zfs-builds-mm/zfs-0.8.5/lib/libuutil/uu_list.c

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2020-10-22 13:48:46 +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/time.h>
#define ELEM_TO_NODE(lp, e) \
((uu_list_node_impl_t *)((uintptr_t)(e) + (lp)->ul_offset))
#define NODE_TO_ELEM(lp, n) \
((void *)((uintptr_t)(n) - (lp)->ul_offset))
/*
* uu_list_index_ts define a location for insertion. They are simply a
* pointer to the object after the insertion point. We store a mark
* in the low-bits of the index, to help prevent mistakes.
*
* When debugging, the index mark changes on every insert and delete, to
* catch stale references.
*/
#define INDEX_MAX (sizeof (uintptr_t) - 1)
#define INDEX_NEXT(m) (((m) == INDEX_MAX)? 1 : ((m) + 1) & INDEX_MAX)
#define INDEX_TO_NODE(i) ((uu_list_node_impl_t *)((i) & ~INDEX_MAX))
#define NODE_TO_INDEX(p, n) (((uintptr_t)(n) & ~INDEX_MAX) | (p)->ul_index)
#define INDEX_VALID(p, i) (((i) & INDEX_MAX) == (p)->ul_index)
#define INDEX_CHECK(i) (((i) & INDEX_MAX) != 0)
#define POOL_TO_MARKER(pp) ((void *)((uintptr_t)(pp) | 1))
static uu_list_pool_t uu_null_lpool = { &uu_null_lpool, &uu_null_lpool };
static pthread_mutex_t uu_lpool_list_lock = PTHREAD_MUTEX_INITIALIZER;
uu_list_pool_t *
uu_list_pool_create(const char *name, size_t objsize,
size_t nodeoffset, uu_compare_fn_t *compare_func, uint32_t flags)
{
uu_list_pool_t *pp, *next, *prev;
if (name == NULL ||
uu_check_name(name, UU_NAME_DOMAIN) == -1 ||
nodeoffset + sizeof (uu_list_node_t) > objsize) {
uu_set_error(UU_ERROR_INVALID_ARGUMENT);
return (NULL);
}
if (flags & ~UU_LIST_POOL_DEBUG) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
pp = uu_zalloc(sizeof (uu_list_pool_t));
if (pp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
(void) strlcpy(pp->ulp_name, name, sizeof (pp->ulp_name));
pp->ulp_nodeoffset = nodeoffset;
pp->ulp_objsize = objsize;
pp->ulp_cmp = compare_func;
if (flags & UU_LIST_POOL_DEBUG)
pp->ulp_debug = 1;
pp->ulp_last_index = 0;
(void) pthread_mutex_init(&pp->ulp_lock, NULL);
pp->ulp_null_list.ul_next_enc = UU_PTR_ENCODE(&pp->ulp_null_list);
pp->ulp_null_list.ul_prev_enc = UU_PTR_ENCODE(&pp->ulp_null_list);
(void) pthread_mutex_lock(&uu_lpool_list_lock);
pp->ulp_next = next = &uu_null_lpool;
pp->ulp_prev = prev = next->ulp_prev;
next->ulp_prev = pp;
prev->ulp_next = pp;
(void) pthread_mutex_unlock(&uu_lpool_list_lock);
return (pp);
}
void
uu_list_pool_destroy(uu_list_pool_t *pp)
{
if (pp->ulp_debug) {
if (pp->ulp_null_list.ul_next_enc !=
UU_PTR_ENCODE(&pp->ulp_null_list) ||
pp->ulp_null_list.ul_prev_enc !=
UU_PTR_ENCODE(&pp->ulp_null_list)) {
uu_panic("uu_list_pool_destroy: Pool \"%.*s\" (%p) has "
"outstanding lists, or is corrupt.\n",
(int)sizeof (pp->ulp_name), pp->ulp_name,
(void *)pp);
}
}
(void) pthread_mutex_lock(&uu_lpool_list_lock);
pp->ulp_next->ulp_prev = pp->ulp_prev;
pp->ulp_prev->ulp_next = pp->ulp_next;
(void) pthread_mutex_unlock(&uu_lpool_list_lock);
pp->ulp_prev = NULL;
pp->ulp_next = NULL;
uu_free(pp);
}
void
uu_list_node_init(void *base, uu_list_node_t *np_arg, uu_list_pool_t *pp)
{
uu_list_node_impl_t *np = (uu_list_node_impl_t *)np_arg;
if (pp->ulp_debug) {
uintptr_t offset = (uintptr_t)np - (uintptr_t)base;
if (offset + sizeof (*np) > pp->ulp_objsize) {
uu_panic("uu_list_node_init(%p, %p, %p (\"%s\")): "
"offset %ld doesn't fit in object (size %ld)\n",
base, (void *)np, (void *)pp, pp->ulp_name,
(long)offset, (long)pp->ulp_objsize);
}
if (offset != pp->ulp_nodeoffset) {
uu_panic("uu_list_node_init(%p, %p, %p (\"%s\")): "
"offset %ld doesn't match pool's offset (%ld)\n",
base, (void *)np, (void *)pp, pp->ulp_name,
(long)offset, (long)pp->ulp_objsize);
}
}
np->uln_next = POOL_TO_MARKER(pp);
np->uln_prev = NULL;
}
void
uu_list_node_fini(void *base, uu_list_node_t *np_arg, uu_list_pool_t *pp)
{
uu_list_node_impl_t *np = (uu_list_node_impl_t *)np_arg;
if (pp->ulp_debug) {
if (np->uln_next == NULL &&
np->uln_prev == NULL) {
uu_panic("uu_list_node_fini(%p, %p, %p (\"%s\")): "
"node already finied\n",
base, (void *)np_arg, (void *)pp, pp->ulp_name);
}
if (np->uln_next != POOL_TO_MARKER(pp) ||
np->uln_prev != NULL) {
uu_panic("uu_list_node_fini(%p, %p, %p (\"%s\")): "
"node corrupt or on list\n",
base, (void *)np_arg, (void *)pp, pp->ulp_name);
}
}
np->uln_next = NULL;
np->uln_prev = NULL;
}
uu_list_t *
uu_list_create(uu_list_pool_t *pp, void *parent, uint32_t flags)
{
uu_list_t *lp, *next, *prev;
if (flags & ~(UU_LIST_DEBUG | UU_LIST_SORTED)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
if ((flags & UU_LIST_SORTED) && pp->ulp_cmp == NULL) {
if (pp->ulp_debug)
uu_panic("uu_list_create(%p, ...): requested "
"UU_LIST_SORTED, but pool has no comparison func\n",
(void *)pp);
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (NULL);
}
lp = uu_zalloc(sizeof (*lp));
if (lp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
lp->ul_pool = pp;
lp->ul_parent_enc = UU_PTR_ENCODE(parent);
lp->ul_offset = pp->ulp_nodeoffset;
lp->ul_debug = pp->ulp_debug || (flags & UU_LIST_DEBUG);
lp->ul_sorted = (flags & UU_LIST_SORTED);
lp->ul_numnodes = 0;
lp->ul_index = (pp->ulp_last_index = INDEX_NEXT(pp->ulp_last_index));
lp->ul_null_node.uln_next = &lp->ul_null_node;
lp->ul_null_node.uln_prev = &lp->ul_null_node;
lp->ul_null_walk.ulw_next = &lp->ul_null_walk;
lp->ul_null_walk.ulw_prev = &lp->ul_null_walk;
(void) pthread_mutex_lock(&pp->ulp_lock);
next = &pp->ulp_null_list;
prev = UU_PTR_DECODE(next->ul_prev_enc);
lp->ul_next_enc = UU_PTR_ENCODE(next);
lp->ul_prev_enc = UU_PTR_ENCODE(prev);
next->ul_prev_enc = UU_PTR_ENCODE(lp);
prev->ul_next_enc = UU_PTR_ENCODE(lp);
(void) pthread_mutex_unlock(&pp->ulp_lock);
return (lp);
}
void
uu_list_destroy(uu_list_t *lp)
{
uu_list_pool_t *pp = lp->ul_pool;
if (lp->ul_debug) {
if (lp->ul_null_node.uln_next != &lp->ul_null_node ||
lp->ul_null_node.uln_prev != &lp->ul_null_node) {
uu_panic("uu_list_destroy(%p): list not empty\n",
(void *)lp);
}
if (lp->ul_numnodes != 0) {
uu_panic("uu_list_destroy(%p): numnodes is nonzero, "
"but list is empty\n", (void *)lp);
}
if (lp->ul_null_walk.ulw_next != &lp->ul_null_walk ||
lp->ul_null_walk.ulw_prev != &lp->ul_null_walk) {
uu_panic("uu_list_destroy(%p): outstanding walkers\n",
(void *)lp);
}
}
(void) pthread_mutex_lock(&pp->ulp_lock);
UU_LIST_PTR(lp->ul_next_enc)->ul_prev_enc = lp->ul_prev_enc;
UU_LIST_PTR(lp->ul_prev_enc)->ul_next_enc = lp->ul_next_enc;
(void) pthread_mutex_unlock(&pp->ulp_lock);
lp->ul_prev_enc = UU_PTR_ENCODE(NULL);
lp->ul_next_enc = UU_PTR_ENCODE(NULL);
lp->ul_pool = NULL;
uu_free(lp);
}
static void
list_insert(uu_list_t *lp, uu_list_node_impl_t *np, uu_list_node_impl_t *prev,
uu_list_node_impl_t *next)
{
if (lp->ul_debug) {
if (next->uln_prev != prev || prev->uln_next != next)
uu_panic("insert(%p): internal error: %p and %p not "
"neighbors\n", (void *)lp, (void *)next,
(void *)prev);
if (np->uln_next != POOL_TO_MARKER(lp->ul_pool) ||
np->uln_prev != NULL) {
uu_panic("insert(%p): elem %p node %p corrupt, "
"not initialized, or already in a list.\n",
(void *)lp, NODE_TO_ELEM(lp, np), (void *)np);
}
/*
* invalidate outstanding uu_list_index_ts.
*/
lp->ul_index = INDEX_NEXT(lp->ul_index);
}
np->uln_next = next;
np->uln_prev = prev;
next->uln_prev = np;
prev->uln_next = np;
lp->ul_numnodes++;
}
void
uu_list_insert(uu_list_t *lp, void *elem, uu_list_index_t idx)
{
uu_list_node_impl_t *np;
np = INDEX_TO_NODE(idx);
if (np == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (!INDEX_VALID(lp, idx))
uu_panic("uu_list_insert(%p, %p, %p): %s\n",
(void *)lp, elem, (void *)idx,
INDEX_CHECK(idx)? "outdated index" :
"invalid index");
if (np->uln_prev == NULL)
uu_panic("uu_list_insert(%p, %p, %p): out-of-date "
"index\n", (void *)lp, elem, (void *)idx);
}
list_insert(lp, ELEM_TO_NODE(lp, elem), np->uln_prev, np);
}
void *
uu_list_find(uu_list_t *lp, void *elem, void *private, uu_list_index_t *out)
{
int sorted = lp->ul_sorted;
uu_compare_fn_t *func = lp->ul_pool->ulp_cmp;
uu_list_node_impl_t *np;
if (func == NULL) {
if (out != NULL)
*out = 0;
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (NULL);
}
for (np = lp->ul_null_node.uln_next; np != &lp->ul_null_node;
np = np->uln_next) {
void *ep = NODE_TO_ELEM(lp, np);
int cmp = func(ep, elem, private);
if (cmp == 0) {
if (out != NULL)
*out = NODE_TO_INDEX(lp, np);
return (ep);
}
if (sorted && cmp > 0) {
if (out != NULL)
*out = NODE_TO_INDEX(lp, np);
return (NULL);
}
}
if (out != NULL)
*out = NODE_TO_INDEX(lp, 0);
return (NULL);
}
void *
uu_list_nearest_next(uu_list_t *lp, uu_list_index_t idx)
{
uu_list_node_impl_t *np = INDEX_TO_NODE(idx);
if (np == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (!INDEX_VALID(lp, idx))
uu_panic("uu_list_nearest_next(%p, %p): %s\n",
(void *)lp, (void *)idx,
INDEX_CHECK(idx)? "outdated index" :
"invalid index");
if (np->uln_prev == NULL)
uu_panic("uu_list_nearest_next(%p, %p): out-of-date "
"index\n", (void *)lp, (void *)idx);
}
if (np == &lp->ul_null_node)
return (NULL);
else
return (NODE_TO_ELEM(lp, np));
}
void *
uu_list_nearest_prev(uu_list_t *lp, uu_list_index_t idx)
{
uu_list_node_impl_t *np = INDEX_TO_NODE(idx);
if (np == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (!INDEX_VALID(lp, idx))
uu_panic("uu_list_nearest_prev(%p, %p): %s\n",
(void *)lp, (void *)idx, INDEX_CHECK(idx)?
"outdated index" : "invalid index");
if (np->uln_prev == NULL)
uu_panic("uu_list_nearest_prev(%p, %p): out-of-date "
"index\n", (void *)lp, (void *)idx);
}
if ((np = np->uln_prev) == &lp->ul_null_node)
return (NULL);
else
return (NODE_TO_ELEM(lp, np));
}
static void
list_walk_init(uu_list_walk_t *wp, uu_list_t *lp, uint32_t flags)
{
uu_list_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->ulw_list = lp;
wp->ulw_robust = robust;
wp->ulw_dir = direction;
if (direction > 0)
wp->ulw_next_result = lp->ul_null_node.uln_next;
else
wp->ulw_next_result = lp->ul_null_node.uln_prev;
if (lp->ul_debug || robust) {
/*
* Add this walker to the list's list of walkers so
* uu_list_remove() can advance us if somebody tries to
* remove ulw_next_result.
*/
wp->ulw_next = next = &lp->ul_null_walk;
wp->ulw_prev = prev = next->ulw_prev;
next->ulw_prev = wp;
prev->ulw_next = wp;
}
}
static uu_list_node_impl_t *
list_walk_advance(uu_list_walk_t *wp, uu_list_t *lp)
{
uu_list_node_impl_t *np = wp->ulw_next_result;
uu_list_node_impl_t *next;
if (np == &lp->ul_null_node)
return (NULL);
next = (wp->ulw_dir > 0)? np->uln_next : np->uln_prev;
wp->ulw_next_result = next;
return (np);
}
static void
list_walk_fini(uu_list_walk_t *wp)
{
/* GLXXX debugging? */
if (wp->ulw_next != NULL) {
wp->ulw_next->ulw_prev = wp->ulw_prev;
wp->ulw_prev->ulw_next = wp->ulw_next;
wp->ulw_next = NULL;
wp->ulw_prev = NULL;
}
wp->ulw_list = NULL;
wp->ulw_next_result = NULL;
}
uu_list_walk_t *
uu_list_walk_start(uu_list_t *lp, uint32_t flags)
{
uu_list_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);
}
list_walk_init(wp, lp, flags);
return (wp);
}
void *
uu_list_walk_next(uu_list_walk_t *wp)
{
uu_list_t *lp = wp->ulw_list;
uu_list_node_impl_t *np = list_walk_advance(wp, lp);
if (np == NULL)
return (NULL);
return (NODE_TO_ELEM(lp, np));
}
void
uu_list_walk_end(uu_list_walk_t *wp)
{
list_walk_fini(wp);
uu_free(wp);
}
int
uu_list_walk(uu_list_t *lp, uu_walk_fn_t *func, void *private, uint32_t flags)
{
uu_list_node_impl_t *np;
int status = UU_WALK_NEXT;
int robust = (flags & UU_WALK_ROBUST);
int reverse = (flags & UU_WALK_REVERSE);
if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (-1);
}
if (lp->ul_debug || robust) {
uu_list_walk_t my_walk;
void *e;
list_walk_init(&my_walk, lp, flags);
while (status == UU_WALK_NEXT &&
(e = uu_list_walk_next(&my_walk)) != NULL)
status = (*func)(e, private);
list_walk_fini(&my_walk);
} else {
if (!reverse) {
for (np = lp->ul_null_node.uln_next;
status == UU_WALK_NEXT && np != &lp->ul_null_node;
np = np->uln_next) {
status = (*func)(NODE_TO_ELEM(lp, np), private);
}
} else {
for (np = lp->ul_null_node.uln_prev;
status == UU_WALK_NEXT && np != &lp->ul_null_node;
np = np->uln_prev) {
status = (*func)(NODE_TO_ELEM(lp, np), private);
}
}
}
if (status >= 0)
return (0);
uu_set_error(UU_ERROR_CALLBACK_FAILED);
return (-1);
}
void
uu_list_remove(uu_list_t *lp, void *elem)
{
uu_list_node_impl_t *np = ELEM_TO_NODE(lp, elem);
uu_list_walk_t *wp;
if (lp->ul_debug) {
if (np->uln_prev == NULL)
uu_panic("uu_list_remove(%p, %p): elem not on list\n",
(void *)lp, elem);
/*
* invalidate outstanding uu_list_index_ts.
*/
lp->ul_index = INDEX_NEXT(lp->ul_index);
}
/*
* robust walkers must be advanced. In debug mode, non-robust
* walkers are also on the list. If there are any, it's an error.
*/
for (wp = lp->ul_null_walk.ulw_next; wp != &lp->ul_null_walk;
wp = wp->ulw_next) {
if (wp->ulw_robust) {
if (np == wp->ulw_next_result)
(void) list_walk_advance(wp, lp);
} else if (wp->ulw_next_result != NULL) {
uu_panic("uu_list_remove(%p, %p): active non-robust "
"walker\n", (void *)lp, elem);
}
}
np->uln_next->uln_prev = np->uln_prev;
np->uln_prev->uln_next = np->uln_next;
lp->ul_numnodes--;
np->uln_next = POOL_TO_MARKER(lp->ul_pool);
np->uln_prev = NULL;
}
void *
uu_list_teardown(uu_list_t *lp, void **cookie)
{
void *ep;
/*
* XXX: disable list modification until list is empty
*/
if (lp->ul_debug && *cookie != NULL)
uu_panic("uu_list_teardown(%p, %p): unexpected cookie\n",
(void *)lp, (void *)cookie);
ep = uu_list_first(lp);
if (ep)
uu_list_remove(lp, ep);
return (ep);
}
int
uu_list_insert_before(uu_list_t *lp, void *target, void *elem)
{
uu_list_node_impl_t *np = ELEM_TO_NODE(lp, target);
if (target == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (np->uln_prev == NULL)
uu_panic("uu_list_insert_before(%p, %p, %p): %p is "
"not currently on a list\n",
(void *)lp, target, elem, target);
}
if (lp->ul_sorted) {
if (lp->ul_debug)
uu_panic("uu_list_insert_before(%p, ...): list is "
"UU_LIST_SORTED\n", (void *)lp);
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (-1);
}
list_insert(lp, ELEM_TO_NODE(lp, elem), np->uln_prev, np);
return (0);
}
int
uu_list_insert_after(uu_list_t *lp, void *target, void *elem)
{
uu_list_node_impl_t *np = ELEM_TO_NODE(lp, target);
if (target == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (np->uln_prev == NULL)
uu_panic("uu_list_insert_after(%p, %p, %p): %p is "
"not currently on a list\n",
(void *)lp, target, elem, target);
}
if (lp->ul_sorted) {
if (lp->ul_debug)
uu_panic("uu_list_insert_after(%p, ...): list is "
"UU_LIST_SORTED\n", (void *)lp);
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (-1);
}
list_insert(lp, ELEM_TO_NODE(lp, elem), np, np->uln_next);
return (0);
}
size_t
uu_list_numnodes(uu_list_t *lp)
{
return (lp->ul_numnodes);
}
void *
uu_list_first(uu_list_t *lp)
{
uu_list_node_impl_t *n = lp->ul_null_node.uln_next;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
void *
uu_list_last(uu_list_t *lp)
{
uu_list_node_impl_t *n = lp->ul_null_node.uln_prev;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
void *
uu_list_next(uu_list_t *lp, void *elem)
{
uu_list_node_impl_t *n = ELEM_TO_NODE(lp, elem);
n = n->uln_next;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
void *
uu_list_prev(uu_list_t *lp, void *elem)
{
uu_list_node_impl_t *n = ELEM_TO_NODE(lp, elem);
n = n->uln_prev;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
/*
* called from uu_lockup() and uu_release(), as part of our fork1()-safety.
*/
void
uu_list_lockup(void)
{
uu_list_pool_t *pp;
(void) pthread_mutex_lock(&uu_lpool_list_lock);
for (pp = uu_null_lpool.ulp_next; pp != &uu_null_lpool;
pp = pp->ulp_next)
(void) pthread_mutex_lock(&pp->ulp_lock);
}
void
uu_list_release(void)
{
uu_list_pool_t *pp;
for (pp = uu_null_lpool.ulp_next; pp != &uu_null_lpool;
pp = pp->ulp_next)
(void) pthread_mutex_unlock(&pp->ulp_lock);
(void) pthread_mutex_unlock(&uu_lpool_list_lock);
}