
    380  1.5.2.3  yamt  *      Put a datum into a container.
    381  1.5.2.3  yamt  */
    382  1.5.2.3  yamt void
    383  1.5.2.3  yamt specificdata_setspecific(specificdata_domain_t sd,
    384  1.5.2.3  yamt 			 specificdata_reference *ref,
    385  1.5.2.3  yamt 			 specificdata_key_t key, void *data)
    386  1.5.2.2  yamt {
    387  1.5.2.2  yamt 	specificdata_container_t sc, newsc;
    388  1.5.2.2  yamt 	size_t newnkey, sz;
    389  1.5.2.2  yamt 
    390  1.5.2.2  yamt 	ASSERT_SLEEPABLE(NULL, __func__);
    391  1.5.2.2  yamt 
    392  1.5.2.2  yamt 	specdataref_lock(ref);
    393  1.5.2.2  yamt 
    394  1.5.2.2  yamt 	sc = ref->specdataref_container;
    395  1.5.2.2  yamt 	if (__predict_true(sc != NULL && key < sc->sc_nkey)) {
    396  1.5.2.2  yamt 		sc->sc_data[key] = data;
    397  1.5.2.2  yamt 		specdataref_unlock(ref);
    398  1.5.2.3  yamt 		return;
    399  1.5.2.2  yamt 	}
    400  1.5.2.2  yamt 
    401  1.5.2.2  yamt 	specdataref_unlock(ref);
    402  1.5.2.2  yamt 
    403  1.5.2.2  yamt 	/*
    404  1.5.2.2  yamt 	 * Slow path: need to resize.
    405  1.5.2.2  yamt 	 */
    406  1.5.2.2  yamt 
    407  1.5.2.3  yamt 	specificdata_domain_lock(sd);
    408  1.5.2.2  yamt 	newnkey = sd->sd_nkey;
    409  1.5.2.2  yamt 	if (key >= newnkey) {
    410  1.5.2.2  yamt 		specificdata_domain_unlock(sd);
    411  1.5.2.2  yamt 		panic("specificdata_setspecific");
    412  1.5.2.2  yamt 	}
    413  1.5.2.2  yamt 	sz = SPECIFICDATA_CONTAINER_BYTESIZE(newnkey);
    414  1.5.2.3  yamt 	newsc = kmem_zalloc(sz, KM_SLEEP);
    415  1.5.2.3  yamt 	KASSERT(newsc != NULL);
    416  1.5.2.2  yamt 	newsc->sc_nkey = newnkey;
    417  1.5.2.2  yamt 
    418  1.5.2.2  yamt 	specdataref_lock(ref);
    419  1.5.2.2  yamt 
    420  1.5.2.2  yamt 	sc = ref->specdataref_container;
    421  1.5.2.2  yamt 	if (sc != NULL) {
    422  1.5.2.2  yamt 		if (key < sc->sc_nkey) {
    423  1.5.2.2  yamt 			/*
    424  1.5.2.2  yamt 			 * Someone beat us to the punch.  Unwind and put
    425  1.5.2.2  yamt 			 * the object into the now large enough container.
    426  1.5.2.2  yamt 			 */
    427  1.5.2.2  yamt 			sc->sc_data[key] = data;
    428  1.5.2.2  yamt 			specdataref_unlock(ref);
    429  1.5.2.2  yamt 			specificdata_domain_unlock(sd);
    430  1.5.2.2  yamt 			kmem_free(newsc, sz);
    431  1.5.2.3  yamt 			return;
    432  1.5.2.2  yamt 		}
    433  1.5.2.2  yamt 		specificdata_container_unlink(sd, sc);
    434  1.5.2.2  yamt 		memcpy(newsc->sc_data, sc->sc_data,
    435  1.5.2.2  yamt 		       sc->sc_nkey * sizeof(void *));
    436  1.5.2.2  yamt 	}
    437  1.5.2.2  yamt 	newsc->sc_data[key] = data;
    438  1.5.2.2  yamt 	specificdata_container_link(sd, newsc);
    439  1.5.2.2  yamt 	ref->specdataref_container = newsc;
    440  1.5.2.2  yamt 
    441  1.5.2.2  yamt 	specdataref_unlock(ref);
    442  1.5.2.2  yamt 	specificdata_domain_unlock(sd);
    443  1.5.2.2  yamt 
    444  1.5.2.2  yamt 	if (sc != NULL)
    445  1.5.2.2  yamt 		kmem_free(sc, SPECIFICDATA_CONTAINER_BYTESIZE(sc->sc_nkey));
    446  1.5.2.2  yamt }
    447