zfs-builds-mm/zfs-0.8.4/lib/libuutil/uu_avl.c

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2020-07-19 16:21:53 +02:00
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include "libuutil_common.h"
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/avl.h>
static uu_avl_pool_t uu_null_apool = { &uu_null_apool, &uu_null_apool };
static pthread_mutex_t uu_apool_list_lock = PTHREAD_MUTEX_INITIALIZER;
/*
* The index mark change on every insert and delete, to catch stale
* references.
*
* We leave the low bit alone, since the avl code uses it.
*/
#define INDEX_MAX (sizeof (uintptr_t) - 2)
#define INDEX_NEXT(m) (((m) == INDEX_MAX)? 2 : ((m) + 2) & INDEX_MAX)
#define INDEX_DECODE(i) ((i) & ~INDEX_MAX)
#define INDEX_ENCODE(p, n) (((n) & ~INDEX_MAX) | (p)->ua_index)
#define INDEX_VALID(p, i) (((i) & INDEX_MAX) == (p)->ua_index)
#define INDEX_CHECK(i) (((i) & INDEX_MAX) != 0)
/*
* When an element is inactive (not in a tree), we keep a marked pointer to
* its containing pool in its first word, and a NULL pointer in its second.
*
* On insert, we use these to verify that it comes from the correct pool.
*/
#define NODE_ARRAY(p, n) ((uintptr_t *)((uintptr_t)(n) + \
(pp)->uap_nodeoffset))
#define POOL_TO_MARKER(pp) (((uintptr_t)(pp) | 1))
#define DEAD_MARKER 0xc4
uu_avl_pool_t *
uu_avl_pool_create(const char *name, size_t objsize, size_t nodeoffset,
uu_compare_fn_t *compare_func, uint32_t flags)
{
uu_avl_pool_t *pp, *next, *prev;
if (name == NULL ||
uu_check_name(name, UU_NAME_DOMAIN) == -1 ||
nodeoffset + sizeof (uu_avl_node_t) > objsize ||
compare_func == NULL) {
uu_set_error(UU_ERROR_INVALID_ARGUMENT);
return (NULL);
}
if (flags & ~UU_AVL_POOL_DEBUG) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
pp = uu_zalloc(sizeof (uu_avl_pool_t));
if (pp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
(void) strlcpy(pp->uap_name, name, sizeof (pp->uap_name));
pp->uap_nodeoffset = nodeoffset;
pp->uap_objsize = objsize;
pp->uap_cmp = compare_func;
if (flags & UU_AVL_POOL_DEBUG)
pp->uap_debug = 1;
pp->uap_last_index = 0;
(void) pthread_mutex_init(&pp->uap_lock, NULL);
pp->uap_null_avl.ua_next_enc = UU_PTR_ENCODE(&pp->uap_null_avl);
pp->uap_null_avl.ua_prev_enc = UU_PTR_ENCODE(&pp->uap_null_avl);
(void) pthread_mutex_lock(&uu_apool_list_lock);
pp->uap_next = next = &uu_null_apool;
pp->uap_prev = prev = next->uap_prev;
next->uap_prev = pp;
prev->uap_next = pp;
(void) pthread_mutex_unlock(&uu_apool_list_lock);
return (pp);
}
void
uu_avl_pool_destroy(uu_avl_pool_t *pp)
{
if (pp->uap_debug) {
if (pp->uap_null_avl.ua_next_enc !=
UU_PTR_ENCODE(&pp->uap_null_avl) ||
pp->uap_null_avl.ua_prev_enc !=
UU_PTR_ENCODE(&pp->uap_null_avl)) {
uu_panic("uu_avl_pool_destroy: Pool \"%.*s\" (%p) has "
"outstanding avls, or is corrupt.\n",
(int)sizeof (pp->uap_name), pp->uap_name,
(void *)pp);
}
}
(void) pthread_mutex_lock(&uu_apool_list_lock);
pp->uap_next->uap_prev = pp->uap_prev;
pp->uap_prev->uap_next = pp->uap_next;
(void) pthread_mutex_unlock(&uu_apool_list_lock);
pp->uap_prev = NULL;
pp->uap_next = NULL;
uu_free(pp);
}
void
uu_avl_node_init(void *base, uu_avl_node_t *np, uu_avl_pool_t *pp)
{
uintptr_t *na = (uintptr_t *)np;
if (pp->uap_debug) {
uintptr_t offset = (uintptr_t)np - (uintptr_t)base;
if (offset + sizeof (*np) > pp->uap_objsize) {
uu_panic("uu_avl_node_init(%p, %p, %p (\"%s\")): "
"offset %ld doesn't fit in object (size %ld)\n",
base, (void *)np, (void *)pp, pp->uap_name,
(long)offset, (long)pp->uap_objsize);
}
if (offset != pp->uap_nodeoffset) {
uu_panic("uu_avl_node_init(%p, %p, %p (\"%s\")): "
"offset %ld doesn't match pool's offset (%ld)\n",
base, (void *)np, (void *)pp, pp->uap_name,
(long)offset, (long)pp->uap_objsize);
}
}
na[0] = POOL_TO_MARKER(pp);
na[1] = 0;
}
void
uu_avl_node_fini(void *base, uu_avl_node_t *np, uu_avl_pool_t *pp)
{
uintptr_t *na = (uintptr_t *)np;
if (pp->uap_debug) {
if (na[0] == DEAD_MARKER && na[1] == DEAD_MARKER) {
uu_panic("uu_avl_node_fini(%p, %p, %p (\"%s\")): "
"node already finied\n",
base, (void *)np, (void *)pp, pp->uap_name);
}
if (na[0] != POOL_TO_MARKER(pp) || na[1] != 0) {
uu_panic("uu_avl_node_fini(%p, %p, %p (\"%s\")): "
"node corrupt, in tree, or in different pool\n",
base, (void *)np, (void *)pp, pp->uap_name);
}
}
na[0] = DEAD_MARKER;
na[1] = DEAD_MARKER;
na[2] = DEAD_MARKER;
}
struct uu_avl_node_compare_info {
uu_compare_fn_t *ac_compare;
void *ac_private;
void *ac_right;
void *ac_found;
};
static int
uu_avl_node_compare(const void *l, const void *r)
{
struct uu_avl_node_compare_info *info =
(struct uu_avl_node_compare_info *)l;
int res = info->ac_compare(r, info->ac_right, info->ac_private);
if (res == 0) {
if (info->ac_found == NULL)
info->ac_found = (void *)r;
return (-1);
}
if (res < 0)
return (1);
return (-1);
}
uu_avl_t *
uu_avl_create(uu_avl_pool_t *pp, void *parent, uint32_t flags)
{
uu_avl_t *ap, *next, *prev;
if (flags & ~UU_AVL_DEBUG) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
ap = uu_zalloc(sizeof (*ap));
if (ap == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
ap->ua_pool = pp;
ap->ua_parent_enc = UU_PTR_ENCODE(parent);
ap->ua_debug = pp->uap_debug || (flags & UU_AVL_DEBUG);
ap->ua_index = (pp->uap_last_index = INDEX_NEXT(pp->uap_last_index));
avl_create(&ap->ua_tree, &uu_avl_node_compare, pp->uap_objsize,
pp->uap_nodeoffset);
ap->ua_null_walk.uaw_next = &ap->ua_null_walk;
ap->ua_null_walk.uaw_prev = &ap->ua_null_walk;
(void) pthread_mutex_lock(&pp->uap_lock);
next = &pp->uap_null_avl;
prev = UU_PTR_DECODE(next->ua_prev_enc);
ap->ua_next_enc = UU_PTR_ENCODE(next);
ap->ua_prev_enc = UU_PTR_ENCODE(prev);
next->ua_prev_enc = UU_PTR_ENCODE(ap);
prev->ua_next_enc = UU_PTR_ENCODE(ap);
(void) pthread_mutex_unlock(&pp->uap_lock);
return (ap);
}
void
uu_avl_destroy(uu_avl_t *ap)
{
uu_avl_pool_t *pp = ap->ua_pool;
if (ap->ua_debug) {
if (avl_numnodes(&ap->ua_tree) != 0) {
uu_panic("uu_avl_destroy(%p): tree not empty\n",
(void *)ap);
}
if (ap->ua_null_walk.uaw_next != &ap->ua_null_walk ||
ap->ua_null_walk.uaw_prev != &ap->ua_null_walk) {
uu_panic("uu_avl_destroy(%p): outstanding walkers\n",
(void *)ap);
}
}
(void) pthread_mutex_lock(&pp->uap_lock);
UU_AVL_PTR(ap->ua_next_enc)->ua_prev_enc = ap->ua_prev_enc;
UU_AVL_PTR(ap->ua_prev_enc)->ua_next_enc = ap->ua_next_enc;
(void) pthread_mutex_unlock(&pp->uap_lock);
ap->ua_prev_enc = UU_PTR_ENCODE(NULL);
ap->ua_next_enc = UU_PTR_ENCODE(NULL);
ap->ua_pool = NULL;
avl_destroy(&ap->ua_tree);
uu_free(ap);
}
size_t
uu_avl_numnodes(uu_avl_t *ap)
{
return (avl_numnodes(&ap->ua_tree));
}
void *
uu_avl_first(uu_avl_t *ap)
{
return (avl_first(&ap->ua_tree));
}
void *
uu_avl_last(uu_avl_t *ap)
{
return (avl_last(&ap->ua_tree));
}
void *
uu_avl_next(uu_avl_t *ap, void *node)
{
return (AVL_NEXT(&ap->ua_tree, node));
}
void *
uu_avl_prev(uu_avl_t *ap, void *node)
{
return (AVL_PREV(&ap->ua_tree, node));
}
static void
_avl_walk_init(uu_avl_walk_t *wp, uu_avl_t *ap, uint32_t flags)
{
uu_avl_walk_t *next, *prev;
int robust = (flags & UU_WALK_ROBUST);
int direction = (flags & UU_WALK_REVERSE)? -1 : 1;
(void) memset(wp, 0, sizeof (*wp));
wp->uaw_avl = ap;
wp->uaw_robust = robust;
wp->uaw_dir = direction;
if (direction > 0)
wp->uaw_next_result = avl_first(&ap->ua_tree);
else
wp->uaw_next_result = avl_last(&ap->ua_tree);
if (ap->ua_debug || robust) {
wp->uaw_next = next = &ap->ua_null_walk;
wp->uaw_prev = prev = next->uaw_prev;
next->uaw_prev = wp;
prev->uaw_next = wp;
}
}
static void *
_avl_walk_advance(uu_avl_walk_t *wp, uu_avl_t *ap)
{
void *np = wp->uaw_next_result;
avl_tree_t *t = &ap->ua_tree;
if (np == NULL)
return (NULL);
wp->uaw_next_result = (wp->uaw_dir > 0)? AVL_NEXT(t, np) :
AVL_PREV(t, np);
return (np);
}
static void
_avl_walk_fini(uu_avl_walk_t *wp)
{
if (wp->uaw_next != NULL) {
wp->uaw_next->uaw_prev = wp->uaw_prev;
wp->uaw_prev->uaw_next = wp->uaw_next;
wp->uaw_next = NULL;
wp->uaw_prev = NULL;
}
wp->uaw_avl = NULL;
wp->uaw_next_result = NULL;
}
uu_avl_walk_t *
uu_avl_walk_start(uu_avl_t *ap, uint32_t flags)
{
uu_avl_walk_t *wp;
if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
wp = uu_zalloc(sizeof (*wp));
if (wp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
_avl_walk_init(wp, ap, flags);
return (wp);
}
void *
uu_avl_walk_next(uu_avl_walk_t *wp)
{
return (_avl_walk_advance(wp, wp->uaw_avl));
}
void
uu_avl_walk_end(uu_avl_walk_t *wp)
{
_avl_walk_fini(wp);
uu_free(wp);
}
int
uu_avl_walk(uu_avl_t *ap, uu_walk_fn_t *func, void *private, uint32_t flags)
{
void *e;
uu_avl_walk_t my_walk;
int status = UU_WALK_NEXT;
if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (-1);
}
_avl_walk_init(&my_walk, ap, flags);
while (status == UU_WALK_NEXT &&
(e = _avl_walk_advance(&my_walk, ap)) != NULL)
status = (*func)(e, private);
_avl_walk_fini(&my_walk);
if (status >= 0)
return (0);
uu_set_error(UU_ERROR_CALLBACK_FAILED);
return (-1);
}
void
uu_avl_remove(uu_avl_t *ap, void *elem)
{
uu_avl_walk_t *wp;
uu_avl_pool_t *pp = ap->ua_pool;
uintptr_t *na = NODE_ARRAY(pp, elem);
if (ap->ua_debug) {
/*
* invalidate outstanding uu_avl_index_ts.
*/
ap->ua_index = INDEX_NEXT(ap->ua_index);
}
/*
* Robust walkers most be advanced, if we are removing the node
* they are currently using. In debug mode, non-robust walkers
* are also on the walker list.
*/
for (wp = ap->ua_null_walk.uaw_next; wp != &ap->ua_null_walk;
wp = wp->uaw_next) {
if (wp->uaw_robust) {
if (elem == wp->uaw_next_result)
(void) _avl_walk_advance(wp, ap);
} else if (wp->uaw_next_result != NULL) {
uu_panic("uu_avl_remove(%p, %p): active non-robust "
"walker\n", (void *)ap, elem);
}
}
avl_remove(&ap->ua_tree, elem);
na[0] = POOL_TO_MARKER(pp);
na[1] = 0;
}
void *
uu_avl_teardown(uu_avl_t *ap, void **cookie)
{
void *elem = avl_destroy_nodes(&ap->ua_tree, cookie);
if (elem != NULL) {
uu_avl_pool_t *pp = ap->ua_pool;
uintptr_t *na = NODE_ARRAY(pp, elem);
na[0] = POOL_TO_MARKER(pp);
na[1] = 0;
}
return (elem);
}
void *
uu_avl_find(uu_avl_t *ap, void *elem, void *private, uu_avl_index_t *out)
{
struct uu_avl_node_compare_info info;
void *result;
info.ac_compare = ap->ua_pool->uap_cmp;
info.ac_private = private;
info.ac_right = elem;
info.ac_found = NULL;
result = avl_find(&ap->ua_tree, &info, out);
if (out != NULL)
*out = INDEX_ENCODE(ap, *out);
if (ap->ua_debug && result != NULL)
uu_panic("uu_avl_find: internal error: avl_find succeeded\n");
return (info.ac_found);
}
void
uu_avl_insert(uu_avl_t *ap, void *elem, uu_avl_index_t idx)
{
if (ap->ua_debug) {
uu_avl_pool_t *pp = ap->ua_pool;
uintptr_t *na = NODE_ARRAY(pp, elem);
if (na[1] != 0)
uu_panic("uu_avl_insert(%p, %p, %p): node already "
"in tree, or corrupt\n",
(void *)ap, elem, (void *)idx);
if (na[0] == 0)
uu_panic("uu_avl_insert(%p, %p, %p): node not "
"initialized\n",
(void *)ap, elem, (void *)idx);
if (na[0] != POOL_TO_MARKER(pp))
uu_panic("uu_avl_insert(%p, %p, %p): node from "
"other pool, or corrupt\n",
(void *)ap, elem, (void *)idx);
if (!INDEX_VALID(ap, idx))
uu_panic("uu_avl_insert(%p, %p, %p): %s\n",
(void *)ap, elem, (void *)idx,
INDEX_CHECK(idx)? "outdated index" :
"invalid index");
/*
* invalidate outstanding uu_avl_index_ts.
*/
ap->ua_index = INDEX_NEXT(ap->ua_index);
}
avl_insert(&ap->ua_tree, elem, INDEX_DECODE(idx));
}
void *
uu_avl_nearest_next(uu_avl_t *ap, uu_avl_index_t idx)
{
if (ap->ua_debug && !INDEX_VALID(ap, idx))
uu_panic("uu_avl_nearest_next(%p, %p): %s\n",
(void *)ap, (void *)idx, INDEX_CHECK(idx)?
"outdated index" : "invalid index");
return (avl_nearest(&ap->ua_tree, INDEX_DECODE(idx), AVL_AFTER));
}
void *
uu_avl_nearest_prev(uu_avl_t *ap, uu_avl_index_t idx)
{
if (ap->ua_debug && !INDEX_VALID(ap, idx))
uu_panic("uu_avl_nearest_prev(%p, %p): %s\n",
(void *)ap, (void *)idx, INDEX_CHECK(idx)?
"outdated index" : "invalid index");
return (avl_nearest(&ap->ua_tree, INDEX_DECODE(idx), AVL_BEFORE));
}
/*
* called from uu_lockup() and uu_release(), as part of our fork1()-safety.
*/
void
uu_avl_lockup(void)
{
uu_avl_pool_t *pp;
(void) pthread_mutex_lock(&uu_apool_list_lock);
for (pp = uu_null_apool.uap_next; pp != &uu_null_apool;
pp = pp->uap_next)
(void) pthread_mutex_lock(&pp->uap_lock);
}
void
uu_avl_release(void)
{
uu_avl_pool_t *pp;
for (pp = uu_null_apool.uap_next; pp != &uu_null_apool;
pp = pp->uap_next)
(void) pthread_mutex_unlock(&pp->uap_lock);
(void) pthread_mutex_unlock(&uu_apool_list_lock);
}