git.sur5r.net Git - openldap/blob - servers/slapd/sl_malloc.c

   1 /* sl_malloc.c - malloc routines using a per-thread slab */
   2 /* $OpenLDAP$ */
   3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   4  *
   5  * Copyright 2003-2011 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16
  17 #include "portable.h"
  18
  19 #include <stdio.h>
  20 #include <ac/string.h>
  21
  22 #include "slap.h"
  23
  24 /*
  25  * This allocator returns temporary memory from a slab in a given memory
  26  * context, aligned on a 2-int boundary.  It cannot be used for data
  27  * which will outlive the task allocating it.
  28  *
  29  * A new memory context attaches to the creator's thread context, if any.
  30  * Threads cannot use other threads' memory contexts; there are no locks.
  31  *
  32  * The caller of slap_sl_malloc, usually a thread pool task, must
  33  * slap_sl_free the memory before finishing: New tasks reuse the context
  34  * and normally reset it, reclaiming memory left over from last task.
  35  *
  36  * The allocator helps memory fragmentation, speed and memory leaks.
  37  * It is not (yet) reliable as a garbage collector:
  38  *
  39  * It falls back to context NULL - plain ber_memalloc() - when the
  40  * context's slab is full.  A reset does not reclaim such memory.
  41  * Conversely, free/realloc of data not from the given context assumes
  42  * context NULL.  The data must not belong to another memory context.
  43  *
  44  * Code which has lost track of the current memory context can try
  45  * slap_sl_context() or ch_malloc.c:ch_free/ch_realloc().
  46  *
  47  * Allocations cannot yet return failure.  Like ch_malloc, they succeed
  48  * or abort slapd.  This will change, do fix code which assumes success.
  49  */
  50
  51 /*
  52  * The stack-based allocator stores (ber_len_t)sizeof(head+block) at
  53  * allocated blocks' head - and in freed blocks also at the tail, marked
  54  * by ORing *next* block's head with 1.  Freed blocks are only reclaimed
  55  * from the last block forward.  This is fast, but when a block is never
  56  * freed, older blocks will not be reclaimed until the slab is reset...
  57  */
  58
  59 #ifdef SLAP_NO_SL_MALLOC /* Useful with memory debuggers like Valgrind */
  60 enum { No_sl_malloc = 1 };
  61 #else
  62 enum { No_sl_malloc = 0 };
  63 #endif
  64
  65 #define SLAP_SLAB_SOBLOCK 64
  66
  67 struct slab_object {
  68     void *so_ptr;
  69         int so_blockhead;
  70     LDAP_LIST_ENTRY(slab_object) so_link;
  71 };
  72
  73 struct slab_heap {
  74     void *sh_base;
  75     void *sh_last;
  76     void *sh_end;
  77         int sh_stack;
  78         int sh_maxorder;
  79     unsigned char **sh_map;
  80     LDAP_LIST_HEAD(sh_freelist, slab_object) *sh_free;
  81         LDAP_LIST_HEAD(sh_so, slab_object) sh_sopool;
  82 };
  83
  84 enum {
  85         Align = sizeof(ber_len_t) > 2*sizeof(int)
  86                 ? sizeof(ber_len_t) : 2*sizeof(int),
  87         Align_log2 = 1 + (Align>2) + (Align>4) + (Align>8) + (Align>16),
  88         order_start = Align_log2 - 1,
  89         pad = Align - 1
  90 };
  91
  92 static struct slab_object * slap_replenish_sopool(struct slab_heap* sh);
  93 #ifdef SLAPD_UNUSED
  94 static void print_slheap(int level, void *ctx);
  95 #endif
  96
  97 /* Keep memory context in a thread-local var, or in a global when no threads */
  98 #ifdef NO_THREADS
  99 static struct slab_heap *slheap;
 100 # define SET_MEMCTX(thrctx, memctx, sfree)      ((void) (slheap = (memctx)))
 101 # define GET_MEMCTX(thrctx, memctxp)            (*(memctxp) = slheap))
 102 #else
 103 # define memctx_key ((void *) slap_sl_mem_init)
 104 # define SET_MEMCTX(thrctx, memctx, kfree) \
 105         ldap_pvt_thread_pool_setkey(thrctx,memctx_key, memctx,kfree, NULL,NULL)
 106 # define GET_MEMCTX(thrctx, memctxp) \
 107         ((void) (*(memctxp) = NULL), \
 108          (void) ldap_pvt_thread_pool_getkey(thrctx,memctx_key, memctxp,NULL), \
 109          *(memctxp))
 110 #endif /* NO_THREADS */
 111
 112
 113 /* Destroy the context, or if key==NULL clean it up for reuse. */
 114 void
 115 slap_sl_mem_destroy(
 116         void *key,
 117         void *data
 118 )
 119 {
 120         struct slab_heap *sh = data;
 121         struct slab_object *so;
 122         int i;
 123
 124         if (!sh->sh_stack) {
 125                 for (i = 0; i <= sh->sh_maxorder - order_start; i++) {
 126                         so = LDAP_LIST_FIRST(&sh->sh_free[i]);
 127                         while (so) {
 128                                 struct slab_object *so_tmp = so;
 129                                 so = LDAP_LIST_NEXT(so, so_link);
 130                                 LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, so_tmp, so_link);
 131                         }
 132                         ch_free(sh->sh_map[i]);
 133                 }
 134                 ch_free(sh->sh_free);
 135                 ch_free(sh->sh_map);
 136
 137                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 138                 while (so) {
 139                         struct slab_object *so_tmp = so;
 140                         so = LDAP_LIST_NEXT(so, so_link);
 141                         if (!so_tmp->so_blockhead) {
 142                                 LDAP_LIST_REMOVE(so_tmp, so_link);
 143                         }
 144                 }
 145                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 146                 while (so) {
 147                         struct slab_object *so_tmp = so;
 148                         so = LDAP_LIST_NEXT(so, so_link);
 149                         ch_free(so_tmp);
 150                 }
 151         }
 152
 153         if (key != NULL) {
 154                 ber_memfree_x(sh->sh_base, NULL);
 155                 ber_memfree_x(sh, NULL);
 156         }
 157 }
 158
 159 BerMemoryFunctions slap_sl_mfuncs =
 160         { slap_sl_malloc, slap_sl_calloc, slap_sl_realloc, slap_sl_free };
 161
 162 void
 163 slap_sl_mem_init()
 164 {
 165         assert( Align == 1 << Align_log2 );
 166
 167         ber_set_option( NULL, LBER_OPT_MEMORY_FNS, &slap_sl_mfuncs );
 168 }
 169
 170 /* Create, reset or just return the memory context of the current thread. */
 171 void *
 172 slap_sl_mem_create(
 173         ber_len_t size,
 174         int stack,
 175         void *thrctx,
 176         int new
 177 )
 178 {
 179         void *memctx;
 180         struct slab_heap *sh;
 181         ber_len_t size_shift;
 182         struct slab_object *so;
 183         enum { Base_offset = (unsigned) -sizeof(ber_len_t) % Align };
 184
 185         sh = GET_MEMCTX(thrctx, &memctx);
 186         if ( sh && !new )
 187                 return sh;
 188
 189         /* round up to doubleword boundary */
 190         size = (size + Align-1) & -Align;
 191
 192         if (!sh) {
 193                 sh = ch_malloc(sizeof(struct slab_heap));
 194                 sh->sh_base = ch_malloc(size);
 195                 SET_MEMCTX(thrctx, sh, slap_sl_mem_destroy);
 196         } else {
 197                 slap_sl_mem_destroy(NULL, sh);
 198                 if ( size > (char *)sh->sh_end - (char *)sh->sh_base ) {
 199                         void    *newptr;
 200
 201                         newptr = ch_realloc( sh->sh_base, size );
 202                         if ( newptr == NULL ) return NULL;
 203                         sh->sh_base = newptr;
 204                 }
 205         }
 206         sh->sh_end = (char *) sh->sh_base + size;
 207
 208         sh->sh_stack = stack;
 209         if (stack) {
 210                 /* Align first returned block (sh_last + head) */
 211                 sh->sh_last = (char *) sh->sh_base + Base_offset;
 212
 213         } else {
 214                 int i, order = -1, order_end = -1;
 215
 216                 size_shift = size - 1;
 217                 do {
 218                         order_end++;
 219                 } while (size_shift >>= 1);
 220                 order = order_end - order_start + 1;
 221                 sh->sh_maxorder = order_end;
 222
 223                 sh->sh_free = (struct sh_freelist *)
 224                                                 ch_malloc(order * sizeof(struct sh_freelist));
 225                 for (i = 0; i < order; i++) {
 226                         LDAP_LIST_INIT(&sh->sh_free[i]);
 227                 }
 228
 229                 LDAP_LIST_INIT(&sh->sh_sopool);
 230
 231                 if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
 232                         slap_replenish_sopool(sh);
 233                 }
 234                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 235                 LDAP_LIST_REMOVE(so, so_link);
 236                 so->so_ptr = sh->sh_base;
 237
 238                 LDAP_LIST_INSERT_HEAD(&sh->sh_free[order-1], so, so_link);
 239
 240                 sh->sh_map = (unsigned char **)
 241                                         ch_malloc(order * sizeof(unsigned char *));
 242                 for (i = 0; i < order; i++) {
 243                         int shiftamt = order_start + 1 + i;
 244                         int nummaps = size >> shiftamt;
 245                         assert(nummaps);
 246                         nummaps >>= 3;
 247                         if (!nummaps) nummaps = 1;
 248                         sh->sh_map[i] = (unsigned char *) ch_malloc(nummaps);
 249                         memset(sh->sh_map[i], 0, nummaps);
 250                 }
 251         }
 252         return sh;
 253 }
 254
 255 /*
 256  * Separate memory context from thread context.  Future users must
 257  * know the context, since ch_free/slap_sl_context() cannot find it.
 258  */
 259 void
 260 slap_sl_mem_detach(
 261         void *thrctx,
 262         void *memctx
 263 )
 264 {
 265         SET_MEMCTX(thrctx, NULL, 0);
 266 }
 267
 268 void *
 269 slap_sl_malloc(
 270     ber_len_t   size,
 271     void *ctx
 272 )
 273 {
 274         struct slab_heap *sh = ctx;
 275         ber_len_t *ptr, *newptr;
 276
 277         /* ber_set_option calls us like this */
 278         if (No_sl_malloc || !ctx) {
 279                 newptr = ber_memalloc_x( size, NULL );
 280                 if ( newptr ) return newptr;
 281                 Debug(LDAP_DEBUG_ANY, "slap_sl_malloc of %lu bytes failed\n",
 282                         (unsigned long) size, 0, 0);
 283                 assert( 0 );
 284                 exit( EXIT_FAILURE );
 285         }
 286
 287         /* Add room for head, ensure room for tail when freed, and
 288          * round up to doubleword boundary. */
 289         size = (size + sizeof(ber_len_t) + Align-1 + !size) & -Align;
 290
 291         if (sh->sh_stack) {
 292                 if (size < (ber_len_t) ((char *) sh->sh_end - (char *) sh->sh_last)) {
 293                         newptr = sh->sh_last;
 294                         sh->sh_last = (char *) sh->sh_last + size;
 295                         *newptr++ = size;
 296                         return( (void *)newptr );
 297                 }
 298
 299                 size -= sizeof(ber_len_t);
 300
 301         } else {
 302                 struct slab_object *so_new, *so_left, *so_right;
 303                 ber_len_t size_shift;
 304                 unsigned long diff;
 305                 int i, j, order = -1;
 306
 307                 size_shift = size - 1;
 308                 do {
 309                         order++;
 310                 } while (size_shift >>= 1);
 311
 312                 size -= sizeof(ber_len_t);
 313
 314                 for (i = order; i <= sh->sh_maxorder &&
 315                                 LDAP_LIST_EMPTY(&sh->sh_free[i-order_start]); i++);
 316
 317                 if (i == order) {
 318                         so_new = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
 319                         LDAP_LIST_REMOVE(so_new, so_link);
 320                         ptr = so_new->so_ptr;
 321                         diff = (unsigned long)((char*)ptr -
 322                                         (char*)sh->sh_base) >> (order + 1);
 323                         sh->sh_map[order-order_start][diff>>3] |= (1 << (diff & 0x7));
 324                         *ptr++ = size;
 325                         LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, so_new, so_link);
 326                         return((void*)ptr);
 327                 } else if (i <= sh->sh_maxorder) {
 328                         for (j = i; j > order; j--) {
 329                                 so_left = LDAP_LIST_FIRST(&sh->sh_free[j-order_start]);
 330                                 LDAP_LIST_REMOVE(so_left, so_link);
 331                                 if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
 332                                         slap_replenish_sopool(sh);
 333                                 }
 334                                 so_right = LDAP_LIST_FIRST(&sh->sh_sopool);
 335                                 LDAP_LIST_REMOVE(so_right, so_link);
 336                                 so_right->so_ptr = (void *)((char *)so_left->so_ptr + (1 << j));
 337                                 if (j == order + 1) {
 338                                         ptr = so_left->so_ptr;
 339                                         diff = (unsigned long)((char*)ptr -
 340                                                         (char*)sh->sh_base) >> (order+1);
 341                                         sh->sh_map[order-order_start][diff>>3] |=
 342                                                         (1 << (diff & 0x7));
 343                                         *ptr++ = size;
 344                                         LDAP_LIST_INSERT_HEAD(
 345                                                         &sh->sh_free[j-1-order_start], so_right, so_link);
 346                                         LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, so_left, so_link);
 347                                         return((void*)ptr);
 348                                 } else {
 349                                         LDAP_LIST_INSERT_HEAD(
 350                                                         &sh->sh_free[j-1-order_start], so_right, so_link);
 351                                         LDAP_LIST_INSERT_HEAD(
 352                                                         &sh->sh_free[j-1-order_start], so_left, so_link);
 353                                 }
 354                         }
 355                 }
 356                 /* FIXME: missing return; guessing we failed... */
 357         }
 358
 359         Debug(LDAP_DEBUG_TRACE,
 360                 "sl_malloc %lu: ch_malloc\n",
 361                 (unsigned long) size, 0, 0);
 362         return ch_malloc(size);
 363 }
 364
 365 #define LIM_SQRT(t) /* some value < sqrt(max value of unsigned type t) */ \
 366         ((0UL|(t)-1) >>31>>31 > 1 ? ((t)1 <<32) - 1 : \
 367          (0UL|(t)-1) >>31 ? 65535U : (0UL|(t)-1) >>15 ? 255U : 15U)
 368
 369 void *
 370 slap_sl_calloc( ber_len_t n, ber_len_t size, void *ctx )
 371 {
 372         void *newptr;
 373         ber_len_t total = n * size;
 374
 375         /* The sqrt test is a slight optimization: often avoids the division */
 376         if ((n | size) <= LIM_SQRT(ber_len_t) || n == 0 || total/n == size) {
 377                 newptr = slap_sl_malloc( total, ctx );
 378                 memset( newptr, 0, n*size );
 379         } else {
 380                 Debug(LDAP_DEBUG_ANY, "slap_sl_calloc(%lu,%lu) out of range\n",
 381                         (unsigned long) n, (unsigned long) size, 0);
 382                 assert(0);
 383                 exit(EXIT_FAILURE);
 384         }
 385         return newptr;
 386 }
 387
 388 void *
 389 slap_sl_realloc(void *ptr, ber_len_t size, void *ctx)
 390 {
 391         struct slab_heap *sh = ctx;
 392         ber_len_t oldsize, *p = (ber_len_t *) ptr, *nextp;
 393         void *newptr;
 394
 395         if (ptr == NULL)
 396                 return slap_sl_malloc(size, ctx);
 397
 398         /* Not our memory? */
 399         if (No_sl_malloc || !sh || ptr < sh->sh_base || ptr >= sh->sh_end) {
 400                 /* Like ch_realloc(), except not trying a new context */
 401                 newptr = ber_memrealloc_x(ptr, size, NULL);
 402                 if (newptr) {
 403                         return newptr;
 404                 }
 405                 Debug(LDAP_DEBUG_ANY, "slap_sl_realloc of %lu bytes failed\n",
 406                         (unsigned long) size, 0, 0);
 407                 assert(0);
 408                 exit( EXIT_FAILURE );
 409         }
 410
 411         if (size == 0) {
 412                 slap_sl_free(ptr, ctx);
 413                 return NULL;
 414         }
 415
 416         oldsize = p[-1];
 417
 418         if (sh->sh_stack) {
 419                 /* Add room for head, round up to doubleword boundary */
 420                 size = (size + sizeof(ber_len_t) + Align-1) & -Align;
 421
 422                 p--;
 423
 424                 /* Never shrink blocks */
 425                 if (size <= oldsize) {
 426                         return ptr;
 427                 }
 428
 429                 oldsize &= -2;
 430                 nextp = (ber_len_t *) ((char *) p + oldsize);
 431
 432                 /* If reallocing the last block, try to grow it */
 433                 if (nextp == sh->sh_last) {
 434                         if (size < (ber_len_t) ((char *) sh->sh_end - (char *) p)) {
 435                                 sh->sh_last = (char *) p + size;
 436                                 p[0] = (p[0] & 1) | size;
 437                                 return ptr;
 438                         }
 439
 440                 /* Nowhere to grow, need to alloc and copy */
 441                 } else {
 442                         /* Slight optimization of the final realloc variant */
 443                         newptr = slap_sl_malloc(size-sizeof(ber_len_t), ctx);
 444                         AC_MEMCPY(newptr, ptr, oldsize-sizeof(ber_len_t));
 445                         /* Not last block, can just mark old region as free */
 446                         nextp[-1] = oldsize;
 447                         nextp[0] |= 1;
 448                         return newptr;
 449                 }
 450
 451                 size -= sizeof(ber_len_t);
 452                 oldsize -= sizeof(ber_len_t);
 453
 454         } else if (oldsize > size) {
 455                 oldsize = size;
 456         }
 457
 458         newptr = slap_sl_malloc(size, ctx);
 459         AC_MEMCPY(newptr, ptr, oldsize);
 460         slap_sl_free(ptr, ctx);
 461         return newptr;
 462 }
 463
 464 void
 465 slap_sl_free(void *ptr, void *ctx)
 466 {
 467         struct slab_heap *sh = ctx;
 468         ber_len_t size;
 469         ber_len_t *p = ptr, *nextp, *tmpp;
 470
 471         if (!ptr)
 472                 return;
 473
 474         if (No_sl_malloc || !sh || ptr < sh->sh_base || ptr >= sh->sh_end) {
 475                 ber_memfree_x(ptr, NULL);
 476                 return;
 477         }
 478
 479         size = *(--p);
 480
 481         if (sh->sh_stack) {
 482                 size &= -2;
 483                 nextp = (ber_len_t *) ((char *) p + size);
 484                 if (sh->sh_last != nextp) {
 485                         /* Mark it free: tail = size, head of next block |= 1 */
 486                         nextp[-1] = size;
 487                         nextp[0] |= 1;
 488                 } else {
 489                         /* Reclaim freed block(s) off tail */
 490                         while (*p & 1) {
 491                                 p = (ber_len_t *) ((char *) p - p[-1]);
 492                         }
 493                         sh->sh_last = p;
 494                 }
 495
 496         } else {
 497                 int size_shift, order_size;
 498                 struct slab_object *so;
 499                 unsigned long diff;
 500                 int i, inserted = 0, order = -1;
 501
 502                 size_shift = size + sizeof(ber_len_t) - 1;
 503                 do {
 504                         order++;
 505                 } while (size_shift >>= 1);
 506
 507                 for (i = order, tmpp = p; i <= sh->sh_maxorder; i++) {
 508                         order_size = 1 << (i+1);
 509                         diff = (unsigned long)((char*)tmpp - (char*)sh->sh_base) >> (i+1);
 510                         sh->sh_map[i-order_start][diff>>3] &= (~(1 << (diff & 0x7)));
 511                         if (diff == ((diff>>1)<<1)) {
 512                                 if (!(sh->sh_map[i-order_start][(diff+1)>>3] &
 513                                                 (1<<((diff+1)&0x7)))) {
 514                                         so = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
 515                                         while (so) {
 516                                                 if ((char*)so->so_ptr == (char*)tmpp) {
 517                                                         LDAP_LIST_REMOVE( so, so_link );
 518                                                 } else if ((char*)so->so_ptr ==
 519                                                                 (char*)tmpp + order_size) {
 520                                                         LDAP_LIST_REMOVE(so, so_link);
 521                                                         break;
 522                                                 }
 523                                                 so = LDAP_LIST_NEXT(so, so_link);
 524                                         }
 525                                         if (so) {
 526                                                 if (i < sh->sh_maxorder) {
 527                                                         inserted = 1;
 528                                                         so->so_ptr = tmpp;
 529                                                         LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start+1],
 530                                                                         so, so_link);
 531                                                 }
 532                                                 continue;
 533                                         } else {
 534                                                 if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
 535                                                         slap_replenish_sopool(sh);
 536                                                 }
 537                                                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 538                                                 LDAP_LIST_REMOVE(so, so_link);
 539                                                 so->so_ptr = tmpp;
 540                                                 LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
 541                                                                 so, so_link);
 542                                                 break;
 543
 544                                                 Debug(LDAP_DEBUG_TRACE, "slap_sl_free: "
 545                                                         "free object not found while bit is clear.\n",
 546                                                         0, 0, 0);
 547                                                 assert(so != NULL);
 548
 549                                         }
 550                                 } else {
 551                                         if (!inserted) {
 552                                                 if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
 553                                                         slap_replenish_sopool(sh);
 554                                                 }
 555                                                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 556                                                 LDAP_LIST_REMOVE(so, so_link);
 557                                                 so->so_ptr = tmpp;
 558                                                 LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
 559                                                                 so, so_link);
 560                                         }
 561                                         break;
 562                                 }
 563                         } else {
 564                                 if (!(sh->sh_map[i-order_start][(diff-1)>>3] &
 565                                                 (1<<((diff-1)&0x7)))) {
 566                                         so = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
 567                                         while (so) {
 568                                                 if ((char*)so->so_ptr == (char*)tmpp) {
 569                                                         LDAP_LIST_REMOVE(so, so_link);
 570                                                 } else if ((char*)tmpp == (char *)so->so_ptr + order_size) {
 571                                                         LDAP_LIST_REMOVE(so, so_link);
 572                                                         tmpp = so->so_ptr;
 573                                                         break;
 574                                                 }
 575                                                 so = LDAP_LIST_NEXT(so, so_link);
 576                                         }
 577                                         if (so) {
 578                                                 if (i < sh->sh_maxorder) {
 579                                                         inserted = 1;
 580                                                         LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start+1],                                                                    so, so_link);
 581                                                         continue;
 582                                                 }
 583                                         } else {
 584                                                 if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
 585                                                         slap_replenish_sopool(sh);
 586                                                 }
 587                                                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 588                                                 LDAP_LIST_REMOVE(so, so_link);
 589                                                 so->so_ptr = tmpp;
 590                                                 LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
 591                                                                 so, so_link);
 592                                                 break;
 593
 594                                                 Debug(LDAP_DEBUG_TRACE, "slap_sl_free: "
 595                                                         "free object not found while bit is clear.\n",
 596                                                         0, 0, 0 );
 597                                                 assert(so != NULL);
 598
 599                                         }
 600                                 } else {
 601                                         if ( !inserted ) {
 602                                                 if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
 603                                                         slap_replenish_sopool(sh);
 604                                                 }
 605                                                 so = LDAP_LIST_FIRST(&sh->sh_sopool);
 606                                                 LDAP_LIST_REMOVE(so, so_link);
 607                                                 so->so_ptr = tmpp;
 608                                                 LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
 609                                                                 so, so_link);
 610                                         }
 611                                         break;
 612                                 }
 613                         }
 614                 }
 615         }
 616 }
 617
 618 /*
 619  * Return the memory context of the current thread if the given block of
 620  * memory belongs to it, otherwise return NULL.
 621  */
 622 void *
 623 slap_sl_context( void *ptr )
 624 {
 625         void *memctx;
 626         struct slab_heap *sh;
 627
 628         if ( slapMode & SLAP_TOOL_MODE ) return NULL;
 629
 630         sh = GET_MEMCTX(ldap_pvt_thread_pool_context(), &memctx);
 631         if (sh && ptr >= sh->sh_base && ptr <= sh->sh_end) {
 632                 return sh;
 633         }
 634         return NULL;
 635 }
 636
 637 static struct slab_object *
 638 slap_replenish_sopool(
 639     struct slab_heap* sh
 640 )
 641 {
 642     struct slab_object *so_block;
 643     int i;
 644
 645     so_block = (struct slab_object *)ch_malloc(
 646                     SLAP_SLAB_SOBLOCK * sizeof(struct slab_object));
 647
 648     if ( so_block == NULL ) {
 649         return NULL;
 650     }
 651
 652     so_block[0].so_blockhead = 1;
 653     LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, &so_block[0], so_link);
 654     for (i = 1; i < SLAP_SLAB_SOBLOCK; i++) {
 655         so_block[i].so_blockhead = 0;
 656         LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, &so_block[i], so_link );
 657     }
 658
 659     return so_block;
 660 }
 661
 662 #ifdef SLAPD_UNUSED
 663 static void
 664 print_slheap(int level, void *ctx)
 665 {
 666         struct slab_heap *sh = ctx;
 667         struct slab_object *so;
 668         int i, j, once = 0;
 669
 670         if (!ctx) {
 671                 Debug(level, "NULL memctx\n", 0, 0, 0);
 672                 return;
 673         }
 674
 675         Debug(level, "sh->sh_maxorder=%d\n", sh->sh_maxorder, 0, 0);
 676
 677         for (i = order_start; i <= sh->sh_maxorder; i++) {
 678                 once = 0;
 679                 Debug(level, "order=%d\n", i, 0, 0);
 680                 for (j = 0; j < (1<<(sh->sh_maxorder-i))/8; j++) {
 681                         Debug(level, "%02x ", sh->sh_map[i-order_start][j], 0, 0);
 682                         once = 1;
 683                 }
 684                 if (!once) {
 685                         Debug(level, "%02x ", sh->sh_map[i-order_start][0], 0, 0);
 686                 }
 687                 Debug(level, "\n", 0, 0, 0);
 688                 Debug(level, "free list:\n", 0, 0, 0);
 689                 so = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
 690                 while (so) {
 691                         Debug(level, "%p\n", so->so_ptr, 0, 0);
 692                         so = LDAP_LIST_NEXT(so, so_link);
 693                 }
 694         }
 695 }
 696 #endif