cddl/contrib/opensolaris/lib/libuutil/common/uu_list.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "libuutil_common.h"
  30
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34 #include <sys/time.h>
  35
  36 #define ELEM_TO_NODE(lp, e) \
  37         ((uu_list_node_impl_t *)((uintptr_t)(e) + (lp)->ul_offset))
  38
  39 #define NODE_TO_ELEM(lp, n) \
  40         ((void *)((uintptr_t)(n) - (lp)->ul_offset))
  41
  42 /*
  43  * uu_list_index_ts define a location for insertion.  They are simply a
  44  * pointer to the object after the insertion point.  We store a mark
  45  * in the low-bits of the index, to help prevent mistakes.
  46  *
  47  * When debugging, the index mark changes on every insert and delete, to
  48  * catch stale references.
  49  */
  50 #define INDEX_MAX               (sizeof (uintptr_t) - 1)
  51 #define INDEX_NEXT(m)           (((m) == INDEX_MAX)? 1 : ((m) + 1) & INDEX_MAX)
  52
  53 #define INDEX_TO_NODE(i)        ((uu_list_node_impl_t *)((i) & ~INDEX_MAX))
  54 #define NODE_TO_INDEX(p, n)     (((uintptr_t)(n) & ~INDEX_MAX) | (p)->ul_index)
  55 #define INDEX_VALID(p, i)       (((i) & INDEX_MAX) == (p)->ul_index)
  56 #define INDEX_CHECK(i)          (((i) & INDEX_MAX) != 0)
  57
  58 #define POOL_TO_MARKER(pp) ((void *)((uintptr_t)(pp) | 1))
  59
  60 static uu_list_pool_t   uu_null_lpool = { &uu_null_lpool, &uu_null_lpool };
  61 static pthread_mutex_t  uu_lpool_list_lock = PTHREAD_MUTEX_INITIALIZER;
  62
  63 uu_list_pool_t *
  64 uu_list_pool_create(const char *name, size_t objsize,
  65     size_t nodeoffset, uu_compare_fn_t *compare_func, uint32_t flags)
  66 {
  67         uu_list_pool_t *pp, *next, *prev;
  68
  69         if (name == NULL ||
  70             uu_check_name(name, UU_NAME_DOMAIN) == -1 ||
  71             nodeoffset + sizeof (uu_list_node_t) > objsize) {
  72                 uu_set_error(UU_ERROR_INVALID_ARGUMENT);
  73                 return (NULL);
  74         }
  75
  76         if (flags & ~UU_LIST_POOL_DEBUG) {
  77                 uu_set_error(UU_ERROR_UNKNOWN_FLAG);
  78                 return (NULL);
  79         }
  80
  81         pp = uu_zalloc(sizeof (uu_list_pool_t));
  82         if (pp == NULL) {
  83                 uu_set_error(UU_ERROR_NO_MEMORY);
  84                 return (NULL);
  85         }
  86
  87         (void) strlcpy(pp->ulp_name, name, sizeof (pp->ulp_name));
  88         pp->ulp_nodeoffset = nodeoffset;
  89         pp->ulp_objsize = objsize;
  90         pp->ulp_cmp = compare_func;
  91         if (flags & UU_LIST_POOL_DEBUG)
  92                 pp->ulp_debug = 1;
  93         pp->ulp_last_index = 0;
  94
  95         (void) pthread_mutex_init(&pp->ulp_lock, NULL);
  96
  97         pp->ulp_null_list.ul_next_enc = UU_PTR_ENCODE(&pp->ulp_null_list);
  98         pp->ulp_null_list.ul_prev_enc = UU_PTR_ENCODE(&pp->ulp_null_list);
  99
 100         (void) pthread_mutex_lock(&uu_lpool_list_lock);
 101         pp->ulp_next = next = &uu_null_lpool;
 102         pp->ulp_prev = prev = next->ulp_prev;
 103         next->ulp_prev = pp;
 104         prev->ulp_next = pp;
 105         (void) pthread_mutex_unlock(&uu_lpool_list_lock);
 106
 107         return (pp);
 108 }
 109
 110 void
 111 uu_list_pool_destroy(uu_list_pool_t *pp)
 112 {
 113         if (pp->ulp_debug) {
 114                 if (pp->ulp_null_list.ul_next_enc !=
 115                     UU_PTR_ENCODE(&pp->ulp_null_list) ||
 116                     pp->ulp_null_list.ul_prev_enc !=
 117                     UU_PTR_ENCODE(&pp->ulp_null_list)) {
 118                         uu_panic("uu_list_pool_destroy: Pool \"%.*s\" (%p) has "
 119                             "outstanding lists, or is corrupt.\n",
 120                             sizeof (pp->ulp_name), pp->ulp_name, pp);
 121                 }
 122         }
 123         (void) pthread_mutex_lock(&uu_lpool_list_lock);
 124         pp->ulp_next->ulp_prev = pp->ulp_prev;
 125         pp->ulp_prev->ulp_next = pp->ulp_next;
 126         (void) pthread_mutex_unlock(&uu_lpool_list_lock);
 127         pp->ulp_prev = NULL;
 128         pp->ulp_next = NULL;
 129         uu_free(pp);
 130 }
 131
 132 void
 133 uu_list_node_init(void *base, uu_list_node_t *np_arg, uu_list_pool_t *pp)
 134 {
 135         uu_list_node_impl_t *np = (uu_list_node_impl_t *)np_arg;
 136
 137         if (pp->ulp_debug) {
 138                 uintptr_t offset = (uintptr_t)np - (uintptr_t)base;
 139                 if (offset + sizeof (*np) > pp->ulp_objsize) {
 140                         uu_panic("uu_list_node_init(%p, %p, %p (\"%s\")): "
 141                             "offset %ld doesn't fit in object (size %ld)\n",
 142                             base, np, pp, pp->ulp_name, offset,
 143                             pp->ulp_objsize);
 144                 }
 145                 if (offset != pp->ulp_nodeoffset) {
 146                         uu_panic("uu_list_node_init(%p, %p, %p (\"%s\")): "
 147                             "offset %ld doesn't match pool's offset (%ld)\n",
 148                             base, np, pp, pp->ulp_name, offset,
 149                             pp->ulp_objsize);
 150                 }
 151         }
 152         np->uln_next = POOL_TO_MARKER(pp);
 153         np->uln_prev = NULL;
 154 }
 155
 156 void
 157 uu_list_node_fini(void *base, uu_list_node_t *np_arg, uu_list_pool_t *pp)
 158 {
 159         uu_list_node_impl_t *np = (uu_list_node_impl_t *)np_arg;
 160
 161         if (pp->ulp_debug) {
 162                 if (np->uln_next == NULL &&
 163                     np->uln_prev == NULL) {
 164                         uu_panic("uu_list_node_fini(%p, %p, %p (\"%s\")): "
 165                             "node already finied\n",
 166                             base, np_arg, pp, pp->ulp_name);
 167                 }
 168                 if (np->uln_next != POOL_TO_MARKER(pp) ||
 169                     np->uln_prev != NULL) {
 170                         uu_panic("uu_list_node_fini(%p, %p, %p (\"%s\")): "
 171                             "node corrupt or on list\n",
 172                             base, np_arg, pp, pp->ulp_name);
 173                 }
 174         }
 175         np->uln_next = NULL;
 176         np->uln_prev = NULL;
 177 }
 178
 179 uu_list_t *
 180 uu_list_create(uu_list_pool_t *pp, void *parent, uint32_t flags)
 181 {
 182         uu_list_t *lp, *next, *prev;
 183
 184         if (flags & ~(UU_LIST_DEBUG | UU_LIST_SORTED)) {
 185                 uu_set_error(UU_ERROR_UNKNOWN_FLAG);
 186                 return (NULL);
 187         }
 188
 189         if ((flags & UU_LIST_SORTED) && pp->ulp_cmp == NULL) {
 190                 if (pp->ulp_debug)
 191                         uu_panic("uu_list_create(%p, ...): requested "
 192                             "UU_LIST_SORTED, but pool has no comparison func\n",
 193                             pp);
 194                 uu_set_error(UU_ERROR_NOT_SUPPORTED);
 195                 return (NULL);
 196         }
 197
 198         lp = uu_zalloc(sizeof (*lp));
 199         if (lp == NULL) {
 200                 uu_set_error(UU_ERROR_NO_MEMORY);
 201                 return (NULL);
 202         }
 203
 204         lp->ul_pool = pp;
 205         lp->ul_parent_enc = UU_PTR_ENCODE(parent);
 206         lp->ul_offset = pp->ulp_nodeoffset;
 207         lp->ul_debug = pp->ulp_debug || (flags & UU_LIST_DEBUG);
 208         lp->ul_sorted = (flags & UU_LIST_SORTED);
 209         lp->ul_numnodes = 0;
 210         lp->ul_index = (pp->ulp_last_index = INDEX_NEXT(pp->ulp_last_index));
 211
 212         lp->ul_null_node.uln_next = &lp->ul_null_node;
 213         lp->ul_null_node.uln_prev = &lp->ul_null_node;
 214
 215         lp->ul_null_walk.ulw_next = &lp->ul_null_walk;
 216         lp->ul_null_walk.ulw_prev = &lp->ul_null_walk;
 217
 218         (void) pthread_mutex_lock(&pp->ulp_lock);
 219         next = &pp->ulp_null_list;
 220         prev = UU_PTR_DECODE(next->ul_prev_enc);
 221         lp->ul_next_enc = UU_PTR_ENCODE(next);
 222         lp->ul_prev_enc = UU_PTR_ENCODE(prev);
 223         next->ul_prev_enc = UU_PTR_ENCODE(lp);
 224         prev->ul_next_enc = UU_PTR_ENCODE(lp);
 225         (void) pthread_mutex_unlock(&pp->ulp_lock);
 226
 227         return (lp);
 228 }
 229
 230 void
 231 uu_list_destroy(uu_list_t *lp)
 232 {
 233         uu_list_pool_t *pp = lp->ul_pool;
 234
 235         if (lp->ul_debug) {
 236                 if (lp->ul_null_node.uln_next != &lp->ul_null_node ||
 237                     lp->ul_null_node.uln_prev != &lp->ul_null_node) {
 238                         uu_panic("uu_list_destroy(%p):  list not empty\n",
 239                             lp);
 240                 }
 241                 if (lp->ul_numnodes != 0) {
 242                         uu_panic("uu_list_destroy(%p):  numnodes is nonzero, "
 243                             "but list is empty\n", lp);
 244                 }
 245                 if (lp->ul_null_walk.ulw_next != &lp->ul_null_walk ||
 246                     lp->ul_null_walk.ulw_prev != &lp->ul_null_walk) {
 247                         uu_panic("uu_list_destroy(%p):  outstanding walkers\n",
 248                             lp);
 249                 }
 250         }
 251
 252         (void) pthread_mutex_lock(&pp->ulp_lock);
 253         UU_LIST_PTR(lp->ul_next_enc)->ul_prev_enc = lp->ul_prev_enc;
 254         UU_LIST_PTR(lp->ul_prev_enc)->ul_next_enc = lp->ul_next_enc;
 255         (void) pthread_mutex_unlock(&pp->ulp_lock);
 256         lp->ul_prev_enc = UU_PTR_ENCODE(NULL);
 257         lp->ul_next_enc = UU_PTR_ENCODE(NULL);
 258         lp->ul_pool = NULL;
 259         uu_free(lp);
 260 }
 261
 262 static void
 263 list_insert(uu_list_t *lp, uu_list_node_impl_t *np, uu_list_node_impl_t *prev,
 264     uu_list_node_impl_t *next)
 265 {
 266         if (lp->ul_debug) {
 267                 if (next->uln_prev != prev || prev->uln_next != next)
 268                         uu_panic("insert(%p): internal error: %p and %p not "
 269                             "neighbors\n", lp, next, prev);
 270
 271                 if (np->uln_next != POOL_TO_MARKER(lp->ul_pool) ||
 272                     np->uln_prev != NULL) {
 273                         uu_panic("insert(%p): elem %p node %p corrupt, "
 274                             "not initialized, or already in a list.\n",
 275                             lp, NODE_TO_ELEM(lp, np), np);
 276                 }
 277                 /*
 278                  * invalidate outstanding uu_list_index_ts.
 279                  */
 280                 lp->ul_index = INDEX_NEXT(lp->ul_index);
 281         }
 282         np->uln_next = next;
 283         np->uln_prev = prev;
 284         next->uln_prev = np;
 285         prev->uln_next = np;
 286
 287         lp->ul_numnodes++;
 288 }
 289
 290 void
 291 uu_list_insert(uu_list_t *lp, void *elem, uu_list_index_t idx)
 292 {
 293         uu_list_node_impl_t *np;
 294
 295         np = INDEX_TO_NODE(idx);
 296         if (np == NULL)
 297                 np = &lp->ul_null_node;
 298
 299         if (lp->ul_debug) {
 300                 if (!INDEX_VALID(lp, idx))
 301                         uu_panic("uu_list_insert(%p, %p, %p): %s\n",
 302                             lp, elem, idx,
 303                             INDEX_CHECK(idx)? "outdated index" :
 304                             "invalid index");
 305                 if (np->uln_prev == NULL)
 306                         uu_panic("uu_list_insert(%p, %p, %p): out-of-date "
 307                             "index\n", lp, elem, idx);
 308         }
 309
 310         list_insert(lp, ELEM_TO_NODE(lp, elem), np->uln_prev, np);
 311 }
 312
 313 void *
 314 uu_list_find(uu_list_t *lp, void *elem, void *private, uu_list_index_t *out)
 315 {
 316         int sorted = lp->ul_sorted;
 317         uu_compare_fn_t *func = lp->ul_pool->ulp_cmp;
 318         uu_list_node_impl_t *np;
 319
 320         if (func == NULL) {
 321                 if (out != NULL)
 322                         *out = 0;
 323                 uu_set_error(UU_ERROR_NOT_SUPPORTED);
 324                 return (NULL);
 325         }
 326         for (np = lp->ul_null_node.uln_next; np != &lp->ul_null_node;
 327             np = np->uln_next) {
 328                 void *ep = NODE_TO_ELEM(lp, np);
 329                 int cmp = func(ep, elem, private);
 330                 if (cmp == 0) {
 331                         if (out != NULL)
 332                                 *out = NODE_TO_INDEX(lp, np);
 333                         return (ep);
 334                 }
 335                 if (sorted && cmp > 0) {
 336                         if (out != NULL)
 337                                 *out = NODE_TO_INDEX(lp, np);
 338                         return (NULL);
 339                 }
 340         }
 341         if (out != NULL)
 342                 *out = NODE_TO_INDEX(lp, 0);
 343         return (NULL);
 344 }
 345
 346 void *
 347 uu_list_nearest_next(uu_list_t *lp, uu_list_index_t idx)
 348 {
 349         uu_list_node_impl_t *np = INDEX_TO_NODE(idx);
 350
 351         if (np == NULL)
 352                 np = &lp->ul_null_node;
 353
 354         if (lp->ul_debug) {
 355                 if (!INDEX_VALID(lp, idx))
 356                         uu_panic("uu_list_nearest_next(%p, %p): %s\n",
 357                             lp, idx, INDEX_CHECK(idx)? "outdated index" :
 358                             "invalid index");
 359                 if (np->uln_prev == NULL)
 360                         uu_panic("uu_list_nearest_next(%p, %p): out-of-date "
 361                             "index\n", lp, idx);
 362         }
 363
 364         if (np == &lp->ul_null_node)
 365                 return (NULL);
 366         else
 367                 return (NODE_TO_ELEM(lp, np));
 368 }
 369
 370 void *
 371 uu_list_nearest_prev(uu_list_t *lp, uu_list_index_t idx)
 372 {
 373         uu_list_node_impl_t *np = INDEX_TO_NODE(idx);
 374
 375         if (np == NULL)
 376                 np = &lp->ul_null_node;
 377
 378         if (lp->ul_debug) {
 379                 if (!INDEX_VALID(lp, idx))
 380                         uu_panic("uu_list_nearest_prev(%p, %p): %s\n",
 381                             lp, idx, INDEX_CHECK(idx)? "outdated index" :
 382                             "invalid index");
 383                 if (np->uln_prev == NULL)
 384                         uu_panic("uu_list_nearest_prev(%p, %p): out-of-date "
 385                             "index\n", lp, idx);
 386         }
 387
 388         if ((np = np->uln_prev) == &lp->ul_null_node)
 389                 return (NULL);
 390         else
 391                 return (NODE_TO_ELEM(lp, np));
 392 }
 393
 394 static void
 395 list_walk_init(uu_list_walk_t *wp, uu_list_t *lp, uint32_t flags)
 396 {
 397         uu_list_walk_t *next, *prev;
 398
 399         int robust = (flags & UU_WALK_ROBUST);
 400         int direction = (flags & UU_WALK_REVERSE)? -1 : 1;
 401
 402         (void) memset(wp, 0, sizeof (*wp));
 403         wp->ulw_list = lp;
 404         wp->ulw_robust = robust;
 405         wp->ulw_dir = direction;
 406         if (direction > 0)
 407                 wp->ulw_next_result = lp->ul_null_node.uln_next;
 408         else
 409                 wp->ulw_next_result = lp->ul_null_node.uln_prev;
 410
 411         if (lp->ul_debug || robust) {
 412                 wp->ulw_next = next = &lp->ul_null_walk;
 413                 wp->ulw_prev = prev = next->ulw_prev;
 414                 next->ulw_prev = wp;
 415                 prev->ulw_next = wp;
 416         }
 417 }
 418
 419 static uu_list_node_impl_t *
 420 list_walk_advance(uu_list_walk_t *wp, uu_list_t *lp)
 421 {
 422         uu_list_node_impl_t *np = wp->ulw_next_result;
 423         uu_list_node_impl_t *next;
 424
 425         if (np == &lp->ul_null_node)
 426                 return (NULL);
 427
 428         next = (wp->ulw_dir > 0)? np->uln_next : np->uln_prev;
 429
 430         wp->ulw_next_result = next;
 431         return (np);
 432 }
 433
 434 static void
 435 list_walk_fini(uu_list_walk_t *wp)
 436 {
 437         /* GLXXX debugging? */
 438         if (wp->ulw_next != NULL) {
 439                 wp->ulw_next->ulw_prev = wp->ulw_prev;
 440                 wp->ulw_prev->ulw_next = wp->ulw_next;
 441                 wp->ulw_next = NULL;
 442                 wp->ulw_prev = NULL;
 443         }
 444         wp->ulw_list = NULL;
 445         wp->ulw_next_result = NULL;
 446 }
 447
 448 uu_list_walk_t *
 449 uu_list_walk_start(uu_list_t *lp, uint32_t flags)
 450 {
 451         uu_list_walk_t *wp;
 452
 453         if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
 454                 uu_set_error(UU_ERROR_UNKNOWN_FLAG);
 455                 return (NULL);
 456         }
 457
 458         wp = uu_zalloc(sizeof (*wp));
 459         if (wp == NULL) {
 460                 uu_set_error(UU_ERROR_NO_MEMORY);
 461                 return (NULL);
 462         }
 463
 464         list_walk_init(wp, lp, flags);
 465         return (wp);
 466 }
 467
 468 void *
 469 uu_list_walk_next(uu_list_walk_t *wp)
 470 {
 471         uu_list_t *lp = wp->ulw_list;
 472         uu_list_node_impl_t *np = list_walk_advance(wp, lp);
 473
 474         if (np == NULL)
 475                 return (NULL);
 476
 477         return (NODE_TO_ELEM(lp, np));
 478 }
 479
 480 void
 481 uu_list_walk_end(uu_list_walk_t *wp)
 482 {
 483         list_walk_fini(wp);
 484         uu_free(wp);
 485 }
 486
 487 int
 488 uu_list_walk(uu_list_t *lp, uu_walk_fn_t *func, void *private, uint32_t flags)
 489 {
 490         uu_list_node_impl_t *np;
 491
 492         int status = UU_WALK_NEXT;
 493
 494         int robust = (flags & UU_WALK_ROBUST);
 495         int reverse = (flags & UU_WALK_REVERSE);
 496
 497         if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
 498                 uu_set_error(UU_ERROR_UNKNOWN_FLAG);
 499                 return (-1);
 500         }
 501
 502         if (lp->ul_debug || robust) {
 503                 uu_list_walk_t my_walk;
 504                 void *e;
 505
 506                 list_walk_init(&my_walk, lp, flags);
 507                 while (status == UU_WALK_NEXT &&
 508                     (e = uu_list_walk_next(&my_walk)) != NULL)
 509                         status = (*func)(e, private);
 510                 list_walk_fini(&my_walk);
 511         } else {
 512                 if (!reverse) {
 513                         for (np = lp->ul_null_node.uln_next;
 514                             status == UU_WALK_NEXT && np != &lp->ul_null_node;
 515                             np = np->uln_next) {
 516                                 status = (*func)(NODE_TO_ELEM(lp, np), private);
 517                         }
 518                 } else {
 519                         for (np = lp->ul_null_node.uln_prev;
 520                             status == UU_WALK_NEXT && np != &lp->ul_null_node;
 521                             np = np->uln_prev) {
 522                                 status = (*func)(NODE_TO_ELEM(lp, np), private);
 523                         }
 524                 }
 525         }
 526         if (status >= 0)
 527                 return (0);
 528         uu_set_error(UU_ERROR_CALLBACK_FAILED);
 529         return (-1);
 530 }
 531
 532 void
 533 uu_list_remove(uu_list_t *lp, void *elem)
 534 {
 535         uu_list_node_impl_t *np = ELEM_TO_NODE(lp, elem);
 536         uu_list_walk_t *wp;
 537
 538         if (lp->ul_debug) {
 539                 if (np->uln_prev == NULL)
 540                         uu_panic("uu_list_remove(%p, %p): elem not on list\n",
 541                             lp, elem);
 542                 /*
 543                  * invalidate outstanding uu_list_index_ts.
 544                  */
 545                 lp->ul_index = INDEX_NEXT(lp->ul_index);
 546         }
 547
 548         /*
 549          * robust walkers must be advanced.  In debug mode, non-robust
 550          * walkers are also on the list.  If there are any, it's an error.
 551          */
 552         for (wp = lp->ul_null_walk.ulw_next; wp != &lp->ul_null_walk;
 553             wp = wp->ulw_next) {
 554                 if (wp->ulw_robust) {
 555                         if (np == wp->ulw_next_result)
 556                                 (void) list_walk_advance(wp, lp);
 557                 } else if (wp->ulw_next_result != NULL) {
 558                         uu_panic("uu_list_remove(%p, %p): active non-robust "
 559                             "walker\n", lp, elem);
 560                 }
 561         }
 562
 563         np->uln_next->uln_prev = np->uln_prev;
 564         np->uln_prev->uln_next = np->uln_next;
 565
 566         lp->ul_numnodes--;
 567
 568         np->uln_next = POOL_TO_MARKER(lp->ul_pool);
 569         np->uln_prev = NULL;
 570 }
 571
 572 void *
 573 uu_list_teardown(uu_list_t *lp, void **cookie)
 574 {
 575         void *ep;
 576
 577         /*
 578          * XXX: disable list modification until list is empty
 579          */
 580         if (lp->ul_debug && *cookie != NULL)
 581                 uu_panic("uu_list_teardown(%p, %p): unexpected cookie\n", lp,
 582                     cookie);
 583
 584         ep = uu_list_first(lp);
 585         if (ep)
 586                 uu_list_remove(lp, ep);
 587         return (ep);
 588 }
 589
 590 int
 591 uu_list_insert_before(uu_list_t *lp, void *target, void *elem)
 592 {
 593         uu_list_node_impl_t *np = ELEM_TO_NODE(lp, target);
 594
 595         if (target == NULL)
 596                 np = &lp->ul_null_node;
 597
 598         if (lp->ul_debug) {
 599                 if (np->uln_prev == NULL)
 600                         uu_panic("uu_list_insert_before(%p, %p, %p): %p is "
 601                             "not currently on a list\n",
 602                             lp, target, elem, target);
 603         }
 604         if (lp->ul_sorted) {
 605                 if (lp->ul_debug)
 606                         uu_panic("uu_list_insert_before(%p, ...): list is "
 607                             "UU_LIST_SORTED\n", lp);
 608                 uu_set_error(UU_ERROR_NOT_SUPPORTED);
 609                 return (-1);
 610         }
 611
 612         list_insert(lp, ELEM_TO_NODE(lp, elem), np->uln_prev, np);
 613         return (0);
 614 }
 615
 616 int
 617 uu_list_insert_after(uu_list_t *lp, void *target, void *elem)
 618 {
 619         uu_list_node_impl_t *np = ELEM_TO_NODE(lp, target);
 620
 621         if (target == NULL)
 622                 np = &lp->ul_null_node;
 623
 624         if (lp->ul_debug) {
 625                 if (np->uln_prev == NULL)
 626                         uu_panic("uu_list_insert_after(%p, %p, %p): %p is "
 627                             "not currently on a list\n",
 628                             lp, target, elem, target);
 629         }
 630         if (lp->ul_sorted) {
 631                 if (lp->ul_debug)
 632                         uu_panic("uu_list_insert_after(%p, ...): list is "
 633                             "UU_LIST_SORTED\n", lp);
 634                 uu_set_error(UU_ERROR_NOT_SUPPORTED);
 635                 return (-1);
 636         }
 637
 638         list_insert(lp, ELEM_TO_NODE(lp, elem), np, np->uln_next);
 639         return (0);
 640 }
 641
 642 size_t
 643 uu_list_numnodes(uu_list_t *lp)
 644 {
 645         return (lp->ul_numnodes);
 646 }
 647
 648 void *
 649 uu_list_first(uu_list_t *lp)
 650 {
 651         uu_list_node_impl_t *n = lp->ul_null_node.uln_next;
 652         if (n == &lp->ul_null_node)
 653                 return (NULL);
 654         return (NODE_TO_ELEM(lp, n));
 655 }
 656
 657 void *
 658 uu_list_last(uu_list_t *lp)
 659 {
 660         uu_list_node_impl_t *n = lp->ul_null_node.uln_prev;
 661         if (n == &lp->ul_null_node)
 662                 return (NULL);
 663         return (NODE_TO_ELEM(lp, n));
 664 }
 665
 666 void *
 667 uu_list_next(uu_list_t *lp, void *elem)
 668 {
 669         uu_list_node_impl_t *n = ELEM_TO_NODE(lp, elem);
 670
 671         n = n->uln_next;
 672         if (n == &lp->ul_null_node)
 673                 return (NULL);
 674         return (NODE_TO_ELEM(lp, n));
 675 }
 676
 677 void *
 678 uu_list_prev(uu_list_t *lp, void *elem)
 679 {
 680         uu_list_node_impl_t *n = ELEM_TO_NODE(lp, elem);
 681
 682         n = n->uln_prev;
 683         if (n == &lp->ul_null_node)
 684                 return (NULL);
 685         return (NODE_TO_ELEM(lp, n));
 686 }
 687
 688 /*
 689  * called from uu_lockup() and uu_release(), as part of our fork1()-safety.
 690  */
 691 void
 692 uu_list_lockup(void)
 693 {
 694         uu_list_pool_t *pp;
 695
 696         (void) pthread_mutex_lock(&uu_lpool_list_lock);
 697         for (pp = uu_null_lpool.ulp_next; pp != &uu_null_lpool;
 698             pp = pp->ulp_next)
 699                 (void) pthread_mutex_lock(&pp->ulp_lock);
 700 }
 701
 702 void
 703 uu_list_release(void)
 704 {
 705         uu_list_pool_t *pp;
 706
 707         for (pp = uu_null_lpool.ulp_next; pp != &uu_null_lpool;
 708             pp = pp->ulp_next)
 709                 (void) pthread_mutex_unlock(&pp->ulp_lock);
 710         (void) pthread_mutex_unlock(&uu_lpool_list_lock);
 711 }