258
|
1
|
|
2 /*
|
|
3 * Copyright (C) Igor Sysoev
|
|
4 */
|
|
5
|
|
6 #include <ngx_config.h>
|
|
7 #include <ngx_core.h>
|
|
8
|
|
9 /*
|
|
10
|
|
11 12
|
|
12 2048 2 11
|
|
13 1024 4 10
|
|
14 512 8 9
|
|
15 256 16 8
|
|
16
|
|
17 128 32 4 32 7
|
|
18
|
|
19 64 64 8 63 6 1
|
|
20 32 128 16 127 5 1
|
|
21 16 256 32 254 4 2
|
|
22 8 512 64 504 3 8
|
|
23
|
|
24 */
|
|
25
|
|
26
|
|
27 #define NGX_SLAB_PAGE_MASK 3
|
|
28 #define NGX_SLAB_PAGE 0
|
|
29 #define NGX_SLAB_BIG 1
|
|
30 #define NGX_SLAB_EXACT 2
|
|
31 #define NGX_SLAB_SMALL 3
|
|
32
|
|
33 #if (NGX_PTR_SIZE == 4)
|
|
34
|
|
35 #define NGX_SLAB_PAGE_FREE 0
|
|
36 #define NGX_SLAB_PAGE_BUSY 0xffffffff
|
|
37 #define NGX_SLAB_PAGE_START 0x80000000
|
|
38
|
|
39 #define NGX_SLAB_SHIFT_MASK 0x0000000f
|
|
40 #define NGX_SLAB_MAP_MASK 0xffff0000
|
|
41 #define NGX_SLAB_MAP_SHIFT 16
|
|
42
|
|
43 #define NGX_SLAB_BUSY 0xffffffff
|
|
44
|
|
45 #else /* (NGX_PTR_SIZE == 8) */
|
|
46
|
|
47 #define NGX_SLAB_PAGE_FREE 0
|
|
48 #define NGX_SLAB_PAGE_BUSY 0xffffffffffffffff
|
|
49 #define NGX_SLAB_PAGE_START 0x8000000000000000
|
|
50
|
|
51 #define NGX_SLAB_SHIFT_MASK 0x000000000000000f
|
|
52 #define NGX_SLAB_MAP_MASK 0xffffffff00000000
|
|
53 #define NGX_SLAB_MAP_SHIFT 32
|
|
54
|
|
55 #define NGX_SLAB_BUSY 0xffffffffffffffff
|
|
56
|
|
57 #endif
|
|
58
|
|
59
|
|
60 #if (NGX_DEBUG_MALLOC)
|
|
61 #define ngx_slab_junk(p, size) ngx_memset(p, 0xD0, size)
|
|
62 #else
|
|
63 #define ngx_slab_junk(p, size)
|
|
64 #endif
|
|
65
|
|
66 static ngx_slab_page_t *ngx_slab_alloc_pages(ngx_slab_pool_t *pool,
|
|
67 ngx_uint_t pages);
|
|
68 static void ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
|
|
69 ngx_uint_t pages);
|
|
70
|
|
71
|
|
72 static ngx_uint_t ngx_slab_max_size;
|
|
73 static ngx_uint_t ngx_slab_exact_size;
|
|
74 static ngx_uint_t ngx_slab_exact_shift;
|
|
75
|
|
76
|
|
77 void
|
|
78 ngx_slab_init(ngx_slab_pool_t *pool)
|
|
79 {
|
|
80 u_char *p;
|
|
81 size_t size;
|
|
82 ngx_int_t m;
|
|
83 ngx_uint_t i, n, pages;
|
|
84 ngx_slab_page_t *slots;
|
|
85
|
|
86 /* STUB */
|
|
87 if (ngx_slab_max_size == 0) {
|
|
88 ngx_slab_max_size = ngx_pagesize / 2;
|
|
89 ngx_slab_exact_size = ngx_pagesize / (8 * sizeof(uintptr_t));
|
|
90 for (n = ngx_slab_exact_size; n >>= 1; ngx_slab_exact_shift++) {
|
|
91 /* void */
|
|
92 }
|
|
93 }
|
|
94 /**/
|
|
95
|
|
96 pool->min_size = 1 << pool->min_shift;
|
|
97
|
|
98 p = (u_char *) pool + sizeof(ngx_slab_pool_t);
|
|
99 size = pool->end - p;
|
|
100
|
|
101 ngx_slab_junk(p, size);
|
|
102
|
|
103 slots = (ngx_slab_page_t *) p;
|
|
104 n = ngx_pagesize_shift - pool->min_shift;
|
|
105
|
|
106 for (i = 0; i < n; i++) {
|
|
107 slots[i].slab = 0;
|
|
108 slots[i].next = &slots[i];
|
|
109 slots[i].prev = 0;
|
|
110 }
|
|
111
|
|
112 p += n * sizeof(ngx_slab_page_t);
|
|
113
|
|
114 /* STUB: possible overflow on 64-bit platform */
|
|
115 pages = (ngx_uint_t) ((uint64_t) size * ngx_pagesize
|
|
116 / (ngx_pagesize + sizeof(ngx_slab_page_t))
|
|
117 / ngx_pagesize);
|
|
118
|
|
119 ngx_memzero(p, pages * sizeof(ngx_slab_page_t));
|
|
120
|
|
121 pool->pages = (ngx_slab_page_t *) p;
|
|
122
|
|
123 pool->free.prev = 0;
|
|
124 pool->free.next = (ngx_slab_page_t *) p;
|
|
125
|
|
126 pool->pages->slab = pages;
|
|
127 pool->pages->next = &pool->free;
|
|
128 pool->pages->prev = (uintptr_t) &pool->free;
|
|
129
|
|
130 pool->start = (u_char *)
|
274
|
131 ngx_align_ptr((uintptr_t) p + pages * sizeof(ngx_slab_page_t),
|
258
|
132 ngx_pagesize);
|
|
133
|
|
134 m = pages - (pool->end - pool->start) / ngx_pagesize;
|
|
135 if (m > 0) {
|
|
136 pages -= m;
|
|
137 pool->pages->slab = pages;
|
|
138 }
|
|
139
|
|
140 #if 0
|
|
141 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "slab: %p, %p, %ui, %d",
|
|
142 pool, pool->start, pages,
|
|
143 (pool->end - pool->start) / ngx_pagesize - pages);
|
|
144 #endif
|
|
145 }
|
|
146
|
|
147
|
|
148 void *
|
|
149 ngx_slab_alloc(ngx_slab_pool_t *pool, size_t size)
|
|
150 {
|
272
|
151 void *p;
|
|
152
|
|
153 ngx_shmtx_lock(&pool->mutex);
|
|
154
|
|
155 p = ngx_slab_alloc_locked(pool, size);
|
|
156
|
|
157 ngx_shmtx_unlock(&pool->mutex);
|
|
158
|
|
159 return p;
|
|
160 }
|
|
161
|
|
162
|
|
163 void *
|
|
164 ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
|
|
165 {
|
258
|
166 size_t s;
|
260
|
167 uintptr_t p, n, m, mask, *bitmap;
|
|
168 ngx_uint_t i, slot, shift, map;
|
258
|
169 ngx_slab_page_t *page, *prev, *slots;
|
|
170
|
272
|
171 if (size >= ngx_slab_max_size) {
|
258
|
172
|
272
|
173 ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
|
|
174 "slab alloc: %uz", size);
|
|
175
|
258
|
176 page = ngx_slab_alloc_pages(pool, (size + ngx_pagesize - 1)
|
|
177 >> ngx_pagesize_shift);
|
|
178 if (page) {
|
|
179 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
180 p += (uintptr_t) pool->start;
|
|
181
|
|
182 } else {
|
|
183 p = 0;
|
|
184 }
|
|
185
|
|
186 goto done;
|
|
187 }
|
|
188
|
|
189 if (size > pool->min_size) {
|
|
190 shift = 1;
|
|
191 for (s = size - 1; s >>= 1; shift++) { /* void */ }
|
|
192 slot = shift - pool->min_shift;
|
|
193
|
|
194 } else {
|
|
195 size = pool->min_size;
|
|
196 shift = pool->min_shift;
|
|
197 slot = 0;
|
|
198 }
|
|
199
|
|
200 ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
|
|
201 "slab alloc: %uz slot: %ui", size, slot);
|
|
202
|
|
203 slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t));
|
|
204 page = slots[slot].next;
|
|
205
|
|
206 if (page->next != page) {
|
|
207
|
272
|
208 if (shift < ngx_slab_exact_shift) {
|
258
|
209
|
|
210 do {
|
|
211 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
212 bitmap = (uintptr_t *) (pool->start + p);
|
|
213
|
|
214 map = (1 << (ngx_pagesize_shift - shift))
|
|
215 / (sizeof(uintptr_t) * 8);
|
|
216
|
|
217 for (n = 0; n < map; n++) {
|
|
218
|
|
219 if (bitmap[n] != NGX_SLAB_BUSY) {
|
|
220
|
|
221 for (m = 1, i = 0; m; m <<= 1, i++) {
|
|
222 if ((bitmap[n] & m)) {
|
|
223 continue;
|
|
224 }
|
|
225
|
|
226 bitmap[n] |= m;
|
272
|
227
|
|
228 i = ((n * sizeof(uintptr_t) * 8) << shift)
|
|
229 + (i << shift);
|
258
|
230
|
|
231 if (bitmap[n] == NGX_SLAB_BUSY) {
|
|
232 for (n = n + 1; n < map; n++) {
|
|
233 if (bitmap[n] != NGX_SLAB_BUSY) {
|
|
234 p = (uintptr_t) bitmap + i;
|
|
235
|
|
236 goto done;
|
|
237 }
|
|
238 }
|
|
239
|
|
240 prev = (ngx_slab_page_t *)
|
|
241 (page->prev & ~NGX_SLAB_PAGE_MASK);
|
|
242 prev->next = page->next;
|
|
243 page->next->prev = page->prev;
|
|
244
|
|
245 page->next = NULL;
|
|
246 page->prev = NGX_SLAB_SMALL;
|
|
247 }
|
|
248
|
|
249 p = (uintptr_t) bitmap + i;
|
|
250
|
|
251 goto done;
|
|
252 }
|
|
253 }
|
|
254 }
|
|
255
|
|
256 page = page->next;
|
|
257
|
|
258 } while (page);
|
|
259
|
272
|
260 } else if (shift == ngx_slab_exact_shift) {
|
258
|
261
|
|
262 do {
|
|
263 if (page->slab != NGX_SLAB_BUSY) {
|
|
264
|
|
265 for (m = 1, i = 0; m; m <<= 1, i++) {
|
|
266 if ((page->slab & m)) {
|
|
267 continue;
|
|
268 }
|
|
269
|
|
270 page->slab |= m;
|
|
271
|
|
272 if (page->slab == NGX_SLAB_BUSY) {
|
|
273 prev = (ngx_slab_page_t *)
|
|
274 (page->prev & ~NGX_SLAB_PAGE_MASK);
|
|
275 prev->next = page->next;
|
|
276 page->next->prev = page->prev;
|
|
277
|
|
278 page->next = NULL;
|
|
279 page->prev = NGX_SLAB_EXACT;
|
|
280 }
|
|
281
|
|
282 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
283 p += i << shift;
|
|
284 p += (uintptr_t) pool->start;
|
|
285
|
|
286 goto done;
|
|
287 }
|
|
288 }
|
|
289
|
|
290 page = page->next;
|
|
291
|
|
292 } while (page);
|
|
293
|
272
|
294 } else { /* shift > ngx_slab_exact_shift */
|
258
|
295
|
|
296 n = ngx_pagesize_shift - (page->slab & NGX_SLAB_SHIFT_MASK);
|
|
297 n = 1 << n;
|
274
|
298 n = ((uintptr_t) 1 << n) - 1;
|
258
|
299 mask = n << NGX_SLAB_MAP_SHIFT;
|
|
300
|
|
301 do {
|
|
302 if ((page->slab & NGX_SLAB_MAP_MASK) != mask) {
|
|
303
|
260
|
304 for (m = (uintptr_t) 1 << NGX_SLAB_MAP_SHIFT, i = 0;
|
258
|
305 m & mask;
|
|
306 m <<= 1, i++)
|
|
307 {
|
|
308 if ((page->slab & m)) {
|
|
309 continue;
|
|
310 }
|
|
311
|
|
312 page->slab |= m;
|
|
313
|
|
314 if ((page->slab & NGX_SLAB_MAP_MASK) == mask) {
|
|
315 prev = (ngx_slab_page_t *)
|
|
316 (page->prev & ~NGX_SLAB_PAGE_MASK);
|
|
317 prev->next = page->next;
|
|
318 page->next->prev = page->prev;
|
|
319
|
|
320 page->next = NULL;
|
|
321 page->prev = NGX_SLAB_BIG;
|
|
322 }
|
|
323
|
|
324 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
325 p += i << shift;
|
|
326 p += (uintptr_t) pool->start;
|
|
327
|
|
328 goto done;
|
|
329 }
|
|
330 }
|
|
331
|
|
332 page = page->next;
|
|
333
|
|
334 } while (page);
|
|
335 }
|
|
336 }
|
|
337
|
|
338 page = ngx_slab_alloc_pages(pool, 1);
|
|
339
|
|
340 if (page) {
|
272
|
341 if (shift < ngx_slab_exact_shift) {
|
258
|
342 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
343 bitmap = (uintptr_t *) (pool->start + p);
|
|
344
|
|
345 s = 1 << shift;
|
|
346 n = (1 << (ngx_pagesize_shift - shift)) / 8 / s;
|
|
347
|
|
348 if (n == 0) {
|
|
349 n = 1;
|
|
350 }
|
|
351
|
|
352 bitmap[0] = (2 << n) - 1;
|
|
353
|
|
354 map = (1 << (ngx_pagesize_shift - shift)) / (sizeof(uintptr_t) * 8);
|
|
355
|
|
356 for (i = 1; i < map; i++) {
|
|
357 bitmap[i] = 0;
|
|
358 }
|
|
359
|
|
360 page->slab = shift;
|
|
361 page->next = &slots[slot];
|
|
362 page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_SMALL;
|
|
363
|
|
364 slots[slot].next = page;
|
|
365
|
|
366 p = ((page - pool->pages) << ngx_pagesize_shift) + s * n;
|
|
367 p += (uintptr_t) pool->start;
|
|
368
|
|
369 goto done;
|
|
370
|
272
|
371 } else if (shift == ngx_slab_exact_shift) {
|
258
|
372
|
|
373 page->slab = 1;
|
|
374 page->next = &slots[slot];
|
|
375 page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_EXACT;
|
|
376
|
|
377 slots[slot].next = page;
|
|
378
|
|
379 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
380 p += (uintptr_t) pool->start;
|
|
381
|
|
382 goto done;
|
|
383
|
272
|
384 } else { /* shift > ngx_slab_exact_shift */
|
258
|
385
|
260
|
386 page->slab = ((uintptr_t) 1 << NGX_SLAB_MAP_SHIFT) | shift;
|
258
|
387 page->next = &slots[slot];
|
|
388 page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_BIG;
|
|
389
|
|
390 slots[slot].next = page;
|
|
391
|
|
392 p = (page - pool->pages) << ngx_pagesize_shift;
|
|
393 p += (uintptr_t) pool->start;
|
|
394
|
|
395 goto done;
|
|
396 }
|
|
397 }
|
|
398
|
|
399 p = 0;
|
|
400
|
|
401 done:
|
|
402
|
|
403 ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab alloc: %p", p);
|
|
404
|
|
405 return (void *) p;
|
|
406 }
|
|
407
|
|
408
|
|
409 void
|
|
410 ngx_slab_free(ngx_slab_pool_t *pool, void *p)
|
|
411 {
|
272
|
412 ngx_shmtx_lock(&pool->mutex);
|
|
413
|
|
414 ngx_slab_free_locked(pool, p);
|
|
415
|
|
416 ngx_shmtx_unlock(&pool->mutex);
|
|
417 }
|
|
418
|
|
419
|
|
420 void
|
|
421 ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
|
|
422 {
|
258
|
423 size_t size;
|
274
|
424 uintptr_t slab, m, *bitmap;
|
|
425 ngx_uint_t n, type, slot, shift, map;
|
258
|
426 ngx_slab_page_t *slots, *page;
|
|
427
|
|
428 ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab free: %p", p);
|
|
429
|
|
430 if ((u_char *) p < pool->start || (u_char *) p > pool->end) {
|
|
431 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
|
|
432 "ngx_slab_free(): outside of pool");
|
|
433 goto fail;
|
|
434 }
|
|
435
|
|
436 n = ((u_char *) p - pool->start) >> ngx_pagesize_shift;
|
|
437 page = &pool->pages[n];
|
|
438 slab = page->slab;
|
|
439 type = page->prev & NGX_SLAB_PAGE_MASK;
|
|
440
|
|
441 switch (type) {
|
|
442
|
|
443 case NGX_SLAB_SMALL:
|
|
444
|
|
445 shift = slab & NGX_SLAB_SHIFT_MASK;
|
|
446 size = 1 << shift;
|
|
447
|
|
448 if ((uintptr_t) p & (size - 1)) {
|
|
449 goto wrong_chunk;
|
|
450 }
|
|
451
|
|
452 n = ((uintptr_t) p & (ngx_pagesize - 1)) >> shift;
|
274
|
453 m = (uintptr_t) 1 << (n & (sizeof(uintptr_t) * 8 - 1));
|
258
|
454 n /= (sizeof(uintptr_t) * 8);
|
|
455 bitmap = (uintptr_t *) ((uintptr_t) p & ~(ngx_pagesize - 1));
|
|
456
|
|
457 if (bitmap[n] & m) {
|
|
458
|
|
459 if (page->next == NULL) {
|
|
460 slots = (ngx_slab_page_t *)
|
|
461 ((u_char *) pool + sizeof(ngx_slab_pool_t));
|
|
462 slot = shift - pool->min_shift;
|
|
463
|
|
464 page->next = slots[slot].next;
|
|
465 slots[slot].next = page;
|
|
466
|
|
467 page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_SMALL;
|
|
468 page->next->prev = (uintptr_t) page | NGX_SLAB_SMALL;
|
|
469 }
|
|
470
|
|
471 bitmap[n] &= ~m;
|
|
472
|
|
473 n = (1 << (ngx_pagesize_shift - shift)) / 8 / (1 << shift);
|
|
474
|
|
475 if (n == 0) {
|
|
476 n = 1;
|
|
477 }
|
|
478
|
274
|
479 if (bitmap[0] & ~(((uintptr_t) 1 << n) - 1)) {
|
258
|
480 goto done;
|
|
481 }
|
|
482
|
|
483 map = (1 << (ngx_pagesize_shift - shift)) / (sizeof(uintptr_t) * 8);
|
|
484
|
|
485 for (n = 1; n < map; n++) {
|
|
486 if (bitmap[n]) {
|
|
487 goto done;
|
|
488 }
|
|
489 }
|
|
490
|
|
491 ngx_slab_free_pages(pool, page, 1);
|
|
492
|
|
493 goto done;
|
|
494 }
|
|
495
|
|
496 goto chunk_already_free;
|
|
497
|
|
498 case NGX_SLAB_EXACT:
|
|
499
|
274
|
500 m = (uintptr_t) 1 <<
|
|
501 (((uintptr_t) p & (ngx_pagesize - 1)) >> ngx_slab_exact_shift);
|
258
|
502 size = ngx_slab_exact_size;
|
|
503
|
|
504 if ((uintptr_t) p & (size - 1)) {
|
|
505 goto wrong_chunk;
|
|
506 }
|
|
507
|
|
508 if (slab & m) {
|
|
509 if (slab == NGX_SLAB_BUSY) {
|
|
510 slots = (ngx_slab_page_t *)
|
|
511 ((u_char *) pool + sizeof(ngx_slab_pool_t));
|
|
512 slot = ngx_slab_exact_shift - pool->min_shift;
|
|
513
|
|
514 page->next = slots[slot].next;
|
|
515 slots[slot].next = page;
|
|
516
|
|
517 page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_EXACT;
|
|
518 page->next->prev = (uintptr_t) page | NGX_SLAB_EXACT;
|
|
519 }
|
|
520
|
|
521 page->slab &= ~m;
|
|
522
|
|
523 if (page->slab) {
|
|
524 goto done;
|
|
525 }
|
|
526
|
|
527 ngx_slab_free_pages(pool, page, 1);
|
|
528
|
|
529 goto done;
|
|
530 }
|
|
531
|
|
532 goto chunk_already_free;
|
|
533
|
|
534 case NGX_SLAB_BIG:
|
|
535
|
|
536 shift = slab & NGX_SLAB_SHIFT_MASK;
|
|
537 size = 1 << shift;
|
|
538
|
|
539 if ((uintptr_t) p & (size - 1)) {
|
|
540 goto wrong_chunk;
|
|
541 }
|
|
542
|
274
|
543 m = (uintptr_t) 1 << ((((uintptr_t) p & (ngx_pagesize - 1)) >> shift)
|
|
544 + NGX_SLAB_MAP_SHIFT);
|
258
|
545
|
|
546 if (slab & m) {
|
|
547
|
|
548 if (page->next == NULL) {
|
|
549 slots = (ngx_slab_page_t *)
|
|
550 ((u_char *) pool + sizeof(ngx_slab_pool_t));
|
|
551 slot = shift - pool->min_shift;
|
|
552
|
|
553 page->next = slots[slot].next;
|
|
554 slots[slot].next = page;
|
|
555
|
|
556 page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_BIG;
|
|
557 page->next->prev = (uintptr_t) page | NGX_SLAB_BIG;
|
|
558 }
|
|
559
|
|
560 page->slab &= ~m;
|
|
561
|
|
562 if (page->slab & NGX_SLAB_MAP_MASK) {
|
|
563 goto done;
|
|
564 }
|
|
565
|
|
566 ngx_slab_free_pages(pool, page, 1);
|
|
567
|
|
568 goto done;
|
|
569 }
|
|
570
|
|
571 goto chunk_already_free;
|
|
572
|
|
573 case NGX_SLAB_PAGE:
|
|
574
|
|
575 if ((uintptr_t) p & (ngx_pagesize - 1)) {
|
|
576 goto wrong_chunk;
|
|
577 }
|
|
578
|
|
579 if (slab == NGX_SLAB_PAGE_FREE) {
|
|
580 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
|
|
581 "ngx_slab_free(): page is already free");
|
|
582 goto fail;
|
|
583 }
|
|
584
|
|
585 if (slab == NGX_SLAB_PAGE_BUSY) {
|
|
586 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
|
|
587 "ngx_slab_free(): pointer to wrong page");
|
|
588 goto fail;
|
|
589 }
|
|
590
|
|
591 n = ((u_char *) p - pool->start) >> ngx_pagesize_shift;
|
|
592 size = slab & ~NGX_SLAB_PAGE_START;
|
|
593
|
|
594 ngx_slab_free_pages(pool, &pool->pages[n], size);
|
|
595
|
|
596 size <<= ngx_pagesize_shift;
|
|
597
|
|
598 goto done;
|
|
599 }
|
|
600
|
|
601 /* not reached */
|
|
602
|
|
603 return;
|
|
604
|
|
605 done:
|
|
606
|
|
607 ngx_slab_junk(p, size);
|
|
608
|
|
609 return;
|
|
610
|
|
611 wrong_chunk:
|
|
612
|
|
613 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
|
|
614 "ngx_slab_free(): pointer to wrong chunk");
|
|
615
|
|
616 goto fail;
|
|
617
|
|
618 chunk_already_free:
|
|
619
|
|
620 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
|
|
621 "ngx_slab_free(): chunk is already free");
|
|
622
|
|
623 fail:
|
|
624
|
|
625 return;
|
|
626 }
|
|
627
|
|
628
|
|
629 static ngx_slab_page_t *
|
|
630 ngx_slab_alloc_pages(ngx_slab_pool_t *pool, ngx_uint_t pages)
|
|
631 {
|
|
632 ngx_slab_page_t *page, *p;
|
|
633
|
|
634 for (page = pool->free.next; page != &pool->free; page = page->next) {
|
|
635
|
|
636 if (page->slab >= pages) {
|
|
637
|
|
638 if (page->slab > pages) {
|
|
639 page[pages].slab = page->slab - pages;
|
|
640 page[pages].next = page->next;
|
|
641 page[pages].prev = page->prev;
|
|
642
|
|
643 p = (ngx_slab_page_t *) page->prev;
|
|
644 p->next = &page[pages];
|
|
645 page->next->prev = (uintptr_t) &page[pages];
|
|
646
|
|
647 } else {
|
|
648 p = (ngx_slab_page_t *) page->prev;
|
|
649 p->next = page->next;
|
|
650 page->next->prev = page->prev;
|
|
651 }
|
|
652
|
|
653 page->slab = pages | NGX_SLAB_PAGE_START;
|
|
654
|
|
655 #if (NGX_DEBUG)
|
|
656 page->next = NULL;
|
|
657 page->prev = NGX_SLAB_PAGE;
|
|
658 #endif
|
|
659
|
|
660 if (--pages == 0) {
|
|
661 return page;
|
|
662 }
|
|
663
|
|
664 for (p = page + 1; pages; pages--) {
|
|
665 p->slab = NGX_SLAB_PAGE_BUSY;
|
|
666 #if (NGX_DEBUG)
|
|
667 p->next = NULL;
|
|
668 p->prev = NGX_SLAB_PAGE;
|
|
669 #endif
|
|
670 p++;
|
|
671 }
|
|
672
|
|
673 return page;
|
|
674 }
|
|
675 }
|
|
676
|
|
677 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, NGX_ENOMEM,
|
|
678 "ngx_slab_alloc(): failed");
|
272
|
679
|
258
|
680 return NULL;
|
|
681 }
|
|
682
|
|
683
|
|
684 static void
|
|
685 ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
|
|
686 ngx_uint_t pages)
|
|
687 {
|
|
688 ngx_slab_page_t *prev;
|
|
689
|
|
690 page->slab = pages--;
|
|
691
|
|
692 if (pages) {
|
|
693 ngx_memzero(&page[1], pages * sizeof(ngx_slab_page_t));
|
|
694 }
|
|
695
|
272
|
696 if (page->next) {
|
|
697 prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK);
|
|
698 prev->next = page->next;
|
|
699 page->next->prev = page->prev;
|
|
700 }
|
258
|
701
|
272
|
702 page->prev = (uintptr_t) &pool->free;
|
258
|
703 page->next = pool->free.next;
|
272
|
704
|
|
705 page->next->prev = (uintptr_t) page;
|
|
706
|
258
|
707 pool->free.next = page;
|
|
708 }
|