Mercurial > hg > CbC > CbC_gcc
annotate gcc/ggc-page.c @ 158:494b0b89df80 default tip
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author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Mon, 25 May 2020 18:13:55 +0900 |
parents | 1830386684a0 |
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rev | line source |
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0 | 1 /* "Bag-of-pages" garbage collector for the GNU compiler. |
145 | 2 Copyright (C) 1999-2020 Free Software Foundation, Inc. |
0 | 3 |
4 This file is part of GCC. | |
5 | |
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 | |
8 Software Foundation; either version 3, or (at your option) any later | |
9 version. | |
10 | |
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. | |
15 | |
16 You should have received a copy of the GNU General Public License | |
17 along with GCC; see the file COPYING3. If not see | |
18 <http://www.gnu.org/licenses/>. */ | |
19 | |
20 #include "config.h" | |
21 #include "system.h" | |
22 #include "coretypes.h" | |
111 | 23 #include "backend.h" |
24 #include "alias.h" | |
0 | 25 #include "tree.h" |
26 #include "rtl.h" | |
111 | 27 #include "memmodel.h" |
0 | 28 #include "tm_p.h" |
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29 #include "diagnostic-core.h" |
0 | 30 #include "flags.h" |
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31 #include "ggc-internal.h" |
0 | 32 #include "timevar.h" |
111 | 33 #include "cgraph.h" |
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34 #include "cfgloop.h" |
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35 #include "plugin.h" |
0 | 36 |
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 | |
41 # define USING_MMAP | |
42 #endif | |
43 | |
44 #ifdef HAVE_MMAP_DEV_ZERO | |
45 # define USING_MMAP | |
46 #endif | |
47 | |
48 #ifndef USING_MMAP | |
49 #define USING_MALLOC_PAGE_GROUPS | |
50 #endif | |
51 | |
111 | 52 #if defined(HAVE_MADVISE) && HAVE_DECL_MADVISE && defined(MADV_DONTNEED) \ |
53 && defined(USING_MMAP) | |
54 # define USING_MADVISE | |
55 #endif | |
56 | |
0 | 57 /* Strategy: |
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 | |
72 in the current (highest-numbered) context may be collected. | |
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 | |
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. | |
91 4: Object marks as well. */ | |
92 #define GGC_DEBUG_LEVEL (0) | |
93 | |
94 /* A two-level tree is used to look up the page-entry for a given | |
95 pointer. Two chunks of the pointer's bits are extracted to index | |
96 the first and second levels of the tree, as follows: | |
97 | |
98 HOST_PAGE_SIZE_BITS | |
99 32 | | | |
100 msb +----------------+----+------+------+ lsb | |
101 | | | | |
102 PAGE_L1_BITS | | |
103 | | | |
104 PAGE_L2_BITS | |
105 | |
106 The bottommost HOST_PAGE_SIZE_BITS are ignored, since page-entry | |
107 pages are aligned on system page boundaries. The next most | |
108 significant PAGE_L2_BITS and PAGE_L1_BITS are the second and first | |
109 index values in the lookup table, respectively. | |
110 | |
111 For 32-bit architectures and the settings below, there are no | |
112 leftover bits. For architectures with wider pointers, the lookup | |
113 tree points to a list of pages, which must be scanned to find the | |
114 correct one. */ | |
115 | |
116 #define PAGE_L1_BITS (8) | |
117 #define PAGE_L2_BITS (32 - PAGE_L1_BITS - G.lg_pagesize) | |
111 | 118 #define PAGE_L1_SIZE ((uintptr_t) 1 << PAGE_L1_BITS) |
119 #define PAGE_L2_SIZE ((uintptr_t) 1 << PAGE_L2_BITS) | |
0 | 120 |
121 #define LOOKUP_L1(p) \ | |
111 | 122 (((uintptr_t) (p) >> (32 - PAGE_L1_BITS)) & ((1 << PAGE_L1_BITS) - 1)) |
0 | 123 |
124 #define LOOKUP_L2(p) \ | |
111 | 125 (((uintptr_t) (p) >> G.lg_pagesize) & ((1 << PAGE_L2_BITS) - 1)) |
0 | 126 |
127 /* The number of objects per allocation page, for objects on a page of | |
128 the indicated ORDER. */ | |
129 #define OBJECTS_PER_PAGE(ORDER) objects_per_page_table[ORDER] | |
130 | |
131 /* The number of objects in P. */ | |
132 #define OBJECTS_IN_PAGE(P) ((P)->bytes / OBJECT_SIZE ((P)->order)) | |
133 | |
134 /* The size of an object on a page of the indicated ORDER. */ | |
135 #define OBJECT_SIZE(ORDER) object_size_table[ORDER] | |
136 | |
137 /* For speed, we avoid doing a general integer divide to locate the | |
138 offset in the allocation bitmap, by precalculating numbers M, S | |
139 such that (O * M) >> S == O / Z (modulo 2^32), for any offset O | |
140 within the page which is evenly divisible by the object size Z. */ | |
141 #define DIV_MULT(ORDER) inverse_table[ORDER].mult | |
142 #define DIV_SHIFT(ORDER) inverse_table[ORDER].shift | |
143 #define OFFSET_TO_BIT(OFFSET, ORDER) \ | |
144 (((OFFSET) * DIV_MULT (ORDER)) >> DIV_SHIFT (ORDER)) | |
145 | |
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146 /* We use this structure to determine the alignment required for |
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147 allocations. For power-of-two sized allocations, that's not a |
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148 problem, but it does matter for odd-sized allocations. |
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149 We do not care about alignment for floating-point types. */ |
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150 |
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151 struct max_alignment { |
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152 char c; |
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153 union { |
111 | 154 int64_t i; |
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155 void *p; |
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156 } u; |
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157 }; |
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158 |
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159 /* The biggest alignment required. */ |
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160 |
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161 #define MAX_ALIGNMENT (offsetof (struct max_alignment, u)) |
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162 |
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163 |
0 | 164 /* The number of extra orders, not corresponding to power-of-two sized |
165 objects. */ | |
166 | |
167 #define NUM_EXTRA_ORDERS ARRAY_SIZE (extra_order_size_table) | |
168 | |
169 #define RTL_SIZE(NSLOTS) \ | |
170 (RTX_HDR_SIZE + (NSLOTS) * sizeof (rtunion)) | |
171 | |
172 #define TREE_EXP_SIZE(OPS) \ | |
173 (sizeof (struct tree_exp) + ((OPS) - 1) * sizeof (tree)) | |
174 | |
175 /* The Ith entry is the maximum size of an object to be stored in the | |
176 Ith extra order. Adding a new entry to this array is the *only* | |
177 thing you need to do to add a new special allocation size. */ | |
178 | |
179 static const size_t extra_order_size_table[] = { | |
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180 /* Extra orders for small non-power-of-two multiples of MAX_ALIGNMENT. |
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181 There are a lot of structures with these sizes and explicitly |
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182 listing them risks orders being dropped because they changed size. */ |
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183 MAX_ALIGNMENT * 3, |
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184 MAX_ALIGNMENT * 5, |
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185 MAX_ALIGNMENT * 6, |
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186 MAX_ALIGNMENT * 7, |
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187 MAX_ALIGNMENT * 9, |
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188 MAX_ALIGNMENT * 10, |
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189 MAX_ALIGNMENT * 11, |
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190 MAX_ALIGNMENT * 12, |
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191 MAX_ALIGNMENT * 13, |
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192 MAX_ALIGNMENT * 14, |
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193 MAX_ALIGNMENT * 15, |
0 | 194 sizeof (struct tree_decl_non_common), |
195 sizeof (struct tree_field_decl), | |
196 sizeof (struct tree_parm_decl), | |
197 sizeof (struct tree_var_decl), | |
111 | 198 sizeof (struct tree_type_non_common), |
0 | 199 sizeof (struct function), |
200 sizeof (struct basic_block_def), | |
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201 sizeof (struct cgraph_node), |
145 | 202 sizeof (class loop), |
0 | 203 }; |
204 | |
205 /* The total number of orders. */ | |
206 | |
207 #define NUM_ORDERS (HOST_BITS_PER_PTR + NUM_EXTRA_ORDERS) | |
208 | |
209 /* Compute the smallest nonnegative number which when added to X gives | |
210 a multiple of F. */ | |
211 | |
212 #define ROUND_UP_VALUE(x, f) ((f) - 1 - ((f) - 1 + (x)) % (f)) | |
213 | |
111 | 214 /* Round X to next multiple of the page size */ |
215 | |
216 #define PAGE_ALIGN(x) ROUND_UP ((x), G.pagesize) | |
0 | 217 |
218 /* The Ith entry is the number of objects on a page or order I. */ | |
219 | |
220 static unsigned objects_per_page_table[NUM_ORDERS]; | |
221 | |
222 /* The Ith entry is the size of an object on a page of order I. */ | |
223 | |
224 static size_t object_size_table[NUM_ORDERS]; | |
225 | |
226 /* The Ith entry is a pair of numbers (mult, shift) such that | |
227 ((k * mult) >> shift) mod 2^32 == (k / OBJECT_SIZE(I)) mod 2^32, | |
228 for all k evenly divisible by OBJECT_SIZE(I). */ | |
229 | |
230 static struct | |
231 { | |
232 size_t mult; | |
233 unsigned int shift; | |
234 } | |
235 inverse_table[NUM_ORDERS]; | |
236 | |
237 /* A page_entry records the status of an allocation page. This | |
238 structure is dynamically sized to fit the bitmap in_use_p. */ | |
111 | 239 struct page_entry |
0 | 240 { |
241 /* The next page-entry with objects of the same size, or NULL if | |
242 this is the last page-entry. */ | |
243 struct page_entry *next; | |
244 | |
245 /* The previous page-entry with objects of the same size, or NULL if | |
246 this is the first page-entry. The PREV pointer exists solely to | |
247 keep the cost of ggc_free manageable. */ | |
248 struct page_entry *prev; | |
249 | |
250 /* The number of bytes allocated. (This will always be a multiple | |
251 of the host system page size.) */ | |
252 size_t bytes; | |
253 | |
254 /* The address at which the memory is allocated. */ | |
255 char *page; | |
256 | |
257 #ifdef USING_MALLOC_PAGE_GROUPS | |
258 /* Back pointer to the page group this page came from. */ | |
259 struct page_group *group; | |
260 #endif | |
261 | |
262 /* This is the index in the by_depth varray where this page table | |
263 can be found. */ | |
264 unsigned long index_by_depth; | |
265 | |
266 /* Context depth of this page. */ | |
267 unsigned short context_depth; | |
268 | |
269 /* The number of free objects remaining on this page. */ | |
270 unsigned short num_free_objects; | |
271 | |
272 /* A likely candidate for the bit position of a free object for the | |
273 next allocation from this page. */ | |
274 unsigned short next_bit_hint; | |
275 | |
276 /* The lg of size of objects allocated from this page. */ | |
277 unsigned char order; | |
278 | |
111 | 279 /* Discarded page? */ |
280 bool discarded; | |
281 | |
0 | 282 /* A bit vector indicating whether or not objects are in use. The |
283 Nth bit is one if the Nth object on this page is allocated. This | |
284 array is dynamically sized. */ | |
285 unsigned long in_use_p[1]; | |
111 | 286 }; |
0 | 287 |
288 #ifdef USING_MALLOC_PAGE_GROUPS | |
289 /* A page_group describes a large allocation from malloc, from which | |
290 we parcel out aligned pages. */ | |
111 | 291 struct page_group |
0 | 292 { |
293 /* A linked list of all extant page groups. */ | |
294 struct page_group *next; | |
295 | |
296 /* The address we received from malloc. */ | |
297 char *allocation; | |
298 | |
299 /* The size of the block. */ | |
300 size_t alloc_size; | |
301 | |
302 /* A bitmask of pages in use. */ | |
303 unsigned int in_use; | |
111 | 304 }; |
0 | 305 #endif |
306 | |
307 #if HOST_BITS_PER_PTR <= 32 | |
308 | |
309 /* On 32-bit hosts, we use a two level page table, as pictured above. */ | |
310 typedef page_entry **page_table[PAGE_L1_SIZE]; | |
311 | |
312 #else | |
313 | |
314 /* On 64-bit hosts, we use the same two level page tables plus a linked | |
315 list that disambiguates the top 32-bits. There will almost always be | |
316 exactly one entry in the list. */ | |
317 typedef struct page_table_chain | |
318 { | |
319 struct page_table_chain *next; | |
320 size_t high_bits; | |
321 page_entry **table[PAGE_L1_SIZE]; | |
322 } *page_table; | |
323 | |
324 #endif | |
325 | |
111 | 326 class finalizer |
327 { | |
328 public: | |
329 finalizer (void *addr, void (*f)(void *)) : m_addr (addr), m_function (f) {} | |
330 | |
331 void *addr () const { return m_addr; } | |
332 | |
333 void call () const { m_function (m_addr); } | |
334 | |
335 private: | |
336 void *m_addr; | |
337 void (*m_function)(void *); | |
338 }; | |
339 | |
340 class vec_finalizer | |
341 { | |
342 public: | |
343 vec_finalizer (uintptr_t addr, void (*f)(void *), size_t s, size_t n) : | |
344 m_addr (addr), m_function (f), m_object_size (s), m_n_objects (n) {} | |
345 | |
346 void call () const | |
347 { | |
348 for (size_t i = 0; i < m_n_objects; i++) | |
349 m_function (reinterpret_cast<void *> (m_addr + (i * m_object_size))); | |
350 } | |
351 | |
352 void *addr () const { return reinterpret_cast<void *> (m_addr); } | |
353 | |
354 private: | |
355 uintptr_t m_addr; | |
356 void (*m_function)(void *); | |
357 size_t m_object_size; | |
358 size_t m_n_objects; | |
359 }; | |
360 | |
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361 #ifdef ENABLE_GC_ALWAYS_COLLECT |
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362 /* List of free objects to be verified as actually free on the |
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363 next collection. */ |
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364 struct free_object |
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365 { |
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366 void *object; |
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367 struct free_object *next; |
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368 }; |
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369 #endif |
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370 |
0 | 371 /* The rest of the global variables. */ |
111 | 372 static struct ggc_globals |
0 | 373 { |
374 /* The Nth element in this array is a page with objects of size 2^N. | |
375 If there are any pages with free objects, they will be at the | |
376 head of the list. NULL if there are no page-entries for this | |
377 object size. */ | |
378 page_entry *pages[NUM_ORDERS]; | |
379 | |
380 /* The Nth element in this array is the last page with objects of | |
381 size 2^N. NULL if there are no page-entries for this object | |
382 size. */ | |
383 page_entry *page_tails[NUM_ORDERS]; | |
384 | |
385 /* Lookup table for associating allocation pages with object addresses. */ | |
386 page_table lookup; | |
387 | |
388 /* The system's page size. */ | |
389 size_t pagesize; | |
390 size_t lg_pagesize; | |
391 | |
392 /* Bytes currently allocated. */ | |
393 size_t allocated; | |
394 | |
395 /* Bytes currently allocated at the end of the last collection. */ | |
396 size_t allocated_last_gc; | |
397 | |
398 /* Total amount of memory mapped. */ | |
399 size_t bytes_mapped; | |
400 | |
401 /* Bit N set if any allocations have been done at context depth N. */ | |
402 unsigned long context_depth_allocations; | |
403 | |
404 /* Bit N set if any collections have been done at context depth N. */ | |
405 unsigned long context_depth_collections; | |
406 | |
407 /* The current depth in the context stack. */ | |
408 unsigned short context_depth; | |
409 | |
410 /* A file descriptor open to /dev/zero for reading. */ | |
411 #if defined (HAVE_MMAP_DEV_ZERO) | |
412 int dev_zero_fd; | |
413 #endif | |
414 | |
415 /* A cache of free system pages. */ | |
416 page_entry *free_pages; | |
417 | |
418 #ifdef USING_MALLOC_PAGE_GROUPS | |
419 page_group *page_groups; | |
420 #endif | |
421 | |
422 /* The file descriptor for debugging output. */ | |
423 FILE *debug_file; | |
424 | |
425 /* Current number of elements in use in depth below. */ | |
426 unsigned int depth_in_use; | |
427 | |
428 /* Maximum number of elements that can be used before resizing. */ | |
429 unsigned int depth_max; | |
430 | |
431 /* Each element of this array is an index in by_depth where the given | |
432 depth starts. This structure is indexed by that given depth we | |
433 are interested in. */ | |
434 unsigned int *depth; | |
435 | |
436 /* Current number of elements in use in by_depth below. */ | |
437 unsigned int by_depth_in_use; | |
438 | |
439 /* Maximum number of elements that can be used before resizing. */ | |
440 unsigned int by_depth_max; | |
441 | |
442 /* Each element of this array is a pointer to a page_entry, all | |
443 page_entries can be found in here by increasing depth. | |
444 index_by_depth in the page_entry is the index into this data | |
445 structure where that page_entry can be found. This is used to | |
446 speed up finding all page_entries at a particular depth. */ | |
447 page_entry **by_depth; | |
448 | |
449 /* Each element is a pointer to the saved in_use_p bits, if any, | |
450 zero otherwise. We allocate them all together, to enable a | |
451 better runtime data access pattern. */ | |
452 unsigned long **save_in_use; | |
453 | |
111 | 454 /* Finalizers for single objects. The first index is collection_depth. */ |
455 vec<vec<finalizer> > finalizers; | |
456 | |
457 /* Finalizers for vectors of objects. */ | |
458 vec<vec<vec_finalizer> > vec_finalizers; | |
459 | |
0 | 460 #ifdef ENABLE_GC_ALWAYS_COLLECT |
461 /* List of free objects to be verified as actually free on the | |
462 next collection. */ | |
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463 struct free_object *free_object_list; |
0 | 464 #endif |
465 | |
466 struct | |
467 { | |
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468 /* Total GC-allocated memory. */ |
0 | 469 unsigned long long total_allocated; |
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470 /* Total overhead for GC-allocated memory. */ |
0 | 471 unsigned long long total_overhead; |
472 | |
473 /* Total allocations and overhead for sizes less than 32, 64 and 128. | |
474 These sizes are interesting because they are typical cache line | |
475 sizes. */ | |
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476 |
0 | 477 unsigned long long total_allocated_under32; |
478 unsigned long long total_overhead_under32; | |
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479 |
0 | 480 unsigned long long total_allocated_under64; |
481 unsigned long long total_overhead_under64; | |
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482 |
0 | 483 unsigned long long total_allocated_under128; |
484 unsigned long long total_overhead_under128; | |
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485 |
0 | 486 /* The allocations for each of the allocation orders. */ |
487 unsigned long long total_allocated_per_order[NUM_ORDERS]; | |
488 | |
489 /* The overhead for each of the allocation orders. */ | |
490 unsigned long long total_overhead_per_order[NUM_ORDERS]; | |
491 } stats; | |
492 } G; | |
493 | |
111 | 494 /* True if a gc is currently taking place. */ |
495 | |
496 static bool in_gc = false; | |
497 | |
0 | 498 /* The size in bytes required to maintain a bitmap for the objects |
499 on a page-entry. */ | |
500 #define BITMAP_SIZE(Num_objects) \ | |
111 | 501 (CEIL ((Num_objects), HOST_BITS_PER_LONG) * sizeof (long)) |
0 | 502 |
503 /* Allocate pages in chunks of this size, to throttle calls to memory | |
504 allocation routines. The first page is used, the rest go onto the | |
505 free list. This cannot be larger than HOST_BITS_PER_INT for the | |
506 in_use bitmask for page_group. Hosts that need a different value | |
507 can override this by defining GGC_QUIRE_SIZE explicitly. */ | |
508 #ifndef GGC_QUIRE_SIZE | |
509 # ifdef USING_MMAP | |
111 | 510 # define GGC_QUIRE_SIZE 512 /* 2MB for 4K pages */ |
0 | 511 # else |
512 # define GGC_QUIRE_SIZE 16 | |
513 # endif | |
514 #endif | |
515 | |
516 /* Initial guess as to how many page table entries we might need. */ | |
517 #define INITIAL_PTE_COUNT 128 | |
518 | |
519 static page_entry *lookup_page_table_entry (const void *); | |
520 static void set_page_table_entry (void *, page_entry *); | |
521 #ifdef USING_MMAP | |
111 | 522 static char *alloc_anon (char *, size_t, bool check); |
0 | 523 #endif |
524 #ifdef USING_MALLOC_PAGE_GROUPS | |
525 static size_t page_group_index (char *, char *); | |
526 static void set_page_group_in_use (page_group *, char *); | |
527 static void clear_page_group_in_use (page_group *, char *); | |
528 #endif | |
529 static struct page_entry * alloc_page (unsigned); | |
530 static void free_page (struct page_entry *); | |
531 static void clear_marks (void); | |
532 static void sweep_pages (void); | |
533 static void ggc_recalculate_in_use_p (page_entry *); | |
534 static void compute_inverse (unsigned); | |
535 static inline void adjust_depth (void); | |
536 static void move_ptes_to_front (int, int); | |
537 | |
538 void debug_print_page_list (int); | |
539 static void push_depth (unsigned int); | |
540 static void push_by_depth (page_entry *, unsigned long *); | |
541 | |
542 /* Push an entry onto G.depth. */ | |
543 | |
544 inline static void | |
545 push_depth (unsigned int i) | |
546 { | |
547 if (G.depth_in_use >= G.depth_max) | |
548 { | |
549 G.depth_max *= 2; | |
550 G.depth = XRESIZEVEC (unsigned int, G.depth, G.depth_max); | |
551 } | |
552 G.depth[G.depth_in_use++] = i; | |
553 } | |
554 | |
555 /* Push an entry onto G.by_depth and G.save_in_use. */ | |
556 | |
557 inline static void | |
558 push_by_depth (page_entry *p, unsigned long *s) | |
559 { | |
560 if (G.by_depth_in_use >= G.by_depth_max) | |
561 { | |
562 G.by_depth_max *= 2; | |
563 G.by_depth = XRESIZEVEC (page_entry *, G.by_depth, G.by_depth_max); | |
564 G.save_in_use = XRESIZEVEC (unsigned long *, G.save_in_use, | |
565 G.by_depth_max); | |
566 } | |
567 G.by_depth[G.by_depth_in_use] = p; | |
568 G.save_in_use[G.by_depth_in_use++] = s; | |
569 } | |
570 | |
571 #if (GCC_VERSION < 3001) | |
572 #define prefetch(X) ((void) X) | |
573 #else | |
574 #define prefetch(X) __builtin_prefetch (X) | |
575 #endif | |
576 | |
577 #define save_in_use_p_i(__i) \ | |
578 (G.save_in_use[__i]) | |
579 #define save_in_use_p(__p) \ | |
580 (save_in_use_p_i (__p->index_by_depth)) | |
581 | |
111 | 582 /* Traverse the page table and find the entry for a page. |
583 If the object wasn't allocated in GC return NULL. */ | |
584 | |
585 static inline page_entry * | |
586 safe_lookup_page_table_entry (const void *p) | |
0 | 587 { |
588 page_entry ***base; | |
589 size_t L1, L2; | |
590 | |
591 #if HOST_BITS_PER_PTR <= 32 | |
592 base = &G.lookup[0]; | |
593 #else | |
594 page_table table = G.lookup; | |
111 | 595 uintptr_t high_bits = (uintptr_t) p & ~ (uintptr_t) 0xffffffff; |
0 | 596 while (1) |
597 { | |
598 if (table == NULL) | |
111 | 599 return NULL; |
0 | 600 if (table->high_bits == high_bits) |
601 break; | |
602 table = table->next; | |
603 } | |
604 base = &table->table[0]; | |
605 #endif | |
606 | |
607 /* Extract the level 1 and 2 indices. */ | |
608 L1 = LOOKUP_L1 (p); | |
609 L2 = LOOKUP_L2 (p); | |
111 | 610 if (! base[L1]) |
611 return NULL; | |
612 | |
613 return base[L1][L2]; | |
0 | 614 } |
615 | |
616 /* Traverse the page table and find the entry for a page. | |
617 Die (probably) if the object wasn't allocated via GC. */ | |
618 | |
619 static inline page_entry * | |
620 lookup_page_table_entry (const void *p) | |
621 { | |
622 page_entry ***base; | |
623 size_t L1, L2; | |
624 | |
625 #if HOST_BITS_PER_PTR <= 32 | |
626 base = &G.lookup[0]; | |
627 #else | |
628 page_table table = G.lookup; | |
111 | 629 uintptr_t high_bits = (uintptr_t) p & ~ (uintptr_t) 0xffffffff; |
0 | 630 while (table->high_bits != high_bits) |
631 table = table->next; | |
632 base = &table->table[0]; | |
633 #endif | |
634 | |
635 /* Extract the level 1 and 2 indices. */ | |
636 L1 = LOOKUP_L1 (p); | |
637 L2 = LOOKUP_L2 (p); | |
638 | |
639 return base[L1][L2]; | |
640 } | |
641 | |
642 /* Set the page table entry for a page. */ | |
643 | |
644 static void | |
645 set_page_table_entry (void *p, page_entry *entry) | |
646 { | |
647 page_entry ***base; | |
648 size_t L1, L2; | |
649 | |
650 #if HOST_BITS_PER_PTR <= 32 | |
651 base = &G.lookup[0]; | |
652 #else | |
653 page_table table; | |
111 | 654 uintptr_t high_bits = (uintptr_t) p & ~ (uintptr_t) 0xffffffff; |
0 | 655 for (table = G.lookup; table; table = table->next) |
656 if (table->high_bits == high_bits) | |
657 goto found; | |
658 | |
659 /* Not found -- allocate a new table. */ | |
660 table = XCNEW (struct page_table_chain); | |
661 table->next = G.lookup; | |
662 table->high_bits = high_bits; | |
663 G.lookup = table; | |
664 found: | |
665 base = &table->table[0]; | |
666 #endif | |
667 | |
668 /* Extract the level 1 and 2 indices. */ | |
669 L1 = LOOKUP_L1 (p); | |
670 L2 = LOOKUP_L2 (p); | |
671 | |
672 if (base[L1] == NULL) | |
673 base[L1] = XCNEWVEC (page_entry *, PAGE_L2_SIZE); | |
674 | |
675 base[L1][L2] = entry; | |
676 } | |
677 | |
678 /* Prints the page-entry for object size ORDER, for debugging. */ | |
679 | |
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680 DEBUG_FUNCTION void |
0 | 681 debug_print_page_list (int order) |
682 { | |
683 page_entry *p; | |
684 printf ("Head=%p, Tail=%p:\n", (void *) G.pages[order], | |
685 (void *) G.page_tails[order]); | |
686 p = G.pages[order]; | |
687 while (p != NULL) | |
688 { | |
689 printf ("%p(%1d|%3d) -> ", (void *) p, p->context_depth, | |
690 p->num_free_objects); | |
691 p = p->next; | |
692 } | |
693 printf ("NULL\n"); | |
694 fflush (stdout); | |
695 } | |
696 | |
697 #ifdef USING_MMAP | |
698 /* Allocate SIZE bytes of anonymous memory, preferably near PREF, | |
699 (if non-null). The ifdef structure here is intended to cause a | |
700 compile error unless exactly one of the HAVE_* is defined. */ | |
701 | |
702 static inline char * | |
111 | 703 alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size, bool check) |
0 | 704 { |
705 #ifdef HAVE_MMAP_ANON | |
706 char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, | |
707 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
708 #endif | |
709 #ifdef HAVE_MMAP_DEV_ZERO | |
710 char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, | |
711 MAP_PRIVATE, G.dev_zero_fd, 0); | |
712 #endif | |
713 | |
714 if (page == (char *) MAP_FAILED) | |
715 { | |
111 | 716 if (!check) |
717 return NULL; | |
0 | 718 perror ("virtual memory exhausted"); |
719 exit (FATAL_EXIT_CODE); | |
720 } | |
721 | |
722 /* Remember that we allocated this memory. */ | |
723 G.bytes_mapped += size; | |
724 | |
725 /* Pretend we don't have access to the allocated pages. We'll enable | |
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726 access to smaller pieces of the area in ggc_internal_alloc. Discard the |
0 | 727 handle to avoid handle leak. */ |
728 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (page, size)); | |
729 | |
730 return page; | |
731 } | |
732 #endif | |
733 #ifdef USING_MALLOC_PAGE_GROUPS | |
734 /* Compute the index for this page into the page group. */ | |
735 | |
736 static inline size_t | |
737 page_group_index (char *allocation, char *page) | |
738 { | |
739 return (size_t) (page - allocation) >> G.lg_pagesize; | |
740 } | |
741 | |
742 /* Set and clear the in_use bit for this page in the page group. */ | |
743 | |
744 static inline void | |
745 set_page_group_in_use (page_group *group, char *page) | |
746 { | |
747 group->in_use |= 1 << page_group_index (group->allocation, page); | |
748 } | |
749 | |
750 static inline void | |
751 clear_page_group_in_use (page_group *group, char *page) | |
752 { | |
753 group->in_use &= ~(1 << page_group_index (group->allocation, page)); | |
754 } | |
755 #endif | |
756 | |
757 /* Allocate a new page for allocating objects of size 2^ORDER, | |
758 and return an entry for it. The entry is not added to the | |
759 appropriate page_table list. */ | |
760 | |
761 static inline struct page_entry * | |
762 alloc_page (unsigned order) | |
763 { | |
764 struct page_entry *entry, *p, **pp; | |
765 char *page; | |
766 size_t num_objects; | |
767 size_t bitmap_size; | |
768 size_t page_entry_size; | |
769 size_t entry_size; | |
770 #ifdef USING_MALLOC_PAGE_GROUPS | |
771 page_group *group; | |
772 #endif | |
773 | |
774 num_objects = OBJECTS_PER_PAGE (order); | |
775 bitmap_size = BITMAP_SIZE (num_objects + 1); | |
776 page_entry_size = sizeof (page_entry) - sizeof (long) + bitmap_size; | |
777 entry_size = num_objects * OBJECT_SIZE (order); | |
778 if (entry_size < G.pagesize) | |
779 entry_size = G.pagesize; | |
111 | 780 entry_size = PAGE_ALIGN (entry_size); |
0 | 781 |
782 entry = NULL; | |
783 page = NULL; | |
784 | |
785 /* Check the list of free pages for one we can use. */ | |
786 for (pp = &G.free_pages, p = *pp; p; pp = &p->next, p = *pp) | |
787 if (p->bytes == entry_size) | |
788 break; | |
789 | |
790 if (p != NULL) | |
791 { | |
111 | 792 if (p->discarded) |
793 G.bytes_mapped += p->bytes; | |
794 p->discarded = false; | |
795 | |
0 | 796 /* Recycle the allocated memory from this page ... */ |
797 *pp = p->next; | |
798 page = p->page; | |
799 | |
800 #ifdef USING_MALLOC_PAGE_GROUPS | |
801 group = p->group; | |
802 #endif | |
803 | |
804 /* ... and, if possible, the page entry itself. */ | |
805 if (p->order == order) | |
806 { | |
807 entry = p; | |
808 memset (entry, 0, page_entry_size); | |
809 } | |
810 else | |
811 free (p); | |
812 } | |
813 #ifdef USING_MMAP | |
814 else if (entry_size == G.pagesize) | |
815 { | |
816 /* We want just one page. Allocate a bunch of them and put the | |
817 extras on the freelist. (Can only do this optimization with | |
818 mmap for backing store.) */ | |
819 struct page_entry *e, *f = G.free_pages; | |
111 | 820 int i, entries = GGC_QUIRE_SIZE; |
821 | |
822 page = alloc_anon (NULL, G.pagesize * GGC_QUIRE_SIZE, false); | |
823 if (page == NULL) | |
824 { | |
825 page = alloc_anon (NULL, G.pagesize, true); | |
826 entries = 1; | |
827 } | |
0 | 828 |
829 /* This loop counts down so that the chain will be in ascending | |
830 memory order. */ | |
111 | 831 for (i = entries - 1; i >= 1; i--) |
0 | 832 { |
833 e = XCNEWVAR (struct page_entry, page_entry_size); | |
834 e->order = order; | |
835 e->bytes = G.pagesize; | |
836 e->page = page + (i << G.lg_pagesize); | |
837 e->next = f; | |
838 f = e; | |
839 } | |
840 | |
841 G.free_pages = f; | |
842 } | |
843 else | |
111 | 844 page = alloc_anon (NULL, entry_size, true); |
0 | 845 #endif |
846 #ifdef USING_MALLOC_PAGE_GROUPS | |
847 else | |
848 { | |
849 /* Allocate a large block of memory and serve out the aligned | |
850 pages therein. This results in much less memory wastage | |
851 than the traditional implementation of valloc. */ | |
852 | |
853 char *allocation, *a, *enda; | |
854 size_t alloc_size, head_slop, tail_slop; | |
855 int multiple_pages = (entry_size == G.pagesize); | |
856 | |
857 if (multiple_pages) | |
858 alloc_size = GGC_QUIRE_SIZE * G.pagesize; | |
859 else | |
860 alloc_size = entry_size + G.pagesize - 1; | |
861 allocation = XNEWVEC (char, alloc_size); | |
862 | |
111 | 863 page = (char *) (((uintptr_t) allocation + G.pagesize - 1) & -G.pagesize); |
0 | 864 head_slop = page - allocation; |
865 if (multiple_pages) | |
866 tail_slop = ((size_t) allocation + alloc_size) & (G.pagesize - 1); | |
867 else | |
868 tail_slop = alloc_size - entry_size - head_slop; | |
869 enda = allocation + alloc_size - tail_slop; | |
870 | |
871 /* We allocated N pages, which are likely not aligned, leaving | |
872 us with N-1 usable pages. We plan to place the page_group | |
873 structure somewhere in the slop. */ | |
874 if (head_slop >= sizeof (page_group)) | |
875 group = (page_group *)page - 1; | |
876 else | |
877 { | |
878 /* We magically got an aligned allocation. Too bad, we have | |
879 to waste a page anyway. */ | |
880 if (tail_slop == 0) | |
881 { | |
882 enda -= G.pagesize; | |
883 tail_slop += G.pagesize; | |
884 } | |
885 gcc_assert (tail_slop >= sizeof (page_group)); | |
886 group = (page_group *)enda; | |
887 tail_slop -= sizeof (page_group); | |
888 } | |
889 | |
890 /* Remember that we allocated this memory. */ | |
891 group->next = G.page_groups; | |
892 group->allocation = allocation; | |
893 group->alloc_size = alloc_size; | |
894 group->in_use = 0; | |
895 G.page_groups = group; | |
896 G.bytes_mapped += alloc_size; | |
897 | |
898 /* If we allocated multiple pages, put the rest on the free list. */ | |
899 if (multiple_pages) | |
900 { | |
901 struct page_entry *e, *f = G.free_pages; | |
902 for (a = enda - G.pagesize; a != page; a -= G.pagesize) | |
903 { | |
904 e = XCNEWVAR (struct page_entry, page_entry_size); | |
905 e->order = order; | |
906 e->bytes = G.pagesize; | |
907 e->page = a; | |
908 e->group = group; | |
909 e->next = f; | |
910 f = e; | |
911 } | |
912 G.free_pages = f; | |
913 } | |
914 } | |
915 #endif | |
916 | |
917 if (entry == NULL) | |
918 entry = XCNEWVAR (struct page_entry, page_entry_size); | |
919 | |
920 entry->bytes = entry_size; | |
921 entry->page = page; | |
922 entry->context_depth = G.context_depth; | |
923 entry->order = order; | |
924 entry->num_free_objects = num_objects; | |
925 entry->next_bit_hint = 1; | |
926 | |
927 G.context_depth_allocations |= (unsigned long)1 << G.context_depth; | |
928 | |
929 #ifdef USING_MALLOC_PAGE_GROUPS | |
930 entry->group = group; | |
931 set_page_group_in_use (group, page); | |
932 #endif | |
933 | |
934 /* Set the one-past-the-end in-use bit. This acts as a sentry as we | |
935 increment the hint. */ | |
936 entry->in_use_p[num_objects / HOST_BITS_PER_LONG] | |
937 = (unsigned long) 1 << (num_objects % HOST_BITS_PER_LONG); | |
938 | |
939 set_page_table_entry (page, entry); | |
940 | |
941 if (GGC_DEBUG_LEVEL >= 2) | |
942 fprintf (G.debug_file, | |
943 "Allocating page at %p, object size=%lu, data %p-%p\n", | |
145 | 944 (void *) entry, (unsigned long) OBJECT_SIZE (order), |
945 (void *) page, (void *) (page + entry_size - 1)); | |
0 | 946 |
947 return entry; | |
948 } | |
949 | |
950 /* Adjust the size of G.depth so that no index greater than the one | |
951 used by the top of the G.by_depth is used. */ | |
952 | |
953 static inline void | |
954 adjust_depth (void) | |
955 { | |
956 page_entry *top; | |
957 | |
958 if (G.by_depth_in_use) | |
959 { | |
960 top = G.by_depth[G.by_depth_in_use-1]; | |
961 | |
962 /* Peel back indices in depth that index into by_depth, so that | |
963 as new elements are added to by_depth, we note the indices | |
964 of those elements, if they are for new context depths. */ | |
965 while (G.depth_in_use > (size_t)top->context_depth+1) | |
966 --G.depth_in_use; | |
967 } | |
968 } | |
969 | |
970 /* For a page that is no longer needed, put it on the free page list. */ | |
971 | |
972 static void | |
973 free_page (page_entry *entry) | |
974 { | |
975 if (GGC_DEBUG_LEVEL >= 2) | |
976 fprintf (G.debug_file, | |
977 "Deallocating page at %p, data %p-%p\n", (void *) entry, | |
145 | 978 (void *) entry->page, (void *) (entry->page + entry->bytes - 1)); |
0 | 979 |
980 /* Mark the page as inaccessible. Discard the handle to avoid handle | |
981 leak. */ | |
982 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (entry->page, entry->bytes)); | |
983 | |
984 set_page_table_entry (entry->page, NULL); | |
985 | |
986 #ifdef USING_MALLOC_PAGE_GROUPS | |
987 clear_page_group_in_use (entry->group, entry->page); | |
988 #endif | |
989 | |
990 if (G.by_depth_in_use > 1) | |
991 { | |
992 page_entry *top = G.by_depth[G.by_depth_in_use-1]; | |
993 int i = entry->index_by_depth; | |
994 | |
995 /* We cannot free a page from a context deeper than the current | |
996 one. */ | |
997 gcc_assert (entry->context_depth == top->context_depth); | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
998 |
0 | 999 /* Put top element into freed slot. */ |
1000 G.by_depth[i] = top; | |
1001 G.save_in_use[i] = G.save_in_use[G.by_depth_in_use-1]; | |
1002 top->index_by_depth = i; | |
1003 } | |
1004 --G.by_depth_in_use; | |
1005 | |
1006 adjust_depth (); | |
1007 | |
1008 entry->next = G.free_pages; | |
1009 G.free_pages = entry; | |
1010 } | |
1011 | |
1012 /* Release the free page cache to the system. */ | |
1013 | |
1014 static void | |
1015 release_pages (void) | |
1016 { | |
145 | 1017 size_t n1 = 0; |
1018 size_t n2 = 0; | |
111 | 1019 #ifdef USING_MADVISE |
1020 page_entry *p, *start_p; | |
1021 char *start; | |
1022 size_t len; | |
1023 size_t mapped_len; | |
1024 page_entry *next, *prev, *newprev; | |
1025 size_t free_unit = (GGC_QUIRE_SIZE/2) * G.pagesize; | |
1026 | |
1027 /* First free larger continuous areas to the OS. | |
1028 This allows other allocators to grab these areas if needed. | |
1029 This is only done on larger chunks to avoid fragmentation. | |
1030 This does not always work because the free_pages list is only | |
1031 approximately sorted. */ | |
1032 | |
1033 p = G.free_pages; | |
1034 prev = NULL; | |
1035 while (p) | |
1036 { | |
1037 start = p->page; | |
1038 start_p = p; | |
1039 len = 0; | |
1040 mapped_len = 0; | |
1041 newprev = prev; | |
1042 while (p && p->page == start + len) | |
1043 { | |
1044 len += p->bytes; | |
1045 if (!p->discarded) | |
1046 mapped_len += p->bytes; | |
1047 newprev = p; | |
1048 p = p->next; | |
1049 } | |
1050 if (len >= free_unit) | |
1051 { | |
1052 while (start_p != p) | |
1053 { | |
1054 next = start_p->next; | |
1055 free (start_p); | |
1056 start_p = next; | |
1057 } | |
1058 munmap (start, len); | |
1059 if (prev) | |
1060 prev->next = p; | |
1061 else | |
1062 G.free_pages = p; | |
1063 G.bytes_mapped -= mapped_len; | |
145 | 1064 n1 += len; |
111 | 1065 continue; |
1066 } | |
1067 prev = newprev; | |
1068 } | |
1069 | |
1070 /* Now give back the fragmented pages to the OS, but keep the address | |
1071 space to reuse it next time. */ | |
1072 | |
1073 for (p = G.free_pages; p; ) | |
1074 { | |
1075 if (p->discarded) | |
1076 { | |
1077 p = p->next; | |
1078 continue; | |
1079 } | |
1080 start = p->page; | |
1081 len = p->bytes; | |
1082 start_p = p; | |
1083 p = p->next; | |
1084 while (p && p->page == start + len) | |
1085 { | |
1086 len += p->bytes; | |
1087 p = p->next; | |
1088 } | |
1089 /* Give the page back to the kernel, but don't free the mapping. | |
1090 This avoids fragmentation in the virtual memory map of the | |
1091 process. Next time we can reuse it by just touching it. */ | |
1092 madvise (start, len, MADV_DONTNEED); | |
1093 /* Don't count those pages as mapped to not touch the garbage collector | |
1094 unnecessarily. */ | |
1095 G.bytes_mapped -= len; | |
145 | 1096 n2 += len; |
111 | 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) | |
0 | 1105 page_entry *p, *next; |
1106 char *start; | |
1107 size_t len; | |
1108 | |
1109 /* Gather up adjacent pages so they are unmapped together. */ | |
1110 p = G.free_pages; | |
1111 | |
1112 while (p) | |
1113 { | |
1114 start = p->page; | |
1115 next = p->next; | |
1116 len = p->bytes; | |
1117 free (p); | |
1118 p = next; | |
1119 | |
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); | |
145 | 1129 n1 += len; |
0 | 1130 G.bytes_mapped -= len; |
1131 } | |
1132 | |
1133 G.free_pages = NULL; | |
1134 #endif | |
1135 #ifdef USING_MALLOC_PAGE_GROUPS | |
1136 page_entry **pp, *p; | |
1137 page_group **gp, *g; | |
1138 | |
1139 /* Remove all pages from free page groups from the list. */ | |
1140 pp = &G.free_pages; | |
1141 while ((p = *pp) != NULL) | |
1142 if (p->group->in_use == 0) | |
1143 { | |
1144 *pp = p->next; | |
1145 free (p); | |
1146 } | |
1147 else | |
1148 pp = &p->next; | |
1149 | |
1150 /* Remove all free page groups, and release the storage. */ | |
1151 gp = &G.page_groups; | |
1152 while ((g = *gp) != NULL) | |
1153 if (g->in_use == 0) | |
1154 { | |
1155 *gp = g->next; | |
1156 G.bytes_mapped -= g->alloc_size; | |
145 | 1157 n1 += g->alloc_size; |
0 | 1158 free (g->allocation); |
1159 } | |
1160 else | |
1161 gp = &g->next; | |
1162 #endif | |
145 | 1163 if (!quiet_flag && (n1 || n2)) |
1164 { | |
1165 fprintf (stderr, " {GC"); | |
1166 if (n1) | |
1167 fprintf (stderr, " released %luk", (unsigned long)(n1 / 1024)); | |
1168 if (n2) | |
1169 fprintf (stderr, " madv_dontneed %luk", (unsigned long)(n2 / 1024)); | |
1170 fprintf (stderr, "}"); | |
1171 } | |
0 | 1172 } |
1173 | |
1174 /* This table provides a fast way to determine ceil(log_2(size)) for | |
1175 allocation requests. The minimum allocation size is eight bytes. */ | |
1176 #define NUM_SIZE_LOOKUP 512 | |
1177 static unsigned char size_lookup[NUM_SIZE_LOOKUP] = | |
1178 { | |
1179 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, | |
1180 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, | |
1181 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
1182 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
1183 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
1184 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
1185 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
1186 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
1187 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1188 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1189 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1190 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1191 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1192 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1193 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1194 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
1195 8, 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, | |
1199 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1200 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1201 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1202 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1203 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1204 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1205 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1206 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1207 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1208 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1209 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
1210 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 | |
1211 }; | |
1212 | |
111 | 1213 /* For a given size of memory requested for allocation, return the |
1214 actual size that is going to be allocated, as well as the size | |
1215 order. */ | |
1216 | |
1217 static void | |
1218 ggc_round_alloc_size_1 (size_t requested_size, | |
1219 size_t *size_order, | |
1220 size_t *alloced_size) | |
0 | 1221 { |
111 | 1222 size_t order, object_size; |
1223 | |
1224 if (requested_size < NUM_SIZE_LOOKUP) | |
1225 { | |
1226 order = size_lookup[requested_size]; | |
1227 object_size = OBJECT_SIZE (order); | |
1228 } | |
1229 else | |
1230 { | |
1231 order = 10; | |
1232 while (requested_size > (object_size = OBJECT_SIZE (order))) | |
1233 order++; | |
1234 } | |
1235 | |
1236 if (size_order) | |
1237 *size_order = order; | |
1238 if (alloced_size) | |
1239 *alloced_size = object_size; | |
1240 } | |
1241 | |
1242 /* For a given size of memory requested for allocation, return the | |
1243 actual size that is going to be allocated. */ | |
1244 | |
1245 size_t | |
1246 ggc_round_alloc_size (size_t requested_size) | |
1247 { | |
1248 size_t size = 0; | |
1249 | |
1250 ggc_round_alloc_size_1 (requested_size, NULL, &size); | |
1251 return size; | |
1252 } | |
1253 | |
1254 /* Push a finalizer onto the appropriate vec. */ | |
1255 | |
1256 static void | |
1257 add_finalizer (void *result, void (*f)(void *), size_t s, size_t n) | |
1258 { | |
1259 if (f == NULL) | |
1260 /* No finalizer. */; | |
1261 else if (n == 1) | |
1262 { | |
1263 finalizer fin (result, f); | |
1264 G.finalizers[G.context_depth].safe_push (fin); | |
1265 } | |
1266 else | |
1267 { | |
1268 vec_finalizer fin (reinterpret_cast<uintptr_t> (result), f, s, n); | |
1269 G.vec_finalizers[G.context_depth].safe_push (fin); | |
1270 } | |
0 | 1271 } |
1272 | |
1273 /* Allocate a chunk of memory of SIZE bytes. Its contents are undefined. */ | |
1274 | |
1275 void * | |
111 | 1276 ggc_internal_alloc (size_t size, void (*f)(void *), size_t s, size_t n |
1277 MEM_STAT_DECL) | |
0 | 1278 { |
1279 size_t order, word, bit, object_offset, object_size; | |
1280 struct page_entry *entry; | |
1281 void *result; | |
1282 | |
111 | 1283 ggc_round_alloc_size_1 (size, &order, &object_size); |
0 | 1284 |
1285 /* If there are non-full pages for this size allocation, they are at | |
1286 the head of the list. */ | |
1287 entry = G.pages[order]; | |
1288 | |
1289 /* If there is no page for this object size, or all pages in this | |
1290 context are full, allocate a new page. */ | |
1291 if (entry == NULL || entry->num_free_objects == 0) | |
1292 { | |
1293 struct page_entry *new_entry; | |
1294 new_entry = alloc_page (order); | |
1295 | |
1296 new_entry->index_by_depth = G.by_depth_in_use; | |
1297 push_by_depth (new_entry, 0); | |
1298 | |
1299 /* We can skip context depths, if we do, make sure we go all the | |
1300 way to the new depth. */ | |
1301 while (new_entry->context_depth >= G.depth_in_use) | |
1302 push_depth (G.by_depth_in_use-1); | |
1303 | |
1304 /* If this is the only entry, it's also the tail. If it is not | |
1305 the only entry, then we must update the PREV pointer of the | |
1306 ENTRY (G.pages[order]) to point to our new page entry. */ | |
1307 if (entry == NULL) | |
1308 G.page_tails[order] = new_entry; | |
1309 else | |
1310 entry->prev = new_entry; | |
1311 | |
1312 /* Put new pages at the head of the page list. By definition the | |
1313 entry at the head of the list always has a NULL pointer. */ | |
1314 new_entry->next = entry; | |
1315 new_entry->prev = NULL; | |
1316 entry = new_entry; | |
1317 G.pages[order] = new_entry; | |
1318 | |
1319 /* For a new page, we know the word and bit positions (in the | |
1320 in_use bitmap) of the first available object -- they're zero. */ | |
1321 new_entry->next_bit_hint = 1; | |
1322 word = 0; | |
1323 bit = 0; | |
1324 object_offset = 0; | |
1325 } | |
1326 else | |
1327 { | |
1328 /* First try to use the hint left from the previous allocation | |
1329 to locate a clear bit in the in-use bitmap. We've made sure | |
1330 that the one-past-the-end bit is always set, so if the hint | |
1331 has run over, this test will fail. */ | |
1332 unsigned hint = entry->next_bit_hint; | |
1333 word = hint / HOST_BITS_PER_LONG; | |
1334 bit = hint % HOST_BITS_PER_LONG; | |
1335 | |
1336 /* If the hint didn't work, scan the bitmap from the beginning. */ | |
1337 if ((entry->in_use_p[word] >> bit) & 1) | |
1338 { | |
1339 word = bit = 0; | |
1340 while (~entry->in_use_p[word] == 0) | |
1341 ++word; | |
1342 | |
1343 #if GCC_VERSION >= 3004 | |
1344 bit = __builtin_ctzl (~entry->in_use_p[word]); | |
1345 #else | |
1346 while ((entry->in_use_p[word] >> bit) & 1) | |
1347 ++bit; | |
1348 #endif | |
1349 | |
1350 hint = word * HOST_BITS_PER_LONG + bit; | |
1351 } | |
1352 | |
1353 /* Next time, try the next bit. */ | |
1354 entry->next_bit_hint = hint + 1; | |
1355 | |
1356 object_offset = hint * object_size; | |
1357 } | |
1358 | |
1359 /* Set the in-use bit. */ | |
1360 entry->in_use_p[word] |= ((unsigned long) 1 << bit); | |
1361 | |
1362 /* Keep a running total of the number of free objects. If this page | |
1363 fills up, we may have to move it to the end of the list if the | |
1364 next page isn't full. If the next page is full, all subsequent | |
1365 pages are full, so there's no need to move it. */ | |
1366 if (--entry->num_free_objects == 0 | |
1367 && entry->next != NULL | |
1368 && entry->next->num_free_objects > 0) | |
1369 { | |
1370 /* We have a new head for the list. */ | |
1371 G.pages[order] = entry->next; | |
1372 | |
1373 /* We are moving ENTRY to the end of the page table list. | |
1374 The new page at the head of the list will have NULL in | |
1375 its PREV field and ENTRY will have NULL in its NEXT field. */ | |
1376 entry->next->prev = NULL; | |
1377 entry->next = NULL; | |
1378 | |
1379 /* Append ENTRY to the tail of the list. */ | |
1380 entry->prev = G.page_tails[order]; | |
1381 G.page_tails[order]->next = entry; | |
1382 G.page_tails[order] = entry; | |
1383 } | |
1384 | |
1385 /* Calculate the object's address. */ | |
1386 result = entry->page + object_offset; | |
111 | 1387 if (GATHER_STATISTICS) |
1388 ggc_record_overhead (OBJECT_SIZE (order), OBJECT_SIZE (order) - size, | |
1389 result FINAL_PASS_MEM_STAT); | |
0 | 1390 |
1391 #ifdef ENABLE_GC_CHECKING | |
1392 /* Keep poisoning-by-writing-0xaf the object, in an attempt to keep the | |
1393 exact same semantics in presence of memory bugs, regardless of | |
1394 ENABLE_VALGRIND_CHECKING. We override this request below. Drop the | |
1395 handle to avoid handle leak. */ | |
1396 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, object_size)); | |
1397 | |
1398 /* `Poison' the entire allocated object, including any padding at | |
1399 the end. */ | |
1400 memset (result, 0xaf, object_size); | |
1401 | |
1402 /* Make the bytes after the end of the object unaccessible. Discard the | |
1403 handle to avoid handle leak. */ | |
1404 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *) result + size, | |
1405 object_size - size)); | |
1406 #endif | |
1407 | |
1408 /* Tell Valgrind that the memory is there, but its content isn't | |
1409 defined. The bytes at the end of the object are still marked | |
1410 unaccessible. */ | |
1411 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, size)); | |
1412 | |
1413 /* Keep track of how many bytes are being allocated. This | |
1414 information is used in deciding when to collect. */ | |
1415 G.allocated += object_size; | |
1416 | |
1417 /* For timevar statistics. */ | |
1418 timevar_ggc_mem_total += object_size; | |
1419 | |
111 | 1420 if (f) |
1421 add_finalizer (result, f, s, n); | |
1422 | |
1423 if (GATHER_STATISTICS) | |
1424 { | |
1425 size_t overhead = object_size - size; | |
1426 | |
1427 G.stats.total_overhead += overhead; | |
1428 G.stats.total_allocated += object_size; | |
1429 G.stats.total_overhead_per_order[order] += overhead; | |
1430 G.stats.total_allocated_per_order[order] += object_size; | |
1431 | |
1432 if (size <= 32) | |
1433 { | |
1434 G.stats.total_overhead_under32 += overhead; | |
1435 G.stats.total_allocated_under32 += object_size; | |
1436 } | |
1437 if (size <= 64) | |
1438 { | |
1439 G.stats.total_overhead_under64 += overhead; | |
1440 G.stats.total_allocated_under64 += object_size; | |
1441 } | |
1442 if (size <= 128) | |
1443 { | |
1444 G.stats.total_overhead_under128 += overhead; | |
1445 G.stats.total_allocated_under128 += object_size; | |
1446 } | |
1447 } | |
0 | 1448 |
1449 if (GGC_DEBUG_LEVEL >= 3) | |
1450 fprintf (G.debug_file, | |
1451 "Allocating object, requested size=%lu, actual=%lu at %p on %p\n", | |
1452 (unsigned long) size, (unsigned long) object_size, result, | |
1453 (void *) entry); | |
1454 | |
1455 return result; | |
1456 } | |
1457 | |
1458 /* Mark function for strings. */ | |
1459 | |
1460 void | |
1461 gt_ggc_m_S (const void *p) | |
1462 { | |
1463 page_entry *entry; | |
1464 unsigned bit, word; | |
1465 unsigned long mask; | |
1466 unsigned long offset; | |
1467 | |
111 | 1468 if (!p) |
0 | 1469 return; |
1470 | |
111 | 1471 /* Look up the page on which the object is alloced. If it was not |
1472 GC allocated, gracefully bail out. */ | |
1473 entry = safe_lookup_page_table_entry (p); | |
1474 if (!entry) | |
1475 return; | |
0 | 1476 |
1477 /* Calculate the index of the object on the page; this is its bit | |
1478 position in the in_use_p bitmap. Note that because a char* might | |
1479 point to the middle of an object, we need special code here to | |
1480 make sure P points to the start of an object. */ | |
1481 offset = ((const char *) p - entry->page) % object_size_table[entry->order]; | |
1482 if (offset) | |
1483 { | |
1484 /* Here we've seen a char* which does not point to the beginning | |
1485 of an allocated object. We assume it points to the middle of | |
1486 a STRING_CST. */ | |
1487 gcc_assert (offset == offsetof (struct tree_string, str)); | |
1488 p = ((const char *) p) - offset; | |
1489 gt_ggc_mx_lang_tree_node (CONST_CAST (void *, p)); | |
1490 return; | |
1491 } | |
1492 | |
1493 bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order); | |
1494 word = bit / HOST_BITS_PER_LONG; | |
1495 mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG); | |
1496 | |
1497 /* If the bit was previously set, skip it. */ | |
1498 if (entry->in_use_p[word] & mask) | |
1499 return; | |
1500 | |
1501 /* Otherwise set it, and decrement the free object count. */ | |
1502 entry->in_use_p[word] |= mask; | |
1503 entry->num_free_objects -= 1; | |
1504 | |
1505 if (GGC_DEBUG_LEVEL >= 4) | |
1506 fprintf (G.debug_file, "Marking %p\n", p); | |
1507 | |
1508 return; | |
1509 } | |
1510 | |
111 | 1511 |
1512 /* User-callable entry points for marking string X. */ | |
1513 | |
1514 void | |
1515 gt_ggc_mx (const char *& x) | |
1516 { | |
1517 gt_ggc_m_S (x); | |
1518 } | |
1519 | |
1520 void | |
1521 gt_ggc_mx (unsigned char *& x) | |
1522 { | |
1523 gt_ggc_m_S (x); | |
1524 } | |
1525 | |
1526 void | |
1527 gt_ggc_mx (unsigned char& x ATTRIBUTE_UNUSED) | |
1528 { | |
1529 } | |
1530 | |
0 | 1531 /* If P is not marked, marks it and return false. Otherwise return true. |
1532 P must have been allocated by the GC allocator; it mustn't point to | |
1533 static objects, stack variables, or memory allocated with malloc. */ | |
1534 | |
1535 int | |
1536 ggc_set_mark (const void *p) | |
1537 { | |
1538 page_entry *entry; | |
1539 unsigned bit, word; | |
1540 unsigned long mask; | |
1541 | |
1542 /* Look up the page on which the object is alloced. If the object | |
1543 wasn't allocated by the collector, we'll probably die. */ | |
1544 entry = lookup_page_table_entry (p); | |
1545 gcc_assert (entry); | |
1546 | |
1547 /* Calculate the index of the object on the page; this is its bit | |
1548 position in the in_use_p bitmap. */ | |
1549 bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order); | |
1550 word = bit / HOST_BITS_PER_LONG; | |
1551 mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG); | |
1552 | |
1553 /* If the bit was previously set, skip it. */ | |
1554 if (entry->in_use_p[word] & mask) | |
1555 return 1; | |
1556 | |
1557 /* Otherwise set it, and decrement the free object count. */ | |
1558 entry->in_use_p[word] |= mask; | |
1559 entry->num_free_objects -= 1; | |
1560 | |
1561 if (GGC_DEBUG_LEVEL >= 4) | |
1562 fprintf (G.debug_file, "Marking %p\n", p); | |
1563 | |
1564 return 0; | |
1565 } | |
1566 | |
1567 /* Return 1 if P has been marked, zero otherwise. | |
1568 P must have been allocated by the GC allocator; it mustn't point to | |
1569 static objects, stack variables, or memory allocated with malloc. */ | |
1570 | |
1571 int | |
1572 ggc_marked_p (const void *p) | |
1573 { | |
1574 page_entry *entry; | |
1575 unsigned bit, word; | |
1576 unsigned long mask; | |
1577 | |
1578 /* Look up the page on which the object is alloced. If the object | |
1579 wasn't allocated by the collector, we'll probably die. */ | |
1580 entry = lookup_page_table_entry (p); | |
1581 gcc_assert (entry); | |
1582 | |
1583 /* Calculate the index of the object on the page; this is its bit | |
1584 position in the in_use_p bitmap. */ | |
1585 bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order); | |
1586 word = bit / HOST_BITS_PER_LONG; | |
1587 mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG); | |
1588 | |
1589 return (entry->in_use_p[word] & mask) != 0; | |
1590 } | |
1591 | |
1592 /* Return the size of the gc-able object P. */ | |
1593 | |
1594 size_t | |
1595 ggc_get_size (const void *p) | |
1596 { | |
1597 page_entry *pe = lookup_page_table_entry (p); | |
1598 return OBJECT_SIZE (pe->order); | |
1599 } | |
1600 | |
1601 /* Release the memory for object P. */ | |
1602 | |
1603 void | |
1604 ggc_free (void *p) | |
1605 { | |
111 | 1606 if (in_gc) |
1607 return; | |
1608 | |
0 | 1609 page_entry *pe = lookup_page_table_entry (p); |
1610 size_t order = pe->order; | |
1611 size_t size = OBJECT_SIZE (order); | |
1612 | |
111 | 1613 if (GATHER_STATISTICS) |
1614 ggc_free_overhead (p); | |
0 | 1615 |
1616 if (GGC_DEBUG_LEVEL >= 3) | |
1617 fprintf (G.debug_file, | |
1618 "Freeing object, actual size=%lu, at %p on %p\n", | |
1619 (unsigned long) size, p, (void *) pe); | |
1620 | |
1621 #ifdef ENABLE_GC_CHECKING | |
1622 /* Poison the data, to indicate the data is garbage. */ | |
1623 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (p, size)); | |
1624 memset (p, 0xa5, size); | |
1625 #endif | |
1626 /* Let valgrind know the object is free. */ | |
1627 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (p, size)); | |
1628 | |
1629 #ifdef ENABLE_GC_ALWAYS_COLLECT | |
1630 /* In the completely-anal-checking mode, we do *not* immediately free | |
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1631 the data, but instead verify that the data is *actually* not |
0 | 1632 reachable the next time we collect. */ |
1633 { | |
1634 struct free_object *fo = XNEW (struct free_object); | |
1635 fo->object = p; | |
1636 fo->next = G.free_object_list; | |
1637 G.free_object_list = fo; | |
1638 } | |
1639 #else | |
1640 { | |
1641 unsigned int bit_offset, word, bit; | |
1642 | |
1643 G.allocated -= size; | |
1644 | |
1645 /* Mark the object not-in-use. */ | |
1646 bit_offset = OFFSET_TO_BIT (((const char *) p) - pe->page, order); | |
1647 word = bit_offset / HOST_BITS_PER_LONG; | |
1648 bit = bit_offset % HOST_BITS_PER_LONG; | |
1649 pe->in_use_p[word] &= ~(1UL << bit); | |
1650 | |
1651 if (pe->num_free_objects++ == 0) | |
1652 { | |
1653 page_entry *p, *q; | |
1654 | |
1655 /* If the page is completely full, then it's supposed to | |
1656 be after all pages that aren't. Since we've freed one | |
1657 object from a page that was full, we need to move the | |
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1658 page to the head of the list. |
0 | 1659 |
1660 PE is the node we want to move. Q is the previous node | |
1661 and P is the next node in the list. */ | |
1662 q = pe->prev; | |
1663 if (q && q->num_free_objects == 0) | |
1664 { | |
1665 p = pe->next; | |
1666 | |
1667 q->next = p; | |
1668 | |
1669 /* If PE was at the end of the list, then Q becomes the | |
1670 new end of the list. If PE was not the end of the | |
1671 list, then we need to update the PREV field for P. */ | |
1672 if (!p) | |
1673 G.page_tails[order] = q; | |
1674 else | |
1675 p->prev = q; | |
1676 | |
1677 /* Move PE to the head of the list. */ | |
1678 pe->next = G.pages[order]; | |
1679 pe->prev = NULL; | |
1680 G.pages[order]->prev = pe; | |
1681 G.pages[order] = pe; | |
1682 } | |
1683 | |
1684 /* Reset the hint bit to point to the only free object. */ | |
1685 pe->next_bit_hint = bit_offset; | |
1686 } | |
1687 } | |
1688 #endif | |
1689 } | |
1690 | |
1691 /* Subroutine of init_ggc which computes the pair of numbers used to | |
1692 perform division by OBJECT_SIZE (order) and fills in inverse_table[]. | |
1693 | |
1694 This algorithm is taken from Granlund and Montgomery's paper | |
1695 "Division by Invariant Integers using Multiplication" | |
1696 (Proc. SIGPLAN PLDI, 1994), section 9 (Exact division by | |
1697 constants). */ | |
1698 | |
1699 static void | |
1700 compute_inverse (unsigned order) | |
1701 { | |
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1702 size_t size, inv; |
0 | 1703 unsigned int e; |
1704 | |
1705 size = OBJECT_SIZE (order); | |
1706 e = 0; | |
1707 while (size % 2 == 0) | |
1708 { | |
1709 e++; | |
1710 size >>= 1; | |
1711 } | |
1712 | |
1713 inv = size; | |
1714 while (inv * size != 1) | |
1715 inv = inv * (2 - inv*size); | |
1716 | |
1717 DIV_MULT (order) = inv; | |
1718 DIV_SHIFT (order) = e; | |
1719 } | |
1720 | |
1721 /* Initialize the ggc-mmap allocator. */ | |
1722 void | |
1723 init_ggc (void) | |
1724 { | |
111 | 1725 static bool init_p = false; |
0 | 1726 unsigned order; |
1727 | |
111 | 1728 if (init_p) |
1729 return; | |
1730 init_p = true; | |
1731 | |
1732 G.pagesize = getpagesize (); | |
0 | 1733 G.lg_pagesize = exact_log2 (G.pagesize); |
1734 | |
1735 #ifdef HAVE_MMAP_DEV_ZERO | |
1736 G.dev_zero_fd = open ("/dev/zero", O_RDONLY); | |
1737 if (G.dev_zero_fd == -1) | |
1738 internal_error ("open /dev/zero: %m"); | |
1739 #endif | |
1740 | |
1741 #if 0 | |
1742 G.debug_file = fopen ("ggc-mmap.debug", "w"); | |
1743 #else | |
1744 G.debug_file = stdout; | |
1745 #endif | |
1746 | |
1747 #ifdef USING_MMAP | |
1748 /* StunOS has an amazing off-by-one error for the first mmap allocation | |
1749 after fiddling with RLIMIT_STACK. The result, as hard as it is to | |
1750 believe, is an unaligned page allocation, which would cause us to | |
1751 hork badly if we tried to use it. */ | |
1752 { | |
111 | 1753 char *p = alloc_anon (NULL, G.pagesize, true); |
0 | 1754 struct page_entry *e; |
111 | 1755 if ((uintptr_t)p & (G.pagesize - 1)) |
0 | 1756 { |
1757 /* How losing. Discard this one and try another. If we still | |
1758 can't get something useful, give up. */ | |
1759 | |
111 | 1760 p = alloc_anon (NULL, G.pagesize, true); |
1761 gcc_assert (!((uintptr_t)p & (G.pagesize - 1))); | |
0 | 1762 } |
1763 | |
1764 /* We have a good page, might as well hold onto it... */ | |
1765 e = XCNEW (struct page_entry); | |
1766 e->bytes = G.pagesize; | |
1767 e->page = p; | |
1768 e->next = G.free_pages; | |
1769 G.free_pages = e; | |
1770 } | |
1771 #endif | |
1772 | |
1773 /* Initialize the object size table. */ | |
1774 for (order = 0; order < HOST_BITS_PER_PTR; ++order) | |
1775 object_size_table[order] = (size_t) 1 << order; | |
1776 for (order = HOST_BITS_PER_PTR; order < NUM_ORDERS; ++order) | |
1777 { | |
1778 size_t s = extra_order_size_table[order - HOST_BITS_PER_PTR]; | |
1779 | |
1780 /* If S is not a multiple of the MAX_ALIGNMENT, then round it up | |
1781 so that we're sure of getting aligned memory. */ | |
1782 s = ROUND_UP (s, MAX_ALIGNMENT); | |
1783 object_size_table[order] = s; | |
1784 } | |
1785 | |
1786 /* Initialize the objects-per-page and inverse tables. */ | |
1787 for (order = 0; order < NUM_ORDERS; ++order) | |
1788 { | |
1789 objects_per_page_table[order] = G.pagesize / OBJECT_SIZE (order); | |
1790 if (objects_per_page_table[order] == 0) | |
1791 objects_per_page_table[order] = 1; | |
1792 compute_inverse (order); | |
1793 } | |
1794 | |
1795 /* Reset the size_lookup array to put appropriately sized objects in | |
1796 the special orders. All objects bigger than the previous power | |
1797 of two, but no greater than the special size, should go in the | |
1798 new order. */ | |
1799 for (order = HOST_BITS_PER_PTR; order < NUM_ORDERS; ++order) | |
1800 { | |
1801 int o; | |
1802 int i; | |
1803 | |
1804 i = OBJECT_SIZE (order); | |
1805 if (i >= NUM_SIZE_LOOKUP) | |
1806 continue; | |
1807 | |
1808 for (o = size_lookup[i]; o == size_lookup [i]; --i) | |
1809 size_lookup[i] = order; | |
1810 } | |
1811 | |
1812 G.depth_in_use = 0; | |
1813 G.depth_max = 10; | |
1814 G.depth = XNEWVEC (unsigned int, G.depth_max); | |
1815 | |
1816 G.by_depth_in_use = 0; | |
1817 G.by_depth_max = INITIAL_PTE_COUNT; | |
1818 G.by_depth = XNEWVEC (page_entry *, G.by_depth_max); | |
1819 G.save_in_use = XNEWVEC (unsigned long *, G.by_depth_max); | |
111 | 1820 |
1821 /* Allocate space for the depth 0 finalizers. */ | |
1822 G.finalizers.safe_push (vNULL); | |
1823 G.vec_finalizers.safe_push (vNULL); | |
1824 gcc_assert (G.finalizers.length() == 1); | |
0 | 1825 } |
1826 | |
1827 /* Merge the SAVE_IN_USE_P and IN_USE_P arrays in P so that IN_USE_P | |
1828 reflects reality. Recalculate NUM_FREE_OBJECTS as well. */ | |
1829 | |
1830 static void | |
1831 ggc_recalculate_in_use_p (page_entry *p) | |
1832 { | |
1833 unsigned int i; | |
1834 size_t num_objects; | |
1835 | |
1836 /* Because the past-the-end bit in in_use_p is always set, we | |
1837 pretend there is one additional object. */ | |
1838 num_objects = OBJECTS_IN_PAGE (p) + 1; | |
1839 | |
1840 /* Reset the free object count. */ | |
1841 p->num_free_objects = num_objects; | |
1842 | |
1843 /* Combine the IN_USE_P and SAVE_IN_USE_P arrays. */ | |
1844 for (i = 0; | |
1845 i < CEIL (BITMAP_SIZE (num_objects), | |
1846 sizeof (*p->in_use_p)); | |
1847 ++i) | |
1848 { | |
1849 unsigned long j; | |
1850 | |
1851 /* Something is in use if it is marked, or if it was in use in a | |
1852 context further down the context stack. */ | |
1853 p->in_use_p[i] |= save_in_use_p (p)[i]; | |
1854 | |
1855 /* Decrement the free object count for every object allocated. */ | |
1856 for (j = p->in_use_p[i]; j; j >>= 1) | |
1857 p->num_free_objects -= (j & 1); | |
1858 } | |
1859 | |
1860 gcc_assert (p->num_free_objects < num_objects); | |
1861 } | |
1862 | |
1863 /* Unmark all objects. */ | |
1864 | |
1865 static void | |
1866 clear_marks (void) | |
1867 { | |
1868 unsigned order; | |
1869 | |
1870 for (order = 2; order < NUM_ORDERS; order++) | |
1871 { | |
1872 page_entry *p; | |
1873 | |
1874 for (p = G.pages[order]; p != NULL; p = p->next) | |
1875 { | |
1876 size_t num_objects = OBJECTS_IN_PAGE (p); | |
1877 size_t bitmap_size = BITMAP_SIZE (num_objects + 1); | |
1878 | |
1879 /* The data should be page-aligned. */ | |
111 | 1880 gcc_assert (!((uintptr_t) p->page & (G.pagesize - 1))); |
0 | 1881 |
1882 /* Pages that aren't in the topmost context are not collected; | |
1883 nevertheless, we need their in-use bit vectors to store GC | |
1884 marks. So, back them up first. */ | |
1885 if (p->context_depth < G.context_depth) | |
1886 { | |
1887 if (! save_in_use_p (p)) | |
1888 save_in_use_p (p) = XNEWVAR (unsigned long, bitmap_size); | |
1889 memcpy (save_in_use_p (p), p->in_use_p, bitmap_size); | |
1890 } | |
1891 | |
1892 /* Reset reset the number of free objects and clear the | |
1893 in-use bits. These will be adjusted by mark_obj. */ | |
1894 p->num_free_objects = num_objects; | |
1895 memset (p->in_use_p, 0, bitmap_size); | |
1896 | |
1897 /* Make sure the one-past-the-end bit is always set. */ | |
1898 p->in_use_p[num_objects / HOST_BITS_PER_LONG] | |
1899 = ((unsigned long) 1 << (num_objects % HOST_BITS_PER_LONG)); | |
1900 } | |
1901 } | |
1902 } | |
1903 | |
111 | 1904 /* Check if any blocks with a registered finalizer have become unmarked. If so |
1905 run the finalizer and unregister it because the block is about to be freed. | |
1906 Note that no garantee is made about what order finalizers will run in so | |
1907 touching other objects in gc memory is extremely unwise. */ | |
1908 | |
1909 static void | |
1910 ggc_handle_finalizers () | |
1911 { | |
1912 unsigned dlen = G.finalizers.length(); | |
1913 for (unsigned d = G.context_depth; d < dlen; ++d) | |
1914 { | |
1915 vec<finalizer> &v = G.finalizers[d]; | |
1916 unsigned length = v.length (); | |
1917 for (unsigned int i = 0; i < length;) | |
1918 { | |
1919 finalizer &f = v[i]; | |
1920 if (!ggc_marked_p (f.addr ())) | |
1921 { | |
1922 f.call (); | |
1923 v.unordered_remove (i); | |
1924 length--; | |
1925 } | |
1926 else | |
1927 i++; | |
1928 } | |
1929 } | |
1930 | |
1931 gcc_assert (dlen == G.vec_finalizers.length()); | |
1932 for (unsigned d = G.context_depth; d < dlen; ++d) | |
1933 { | |
1934 vec<vec_finalizer> &vv = G.vec_finalizers[d]; | |
1935 unsigned length = vv.length (); | |
1936 for (unsigned int i = 0; i < length;) | |
1937 { | |
1938 vec_finalizer &f = vv[i]; | |
1939 if (!ggc_marked_p (f.addr ())) | |
1940 { | |
1941 f.call (); | |
1942 vv.unordered_remove (i); | |
1943 length--; | |
1944 } | |
1945 else | |
1946 i++; | |
1947 } | |
1948 } | |
1949 } | |
1950 | |
0 | 1951 /* Free all empty pages. Partially empty pages need no attention |
1952 because the `mark' bit doubles as an `unused' bit. */ | |
1953 | |
1954 static void | |
1955 sweep_pages (void) | |
1956 { | |
1957 unsigned order; | |
1958 | |
1959 for (order = 2; order < NUM_ORDERS; order++) | |
1960 { | |
1961 /* The last page-entry to consider, regardless of entries | |
1962 placed at the end of the list. */ | |
1963 page_entry * const last = G.page_tails[order]; | |
1964 | |
1965 size_t num_objects; | |
1966 size_t live_objects; | |
1967 page_entry *p, *previous; | |
1968 int done; | |
1969 | |
1970 p = G.pages[order]; | |
1971 if (p == NULL) | |
1972 continue; | |
1973 | |
1974 previous = NULL; | |
1975 do | |
1976 { | |
1977 page_entry *next = p->next; | |
1978 | |
1979 /* Loop until all entries have been examined. */ | |
1980 done = (p == last); | |
1981 | |
1982 num_objects = OBJECTS_IN_PAGE (p); | |
1983 | |
1984 /* Add all live objects on this page to the count of | |
1985 allocated memory. */ | |
1986 live_objects = num_objects - p->num_free_objects; | |
1987 | |
1988 G.allocated += OBJECT_SIZE (order) * live_objects; | |
1989 | |
1990 /* Only objects on pages in the topmost context should get | |
1991 collected. */ | |
1992 if (p->context_depth < G.context_depth) | |
1993 ; | |
1994 | |
1995 /* Remove the page if it's empty. */ | |
1996 else if (live_objects == 0) | |
1997 { | |
1998 /* If P was the first page in the list, then NEXT | |
1999 becomes the new first page in the list, otherwise | |
2000 splice P out of the forward pointers. */ | |
2001 if (! previous) | |
2002 G.pages[order] = next; | |
2003 else | |
2004 previous->next = next; | |
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2005 |
0 | 2006 /* Splice P out of the back pointers too. */ |
2007 if (next) | |
2008 next->prev = previous; | |
2009 | |
2010 /* Are we removing the last element? */ | |
2011 if (p == G.page_tails[order]) | |
2012 G.page_tails[order] = previous; | |
2013 free_page (p); | |
2014 p = previous; | |
2015 } | |
2016 | |
2017 /* If the page is full, move it to the end. */ | |
2018 else if (p->num_free_objects == 0) | |
2019 { | |
2020 /* Don't move it if it's already at the end. */ | |
2021 if (p != G.page_tails[order]) | |
2022 { | |
2023 /* Move p to the end of the list. */ | |
2024 p->next = NULL; | |
2025 p->prev = G.page_tails[order]; | |
2026 G.page_tails[order]->next = p; | |
2027 | |
2028 /* Update the tail pointer... */ | |
2029 G.page_tails[order] = p; | |
2030 | |
2031 /* ... and the head pointer, if necessary. */ | |
2032 if (! previous) | |
2033 G.pages[order] = next; | |
2034 else | |
2035 previous->next = next; | |
2036 | |
2037 /* And update the backpointer in NEXT if necessary. */ | |
2038 if (next) | |
2039 next->prev = previous; | |
2040 | |
2041 p = previous; | |
2042 } | |
2043 } | |
2044 | |
2045 /* If we've fallen through to here, it's a page in the | |
2046 topmost context that is neither full nor empty. Such a | |
2047 page must precede pages at lesser context depth in the | |
2048 list, so move it to the head. */ | |
2049 else if (p != G.pages[order]) | |
2050 { | |
2051 previous->next = p->next; | |
2052 | |
2053 /* Update the backchain in the next node if it exists. */ | |
2054 if (p->next) | |
2055 p->next->prev = previous; | |
2056 | |
2057 /* Move P to the head of the list. */ | |
2058 p->next = G.pages[order]; | |
2059 p->prev = NULL; | |
2060 G.pages[order]->prev = p; | |
2061 | |
2062 /* Update the head pointer. */ | |
2063 G.pages[order] = p; | |
2064 | |
2065 /* Are we moving the last element? */ | |
2066 if (G.page_tails[order] == p) | |
2067 G.page_tails[order] = previous; | |
2068 p = previous; | |
2069 } | |
2070 | |
2071 previous = p; | |
2072 p = next; | |
2073 } | |
2074 while (! done); | |
2075 | |
2076 /* Now, restore the in_use_p vectors for any pages from contexts | |
2077 other than the current one. */ | |
2078 for (p = G.pages[order]; p; p = p->next) | |
2079 if (p->context_depth != G.context_depth) | |
2080 ggc_recalculate_in_use_p (p); | |
2081 } | |
2082 } | |
2083 | |
2084 #ifdef ENABLE_GC_CHECKING | |
2085 /* Clobber all free objects. */ | |
2086 | |
2087 static void | |
2088 poison_pages (void) | |
2089 { | |
2090 unsigned order; | |
2091 | |
2092 for (order = 2; order < NUM_ORDERS; order++) | |
2093 { | |
2094 size_t size = OBJECT_SIZE (order); | |
2095 page_entry *p; | |
2096 | |
2097 for (p = G.pages[order]; p != NULL; p = p->next) | |
2098 { | |
2099 size_t num_objects; | |
2100 size_t i; | |
2101 | |
2102 if (p->context_depth != G.context_depth) | |
2103 /* Since we don't do any collection for pages in pushed | |
2104 contexts, there's no need to do any poisoning. And | |
2105 besides, the IN_USE_P array isn't valid until we pop | |
2106 contexts. */ | |
2107 continue; | |
2108 | |
2109 num_objects = OBJECTS_IN_PAGE (p); | |
2110 for (i = 0; i < num_objects; i++) | |
2111 { | |
2112 size_t word, bit; | |
2113 word = i / HOST_BITS_PER_LONG; | |
2114 bit = i % HOST_BITS_PER_LONG; | |
2115 if (((p->in_use_p[word] >> bit) & 1) == 0) | |
2116 { | |
2117 char *object = p->page + i * size; | |
2118 | |
2119 /* Keep poison-by-write when we expect to use Valgrind, | |
2120 so the exact same memory semantics is kept, in case | |
2121 there are memory errors. We override this request | |
2122 below. */ | |
2123 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (object, | |
2124 size)); | |
2125 memset (object, 0xa5, size); | |
2126 | |
2127 /* Drop the handle to avoid handle leak. */ | |
2128 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (object, size)); | |
2129 } | |
2130 } | |
2131 } | |
2132 } | |
2133 } | |
2134 #else | |
2135 #define poison_pages() | |
2136 #endif | |
2137 | |
2138 #ifdef ENABLE_GC_ALWAYS_COLLECT | |
2139 /* Validate that the reportedly free objects actually are. */ | |
2140 | |
2141 static void | |
2142 validate_free_objects (void) | |
2143 { | |
2144 struct free_object *f, *next, *still_free = NULL; | |
2145 | |
2146 for (f = G.free_object_list; f ; f = next) | |
2147 { | |
2148 page_entry *pe = lookup_page_table_entry (f->object); | |
2149 size_t bit, word; | |
2150 | |
2151 bit = OFFSET_TO_BIT ((char *)f->object - pe->page, pe->order); | |
2152 word = bit / HOST_BITS_PER_LONG; | |
2153 bit = bit % HOST_BITS_PER_LONG; | |
2154 next = f->next; | |
2155 | |
2156 /* Make certain it isn't visible from any root. Notice that we | |
2157 do this check before sweep_pages merges save_in_use_p. */ | |
2158 gcc_assert (!(pe->in_use_p[word] & (1UL << bit))); | |
2159 | |
2160 /* If the object comes from an outer context, then retain the | |
2161 free_object entry, so that we can verify that the address | |
2162 isn't live on the stack in some outer context. */ | |
2163 if (pe->context_depth != G.context_depth) | |
2164 { | |
2165 f->next = still_free; | |
2166 still_free = f; | |
2167 } | |
2168 else | |
2169 free (f); | |
2170 } | |
2171 | |
2172 G.free_object_list = still_free; | |
2173 } | |
2174 #else | |
2175 #define validate_free_objects() | |
2176 #endif | |
2177 | |
2178 /* Top level mark-and-sweep routine. */ | |
2179 | |
2180 void | |
2181 ggc_collect (void) | |
2182 { | |
2183 /* Avoid frequent unnecessary work by skipping collection if the | |
2184 total allocations haven't expanded much since the last | |
2185 collection. */ | |
2186 float allocated_last_gc = | |
145 | 2187 MAX (G.allocated_last_gc, (size_t)param_ggc_min_heapsize * 1024); |
2188 | |
2189 /* It is also good time to get memory block pool into limits. */ | |
2190 memory_block_pool::trim (); | |
2191 | |
2192 float min_expand = allocated_last_gc * param_ggc_min_expand / 100; | |
0 | 2193 if (G.allocated < allocated_last_gc + min_expand && !ggc_force_collect) |
2194 return; | |
2195 | |
2196 timevar_push (TV_GC); | |
2197 if (GGC_DEBUG_LEVEL >= 2) | |
2198 fprintf (G.debug_file, "BEGIN COLLECTING\n"); | |
2199 | |
2200 /* Zero the total allocated bytes. This will be recalculated in the | |
2201 sweep phase. */ | |
145 | 2202 size_t allocated = G.allocated; |
0 | 2203 G.allocated = 0; |
2204 | |
2205 /* Release the pages we freed the last time we collected, but didn't | |
2206 reuse in the interim. */ | |
2207 release_pages (); | |
2208 | |
145 | 2209 /* Output this later so we do not interfere with release_pages. */ |
2210 if (!quiet_flag) | |
2211 fprintf (stderr, " {GC %luk -> ", (unsigned long) allocated / 1024); | |
2212 | |
0 | 2213 /* Indicate that we've seen collections at this context depth. */ |
2214 G.context_depth_collections = ((unsigned long)1 << (G.context_depth + 1)) - 1; | |
2215 | |
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2216 invoke_plugin_callbacks (PLUGIN_GGC_START, NULL); |
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2217 |
111 | 2218 in_gc = true; |
0 | 2219 clear_marks (); |
2220 ggc_mark_roots (); | |
111 | 2221 ggc_handle_finalizers (); |
2222 | |
2223 if (GATHER_STATISTICS) | |
2224 ggc_prune_overhead_list (); | |
2225 | |
0 | 2226 poison_pages (); |
2227 validate_free_objects (); | |
2228 sweep_pages (); | |
2229 | |
111 | 2230 in_gc = false; |
0 | 2231 G.allocated_last_gc = G.allocated; |
2232 | |
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2233 invoke_plugin_callbacks (PLUGIN_GGC_END, NULL); |
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2234 |
0 | 2235 timevar_pop (TV_GC); |
2236 | |
2237 if (!quiet_flag) | |
2238 fprintf (stderr, "%luk}", (unsigned long) G.allocated / 1024); | |
2239 if (GGC_DEBUG_LEVEL >= 2) | |
2240 fprintf (G.debug_file, "END COLLECTING\n"); | |
2241 } | |
2242 | |
145 | 2243 /* Return free pages to the system. */ |
2244 | |
2245 void | |
2246 ggc_trim () | |
2247 { | |
2248 timevar_push (TV_GC); | |
2249 G.allocated = 0; | |
2250 sweep_pages (); | |
2251 release_pages (); | |
2252 if (!quiet_flag) | |
2253 fprintf (stderr, " {GC trimmed to %luk, %luk mapped}", | |
2254 (unsigned long) G.allocated / 1024, | |
2255 (unsigned long) G.bytes_mapped / 1024); | |
2256 timevar_pop (TV_GC); | |
2257 } | |
2258 | |
2259 /* Assume that all GGC memory is reachable and grow the limits for next | |
2260 collection. With checking, trigger GGC so -Q compilation outputs how much | |
2261 of memory really is reachable. */ | |
111 | 2262 |
2263 void | |
2264 ggc_grow (void) | |
2265 { | |
2266 if (!flag_checking) | |
2267 G.allocated_last_gc = MAX (G.allocated_last_gc, | |
2268 G.allocated); | |
2269 else | |
2270 ggc_collect (); | |
2271 if (!quiet_flag) | |
145 | 2272 fprintf (stderr, " {GC %luk} ", (unsigned long) G.allocated / 1024); |
111 | 2273 } |
2274 | |
0 | 2275 void |
2276 ggc_print_statistics (void) | |
2277 { | |
2278 struct ggc_statistics stats; | |
2279 unsigned int i; | |
2280 size_t total_overhead = 0; | |
2281 | |
2282 /* Clear the statistics. */ | |
2283 memset (&stats, 0, sizeof (stats)); | |
2284 | |
2285 /* Make sure collection will really occur. */ | |
2286 G.allocated_last_gc = 0; | |
2287 | |
2288 /* Collect and print the statistics common across collectors. */ | |
2289 ggc_print_common_statistics (stderr, &stats); | |
2290 | |
2291 /* Release free pages so that we will not count the bytes allocated | |
2292 there as part of the total allocated memory. */ | |
2293 release_pages (); | |
2294 | |
2295 /* Collect some information about the various sizes of | |
2296 allocation. */ | |
2297 fprintf (stderr, | |
2298 "Memory still allocated at the end of the compilation process\n"); | |
111 | 2299 fprintf (stderr, "%-8s %10s %10s %10s\n", |
0 | 2300 "Size", "Allocated", "Used", "Overhead"); |
2301 for (i = 0; i < NUM_ORDERS; ++i) | |
2302 { | |
2303 page_entry *p; | |
2304 size_t allocated; | |
2305 size_t in_use; | |
2306 size_t overhead; | |
2307 | |
2308 /* Skip empty entries. */ | |
2309 if (!G.pages[i]) | |
2310 continue; | |
2311 | |
2312 overhead = allocated = in_use = 0; | |
2313 | |
2314 /* Figure out the total number of bytes allocated for objects of | |
2315 this size, and how many of them are actually in use. Also figure | |
2316 out how much memory the page table is using. */ | |
2317 for (p = G.pages[i]; p; p = p->next) | |
2318 { | |
2319 allocated += p->bytes; | |
2320 in_use += | |
2321 (OBJECTS_IN_PAGE (p) - p->num_free_objects) * OBJECT_SIZE (i); | |
2322 | |
2323 overhead += (sizeof (page_entry) - sizeof (long) | |
2324 + BITMAP_SIZE (OBJECTS_IN_PAGE (p) + 1)); | |
2325 } | |
145 | 2326 fprintf (stderr, "%-8" PRIu64 " " PRsa (10) " " PRsa (10) " " |
2327 PRsa (10) "\n", | |
2328 (uint64_t)OBJECT_SIZE (i), | |
2329 SIZE_AMOUNT (allocated), | |
2330 SIZE_AMOUNT (in_use), | |
2331 SIZE_AMOUNT (overhead)); | |
0 | 2332 total_overhead += overhead; |
2333 } | |
145 | 2334 fprintf (stderr, "%-8s " PRsa (10) " " PRsa (10) " " PRsa (10) "\n", |
2335 "Total", | |
2336 SIZE_AMOUNT (G.bytes_mapped), | |
2337 SIZE_AMOUNT (G.allocated), | |
2338 SIZE_AMOUNT (total_overhead)); | |
0 | 2339 |
111 | 2340 if (GATHER_STATISTICS) |
2341 { | |
2342 fprintf (stderr, "\nTotal allocations and overheads during " | |
2343 "the compilation process\n"); | |
2344 | |
145 | 2345 fprintf (stderr, "Total Overhead: " |
2346 PRsa (9) "\n", | |
2347 SIZE_AMOUNT (G.stats.total_overhead)); | |
2348 fprintf (stderr, "Total Allocated: " | |
2349 PRsa (9) "\n", | |
2350 SIZE_AMOUNT (G.stats.total_allocated)); | |
2351 | |
2352 fprintf (stderr, "Total Overhead under 32B: " | |
2353 PRsa (9) "\n", | |
2354 SIZE_AMOUNT (G.stats.total_overhead_under32)); | |
2355 fprintf (stderr, "Total Allocated under 32B: " | |
2356 PRsa (9) "\n", | |
2357 SIZE_AMOUNT (G.stats.total_allocated_under32)); | |
2358 fprintf (stderr, "Total Overhead under 64B: " | |
2359 PRsa (9) "\n", | |
2360 SIZE_AMOUNT (G.stats.total_overhead_under64)); | |
2361 fprintf (stderr, "Total Allocated under 64B: " | |
2362 PRsa (9) "\n", | |
2363 SIZE_AMOUNT (G.stats.total_allocated_under64)); | |
2364 fprintf (stderr, "Total Overhead under 128B: " | |
2365 PRsa (9) "\n", | |
2366 SIZE_AMOUNT (G.stats.total_overhead_under128)); | |
2367 fprintf (stderr, "Total Allocated under 128B: " | |
2368 PRsa (9) "\n", | |
2369 SIZE_AMOUNT (G.stats.total_allocated_under128)); | |
111 | 2370 |
2371 for (i = 0; i < NUM_ORDERS; i++) | |
2372 if (G.stats.total_allocated_per_order[i]) | |
2373 { | |
145 | 2374 fprintf (stderr, "Total Overhead page size %9" PRIu64 ": " |
2375 PRsa (9) "\n", | |
2376 (uint64_t)OBJECT_SIZE (i), | |
2377 SIZE_AMOUNT (G.stats.total_overhead_per_order[i])); | |
2378 fprintf (stderr, "Total Allocated page size %9" PRIu64 ": " | |
2379 PRsa (9) "\n", | |
2380 (uint64_t)OBJECT_SIZE (i), | |
2381 SIZE_AMOUNT (G.stats.total_allocated_per_order[i])); | |
111 | 2382 } |
0 | 2383 } |
2384 } | |
2385 | |
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2386 struct ggc_pch_ondisk |
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2387 { |
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2388 unsigned totals[NUM_ORDERS]; |
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2389 }; |
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2390 |
0 | 2391 struct ggc_pch_data |
2392 { | |
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2393 struct ggc_pch_ondisk d; |
111 | 2394 uintptr_t base[NUM_ORDERS]; |
0 | 2395 size_t written[NUM_ORDERS]; |
2396 }; | |
2397 | |
2398 struct ggc_pch_data * | |
2399 init_ggc_pch (void) | |
2400 { | |
2401 return XCNEW (struct ggc_pch_data); | |
2402 } | |
2403 | |
2404 void | |
2405 ggc_pch_count_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, | |
111 | 2406 size_t size, bool is_string ATTRIBUTE_UNUSED) |
0 | 2407 { |
2408 unsigned order; | |
2409 | |
2410 if (size < NUM_SIZE_LOOKUP) | |
2411 order = size_lookup[size]; | |
2412 else | |
2413 { | |
2414 order = 10; | |
2415 while (size > OBJECT_SIZE (order)) | |
2416 order++; | |
2417 } | |
2418 | |
2419 d->d.totals[order]++; | |
2420 } | |
2421 | |
2422 size_t | |
2423 ggc_pch_total_size (struct ggc_pch_data *d) | |
2424 { | |
2425 size_t a = 0; | |
2426 unsigned i; | |
2427 | |
2428 for (i = 0; i < NUM_ORDERS; i++) | |
111 | 2429 a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i)); |
0 | 2430 return a; |
2431 } | |
2432 | |
2433 void | |
2434 ggc_pch_this_base (struct ggc_pch_data *d, void *base) | |
2435 { | |
111 | 2436 uintptr_t a = (uintptr_t) base; |
0 | 2437 unsigned i; |
2438 | |
2439 for (i = 0; i < NUM_ORDERS; i++) | |
2440 { | |
2441 d->base[i] = a; | |
111 | 2442 a += PAGE_ALIGN (d->d.totals[i] * OBJECT_SIZE (i)); |
0 | 2443 } |
2444 } | |
2445 | |
2446 | |
2447 char * | |
2448 ggc_pch_alloc_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, | |
111 | 2449 size_t size, bool is_string ATTRIBUTE_UNUSED) |
0 | 2450 { |
2451 unsigned order; | |
2452 char *result; | |
2453 | |
2454 if (size < NUM_SIZE_LOOKUP) | |
2455 order = size_lookup[size]; | |
2456 else | |
2457 { | |
2458 order = 10; | |
2459 while (size > OBJECT_SIZE (order)) | |
2460 order++; | |
2461 } | |
2462 | |
2463 result = (char *) d->base[order]; | |
2464 d->base[order] += OBJECT_SIZE (order); | |
2465 return result; | |
2466 } | |
2467 | |
2468 void | |
2469 ggc_pch_prepare_write (struct ggc_pch_data *d ATTRIBUTE_UNUSED, | |
2470 FILE *f ATTRIBUTE_UNUSED) | |
2471 { | |
2472 /* Nothing to do. */ | |
2473 } | |
2474 | |
2475 void | |
111 | 2476 ggc_pch_write_object (struct ggc_pch_data *d, |
0 | 2477 FILE *f, void *x, void *newx ATTRIBUTE_UNUSED, |
2478 size_t size, bool is_string ATTRIBUTE_UNUSED) | |
2479 { | |
2480 unsigned order; | |
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2481 static const char emptyBytes[256] = { 0 }; |
0 | 2482 |
2483 if (size < NUM_SIZE_LOOKUP) | |
2484 order = size_lookup[size]; | |
2485 else | |
2486 { | |
2487 order = 10; | |
2488 while (size > OBJECT_SIZE (order)) | |
2489 order++; | |
2490 } | |
2491 | |
2492 if (fwrite (x, size, 1, f) != 1) | |
145 | 2493 fatal_error (input_location, "cannot write PCH file: %m"); |
0 | 2494 |
2495 /* If SIZE is not the same as OBJECT_SIZE(order), then we need to pad the | |
2496 object out to OBJECT_SIZE(order). This happens for strings. */ | |
2497 | |
2498 if (size != OBJECT_SIZE (order)) | |
2499 { | |
111 | 2500 unsigned padding = OBJECT_SIZE (order) - size; |
0 | 2501 |
2502 /* To speed small writes, we use a nulled-out array that's larger | |
2503 than most padding requests as the source for our null bytes. This | |
2504 permits us to do the padding with fwrite() rather than fseek(), and | |
2505 limits the chance the OS may try to flush any outstanding writes. */ | |
111 | 2506 if (padding <= sizeof (emptyBytes)) |
0 | 2507 { |
2508 if (fwrite (emptyBytes, 1, padding, f) != padding) | |
145 | 2509 fatal_error (input_location, "cannot write PCH file"); |
0 | 2510 } |
2511 else | |
2512 { | |
2513 /* Larger than our buffer? Just default to fseek. */ | |
2514 if (fseek (f, padding, SEEK_CUR) != 0) | |
145 | 2515 fatal_error (input_location, "cannot write PCH file"); |
0 | 2516 } |
2517 } | |
2518 | |
2519 d->written[order]++; | |
2520 if (d->written[order] == d->d.totals[order] | |
2521 && fseek (f, ROUND_UP_VALUE (d->d.totals[order] * OBJECT_SIZE (order), | |
2522 G.pagesize), | |
2523 SEEK_CUR) != 0) | |
145 | 2524 fatal_error (input_location, "cannot write PCH file: %m"); |
0 | 2525 } |
2526 | |
2527 void | |
2528 ggc_pch_finish (struct ggc_pch_data *d, FILE *f) | |
2529 { | |
2530 if (fwrite (&d->d, sizeof (d->d), 1, f) != 1) | |
145 | 2531 fatal_error (input_location, "cannot write PCH file: %m"); |
0 | 2532 free (d); |
2533 } | |
2534 | |
2535 /* Move the PCH PTE entries just added to the end of by_depth, to the | |
2536 front. */ | |
2537 | |
2538 static void | |
2539 move_ptes_to_front (int count_old_page_tables, int count_new_page_tables) | |
2540 { | |
2541 /* First, we swap the new entries to the front of the varrays. */ | |
2542 page_entry **new_by_depth; | |
2543 unsigned long **new_save_in_use; | |
2544 | |
2545 new_by_depth = XNEWVEC (page_entry *, G.by_depth_max); | |
2546 new_save_in_use = XNEWVEC (unsigned long *, G.by_depth_max); | |
2547 | |
2548 memcpy (&new_by_depth[0], | |
2549 &G.by_depth[count_old_page_tables], | |
2550 count_new_page_tables * sizeof (void *)); | |
2551 memcpy (&new_by_depth[count_new_page_tables], | |
2552 &G.by_depth[0], | |
2553 count_old_page_tables * sizeof (void *)); | |
2554 memcpy (&new_save_in_use[0], | |
2555 &G.save_in_use[count_old_page_tables], | |
2556 count_new_page_tables * sizeof (void *)); | |
2557 memcpy (&new_save_in_use[count_new_page_tables], | |
2558 &G.save_in_use[0], | |
2559 count_old_page_tables * sizeof (void *)); | |
2560 | |
2561 free (G.by_depth); | |
2562 free (G.save_in_use); | |
2563 | |
2564 G.by_depth = new_by_depth; | |
2565 G.save_in_use = new_save_in_use; | |
2566 | |
2567 /* Now update all the index_by_depth fields. */ | |
111 | 2568 for (unsigned i = G.by_depth_in_use; i--;) |
0 | 2569 { |
111 | 2570 page_entry *p = G.by_depth[i]; |
2571 p->index_by_depth = i; | |
0 | 2572 } |
2573 | |
2574 /* And last, we update the depth pointers in G.depth. The first | |
2575 entry is already 0, and context 0 entries always start at index | |
2576 0, so there is nothing to update in the first slot. We need a | |
2577 second slot, only if we have old ptes, and if we do, they start | |
2578 at index count_new_page_tables. */ | |
2579 if (count_old_page_tables) | |
2580 push_depth (count_new_page_tables); | |
2581 } | |
2582 | |
2583 void | |
2584 ggc_pch_read (FILE *f, void *addr) | |
2585 { | |
2586 struct ggc_pch_ondisk d; | |
2587 unsigned i; | |
2588 char *offs = (char *) addr; | |
2589 unsigned long count_old_page_tables; | |
2590 unsigned long count_new_page_tables; | |
2591 | |
2592 count_old_page_tables = G.by_depth_in_use; | |
2593 | |
145 | 2594 if (fread (&d, sizeof (d), 1, f) != 1) |
2595 fatal_error (input_location, "cannot read PCH file: %m"); | |
2596 | |
0 | 2597 /* We've just read in a PCH file. So, every object that used to be |
2598 allocated is now free. */ | |
2599 clear_marks (); | |
2600 #ifdef ENABLE_GC_CHECKING | |
2601 poison_pages (); | |
2602 #endif | |
2603 /* Since we free all the allocated objects, the free list becomes | |
2604 useless. Validate it now, which will also clear it. */ | |
111 | 2605 validate_free_objects (); |
0 | 2606 |
2607 /* No object read from a PCH file should ever be freed. So, set the | |
2608 context depth to 1, and set the depth of all the currently-allocated | |
2609 pages to be 1 too. PCH pages will have depth 0. */ | |
2610 gcc_assert (!G.context_depth); | |
2611 G.context_depth = 1; | |
111 | 2612 /* Allocate space for the depth 1 finalizers. */ |
2613 G.finalizers.safe_push (vNULL); | |
2614 G.vec_finalizers.safe_push (vNULL); | |
2615 gcc_assert (G.finalizers.length() == 2); | |
0 | 2616 for (i = 0; i < NUM_ORDERS; i++) |
2617 { | |
2618 page_entry *p; | |
2619 for (p = G.pages[i]; p != NULL; p = p->next) | |
2620 p->context_depth = G.context_depth; | |
2621 } | |
2622 | |
2623 /* Allocate the appropriate page-table entries for the pages read from | |
2624 the PCH file. */ | |
2625 | |
2626 for (i = 0; i < NUM_ORDERS; i++) | |
2627 { | |
2628 struct page_entry *entry; | |
2629 char *pte; | |
2630 size_t bytes; | |
2631 size_t num_objs; | |
2632 size_t j; | |
2633 | |
2634 if (d.totals[i] == 0) | |
2635 continue; | |
2636 | |
111 | 2637 bytes = PAGE_ALIGN (d.totals[i] * OBJECT_SIZE (i)); |
0 | 2638 num_objs = bytes / OBJECT_SIZE (i); |
2639 entry = XCNEWVAR (struct page_entry, (sizeof (struct page_entry) | |
2640 - sizeof (long) | |
2641 + BITMAP_SIZE (num_objs + 1))); | |
2642 entry->bytes = bytes; | |
2643 entry->page = offs; | |
2644 entry->context_depth = 0; | |
2645 offs += bytes; | |
2646 entry->num_free_objects = 0; | |
2647 entry->order = i; | |
2648 | |
2649 for (j = 0; | |
2650 j + HOST_BITS_PER_LONG <= num_objs + 1; | |
2651 j += HOST_BITS_PER_LONG) | |
2652 entry->in_use_p[j / HOST_BITS_PER_LONG] = -1; | |
2653 for (; j < num_objs + 1; j++) | |
2654 entry->in_use_p[j / HOST_BITS_PER_LONG] | |
2655 |= 1L << (j % HOST_BITS_PER_LONG); | |
2656 | |
2657 for (pte = entry->page; | |
2658 pte < entry->page + entry->bytes; | |
2659 pte += G.pagesize) | |
2660 set_page_table_entry (pte, entry); | |
2661 | |
2662 if (G.page_tails[i] != NULL) | |
2663 G.page_tails[i]->next = entry; | |
2664 else | |
2665 G.pages[i] = entry; | |
2666 G.page_tails[i] = entry; | |
2667 | |
2668 /* We start off by just adding all the new information to the | |
2669 end of the varrays, later, we will move the new information | |
2670 to the front of the varrays, as the PCH page tables are at | |
2671 context 0. */ | |
2672 push_by_depth (entry, 0); | |
2673 } | |
2674 | |
2675 /* Now, we update the various data structures that speed page table | |
2676 handling. */ | |
2677 count_new_page_tables = G.by_depth_in_use - count_old_page_tables; | |
2678 | |
2679 move_ptes_to_front (count_old_page_tables, count_new_page_tables); | |
2680 | |
2681 /* Update the statistics. */ | |
2682 G.allocated = G.allocated_last_gc = offs - (char *)addr; | |
2683 } |