1 | /*---------------------------------------------------------------------------- |
2 | Copyright (c) 2018-2020, Microsoft Research, Daan Leijen |
3 | This is free software; you can redistribute it and/or modify it under the |
4 | terms of the MIT license. A copy of the license can be found in the file |
5 | "LICENSE" at the root of this distribution. |
6 | -----------------------------------------------------------------------------*/ |
7 | |
8 | /* ----------------------------------------------------------- |
9 | Definition of page queues for each block size |
10 | ----------------------------------------------------------- */ |
11 | |
12 | #ifndef MI_IN_PAGE_C |
13 | #error "this file should be included from 'page.c'" |
14 | #endif |
15 | |
16 | /* ----------------------------------------------------------- |
17 | Minimal alignment in machine words (i.e. `sizeof(void*)`) |
18 | ----------------------------------------------------------- */ |
19 | |
20 | #if (MI_MAX_ALIGN_SIZE > 4*MI_INTPTR_SIZE) |
21 | #error "define alignment for more than 4x word size for this platform" |
22 | #elif (MI_MAX_ALIGN_SIZE > 2*MI_INTPTR_SIZE) |
23 | #define MI_ALIGN4W // 4 machine words minimal alignment |
24 | #elif (MI_MAX_ALIGN_SIZE > MI_INTPTR_SIZE) |
25 | #define MI_ALIGN2W // 2 machine words minimal alignment |
26 | #else |
27 | // ok, default alignment is 1 word |
28 | #endif |
29 | |
30 | |
31 | /* ----------------------------------------------------------- |
32 | Queue query |
33 | ----------------------------------------------------------- */ |
34 | |
35 | |
36 | static inline bool mi_page_queue_is_huge(const mi_page_queue_t* pq) { |
37 | return (pq->block_size == (MI_MEDIUM_OBJ_SIZE_MAX+sizeof(uintptr_t))); |
38 | } |
39 | |
40 | static inline bool mi_page_queue_is_full(const mi_page_queue_t* pq) { |
41 | return (pq->block_size == (MI_MEDIUM_OBJ_SIZE_MAX+(2*sizeof(uintptr_t)))); |
42 | } |
43 | |
44 | static inline bool mi_page_queue_is_special(const mi_page_queue_t* pq) { |
45 | return (pq->block_size > MI_MEDIUM_OBJ_SIZE_MAX); |
46 | } |
47 | |
48 | /* ----------------------------------------------------------- |
49 | Bins |
50 | ----------------------------------------------------------- */ |
51 | |
52 | // Return the bin for a given field size. |
53 | // Returns MI_BIN_HUGE if the size is too large. |
54 | // We use `wsize` for the size in "machine word sizes", |
55 | // i.e. byte size == `wsize*sizeof(void*)`. |
56 | static inline uint8_t mi_bin(size_t size) { |
57 | size_t wsize = _mi_wsize_from_size(size); |
58 | uint8_t bin; |
59 | if (wsize <= 1) { |
60 | bin = 1; |
61 | } |
62 | #if defined(MI_ALIGN4W) |
63 | else if (wsize <= 4) { |
64 | bin = (uint8_t)((wsize+1)&~1); // round to double word sizes |
65 | } |
66 | #elif defined(MI_ALIGN2W) |
67 | else if (wsize <= 8) { |
68 | bin = (uint8_t)((wsize+1)&~1); // round to double word sizes |
69 | } |
70 | #else |
71 | else if (wsize <= 8) { |
72 | bin = (uint8_t)wsize; |
73 | } |
74 | #endif |
75 | else if (wsize > MI_MEDIUM_OBJ_WSIZE_MAX) { |
76 | bin = MI_BIN_HUGE; |
77 | } |
78 | else { |
79 | #if defined(MI_ALIGN4W) |
80 | if (wsize <= 16) { wsize = (wsize+3)&~3; } // round to 4x word sizes |
81 | #endif |
82 | wsize--; |
83 | // find the highest bit |
84 | uint8_t b = (uint8_t)mi_bsr(wsize); // note: wsize != 0 |
85 | // and use the top 3 bits to determine the bin (~12.5% worst internal fragmentation). |
86 | // - adjust with 3 because we use do not round the first 8 sizes |
87 | // which each get an exact bin |
88 | bin = ((b << 2) + (uint8_t)((wsize >> (b - 2)) & 0x03)) - 3; |
89 | mi_assert_internal(bin < MI_BIN_HUGE); |
90 | } |
91 | mi_assert_internal(bin > 0 && bin <= MI_BIN_HUGE); |
92 | return bin; |
93 | } |
94 | |
95 | |
96 | |
97 | /* ----------------------------------------------------------- |
98 | Queue of pages with free blocks |
99 | ----------------------------------------------------------- */ |
100 | |
101 | uint8_t _mi_bin(size_t size) { |
102 | return mi_bin(size); |
103 | } |
104 | |
105 | size_t _mi_bin_size(uint8_t bin) { |
106 | return _mi_heap_empty.pages[bin].block_size; |
107 | } |
108 | |
109 | // Good size for allocation |
110 | size_t mi_good_size(size_t size) mi_attr_noexcept { |
111 | if (size <= MI_MEDIUM_OBJ_SIZE_MAX) { |
112 | return _mi_bin_size(mi_bin(size)); |
113 | } |
114 | else { |
115 | return _mi_align_up(size,_mi_os_page_size()); |
116 | } |
117 | } |
118 | |
119 | #if (MI_DEBUG>1) |
120 | static bool mi_page_queue_contains(mi_page_queue_t* queue, const mi_page_t* page) { |
121 | mi_assert_internal(page != NULL); |
122 | mi_page_t* list = queue->first; |
123 | while (list != NULL) { |
124 | mi_assert_internal(list->next == NULL || list->next->prev == list); |
125 | mi_assert_internal(list->prev == NULL || list->prev->next == list); |
126 | if (list == page) break; |
127 | list = list->next; |
128 | } |
129 | return (list == page); |
130 | } |
131 | |
132 | #endif |
133 | |
134 | #if (MI_DEBUG>1) |
135 | static bool mi_heap_contains_queue(const mi_heap_t* heap, const mi_page_queue_t* pq) { |
136 | return (pq >= &heap->pages[0] && pq <= &heap->pages[MI_BIN_FULL]); |
137 | } |
138 | #endif |
139 | |
140 | static mi_page_queue_t* mi_page_queue_of(const mi_page_t* page) { |
141 | uint8_t bin = (mi_page_is_in_full(page) ? MI_BIN_FULL : mi_bin(page->xblock_size)); |
142 | mi_heap_t* heap = mi_page_heap(page); |
143 | mi_assert_internal(heap != NULL && bin <= MI_BIN_FULL); |
144 | mi_page_queue_t* pq = &heap->pages[bin]; |
145 | mi_assert_internal(bin >= MI_BIN_HUGE || page->xblock_size == pq->block_size); |
146 | mi_assert_expensive(mi_page_queue_contains(pq, page)); |
147 | return pq; |
148 | } |
149 | |
150 | static mi_page_queue_t* mi_heap_page_queue_of(mi_heap_t* heap, const mi_page_t* page) { |
151 | uint8_t bin = (mi_page_is_in_full(page) ? MI_BIN_FULL : mi_bin(page->xblock_size)); |
152 | mi_assert_internal(bin <= MI_BIN_FULL); |
153 | mi_page_queue_t* pq = &heap->pages[bin]; |
154 | mi_assert_internal(mi_page_is_in_full(page) || page->xblock_size == pq->block_size); |
155 | return pq; |
156 | } |
157 | |
158 | // The current small page array is for efficiency and for each |
159 | // small size (up to 256) it points directly to the page for that |
160 | // size without having to compute the bin. This means when the |
161 | // current free page queue is updated for a small bin, we need to update a |
162 | // range of entries in `_mi_page_small_free`. |
163 | static inline void mi_heap_queue_first_update(mi_heap_t* heap, const mi_page_queue_t* pq) { |
164 | mi_assert_internal(mi_heap_contains_queue(heap,pq)); |
165 | size_t size = pq->block_size; |
166 | if (size > MI_SMALL_SIZE_MAX) return; |
167 | |
168 | mi_page_t* page = pq->first; |
169 | if (pq->first == NULL) page = (mi_page_t*)&_mi_page_empty; |
170 | |
171 | // find index in the right direct page array |
172 | size_t start; |
173 | size_t idx = _mi_wsize_from_size(size); |
174 | mi_page_t** pages_free = heap->pages_free_direct; |
175 | |
176 | if (pages_free[idx] == page) return; // already set |
177 | |
178 | // find start slot |
179 | if (idx<=1) { |
180 | start = 0; |
181 | } |
182 | else { |
183 | // find previous size; due to minimal alignment upto 3 previous bins may need to be skipped |
184 | uint8_t bin = mi_bin(size); |
185 | const mi_page_queue_t* prev = pq - 1; |
186 | while( bin == mi_bin(prev->block_size) && prev > &heap->pages[0]) { |
187 | prev--; |
188 | } |
189 | start = 1 + _mi_wsize_from_size(prev->block_size); |
190 | if (start > idx) start = idx; |
191 | } |
192 | |
193 | // set size range to the right page |
194 | mi_assert(start <= idx); |
195 | for (size_t sz = start; sz <= idx; sz++) { |
196 | pages_free[sz] = page; |
197 | } |
198 | } |
199 | |
200 | /* |
201 | static bool mi_page_queue_is_empty(mi_page_queue_t* queue) { |
202 | return (queue->first == NULL); |
203 | } |
204 | */ |
205 | |
206 | static void mi_page_queue_remove(mi_page_queue_t* queue, mi_page_t* page) { |
207 | mi_assert_internal(page != NULL); |
208 | mi_assert_expensive(mi_page_queue_contains(queue, page)); |
209 | mi_assert_internal(page->xblock_size == queue->block_size || (page->xblock_size > MI_MEDIUM_OBJ_SIZE_MAX && mi_page_queue_is_huge(queue)) || (mi_page_is_in_full(page) && mi_page_queue_is_full(queue))); |
210 | mi_heap_t* heap = mi_page_heap(page); |
211 | |
212 | if (page->prev != NULL) page->prev->next = page->next; |
213 | if (page->next != NULL) page->next->prev = page->prev; |
214 | if (page == queue->last) queue->last = page->prev; |
215 | if (page == queue->first) { |
216 | queue->first = page->next; |
217 | // update first |
218 | mi_assert_internal(mi_heap_contains_queue(heap, queue)); |
219 | mi_heap_queue_first_update(heap,queue); |
220 | } |
221 | heap->page_count--; |
222 | page->next = NULL; |
223 | page->prev = NULL; |
224 | // mi_atomic_store_ptr_release(mi_atomic_cast(void*, &page->heap), NULL); |
225 | mi_page_set_in_full(page,false); |
226 | } |
227 | |
228 | |
229 | static void mi_page_queue_push(mi_heap_t* heap, mi_page_queue_t* queue, mi_page_t* page) { |
230 | mi_assert_internal(mi_page_heap(page) == heap); |
231 | mi_assert_internal(!mi_page_queue_contains(queue, page)); |
232 | |
233 | mi_assert_internal(_mi_page_segment(page)->kind != MI_SEGMENT_HUGE); |
234 | mi_assert_internal(page->xblock_size == queue->block_size || |
235 | (page->xblock_size > MI_MEDIUM_OBJ_SIZE_MAX) || |
236 | (mi_page_is_in_full(page) && mi_page_queue_is_full(queue))); |
237 | |
238 | mi_page_set_in_full(page, mi_page_queue_is_full(queue)); |
239 | // mi_atomic_store_ptr_release(mi_atomic_cast(void*, &page->heap), heap); |
240 | page->next = queue->first; |
241 | page->prev = NULL; |
242 | if (queue->first != NULL) { |
243 | mi_assert_internal(queue->first->prev == NULL); |
244 | queue->first->prev = page; |
245 | queue->first = page; |
246 | } |
247 | else { |
248 | queue->first = queue->last = page; |
249 | } |
250 | |
251 | // update direct |
252 | mi_heap_queue_first_update(heap, queue); |
253 | heap->page_count++; |
254 | } |
255 | |
256 | |
257 | static void mi_page_queue_enqueue_from(mi_page_queue_t* to, mi_page_queue_t* from, mi_page_t* page) { |
258 | mi_assert_internal(page != NULL); |
259 | mi_assert_expensive(mi_page_queue_contains(from, page)); |
260 | mi_assert_expensive(!mi_page_queue_contains(to, page)); |
261 | |
262 | mi_assert_internal((page->xblock_size == to->block_size && page->xblock_size == from->block_size) || |
263 | (page->xblock_size == to->block_size && mi_page_queue_is_full(from)) || |
264 | (page->xblock_size == from->block_size && mi_page_queue_is_full(to)) || |
265 | (page->xblock_size > MI_LARGE_OBJ_SIZE_MAX && mi_page_queue_is_huge(to)) || |
266 | (page->xblock_size > MI_LARGE_OBJ_SIZE_MAX && mi_page_queue_is_full(to))); |
267 | |
268 | mi_heap_t* heap = mi_page_heap(page); |
269 | if (page->prev != NULL) page->prev->next = page->next; |
270 | if (page->next != NULL) page->next->prev = page->prev; |
271 | if (page == from->last) from->last = page->prev; |
272 | if (page == from->first) { |
273 | from->first = page->next; |
274 | // update first |
275 | mi_assert_internal(mi_heap_contains_queue(heap, from)); |
276 | mi_heap_queue_first_update(heap, from); |
277 | } |
278 | |
279 | page->prev = to->last; |
280 | page->next = NULL; |
281 | if (to->last != NULL) { |
282 | mi_assert_internal(heap == mi_page_heap(to->last)); |
283 | to->last->next = page; |
284 | to->last = page; |
285 | } |
286 | else { |
287 | to->first = page; |
288 | to->last = page; |
289 | mi_heap_queue_first_update(heap, to); |
290 | } |
291 | |
292 | mi_page_set_in_full(page, mi_page_queue_is_full(to)); |
293 | } |
294 | |
295 | // Only called from `mi_heap_absorb`. |
296 | size_t _mi_page_queue_append(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_queue_t* append) { |
297 | mi_assert_internal(mi_heap_contains_queue(heap,pq)); |
298 | mi_assert_internal(pq->block_size == append->block_size); |
299 | |
300 | if (append->first==NULL) return 0; |
301 | |
302 | // set append pages to new heap and count |
303 | size_t count = 0; |
304 | for (mi_page_t* page = append->first; page != NULL; page = page->next) { |
305 | // inline `mi_page_set_heap` to avoid wrong assertion during absorption; |
306 | // in this case it is ok to be delayed freeing since both "to" and "from" heap are still alive. |
307 | mi_atomic_store_release(&page->xheap, (uintptr_t)heap); |
308 | // set the flag to delayed free (not overriding NEVER_DELAYED_FREE) which has as a |
309 | // side effect that it spins until any DELAYED_FREEING is finished. This ensures |
310 | // that after appending only the new heap will be used for delayed free operations. |
311 | _mi_page_use_delayed_free(page, MI_USE_DELAYED_FREE, false); |
312 | count++; |
313 | } |
314 | |
315 | if (pq->last==NULL) { |
316 | // take over afresh |
317 | mi_assert_internal(pq->first==NULL); |
318 | pq->first = append->first; |
319 | pq->last = append->last; |
320 | mi_heap_queue_first_update(heap, pq); |
321 | } |
322 | else { |
323 | // append to end |
324 | mi_assert_internal(pq->last!=NULL); |
325 | mi_assert_internal(append->first!=NULL); |
326 | pq->last->next = append->first; |
327 | append->first->prev = pq->last; |
328 | pq->last = append->last; |
329 | } |
330 | return count; |
331 | } |
332 | |