| 1 | /* Copyright (C) 2011, 2012, 2013, 2014 Free Software Foundation, Inc. |
| 2 | * |
| 3 | * This library is free software; you can redistribute it and/or |
| 4 | * modify it under the terms of the GNU Lesser General Public License |
| 5 | * as published by the Free Software Foundation; either version 3 of |
| 6 | * the License, or (at your option) any later version. |
| 7 | * |
| 8 | * This library is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 11 | * Lesser General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public |
| 14 | * License along with this library; if not, write to the Free Software |
| 15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 16 | * 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | |
| 20 | \f |
| 21 | #ifdef HAVE_CONFIG_H |
| 22 | # include <config.h> |
| 23 | #endif |
| 24 | |
| 25 | #include <assert.h> |
| 26 | |
| 27 | #include "libguile/bdw-gc.h" |
| 28 | #include <gc/gc_mark.h> |
| 29 | |
| 30 | #include "libguile/_scm.h" |
| 31 | #include "libguile/hash.h" |
| 32 | #include "libguile/eval.h" |
| 33 | #include "libguile/ports.h" |
| 34 | |
| 35 | #include "libguile/validate.h" |
| 36 | #include "libguile/weak-table.h" |
| 37 | |
| 38 | |
| 39 | /* Weak Tables |
| 40 | |
| 41 | This file implements weak hash tables. Weak hash tables are |
| 42 | generally used when you want to augment some object with additional |
| 43 | data, but when you don't have space to store the data in the object. |
| 44 | For example, procedure properties are implemented with weak tables. |
| 45 | |
| 46 | Weak tables are implemented using an open-addressed hash table. |
| 47 | Basically this means that there is an array of entries, and the item |
| 48 | is expected to be found the slot corresponding to its hash code, |
| 49 | modulo the length of the array. |
| 50 | |
| 51 | Collisions are handled using linear probing with the Robin Hood |
| 52 | technique. See Pedro Celis' paper, "Robin Hood Hashing": |
| 53 | |
| 54 | http://www.cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf |
| 55 | |
| 56 | The vector of entries is allocated in such a way that the GC doesn't |
| 57 | trace the weak values. For doubly-weak tables, this means that the |
| 58 | entries are allocated as an "atomic" piece of memory. Key-weak and |
| 59 | value-weak tables use a special GC kind with a custom mark procedure. |
| 60 | When items are added weakly into table, a disappearing link is |
| 61 | registered to their locations. If the referent is collected, then |
| 62 | that link will be zeroed out. |
| 63 | |
| 64 | An entry in the table consists of the key and the value, together |
| 65 | with the hash code of the key. We munge hash codes so that they are |
| 66 | never 0. In this way we can detect removed entries (key of zero but |
| 67 | nonzero hash code), and can then reshuffle elements as needed to |
| 68 | maintain the robin hood ordering. |
| 69 | |
| 70 | Compared to buckets-and-chains hash tables, open addressing has the |
| 71 | advantage that it is very cache-friendly. It also uses less memory. |
| 72 | |
| 73 | Implementation-wise, there are two things to note. |
| 74 | |
| 75 | 1. We assume that hash codes are evenly distributed across the |
| 76 | range of unsigned longs. The actual hash code stored in the |
| 77 | entry is left-shifted by 1 bit (losing 1 bit of hash precision), |
| 78 | and then or'd with 1. In this way we ensure that the hash field |
| 79 | of an occupied entry is nonzero. To map to an index, we |
| 80 | right-shift the hash by one, divide by the size, and take the |
| 81 | remainder. |
| 82 | |
| 83 | 2. Since the weak references are stored in an atomic region with |
| 84 | disappearing links, they need to be accessed with the GC alloc |
| 85 | lock. `copy_weak_entry' will do that for you. The hash code |
| 86 | itself can be read outside the lock, though. |
| 87 | */ |
| 88 | |
| 89 | |
| 90 | typedef struct { |
| 91 | unsigned long hash; |
| 92 | scm_t_bits key; |
| 93 | scm_t_bits value; |
| 94 | } scm_t_weak_entry; |
| 95 | |
| 96 | |
| 97 | struct weak_entry_data { |
| 98 | scm_t_weak_entry *in; |
| 99 | scm_t_weak_entry *out; |
| 100 | }; |
| 101 | |
| 102 | static void* |
| 103 | do_copy_weak_entry (void *data) |
| 104 | { |
| 105 | struct weak_entry_data *e = data; |
| 106 | |
| 107 | e->out->hash = e->in->hash; |
| 108 | e->out->key = e->in->key; |
| 109 | e->out->value = e->in->value; |
| 110 | |
| 111 | return NULL; |
| 112 | } |
| 113 | |
| 114 | static void |
| 115 | copy_weak_entry (scm_t_weak_entry *src, scm_t_weak_entry *dst) |
| 116 | { |
| 117 | struct weak_entry_data data; |
| 118 | |
| 119 | data.in = src; |
| 120 | data.out = dst; |
| 121 | |
| 122 | GC_call_with_alloc_lock (do_copy_weak_entry, &data); |
| 123 | } |
| 124 | |
| 125 | static void |
| 126 | register_disappearing_links (scm_t_weak_entry *entry, |
| 127 | SCM k, SCM v, |
| 128 | scm_t_weak_table_kind kind) |
| 129 | { |
| 130 | if (SCM_UNPACK (k) && SCM_HEAP_OBJECT_P (k) |
| 131 | && (kind == SCM_WEAK_TABLE_KIND_KEY |
| 132 | || kind == SCM_WEAK_TABLE_KIND_BOTH)) |
| 133 | SCM_I_REGISTER_DISAPPEARING_LINK ((void **) &entry->key, |
| 134 | SCM2PTR (k)); |
| 135 | |
| 136 | if (SCM_UNPACK (v) && SCM_HEAP_OBJECT_P (v) |
| 137 | && (kind == SCM_WEAK_TABLE_KIND_VALUE |
| 138 | || kind == SCM_WEAK_TABLE_KIND_BOTH)) |
| 139 | SCM_I_REGISTER_DISAPPEARING_LINK ((void **) &entry->value, |
| 140 | SCM2PTR (v)); |
| 141 | } |
| 142 | |
| 143 | static void |
| 144 | unregister_disappearing_links (scm_t_weak_entry *entry, |
| 145 | scm_t_weak_table_kind kind) |
| 146 | { |
| 147 | if (kind == SCM_WEAK_TABLE_KIND_KEY || kind == SCM_WEAK_TABLE_KIND_BOTH) |
| 148 | GC_unregister_disappearing_link ((void **) &entry->key); |
| 149 | |
| 150 | if (kind == SCM_WEAK_TABLE_KIND_VALUE || kind == SCM_WEAK_TABLE_KIND_BOTH) |
| 151 | GC_unregister_disappearing_link ((void **) &entry->value); |
| 152 | } |
| 153 | |
| 154 | #ifndef HAVE_GC_MOVE_DISAPPEARING_LINK |
| 155 | static void |
| 156 | GC_move_disappearing_link (void **from, void **to) |
| 157 | { |
| 158 | GC_unregister_disappearing_link (from); |
| 159 | SCM_I_REGISTER_DISAPPEARING_LINK (to, *to); |
| 160 | } |
| 161 | #endif |
| 162 | |
| 163 | static void |
| 164 | move_disappearing_links (scm_t_weak_entry *from, scm_t_weak_entry *to, |
| 165 | SCM key, SCM value, scm_t_weak_table_kind kind) |
| 166 | { |
| 167 | if ((kind == SCM_WEAK_TABLE_KIND_KEY || kind == SCM_WEAK_TABLE_KIND_BOTH) |
| 168 | && SCM_HEAP_OBJECT_P (key)) |
| 169 | GC_move_disappearing_link ((void **) &from->key, (void **) &to->key); |
| 170 | |
| 171 | if ((kind == SCM_WEAK_TABLE_KIND_VALUE || kind == SCM_WEAK_TABLE_KIND_BOTH) |
| 172 | && SCM_HEAP_OBJECT_P (value)) |
| 173 | GC_move_disappearing_link ((void **) &from->value, (void **) &to->value); |
| 174 | } |
| 175 | |
| 176 | static void |
| 177 | move_weak_entry (scm_t_weak_entry *from, scm_t_weak_entry *to, |
| 178 | scm_t_weak_table_kind kind) |
| 179 | { |
| 180 | if (from->hash) |
| 181 | { |
| 182 | scm_t_weak_entry copy; |
| 183 | |
| 184 | copy_weak_entry (from, ©); |
| 185 | to->hash = copy.hash; |
| 186 | to->key = copy.key; |
| 187 | to->value = copy.value; |
| 188 | |
| 189 | move_disappearing_links (from, to, |
| 190 | SCM_PACK (copy.key), SCM_PACK (copy.value), |
| 191 | kind); |
| 192 | } |
| 193 | else |
| 194 | { |
| 195 | to->hash = 0; |
| 196 | to->key = 0; |
| 197 | to->value = 0; |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | |
| 202 | typedef struct { |
| 203 | scm_t_weak_entry *entries; /* the data */ |
| 204 | scm_i_pthread_mutex_t lock; /* the lock */ |
| 205 | scm_t_weak_table_kind kind; /* what kind of table it is */ |
| 206 | unsigned long size; /* total number of slots. */ |
| 207 | unsigned long n_items; /* number of items in table */ |
| 208 | unsigned long lower; /* when to shrink */ |
| 209 | unsigned long upper; /* when to grow */ |
| 210 | int size_index; /* index into hashtable_size */ |
| 211 | int min_size_index; /* minimum size_index */ |
| 212 | } scm_t_weak_table; |
| 213 | |
| 214 | |
| 215 | #define SCM_WEAK_TABLE_P(x) (SCM_HAS_TYP7 (x, scm_tc7_weak_table)) |
| 216 | #define SCM_VALIDATE_WEAK_TABLE(pos, arg) \ |
| 217 | SCM_MAKE_VALIDATE_MSG (pos, arg, WEAK_TABLE_P, "weak-table") |
| 218 | #define SCM_WEAK_TABLE(x) ((scm_t_weak_table *) SCM_CELL_WORD_1 (x)) |
| 219 | |
| 220 | |
| 221 | static unsigned long |
| 222 | hash_to_index (unsigned long hash, unsigned long size) |
| 223 | { |
| 224 | return (hash >> 1) % size; |
| 225 | } |
| 226 | |
| 227 | static unsigned long |
| 228 | entry_distance (unsigned long hash, unsigned long k, unsigned long size) |
| 229 | { |
| 230 | unsigned long origin = hash_to_index (hash, size); |
| 231 | |
| 232 | if (k >= origin) |
| 233 | return k - origin; |
| 234 | else |
| 235 | /* The other key was displaced and wrapped around. */ |
| 236 | return size - origin + k; |
| 237 | } |
| 238 | |
| 239 | static void |
| 240 | rob_from_rich (scm_t_weak_table *table, unsigned long k) |
| 241 | { |
| 242 | unsigned long empty, size; |
| 243 | |
| 244 | size = table->size; |
| 245 | |
| 246 | /* If we are to free up slot K in the table, we need room to do so. */ |
| 247 | assert (table->n_items < size); |
| 248 | |
| 249 | empty = k; |
| 250 | do |
| 251 | empty = (empty + 1) % size; |
| 252 | while (table->entries[empty].hash); |
| 253 | |
| 254 | do |
| 255 | { |
| 256 | unsigned long last = empty ? (empty - 1) : (size - 1); |
| 257 | move_weak_entry (&table->entries[last], &table->entries[empty], |
| 258 | table->kind); |
| 259 | empty = last; |
| 260 | } |
| 261 | while (empty != k); |
| 262 | |
| 263 | table->entries[empty].hash = 0; |
| 264 | table->entries[empty].key = 0; |
| 265 | table->entries[empty].value = 0; |
| 266 | } |
| 267 | |
| 268 | static void |
| 269 | give_to_poor (scm_t_weak_table *table, unsigned long k) |
| 270 | { |
| 271 | /* Slot K was just freed up; possibly shuffle others down. */ |
| 272 | unsigned long size = table->size; |
| 273 | |
| 274 | while (1) |
| 275 | { |
| 276 | unsigned long next = (k + 1) % size; |
| 277 | unsigned long hash; |
| 278 | scm_t_weak_entry copy; |
| 279 | |
| 280 | hash = table->entries[next].hash; |
| 281 | |
| 282 | if (!hash || hash_to_index (hash, size) == next) |
| 283 | break; |
| 284 | |
| 285 | copy_weak_entry (&table->entries[next], ©); |
| 286 | |
| 287 | if (!copy.key || !copy.value) |
| 288 | /* Lost weak reference. */ |
| 289 | { |
| 290 | give_to_poor (table, next); |
| 291 | table->n_items--; |
| 292 | continue; |
| 293 | } |
| 294 | |
| 295 | move_weak_entry (&table->entries[next], &table->entries[k], |
| 296 | table->kind); |
| 297 | |
| 298 | k = next; |
| 299 | } |
| 300 | |
| 301 | /* We have shuffled down any entries that should be shuffled down; now |
| 302 | free the end. */ |
| 303 | table->entries[k].hash = 0; |
| 304 | table->entries[k].key = 0; |
| 305 | table->entries[k].value = 0; |
| 306 | } |
| 307 | |
| 308 | |
| 309 | \f |
| 310 | |
| 311 | /* The GC "kinds" for singly-weak tables. */ |
| 312 | static int weak_key_gc_kind; |
| 313 | static int weak_value_gc_kind; |
| 314 | |
| 315 | static struct GC_ms_entry * |
| 316 | mark_weak_key_table (GC_word *addr, struct GC_ms_entry *mark_stack_ptr, |
| 317 | struct GC_ms_entry *mark_stack_limit, GC_word env) |
| 318 | { |
| 319 | scm_t_weak_entry *entries = (scm_t_weak_entry*) addr; |
| 320 | unsigned long k, size = GC_size (addr) / sizeof (scm_t_weak_entry); |
| 321 | |
| 322 | for (k = 0; k < size; k++) |
| 323 | if (entries[k].hash && entries[k].key) |
| 324 | { |
| 325 | SCM value = SCM_PACK (entries[k].value); |
| 326 | mark_stack_ptr = GC_MARK_AND_PUSH ((GC_word*) SCM2PTR (value), |
| 327 | mark_stack_ptr, mark_stack_limit, |
| 328 | NULL); |
| 329 | } |
| 330 | |
| 331 | return mark_stack_ptr; |
| 332 | } |
| 333 | |
| 334 | static struct GC_ms_entry * |
| 335 | mark_weak_value_table (GC_word *addr, struct GC_ms_entry *mark_stack_ptr, |
| 336 | struct GC_ms_entry *mark_stack_limit, GC_word env) |
| 337 | { |
| 338 | scm_t_weak_entry *entries = (scm_t_weak_entry*) addr; |
| 339 | unsigned long k, size = GC_size (addr) / sizeof (scm_t_weak_entry); |
| 340 | |
| 341 | for (k = 0; k < size; k++) |
| 342 | if (entries[k].hash && entries[k].value) |
| 343 | { |
| 344 | SCM key = SCM_PACK (entries[k].key); |
| 345 | mark_stack_ptr = GC_MARK_AND_PUSH ((GC_word*) SCM2PTR (key), |
| 346 | mark_stack_ptr, mark_stack_limit, |
| 347 | NULL); |
| 348 | } |
| 349 | |
| 350 | return mark_stack_ptr; |
| 351 | } |
| 352 | |
| 353 | static scm_t_weak_entry * |
| 354 | allocate_entries (unsigned long size, scm_t_weak_table_kind kind) |
| 355 | { |
| 356 | scm_t_weak_entry *ret; |
| 357 | size_t bytes = size * sizeof (*ret); |
| 358 | |
| 359 | switch (kind) |
| 360 | { |
| 361 | case SCM_WEAK_TABLE_KIND_KEY: |
| 362 | ret = GC_generic_malloc (bytes, weak_key_gc_kind); |
| 363 | break; |
| 364 | case SCM_WEAK_TABLE_KIND_VALUE: |
| 365 | ret = GC_generic_malloc (bytes, weak_value_gc_kind); |
| 366 | break; |
| 367 | case SCM_WEAK_TABLE_KIND_BOTH: |
| 368 | ret = scm_gc_malloc_pointerless (bytes, "weak-table"); |
| 369 | break; |
| 370 | default: |
| 371 | abort (); |
| 372 | } |
| 373 | |
| 374 | memset (ret, 0, bytes); |
| 375 | |
| 376 | return ret; |
| 377 | } |
| 378 | |
| 379 | \f |
| 380 | |
| 381 | /* Growing or shrinking is triggered when the load factor |
| 382 | * |
| 383 | * L = N / S (N: number of items in table, S: bucket vector length) |
| 384 | * |
| 385 | * passes an upper limit of 0.9 or a lower limit of 0.2. |
| 386 | * |
| 387 | * The implementation stores the upper and lower number of items which |
| 388 | * trigger a resize in the hashtable object. |
| 389 | * |
| 390 | * Possible hash table sizes (primes) are stored in the array |
| 391 | * hashtable_size. |
| 392 | */ |
| 393 | |
| 394 | static unsigned long hashtable_size[] = { |
| 395 | 31, 61, 113, 223, 443, 883, 1759, 3517, 7027, 14051, 28099, 56197, 112363, |
| 396 | 224717, 449419, 898823, 1797641, 3595271, 7190537, 14381041, 28762081, |
| 397 | 57524111, 115048217, 230096423 |
| 398 | }; |
| 399 | |
| 400 | #define HASHTABLE_SIZE_N (sizeof(hashtable_size)/sizeof(unsigned long)) |
| 401 | |
| 402 | static int |
| 403 | compute_size_index (scm_t_weak_table *table) |
| 404 | { |
| 405 | int i = table->size_index; |
| 406 | |
| 407 | if (table->n_items < table->lower) |
| 408 | { |
| 409 | /* rehashing is not triggered when i <= min_size */ |
| 410 | do |
| 411 | --i; |
| 412 | while (i > table->min_size_index |
| 413 | && table->n_items < hashtable_size[i] / 5); |
| 414 | } |
| 415 | else if (table->n_items > table->upper) |
| 416 | { |
| 417 | ++i; |
| 418 | if (i >= HASHTABLE_SIZE_N) |
| 419 | /* The biggest size currently is 230096423, which for a 32-bit |
| 420 | machine will occupy 2.3GB of memory at a load of 80%. There |
| 421 | is probably something better to do here, but if you have a |
| 422 | weak map of that size, you are hosed in any case. */ |
| 423 | abort (); |
| 424 | } |
| 425 | |
| 426 | return i; |
| 427 | } |
| 428 | |
| 429 | static int |
| 430 | is_acceptable_size_index (scm_t_weak_table *table, int size_index) |
| 431 | { |
| 432 | int computed = compute_size_index (table); |
| 433 | |
| 434 | if (size_index == computed) |
| 435 | /* We were going to grow or shrink, and allocating the new vector |
| 436 | didn't change the target size. */ |
| 437 | return 1; |
| 438 | |
| 439 | if (size_index == computed + 1) |
| 440 | { |
| 441 | /* We were going to enlarge the table, but allocating the new |
| 442 | vector finalized some objects, making an enlargement |
| 443 | unnecessary. It might still be a good idea to use the larger |
| 444 | table, though. (This branch also gets hit if, while allocating |
| 445 | the vector, some other thread was actively removing items from |
| 446 | the table. That is less likely, though.) */ |
| 447 | unsigned long new_lower = hashtable_size[size_index] / 5; |
| 448 | |
| 449 | return table->size > new_lower; |
| 450 | } |
| 451 | |
| 452 | if (size_index == computed - 1) |
| 453 | { |
| 454 | /* We were going to shrink the table, but when we dropped the lock |
| 455 | to allocate the new vector, some other thread added elements to |
| 456 | the table. */ |
| 457 | return 0; |
| 458 | } |
| 459 | |
| 460 | /* The computed size differs from our newly allocated size by more |
| 461 | than one size index -- recalculate. */ |
| 462 | return 0; |
| 463 | } |
| 464 | |
| 465 | static void |
| 466 | resize_table (scm_t_weak_table *table) |
| 467 | { |
| 468 | scm_t_weak_entry *old_entries, *new_entries; |
| 469 | int new_size_index; |
| 470 | unsigned long old_size, new_size, old_k; |
| 471 | |
| 472 | do |
| 473 | { |
| 474 | new_size_index = compute_size_index (table); |
| 475 | if (new_size_index == table->size_index) |
| 476 | return; |
| 477 | new_size = hashtable_size[new_size_index]; |
| 478 | new_entries = allocate_entries (new_size, table->kind); |
| 479 | } |
| 480 | while (!is_acceptable_size_index (table, new_size_index)); |
| 481 | |
| 482 | old_entries = table->entries; |
| 483 | old_size = table->size; |
| 484 | |
| 485 | table->size_index = new_size_index; |
| 486 | table->size = new_size; |
| 487 | if (new_size_index <= table->min_size_index) |
| 488 | table->lower = 0; |
| 489 | else |
| 490 | table->lower = new_size / 5; |
| 491 | table->upper = 9 * new_size / 10; |
| 492 | table->n_items = 0; |
| 493 | table->entries = new_entries; |
| 494 | |
| 495 | for (old_k = 0; old_k < old_size; old_k++) |
| 496 | { |
| 497 | scm_t_weak_entry copy; |
| 498 | unsigned long new_k, distance; |
| 499 | |
| 500 | if (!old_entries[old_k].hash) |
| 501 | continue; |
| 502 | |
| 503 | copy_weak_entry (&old_entries[old_k], ©); |
| 504 | |
| 505 | if (!copy.key || !copy.value) |
| 506 | continue; |
| 507 | |
| 508 | new_k = hash_to_index (copy.hash, new_size); |
| 509 | |
| 510 | for (distance = 0; ; distance++, new_k = (new_k + 1) % new_size) |
| 511 | { |
| 512 | unsigned long other_hash = new_entries[new_k].hash; |
| 513 | |
| 514 | if (!other_hash) |
| 515 | /* Found an empty entry. */ |
| 516 | break; |
| 517 | |
| 518 | /* Displace the entry if our distance is less, otherwise keep |
| 519 | looking. */ |
| 520 | if (entry_distance (other_hash, new_k, new_size) < distance) |
| 521 | { |
| 522 | rob_from_rich (table, new_k); |
| 523 | break; |
| 524 | } |
| 525 | } |
| 526 | |
| 527 | table->n_items++; |
| 528 | new_entries[new_k].hash = copy.hash; |
| 529 | new_entries[new_k].key = copy.key; |
| 530 | new_entries[new_k].value = copy.value; |
| 531 | |
| 532 | register_disappearing_links (&new_entries[new_k], |
| 533 | SCM_PACK (copy.key), SCM_PACK (copy.value), |
| 534 | table->kind); |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | /* Run after GC via do_vacuum_weak_table, this function runs over the |
| 539 | whole table, removing lost weak references, reshuffling the table as it |
| 540 | goes. It might resize the table if it reaps enough entries. */ |
| 541 | static void |
| 542 | vacuum_weak_table (scm_t_weak_table *table) |
| 543 | { |
| 544 | scm_t_weak_entry *entries = table->entries; |
| 545 | unsigned long size = table->size; |
| 546 | unsigned long k; |
| 547 | |
| 548 | for (k = 0; k < size; k++) |
| 549 | { |
| 550 | unsigned long hash = entries[k].hash; |
| 551 | |
| 552 | if (hash) |
| 553 | { |
| 554 | scm_t_weak_entry copy; |
| 555 | |
| 556 | copy_weak_entry (&entries[k], ©); |
| 557 | |
| 558 | if (!copy.key || !copy.value) |
| 559 | /* Lost weak reference; reshuffle. */ |
| 560 | { |
| 561 | give_to_poor (table, k); |
| 562 | table->n_items--; |
| 563 | } |
| 564 | } |
| 565 | } |
| 566 | |
| 567 | if (table->n_items < table->lower) |
| 568 | resize_table (table); |
| 569 | } |
| 570 | |
| 571 | |
| 572 | \f |
| 573 | |
| 574 | static SCM |
| 575 | weak_table_ref (scm_t_weak_table *table, unsigned long hash, |
| 576 | scm_t_table_predicate_fn pred, void *closure, |
| 577 | SCM dflt) |
| 578 | { |
| 579 | unsigned long k, distance, size; |
| 580 | scm_t_weak_entry *entries; |
| 581 | |
| 582 | size = table->size; |
| 583 | entries = table->entries; |
| 584 | |
| 585 | hash = (hash << 1) | 0x1; |
| 586 | k = hash_to_index (hash, size); |
| 587 | |
| 588 | for (distance = 0; distance < size; distance++, k = (k + 1) % size) |
| 589 | { |
| 590 | unsigned long other_hash; |
| 591 | |
| 592 | retry: |
| 593 | other_hash = entries[k].hash; |
| 594 | |
| 595 | if (!other_hash) |
| 596 | /* Not found. */ |
| 597 | return dflt; |
| 598 | |
| 599 | if (hash == other_hash) |
| 600 | { |
| 601 | scm_t_weak_entry copy; |
| 602 | |
| 603 | copy_weak_entry (&entries[k], ©); |
| 604 | |
| 605 | if (!copy.key || !copy.value) |
| 606 | /* Lost weak reference; reshuffle. */ |
| 607 | { |
| 608 | give_to_poor (table, k); |
| 609 | table->n_items--; |
| 610 | goto retry; |
| 611 | } |
| 612 | |
| 613 | if (pred (SCM_PACK (copy.key), SCM_PACK (copy.value), closure)) |
| 614 | /* Found. */ |
| 615 | return SCM_PACK (copy.value); |
| 616 | } |
| 617 | |
| 618 | /* If the entry's distance is less, our key is not in the table. */ |
| 619 | if (entry_distance (other_hash, k, size) < distance) |
| 620 | return dflt; |
| 621 | } |
| 622 | |
| 623 | /* If we got here, then we were unfortunate enough to loop through the |
| 624 | whole table. Shouldn't happen, but hey. */ |
| 625 | return dflt; |
| 626 | } |
| 627 | |
| 628 | |
| 629 | static void |
| 630 | weak_table_put_x (scm_t_weak_table *table, unsigned long hash, |
| 631 | scm_t_table_predicate_fn pred, void *closure, |
| 632 | SCM key, SCM value) |
| 633 | { |
| 634 | unsigned long k, distance, size; |
| 635 | scm_t_weak_entry *entries; |
| 636 | |
| 637 | size = table->size; |
| 638 | entries = table->entries; |
| 639 | |
| 640 | hash = (hash << 1) | 0x1; |
| 641 | k = hash_to_index (hash, size); |
| 642 | |
| 643 | for (distance = 0; ; distance++, k = (k + 1) % size) |
| 644 | { |
| 645 | unsigned long other_hash; |
| 646 | |
| 647 | retry: |
| 648 | other_hash = entries[k].hash; |
| 649 | |
| 650 | if (!other_hash) |
| 651 | /* Found an empty entry. */ |
| 652 | break; |
| 653 | |
| 654 | if (other_hash == hash) |
| 655 | { |
| 656 | scm_t_weak_entry copy; |
| 657 | |
| 658 | copy_weak_entry (&entries[k], ©); |
| 659 | |
| 660 | if (!copy.key || !copy.value) |
| 661 | /* Lost weak reference; reshuffle. */ |
| 662 | { |
| 663 | give_to_poor (table, k); |
| 664 | table->n_items--; |
| 665 | goto retry; |
| 666 | } |
| 667 | |
| 668 | if (pred (SCM_PACK (copy.key), SCM_PACK (copy.value), closure)) |
| 669 | /* Found an entry with this key. */ |
| 670 | break; |
| 671 | } |
| 672 | |
| 673 | if (table->n_items > table->upper) |
| 674 | /* Full table, time to resize. */ |
| 675 | { |
| 676 | resize_table (table); |
| 677 | return weak_table_put_x (table, hash >> 1, pred, closure, key, value); |
| 678 | } |
| 679 | |
| 680 | /* Displace the entry if our distance is less, otherwise keep |
| 681 | looking. */ |
| 682 | if (entry_distance (other_hash, k, size) < distance) |
| 683 | { |
| 684 | rob_from_rich (table, k); |
| 685 | break; |
| 686 | } |
| 687 | } |
| 688 | |
| 689 | if (entries[k].hash) |
| 690 | unregister_disappearing_links (&entries[k], table->kind); |
| 691 | else |
| 692 | table->n_items++; |
| 693 | |
| 694 | entries[k].hash = hash; |
| 695 | entries[k].key = SCM_UNPACK (key); |
| 696 | entries[k].value = SCM_UNPACK (value); |
| 697 | |
| 698 | register_disappearing_links (&entries[k], key, value, table->kind); |
| 699 | } |
| 700 | |
| 701 | |
| 702 | static void |
| 703 | weak_table_remove_x (scm_t_weak_table *table, unsigned long hash, |
| 704 | scm_t_table_predicate_fn pred, void *closure) |
| 705 | { |
| 706 | unsigned long k, distance, size; |
| 707 | scm_t_weak_entry *entries; |
| 708 | |
| 709 | size = table->size; |
| 710 | entries = table->entries; |
| 711 | |
| 712 | hash = (hash << 1) | 0x1; |
| 713 | k = hash_to_index (hash, size); |
| 714 | |
| 715 | for (distance = 0; distance < size; distance++, k = (k + 1) % size) |
| 716 | { |
| 717 | unsigned long other_hash; |
| 718 | |
| 719 | retry: |
| 720 | other_hash = entries[k].hash; |
| 721 | |
| 722 | if (!other_hash) |
| 723 | /* Not found. */ |
| 724 | return; |
| 725 | |
| 726 | if (other_hash == hash) |
| 727 | { |
| 728 | scm_t_weak_entry copy; |
| 729 | |
| 730 | copy_weak_entry (&entries[k], ©); |
| 731 | |
| 732 | if (!copy.key || !copy.value) |
| 733 | /* Lost weak reference; reshuffle. */ |
| 734 | { |
| 735 | give_to_poor (table, k); |
| 736 | table->n_items--; |
| 737 | goto retry; |
| 738 | } |
| 739 | |
| 740 | if (pred (SCM_PACK (copy.key), SCM_PACK (copy.value), closure)) |
| 741 | /* Found an entry with this key. */ |
| 742 | { |
| 743 | entries[k].hash = 0; |
| 744 | entries[k].key = 0; |
| 745 | entries[k].value = 0; |
| 746 | |
| 747 | unregister_disappearing_links (&entries[k], table->kind); |
| 748 | |
| 749 | if (--table->n_items < table->lower) |
| 750 | resize_table (table); |
| 751 | else |
| 752 | give_to_poor (table, k); |
| 753 | |
| 754 | return; |
| 755 | } |
| 756 | } |
| 757 | |
| 758 | /* If the entry's distance is less, our key is not in the table. */ |
| 759 | if (entry_distance (other_hash, k, size) < distance) |
| 760 | return; |
| 761 | } |
| 762 | } |
| 763 | |
| 764 | |
| 765 | \f |
| 766 | static SCM |
| 767 | make_weak_table (unsigned long k, scm_t_weak_table_kind kind) |
| 768 | { |
| 769 | scm_t_weak_table *table; |
| 770 | |
| 771 | int i = 0, n = k ? k : 31; |
| 772 | while (i + 1 < HASHTABLE_SIZE_N && n > hashtable_size[i]) |
| 773 | ++i; |
| 774 | n = hashtable_size[i]; |
| 775 | |
| 776 | table = scm_gc_malloc (sizeof (*table), "weak-table"); |
| 777 | table->entries = allocate_entries (n, kind); |
| 778 | table->kind = kind; |
| 779 | table->n_items = 0; |
| 780 | table->size = n; |
| 781 | table->lower = 0; |
| 782 | table->upper = 9 * n / 10; |
| 783 | table->size_index = i; |
| 784 | table->min_size_index = i; |
| 785 | scm_i_pthread_mutex_init (&table->lock, NULL); |
| 786 | |
| 787 | return scm_cell (scm_tc7_weak_table, (scm_t_bits)table); |
| 788 | } |
| 789 | |
| 790 | void |
| 791 | scm_i_weak_table_print (SCM exp, SCM port, scm_print_state *pstate) |
| 792 | { |
| 793 | scm_puts_unlocked ("#<", port); |
| 794 | scm_puts_unlocked ("weak-table ", port); |
| 795 | scm_uintprint (SCM_WEAK_TABLE (exp)->n_items, 10, port); |
| 796 | scm_putc_unlocked ('/', port); |
| 797 | scm_uintprint (SCM_WEAK_TABLE (exp)->size, 10, port); |
| 798 | scm_puts_unlocked (">", port); |
| 799 | } |
| 800 | |
| 801 | static void |
| 802 | do_vacuum_weak_table (SCM table) |
| 803 | { |
| 804 | scm_t_weak_table *t; |
| 805 | |
| 806 | t = SCM_WEAK_TABLE (table); |
| 807 | |
| 808 | /* Unlike weak sets, the weak table interface allows custom predicates |
| 809 | to call out to arbitrary Scheme. There are two ways that this code |
| 810 | can be re-entrant, then: calling weak hash procedures while in a |
| 811 | custom predicate, or via finalizers run explicitly by (gc) or in an |
| 812 | async (for non-threaded Guile). We add a restriction that |
| 813 | prohibits the first case, by convention. But since we can't |
| 814 | prohibit the second case, here we trylock instead of lock. Not so |
| 815 | nice. */ |
| 816 | if (scm_i_pthread_mutex_trylock (&t->lock) == 0) |
| 817 | { |
| 818 | vacuum_weak_table (t); |
| 819 | scm_i_pthread_mutex_unlock (&t->lock); |
| 820 | } |
| 821 | |
| 822 | return; |
| 823 | } |
| 824 | |
| 825 | SCM |
| 826 | scm_c_make_weak_table (unsigned long k, scm_t_weak_table_kind kind) |
| 827 | { |
| 828 | SCM ret; |
| 829 | |
| 830 | ret = make_weak_table (k, kind); |
| 831 | |
| 832 | scm_i_register_weak_gc_callback (ret, do_vacuum_weak_table); |
| 833 | |
| 834 | return ret; |
| 835 | } |
| 836 | |
| 837 | SCM |
| 838 | scm_weak_table_p (SCM obj) |
| 839 | { |
| 840 | return scm_from_bool (SCM_WEAK_TABLE_P (obj)); |
| 841 | } |
| 842 | |
| 843 | SCM |
| 844 | scm_c_weak_table_ref (SCM table, unsigned long raw_hash, |
| 845 | scm_t_table_predicate_fn pred, |
| 846 | void *closure, SCM dflt) |
| 847 | #define FUNC_NAME "weak-table-ref" |
| 848 | { |
| 849 | SCM ret; |
| 850 | scm_t_weak_table *t; |
| 851 | |
| 852 | SCM_VALIDATE_WEAK_TABLE (1, table); |
| 853 | |
| 854 | t = SCM_WEAK_TABLE (table); |
| 855 | |
| 856 | scm_i_pthread_mutex_lock (&t->lock); |
| 857 | |
| 858 | ret = weak_table_ref (t, raw_hash, pred, closure, dflt); |
| 859 | |
| 860 | scm_i_pthread_mutex_unlock (&t->lock); |
| 861 | |
| 862 | return ret; |
| 863 | } |
| 864 | #undef FUNC_NAME |
| 865 | |
| 866 | void |
| 867 | scm_c_weak_table_put_x (SCM table, unsigned long raw_hash, |
| 868 | scm_t_table_predicate_fn pred, |
| 869 | void *closure, SCM key, SCM value) |
| 870 | #define FUNC_NAME "weak-table-put!" |
| 871 | { |
| 872 | scm_t_weak_table *t; |
| 873 | |
| 874 | SCM_VALIDATE_WEAK_TABLE (1, table); |
| 875 | |
| 876 | t = SCM_WEAK_TABLE (table); |
| 877 | |
| 878 | scm_i_pthread_mutex_lock (&t->lock); |
| 879 | |
| 880 | weak_table_put_x (t, raw_hash, pred, closure, key, value); |
| 881 | |
| 882 | scm_i_pthread_mutex_unlock (&t->lock); |
| 883 | } |
| 884 | #undef FUNC_NAME |
| 885 | |
| 886 | void |
| 887 | scm_c_weak_table_remove_x (SCM table, unsigned long raw_hash, |
| 888 | scm_t_table_predicate_fn pred, |
| 889 | void *closure) |
| 890 | #define FUNC_NAME "weak-table-remove!" |
| 891 | { |
| 892 | scm_t_weak_table *t; |
| 893 | |
| 894 | SCM_VALIDATE_WEAK_TABLE (1, table); |
| 895 | |
| 896 | t = SCM_WEAK_TABLE (table); |
| 897 | |
| 898 | scm_i_pthread_mutex_lock (&t->lock); |
| 899 | |
| 900 | weak_table_remove_x (t, raw_hash, pred, closure); |
| 901 | |
| 902 | scm_i_pthread_mutex_unlock (&t->lock); |
| 903 | } |
| 904 | #undef FUNC_NAME |
| 905 | |
| 906 | static int |
| 907 | assq_predicate (SCM x, SCM y, void *closure) |
| 908 | { |
| 909 | return scm_is_eq (x, SCM_PACK_POINTER (closure)); |
| 910 | } |
| 911 | |
| 912 | SCM |
| 913 | scm_weak_table_refq (SCM table, SCM key, SCM dflt) |
| 914 | { |
| 915 | if (SCM_UNBNDP (dflt)) |
| 916 | dflt = SCM_BOOL_F; |
| 917 | |
| 918 | return scm_c_weak_table_ref (table, scm_ihashq (key, -1), |
| 919 | assq_predicate, SCM_UNPACK_POINTER (key), |
| 920 | dflt); |
| 921 | } |
| 922 | |
| 923 | void |
| 924 | scm_weak_table_putq_x (SCM table, SCM key, SCM value) |
| 925 | { |
| 926 | scm_c_weak_table_put_x (table, scm_ihashq (key, -1), |
| 927 | assq_predicate, SCM_UNPACK_POINTER (key), |
| 928 | key, value); |
| 929 | } |
| 930 | |
| 931 | void |
| 932 | scm_weak_table_remq_x (SCM table, SCM key) |
| 933 | { |
| 934 | scm_c_weak_table_remove_x (table, scm_ihashq (key, -1), |
| 935 | assq_predicate, SCM_UNPACK_POINTER (key)); |
| 936 | } |
| 937 | |
| 938 | void |
| 939 | scm_weak_table_clear_x (SCM table) |
| 940 | #define FUNC_NAME "weak-table-clear!" |
| 941 | { |
| 942 | scm_t_weak_table *t; |
| 943 | |
| 944 | SCM_VALIDATE_WEAK_TABLE (1, table); |
| 945 | |
| 946 | t = SCM_WEAK_TABLE (table); |
| 947 | |
| 948 | scm_i_pthread_mutex_lock (&t->lock); |
| 949 | |
| 950 | memset (t->entries, 0, sizeof (scm_t_weak_entry) * t->size); |
| 951 | t->n_items = 0; |
| 952 | |
| 953 | scm_i_pthread_mutex_unlock (&t->lock); |
| 954 | } |
| 955 | #undef FUNC_NAME |
| 956 | |
| 957 | SCM |
| 958 | scm_c_weak_table_fold (scm_t_table_fold_fn proc, void *closure, |
| 959 | SCM init, SCM table) |
| 960 | { |
| 961 | scm_t_weak_table *t; |
| 962 | scm_t_weak_entry *entries; |
| 963 | unsigned long k, size; |
| 964 | |
| 965 | t = SCM_WEAK_TABLE (table); |
| 966 | |
| 967 | scm_i_pthread_mutex_lock (&t->lock); |
| 968 | |
| 969 | size = t->size; |
| 970 | entries = t->entries; |
| 971 | |
| 972 | for (k = 0; k < size; k++) |
| 973 | { |
| 974 | if (entries[k].hash) |
| 975 | { |
| 976 | scm_t_weak_entry copy; |
| 977 | |
| 978 | copy_weak_entry (&entries[k], ©); |
| 979 | |
| 980 | if (copy.key && copy.value) |
| 981 | { |
| 982 | /* Release table lock while we call the function. */ |
| 983 | scm_i_pthread_mutex_unlock (&t->lock); |
| 984 | init = proc (closure, |
| 985 | SCM_PACK (copy.key), SCM_PACK (copy.value), |
| 986 | init); |
| 987 | scm_i_pthread_mutex_lock (&t->lock); |
| 988 | } |
| 989 | } |
| 990 | } |
| 991 | |
| 992 | scm_i_pthread_mutex_unlock (&t->lock); |
| 993 | |
| 994 | return init; |
| 995 | } |
| 996 | |
| 997 | static SCM |
| 998 | fold_trampoline (void *closure, SCM k, SCM v, SCM init) |
| 999 | { |
| 1000 | return scm_call_3 (SCM_PACK_POINTER (closure), k, v, init); |
| 1001 | } |
| 1002 | |
| 1003 | SCM |
| 1004 | scm_weak_table_fold (SCM proc, SCM init, SCM table) |
| 1005 | #define FUNC_NAME "weak-table-fold" |
| 1006 | { |
| 1007 | SCM_VALIDATE_WEAK_TABLE (3, table); |
| 1008 | SCM_VALIDATE_PROC (1, proc); |
| 1009 | |
| 1010 | return scm_c_weak_table_fold (fold_trampoline, SCM_UNPACK_POINTER (proc), init, table); |
| 1011 | } |
| 1012 | #undef FUNC_NAME |
| 1013 | |
| 1014 | static SCM |
| 1015 | for_each_trampoline (void *closure, SCM k, SCM v, SCM seed) |
| 1016 | { |
| 1017 | scm_call_2 (SCM_PACK_POINTER (closure), k, v); |
| 1018 | return seed; |
| 1019 | } |
| 1020 | |
| 1021 | void |
| 1022 | scm_weak_table_for_each (SCM proc, SCM table) |
| 1023 | #define FUNC_NAME "weak-table-for-each" |
| 1024 | { |
| 1025 | SCM_VALIDATE_WEAK_TABLE (2, table); |
| 1026 | SCM_VALIDATE_PROC (1, proc); |
| 1027 | |
| 1028 | scm_c_weak_table_fold (for_each_trampoline, SCM_UNPACK_POINTER (proc), SCM_BOOL_F, table); |
| 1029 | } |
| 1030 | #undef FUNC_NAME |
| 1031 | |
| 1032 | static SCM |
| 1033 | map_trampoline (void *closure, SCM k, SCM v, SCM seed) |
| 1034 | { |
| 1035 | return scm_cons (scm_call_2 (SCM_PACK_POINTER (closure), k, v), seed); |
| 1036 | } |
| 1037 | |
| 1038 | SCM |
| 1039 | scm_weak_table_map_to_list (SCM proc, SCM table) |
| 1040 | #define FUNC_NAME "weak-table-map->list" |
| 1041 | { |
| 1042 | SCM_VALIDATE_WEAK_TABLE (2, table); |
| 1043 | SCM_VALIDATE_PROC (1, proc); |
| 1044 | |
| 1045 | return scm_c_weak_table_fold (map_trampoline, SCM_UNPACK_POINTER (proc), SCM_EOL, table); |
| 1046 | } |
| 1047 | #undef FUNC_NAME |
| 1048 | |
| 1049 | |
| 1050 | \f |
| 1051 | |
| 1052 | /* Legacy interface. */ |
| 1053 | |
| 1054 | SCM_DEFINE (scm_make_weak_key_hash_table, "make-weak-key-hash-table", 0, 1, 0, |
| 1055 | (SCM n), |
| 1056 | "@deffnx {Scheme Procedure} make-weak-value-hash-table size\n" |
| 1057 | "@deffnx {Scheme Procedure} make-doubly-weak-hash-table size\n" |
| 1058 | "Return a weak hash table with @var{size} buckets.\n" |
| 1059 | "\n" |
| 1060 | "You can modify weak hash tables in exactly the same way you\n" |
| 1061 | "would modify regular hash tables. (@pxref{Hash Tables})") |
| 1062 | #define FUNC_NAME s_scm_make_weak_key_hash_table |
| 1063 | { |
| 1064 | return scm_c_make_weak_table (SCM_UNBNDP (n) ? 0 : scm_to_ulong (n), |
| 1065 | SCM_WEAK_TABLE_KIND_KEY); |
| 1066 | } |
| 1067 | #undef FUNC_NAME |
| 1068 | |
| 1069 | |
| 1070 | SCM_DEFINE (scm_make_weak_value_hash_table, "make-weak-value-hash-table", 0, 1, 0, |
| 1071 | (SCM n), |
| 1072 | "Return a hash table with weak values with @var{size} buckets.\n" |
| 1073 | "(@pxref{Hash Tables})") |
| 1074 | #define FUNC_NAME s_scm_make_weak_value_hash_table |
| 1075 | { |
| 1076 | return scm_c_make_weak_table (SCM_UNBNDP (n) ? 0 : scm_to_ulong (n), |
| 1077 | SCM_WEAK_TABLE_KIND_VALUE); |
| 1078 | } |
| 1079 | #undef FUNC_NAME |
| 1080 | |
| 1081 | |
| 1082 | SCM_DEFINE (scm_make_doubly_weak_hash_table, "make-doubly-weak-hash-table", 0, 1, 0, |
| 1083 | (SCM n), |
| 1084 | "Return a hash table with weak keys and values with @var{size}\n" |
| 1085 | "buckets. (@pxref{Hash Tables})") |
| 1086 | #define FUNC_NAME s_scm_make_doubly_weak_hash_table |
| 1087 | { |
| 1088 | return scm_c_make_weak_table (SCM_UNBNDP (n) ? 0 : scm_to_ulong (n), |
| 1089 | SCM_WEAK_TABLE_KIND_BOTH); |
| 1090 | } |
| 1091 | #undef FUNC_NAME |
| 1092 | |
| 1093 | |
| 1094 | SCM_DEFINE (scm_weak_key_hash_table_p, "weak-key-hash-table?", 1, 0, 0, |
| 1095 | (SCM obj), |
| 1096 | "@deffnx {Scheme Procedure} weak-value-hash-table? obj\n" |
| 1097 | "@deffnx {Scheme Procedure} doubly-weak-hash-table? obj\n" |
| 1098 | "Return @code{#t} if @var{obj} is the specified weak hash\n" |
| 1099 | "table. Note that a doubly weak hash table is neither a weak key\n" |
| 1100 | "nor a weak value hash table.") |
| 1101 | #define FUNC_NAME s_scm_weak_key_hash_table_p |
| 1102 | { |
| 1103 | return scm_from_bool (SCM_WEAK_TABLE_P (obj) && |
| 1104 | SCM_WEAK_TABLE (obj)->kind == SCM_WEAK_TABLE_KIND_KEY); |
| 1105 | } |
| 1106 | #undef FUNC_NAME |
| 1107 | |
| 1108 | |
| 1109 | SCM_DEFINE (scm_weak_value_hash_table_p, "weak-value-hash-table?", 1, 0, 0, |
| 1110 | (SCM obj), |
| 1111 | "Return @code{#t} if @var{obj} is a weak value hash table.") |
| 1112 | #define FUNC_NAME s_scm_weak_value_hash_table_p |
| 1113 | { |
| 1114 | return scm_from_bool (SCM_WEAK_TABLE_P (obj) && |
| 1115 | SCM_WEAK_TABLE (obj)->kind == SCM_WEAK_TABLE_KIND_VALUE); |
| 1116 | } |
| 1117 | #undef FUNC_NAME |
| 1118 | |
| 1119 | |
| 1120 | SCM_DEFINE (scm_doubly_weak_hash_table_p, "doubly-weak-hash-table?", 1, 0, 0, |
| 1121 | (SCM obj), |
| 1122 | "Return @code{#t} if @var{obj} is a doubly weak hash table.") |
| 1123 | #define FUNC_NAME s_scm_doubly_weak_hash_table_p |
| 1124 | { |
| 1125 | return scm_from_bool (SCM_WEAK_TABLE_P (obj) && |
| 1126 | SCM_WEAK_TABLE (obj)->kind == SCM_WEAK_TABLE_KIND_BOTH); |
| 1127 | } |
| 1128 | #undef FUNC_NAME |
| 1129 | |
| 1130 | |
| 1131 | |
| 1132 | \f |
| 1133 | |
| 1134 | void |
| 1135 | scm_weak_table_prehistory (void) |
| 1136 | { |
| 1137 | weak_key_gc_kind = |
| 1138 | GC_new_kind (GC_new_free_list (), |
| 1139 | GC_MAKE_PROC (GC_new_proc (mark_weak_key_table), 0), |
| 1140 | 0, 0); |
| 1141 | weak_value_gc_kind = |
| 1142 | GC_new_kind (GC_new_free_list (), |
| 1143 | GC_MAKE_PROC (GC_new_proc (mark_weak_value_table), 0), |
| 1144 | 0, 0); |
| 1145 | } |
| 1146 | |
| 1147 | void |
| 1148 | scm_init_weak_table () |
| 1149 | { |
| 1150 | #include "libguile/weak-table.x" |
| 1151 | } |
| 1152 | |
| 1153 | /* |
| 1154 | Local Variables: |
| 1155 | c-file-style: "gnu" |
| 1156 | End: |
| 1157 | */ |