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911ab6b9 | 1 | /* "Bag-of-pages" garbage collector for the GNU compiler. |
d353bf18 | 2 | Copyright (C) 1999-2015 Free Software Foundation, Inc. |
911ab6b9 | 3 | |
f12b58b3 | 4 | This file is part of GCC. |
911ab6b9 | 5 | |
f12b58b3 | 6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 8 | Software Foundation; either version 3, or (at your option) any later |
f12b58b3 | 9 | version. |
911ab6b9 | 10 | |
f12b58b3 | 11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
911ab6b9 | 15 | |
90856340 | 16 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
911ab6b9 | 19 | |
911ab6b9 | 20 | #include "config.h" |
911ab6b9 | 21 | #include "system.h" |
805e22b2 | 22 | #include "coretypes.h" |
9ef16211 | 23 | #include "backend.h" |
b20a8bb4 | 24 | #include "alias.h" |
911ab6b9 | 25 | #include "tree.h" |
f01a3c5e | 26 | #include "rtl.h" |
f8e15e8a | 27 | #include "tm_p.h" |
0b205f4c | 28 | #include "diagnostic-core.h" |
911ab6b9 | 29 | #include "flags.h" |
ba72912a | 30 | #include "ggc-internal.h" |
74d2af64 | 31 | #include "timevar.h" |
2a3edec5 | 32 | #include "params.h" |
073c1fd5 | 33 | #include "cgraph.h" |
3089b75c | 34 | #include "cfgloop.h" |
740cd0be | 35 | #include "plugin.h" |
f01a3c5e | 36 | |
901dfcc7 | 37 | /* Prefer MAP_ANON(YMOUS) to /dev/zero, since we don't need to keep a |
38 | file open. Prefer either to valloc. */ | |
39 | #ifdef HAVE_MMAP_ANON | |
40 | # undef HAVE_MMAP_DEV_ZERO | |
901dfcc7 | 41 | # define USING_MMAP |
71661611 | 42 | #endif |
911ab6b9 | 43 | |
901dfcc7 | 44 | #ifdef HAVE_MMAP_DEV_ZERO |
901dfcc7 | 45 | # define USING_MMAP |
80d3ceff | 46 | #endif |
47 | ||
80eb2355 | 48 | #ifndef USING_MMAP |
49 | #define USING_MALLOC_PAGE_GROUPS | |
d3b95fd7 | 50 | #endif |
911ab6b9 | 51 | |
f4245e06 | 52 | #if defined(HAVE_MADVISE) && HAVE_DECL_MADVISE && defined(MADV_DONTNEED) \ |
53 | && defined(USING_MMAP) | |
c5db973f | 54 | # define USING_MADVISE |
55 | #endif | |
56 | ||
442e3cb9 | 57 | /* Strategy: |
911ab6b9 | 58 | |
59 | This garbage-collecting allocator allocates objects on one of a set | |
60 | of pages. Each page can allocate objects of a single size only; | |
61 | available sizes are powers of two starting at four bytes. The size | |
62 | of an allocation request is rounded up to the next power of two | |
63 | (`order'), and satisfied from the appropriate page. | |
64 | ||
65 | Each page is recorded in a page-entry, which also maintains an | |
66 | in-use bitmap of object positions on the page. This allows the | |
67 | allocation state of a particular object to be flipped without | |
68 | touching the page itself. | |
69 | ||
70 | Each page-entry also has a context depth, which is used to track | |
71 | pushing and popping of allocation contexts. Only objects allocated | |
3cfec666 | 72 | in the current (highest-numbered) context may be collected. |
911ab6b9 | 73 | |
74 | Page entries are arranged in an array of singly-linked lists. The | |
75 | array is indexed by the allocation size, in bits, of the pages on | |
76 | it; i.e. all pages on a list allocate objects of the same size. | |
77 | Pages are ordered on the list such that all non-full pages precede | |
78 | all full pages, with non-full pages arranged in order of decreasing | |
79 | context depth. | |
80 | ||
81 | Empty pages (of all orders) are kept on a single page cache list, | |
82 | and are considered first when new pages are required; they are | |
83 | deallocated at the start of the next collection if they haven't | |
84 | been recycled by then. */ | |
85 | ||
911ab6b9 | 86 | /* Define GGC_DEBUG_LEVEL to print debugging information. |
87 | 0: No debugging output. | |
88 | 1: GC statistics only. | |
89 | 2: Page-entry allocations/deallocations as well. | |
90 | 3: Object allocations as well. | |
1e625a2e | 91 | 4: Object marks as well. */ |
911ab6b9 | 92 | #define GGC_DEBUG_LEVEL (0) |
93 | \f | |
94 | #ifndef HOST_BITS_PER_PTR | |
95 | #define HOST_BITS_PER_PTR HOST_BITS_PER_LONG | |
96 | #endif | |
97 | ||
911ab6b9 | 98 | \f |
99 | /* A two-level tree is used to look up the page-entry for a given | |
100 | pointer. Two chunks of the pointer's bits are extracted to index | |
101 | the first and second levels of the tree, as follows: | |
102 | ||
103 | HOST_PAGE_SIZE_BITS | |
104 | 32 | | | |
105 | msb +----------------+----+------+------+ lsb | |
106 | | | | | |
107 | PAGE_L1_BITS | | |
108 | | | | |
109 | PAGE_L2_BITS | |
110 | ||
111 | The bottommost HOST_PAGE_SIZE_BITS are ignored, since page-entry | |
112 | pages are aligned on system page boundaries. The next most | |
113 | significant PAGE_L2_BITS and PAGE_L1_BITS are the second and first | |
3cfec666 | 114 | index values in the lookup table, respectively. |
911ab6b9 | 115 | |
71661611 | 116 | For 32-bit architectures and the settings below, there are no |
117 | leftover bits. For architectures with wider pointers, the lookup | |
118 | tree points to a list of pages, which must be scanned to find the | |
119 | correct one. */ | |
911ab6b9 | 120 | |
121 | #define PAGE_L1_BITS (8) | |
122 | #define PAGE_L2_BITS (32 - PAGE_L1_BITS - G.lg_pagesize) | |
337c992b | 123 | #define PAGE_L1_SIZE ((uintptr_t) 1 << PAGE_L1_BITS) |
124 | #define PAGE_L2_SIZE ((uintptr_t) 1 << PAGE_L2_BITS) | |
911ab6b9 | 125 | |
126 | #define LOOKUP_L1(p) \ | |
337c992b | 127 | (((uintptr_t) (p) >> (32 - PAGE_L1_BITS)) & ((1 << PAGE_L1_BITS) - 1)) |
911ab6b9 | 128 | |
129 | #define LOOKUP_L2(p) \ | |
337c992b | 130 | (((uintptr_t) (p) >> G.lg_pagesize) & ((1 << PAGE_L2_BITS) - 1)) |
911ab6b9 | 131 | |
2f6aecaf | 132 | /* The number of objects per allocation page, for objects on a page of |
133 | the indicated ORDER. */ | |
134 | #define OBJECTS_PER_PAGE(ORDER) objects_per_page_table[ORDER] | |
135 | ||
573aba85 | 136 | /* The number of objects in P. */ |
137 | #define OBJECTS_IN_PAGE(P) ((P)->bytes / OBJECT_SIZE ((P)->order)) | |
138 | ||
2f6aecaf | 139 | /* The size of an object on a page of the indicated ORDER. */ |
140 | #define OBJECT_SIZE(ORDER) object_size_table[ORDER] | |
141 | ||
40b9be5e | 142 | /* For speed, we avoid doing a general integer divide to locate the |
143 | offset in the allocation bitmap, by precalculating numbers M, S | |
144 | such that (O * M) >> S == O / Z (modulo 2^32), for any offset O | |
145 | within the page which is evenly divisible by the object size Z. */ | |
146 | #define DIV_MULT(ORDER) inverse_table[ORDER].mult | |
147 | #define DIV_SHIFT(ORDER) inverse_table[ORDER].shift | |
148 | #define OFFSET_TO_BIT(OFFSET, ORDER) \ | |
149 | (((OFFSET) * DIV_MULT (ORDER)) >> DIV_SHIFT (ORDER)) | |
150 | ||
3089b75c | 151 | /* We use this structure to determine the alignment required for |
152 | allocations. For power-of-two sized allocations, that's not a | |
153 | problem, but it does matter for odd-sized allocations. | |
154 | We do not care about alignment for floating-point types. */ | |
155 | ||
156 | struct max_alignment { | |
157 | char c; | |
158 | union { | |
3a4303e7 | 159 | int64_t i; |
3089b75c | 160 | void *p; |
161 | } u; | |
162 | }; | |
163 | ||
164 | /* The biggest alignment required. */ | |
165 | ||
166 | #define MAX_ALIGNMENT (offsetof (struct max_alignment, u)) | |
167 | ||
168 | ||
2f6aecaf | 169 | /* The number of extra orders, not corresponding to power-of-two sized |
170 | objects. */ | |
171 | ||
3585dac7 | 172 | #define NUM_EXTRA_ORDERS ARRAY_SIZE (extra_order_size_table) |
2f6aecaf | 173 | |
7bf41779 | 174 | #define RTL_SIZE(NSLOTS) \ |
bf6b5685 | 175 | (RTX_HDR_SIZE + (NSLOTS) * sizeof (rtunion)) |
7bf41779 | 176 | |
761cbb5d | 177 | #define TREE_EXP_SIZE(OPS) \ |
178 | (sizeof (struct tree_exp) + ((OPS) - 1) * sizeof (tree)) | |
179 | ||
2f6aecaf | 180 | /* The Ith entry is the maximum size of an object to be stored in the |
181 | Ith extra order. Adding a new entry to this array is the *only* | |
182 | thing you need to do to add a new special allocation size. */ | |
183 | ||
184 | static const size_t extra_order_size_table[] = { | |
3089b75c | 185 | /* Extra orders for small non-power-of-two multiples of MAX_ALIGNMENT. |
186 | There are a lot of structures with these sizes and explicitly | |
187 | listing them risks orders being dropped because they changed size. */ | |
188 | MAX_ALIGNMENT * 3, | |
189 | MAX_ALIGNMENT * 5, | |
190 | MAX_ALIGNMENT * 6, | |
191 | MAX_ALIGNMENT * 7, | |
192 | MAX_ALIGNMENT * 9, | |
193 | MAX_ALIGNMENT * 10, | |
194 | MAX_ALIGNMENT * 11, | |
195 | MAX_ALIGNMENT * 12, | |
196 | MAX_ALIGNMENT * 13, | |
197 | MAX_ALIGNMENT * 14, | |
198 | MAX_ALIGNMENT * 15, | |
5ded8c6f | 199 | sizeof (struct tree_decl_non_common), |
200 | sizeof (struct tree_field_decl), | |
201 | sizeof (struct tree_parm_decl), | |
202 | sizeof (struct tree_var_decl), | |
8f2eb9e1 | 203 | sizeof (struct tree_type_non_common), |
1c2a6a66 | 204 | sizeof (struct function), |
205 | sizeof (struct basic_block_def), | |
3089b75c | 206 | sizeof (struct cgraph_node), |
207 | sizeof (struct loop), | |
2f6aecaf | 208 | }; |
209 | ||
210 | /* The total number of orders. */ | |
211 | ||
212 | #define NUM_ORDERS (HOST_BITS_PER_PTR + NUM_EXTRA_ORDERS) | |
213 | ||
573aba85 | 214 | /* Compute the smallest nonnegative number which when added to X gives |
215 | a multiple of F. */ | |
216 | ||
217 | #define ROUND_UP_VALUE(x, f) ((f) - 1 - ((f) - 1 + (x)) % (f)) | |
218 | ||
25a28b44 | 219 | /* Round X to next multiple of the page size */ |
220 | ||
02ce3c0f | 221 | #define PAGE_ALIGN(x) ROUND_UP ((x), G.pagesize) |
25a28b44 | 222 | |
2f6aecaf | 223 | /* The Ith entry is the number of objects on a page or order I. */ |
224 | ||
225 | static unsigned objects_per_page_table[NUM_ORDERS]; | |
226 | ||
227 | /* The Ith entry is the size of an object on a page of order I. */ | |
228 | ||
229 | static size_t object_size_table[NUM_ORDERS]; | |
911ab6b9 | 230 | |
40b9be5e | 231 | /* The Ith entry is a pair of numbers (mult, shift) such that |
232 | ((k * mult) >> shift) mod 2^32 == (k / OBJECT_SIZE(I)) mod 2^32, | |
233 | for all k evenly divisible by OBJECT_SIZE(I). */ | |
234 | ||
235 | static struct | |
236 | { | |
2c06e494 | 237 | size_t mult; |
40b9be5e | 238 | unsigned int shift; |
239 | } | |
240 | inverse_table[NUM_ORDERS]; | |
241 | ||
911ab6b9 | 242 | /* A page_entry records the status of an allocation page. This |
243 | structure is dynamically sized to fit the bitmap in_use_p. */ | |
6dc50383 | 244 | struct page_entry |
911ab6b9 | 245 | { |
246 | /* The next page-entry with objects of the same size, or NULL if | |
247 | this is the last page-entry. */ | |
248 | struct page_entry *next; | |
249 | ||
4a755ae7 | 250 | /* The previous page-entry with objects of the same size, or NULL if |
251 | this is the first page-entry. The PREV pointer exists solely to | |
5aedf60c | 252 | keep the cost of ggc_free manageable. */ |
4a755ae7 | 253 | struct page_entry *prev; |
254 | ||
911ab6b9 | 255 | /* The number of bytes allocated. (This will always be a multiple |
256 | of the host system page size.) */ | |
257 | size_t bytes; | |
258 | ||
259 | /* The address at which the memory is allocated. */ | |
260 | char *page; | |
261 | ||
80eb2355 | 262 | #ifdef USING_MALLOC_PAGE_GROUPS |
263 | /* Back pointer to the page group this page came from. */ | |
264 | struct page_group *group; | |
265 | #endif | |
266 | ||
76e1b933 | 267 | /* This is the index in the by_depth varray where this page table |
268 | can be found. */ | |
269 | unsigned long index_by_depth; | |
911ab6b9 | 270 | |
271 | /* Context depth of this page. */ | |
938cf571 | 272 | unsigned short context_depth; |
911ab6b9 | 273 | |
274 | /* The number of free objects remaining on this page. */ | |
275 | unsigned short num_free_objects; | |
276 | ||
277 | /* A likely candidate for the bit position of a free object for the | |
278 | next allocation from this page. */ | |
279 | unsigned short next_bit_hint; | |
280 | ||
938cf571 | 281 | /* The lg of size of objects allocated from this page. */ |
282 | unsigned char order; | |
283 | ||
c5db973f | 284 | /* Discarded page? */ |
285 | bool discarded; | |
286 | ||
911ab6b9 | 287 | /* A bit vector indicating whether or not objects are in use. The |
288 | Nth bit is one if the Nth object on this page is allocated. This | |
289 | array is dynamically sized. */ | |
290 | unsigned long in_use_p[1]; | |
6dc50383 | 291 | }; |
911ab6b9 | 292 | |
80eb2355 | 293 | #ifdef USING_MALLOC_PAGE_GROUPS |
294 | /* A page_group describes a large allocation from malloc, from which | |
295 | we parcel out aligned pages. */ | |
6dc50383 | 296 | struct page_group |
80eb2355 | 297 | { |
298 | /* A linked list of all extant page groups. */ | |
299 | struct page_group *next; | |
300 | ||
301 | /* The address we received from malloc. */ | |
302 | char *allocation; | |
303 | ||
304 | /* The size of the block. */ | |
305 | size_t alloc_size; | |
306 | ||
307 | /* A bitmask of pages in use. */ | |
308 | unsigned int in_use; | |
6dc50383 | 309 | }; |
80eb2355 | 310 | #endif |
911ab6b9 | 311 | |
312 | #if HOST_BITS_PER_PTR <= 32 | |
313 | ||
314 | /* On 32-bit hosts, we use a two level page table, as pictured above. */ | |
315 | typedef page_entry **page_table[PAGE_L1_SIZE]; | |
316 | ||
317 | #else | |
318 | ||
71661611 | 319 | /* On 64-bit hosts, we use the same two level page tables plus a linked |
320 | list that disambiguates the top 32-bits. There will almost always be | |
911ab6b9 | 321 | exactly one entry in the list. */ |
322 | typedef struct page_table_chain | |
323 | { | |
324 | struct page_table_chain *next; | |
325 | size_t high_bits; | |
326 | page_entry **table[PAGE_L1_SIZE]; | |
327 | } *page_table; | |
328 | ||
329 | #endif | |
330 | ||
92f06184 | 331 | class finalizer |
332 | { | |
333 | public: | |
334 | finalizer (void *addr, void (*f)(void *)) : m_addr (addr), m_function (f) {} | |
335 | ||
336 | void *addr () const { return m_addr; } | |
337 | ||
338 | void call () const { m_function (m_addr); } | |
339 | ||
340 | private: | |
341 | void *m_addr; | |
342 | void (*m_function)(void *); | |
343 | }; | |
344 | ||
345 | class vec_finalizer | |
346 | { | |
347 | public: | |
348 | vec_finalizer (uintptr_t addr, void (*f)(void *), size_t s, size_t n) : | |
349 | m_addr (addr), m_function (f), m_object_size (s), m_n_objects (n) {} | |
350 | ||
351 | void call () const | |
352 | { | |
353 | for (size_t i = 0; i < m_n_objects; i++) | |
354 | m_function (reinterpret_cast<void *> (m_addr + (i * m_object_size))); | |
355 | } | |
356 | ||
357 | void *addr () const { return reinterpret_cast<void *> (m_addr); } | |
358 | ||
359 | private: | |
360 | uintptr_t m_addr; | |
361 | void (*m_function)(void *); | |
362 | size_t m_object_size; | |
363 | size_t m_n_objects; | |
364 | }; | |
365 | ||
3e5823c9 | 366 | #ifdef ENABLE_GC_ALWAYS_COLLECT |
367 | /* List of free objects to be verified as actually free on the | |
368 | next collection. */ | |
369 | struct free_object | |
370 | { | |
371 | void *object; | |
372 | struct free_object *next; | |
373 | }; | |
374 | #endif | |
375 | ||
911ab6b9 | 376 | /* The rest of the global variables. */ |
9908fe4d | 377 | static struct ggc_globals |
911ab6b9 | 378 | { |
379 | /* The Nth element in this array is a page with objects of size 2^N. | |
380 | If there are any pages with free objects, they will be at the | |
381 | head of the list. NULL if there are no page-entries for this | |
382 | object size. */ | |
2f6aecaf | 383 | page_entry *pages[NUM_ORDERS]; |
911ab6b9 | 384 | |
385 | /* The Nth element in this array is the last page with objects of | |
386 | size 2^N. NULL if there are no page-entries for this object | |
387 | size. */ | |
2f6aecaf | 388 | page_entry *page_tails[NUM_ORDERS]; |
911ab6b9 | 389 | |
390 | /* Lookup table for associating allocation pages with object addresses. */ | |
391 | page_table lookup; | |
392 | ||
393 | /* The system's page size. */ | |
394 | size_t pagesize; | |
395 | size_t lg_pagesize; | |
396 | ||
397 | /* Bytes currently allocated. */ | |
398 | size_t allocated; | |
399 | ||
400 | /* Bytes currently allocated at the end of the last collection. */ | |
401 | size_t allocated_last_gc; | |
402 | ||
4e00b6fd | 403 | /* Total amount of memory mapped. */ |
404 | size_t bytes_mapped; | |
405 | ||
598638e2 | 406 | /* Bit N set if any allocations have been done at context depth N. */ |
407 | unsigned long context_depth_allocations; | |
408 | ||
409 | /* Bit N set if any collections have been done at context depth N. */ | |
410 | unsigned long context_depth_collections; | |
411 | ||
911ab6b9 | 412 | /* The current depth in the context stack. */ |
2d15cd89 | 413 | unsigned short context_depth; |
911ab6b9 | 414 | |
415 | /* A file descriptor open to /dev/zero for reading. */ | |
901dfcc7 | 416 | #if defined (HAVE_MMAP_DEV_ZERO) |
911ab6b9 | 417 | int dev_zero_fd; |
418 | #endif | |
419 | ||
420 | /* A cache of free system pages. */ | |
421 | page_entry *free_pages; | |
422 | ||
80eb2355 | 423 | #ifdef USING_MALLOC_PAGE_GROUPS |
424 | page_group *page_groups; | |
425 | #endif | |
426 | ||
911ab6b9 | 427 | /* The file descriptor for debugging output. */ |
428 | FILE *debug_file; | |
76e1b933 | 429 | |
430 | /* Current number of elements in use in depth below. */ | |
431 | unsigned int depth_in_use; | |
432 | ||
433 | /* Maximum number of elements that can be used before resizing. */ | |
434 | unsigned int depth_max; | |
435 | ||
f0b5f617 | 436 | /* Each element of this array is an index in by_depth where the given |
76e1b933 | 437 | depth starts. This structure is indexed by that given depth we |
438 | are interested in. */ | |
439 | unsigned int *depth; | |
440 | ||
441 | /* Current number of elements in use in by_depth below. */ | |
442 | unsigned int by_depth_in_use; | |
443 | ||
444 | /* Maximum number of elements that can be used before resizing. */ | |
445 | unsigned int by_depth_max; | |
446 | ||
447 | /* Each element of this array is a pointer to a page_entry, all | |
448 | page_entries can be found in here by increasing depth. | |
449 | index_by_depth in the page_entry is the index into this data | |
450 | structure where that page_entry can be found. This is used to | |
451 | speed up finding all page_entries at a particular depth. */ | |
452 | page_entry **by_depth; | |
453 | ||
454 | /* Each element is a pointer to the saved in_use_p bits, if any, | |
455 | zero otherwise. We allocate them all together, to enable a | |
456 | better runtime data access pattern. */ | |
457 | unsigned long **save_in_use; | |
c4e03242 | 458 | |
92f06184 | 459 | /* Finalizers for single objects. */ |
460 | vec<finalizer> finalizers; | |
461 | ||
462 | /* Finalizers for vectors of objects. */ | |
463 | vec<vec_finalizer> vec_finalizers; | |
464 | ||
c4e03242 | 465 | #ifdef ENABLE_GC_ALWAYS_COLLECT |
466 | /* List of free objects to be verified as actually free on the | |
467 | next collection. */ | |
3e5823c9 | 468 | struct free_object *free_object_list; |
c4e03242 | 469 | #endif |
470 | ||
b7257530 | 471 | struct |
472 | { | |
ba72912a | 473 | /* Total GC-allocated memory. */ |
b7257530 | 474 | unsigned long long total_allocated; |
ba72912a | 475 | /* Total overhead for GC-allocated memory. */ |
b7257530 | 476 | unsigned long long total_overhead; |
477 | ||
478 | /* Total allocations and overhead for sizes less than 32, 64 and 128. | |
479 | These sizes are interesting because they are typical cache line | |
b4b174c3 | 480 | sizes. */ |
48e1416a | 481 | |
b7257530 | 482 | unsigned long long total_allocated_under32; |
483 | unsigned long long total_overhead_under32; | |
48e1416a | 484 | |
b7257530 | 485 | unsigned long long total_allocated_under64; |
486 | unsigned long long total_overhead_under64; | |
48e1416a | 487 | |
b7257530 | 488 | unsigned long long total_allocated_under128; |
489 | unsigned long long total_overhead_under128; | |
48e1416a | 490 | |
86736f9e | 491 | /* The allocations for each of the allocation orders. */ |
492 | unsigned long long total_allocated_per_order[NUM_ORDERS]; | |
493 | ||
b4b174c3 | 494 | /* The overhead for each of the allocation orders. */ |
b7257530 | 495 | unsigned long long total_overhead_per_order[NUM_ORDERS]; |
496 | } stats; | |
911ab6b9 | 497 | } G; |
498 | ||
8f359205 | 499 | /* True if a gc is currently taking place. */ |
500 | ||
501 | static bool in_gc = false; | |
502 | ||
911ab6b9 | 503 | /* The size in bytes required to maintain a bitmap for the objects |
504 | on a page-entry. */ | |
505 | #define BITMAP_SIZE(Num_objects) \ | |
9af5ce0c | 506 | (CEIL ((Num_objects), HOST_BITS_PER_LONG) * sizeof (long)) |
911ab6b9 | 507 | |
80eb2355 | 508 | /* Allocate pages in chunks of this size, to throttle calls to memory |
509 | allocation routines. The first page is used, the rest go onto the | |
510 | free list. This cannot be larger than HOST_BITS_PER_INT for the | |
28a61eb7 | 511 | in_use bitmask for page_group. Hosts that need a different value |
dac49aa5 | 512 | can override this by defining GGC_QUIRE_SIZE explicitly. */ |
28a61eb7 | 513 | #ifndef GGC_QUIRE_SIZE |
514 | # ifdef USING_MMAP | |
ada13b28 | 515 | # define GGC_QUIRE_SIZE 512 /* 2MB for 4K pages */ |
28a61eb7 | 516 | # else |
517 | # define GGC_QUIRE_SIZE 16 | |
518 | # endif | |
519 | #endif | |
76e1b933 | 520 | |
521 | /* Initial guess as to how many page table entries we might need. */ | |
522 | #define INITIAL_PTE_COUNT 128 | |
911ab6b9 | 523 | \f |
6ec1f4e0 | 524 | static int ggc_allocated_p (const void *); |
525 | static page_entry *lookup_page_table_entry (const void *); | |
526 | static void set_page_table_entry (void *, page_entry *); | |
80eb2355 | 527 | #ifdef USING_MMAP |
4a2f812e | 528 | static char *alloc_anon (char *, size_t, bool check); |
80eb2355 | 529 | #endif |
530 | #ifdef USING_MALLOC_PAGE_GROUPS | |
6ec1f4e0 | 531 | static size_t page_group_index (char *, char *); |
532 | static void set_page_group_in_use (page_group *, char *); | |
533 | static void clear_page_group_in_use (page_group *, char *); | |
80eb2355 | 534 | #endif |
6ec1f4e0 | 535 | static struct page_entry * alloc_page (unsigned); |
536 | static void free_page (struct page_entry *); | |
537 | static void release_pages (void); | |
538 | static void clear_marks (void); | |
539 | static void sweep_pages (void); | |
540 | static void ggc_recalculate_in_use_p (page_entry *); | |
541 | static void compute_inverse (unsigned); | |
542 | static inline void adjust_depth (void); | |
543 | static void move_ptes_to_front (int, int); | |
911ab6b9 | 544 | |
6ec1f4e0 | 545 | void debug_print_page_list (int); |
546 | static void push_depth (unsigned int); | |
547 | static void push_by_depth (page_entry *, unsigned long *); | |
7d60cc60 | 548 | |
76e1b933 | 549 | /* Push an entry onto G.depth. */ |
550 | ||
551 | inline static void | |
6ec1f4e0 | 552 | push_depth (unsigned int i) |
76e1b933 | 553 | { |
554 | if (G.depth_in_use >= G.depth_max) | |
555 | { | |
556 | G.depth_max *= 2; | |
4077bf7a | 557 | G.depth = XRESIZEVEC (unsigned int, G.depth, G.depth_max); |
76e1b933 | 558 | } |
559 | G.depth[G.depth_in_use++] = i; | |
560 | } | |
561 | ||
562 | /* Push an entry onto G.by_depth and G.save_in_use. */ | |
563 | ||
564 | inline static void | |
6ec1f4e0 | 565 | push_by_depth (page_entry *p, unsigned long *s) |
76e1b933 | 566 | { |
567 | if (G.by_depth_in_use >= G.by_depth_max) | |
568 | { | |
569 | G.by_depth_max *= 2; | |
4077bf7a | 570 | G.by_depth = XRESIZEVEC (page_entry *, G.by_depth, G.by_depth_max); |
571 | G.save_in_use = XRESIZEVEC (unsigned long *, G.save_in_use, | |
572 | G.by_depth_max); | |
76e1b933 | 573 | } |
574 | G.by_depth[G.by_depth_in_use] = p; | |
575 | G.save_in_use[G.by_depth_in_use++] = s; | |
576 | } | |
577 | ||
578 | #if (GCC_VERSION < 3001) | |
579 | #define prefetch(X) ((void) X) | |
580 | #else | |
581 | #define prefetch(X) __builtin_prefetch (X) | |
582 | #endif | |
583 | ||
584 | #define save_in_use_p_i(__i) \ | |
585 | (G.save_in_use[__i]) | |
586 | #define save_in_use_p(__p) \ | |
587 | (save_in_use_p_i (__p->index_by_depth)) | |
588 | ||
6ef828f9 | 589 | /* Returns nonzero if P was allocated in GC'able memory. */ |
911ab6b9 | 590 | |
71661611 | 591 | static inline int |
6ec1f4e0 | 592 | ggc_allocated_p (const void *p) |
911ab6b9 | 593 | { |
594 | page_entry ***base; | |
71661611 | 595 | size_t L1, L2; |
911ab6b9 | 596 | |
597 | #if HOST_BITS_PER_PTR <= 32 | |
598 | base = &G.lookup[0]; | |
599 | #else | |
600 | page_table table = G.lookup; | |
337c992b | 601 | uintptr_t high_bits = (uintptr_t) p & ~ (uintptr_t) 0xffffffff; |
71661611 | 602 | while (1) |
603 | { | |
604 | if (table == NULL) | |
605 | return 0; | |
606 | if (table->high_bits == high_bits) | |
607 | break; | |
608 | table = table->next; | |
609 | } | |
911ab6b9 | 610 | base = &table->table[0]; |
611 | #endif | |
612 | ||
4a82352a | 613 | /* Extract the level 1 and 2 indices. */ |
e3691812 | 614 | L1 = LOOKUP_L1 (p); |
615 | L2 = LOOKUP_L2 (p); | |
616 | ||
617 | return base[L1] && base[L1][L2]; | |
618 | } | |
619 | ||
3cfec666 | 620 | /* Traverse the page table and find the entry for a page. |
e3691812 | 621 | Die (probably) if the object wasn't allocated via GC. */ |
622 | ||
623 | static inline page_entry * | |
6ec1f4e0 | 624 | lookup_page_table_entry (const void *p) |
e3691812 | 625 | { |
626 | page_entry ***base; | |
627 | size_t L1, L2; | |
628 | ||
71661611 | 629 | #if HOST_BITS_PER_PTR <= 32 |
630 | base = &G.lookup[0]; | |
631 | #else | |
632 | page_table table = G.lookup; | |
337c992b | 633 | uintptr_t high_bits = (uintptr_t) p & ~ (uintptr_t) 0xffffffff; |
71661611 | 634 | while (table->high_bits != high_bits) |
635 | table = table->next; | |
636 | base = &table->table[0]; | |
637 | #endif | |
e3691812 | 638 | |
4a82352a | 639 | /* Extract the level 1 and 2 indices. */ |
911ab6b9 | 640 | L1 = LOOKUP_L1 (p); |
641 | L2 = LOOKUP_L2 (p); | |
642 | ||
643 | return base[L1][L2]; | |
644 | } | |
645 | ||
911ab6b9 | 646 | /* Set the page table entry for a page. */ |
e3c4633e | 647 | |
911ab6b9 | 648 | static void |
6ec1f4e0 | 649 | set_page_table_entry (void *p, page_entry *entry) |
911ab6b9 | 650 | { |
651 | page_entry ***base; | |
652 | size_t L1, L2; | |
653 | ||
654 | #if HOST_BITS_PER_PTR <= 32 | |
655 | base = &G.lookup[0]; | |
656 | #else | |
657 | page_table table; | |
337c992b | 658 | uintptr_t high_bits = (uintptr_t) p & ~ (uintptr_t) 0xffffffff; |
911ab6b9 | 659 | for (table = G.lookup; table; table = table->next) |
660 | if (table->high_bits == high_bits) | |
661 | goto found; | |
662 | ||
663 | /* Not found -- allocate a new table. */ | |
c768b48b | 664 | table = XCNEW (struct page_table_chain); |
911ab6b9 | 665 | table->next = G.lookup; |
666 | table->high_bits = high_bits; | |
667 | G.lookup = table; | |
668 | found: | |
669 | base = &table->table[0]; | |
670 | #endif | |
671 | ||
4a82352a | 672 | /* Extract the level 1 and 2 indices. */ |
911ab6b9 | 673 | L1 = LOOKUP_L1 (p); |
674 | L2 = LOOKUP_L2 (p); | |
675 | ||
676 | if (base[L1] == NULL) | |
4c36ffe6 | 677 | base[L1] = XCNEWVEC (page_entry *, PAGE_L2_SIZE); |
911ab6b9 | 678 | |
679 | base[L1][L2] = entry; | |
680 | } | |
681 | ||
911ab6b9 | 682 | /* Prints the page-entry for object size ORDER, for debugging. */ |
e3c4633e | 683 | |
4b987fac | 684 | DEBUG_FUNCTION void |
6ec1f4e0 | 685 | debug_print_page_list (int order) |
911ab6b9 | 686 | { |
687 | page_entry *p; | |
6ec1f4e0 | 688 | printf ("Head=%p, Tail=%p:\n", (void *) G.pages[order], |
689 | (void *) G.page_tails[order]); | |
911ab6b9 | 690 | p = G.pages[order]; |
691 | while (p != NULL) | |
692 | { | |
6ec1f4e0 | 693 | printf ("%p(%1d|%3d) -> ", (void *) p, p->context_depth, |
f8cb9479 | 694 | p->num_free_objects); |
911ab6b9 | 695 | p = p->next; |
696 | } | |
697 | printf ("NULL\n"); | |
698 | fflush (stdout); | |
699 | } | |
700 | ||
80eb2355 | 701 | #ifdef USING_MMAP |
911ab6b9 | 702 | /* Allocate SIZE bytes of anonymous memory, preferably near PREF, |
901dfcc7 | 703 | (if non-null). The ifdef structure here is intended to cause a |
704 | compile error unless exactly one of the HAVE_* is defined. */ | |
e3c4633e | 705 | |
911ab6b9 | 706 | static inline char * |
4a2f812e | 707 | alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size, bool check) |
911ab6b9 | 708 | { |
901dfcc7 | 709 | #ifdef HAVE_MMAP_ANON |
4077bf7a | 710 | char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, |
711 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
901dfcc7 | 712 | #endif |
713 | #ifdef HAVE_MMAP_DEV_ZERO | |
4077bf7a | 714 | char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, |
715 | MAP_PRIVATE, G.dev_zero_fd, 0); | |
911ab6b9 | 716 | #endif |
901dfcc7 | 717 | |
718 | if (page == (char *) MAP_FAILED) | |
71661611 | 719 | { |
4a2f812e | 720 | if (!check) |
721 | return NULL; | |
cb8bacb6 | 722 | perror ("virtual memory exhausted"); |
018eba2e | 723 | exit (FATAL_EXIT_CODE); |
71661611 | 724 | } |
911ab6b9 | 725 | |
4e00b6fd | 726 | /* Remember that we allocated this memory. */ |
727 | G.bytes_mapped += size; | |
728 | ||
dd359afe | 729 | /* Pretend we don't have access to the allocated pages. We'll enable |
ba72912a | 730 | access to smaller pieces of the area in ggc_internal_alloc. Discard the |
dd359afe | 731 | handle to avoid handle leak. */ |
a7779e75 | 732 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (page, size)); |
dd359afe | 733 | |
911ab6b9 | 734 | return page; |
735 | } | |
80eb2355 | 736 | #endif |
737 | #ifdef USING_MALLOC_PAGE_GROUPS | |
738 | /* Compute the index for this page into the page group. */ | |
739 | ||
740 | static inline size_t | |
6ec1f4e0 | 741 | page_group_index (char *allocation, char *page) |
80eb2355 | 742 | { |
dfe09cce | 743 | return (size_t) (page - allocation) >> G.lg_pagesize; |
80eb2355 | 744 | } |
745 | ||
746 | /* Set and clear the in_use bit for this page in the page group. */ | |
747 | ||
748 | static inline void | |
6ec1f4e0 | 749 | set_page_group_in_use (page_group *group, char *page) |
80eb2355 | 750 | { |
751 | group->in_use |= 1 << page_group_index (group->allocation, page); | |
752 | } | |
753 | ||
754 | static inline void | |
6ec1f4e0 | 755 | clear_page_group_in_use (page_group *group, char *page) |
80eb2355 | 756 | { |
757 | group->in_use &= ~(1 << page_group_index (group->allocation, page)); | |
758 | } | |
759 | #endif | |
911ab6b9 | 760 | |
761 | /* Allocate a new page for allocating objects of size 2^ORDER, | |
762 | and return an entry for it. The entry is not added to the | |
763 | appropriate page_table list. */ | |
e3c4633e | 764 | |
911ab6b9 | 765 | static inline struct page_entry * |
6ec1f4e0 | 766 | alloc_page (unsigned order) |
911ab6b9 | 767 | { |
768 | struct page_entry *entry, *p, **pp; | |
769 | char *page; | |
770 | size_t num_objects; | |
771 | size_t bitmap_size; | |
772 | size_t page_entry_size; | |
773 | size_t entry_size; | |
80eb2355 | 774 | #ifdef USING_MALLOC_PAGE_GROUPS |
775 | page_group *group; | |
776 | #endif | |
911ab6b9 | 777 | |
778 | num_objects = OBJECTS_PER_PAGE (order); | |
779 | bitmap_size = BITMAP_SIZE (num_objects + 1); | |
780 | page_entry_size = sizeof (page_entry) - sizeof (long) + bitmap_size; | |
2f6aecaf | 781 | entry_size = num_objects * OBJECT_SIZE (order); |
9acc7238 | 782 | if (entry_size < G.pagesize) |
783 | entry_size = G.pagesize; | |
25a28b44 | 784 | entry_size = PAGE_ALIGN (entry_size); |
911ab6b9 | 785 | |
786 | entry = NULL; | |
787 | page = NULL; | |
788 | ||
789 | /* Check the list of free pages for one we can use. */ | |
018eba2e | 790 | for (pp = &G.free_pages, p = *pp; p; pp = &p->next, p = *pp) |
911ab6b9 | 791 | if (p->bytes == entry_size) |
792 | break; | |
793 | ||
794 | if (p != NULL) | |
795 | { | |
c5db973f | 796 | if (p->discarded) |
797 | G.bytes_mapped += p->bytes; | |
798 | p->discarded = false; | |
799 | ||
aa40f561 | 800 | /* Recycle the allocated memory from this page ... */ |
911ab6b9 | 801 | *pp = p->next; |
802 | page = p->page; | |
018eba2e | 803 | |
80eb2355 | 804 | #ifdef USING_MALLOC_PAGE_GROUPS |
805 | group = p->group; | |
806 | #endif | |
018eba2e | 807 | |
911ab6b9 | 808 | /* ... and, if possible, the page entry itself. */ |
809 | if (p->order == order) | |
810 | { | |
811 | entry = p; | |
812 | memset (entry, 0, page_entry_size); | |
813 | } | |
814 | else | |
815 | free (p); | |
816 | } | |
901dfcc7 | 817 | #ifdef USING_MMAP |
9a2e8b0a | 818 | else if (entry_size == G.pagesize) |
911ab6b9 | 819 | { |
9a2e8b0a | 820 | /* We want just one page. Allocate a bunch of them and put the |
821 | extras on the freelist. (Can only do this optimization with | |
822 | mmap for backing store.) */ | |
823 | struct page_entry *e, *f = G.free_pages; | |
4a2f812e | 824 | int i, entries = GGC_QUIRE_SIZE; |
9a2e8b0a | 825 | |
4a2f812e | 826 | page = alloc_anon (NULL, G.pagesize * GGC_QUIRE_SIZE, false); |
827 | if (page == NULL) | |
828 | { | |
9af5ce0c | 829 | page = alloc_anon (NULL, G.pagesize, true); |
4a2f812e | 830 | entries = 1; |
831 | } | |
018eba2e | 832 | |
9a2e8b0a | 833 | /* This loop counts down so that the chain will be in ascending |
834 | memory order. */ | |
4a2f812e | 835 | for (i = entries - 1; i >= 1; i--) |
9a2e8b0a | 836 | { |
4077bf7a | 837 | e = XCNEWVAR (struct page_entry, page_entry_size); |
9acc7238 | 838 | e->order = order; |
839 | e->bytes = G.pagesize; | |
840 | e->page = page + (i << G.lg_pagesize); | |
9a2e8b0a | 841 | e->next = f; |
842 | f = e; | |
843 | } | |
018eba2e | 844 | |
9a2e8b0a | 845 | G.free_pages = f; |
911ab6b9 | 846 | } |
9a2e8b0a | 847 | else |
4a2f812e | 848 | page = alloc_anon (NULL, entry_size, true); |
80eb2355 | 849 | #endif |
850 | #ifdef USING_MALLOC_PAGE_GROUPS | |
851 | else | |
852 | { | |
853 | /* Allocate a large block of memory and serve out the aligned | |
854 | pages therein. This results in much less memory wastage | |
855 | than the traditional implementation of valloc. */ | |
856 | ||
857 | char *allocation, *a, *enda; | |
858 | size_t alloc_size, head_slop, tail_slop; | |
859 | int multiple_pages = (entry_size == G.pagesize); | |
860 | ||
861 | if (multiple_pages) | |
862 | alloc_size = GGC_QUIRE_SIZE * G.pagesize; | |
863 | else | |
864 | alloc_size = entry_size + G.pagesize - 1; | |
781dec7f | 865 | allocation = XNEWVEC (char, alloc_size); |
80eb2355 | 866 | |
337c992b | 867 | page = (char *) (((uintptr_t) allocation + G.pagesize - 1) & -G.pagesize); |
80eb2355 | 868 | head_slop = page - allocation; |
869 | if (multiple_pages) | |
870 | tail_slop = ((size_t) allocation + alloc_size) & (G.pagesize - 1); | |
871 | else | |
872 | tail_slop = alloc_size - entry_size - head_slop; | |
873 | enda = allocation + alloc_size - tail_slop; | |
874 | ||
875 | /* We allocated N pages, which are likely not aligned, leaving | |
876 | us with N-1 usable pages. We plan to place the page_group | |
877 | structure somewhere in the slop. */ | |
878 | if (head_slop >= sizeof (page_group)) | |
879 | group = (page_group *)page - 1; | |
880 | else | |
881 | { | |
882 | /* We magically got an aligned allocation. Too bad, we have | |
883 | to waste a page anyway. */ | |
884 | if (tail_slop == 0) | |
885 | { | |
886 | enda -= G.pagesize; | |
887 | tail_slop += G.pagesize; | |
888 | } | |
0d59b19d | 889 | gcc_assert (tail_slop >= sizeof (page_group)); |
80eb2355 | 890 | group = (page_group *)enda; |
891 | tail_slop -= sizeof (page_group); | |
892 | } | |
893 | ||
894 | /* Remember that we allocated this memory. */ | |
895 | group->next = G.page_groups; | |
896 | group->allocation = allocation; | |
897 | group->alloc_size = alloc_size; | |
898 | group->in_use = 0; | |
899 | G.page_groups = group; | |
900 | G.bytes_mapped += alloc_size; | |
901 | ||
902 | /* If we allocated multiple pages, put the rest on the free list. */ | |
903 | if (multiple_pages) | |
904 | { | |
905 | struct page_entry *e, *f = G.free_pages; | |
906 | for (a = enda - G.pagesize; a != page; a -= G.pagesize) | |
907 | { | |
781dec7f | 908 | e = XCNEWVAR (struct page_entry, page_entry_size); |
80eb2355 | 909 | e->order = order; |
910 | e->bytes = G.pagesize; | |
911 | e->page = a; | |
912 | e->group = group; | |
913 | e->next = f; | |
914 | f = e; | |
915 | } | |
916 | G.free_pages = f; | |
917 | } | |
918 | } | |
919 | #endif | |
911ab6b9 | 920 | |
921 | if (entry == NULL) | |
4077bf7a | 922 | entry = XCNEWVAR (struct page_entry, page_entry_size); |
911ab6b9 | 923 | |
924 | entry->bytes = entry_size; | |
925 | entry->page = page; | |
926 | entry->context_depth = G.context_depth; | |
927 | entry->order = order; | |
928 | entry->num_free_objects = num_objects; | |
929 | entry->next_bit_hint = 1; | |
930 | ||
598638e2 | 931 | G.context_depth_allocations |= (unsigned long)1 << G.context_depth; |
932 | ||
80eb2355 | 933 | #ifdef USING_MALLOC_PAGE_GROUPS |
934 | entry->group = group; | |
935 | set_page_group_in_use (group, page); | |
936 | #endif | |
937 | ||
911ab6b9 | 938 | /* Set the one-past-the-end in-use bit. This acts as a sentry as we |
939 | increment the hint. */ | |
940 | entry->in_use_p[num_objects / HOST_BITS_PER_LONG] | |
941 | = (unsigned long) 1 << (num_objects % HOST_BITS_PER_LONG); | |
942 | ||
943 | set_page_table_entry (page, entry); | |
944 | ||
945 | if (GGC_DEBUG_LEVEL >= 2) | |
3cfec666 | 946 | fprintf (G.debug_file, |
29e7390a | 947 | "Allocating page at %p, object size=%lu, data %p-%p\n", |
6ec1f4e0 | 948 | (void *) entry, (unsigned long) OBJECT_SIZE (order), page, |
018eba2e | 949 | page + entry_size - 1); |
911ab6b9 | 950 | |
951 | return entry; | |
952 | } | |
953 | ||
76e1b933 | 954 | /* Adjust the size of G.depth so that no index greater than the one |
955 | used by the top of the G.by_depth is used. */ | |
956 | ||
957 | static inline void | |
6ec1f4e0 | 958 | adjust_depth (void) |
76e1b933 | 959 | { |
960 | page_entry *top; | |
961 | ||
962 | if (G.by_depth_in_use) | |
963 | { | |
964 | top = G.by_depth[G.by_depth_in_use-1]; | |
965 | ||
d01481af | 966 | /* Peel back indices in depth that index into by_depth, so that |
967 | as new elements are added to by_depth, we note the indices | |
76e1b933 | 968 | of those elements, if they are for new context depths. */ |
969 | while (G.depth_in_use > (size_t)top->context_depth+1) | |
970 | --G.depth_in_use; | |
971 | } | |
972 | } | |
973 | ||
e3c4633e | 974 | /* For a page that is no longer needed, put it on the free page list. */ |
911ab6b9 | 975 | |
c4e03242 | 976 | static void |
6ec1f4e0 | 977 | free_page (page_entry *entry) |
911ab6b9 | 978 | { |
979 | if (GGC_DEBUG_LEVEL >= 2) | |
3cfec666 | 980 | fprintf (G.debug_file, |
6ec1f4e0 | 981 | "Deallocating page at %p, data %p-%p\n", (void *) entry, |
911ab6b9 | 982 | entry->page, entry->page + entry->bytes - 1); |
983 | ||
dd359afe | 984 | /* Mark the page as inaccessible. Discard the handle to avoid handle |
985 | leak. */ | |
a7779e75 | 986 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (entry->page, entry->bytes)); |
dd359afe | 987 | |
911ab6b9 | 988 | set_page_table_entry (entry->page, NULL); |
989 | ||
80eb2355 | 990 | #ifdef USING_MALLOC_PAGE_GROUPS |
991 | clear_page_group_in_use (entry->group, entry->page); | |
992 | #endif | |
993 | ||
76e1b933 | 994 | if (G.by_depth_in_use > 1) |
995 | { | |
996 | page_entry *top = G.by_depth[G.by_depth_in_use-1]; | |
0d59b19d | 997 | int i = entry->index_by_depth; |
998 | ||
999 | /* We cannot free a page from a context deeper than the current | |
1000 | one. */ | |
1001 | gcc_assert (entry->context_depth == top->context_depth); | |
48e1416a | 1002 | |
0d59b19d | 1003 | /* Put top element into freed slot. */ |
1004 | G.by_depth[i] = top; | |
1005 | G.save_in_use[i] = G.save_in_use[G.by_depth_in_use-1]; | |
1006 | top->index_by_depth = i; | |
76e1b933 | 1007 | } |
1008 | --G.by_depth_in_use; | |
1009 | ||
1010 | adjust_depth (); | |
1011 | ||
911ab6b9 | 1012 | entry->next = G.free_pages; |
1013 | G.free_pages = entry; | |
1014 | } | |
1015 | ||
e3c4633e | 1016 | /* Release the free page cache to the system. */ |
911ab6b9 | 1017 | |
c10b9b1c | 1018 | static void |
6ec1f4e0 | 1019 | release_pages (void) |
911ab6b9 | 1020 | { |
c5db973f | 1021 | #ifdef USING_MADVISE |
1022 | page_entry *p, *start_p; | |
1023 | char *start; | |
1024 | size_t len; | |
e8b7c612 | 1025 | size_t mapped_len; |
1026 | page_entry *next, *prev, *newprev; | |
1027 | size_t free_unit = (GGC_QUIRE_SIZE/2) * G.pagesize; | |
1028 | ||
1029 | /* First free larger continuous areas to the OS. | |
1030 | This allows other allocators to grab these areas if needed. | |
1031 | This is only done on larger chunks to avoid fragmentation. | |
1032 | This does not always work because the free_pages list is only | |
1033 | approximately sorted. */ | |
1034 | ||
1035 | p = G.free_pages; | |
1036 | prev = NULL; | |
1037 | while (p) | |
1038 | { | |
1039 | start = p->page; | |
1040 | start_p = p; | |
1041 | len = 0; | |
1042 | mapped_len = 0; | |
1043 | newprev = prev; | |
1044 | while (p && p->page == start + len) | |
1045 | { | |
1046 | len += p->bytes; | |
1047 | if (!p->discarded) | |
1048 | mapped_len += p->bytes; | |
1049 | newprev = p; | |
1050 | p = p->next; | |
1051 | } | |
1052 | if (len >= free_unit) | |
1053 | { | |
1054 | while (start_p != p) | |
1055 | { | |
1056 | next = start_p->next; | |
1057 | free (start_p); | |
1058 | start_p = next; | |
1059 | } | |
1060 | munmap (start, len); | |
1061 | if (prev) | |
1062 | prev->next = p; | |
1063 | else | |
1064 | G.free_pages = p; | |
1065 | G.bytes_mapped -= mapped_len; | |
1066 | continue; | |
1067 | } | |
1068 | prev = newprev; | |
1069 | } | |
1070 | ||
1071 | /* Now give back the fragmented pages to the OS, but keep the address | |
1072 | space to reuse it next time. */ | |
c5db973f | 1073 | |
1074 | for (p = G.free_pages; p; ) | |
1075 | { | |
1076 | if (p->discarded) | |
1077 | { | |
1078 | p = p->next; | |
1079 | continue; | |
1080 | } | |
1081 | start = p->page; | |
1082 | len = p->bytes; | |
1083 | start_p = p; | |
1084 | p = p->next; | |
1085 | while (p && p->page == start + len) | |
1086 | { | |
1087 | len += p->bytes; | |
1088 | p = p->next; | |
1089 | } | |
1090 | /* Give the page back to the kernel, but don't free the mapping. | |
1091 | This avoids fragmentation in the virtual memory map of the | |
1092 | process. Next time we can reuse it by just touching it. */ | |
1093 | madvise (start, len, MADV_DONTNEED); | |
1094 | /* Don't count those pages as mapped to not touch the garbage collector | |
1095 | unnecessarily. */ | |
1096 | G.bytes_mapped -= len; | |
1097 | while (start_p != p) | |
1098 | { | |
1099 | start_p->discarded = true; | |
1100 | start_p = start_p->next; | |
1101 | } | |
1102 | } | |
1103 | #endif | |
1104 | #if defined(USING_MMAP) && !defined(USING_MADVISE) | |
80eb2355 | 1105 | page_entry *p, *next; |
911ab6b9 | 1106 | char *start; |
1107 | size_t len; | |
1108 | ||
9a2e8b0a | 1109 | /* Gather up adjacent pages so they are unmapped together. */ |
911ab6b9 | 1110 | p = G.free_pages; |
911ab6b9 | 1111 | |
1112 | while (p) | |
1113 | { | |
9a2e8b0a | 1114 | start = p->page; |
911ab6b9 | 1115 | next = p->next; |
9a2e8b0a | 1116 | len = p->bytes; |
911ab6b9 | 1117 | free (p); |
1118 | p = next; | |
911ab6b9 | 1119 | |
9a2e8b0a | 1120 | while (p && p->page == start + len) |
1121 | { | |
1122 | next = p->next; | |
1123 | len += p->bytes; | |
1124 | free (p); | |
1125 | p = next; | |
1126 | } | |
1127 | ||
1128 | munmap (start, len); | |
1129 | G.bytes_mapped -= len; | |
1130 | } | |
71661611 | 1131 | |
911ab6b9 | 1132 | G.free_pages = NULL; |
80eb2355 | 1133 | #endif |
1134 | #ifdef USING_MALLOC_PAGE_GROUPS | |
1135 | page_entry **pp, *p; | |
1136 | page_group **gp, *g; | |
1137 | ||
1138 | /* Remove all pages from free page groups from the list. */ | |
1139 | pp = &G.free_pages; | |
1140 | while ((p = *pp) != NULL) | |
1141 | if (p->group->in_use == 0) | |
1142 | { | |
1143 | *pp = p->next; | |
1144 | free (p); | |
1145 | } | |
1146 | else | |
1147 | pp = &p->next; | |
1148 | ||
1149 | /* Remove all free page groups, and release the storage. */ | |
1150 | gp = &G.page_groups; | |
1151 | while ((g = *gp) != NULL) | |
1152 | if (g->in_use == 0) | |
1153 | { | |
1154 | *gp = g->next; | |
3cfec666 | 1155 | G.bytes_mapped -= g->alloc_size; |
80eb2355 | 1156 | free (g->allocation); |
1157 | } | |
1158 | else | |
1159 | gp = &g->next; | |
1160 | #endif | |
911ab6b9 | 1161 | } |
1162 | ||
911ab6b9 | 1163 | /* This table provides a fast way to determine ceil(log_2(size)) for |
f806fb68 | 1164 | allocation requests. The minimum allocation size is eight bytes. */ |
f68513d3 | 1165 | #define NUM_SIZE_LOOKUP 512 |
1166 | static unsigned char size_lookup[NUM_SIZE_LOOKUP] = | |
f806fb68 | 1167 | { |
3cfec666 | 1168 | 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, |
1169 | 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, | |
1170 | 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
1171 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
1172 | 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
1173 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
1174 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
911ab6b9 | 1175 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, |
911ab6b9 | 1176 | 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, |
1177 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1178 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1179 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1180 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1181 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1182 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1183 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1c2a6a66 | 1184 | 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, |
1185 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1186 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1187 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1188 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1189 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1190 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1191 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1192 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1193 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1194 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1195 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1196 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1197 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1198 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
8c14f57e | 1199 | 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 |
911ab6b9 | 1200 | }; |
1201 | ||
1ae3520e | 1202 | /* For a given size of memory requested for allocation, return the |
1203 | actual size that is going to be allocated, as well as the size | |
1204 | order. */ | |
1205 | ||
1206 | static void | |
1207 | ggc_round_alloc_size_1 (size_t requested_size, | |
1208 | size_t *size_order, | |
1209 | size_t *alloced_size) | |
1210 | { | |
1211 | size_t order, object_size; | |
1212 | ||
1213 | if (requested_size < NUM_SIZE_LOOKUP) | |
1214 | { | |
1215 | order = size_lookup[requested_size]; | |
1216 | object_size = OBJECT_SIZE (order); | |
1217 | } | |
1218 | else | |
1219 | { | |
1220 | order = 10; | |
1221 | while (requested_size > (object_size = OBJECT_SIZE (order))) | |
1222 | order++; | |
1223 | } | |
1224 | ||
1225 | if (size_order) | |
1226 | *size_order = order; | |
1227 | if (alloced_size) | |
1228 | *alloced_size = object_size; | |
1229 | } | |
1230 | ||
1231 | /* For a given size of memory requested for allocation, return the | |
1232 | actual size that is going to be allocated. */ | |
1233 | ||
1234 | size_t | |
1235 | ggc_round_alloc_size (size_t requested_size) | |
1236 | { | |
1237 | size_t size = 0; | |
1238 | ||
1239 | ggc_round_alloc_size_1 (requested_size, NULL, &size); | |
1240 | return size; | |
1241 | } | |
1242 | ||
908b11c1 | 1243 | /* Allocate a chunk of memory of SIZE bytes. Its contents are undefined. */ |
e3c4633e | 1244 | |
71661611 | 1245 | void * |
92f06184 | 1246 | ggc_internal_alloc (size_t size, void (*f)(void *), size_t s, size_t n |
1247 | MEM_STAT_DECL) | |
911ab6b9 | 1248 | { |
c4e03242 | 1249 | size_t order, word, bit, object_offset, object_size; |
911ab6b9 | 1250 | struct page_entry *entry; |
1251 | void *result; | |
1252 | ||
1ae3520e | 1253 | ggc_round_alloc_size_1 (size, &order, &object_size); |
911ab6b9 | 1254 | |
1255 | /* If there are non-full pages for this size allocation, they are at | |
1256 | the head of the list. */ | |
1257 | entry = G.pages[order]; | |
1258 | ||
1259 | /* If there is no page for this object size, or all pages in this | |
1260 | context are full, allocate a new page. */ | |
c10b9b1c | 1261 | if (entry == NULL || entry->num_free_objects == 0) |
911ab6b9 | 1262 | { |
1263 | struct page_entry *new_entry; | |
1264 | new_entry = alloc_page (order); | |
3cfec666 | 1265 | |
76e1b933 | 1266 | new_entry->index_by_depth = G.by_depth_in_use; |
1267 | push_by_depth (new_entry, 0); | |
1268 | ||
1269 | /* We can skip context depths, if we do, make sure we go all the | |
1270 | way to the new depth. */ | |
1271 | while (new_entry->context_depth >= G.depth_in_use) | |
1272 | push_depth (G.by_depth_in_use-1); | |
1273 | ||
4a755ae7 | 1274 | /* If this is the only entry, it's also the tail. If it is not |
1275 | the only entry, then we must update the PREV pointer of the | |
1276 | ENTRY (G.pages[order]) to point to our new page entry. */ | |
911ab6b9 | 1277 | if (entry == NULL) |
1278 | G.page_tails[order] = new_entry; | |
4a755ae7 | 1279 | else |
1280 | entry->prev = new_entry; | |
3cfec666 | 1281 | |
4a755ae7 | 1282 | /* Put new pages at the head of the page list. By definition the |
1283 | entry at the head of the list always has a NULL pointer. */ | |
911ab6b9 | 1284 | new_entry->next = entry; |
4a755ae7 | 1285 | new_entry->prev = NULL; |
911ab6b9 | 1286 | entry = new_entry; |
1287 | G.pages[order] = new_entry; | |
1288 | ||
1289 | /* For a new page, we know the word and bit positions (in the | |
1290 | in_use bitmap) of the first available object -- they're zero. */ | |
1291 | new_entry->next_bit_hint = 1; | |
1292 | word = 0; | |
1293 | bit = 0; | |
1294 | object_offset = 0; | |
1295 | } | |
1296 | else | |
1297 | { | |
1298 | /* First try to use the hint left from the previous allocation | |
1299 | to locate a clear bit in the in-use bitmap. We've made sure | |
1300 | that the one-past-the-end bit is always set, so if the hint | |
1301 | has run over, this test will fail. */ | |
1302 | unsigned hint = entry->next_bit_hint; | |
1303 | word = hint / HOST_BITS_PER_LONG; | |
1304 | bit = hint % HOST_BITS_PER_LONG; | |
3cfec666 | 1305 | |
911ab6b9 | 1306 | /* If the hint didn't work, scan the bitmap from the beginning. */ |
1307 | if ((entry->in_use_p[word] >> bit) & 1) | |
1308 | { | |
1309 | word = bit = 0; | |
1310 | while (~entry->in_use_p[word] == 0) | |
1311 | ++word; | |
bff49002 | 1312 | |
1313 | #if GCC_VERSION >= 3004 | |
1314 | bit = __builtin_ctzl (~entry->in_use_p[word]); | |
1315 | #else | |
911ab6b9 | 1316 | while ((entry->in_use_p[word] >> bit) & 1) |
1317 | ++bit; | |
bff49002 | 1318 | #endif |
1319 | ||
911ab6b9 | 1320 | hint = word * HOST_BITS_PER_LONG + bit; |
1321 | } | |
1322 | ||
1323 | /* Next time, try the next bit. */ | |
1324 | entry->next_bit_hint = hint + 1; | |
1325 | ||
c4e03242 | 1326 | object_offset = hint * object_size; |
911ab6b9 | 1327 | } |
1328 | ||
1329 | /* Set the in-use bit. */ | |
1330 | entry->in_use_p[word] |= ((unsigned long) 1 << bit); | |
1331 | ||
1332 | /* Keep a running total of the number of free objects. If this page | |
1333 | fills up, we may have to move it to the end of the list if the | |
1334 | next page isn't full. If the next page is full, all subsequent | |
1335 | pages are full, so there's no need to move it. */ | |
1336 | if (--entry->num_free_objects == 0 | |
1337 | && entry->next != NULL | |
1338 | && entry->next->num_free_objects > 0) | |
1339 | { | |
4a755ae7 | 1340 | /* We have a new head for the list. */ |
911ab6b9 | 1341 | G.pages[order] = entry->next; |
4a755ae7 | 1342 | |
1343 | /* We are moving ENTRY to the end of the page table list. | |
1344 | The new page at the head of the list will have NULL in | |
1345 | its PREV field and ENTRY will have NULL in its NEXT field. */ | |
1346 | entry->next->prev = NULL; | |
911ab6b9 | 1347 | entry->next = NULL; |
4a755ae7 | 1348 | |
1349 | /* Append ENTRY to the tail of the list. */ | |
1350 | entry->prev = G.page_tails[order]; | |
911ab6b9 | 1351 | G.page_tails[order]->next = entry; |
1352 | G.page_tails[order] = entry; | |
1353 | } | |
1354 | ||
1355 | /* Calculate the object's address. */ | |
1356 | result = entry->page + object_offset; | |
ecd52ea9 | 1357 | if (GATHER_STATISTICS) |
1358 | ggc_record_overhead (OBJECT_SIZE (order), OBJECT_SIZE (order) - size, | |
1359 | result FINAL_PASS_MEM_STAT); | |
911ab6b9 | 1360 | |
2a3edec5 | 1361 | #ifdef ENABLE_GC_CHECKING |
dd359afe | 1362 | /* Keep poisoning-by-writing-0xaf the object, in an attempt to keep the |
1363 | exact same semantics in presence of memory bugs, regardless of | |
1364 | ENABLE_VALGRIND_CHECKING. We override this request below. Drop the | |
1365 | handle to avoid handle leak. */ | |
a7779e75 | 1366 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, object_size)); |
dd359afe | 1367 | |
791ceafe | 1368 | /* `Poison' the entire allocated object, including any padding at |
1369 | the end. */ | |
c4e03242 | 1370 | memset (result, 0xaf, object_size); |
dd359afe | 1371 | |
1372 | /* Make the bytes after the end of the object unaccessible. Discard the | |
1373 | handle to avoid handle leak. */ | |
a7779e75 | 1374 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *) result + size, |
1375 | object_size - size)); | |
911ab6b9 | 1376 | #endif |
e3c4633e | 1377 | |
dd359afe | 1378 | /* Tell Valgrind that the memory is there, but its content isn't |
1379 | defined. The bytes at the end of the object are still marked | |
1380 | unaccessible. */ | |
a7779e75 | 1381 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, size)); |
dd359afe | 1382 | |
911ab6b9 | 1383 | /* Keep track of how many bytes are being allocated. This |
1384 | information is used in deciding when to collect. */ | |
c4e03242 | 1385 | G.allocated += object_size; |
911ab6b9 | 1386 | |
8d453ddb | 1387 | /* For timevar statistics. */ |
1388 | timevar_ggc_mem_total += object_size; | |
1389 | ||
92f06184 | 1390 | if (f && n == 1) |
1391 | G.finalizers.safe_push (finalizer (result, f)); | |
1392 | else if (f) | |
1393 | G.vec_finalizers.safe_push | |
1394 | (vec_finalizer (reinterpret_cast<uintptr_t> (result), f, s, n)); | |
1395 | ||
ecd52ea9 | 1396 | if (GATHER_STATISTICS) |
1397 | { | |
1398 | size_t overhead = object_size - size; | |
b7257530 | 1399 | |
ecd52ea9 | 1400 | G.stats.total_overhead += overhead; |
1401 | G.stats.total_allocated += object_size; | |
1402 | G.stats.total_overhead_per_order[order] += overhead; | |
1403 | G.stats.total_allocated_per_order[order] += object_size; | |
b7257530 | 1404 | |
ecd52ea9 | 1405 | if (size <= 32) |
1406 | { | |
1407 | G.stats.total_overhead_under32 += overhead; | |
1408 | G.stats.total_allocated_under32 += object_size; | |
1409 | } | |
1410 | if (size <= 64) | |
1411 | { | |
1412 | G.stats.total_overhead_under64 += overhead; | |
1413 | G.stats.total_allocated_under64 += object_size; | |
1414 | } | |
1415 | if (size <= 128) | |
1416 | { | |
1417 | G.stats.total_overhead_under128 += overhead; | |
1418 | G.stats.total_allocated_under128 += object_size; | |
1419 | } | |
1420 | } | |
c4e03242 | 1421 | |
911ab6b9 | 1422 | if (GGC_DEBUG_LEVEL >= 3) |
3cfec666 | 1423 | fprintf (G.debug_file, |
29e7390a | 1424 | "Allocating object, requested size=%lu, actual=%lu at %p on %p\n", |
c4e03242 | 1425 | (unsigned long) size, (unsigned long) object_size, result, |
6ec1f4e0 | 1426 | (void *) entry); |
911ab6b9 | 1427 | |
1428 | return result; | |
1429 | } | |
1430 | ||
dfecde36 | 1431 | /* Mark function for strings. */ |
1432 | ||
1433 | void | |
1434 | gt_ggc_m_S (const void *p) | |
1435 | { | |
1436 | page_entry *entry; | |
1437 | unsigned bit, word; | |
1438 | unsigned long mask; | |
1439 | unsigned long offset; | |
1440 | ||
1441 | if (!p || !ggc_allocated_p (p)) | |
1442 | return; | |
1443 | ||
1444 | /* Look up the page on which the object is alloced. . */ | |
1445 | entry = lookup_page_table_entry (p); | |
1446 | gcc_assert (entry); | |
1447 | ||
1448 | /* Calculate the index of the object on the page; this is its bit | |
1449 | position in the in_use_p bitmap. Note that because a char* might | |
1450 | point to the middle of an object, we need special code here to | |
1451 | make sure P points to the start of an object. */ | |
1452 | offset = ((const char *) p - entry->page) % object_size_table[entry->order]; | |
1453 | if (offset) | |
1454 | { | |
1455 | /* Here we've seen a char* which does not point to the beginning | |
1456 | of an allocated object. We assume it points to the middle of | |
1457 | a STRING_CST. */ | |
1458 | gcc_assert (offset == offsetof (struct tree_string, str)); | |
1459 | p = ((const char *) p) - offset; | |
4077bf7a | 1460 | gt_ggc_mx_lang_tree_node (CONST_CAST (void *, p)); |
dfecde36 | 1461 | return; |
1462 | } | |
1463 | ||
1464 | bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order); | |
1465 | word = bit / HOST_BITS_PER_LONG; | |
1466 | mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG); | |
1467 | ||
1468 | /* If the bit was previously set, skip it. */ | |
1469 | if (entry->in_use_p[word] & mask) | |
1470 | return; | |
1471 | ||
1472 | /* Otherwise set it, and decrement the free object count. */ | |
1473 | entry->in_use_p[word] |= mask; | |
1474 | entry->num_free_objects -= 1; | |
1475 | ||
1476 | if (GGC_DEBUG_LEVEL >= 4) | |
1477 | fprintf (G.debug_file, "Marking %p\n", p); | |
1478 | ||
1479 | return; | |
1480 | } | |
1481 | ||
2b15d2ba | 1482 | |
1483 | /* User-callable entry points for marking string X. */ | |
1484 | ||
1485 | void | |
1486 | gt_ggc_mx (const char *& x) | |
1487 | { | |
1488 | gt_ggc_m_S (x); | |
1489 | } | |
1490 | ||
1491 | void | |
1492 | gt_ggc_mx (unsigned char *& x) | |
1493 | { | |
1494 | gt_ggc_m_S (x); | |
1495 | } | |
1496 | ||
1497 | void | |
1498 | gt_ggc_mx (unsigned char& x ATTRIBUTE_UNUSED) | |
1499 | { | |
1500 | } | |
1501 | ||
e3c4633e | 1502 | /* If P is not marked, marks it and return false. Otherwise return true. |
911ab6b9 | 1503 | P must have been allocated by the GC allocator; it mustn't point to |
1504 | static objects, stack variables, or memory allocated with malloc. */ | |
e3c4633e | 1505 | |
71661611 | 1506 | int |
6ec1f4e0 | 1507 | ggc_set_mark (const void *p) |
911ab6b9 | 1508 | { |
1509 | page_entry *entry; | |
1510 | unsigned bit, word; | |
1511 | unsigned long mask; | |
1512 | ||
1513 | /* Look up the page on which the object is alloced. If the object | |
1514 | wasn't allocated by the collector, we'll probably die. */ | |
e3691812 | 1515 | entry = lookup_page_table_entry (p); |
0d59b19d | 1516 | gcc_assert (entry); |
911ab6b9 | 1517 | |
1518 | /* Calculate the index of the object on the page; this is its bit | |
1519 | position in the in_use_p bitmap. */ | |
40b9be5e | 1520 | bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order); |
911ab6b9 | 1521 | word = bit / HOST_BITS_PER_LONG; |
1522 | mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG); | |
3cfec666 | 1523 | |
aa40f561 | 1524 | /* If the bit was previously set, skip it. */ |
911ab6b9 | 1525 | if (entry->in_use_p[word] & mask) |
1526 | return 1; | |
1527 | ||
1528 | /* Otherwise set it, and decrement the free object count. */ | |
1529 | entry->in_use_p[word] |= mask; | |
1530 | entry->num_free_objects -= 1; | |
1531 | ||
911ab6b9 | 1532 | if (GGC_DEBUG_LEVEL >= 4) |
1533 | fprintf (G.debug_file, "Marking %p\n", p); | |
1534 | ||
1535 | return 0; | |
1536 | } | |
1537 | ||
3cfec666 | 1538 | /* Return 1 if P has been marked, zero otherwise. |
15d769aa | 1539 | P must have been allocated by the GC allocator; it mustn't point to |
1540 | static objects, stack variables, or memory allocated with malloc. */ | |
1541 | ||
1542 | int | |
6ec1f4e0 | 1543 | ggc_marked_p (const void *p) |
15d769aa | 1544 | { |
1545 | page_entry *entry; | |
1546 | unsigned bit, word; | |
1547 | unsigned long mask; | |
1548 | ||
1549 | /* Look up the page on which the object is alloced. If the object | |
1550 | wasn't allocated by the collector, we'll probably die. */ | |
1551 | entry = lookup_page_table_entry (p); | |
0d59b19d | 1552 | gcc_assert (entry); |
15d769aa | 1553 | |
1554 | /* Calculate the index of the object on the page; this is its bit | |
1555 | position in the in_use_p bitmap. */ | |
40b9be5e | 1556 | bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order); |
15d769aa | 1557 | word = bit / HOST_BITS_PER_LONG; |
1558 | mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG); | |
3cfec666 | 1559 | |
291e3f96 | 1560 | return (entry->in_use_p[word] & mask) != 0; |
15d769aa | 1561 | } |
1562 | ||
e3c4633e | 1563 | /* Return the size of the gc-able object P. */ |
1564 | ||
4e00b6fd | 1565 | size_t |
6ec1f4e0 | 1566 | ggc_get_size (const void *p) |
4e00b6fd | 1567 | { |
1568 | page_entry *pe = lookup_page_table_entry (p); | |
2f6aecaf | 1569 | return OBJECT_SIZE (pe->order); |
4e00b6fd | 1570 | } |
c4e03242 | 1571 | |
1572 | /* Release the memory for object P. */ | |
1573 | ||
1574 | void | |
1575 | ggc_free (void *p) | |
1576 | { | |
8f359205 | 1577 | if (in_gc) |
1578 | return; | |
1579 | ||
c4e03242 | 1580 | page_entry *pe = lookup_page_table_entry (p); |
1581 | size_t order = pe->order; | |
1582 | size_t size = OBJECT_SIZE (order); | |
1583 | ||
ecd52ea9 | 1584 | if (GATHER_STATISTICS) |
1585 | ggc_free_overhead (p); | |
0ca9a7b6 | 1586 | |
c4e03242 | 1587 | if (GGC_DEBUG_LEVEL >= 3) |
1588 | fprintf (G.debug_file, | |
1589 | "Freeing object, actual size=%lu, at %p on %p\n", | |
1590 | (unsigned long) size, p, (void *) pe); | |
1591 | ||
1592 | #ifdef ENABLE_GC_CHECKING | |
1593 | /* Poison the data, to indicate the data is garbage. */ | |
a7779e75 | 1594 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (p, size)); |
c4e03242 | 1595 | memset (p, 0xa5, size); |
1596 | #endif | |
1597 | /* Let valgrind know the object is free. */ | |
a7779e75 | 1598 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (p, size)); |
c4e03242 | 1599 | |
1600 | #ifdef ENABLE_GC_ALWAYS_COLLECT | |
1601 | /* In the completely-anal-checking mode, we do *not* immediately free | |
48e1416a | 1602 | the data, but instead verify that the data is *actually* not |
c4e03242 | 1603 | reachable the next time we collect. */ |
1604 | { | |
4c36ffe6 | 1605 | struct free_object *fo = XNEW (struct free_object); |
c4e03242 | 1606 | fo->object = p; |
1607 | fo->next = G.free_object_list; | |
1608 | G.free_object_list = fo; | |
1609 | } | |
1610 | #else | |
1611 | { | |
1612 | unsigned int bit_offset, word, bit; | |
1613 | ||
1614 | G.allocated -= size; | |
1615 | ||
1616 | /* Mark the object not-in-use. */ | |
1617 | bit_offset = OFFSET_TO_BIT (((const char *) p) - pe->page, order); | |
1618 | word = bit_offset / HOST_BITS_PER_LONG; | |
1619 | bit = bit_offset % HOST_BITS_PER_LONG; | |
1620 | pe->in_use_p[word] &= ~(1UL << bit); | |
1621 | ||
1622 | if (pe->num_free_objects++ == 0) | |
1623 | { | |
4a755ae7 | 1624 | page_entry *p, *q; |
1625 | ||
c4e03242 | 1626 | /* If the page is completely full, then it's supposed to |
1627 | be after all pages that aren't. Since we've freed one | |
1628 | object from a page that was full, we need to move the | |
48e1416a | 1629 | page to the head of the list. |
c4e03242 | 1630 | |
4a755ae7 | 1631 | PE is the node we want to move. Q is the previous node |
1632 | and P is the next node in the list. */ | |
1633 | q = pe->prev; | |
c4e03242 | 1634 | if (q && q->num_free_objects == 0) |
1635 | { | |
1636 | p = pe->next; | |
4a755ae7 | 1637 | |
c4e03242 | 1638 | q->next = p; |
4a755ae7 | 1639 | |
1640 | /* If PE was at the end of the list, then Q becomes the | |
1641 | new end of the list. If PE was not the end of the | |
1642 | list, then we need to update the PREV field for P. */ | |
c4e03242 | 1643 | if (!p) |
1644 | G.page_tails[order] = q; | |
4a755ae7 | 1645 | else |
1646 | p->prev = q; | |
1647 | ||
1648 | /* Move PE to the head of the list. */ | |
c4e03242 | 1649 | pe->next = G.pages[order]; |
4a755ae7 | 1650 | pe->prev = NULL; |
1651 | G.pages[order]->prev = pe; | |
c4e03242 | 1652 | G.pages[order] = pe; |
1653 | } | |
1654 | ||
1655 | /* Reset the hint bit to point to the only free object. */ | |
1656 | pe->next_bit_hint = bit_offset; | |
1657 | } | |
1658 | } | |
1659 | #endif | |
1660 | } | |
911ab6b9 | 1661 | \f |
40b9be5e | 1662 | /* Subroutine of init_ggc which computes the pair of numbers used to |
1663 | perform division by OBJECT_SIZE (order) and fills in inverse_table[]. | |
1664 | ||
1665 | This algorithm is taken from Granlund and Montgomery's paper | |
1666 | "Division by Invariant Integers using Multiplication" | |
1667 | (Proc. SIGPLAN PLDI, 1994), section 9 (Exact division by | |
1668 | constants). */ | |
1669 | ||
1670 | static void | |
6ec1f4e0 | 1671 | compute_inverse (unsigned order) |
40b9be5e | 1672 | { |
48e1416a | 1673 | size_t size, inv; |
2c06e494 | 1674 | unsigned int e; |
ff34fd94 | 1675 | |
40b9be5e | 1676 | size = OBJECT_SIZE (order); |
1677 | e = 0; | |
1678 | while (size % 2 == 0) | |
1679 | { | |
1680 | e++; | |
1681 | size >>= 1; | |
1682 | } | |
e3c4633e | 1683 | |
40b9be5e | 1684 | inv = size; |
1685 | while (inv * size != 1) | |
1686 | inv = inv * (2 - inv*size); | |
1687 | ||
1688 | DIV_MULT (order) = inv; | |
1689 | DIV_SHIFT (order) = e; | |
1690 | } | |
1691 | ||
1692 | /* Initialize the ggc-mmap allocator. */ | |
911ab6b9 | 1693 | void |
6ec1f4e0 | 1694 | init_ggc (void) |
911ab6b9 | 1695 | { |
415309e2 | 1696 | static bool init_p = false; |
2f6aecaf | 1697 | unsigned order; |
1698 | ||
415309e2 | 1699 | if (init_p) |
1700 | return; | |
1701 | init_p = true; | |
1702 | ||
9af5ce0c | 1703 | G.pagesize = getpagesize (); |
911ab6b9 | 1704 | G.lg_pagesize = exact_log2 (G.pagesize); |
1705 | ||
901dfcc7 | 1706 | #ifdef HAVE_MMAP_DEV_ZERO |
911ab6b9 | 1707 | G.dev_zero_fd = open ("/dev/zero", O_RDONLY); |
1708 | if (G.dev_zero_fd == -1) | |
3a2aee0e | 1709 | internal_error ("open /dev/zero: %m"); |
911ab6b9 | 1710 | #endif |
1711 | ||
1712 | #if 0 | |
1713 | G.debug_file = fopen ("ggc-mmap.debug", "w"); | |
1714 | #else | |
1715 | G.debug_file = stdout; | |
1716 | #endif | |
1717 | ||
901dfcc7 | 1718 | #ifdef USING_MMAP |
42f8e268 | 1719 | /* StunOS has an amazing off-by-one error for the first mmap allocation |
1720 | after fiddling with RLIMIT_STACK. The result, as hard as it is to | |
1721 | believe, is an unaligned page allocation, which would cause us to | |
1722 | hork badly if we tried to use it. */ | |
1723 | { | |
4a2f812e | 1724 | char *p = alloc_anon (NULL, G.pagesize, true); |
901dfcc7 | 1725 | struct page_entry *e; |
337c992b | 1726 | if ((uintptr_t)p & (G.pagesize - 1)) |
42f8e268 | 1727 | { |
1728 | /* How losing. Discard this one and try another. If we still | |
1729 | can't get something useful, give up. */ | |
1730 | ||
4a2f812e | 1731 | p = alloc_anon (NULL, G.pagesize, true); |
337c992b | 1732 | gcc_assert (!((uintptr_t)p & (G.pagesize - 1))); |
42f8e268 | 1733 | } |
901dfcc7 | 1734 | |
aa40f561 | 1735 | /* We have a good page, might as well hold onto it... */ |
4c36ffe6 | 1736 | e = XCNEW (struct page_entry); |
901dfcc7 | 1737 | e->bytes = G.pagesize; |
1738 | e->page = p; | |
1739 | e->next = G.free_pages; | |
1740 | G.free_pages = e; | |
42f8e268 | 1741 | } |
1742 | #endif | |
2f6aecaf | 1743 | |
1744 | /* Initialize the object size table. */ | |
1745 | for (order = 0; order < HOST_BITS_PER_PTR; ++order) | |
1746 | object_size_table[order] = (size_t) 1 << order; | |
1747 | for (order = HOST_BITS_PER_PTR; order < NUM_ORDERS; ++order) | |
918edee0 | 1748 | { |
1749 | size_t s = extra_order_size_table[order - HOST_BITS_PER_PTR]; | |
5da2078a | 1750 | |
1751 | /* If S is not a multiple of the MAX_ALIGNMENT, then round it up | |
1752 | so that we're sure of getting aligned memory. */ | |
1753 | s = ROUND_UP (s, MAX_ALIGNMENT); | |
918edee0 | 1754 | object_size_table[order] = s; |
1755 | } | |
2f6aecaf | 1756 | |
40b9be5e | 1757 | /* Initialize the objects-per-page and inverse tables. */ |
2f6aecaf | 1758 | for (order = 0; order < NUM_ORDERS; ++order) |
1759 | { | |
1760 | objects_per_page_table[order] = G.pagesize / OBJECT_SIZE (order); | |
1761 | if (objects_per_page_table[order] == 0) | |
1762 | objects_per_page_table[order] = 1; | |
40b9be5e | 1763 | compute_inverse (order); |
2f6aecaf | 1764 | } |
1765 | ||
1766 | /* Reset the size_lookup array to put appropriately sized objects in | |
1767 | the special orders. All objects bigger than the previous power | |
1768 | of two, but no greater than the special size, should go in the | |
5da2078a | 1769 | new order. */ |
2f6aecaf | 1770 | for (order = HOST_BITS_PER_PTR; order < NUM_ORDERS; ++order) |
1771 | { | |
5da2078a | 1772 | int o; |
1773 | int i; | |
76e1b933 | 1774 | |
f68513d3 | 1775 | i = OBJECT_SIZE (order); |
1776 | if (i >= NUM_SIZE_LOOKUP) | |
1777 | continue; | |
1778 | ||
1779 | for (o = size_lookup[i]; o == size_lookup [i]; --i) | |
5da2078a | 1780 | size_lookup[i] = order; |
1781 | } | |
8c14f57e | 1782 | |
76e1b933 | 1783 | G.depth_in_use = 0; |
1784 | G.depth_max = 10; | |
4c36ffe6 | 1785 | G.depth = XNEWVEC (unsigned int, G.depth_max); |
76e1b933 | 1786 | |
1787 | G.by_depth_in_use = 0; | |
1788 | G.by_depth_max = INITIAL_PTE_COUNT; | |
4c36ffe6 | 1789 | G.by_depth = XNEWVEC (page_entry *, G.by_depth_max); |
1790 | G.save_in_use = XNEWVEC (unsigned long *, G.by_depth_max); | |
911ab6b9 | 1791 | } |
1792 | ||
c10b9b1c | 1793 | /* Merge the SAVE_IN_USE_P and IN_USE_P arrays in P so that IN_USE_P |
1794 | reflects reality. Recalculate NUM_FREE_OBJECTS as well. */ | |
1795 | ||
1796 | static void | |
6ec1f4e0 | 1797 | ggc_recalculate_in_use_p (page_entry *p) |
c10b9b1c | 1798 | { |
1799 | unsigned int i; | |
1800 | size_t num_objects; | |
1801 | ||
3cfec666 | 1802 | /* Because the past-the-end bit in in_use_p is always set, we |
c10b9b1c | 1803 | pretend there is one additional object. */ |
573aba85 | 1804 | num_objects = OBJECTS_IN_PAGE (p) + 1; |
c10b9b1c | 1805 | |
1806 | /* Reset the free object count. */ | |
1807 | p->num_free_objects = num_objects; | |
1808 | ||
1809 | /* Combine the IN_USE_P and SAVE_IN_USE_P arrays. */ | |
3cfec666 | 1810 | for (i = 0; |
2f6aecaf | 1811 | i < CEIL (BITMAP_SIZE (num_objects), |
1812 | sizeof (*p->in_use_p)); | |
c10b9b1c | 1813 | ++i) |
1814 | { | |
1815 | unsigned long j; | |
1816 | ||
1817 | /* Something is in use if it is marked, or if it was in use in a | |
1818 | context further down the context stack. */ | |
76e1b933 | 1819 | p->in_use_p[i] |= save_in_use_p (p)[i]; |
c10b9b1c | 1820 | |
1821 | /* Decrement the free object count for every object allocated. */ | |
1822 | for (j = p->in_use_p[i]; j; j >>= 1) | |
1823 | p->num_free_objects -= (j & 1); | |
1824 | } | |
1825 | ||
0d59b19d | 1826 | gcc_assert (p->num_free_objects < num_objects); |
c10b9b1c | 1827 | } |
911ab6b9 | 1828 | \f |
e3c4633e | 1829 | /* Unmark all objects. */ |
1830 | ||
c4e03242 | 1831 | static void |
6ec1f4e0 | 1832 | clear_marks (void) |
911ab6b9 | 1833 | { |
1834 | unsigned order; | |
1835 | ||
2f6aecaf | 1836 | for (order = 2; order < NUM_ORDERS; order++) |
911ab6b9 | 1837 | { |
911ab6b9 | 1838 | page_entry *p; |
1839 | ||
1840 | for (p = G.pages[order]; p != NULL; p = p->next) | |
1841 | { | |
573aba85 | 1842 | size_t num_objects = OBJECTS_IN_PAGE (p); |
1843 | size_t bitmap_size = BITMAP_SIZE (num_objects + 1); | |
1844 | ||
911ab6b9 | 1845 | /* The data should be page-aligned. */ |
337c992b | 1846 | gcc_assert (!((uintptr_t) p->page & (G.pagesize - 1))); |
911ab6b9 | 1847 | |
1848 | /* Pages that aren't in the topmost context are not collected; | |
1849 | nevertheless, we need their in-use bit vectors to store GC | |
1850 | marks. So, back them up first. */ | |
c10b9b1c | 1851 | if (p->context_depth < G.context_depth) |
911ab6b9 | 1852 | { |
76e1b933 | 1853 | if (! save_in_use_p (p)) |
4077bf7a | 1854 | save_in_use_p (p) = XNEWVAR (unsigned long, bitmap_size); |
76e1b933 | 1855 | memcpy (save_in_use_p (p), p->in_use_p, bitmap_size); |
911ab6b9 | 1856 | } |
1857 | ||
1858 | /* Reset reset the number of free objects and clear the | |
1859 | in-use bits. These will be adjusted by mark_obj. */ | |
1860 | p->num_free_objects = num_objects; | |
1861 | memset (p->in_use_p, 0, bitmap_size); | |
1862 | ||
1863 | /* Make sure the one-past-the-end bit is always set. */ | |
3cfec666 | 1864 | p->in_use_p[num_objects / HOST_BITS_PER_LONG] |
911ab6b9 | 1865 | = ((unsigned long) 1 << (num_objects % HOST_BITS_PER_LONG)); |
1866 | } | |
1867 | } | |
1868 | } | |
1869 | ||
92960204 | 1870 | /* Check if any blocks with a registered finalizer have become unmarked. If so |
1871 | run the finalizer and unregister it because the block is about to be freed. | |
1872 | Note that no garantee is made about what order finalizers will run in so | |
1873 | touching other objects in gc memory is extremely unwise. */ | |
1874 | ||
92f06184 | 1875 | static void |
1876 | ggc_handle_finalizers () | |
1877 | { | |
1878 | if (G.context_depth != 0) | |
1879 | return; | |
1880 | ||
1881 | unsigned length = G.finalizers.length (); | |
1882 | for (unsigned int i = 0; i < length;) | |
1883 | { | |
1884 | finalizer &f = G.finalizers[i]; | |
1885 | if (!ggc_marked_p (f.addr ())) | |
1886 | { | |
1887 | f.call (); | |
1888 | G.finalizers.unordered_remove (i); | |
1889 | length--; | |
1890 | } | |
1891 | else | |
1892 | i++; | |
1893 | } | |
1894 | ||
1895 | ||
1896 | length = G.vec_finalizers.length (); | |
1897 | for (unsigned int i = 0; i < length;) | |
1898 | { | |
1899 | vec_finalizer &f = G.vec_finalizers[i]; | |
1900 | if (!ggc_marked_p (f.addr ())) | |
1901 | { | |
1902 | f.call (); | |
1903 | G.vec_finalizers.unordered_remove (i); | |
1904 | length--; | |
1905 | } | |
1906 | else | |
1907 | i++; | |
1908 | } | |
1909 | } | |
1910 | ||
e3c4633e | 1911 | /* Free all empty pages. Partially empty pages need no attention |
1912 | because the `mark' bit doubles as an `unused' bit. */ | |
1913 | ||
c4e03242 | 1914 | static void |
6ec1f4e0 | 1915 | sweep_pages (void) |
911ab6b9 | 1916 | { |
1917 | unsigned order; | |
1918 | ||
2f6aecaf | 1919 | for (order = 2; order < NUM_ORDERS; order++) |
911ab6b9 | 1920 | { |
1921 | /* The last page-entry to consider, regardless of entries | |
1922 | placed at the end of the list. */ | |
1923 | page_entry * const last = G.page_tails[order]; | |
1924 | ||
573aba85 | 1925 | size_t num_objects; |
9a2e8b0a | 1926 | size_t live_objects; |
911ab6b9 | 1927 | page_entry *p, *previous; |
1928 | int done; | |
3cfec666 | 1929 | |
911ab6b9 | 1930 | p = G.pages[order]; |
1931 | if (p == NULL) | |
1932 | continue; | |
1933 | ||
1934 | previous = NULL; | |
1935 | do | |
1936 | { | |
1937 | page_entry *next = p->next; | |
1938 | ||
1939 | /* Loop until all entries have been examined. */ | |
1940 | done = (p == last); | |
6ec1f4e0 | 1941 | |
573aba85 | 1942 | num_objects = OBJECTS_IN_PAGE (p); |
911ab6b9 | 1943 | |
9a2e8b0a | 1944 | /* Add all live objects on this page to the count of |
1945 | allocated memory. */ | |
1946 | live_objects = num_objects - p->num_free_objects; | |
1947 | ||
2f6aecaf | 1948 | G.allocated += OBJECT_SIZE (order) * live_objects; |
9a2e8b0a | 1949 | |
911ab6b9 | 1950 | /* Only objects on pages in the topmost context should get |
1951 | collected. */ | |
1952 | if (p->context_depth < G.context_depth) | |
1953 | ; | |
1954 | ||
1955 | /* Remove the page if it's empty. */ | |
9a2e8b0a | 1956 | else if (live_objects == 0) |
911ab6b9 | 1957 | { |
4a755ae7 | 1958 | /* If P was the first page in the list, then NEXT |
1959 | becomes the new first page in the list, otherwise | |
1960 | splice P out of the forward pointers. */ | |
911ab6b9 | 1961 | if (! previous) |
1962 | G.pages[order] = next; | |
1963 | else | |
1964 | previous->next = next; | |
48e1416a | 1965 | |
4a755ae7 | 1966 | /* Splice P out of the back pointers too. */ |
1967 | if (next) | |
1968 | next->prev = previous; | |
911ab6b9 | 1969 | |
1970 | /* Are we removing the last element? */ | |
1971 | if (p == G.page_tails[order]) | |
1972 | G.page_tails[order] = previous; | |
1973 | free_page (p); | |
1974 | p = previous; | |
1975 | } | |
1976 | ||
1977 | /* If the page is full, move it to the end. */ | |
1978 | else if (p->num_free_objects == 0) | |
1979 | { | |
1980 | /* Don't move it if it's already at the end. */ | |
1981 | if (p != G.page_tails[order]) | |
1982 | { | |
1983 | /* Move p to the end of the list. */ | |
1984 | p->next = NULL; | |
4a755ae7 | 1985 | p->prev = G.page_tails[order]; |
911ab6b9 | 1986 | G.page_tails[order]->next = p; |
1987 | ||
1988 | /* Update the tail pointer... */ | |
1989 | G.page_tails[order] = p; | |
1990 | ||
1991 | /* ... and the head pointer, if necessary. */ | |
1992 | if (! previous) | |
1993 | G.pages[order] = next; | |
1994 | else | |
1995 | previous->next = next; | |
4a755ae7 | 1996 | |
1997 | /* And update the backpointer in NEXT if necessary. */ | |
1998 | if (next) | |
1999 | next->prev = previous; | |
2000 | ||
911ab6b9 | 2001 | p = previous; |
2002 | } | |
2003 | } | |
2004 | ||
2005 | /* If we've fallen through to here, it's a page in the | |
2006 | topmost context that is neither full nor empty. Such a | |
2007 | page must precede pages at lesser context depth in the | |
2008 | list, so move it to the head. */ | |
2009 | else if (p != G.pages[order]) | |
2010 | { | |
2011 | previous->next = p->next; | |
4a755ae7 | 2012 | |
2013 | /* Update the backchain in the next node if it exists. */ | |
2014 | if (p->next) | |
2015 | p->next->prev = previous; | |
2016 | ||
2017 | /* Move P to the head of the list. */ | |
911ab6b9 | 2018 | p->next = G.pages[order]; |
4a755ae7 | 2019 | p->prev = NULL; |
2020 | G.pages[order]->prev = p; | |
2021 | ||
2022 | /* Update the head pointer. */ | |
911ab6b9 | 2023 | G.pages[order] = p; |
4a755ae7 | 2024 | |
911ab6b9 | 2025 | /* Are we moving the last element? */ |
2026 | if (G.page_tails[order] == p) | |
2027 | G.page_tails[order] = previous; | |
2028 | p = previous; | |
2029 | } | |
2030 | ||
2031 | previous = p; | |
2032 | p = next; | |
3cfec666 | 2033 | } |
911ab6b9 | 2034 | while (! done); |
c10b9b1c | 2035 | |
2036 | /* Now, restore the in_use_p vectors for any pages from contexts | |
2037 | other than the current one. */ | |
2038 | for (p = G.pages[order]; p; p = p->next) | |
2039 | if (p->context_depth != G.context_depth) | |
2040 | ggc_recalculate_in_use_p (p); | |
911ab6b9 | 2041 | } |
2042 | } | |
2043 | ||
2a3edec5 | 2044 | #ifdef ENABLE_GC_CHECKING |
e3c4633e | 2045 | /* Clobber all free objects. */ |
2046 | ||
c4e03242 | 2047 | static void |
6ec1f4e0 | 2048 | poison_pages (void) |
911ab6b9 | 2049 | { |
2050 | unsigned order; | |
2051 | ||
2f6aecaf | 2052 | for (order = 2; order < NUM_ORDERS; order++) |
911ab6b9 | 2053 | { |
2f6aecaf | 2054 | size_t size = OBJECT_SIZE (order); |
911ab6b9 | 2055 | page_entry *p; |
2056 | ||
2057 | for (p = G.pages[order]; p != NULL; p = p->next) | |
2058 | { | |
573aba85 | 2059 | size_t num_objects; |
911ab6b9 | 2060 | size_t i; |
2d517b2f | 2061 | |
2062 | if (p->context_depth != G.context_depth) | |
2063 | /* Since we don't do any collection for pages in pushed | |
2064 | contexts, there's no need to do any poisoning. And | |
2065 | besides, the IN_USE_P array isn't valid until we pop | |
2066 | contexts. */ | |
2067 | continue; | |
2068 | ||
573aba85 | 2069 | num_objects = OBJECTS_IN_PAGE (p); |
911ab6b9 | 2070 | for (i = 0; i < num_objects; i++) |
2071 | { | |
2072 | size_t word, bit; | |
2073 | word = i / HOST_BITS_PER_LONG; | |
2074 | bit = i % HOST_BITS_PER_LONG; | |
2075 | if (((p->in_use_p[word] >> bit) & 1) == 0) | |
dd359afe | 2076 | { |
2077 | char *object = p->page + i * size; | |
2078 | ||
2079 | /* Keep poison-by-write when we expect to use Valgrind, | |
2080 | so the exact same memory semantics is kept, in case | |
2081 | there are memory errors. We override this request | |
2082 | below. */ | |
a7779e75 | 2083 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (object, |
2084 | size)); | |
dd359afe | 2085 | memset (object, 0xa5, size); |
2086 | ||
2087 | /* Drop the handle to avoid handle leak. */ | |
a7779e75 | 2088 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (object, size)); |
dd359afe | 2089 | } |
911ab6b9 | 2090 | } |
2091 | } | |
2092 | } | |
2093 | } | |
c4e03242 | 2094 | #else |
2095 | #define poison_pages() | |
2096 | #endif | |
2097 | ||
2098 | #ifdef ENABLE_GC_ALWAYS_COLLECT | |
2099 | /* Validate that the reportedly free objects actually are. */ | |
2100 | ||
2101 | static void | |
2102 | validate_free_objects (void) | |
2103 | { | |
2104 | struct free_object *f, *next, *still_free = NULL; | |
2105 | ||
2106 | for (f = G.free_object_list; f ; f = next) | |
2107 | { | |
2108 | page_entry *pe = lookup_page_table_entry (f->object); | |
2109 | size_t bit, word; | |
2110 | ||
2111 | bit = OFFSET_TO_BIT ((char *)f->object - pe->page, pe->order); | |
2112 | word = bit / HOST_BITS_PER_LONG; | |
2113 | bit = bit % HOST_BITS_PER_LONG; | |
2114 | next = f->next; | |
2115 | ||
2116 | /* Make certain it isn't visible from any root. Notice that we | |
2117 | do this check before sweep_pages merges save_in_use_p. */ | |
0d59b19d | 2118 | gcc_assert (!(pe->in_use_p[word] & (1UL << bit))); |
c4e03242 | 2119 | |
2120 | /* If the object comes from an outer context, then retain the | |
2121 | free_object entry, so that we can verify that the address | |
2122 | isn't live on the stack in some outer context. */ | |
2123 | if (pe->context_depth != G.context_depth) | |
2124 | { | |
2125 | f->next = still_free; | |
2126 | still_free = f; | |
2127 | } | |
2128 | else | |
2129 | free (f); | |
2130 | } | |
2131 | ||
2132 | G.free_object_list = still_free; | |
2133 | } | |
2134 | #else | |
2135 | #define validate_free_objects() | |
911ab6b9 | 2136 | #endif |
2137 | ||
e3c4633e | 2138 | /* Top level mark-and-sweep routine. */ |
2139 | ||
911ab6b9 | 2140 | void |
6ec1f4e0 | 2141 | ggc_collect (void) |
911ab6b9 | 2142 | { |
911ab6b9 | 2143 | /* Avoid frequent unnecessary work by skipping collection if the |
2144 | total allocations haven't expanded much since the last | |
2145 | collection. */ | |
83142a4c | 2146 | float allocated_last_gc = |
2a3edec5 | 2147 | MAX (G.allocated_last_gc, (size_t)PARAM_VALUE (GGC_MIN_HEAPSIZE) * 1024); |
2148 | ||
83142a4c | 2149 | float min_expand = allocated_last_gc * PARAM_VALUE (GGC_MIN_EXPAND) / 100; |
0ca9a7b6 | 2150 | if (G.allocated < allocated_last_gc + min_expand && !ggc_force_collect) |
911ab6b9 | 2151 | return; |
911ab6b9 | 2152 | |
74d2af64 | 2153 | timevar_push (TV_GC); |
911ab6b9 | 2154 | if (!quiet_flag) |
90856340 | 2155 | fprintf (stderr, " {GC %luk -> ", (unsigned long) G.allocated / 1024); |
c4e03242 | 2156 | if (GGC_DEBUG_LEVEL >= 2) |
2157 | fprintf (G.debug_file, "BEGIN COLLECTING\n"); | |
911ab6b9 | 2158 | |
9a2e8b0a | 2159 | /* Zero the total allocated bytes. This will be recalculated in the |
2160 | sweep phase. */ | |
911ab6b9 | 2161 | G.allocated = 0; |
2162 | ||
3cfec666 | 2163 | /* Release the pages we freed the last time we collected, but didn't |
911ab6b9 | 2164 | reuse in the interim. */ |
2165 | release_pages (); | |
2166 | ||
598638e2 | 2167 | /* Indicate that we've seen collections at this context depth. */ |
2168 | G.context_depth_collections = ((unsigned long)1 << (G.context_depth + 1)) - 1; | |
2169 | ||
740cd0be | 2170 | invoke_plugin_callbacks (PLUGIN_GGC_START, NULL); |
2171 | ||
8f359205 | 2172 | in_gc = true; |
911ab6b9 | 2173 | clear_marks (); |
2174 | ggc_mark_roots (); | |
92f06184 | 2175 | ggc_handle_finalizers (); |
ecd52ea9 | 2176 | |
2177 | if (GATHER_STATISTICS) | |
2178 | ggc_prune_overhead_list (); | |
2179 | ||
911ab6b9 | 2180 | poison_pages (); |
c4e03242 | 2181 | validate_free_objects (); |
e3c4633e | 2182 | sweep_pages (); |
2183 | ||
8f359205 | 2184 | in_gc = false; |
911ab6b9 | 2185 | G.allocated_last_gc = G.allocated; |
2186 | ||
740cd0be | 2187 | invoke_plugin_callbacks (PLUGIN_GGC_END, NULL); |
2188 | ||
74d2af64 | 2189 | timevar_pop (TV_GC); |
911ab6b9 | 2190 | |
911ab6b9 | 2191 | if (!quiet_flag) |
74d2af64 | 2192 | fprintf (stderr, "%luk}", (unsigned long) G.allocated / 1024); |
c4e03242 | 2193 | if (GGC_DEBUG_LEVEL >= 2) |
2194 | fprintf (G.debug_file, "END COLLECTING\n"); | |
911ab6b9 | 2195 | } |
4e00b6fd | 2196 | |
4f78e0a8 | 2197 | /* Assume that all GGC memory is reachable and grow the limits for next collection. |
2198 | With checking, trigger GGC so -Q compilation outputs how much of memory really is | |
2199 | reachable. */ | |
2200 | ||
2201 | void | |
2202 | ggc_grow (void) | |
2203 | { | |
382ecba7 | 2204 | if (!flag_checking) |
2205 | G.allocated_last_gc = MAX (G.allocated_last_gc, | |
2206 | G.allocated); | |
2207 | else | |
2208 | ggc_collect (); | |
4f78e0a8 | 2209 | if (!quiet_flag) |
2210 | fprintf (stderr, " {GC start %luk} ", (unsigned long) G.allocated / 1024); | |
2211 | } | |
2212 | ||
4e00b6fd | 2213 | /* Print allocation statistics. */ |
2a8997e8 | 2214 | #define SCALE(x) ((unsigned long) ((x) < 1024*10 \ |
2215 | ? (x) \ | |
2216 | : ((x) < 1024*1024*10 \ | |
2217 | ? (x) / 1024 \ | |
2218 | : (x) / (1024*1024)))) | |
0ca9a7b6 | 2219 | #define STAT_LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M')) |
4e00b6fd | 2220 | |
2221 | void | |
6ec1f4e0 | 2222 | ggc_print_statistics (void) |
4e00b6fd | 2223 | { |
2224 | struct ggc_statistics stats; | |
c10b9b1c | 2225 | unsigned int i; |
2a8997e8 | 2226 | size_t total_overhead = 0; |
4e00b6fd | 2227 | |
2228 | /* Clear the statistics. */ | |
3e9d8cee | 2229 | memset (&stats, 0, sizeof (stats)); |
3cfec666 | 2230 | |
4e00b6fd | 2231 | /* Make sure collection will really occur. */ |
2232 | G.allocated_last_gc = 0; | |
2233 | ||
2234 | /* Collect and print the statistics common across collectors. */ | |
2a8997e8 | 2235 | ggc_print_common_statistics (stderr, &stats); |
4e00b6fd | 2236 | |
c10b9b1c | 2237 | /* Release free pages so that we will not count the bytes allocated |
2238 | there as part of the total allocated memory. */ | |
2239 | release_pages (); | |
2240 | ||
3cfec666 | 2241 | /* Collect some information about the various sizes of |
4e00b6fd | 2242 | allocation. */ |
86736f9e | 2243 | fprintf (stderr, |
2244 | "Memory still allocated at the end of the compilation process\n"); | |
98cc198b | 2245 | fprintf (stderr, "%-8s %10s %10s %10s\n", |
f806fb68 | 2246 | "Size", "Allocated", "Used", "Overhead"); |
2f6aecaf | 2247 | for (i = 0; i < NUM_ORDERS; ++i) |
4e00b6fd | 2248 | { |
2249 | page_entry *p; | |
2250 | size_t allocated; | |
2251 | size_t in_use; | |
2a8997e8 | 2252 | size_t overhead; |
4e00b6fd | 2253 | |
2254 | /* Skip empty entries. */ | |
2255 | if (!G.pages[i]) | |
2256 | continue; | |
2257 | ||
2a8997e8 | 2258 | overhead = allocated = in_use = 0; |
4e00b6fd | 2259 | |
2260 | /* Figure out the total number of bytes allocated for objects of | |
2a8997e8 | 2261 | this size, and how many of them are actually in use. Also figure |
2262 | out how much memory the page table is using. */ | |
4e00b6fd | 2263 | for (p = G.pages[i]; p; p = p->next) |
2264 | { | |
2265 | allocated += p->bytes; | |
6ec1f4e0 | 2266 | in_use += |
573aba85 | 2267 | (OBJECTS_IN_PAGE (p) - p->num_free_objects) * OBJECT_SIZE (i); |
2a8997e8 | 2268 | |
2269 | overhead += (sizeof (page_entry) - sizeof (long) | |
573aba85 | 2270 | + BITMAP_SIZE (OBJECTS_IN_PAGE (p) + 1)); |
4e00b6fd | 2271 | } |
98cc198b | 2272 | fprintf (stderr, "%-8lu %10lu%c %10lu%c %10lu%c\n", |
29e7390a | 2273 | (unsigned long) OBJECT_SIZE (i), |
0ca9a7b6 | 2274 | SCALE (allocated), STAT_LABEL (allocated), |
2275 | SCALE (in_use), STAT_LABEL (in_use), | |
2276 | SCALE (overhead), STAT_LABEL (overhead)); | |
2a8997e8 | 2277 | total_overhead += overhead; |
4e00b6fd | 2278 | } |
98cc198b | 2279 | fprintf (stderr, "%-8s %10lu%c %10lu%c %10lu%c\n", "Total", |
0ca9a7b6 | 2280 | SCALE (G.bytes_mapped), STAT_LABEL (G.bytes_mapped), |
9af5ce0c | 2281 | SCALE (G.allocated), STAT_LABEL (G.allocated), |
0ca9a7b6 | 2282 | SCALE (total_overhead), STAT_LABEL (total_overhead)); |
b7257530 | 2283 | |
ecd52ea9 | 2284 | if (GATHER_STATISTICS) |
2285 | { | |
98cc198b | 2286 | fprintf (stderr, "\nTotal allocations and overheads during " |
2287 | "the compilation process\n"); | |
ecd52ea9 | 2288 | |
98cc198b | 2289 | fprintf (stderr, "Total Overhead: %10" |
2290 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_overhead); | |
2291 | fprintf (stderr, "Total Allocated: %10" | |
2292 | HOST_LONG_LONG_FORMAT "d\n", | |
ecd52ea9 | 2293 | G.stats.total_allocated); |
2294 | ||
98cc198b | 2295 | fprintf (stderr, "Total Overhead under 32B: %10" |
2296 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_overhead_under32); | |
2297 | fprintf (stderr, "Total Allocated under 32B: %10" | |
2298 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_allocated_under32); | |
2299 | fprintf (stderr, "Total Overhead under 64B: %10" | |
2300 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_overhead_under64); | |
2301 | fprintf (stderr, "Total Allocated under 64B: %10" | |
2302 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_allocated_under64); | |
2303 | fprintf (stderr, "Total Overhead under 128B: %10" | |
2304 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_overhead_under128); | |
2305 | fprintf (stderr, "Total Allocated under 128B: %10" | |
2306 | HOST_LONG_LONG_FORMAT "d\n", G.stats.total_allocated_under128); | |
ecd52ea9 | 2307 | |
2308 | for (i = 0; i < NUM_ORDERS; i++) | |
2309 | if (G.stats.total_allocated_per_order[i]) | |
2310 | { | |
98cc198b | 2311 | fprintf (stderr, "Total Overhead page size %9lu: %10" |
2312 | HOST_LONG_LONG_FORMAT "d\n", | |
ecd52ea9 | 2313 | (unsigned long) OBJECT_SIZE (i), |
2314 | G.stats.total_overhead_per_order[i]); | |
98cc198b | 2315 | fprintf (stderr, "Total Allocated page size %9lu: %10" |
2316 | HOST_LONG_LONG_FORMAT "d\n", | |
ecd52ea9 | 2317 | (unsigned long) OBJECT_SIZE (i), |
2318 | G.stats.total_allocated_per_order[i]); | |
2319 | } | |
b7257530 | 2320 | } |
4e00b6fd | 2321 | } |
573aba85 | 2322 | \f |
0b09525f | 2323 | struct ggc_pch_ondisk |
2324 | { | |
2325 | unsigned totals[NUM_ORDERS]; | |
2326 | }; | |
2327 | ||
573aba85 | 2328 | struct ggc_pch_data |
2329 | { | |
0b09525f | 2330 | struct ggc_pch_ondisk d; |
337c992b | 2331 | uintptr_t base[NUM_ORDERS]; |
573aba85 | 2332 | size_t written[NUM_ORDERS]; |
2333 | }; | |
2334 | ||
2335 | struct ggc_pch_data * | |
6ec1f4e0 | 2336 | init_ggc_pch (void) |
573aba85 | 2337 | { |
4c36ffe6 | 2338 | return XCNEW (struct ggc_pch_data); |
573aba85 | 2339 | } |
2340 | ||
6ec1f4e0 | 2341 | void |
2342 | ggc_pch_count_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, | |
5cc13354 | 2343 | size_t size, bool is_string ATTRIBUTE_UNUSED) |
573aba85 | 2344 | { |
2345 | unsigned order; | |
2346 | ||
f68513d3 | 2347 | if (size < NUM_SIZE_LOOKUP) |
573aba85 | 2348 | order = size_lookup[size]; |
2349 | else | |
2350 | { | |
1c2a6a66 | 2351 | order = 10; |
573aba85 | 2352 | while (size > OBJECT_SIZE (order)) |
2353 | order++; | |
2354 | } | |
6ec1f4e0 | 2355 | |
573aba85 | 2356 | d->d.totals[order]++; |
2357 | } | |
6ec1f4e0 | 2358 | |
573aba85 | 2359 | size_t |
6ec1f4e0 | 2360 | ggc_pch_total_size (struct ggc_pch_data *d) |
573aba85 | 2361 | { |
2362 | size_t a = 0; | |
2363 | unsigned i; | |
2364 | ||
2365 | for (i = 0; i < NUM_ORDERS; i++) | |
25a28b44 | 2366 | a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i)); |
573aba85 | 2367 | return a; |
2368 | } | |
2369 | ||
2370 | void | |
6ec1f4e0 | 2371 | ggc_pch_this_base (struct ggc_pch_data *d, void *base) |
573aba85 | 2372 | { |
337c992b | 2373 | uintptr_t a = (uintptr_t) base; |
573aba85 | 2374 | unsigned i; |
6ec1f4e0 | 2375 | |
573aba85 | 2376 | for (i = 0; i < NUM_ORDERS; i++) |
2377 | { | |
2378 | d->base[i] = a; | |
25a28b44 | 2379 | a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i)); |
573aba85 | 2380 | } |
2381 | } | |
2382 | ||
2383 | ||
2384 | char * | |
6ec1f4e0 | 2385 | ggc_pch_alloc_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, |
5cc13354 | 2386 | size_t size, bool is_string ATTRIBUTE_UNUSED) |
573aba85 | 2387 | { |
2388 | unsigned order; | |
2389 | char *result; | |
6ec1f4e0 | 2390 | |
f68513d3 | 2391 | if (size < NUM_SIZE_LOOKUP) |
573aba85 | 2392 | order = size_lookup[size]; |
2393 | else | |
2394 | { | |
1c2a6a66 | 2395 | order = 10; |
573aba85 | 2396 | while (size > OBJECT_SIZE (order)) |
2397 | order++; | |
2398 | } | |
2399 | ||
2400 | result = (char *) d->base[order]; | |
2401 | d->base[order] += OBJECT_SIZE (order); | |
2402 | return result; | |
2403 | } | |
2404 | ||
6ec1f4e0 | 2405 | void |
2406 | ggc_pch_prepare_write (struct ggc_pch_data *d ATTRIBUTE_UNUSED, | |
2407 | FILE *f ATTRIBUTE_UNUSED) | |
573aba85 | 2408 | { |
2409 | /* Nothing to do. */ | |
2410 | } | |
2411 | ||
2412 | void | |
98044fac | 2413 | ggc_pch_write_object (struct ggc_pch_data *d, |
6ec1f4e0 | 2414 | FILE *f, void *x, void *newx ATTRIBUTE_UNUSED, |
7d60cc60 | 2415 | size_t size, bool is_string ATTRIBUTE_UNUSED) |
573aba85 | 2416 | { |
2417 | unsigned order; | |
1a7c0ccb | 2418 | static const char emptyBytes[256] = { 0 }; |
573aba85 | 2419 | |
f68513d3 | 2420 | if (size < NUM_SIZE_LOOKUP) |
573aba85 | 2421 | order = size_lookup[size]; |
2422 | else | |
2423 | { | |
1c2a6a66 | 2424 | order = 10; |
573aba85 | 2425 | while (size > OBJECT_SIZE (order)) |
2426 | order++; | |
2427 | } | |
6ec1f4e0 | 2428 | |
573aba85 | 2429 | if (fwrite (x, size, 1, f) != 1) |
c05be867 | 2430 | fatal_error (input_location, "can%'t write PCH file: %m"); |
573aba85 | 2431 | |
89e22a52 | 2432 | /* If SIZE is not the same as OBJECT_SIZE(order), then we need to pad the |
e9efa031 | 2433 | object out to OBJECT_SIZE(order). This happens for strings. */ |
89e22a52 | 2434 | |
2435 | if (size != OBJECT_SIZE (order)) | |
2436 | { | |
9af5ce0c | 2437 | unsigned padding = OBJECT_SIZE (order) - size; |
89e22a52 | 2438 | |
2439 | /* To speed small writes, we use a nulled-out array that's larger | |
2440 | than most padding requests as the source for our null bytes. This | |
2441 | permits us to do the padding with fwrite() rather than fseek(), and | |
822e391f | 2442 | limits the chance the OS may try to flush any outstanding writes. */ |
9af5ce0c | 2443 | if (padding <= sizeof (emptyBytes)) |
89e22a52 | 2444 | { |
2445 | if (fwrite (emptyBytes, 1, padding, f) != padding) | |
c05be867 | 2446 | fatal_error (input_location, "can%'t write PCH file"); |
89e22a52 | 2447 | } |
2448 | else | |
2449 | { | |
e9efa031 | 2450 | /* Larger than our buffer? Just default to fseek. */ |
89e22a52 | 2451 | if (fseek (f, padding, SEEK_CUR) != 0) |
c05be867 | 2452 | fatal_error (input_location, "can%'t write PCH file"); |
89e22a52 | 2453 | } |
2454 | } | |
573aba85 | 2455 | |
2456 | d->written[order]++; | |
2457 | if (d->written[order] == d->d.totals[order] | |
2458 | && fseek (f, ROUND_UP_VALUE (d->d.totals[order] * OBJECT_SIZE (order), | |
2459 | G.pagesize), | |
2460 | SEEK_CUR) != 0) | |
c05be867 | 2461 | fatal_error (input_location, "can%'t write PCH file: %m"); |
573aba85 | 2462 | } |
2463 | ||
2464 | void | |
6ec1f4e0 | 2465 | ggc_pch_finish (struct ggc_pch_data *d, FILE *f) |
573aba85 | 2466 | { |
2467 | if (fwrite (&d->d, sizeof (d->d), 1, f) != 1) | |
c05be867 | 2468 | fatal_error (input_location, "can%'t write PCH file: %m"); |
573aba85 | 2469 | free (d); |
2470 | } | |
2471 | ||
76e1b933 | 2472 | /* Move the PCH PTE entries just added to the end of by_depth, to the |
2473 | front. */ | |
2474 | ||
2475 | static void | |
6ec1f4e0 | 2476 | move_ptes_to_front (int count_old_page_tables, int count_new_page_tables) |
76e1b933 | 2477 | { |
2478 | unsigned i; | |
2479 | ||
2480 | /* First, we swap the new entries to the front of the varrays. */ | |
2481 | page_entry **new_by_depth; | |
2482 | unsigned long **new_save_in_use; | |
2483 | ||
4c36ffe6 | 2484 | new_by_depth = XNEWVEC (page_entry *, G.by_depth_max); |
2485 | new_save_in_use = XNEWVEC (unsigned long *, G.by_depth_max); | |
76e1b933 | 2486 | |
2487 | memcpy (&new_by_depth[0], | |
2488 | &G.by_depth[count_old_page_tables], | |
2489 | count_new_page_tables * sizeof (void *)); | |
2490 | memcpy (&new_by_depth[count_new_page_tables], | |
2491 | &G.by_depth[0], | |
2492 | count_old_page_tables * sizeof (void *)); | |
2493 | memcpy (&new_save_in_use[0], | |
2494 | &G.save_in_use[count_old_page_tables], | |
2495 | count_new_page_tables * sizeof (void *)); | |
2496 | memcpy (&new_save_in_use[count_new_page_tables], | |
2497 | &G.save_in_use[0], | |
2498 | count_old_page_tables * sizeof (void *)); | |
2499 | ||
2500 | free (G.by_depth); | |
2501 | free (G.save_in_use); | |
6ec1f4e0 | 2502 | |
76e1b933 | 2503 | G.by_depth = new_by_depth; |
2504 | G.save_in_use = new_save_in_use; | |
2505 | ||
2506 | /* Now update all the index_by_depth fields. */ | |
2507 | for (i = G.by_depth_in_use; i > 0; --i) | |
2508 | { | |
2509 | page_entry *p = G.by_depth[i-1]; | |
2510 | p->index_by_depth = i-1; | |
2511 | } | |
2512 | ||
2513 | /* And last, we update the depth pointers in G.depth. The first | |
2514 | entry is already 0, and context 0 entries always start at index | |
2515 | 0, so there is nothing to update in the first slot. We need a | |
2516 | second slot, only if we have old ptes, and if we do, they start | |
2517 | at index count_new_page_tables. */ | |
2518 | if (count_old_page_tables) | |
2519 | push_depth (count_new_page_tables); | |
2520 | } | |
2521 | ||
573aba85 | 2522 | void |
6ec1f4e0 | 2523 | ggc_pch_read (FILE *f, void *addr) |
573aba85 | 2524 | { |
2525 | struct ggc_pch_ondisk d; | |
2526 | unsigned i; | |
4077bf7a | 2527 | char *offs = (char *) addr; |
76e1b933 | 2528 | unsigned long count_old_page_tables; |
2529 | unsigned long count_new_page_tables; | |
2530 | ||
2531 | count_old_page_tables = G.by_depth_in_use; | |
2532 | ||
2533 | /* We've just read in a PCH file. So, every object that used to be | |
2534 | allocated is now free. */ | |
573aba85 | 2535 | clear_marks (); |
32bbbaac | 2536 | #ifdef ENABLE_GC_CHECKING |
573aba85 | 2537 | poison_pages (); |
2538 | #endif | |
3fff4d99 | 2539 | /* Since we free all the allocated objects, the free list becomes |
2540 | useless. Validate it now, which will also clear it. */ | |
9af5ce0c | 2541 | validate_free_objects (); |
573aba85 | 2542 | |
2543 | /* No object read from a PCH file should ever be freed. So, set the | |
2544 | context depth to 1, and set the depth of all the currently-allocated | |
2545 | pages to be 1 too. PCH pages will have depth 0. */ | |
0d59b19d | 2546 | gcc_assert (!G.context_depth); |
573aba85 | 2547 | G.context_depth = 1; |
2548 | for (i = 0; i < NUM_ORDERS; i++) | |
2549 | { | |
2550 | page_entry *p; | |
2551 | for (p = G.pages[i]; p != NULL; p = p->next) | |
2552 | p->context_depth = G.context_depth; | |
2553 | } | |
2554 | ||
2555 | /* Allocate the appropriate page-table entries for the pages read from | |
2556 | the PCH file. */ | |
2557 | if (fread (&d, sizeof (d), 1, f) != 1) | |
c05be867 | 2558 | fatal_error (input_location, "can%'t read PCH file: %m"); |
6ec1f4e0 | 2559 | |
573aba85 | 2560 | for (i = 0; i < NUM_ORDERS; i++) |
2561 | { | |
2562 | struct page_entry *entry; | |
2563 | char *pte; | |
2564 | size_t bytes; | |
2565 | size_t num_objs; | |
2566 | size_t j; | |
76e1b933 | 2567 | |
573aba85 | 2568 | if (d.totals[i] == 0) |
2569 | continue; | |
76e1b933 | 2570 | |
25a28b44 | 2571 | bytes = PAGE_ALIGN (d.totals[i] * OBJECT_SIZE (i)); |
573aba85 | 2572 | num_objs = bytes / OBJECT_SIZE (i); |
4077bf7a | 2573 | entry = XCNEWVAR (struct page_entry, (sizeof (struct page_entry) |
2574 | - sizeof (long) | |
2575 | + BITMAP_SIZE (num_objs + 1))); | |
573aba85 | 2576 | entry->bytes = bytes; |
2577 | entry->page = offs; | |
2578 | entry->context_depth = 0; | |
2579 | offs += bytes; | |
2580 | entry->num_free_objects = 0; | |
2581 | entry->order = i; | |
2582 | ||
6ec1f4e0 | 2583 | for (j = 0; |
573aba85 | 2584 | j + HOST_BITS_PER_LONG <= num_objs + 1; |
2585 | j += HOST_BITS_PER_LONG) | |
2586 | entry->in_use_p[j / HOST_BITS_PER_LONG] = -1; | |
2587 | for (; j < num_objs + 1; j++) | |
6ec1f4e0 | 2588 | entry->in_use_p[j / HOST_BITS_PER_LONG] |
573aba85 | 2589 | |= 1L << (j % HOST_BITS_PER_LONG); |
2590 | ||
6ec1f4e0 | 2591 | for (pte = entry->page; |
2592 | pte < entry->page + entry->bytes; | |
573aba85 | 2593 | pte += G.pagesize) |
2594 | set_page_table_entry (pte, entry); | |
2595 | ||
2596 | if (G.page_tails[i] != NULL) | |
2597 | G.page_tails[i]->next = entry; | |
2598 | else | |
2599 | G.pages[i] = entry; | |
2600 | G.page_tails[i] = entry; | |
76e1b933 | 2601 | |
2602 | /* We start off by just adding all the new information to the | |
2603 | end of the varrays, later, we will move the new information | |
2604 | to the front of the varrays, as the PCH page tables are at | |
2605 | context 0. */ | |
2606 | push_by_depth (entry, 0); | |
573aba85 | 2607 | } |
2608 | ||
76e1b933 | 2609 | /* Now, we update the various data structures that speed page table |
2610 | handling. */ | |
2611 | count_new_page_tables = G.by_depth_in_use - count_old_page_tables; | |
2612 | ||
2613 | move_ptes_to_front (count_old_page_tables, count_new_page_tables); | |
2614 | ||
573aba85 | 2615 | /* Update the statistics. */ |
2616 | G.allocated = G.allocated_last_gc = offs - (char *)addr; | |
2617 | } |