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88e17b57 BE |
1 | /* Sparse Arrays for Objective C dispatch tables |
2 | Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* As a special exception, if you link this library with files | |
22 | compiled with GCC to produce an executable, this does not cause | |
23 | the resulting executable to be covered by the GNU General Public License. | |
24 | This exception does not however invalidate any other reasons why | |
25 | the executable file might be covered by the GNU General Public License. */ | |
26 | ||
bce1b489 BE |
27 | #include "sarray.h" |
28 | #include "runtime.h" | |
88e17b57 BE |
29 | #include <stdio.h> |
30 | #include "assert.h" | |
31 | ||
32 | int nbuckets = 0; /* !T:MUTEX */ | |
33 | int nindices = 0; /* !T:MUTEX */ | |
34 | int narrays = 0; /* !T:MUTEX */ | |
35 | int idxsize = 0; /* !T:MUTEX */ | |
36 | ||
37 | static void * first_free_data = NULL; /* !T:MUTEX */ | |
38 | ||
39 | #ifdef OBJC_SPARSE2 | |
40 | const char* __objc_sparse2_id = "2 level sparse indices"; | |
41 | #endif | |
42 | ||
43 | #ifdef OBJC_SPARSE3 | |
44 | const char* __objc_sparse3_id = "3 level sparse indices"; | |
45 | #endif | |
46 | ||
88e17b57 BE |
47 | /* This function removes any structures left over from free operations |
48 | that were not safe in a multi-threaded environment. */ | |
49 | void | |
50 | sarray_remove_garbage(void) | |
51 | { | |
52 | void **vp; | |
53 | void *np; | |
54 | ||
55 | objc_mutex_lock(__objc_runtime_mutex); | |
56 | ||
57 | vp = first_free_data; | |
58 | first_free_data = NULL; | |
59 | ||
60 | while (vp) { | |
61 | np = *vp; | |
62 | objc_free(vp); | |
63 | vp = np; | |
64 | } | |
65 | ||
66 | objc_mutex_unlock(__objc_runtime_mutex); | |
67 | } | |
68 | ||
69 | /* Free a block of dynamically allocated memory. If we are in multi-threaded | |
70 | mode, it is ok to free it. If not, we add it to the garbage heap to be | |
71 | freed later. */ | |
72 | ||
73 | static void | |
74 | sarray_free_garbage(void *vp) | |
75 | { | |
76 | objc_mutex_lock(__objc_runtime_mutex); | |
77 | ||
78 | if (__objc_runtime_threads_alive == 1) { | |
79 | objc_free(vp); | |
80 | if (first_free_data) | |
81 | sarray_remove_garbage(); | |
82 | } | |
83 | else { | |
84 | *(void **)vp = first_free_data; | |
85 | first_free_data = vp; | |
86 | } | |
87 | ||
88 | objc_mutex_unlock(__objc_runtime_mutex); | |
89 | } | |
90 | ||
91 | /* sarray_at_put : copies data in such a way as to be thread reader safe. */ | |
92 | void | |
93 | sarray_at_put(struct sarray* array, sidx index, void* element) | |
94 | { | |
95 | #ifdef OBJC_SPARSE3 | |
96 | struct sindex** the_index; | |
97 | struct sindex* new_index; | |
98 | #endif | |
99 | struct sbucket** the_bucket; | |
100 | struct sbucket* new_bucket; | |
101 | #ifdef OBJC_SPARSE3 | |
102 | size_t ioffset; | |
103 | #endif | |
104 | size_t boffset; | |
105 | size_t eoffset; | |
106 | #ifdef PRECOMPUTE_SELECTORS | |
107 | union sofftype xx; | |
108 | xx.idx = index; | |
109 | #ifdef OBJC_SPARSE3 | |
110 | ioffset = xx.off.ioffset; | |
111 | #endif | |
112 | boffset = xx.off.boffset; | |
113 | eoffset = xx.off.eoffset; | |
114 | #else /* not PRECOMPUTE_SELECTORS */ | |
115 | #ifdef OBJC_SPARSE3 | |
116 | ioffset = index/INDEX_CAPACITY; | |
117 | boffset = (index/BUCKET_SIZE)%INDEX_SIZE; | |
118 | eoffset = index%BUCKET_SIZE; | |
119 | #else | |
120 | boffset = index/BUCKET_SIZE; | |
121 | eoffset = index%BUCKET_SIZE; | |
122 | #endif | |
123 | #endif /* not PRECOMPUTE_SELECTORS */ | |
124 | ||
125 | assert(soffset_decode(index) < array->capacity); /* Range check */ | |
126 | ||
127 | #ifdef OBJC_SPARSE3 | |
128 | the_index = &(array->indices[ioffset]); | |
129 | the_bucket = &((*the_index)->buckets[boffset]); | |
130 | #else | |
131 | the_bucket = &(array->buckets[boffset]); | |
132 | #endif | |
133 | ||
134 | if ((*the_bucket)->elems[eoffset] == element) | |
135 | return; /* great! we just avoided a lazy copy */ | |
136 | ||
137 | #ifdef OBJC_SPARSE3 | |
138 | ||
139 | /* First, perform lazy copy/allocation of index if needed */ | |
140 | ||
141 | if ((*the_index) == array->empty_index) { | |
142 | ||
143 | /* The index was previously empty, allocate a new */ | |
144 | new_index = (struct sindex*)objc_malloc(sizeof(struct sindex)); | |
145 | memcpy(new_index, array->empty_index, sizeof(struct sindex)); | |
146 | new_index->version.version = array->version.version; | |
147 | *the_index = new_index; /* Prepared for install. */ | |
148 | the_bucket = &((*the_index)->buckets[boffset]); | |
149 | ||
150 | nindices += 1; | |
151 | } else if ((*the_index)->version.version != array->version.version) { | |
152 | ||
153 | /* This index must be lazy copied */ | |
154 | struct sindex* old_index = *the_index; | |
155 | new_index = (struct sindex*)objc_malloc(sizeof(struct sindex)); | |
156 | memcpy( new_index, old_index, sizeof(struct sindex)); | |
157 | new_index->version.version = array->version.version; | |
158 | *the_index = new_index; /* Prepared for install. */ | |
159 | the_bucket = &((*the_index)->buckets[boffset]); | |
160 | ||
161 | nindices += 1; | |
162 | } | |
163 | ||
164 | #endif /* OBJC_SPARSE3 */ | |
165 | ||
166 | /* next, perform lazy allocation/copy of the bucket if needed */ | |
167 | ||
168 | if ((*the_bucket) == array->empty_bucket) { | |
169 | ||
170 | /* The bucket was previously empty (or something like that), */ | |
171 | /* allocate a new. This is the effect of `lazy' allocation */ | |
172 | new_bucket = (struct sbucket*)objc_malloc(sizeof(struct sbucket)); | |
173 | memcpy((void *) new_bucket, (const void*)array->empty_bucket, | |
174 | sizeof(struct sbucket)); | |
175 | new_bucket->version.version = array->version.version; | |
176 | *the_bucket = new_bucket; /* Prepared for install. */ | |
177 | ||
178 | nbuckets += 1; | |
179 | ||
180 | } else if ((*the_bucket)->version.version != array->version.version) { | |
181 | ||
182 | /* Perform lazy copy. */ | |
183 | struct sbucket* old_bucket = *the_bucket; | |
184 | new_bucket = (struct sbucket*)objc_malloc(sizeof(struct sbucket)); | |
185 | memcpy( new_bucket, old_bucket, sizeof(struct sbucket)); | |
186 | new_bucket->version.version = array->version.version; | |
187 | *the_bucket = new_bucket; /* Prepared for install. */ | |
188 | ||
189 | nbuckets += 1; | |
190 | ||
191 | } | |
192 | (*the_bucket)->elems[eoffset] = element; | |
193 | } | |
194 | ||
195 | void | |
196 | sarray_at_put_safe(struct sarray* array, sidx index, void* element) | |
197 | { | |
198 | if(soffset_decode(index) >= array->capacity) | |
199 | sarray_realloc(array, soffset_decode(index)+1); | |
200 | sarray_at_put(array, index, element); | |
201 | } | |
202 | ||
203 | struct sarray* | |
204 | sarray_new (int size, void* default_element) | |
205 | { | |
206 | struct sarray* arr; | |
207 | #ifdef OBJC_SPARSE3 | |
208 | size_t num_indices = ((size-1)/(INDEX_CAPACITY))+1; | |
209 | struct sindex ** new_indices; | |
210 | #else /* OBJC_SPARSE2 */ | |
211 | size_t num_indices = ((size-1)/BUCKET_SIZE)+1; | |
212 | struct sbucket ** new_buckets; | |
213 | #endif | |
214 | int counter; | |
215 | ||
216 | assert(size > 0); | |
217 | ||
218 | /* Allocate core array */ | |
219 | arr = (struct sarray*) objc_malloc(sizeof(struct sarray)); | |
220 | arr->version.version = 0; | |
221 | ||
222 | /* Initialize members */ | |
223 | #ifdef OBJC_SPARSE3 | |
224 | arr->capacity = num_indices*INDEX_CAPACITY; | |
225 | new_indices = (struct sindex**) | |
226 | objc_malloc(sizeof(struct sindex*)*num_indices); | |
227 | ||
228 | arr->empty_index = (struct sindex*) objc_malloc(sizeof(struct sindex)); | |
229 | arr->empty_index->version.version = 0; | |
230 | ||
231 | narrays += 1; | |
232 | idxsize += num_indices; | |
233 | nindices += 1; | |
234 | ||
235 | #else /* OBJC_SPARSE2 */ | |
236 | arr->capacity = num_indices*BUCKET_SIZE; | |
237 | new_buckets = (struct sbucket**) | |
238 | objc_malloc(sizeof(struct sbucket*)*num_indices); | |
239 | ||
240 | narrays += 1; | |
241 | idxsize += num_indices; | |
242 | ||
243 | #endif | |
244 | ||
245 | arr->empty_bucket = (struct sbucket*) objc_malloc(sizeof(struct sbucket)); | |
246 | arr->empty_bucket->version.version = 0; | |
247 | ||
248 | nbuckets += 1; | |
249 | ||
250 | arr->ref_count = 1; | |
251 | arr->is_copy_of = (struct sarray*)0; | |
252 | ||
253 | for (counter=0; counter<BUCKET_SIZE; counter++) | |
254 | arr->empty_bucket->elems[counter] = default_element; | |
255 | ||
256 | #ifdef OBJC_SPARSE3 | |
257 | for (counter=0; counter<INDEX_SIZE; counter++) | |
258 | arr->empty_index->buckets[counter] = arr->empty_bucket; | |
259 | ||
260 | for (counter=0; counter<num_indices; counter++) | |
261 | new_indices[counter] = arr->empty_index; | |
262 | ||
263 | #else /* OBJC_SPARSE2 */ | |
264 | ||
265 | for (counter=0; counter<num_indices; counter++) | |
266 | new_buckets[counter] = arr->empty_bucket; | |
267 | ||
268 | #endif | |
269 | ||
270 | #ifdef OBJC_SPARSE3 | |
271 | arr->indices = new_indices; | |
272 | #else /* OBJC_SPARSE2 */ | |
273 | arr->buckets = new_buckets; | |
274 | #endif | |
275 | ||
276 | return arr; | |
277 | } | |
278 | \f | |
279 | ||
280 | /* Reallocate the sparse array to hold `newsize' entries | |
281 | Note: We really allocate and then free. We have to do this to ensure that | |
282 | any concurrent readers notice the update. */ | |
283 | ||
284 | void | |
285 | sarray_realloc(struct sarray* array, int newsize) | |
286 | { | |
287 | #ifdef OBJC_SPARSE3 | |
288 | size_t old_max_index = (array->capacity-1)/INDEX_CAPACITY; | |
289 | size_t new_max_index = ((newsize-1)/INDEX_CAPACITY); | |
290 | size_t rounded_size = (new_max_index+1)*INDEX_CAPACITY; | |
291 | ||
292 | struct sindex ** new_indices; | |
293 | struct sindex ** old_indices; | |
294 | ||
295 | #else /* OBJC_SPARSE2 */ | |
296 | size_t old_max_index = (array->capacity-1)/BUCKET_SIZE; | |
297 | size_t new_max_index = ((newsize-1)/BUCKET_SIZE); | |
298 | size_t rounded_size = (new_max_index+1)*BUCKET_SIZE; | |
299 | ||
300 | struct sbucket ** new_buckets; | |
301 | struct sbucket ** old_buckets; | |
302 | ||
303 | #endif | |
304 | ||
305 | int counter; | |
306 | ||
307 | assert(newsize > 0); | |
308 | ||
309 | /* The size is the same, just ignore the request */ | |
310 | if(rounded_size <= array->capacity) | |
311 | return; | |
312 | ||
313 | assert(array->ref_count == 1); /* stop if lazy copied... */ | |
314 | ||
315 | /* We are asked to extend the array -- allocate new bucket table, */ | |
316 | /* and insert empty_bucket in newly allocated places. */ | |
317 | if(rounded_size > array->capacity) | |
318 | { | |
319 | ||
320 | #ifdef OBJC_SPARSE3 | |
321 | new_max_index += 4; | |
322 | rounded_size = (new_max_index+1)*INDEX_CAPACITY; | |
323 | ||
324 | #else /* OBJC_SPARSE2 */ | |
325 | new_max_index += 4; | |
326 | rounded_size = (new_max_index+1)*BUCKET_SIZE; | |
327 | #endif | |
328 | ||
329 | /* update capacity */ | |
330 | array->capacity = rounded_size; | |
331 | ||
332 | #ifdef OBJC_SPARSE3 | |
333 | /* alloc to force re-read by any concurrent readers. */ | |
334 | old_indices = array->indices; | |
335 | new_indices = (struct sindex**) | |
336 | objc_malloc((new_max_index+1)*sizeof(struct sindex*)); | |
337 | #else /* OBJC_SPARSE2 */ | |
338 | old_buckets = array->buckets; | |
339 | new_buckets = (struct sbucket**) | |
340 | objc_malloc((new_max_index+1)*sizeof(struct sbucket*)); | |
341 | #endif | |
342 | ||
343 | /* copy buckets below old_max_index (they are still valid) */ | |
344 | for(counter = 0; counter <= old_max_index; counter++ ) { | |
345 | #ifdef OBJC_SPARSE3 | |
346 | new_indices[counter] = old_indices[counter]; | |
347 | #else /* OBJC_SPARSE2 */ | |
348 | new_buckets[counter] = old_buckets[counter]; | |
349 | #endif | |
350 | } | |
351 | ||
352 | #ifdef OBJC_SPARSE3 | |
353 | /* reset entries above old_max_index to empty_bucket */ | |
354 | for(counter = old_max_index+1; counter <= new_max_index; counter++) | |
355 | new_indices[counter] = array->empty_index; | |
356 | #else /* OBJC_SPARSE2 */ | |
357 | /* reset entries above old_max_index to empty_bucket */ | |
358 | for(counter = old_max_index+1; counter <= new_max_index; counter++) | |
359 | new_buckets[counter] = array->empty_bucket; | |
360 | #endif | |
361 | ||
362 | #ifdef OBJC_SPARSE3 | |
363 | /* install the new indices */ | |
364 | array->indices = new_indices; | |
365 | #else /* OBJC_SPARSE2 */ | |
366 | array->buckets = new_buckets; | |
367 | #endif | |
368 | ||
369 | #ifdef OBJC_SPARSE3 | |
370 | /* free the old indices */ | |
371 | sarray_free_garbage(old_indices); | |
372 | #else /* OBJC_SPARSE2 */ | |
373 | sarray_free_garbage(old_buckets); | |
374 | #endif | |
375 | ||
376 | idxsize += (new_max_index-old_max_index); | |
377 | return; | |
378 | } | |
379 | } | |
380 | \f | |
381 | ||
382 | /* Free a sparse array allocated with sarray_new */ | |
383 | ||
384 | void | |
385 | sarray_free(struct sarray* array) { | |
386 | ||
387 | #ifdef OBJC_SPARSE3 | |
388 | size_t old_max_index = (array->capacity-1)/INDEX_CAPACITY; | |
389 | struct sindex ** old_indices; | |
390 | #else | |
391 | size_t old_max_index = (array->capacity-1)/BUCKET_SIZE; | |
392 | struct sbucket ** old_buckets; | |
393 | #endif | |
394 | int counter = 0; | |
395 | ||
396 | assert(array->ref_count != 0); /* Freed multiple times!!! */ | |
397 | ||
398 | if(--(array->ref_count) != 0) /* There exists copies of me */ | |
399 | return; | |
400 | ||
401 | #ifdef OBJC_SPARSE3 | |
402 | old_indices = array->indices; | |
403 | #else | |
404 | old_buckets = array->buckets; | |
405 | #endif | |
406 | ||
407 | if((array->is_copy_of) && ((array->is_copy_of->ref_count - 1) == 0)) | |
408 | sarray_free(array->is_copy_of); | |
409 | ||
410 | /* Free all entries that do not point to empty_bucket */ | |
411 | for(counter = 0; counter <= old_max_index; counter++ ) { | |
412 | #ifdef OBJC_SPARSE3 | |
413 | struct sindex* idx = old_indices[counter]; | |
414 | if((idx != array->empty_index) && | |
415 | (idx->version.version == array->version.version)) { | |
416 | int c2; | |
417 | for(c2=0; c2<INDEX_SIZE; c2++) { | |
418 | struct sbucket* bkt = idx->buckets[c2]; | |
419 | if((bkt != array->empty_bucket) && | |
420 | (bkt->version.version == array->version.version)) | |
421 | { | |
422 | sarray_free_garbage(bkt); | |
423 | nbuckets -= 1; | |
424 | } | |
425 | } | |
426 | sarray_free_garbage(idx); | |
427 | nindices -= 1; | |
428 | } | |
429 | #else /* OBJC_SPARSE2 */ | |
430 | struct sbucket* bkt = array->buckets[counter]; | |
431 | if ((bkt != array->empty_bucket) && | |
432 | (bkt->version.version == array->version.version)) | |
433 | { | |
434 | sarray_free_garbage(bkt); | |
435 | nbuckets -= 1; | |
436 | } | |
437 | #endif | |
438 | } | |
439 | ||
440 | #ifdef OBJC_SPARSE3 | |
441 | /* free empty_index */ | |
442 | if(array->empty_index->version.version == array->version.version) { | |
443 | sarray_free_garbage(array->empty_index); | |
444 | nindices -= 1; | |
445 | } | |
446 | #endif | |
447 | ||
448 | /* free empty_bucket */ | |
449 | if(array->empty_bucket->version.version == array->version.version) { | |
450 | sarray_free_garbage(array->empty_bucket); | |
451 | nbuckets -= 1; | |
452 | } | |
453 | idxsize -= (old_max_index+1); | |
454 | narrays -= 1; | |
455 | ||
456 | #ifdef OBJC_SPARSE3 | |
457 | /* free bucket table */ | |
458 | sarray_free_garbage(array->indices); | |
459 | ||
460 | #else | |
461 | /* free bucket table */ | |
462 | sarray_free_garbage(array->buckets); | |
463 | ||
464 | #endif | |
465 | ||
466 | /* free array */ | |
467 | sarray_free_garbage(array); | |
468 | } | |
469 | ||
470 | /* This is a lazy copy. Only the core of the structure is actually */ | |
471 | /* copied. */ | |
472 | ||
473 | struct sarray* | |
474 | sarray_lazy_copy(struct sarray* oarr) | |
475 | { | |
476 | struct sarray* arr; | |
477 | ||
478 | #ifdef OBJC_SPARSE3 | |
479 | size_t num_indices = ((oarr->capacity-1)/INDEX_CAPACITY)+1; | |
480 | struct sindex ** new_indices; | |
481 | #else /* OBJC_SPARSE2 */ | |
482 | size_t num_indices = ((oarr->capacity-1)/BUCKET_SIZE)+1; | |
483 | struct sbucket ** new_buckets; | |
484 | #endif | |
485 | ||
486 | /* Allocate core array */ | |
487 | arr = (struct sarray*) objc_malloc(sizeof(struct sarray)); /* !!! */ | |
488 | arr->version.version = oarr->version.version + 1; | |
489 | #ifdef OBJC_SPARSE3 | |
490 | arr->empty_index = oarr->empty_index; | |
491 | #endif | |
492 | arr->empty_bucket = oarr->empty_bucket; | |
493 | arr->ref_count = 1; | |
494 | oarr->ref_count += 1; | |
495 | arr->is_copy_of = oarr; | |
496 | arr->capacity = oarr->capacity; | |
497 | ||
498 | #ifdef OBJC_SPARSE3 | |
499 | /* Copy bucket table */ | |
500 | new_indices = (struct sindex**) | |
501 | objc_malloc(sizeof(struct sindex*)*num_indices); | |
502 | memcpy( new_indices,oarr->indices, | |
503 | sizeof(struct sindex*)*num_indices); | |
504 | arr->indices = new_indices; | |
505 | #else | |
506 | /* Copy bucket table */ | |
507 | new_buckets = (struct sbucket**) | |
508 | objc_malloc(sizeof(struct sbucket*)*num_indices); | |
509 | memcpy( new_buckets,oarr->buckets, | |
510 | sizeof(struct sbucket*)*num_indices); | |
511 | arr->buckets = new_buckets; | |
512 | #endif | |
513 | ||
514 | idxsize += num_indices; | |
515 | narrays += 1; | |
516 | ||
517 | return arr; | |
518 | } |