Commit | Line | Data |
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177c0ea7 | 1 | /* Block-relocating memory allocator. |
ab422c4d | 2 | Copyright (C) 1993, 1995, 2000-2013 Free Software Foundation, Inc. |
dcfdbac7 JB |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
dcfdbac7 | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
dcfdbac7 JB |
10 | |
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
dcfdbac7 JB |
18 | |
19 | /* NOTES: | |
20 | ||
eb8c3be9 | 21 | Only relocate the blocs necessary for SIZE in r_alloc_sbrk, |
dcfdbac7 | 22 | rather than all of them. This means allowing for a possible |
abe9ff32 | 23 | hole between the first bloc and the end of malloc storage. */ |
dcfdbac7 | 24 | |
2c46d29f | 25 | #ifdef emacs |
aef4d570 | 26 | |
18160b98 | 27 | #include <config.h> |
0328b6de | 28 | |
956ace37 | 29 | #include "lisp.h" /* Needed for VALBITS. */ |
a4766fd5 | 30 | #include "blockinput.h" |
0a58f946 | 31 | |
642a1733 | 32 | #include <unistd.h> |
a8c0e5ea | 33 | |
b0119c68 | 34 | #ifdef DOUG_LEA_MALLOC |
177c0ea7 | 35 | #define M_TOP_PAD -2 |
971de7fb | 36 | extern int mallopt (int, int); |
0a58f946 | 37 | #else /* not DOUG_LEA_MALLOC */ |
a2c23c92 | 38 | #ifndef SYSTEM_MALLOC |
b1685c5f | 39 | extern size_t __malloc_extra_blocks; |
a2c23c92 | 40 | #endif /* SYSTEM_MALLOC */ |
0a58f946 | 41 | #endif /* not DOUG_LEA_MALLOC */ |
49081834 | 42 | |
d5179acc | 43 | #else /* not emacs */ |
aef4d570 | 44 | |
2c46d29f | 45 | #include <stddef.h> |
aef4d570 | 46 | #include <malloc.h> |
aef4d570 | 47 | |
d5179acc | 48 | #endif /* not emacs */ |
2c46d29f | 49 | |
0a58f946 | 50 | |
d5179acc | 51 | #include "getpagesize.h" |
dcfdbac7 | 52 | |
2c46d29f RS |
53 | /* A flag to indicate whether we have initialized ralloc yet. For |
54 | Emacs's sake, please do not make this local to malloc_init; on some | |
55 | machines, the dumping procedure makes all static variables | |
56 | read-only. On these machines, the word static is #defined to be | |
57 | the empty string, meaning that r_alloc_initialized becomes an | |
0a58f946 GM |
58 | automatic variable, and loses its value each time Emacs is started |
59 | up. */ | |
60 | ||
2c46d29f RS |
61 | static int r_alloc_initialized = 0; |
62 | ||
971de7fb | 63 | static void r_alloc_init (void); |
0a58f946 | 64 | |
dcfdbac7 | 65 | \f |
956ace37 JB |
66 | /* Declarations for working with the malloc, ralloc, and system breaks. */ |
67 | ||
abe9ff32 | 68 | /* Function to set the real break value. */ |
fcee5028 | 69 | void *(*real_morecore) (ptrdiff_t); |
dcfdbac7 | 70 | |
abe9ff32 | 71 | /* The break value, as seen by malloc. */ |
fcee5028 | 72 | static void *virtual_break_value; |
dcfdbac7 | 73 | |
abe9ff32 RS |
74 | /* The address of the end of the last data in use by ralloc, |
75 | including relocatable blocs as well as malloc data. */ | |
fcee5028 | 76 | static void *break_value; |
dcfdbac7 | 77 | |
7516b7d5 RS |
78 | /* This is the size of a page. We round memory requests to this boundary. */ |
79 | static int page_size; | |
80 | ||
177c0ea7 | 81 | /* Whenever we get memory from the system, get this many extra bytes. This |
ad3bb3d2 | 82 | must be a multiple of page_size. */ |
7516b7d5 RS |
83 | static int extra_bytes; |
84 | ||
dcfdbac7 | 85 | /* Macros for rounding. Note that rounding to any value is possible |
abe9ff32 | 86 | by changing the definition of PAGE. */ |
dcfdbac7 | 87 | #define PAGE (getpagesize ()) |
62aba0d4 | 88 | #define ROUNDUP(size) (((size_t) (size) + page_size - 1) \ |
fcee5028 | 89 | & ~((size_t) (page_size - 1))) |
e429caa2 | 90 | |
5e617bc2 | 91 | #define MEM_ALIGN sizeof (double) |
fcee5028 | 92 | #define MEM_ROUNDUP(addr) (((size_t) (addr) + MEM_ALIGN - 1) \ |
2d7d1608 | 93 | & ~(MEM_ALIGN - 1)) |
0a58f946 | 94 | |
aeac019e GM |
95 | /* The hook `malloc' uses for the function which gets more space |
96 | from the system. */ | |
97 | ||
98 | #ifndef SYSTEM_MALLOC | |
fcee5028 | 99 | extern void *(*__morecore) (ptrdiff_t); |
aeac019e GM |
100 | #endif |
101 | ||
102 | ||
e429caa2 | 103 | \f |
0a58f946 GM |
104 | /*********************************************************************** |
105 | Implementation using sbrk | |
106 | ***********************************************************************/ | |
107 | ||
abe9ff32 RS |
108 | /* Data structures of heaps and blocs. */ |
109 | ||
110 | /* The relocatable objects, or blocs, and the malloc data | |
111 | both reside within one or more heaps. | |
112 | Each heap contains malloc data, running from `start' to `bloc_start', | |
113 | and relocatable objects, running from `bloc_start' to `free'. | |
114 | ||
115 | Relocatable objects may relocate within the same heap | |
116 | or may move into another heap; the heaps themselves may grow | |
117 | but they never move. | |
118 | ||
119 | We try to make just one heap and make it larger as necessary. | |
8e6208c5 | 120 | But sometimes we can't do that, because we can't get contiguous |
abe9ff32 | 121 | space to add onto the heap. When that happens, we start a new heap. */ |
177c0ea7 | 122 | |
e429caa2 KH |
123 | typedef struct heap |
124 | { | |
125 | struct heap *next; | |
126 | struct heap *prev; | |
abe9ff32 | 127 | /* Start of memory range of this heap. */ |
fcee5028 | 128 | void *start; |
abe9ff32 | 129 | /* End of memory range of this heap. */ |
fcee5028 | 130 | void *end; |
abe9ff32 | 131 | /* Start of relocatable data in this heap. */ |
fcee5028 | 132 | void *bloc_start; |
abe9ff32 | 133 | /* Start of unused space in this heap. */ |
fcee5028 | 134 | void *free; |
47f13333 RS |
135 | /* First bloc in this heap. */ |
136 | struct bp *first_bloc; | |
137 | /* Last bloc in this heap. */ | |
138 | struct bp *last_bloc; | |
e429caa2 KH |
139 | } *heap_ptr; |
140 | ||
141 | #define NIL_HEAP ((heap_ptr) 0) | |
e429caa2 | 142 | |
abe9ff32 RS |
143 | /* This is the first heap object. |
144 | If we need additional heap objects, each one resides at the beginning of | |
145 | the space it covers. */ | |
146 | static struct heap heap_base; | |
147 | ||
148 | /* Head and tail of the list of heaps. */ | |
e429caa2 KH |
149 | static heap_ptr first_heap, last_heap; |
150 | ||
151 | /* These structures are allocated in the malloc arena. | |
152 | The linked list is kept in order of increasing '.data' members. | |
153 | The data blocks abut each other; if b->next is non-nil, then | |
177c0ea7 | 154 | b->data + b->size == b->next->data. |
49f82b3d | 155 | |
fcee5028 | 156 | An element with variable==NULL denotes a freed block, which has not yet |
f96f2c5b JB |
157 | been collected. They may only appear while r_alloc_freeze_level > 0, |
158 | and will be freed when the arena is thawed. Currently, these blocs are | |
159 | not reusable, while the arena is frozen. Very inefficient. */ | |
49f82b3d | 160 | |
e429caa2 KH |
161 | typedef struct bp |
162 | { | |
163 | struct bp *next; | |
164 | struct bp *prev; | |
fcee5028 PE |
165 | void **variable; |
166 | void *data; | |
167 | size_t size; | |
168 | void *new_data; /* temporarily used for relocation */ | |
49f82b3d | 169 | struct heap *heap; /* Heap this bloc is in. */ |
e429caa2 KH |
170 | } *bloc_ptr; |
171 | ||
172 | #define NIL_BLOC ((bloc_ptr) 0) | |
173 | #define BLOC_PTR_SIZE (sizeof (struct bp)) | |
174 | ||
abe9ff32 | 175 | /* Head and tail of the list of relocatable blocs. */ |
e429caa2 KH |
176 | static bloc_ptr first_bloc, last_bloc; |
177 | ||
49f82b3d RS |
178 | static int use_relocatable_buffers; |
179 | ||
180 | /* If >0, no relocation whatsoever takes place. */ | |
181 | static int r_alloc_freeze_level; | |
182 | ||
dcfdbac7 | 183 | \f |
956ace37 JB |
184 | /* Functions to get and return memory from the system. */ |
185 | ||
abe9ff32 RS |
186 | /* Find the heap that ADDRESS falls within. */ |
187 | ||
188 | static heap_ptr | |
fcee5028 | 189 | find_heap (void *address) |
abe9ff32 RS |
190 | { |
191 | heap_ptr heap; | |
192 | ||
193 | for (heap = last_heap; heap; heap = heap->prev) | |
194 | { | |
195 | if (heap->start <= address && address <= heap->end) | |
196 | return heap; | |
197 | } | |
198 | ||
199 | return NIL_HEAP; | |
200 | } | |
201 | ||
202 | /* Find SIZE bytes of space in a heap. | |
203 | Try to get them at ADDRESS (which must fall within some heap's range) | |
204 | if we can get that many within one heap. | |
205 | ||
e429caa2 | 206 | If enough space is not presently available in our reserve, this means |
8e6208c5 KH |
207 | getting more page-aligned space from the system. If the returned space |
208 | is not contiguous to the last heap, allocate a new heap, and append it | |
0d26e0b6 | 209 | to the heap list. |
abe9ff32 | 210 | |
0d26e0b6 JB |
211 | obtain does not try to keep track of whether space is in use or not |
212 | in use. It just returns the address of SIZE bytes that fall within a | |
213 | single heap. If you call obtain twice in a row with the same arguments, | |
214 | you typically get the same value. It's the caller's responsibility to | |
215 | keep track of what space is in use. | |
dcfdbac7 | 216 | |
e429caa2 KH |
217 | Return the address of the space if all went well, or zero if we couldn't |
218 | allocate the memory. */ | |
abe9ff32 | 219 | |
fcee5028 PE |
220 | static void * |
221 | obtain (void *address, size_t size) | |
dcfdbac7 | 222 | { |
e429caa2 | 223 | heap_ptr heap; |
fcee5028 | 224 | size_t already_available; |
dcfdbac7 | 225 | |
abe9ff32 | 226 | /* Find the heap that ADDRESS falls within. */ |
e429caa2 | 227 | for (heap = last_heap; heap; heap = heap->prev) |
dcfdbac7 | 228 | { |
e429caa2 KH |
229 | if (heap->start <= address && address <= heap->end) |
230 | break; | |
231 | } | |
dcfdbac7 | 232 | |
e429caa2 | 233 | if (! heap) |
1088b922 | 234 | emacs_abort (); |
dcfdbac7 | 235 | |
abe9ff32 RS |
236 | /* If we can't fit SIZE bytes in that heap, |
237 | try successive later heaps. */ | |
91a211b5 | 238 | while (heap && (char *) address + size > (char *) heap->end) |
e429caa2 KH |
239 | { |
240 | heap = heap->next; | |
241 | if (heap == NIL_HEAP) | |
242 | break; | |
243 | address = heap->bloc_start; | |
dcfdbac7 JB |
244 | } |
245 | ||
abe9ff32 RS |
246 | /* If we can't fit them within any existing heap, |
247 | get more space. */ | |
e429caa2 KH |
248 | if (heap == NIL_HEAP) |
249 | { | |
fcee5028 PE |
250 | void *new = real_morecore (0); |
251 | size_t get; | |
98b7fe02 | 252 | |
fcee5028 | 253 | already_available = (char *) last_heap->end - (char *) address; |
dcfdbac7 | 254 | |
e429caa2 KH |
255 | if (new != last_heap->end) |
256 | { | |
abe9ff32 RS |
257 | /* Someone else called sbrk. Make a new heap. */ |
258 | ||
259 | heap_ptr new_heap = (heap_ptr) MEM_ROUNDUP (new); | |
fcee5028 | 260 | void *bloc_start = (void *) MEM_ROUNDUP ((void *) (new_heap + 1)); |
e429caa2 | 261 | |
fcee5028 | 262 | if (real_morecore ((char *) bloc_start - (char *) new) != new) |
e429caa2 KH |
263 | return 0; |
264 | ||
265 | new_heap->start = new; | |
266 | new_heap->end = bloc_start; | |
267 | new_heap->bloc_start = bloc_start; | |
abe9ff32 | 268 | new_heap->free = bloc_start; |
e429caa2 KH |
269 | new_heap->next = NIL_HEAP; |
270 | new_heap->prev = last_heap; | |
47f13333 RS |
271 | new_heap->first_bloc = NIL_BLOC; |
272 | new_heap->last_bloc = NIL_BLOC; | |
e429caa2 KH |
273 | last_heap->next = new_heap; |
274 | last_heap = new_heap; | |
275 | ||
276 | address = bloc_start; | |
277 | already_available = 0; | |
278 | } | |
dcfdbac7 | 279 | |
abe9ff32 RS |
280 | /* Add space to the last heap (which we may have just created). |
281 | Get some extra, so we can come here less often. */ | |
282 | ||
e429caa2 | 283 | get = size + extra_bytes - already_available; |
fcee5028 | 284 | get = (char *) ROUNDUP ((char *) last_heap->end + get) |
e429caa2 | 285 | - (char *) last_heap->end; |
dcfdbac7 | 286 | |
fcee5028 | 287 | if (real_morecore (get) != last_heap->end) |
e429caa2 KH |
288 | return 0; |
289 | ||
91a211b5 | 290 | last_heap->end = (char *) last_heap->end + get; |
e429caa2 KH |
291 | } |
292 | ||
293 | return address; | |
294 | } | |
dcfdbac7 | 295 | |
abe9ff32 RS |
296 | /* Return unused heap space to the system |
297 | if there is a lot of unused space now. | |
298 | This can make the last heap smaller; | |
299 | it can also eliminate the last heap entirely. */ | |
300 | ||
dcfdbac7 | 301 | static void |
971de7fb | 302 | relinquish (void) |
dcfdbac7 | 303 | { |
e429caa2 | 304 | register heap_ptr h; |
62aba0d4 | 305 | ptrdiff_t excess = 0; |
e429caa2 | 306 | |
abe9ff32 RS |
307 | /* Add the amount of space beyond break_value |
308 | in all heaps which have extend beyond break_value at all. */ | |
309 | ||
e429caa2 KH |
310 | for (h = last_heap; h && break_value < h->end; h = h->prev) |
311 | { | |
312 | excess += (char *) h->end - (char *) ((break_value < h->bloc_start) | |
313 | ? h->bloc_start : break_value); | |
314 | } | |
315 | ||
fcee5028 | 316 | if (excess > extra_bytes * 2 && real_morecore (0) == last_heap->end) |
dcfdbac7 | 317 | { |
7516b7d5 RS |
318 | /* Keep extra_bytes worth of empty space. |
319 | And don't free anything unless we can free at least extra_bytes. */ | |
e429caa2 | 320 | excess -= extra_bytes; |
dcfdbac7 | 321 | |
fcee5028 | 322 | if ((char *) last_heap->end - (char *) last_heap->bloc_start <= excess) |
e429caa2 | 323 | { |
508f51f5 EZ |
324 | heap_ptr lh_prev; |
325 | ||
98daa893 EZ |
326 | /* This heap should have no blocs in it. If it does, we |
327 | cannot return it to the system. */ | |
47f13333 RS |
328 | if (last_heap->first_bloc != NIL_BLOC |
329 | || last_heap->last_bloc != NIL_BLOC) | |
98daa893 | 330 | return; |
47f13333 | 331 | |
abe9ff32 | 332 | /* Return the last heap, with its header, to the system. */ |
fcee5028 | 333 | excess = (char *) last_heap->end - (char *) last_heap->start; |
508f51f5 EZ |
334 | lh_prev = last_heap->prev; |
335 | /* If the system doesn't want that much memory back, leave | |
336 | last_heap unaltered to reflect that. This can occur if | |
337 | break_value is still within the original data segment. */ | |
fcee5028 | 338 | if (real_morecore (- excess) != 0) |
508f51f5 EZ |
339 | { |
340 | last_heap = lh_prev; | |
341 | last_heap->next = NIL_HEAP; | |
342 | } | |
e429caa2 KH |
343 | } |
344 | else | |
345 | { | |
fcee5028 PE |
346 | excess = ((char *) last_heap->end |
347 | - (char *) ROUNDUP ((char *) last_heap->end - excess)); | |
508f51f5 EZ |
348 | /* If the system doesn't want that much memory back, leave |
349 | the end of the last heap unchanged to reflect that. This | |
350 | can occur if break_value is still within the original | |
351 | data segment. */ | |
fcee5028 | 352 | if (real_morecore (- excess) != 0) |
508f51f5 | 353 | last_heap->end = (char *) last_heap->end - excess; |
21532667 | 354 | } |
e429caa2 | 355 | } |
dcfdbac7 JB |
356 | } |
357 | \f | |
956ace37 JB |
358 | /* The meat - allocating, freeing, and relocating blocs. */ |
359 | ||
956ace37 | 360 | /* Find the bloc referenced by the address in PTR. Returns a pointer |
abe9ff32 | 361 | to that block. */ |
dcfdbac7 JB |
362 | |
363 | static bloc_ptr | |
fcee5028 | 364 | find_bloc (void **ptr) |
dcfdbac7 | 365 | { |
fcee5028 | 366 | bloc_ptr p = first_bloc; |
dcfdbac7 JB |
367 | |
368 | while (p != NIL_BLOC) | |
369 | { | |
747d9d14 | 370 | /* Consistency check. Don't return inconsistent blocs. |
0d26e0b6 | 371 | Don't abort here, as callers might be expecting this, but |
747d9d14 JR |
372 | callers that always expect a bloc to be returned should abort |
373 | if one isn't to avoid a memory corruption bug that is | |
374 | difficult to track down. */ | |
dcfdbac7 JB |
375 | if (p->variable == ptr && p->data == *ptr) |
376 | return p; | |
377 | ||
378 | p = p->next; | |
379 | } | |
380 | ||
381 | return p; | |
382 | } | |
383 | ||
384 | /* Allocate a bloc of SIZE bytes and append it to the chain of blocs. | |
98b7fe02 JB |
385 | Returns a pointer to the new bloc, or zero if we couldn't allocate |
386 | memory for the new block. */ | |
dcfdbac7 JB |
387 | |
388 | static bloc_ptr | |
fcee5028 | 389 | get_bloc (size_t size) |
dcfdbac7 | 390 | { |
fcee5028 PE |
391 | bloc_ptr new_bloc; |
392 | heap_ptr heap; | |
98b7fe02 | 393 | |
38182d90 | 394 | if (! (new_bloc = malloc (BLOC_PTR_SIZE)) |
e429caa2 | 395 | || ! (new_bloc->data = obtain (break_value, size))) |
98b7fe02 | 396 | { |
c2cd06e6 | 397 | free (new_bloc); |
98b7fe02 JB |
398 | |
399 | return 0; | |
400 | } | |
dcfdbac7 | 401 | |
91a211b5 | 402 | break_value = (char *) new_bloc->data + size; |
e429caa2 | 403 | |
dcfdbac7 JB |
404 | new_bloc->size = size; |
405 | new_bloc->next = NIL_BLOC; | |
fcee5028 | 406 | new_bloc->variable = NULL; |
e429caa2 | 407 | new_bloc->new_data = 0; |
dcfdbac7 | 408 | |
abe9ff32 RS |
409 | /* Record in the heap that this space is in use. */ |
410 | heap = find_heap (new_bloc->data); | |
411 | heap->free = break_value; | |
412 | ||
47f13333 RS |
413 | /* Maintain the correspondence between heaps and blocs. */ |
414 | new_bloc->heap = heap; | |
415 | heap->last_bloc = new_bloc; | |
416 | if (heap->first_bloc == NIL_BLOC) | |
417 | heap->first_bloc = new_bloc; | |
418 | ||
abe9ff32 | 419 | /* Put this bloc on the doubly-linked list of blocs. */ |
dcfdbac7 JB |
420 | if (first_bloc) |
421 | { | |
422 | new_bloc->prev = last_bloc; | |
423 | last_bloc->next = new_bloc; | |
424 | last_bloc = new_bloc; | |
425 | } | |
426 | else | |
427 | { | |
428 | first_bloc = last_bloc = new_bloc; | |
429 | new_bloc->prev = NIL_BLOC; | |
430 | } | |
431 | ||
432 | return new_bloc; | |
433 | } | |
47f13333 | 434 | \f |
abe9ff32 RS |
435 | /* Calculate new locations of blocs in the list beginning with BLOC, |
436 | relocating it to start at ADDRESS, in heap HEAP. If enough space is | |
437 | not presently available in our reserve, call obtain for | |
177c0ea7 JB |
438 | more space. |
439 | ||
abe9ff32 RS |
440 | Store the new location of each bloc in its new_data field. |
441 | Do not touch the contents of blocs or break_value. */ | |
dcfdbac7 | 442 | |
e429caa2 | 443 | static int |
fcee5028 | 444 | relocate_blocs (bloc_ptr bloc, heap_ptr heap, void *address) |
e429caa2 | 445 | { |
fcee5028 | 446 | bloc_ptr b = bloc; |
ad3bb3d2 | 447 | |
49f82b3d | 448 | /* No need to ever call this if arena is frozen, bug somewhere! */ |
177c0ea7 | 449 | if (r_alloc_freeze_level) |
1088b922 | 450 | emacs_abort (); |
49f82b3d | 451 | |
e429caa2 KH |
452 | while (b) |
453 | { | |
abe9ff32 RS |
454 | /* If bloc B won't fit within HEAP, |
455 | move to the next heap and try again. */ | |
91a211b5 | 456 | while (heap && (char *) address + b->size > (char *) heap->end) |
e429caa2 KH |
457 | { |
458 | heap = heap->next; | |
459 | if (heap == NIL_HEAP) | |
460 | break; | |
461 | address = heap->bloc_start; | |
462 | } | |
dcfdbac7 | 463 | |
abe9ff32 RS |
464 | /* If BLOC won't fit in any heap, |
465 | get enough new space to hold BLOC and all following blocs. */ | |
e429caa2 KH |
466 | if (heap == NIL_HEAP) |
467 | { | |
fcee5028 PE |
468 | bloc_ptr tb = b; |
469 | size_t s = 0; | |
e429caa2 | 470 | |
abe9ff32 | 471 | /* Add up the size of all the following blocs. */ |
e429caa2 KH |
472 | while (tb != NIL_BLOC) |
473 | { | |
177c0ea7 | 474 | if (tb->variable) |
49f82b3d RS |
475 | s += tb->size; |
476 | ||
e429caa2 KH |
477 | tb = tb->next; |
478 | } | |
479 | ||
abe9ff32 RS |
480 | /* Get that space. */ |
481 | address = obtain (address, s); | |
482 | if (address == 0) | |
e429caa2 KH |
483 | return 0; |
484 | ||
485 | heap = last_heap; | |
486 | } | |
487 | ||
abe9ff32 RS |
488 | /* Record the new address of this bloc |
489 | and update where the next bloc can start. */ | |
e429caa2 | 490 | b->new_data = address; |
177c0ea7 | 491 | if (b->variable) |
91a211b5 | 492 | address = (char *) address + b->size; |
e429caa2 KH |
493 | b = b->next; |
494 | } | |
495 | ||
496 | return 1; | |
497 | } | |
47f13333 RS |
498 | \f |
499 | /* Update the records of which heaps contain which blocs, starting | |
500 | with heap HEAP and bloc BLOC. */ | |
501 | ||
502 | static void | |
971de7fb | 503 | update_heap_bloc_correspondence (bloc_ptr bloc, heap_ptr heap) |
abe9ff32 RS |
504 | { |
505 | register bloc_ptr b; | |
506 | ||
47f13333 RS |
507 | /* Initialize HEAP's status to reflect blocs before BLOC. */ |
508 | if (bloc != NIL_BLOC && bloc->prev != NIL_BLOC && bloc->prev->heap == heap) | |
509 | { | |
510 | /* The previous bloc is in HEAP. */ | |
511 | heap->last_bloc = bloc->prev; | |
91a211b5 | 512 | heap->free = (char *) bloc->prev->data + bloc->prev->size; |
47f13333 RS |
513 | } |
514 | else | |
515 | { | |
516 | /* HEAP contains no blocs before BLOC. */ | |
517 | heap->first_bloc = NIL_BLOC; | |
518 | heap->last_bloc = NIL_BLOC; | |
519 | heap->free = heap->bloc_start; | |
520 | } | |
521 | ||
abe9ff32 RS |
522 | /* Advance through blocs one by one. */ |
523 | for (b = bloc; b != NIL_BLOC; b = b->next) | |
524 | { | |
47f13333 RS |
525 | /* Advance through heaps, marking them empty, |
526 | till we get to the one that B is in. */ | |
abe9ff32 RS |
527 | while (heap) |
528 | { | |
529 | if (heap->bloc_start <= b->data && b->data <= heap->end) | |
530 | break; | |
531 | heap = heap->next; | |
47f13333 RS |
532 | /* We know HEAP is not null now, |
533 | because there has to be space for bloc B. */ | |
534 | heap->first_bloc = NIL_BLOC; | |
535 | heap->last_bloc = NIL_BLOC; | |
abe9ff32 RS |
536 | heap->free = heap->bloc_start; |
537 | } | |
47f13333 RS |
538 | |
539 | /* Update HEAP's status for bloc B. */ | |
91a211b5 | 540 | heap->free = (char *) b->data + b->size; |
47f13333 RS |
541 | heap->last_bloc = b; |
542 | if (heap->first_bloc == NIL_BLOC) | |
543 | heap->first_bloc = b; | |
544 | ||
545 | /* Record that B is in HEAP. */ | |
546 | b->heap = heap; | |
abe9ff32 RS |
547 | } |
548 | ||
549 | /* If there are any remaining heaps and no blocs left, | |
47f13333 | 550 | mark those heaps as empty. */ |
abe9ff32 RS |
551 | heap = heap->next; |
552 | while (heap) | |
553 | { | |
47f13333 RS |
554 | heap->first_bloc = NIL_BLOC; |
555 | heap->last_bloc = NIL_BLOC; | |
abe9ff32 RS |
556 | heap->free = heap->bloc_start; |
557 | heap = heap->next; | |
558 | } | |
559 | } | |
47f13333 | 560 | \f |
abe9ff32 RS |
561 | /* Resize BLOC to SIZE bytes. This relocates the blocs |
562 | that come after BLOC in memory. */ | |
563 | ||
e429caa2 | 564 | static int |
fcee5028 | 565 | resize_bloc (bloc_ptr bloc, size_t size) |
dcfdbac7 | 566 | { |
fcee5028 | 567 | bloc_ptr b; |
e429caa2 | 568 | heap_ptr heap; |
fcee5028 PE |
569 | void *address; |
570 | size_t old_size; | |
e429caa2 | 571 | |
49f82b3d | 572 | /* No need to ever call this if arena is frozen, bug somewhere! */ |
177c0ea7 | 573 | if (r_alloc_freeze_level) |
1088b922 | 574 | emacs_abort (); |
49f82b3d | 575 | |
e429caa2 KH |
576 | if (bloc == NIL_BLOC || size == bloc->size) |
577 | return 1; | |
578 | ||
579 | for (heap = first_heap; heap != NIL_HEAP; heap = heap->next) | |
580 | { | |
581 | if (heap->bloc_start <= bloc->data && bloc->data <= heap->end) | |
582 | break; | |
583 | } | |
584 | ||
585 | if (heap == NIL_HEAP) | |
1088b922 | 586 | emacs_abort (); |
e429caa2 KH |
587 | |
588 | old_size = bloc->size; | |
589 | bloc->size = size; | |
590 | ||
abe9ff32 | 591 | /* Note that bloc could be moved into the previous heap. */ |
91a211b5 GM |
592 | address = (bloc->prev ? (char *) bloc->prev->data + bloc->prev->size |
593 | : (char *) first_heap->bloc_start); | |
e429caa2 KH |
594 | while (heap) |
595 | { | |
596 | if (heap->bloc_start <= address && address <= heap->end) | |
597 | break; | |
598 | heap = heap->prev; | |
599 | } | |
600 | ||
601 | if (! relocate_blocs (bloc, heap, address)) | |
602 | { | |
603 | bloc->size = old_size; | |
604 | return 0; | |
605 | } | |
606 | ||
607 | if (size > old_size) | |
608 | { | |
609 | for (b = last_bloc; b != bloc; b = b->prev) | |
610 | { | |
49f82b3d RS |
611 | if (!b->variable) |
612 | { | |
613 | b->size = 0; | |
614 | b->data = b->new_data; | |
177c0ea7 JB |
615 | } |
616 | else | |
49f82b3d | 617 | { |
78cef877 EZ |
618 | if (b->new_data != b->data) |
619 | memmove (b->new_data, b->data, b->size); | |
49f82b3d RS |
620 | *b->variable = b->data = b->new_data; |
621 | } | |
622 | } | |
623 | if (!bloc->variable) | |
624 | { | |
625 | bloc->size = 0; | |
626 | bloc->data = bloc->new_data; | |
627 | } | |
628 | else | |
629 | { | |
78cef877 EZ |
630 | if (bloc->new_data != bloc->data) |
631 | memmove (bloc->new_data, bloc->data, old_size); | |
3ce2f8ac | 632 | memset ((char *) bloc->new_data + old_size, 0, size - old_size); |
49f82b3d | 633 | *bloc->variable = bloc->data = bloc->new_data; |
e429caa2 | 634 | } |
e429caa2 KH |
635 | } |
636 | else | |
dcfdbac7 | 637 | { |
ad3bb3d2 JB |
638 | for (b = bloc; b != NIL_BLOC; b = b->next) |
639 | { | |
49f82b3d RS |
640 | if (!b->variable) |
641 | { | |
642 | b->size = 0; | |
643 | b->data = b->new_data; | |
177c0ea7 JB |
644 | } |
645 | else | |
49f82b3d | 646 | { |
78cef877 EZ |
647 | if (b->new_data != b->data) |
648 | memmove (b->new_data, b->data, b->size); | |
49f82b3d RS |
649 | *b->variable = b->data = b->new_data; |
650 | } | |
ad3bb3d2 | 651 | } |
ad3bb3d2 | 652 | } |
dcfdbac7 | 653 | |
47f13333 | 654 | update_heap_bloc_correspondence (bloc, heap); |
abe9ff32 | 655 | |
91a211b5 GM |
656 | break_value = (last_bloc ? (char *) last_bloc->data + last_bloc->size |
657 | : (char *) first_heap->bloc_start); | |
e429caa2 KH |
658 | return 1; |
659 | } | |
47f13333 | 660 | \f |
abe9ff32 RS |
661 | /* Free BLOC from the chain of blocs, relocating any blocs above it. |
662 | This may return space to the system. */ | |
dcfdbac7 JB |
663 | |
664 | static void | |
971de7fb | 665 | free_bloc (bloc_ptr bloc) |
dcfdbac7 | 666 | { |
47f13333 | 667 | heap_ptr heap = bloc->heap; |
36c46f8e | 668 | heap_ptr h; |
47f13333 | 669 | |
49f82b3d RS |
670 | if (r_alloc_freeze_level) |
671 | { | |
fcee5028 | 672 | bloc->variable = NULL; |
49f82b3d RS |
673 | return; |
674 | } | |
177c0ea7 | 675 | |
e429caa2 KH |
676 | resize_bloc (bloc, 0); |
677 | ||
dcfdbac7 JB |
678 | if (bloc == first_bloc && bloc == last_bloc) |
679 | { | |
680 | first_bloc = last_bloc = NIL_BLOC; | |
681 | } | |
682 | else if (bloc == last_bloc) | |
683 | { | |
684 | last_bloc = bloc->prev; | |
685 | last_bloc->next = NIL_BLOC; | |
686 | } | |
687 | else if (bloc == first_bloc) | |
688 | { | |
689 | first_bloc = bloc->next; | |
690 | first_bloc->prev = NIL_BLOC; | |
dcfdbac7 JB |
691 | } |
692 | else | |
693 | { | |
694 | bloc->next->prev = bloc->prev; | |
695 | bloc->prev->next = bloc->next; | |
dcfdbac7 JB |
696 | } |
697 | ||
36c46f8e EZ |
698 | /* Sometimes, 'heap' obtained from bloc->heap above is not really a |
699 | 'heap' structure. It can even be beyond the current break point, | |
700 | which will cause crashes when we dereference it below (see | |
701 | bug#12242). Evidently, the reason is bloc allocations done while | |
702 | use_relocatable_buffers was non-positive, because additional | |
703 | memory we get then is not recorded in the heaps we manage. If | |
704 | bloc->heap records such a "heap", we cannot (and don't need to) | |
705 | update its records. So we validate the 'heap' value by making | |
706 | sure it is one of the heaps we manage via the heaps linked list, | |
707 | and don't touch a 'heap' that isn't found there. This avoids | |
708 | accessing memory we know nothing about. */ | |
709 | for (h = first_heap; h != NIL_HEAP; h = h->next) | |
710 | if (heap == h) | |
711 | break; | |
712 | ||
713 | if (h) | |
47f13333 | 714 | { |
36c46f8e EZ |
715 | /* Update the records of which blocs are in HEAP. */ |
716 | if (heap->first_bloc == bloc) | |
717 | { | |
718 | if (bloc->next != 0 && bloc->next->heap == heap) | |
719 | heap->first_bloc = bloc->next; | |
720 | else | |
721 | heap->first_bloc = heap->last_bloc = NIL_BLOC; | |
722 | } | |
723 | if (heap->last_bloc == bloc) | |
724 | { | |
725 | if (bloc->prev != 0 && bloc->prev->heap == heap) | |
726 | heap->last_bloc = bloc->prev; | |
727 | else | |
728 | heap->first_bloc = heap->last_bloc = NIL_BLOC; | |
729 | } | |
47f13333 RS |
730 | } |
731 | ||
e429caa2 | 732 | relinquish (); |
dcfdbac7 JB |
733 | free (bloc); |
734 | } | |
735 | \f | |
956ace37 JB |
736 | /* Interface routines. */ |
737 | ||
98b7fe02 | 738 | /* Obtain SIZE bytes of storage from the free pool, or the system, as |
2c46d29f | 739 | necessary. If relocatable blocs are in use, this means relocating |
98b7fe02 JB |
740 | them. This function gets plugged into the GNU malloc's __morecore |
741 | hook. | |
742 | ||
7516b7d5 RS |
743 | We provide hysteresis, never relocating by less than extra_bytes. |
744 | ||
98b7fe02 JB |
745 | If we're out of memory, we should return zero, to imitate the other |
746 | __morecore hook values - in particular, __default_morecore in the | |
747 | GNU malloc package. */ | |
dcfdbac7 | 748 | |
fcee5028 | 749 | static void * |
62aba0d4 | 750 | r_alloc_sbrk (ptrdiff_t size) |
dcfdbac7 | 751 | { |
fcee5028 PE |
752 | bloc_ptr b; |
753 | void *address; | |
dcfdbac7 | 754 | |
44d3dec0 RS |
755 | if (! r_alloc_initialized) |
756 | r_alloc_init (); | |
757 | ||
e8a02204 | 758 | if (use_relocatable_buffers <= 0) |
fcee5028 | 759 | return real_morecore (size); |
dcfdbac7 | 760 | |
e429caa2 KH |
761 | if (size == 0) |
762 | return virtual_break_value; | |
7516b7d5 | 763 | |
e429caa2 | 764 | if (size > 0) |
dcfdbac7 | 765 | { |
abe9ff32 RS |
766 | /* Allocate a page-aligned space. GNU malloc would reclaim an |
767 | extra space if we passed an unaligned one. But we could | |
8e6208c5 | 768 | not always find a space which is contiguous to the previous. */ |
fcee5028 | 769 | void *new_bloc_start; |
e429caa2 | 770 | heap_ptr h = first_heap; |
fcee5028 | 771 | size_t get = ROUNDUP (size); |
7516b7d5 | 772 | |
fcee5028 | 773 | address = (void *) ROUNDUP (virtual_break_value); |
e429caa2 | 774 | |
abe9ff32 | 775 | /* Search the list upward for a heap which is large enough. */ |
fcee5028 | 776 | while ((char *) h->end < (char *) MEM_ROUNDUP ((char *) address + get)) |
e429caa2 KH |
777 | { |
778 | h = h->next; | |
779 | if (h == NIL_HEAP) | |
780 | break; | |
fcee5028 | 781 | address = (void *) ROUNDUP (h->start); |
e429caa2 KH |
782 | } |
783 | ||
abe9ff32 | 784 | /* If not found, obtain more space. */ |
e429caa2 KH |
785 | if (h == NIL_HEAP) |
786 | { | |
787 | get += extra_bytes + page_size; | |
788 | ||
49f82b3d | 789 | if (! obtain (address, get)) |
e429caa2 | 790 | return 0; |
98b7fe02 | 791 | |
e429caa2 | 792 | if (first_heap == last_heap) |
fcee5028 | 793 | address = (void *) ROUNDUP (virtual_break_value); |
e429caa2 | 794 | else |
fcee5028 | 795 | address = (void *) ROUNDUP (last_heap->start); |
e429caa2 KH |
796 | h = last_heap; |
797 | } | |
798 | ||
fcee5028 | 799 | new_bloc_start = (void *) MEM_ROUNDUP ((char *) address + get); |
e429caa2 KH |
800 | |
801 | if (first_heap->bloc_start < new_bloc_start) | |
802 | { | |
49f82b3d | 803 | /* This is no clean solution - no idea how to do it better. */ |
177c0ea7 | 804 | if (r_alloc_freeze_level) |
fcee5028 | 805 | return NULL; |
49f82b3d RS |
806 | |
807 | /* There is a bug here: if the above obtain call succeeded, but the | |
808 | relocate_blocs call below does not succeed, we need to free | |
809 | the memory that we got with obtain. */ | |
810 | ||
abe9ff32 | 811 | /* Move all blocs upward. */ |
49f82b3d | 812 | if (! relocate_blocs (first_bloc, h, new_bloc_start)) |
e429caa2 KH |
813 | return 0; |
814 | ||
fcee5028 | 815 | /* Note that (char *) (h + 1) <= (char *) new_bloc_start since |
e429caa2 | 816 | get >= page_size, so the following does not destroy the heap |
abe9ff32 | 817 | header. */ |
e429caa2 KH |
818 | for (b = last_bloc; b != NIL_BLOC; b = b->prev) |
819 | { | |
78cef877 EZ |
820 | if (b->new_data != b->data) |
821 | memmove (b->new_data, b->data, b->size); | |
e429caa2 KH |
822 | *b->variable = b->data = b->new_data; |
823 | } | |
824 | ||
825 | h->bloc_start = new_bloc_start; | |
abe9ff32 | 826 | |
47f13333 | 827 | update_heap_bloc_correspondence (first_bloc, h); |
e429caa2 | 828 | } |
e429caa2 KH |
829 | if (h != first_heap) |
830 | { | |
831 | /* Give up managing heaps below the one the new | |
abe9ff32 | 832 | virtual_break_value points to. */ |
e429caa2 KH |
833 | first_heap->prev = NIL_HEAP; |
834 | first_heap->next = h->next; | |
835 | first_heap->start = h->start; | |
836 | first_heap->end = h->end; | |
abe9ff32 | 837 | first_heap->free = h->free; |
47f13333 RS |
838 | first_heap->first_bloc = h->first_bloc; |
839 | first_heap->last_bloc = h->last_bloc; | |
e429caa2 KH |
840 | first_heap->bloc_start = h->bloc_start; |
841 | ||
842 | if (first_heap->next) | |
843 | first_heap->next->prev = first_heap; | |
844 | else | |
845 | last_heap = first_heap; | |
846 | } | |
847 | ||
72af86bd | 848 | memset (address, 0, size); |
dcfdbac7 | 849 | } |
e429caa2 | 850 | else /* size < 0 */ |
dcfdbac7 | 851 | { |
fcee5028 PE |
852 | size_t excess = ((char *) first_heap->bloc_start |
853 | - ((char *) virtual_break_value + size)); | |
e429caa2 KH |
854 | |
855 | address = virtual_break_value; | |
856 | ||
857 | if (r_alloc_freeze_level == 0 && excess > 2 * extra_bytes) | |
858 | { | |
859 | excess -= extra_bytes; | |
860 | first_heap->bloc_start | |
fcee5028 | 861 | = (void *) MEM_ROUNDUP ((char *) first_heap->bloc_start - excess); |
e429caa2 | 862 | |
abe9ff32 | 863 | relocate_blocs (first_bloc, first_heap, first_heap->bloc_start); |
7516b7d5 | 864 | |
e429caa2 KH |
865 | for (b = first_bloc; b != NIL_BLOC; b = b->next) |
866 | { | |
78cef877 EZ |
867 | if (b->new_data != b->data) |
868 | memmove (b->new_data, b->data, b->size); | |
e429caa2 KH |
869 | *b->variable = b->data = b->new_data; |
870 | } | |
871 | } | |
872 | ||
fcee5028 | 873 | if ((char *) virtual_break_value + size < (char *) first_heap->start) |
e429caa2 KH |
874 | { |
875 | /* We found an additional space below the first heap */ | |
fcee5028 | 876 | first_heap->start = (void *) ((char *) virtual_break_value + size); |
e429caa2 | 877 | } |
dcfdbac7 JB |
878 | } |
879 | ||
fcee5028 | 880 | virtual_break_value = (void *) ((char *) address + size); |
47f13333 | 881 | break_value = (last_bloc |
91a211b5 GM |
882 | ? (char *) last_bloc->data + last_bloc->size |
883 | : (char *) first_heap->bloc_start); | |
e429caa2 | 884 | if (size < 0) |
abe9ff32 | 885 | relinquish (); |
7516b7d5 | 886 | |
e429caa2 | 887 | return address; |
dcfdbac7 JB |
888 | } |
889 | ||
0a58f946 | 890 | |
dcfdbac7 JB |
891 | /* Allocate a relocatable bloc of storage of size SIZE. A pointer to |
892 | the data is returned in *PTR. PTR is thus the address of some variable | |
98b7fe02 JB |
893 | which will use the data area. |
894 | ||
49f82b3d | 895 | The allocation of 0 bytes is valid. |
f96f2c5b JB |
896 | In case r_alloc_freeze_level is set, a best fit of unused blocs could be |
897 | done before allocating a new area. Not yet done. | |
49f82b3d | 898 | |
98b7fe02 JB |
899 | If we can't allocate the necessary memory, set *PTR to zero, and |
900 | return zero. */ | |
dcfdbac7 | 901 | |
fcee5028 PE |
902 | void * |
903 | r_alloc (void **ptr, size_t size) | |
dcfdbac7 | 904 | { |
fcee5028 | 905 | bloc_ptr new_bloc; |
dcfdbac7 | 906 | |
2c46d29f RS |
907 | if (! r_alloc_initialized) |
908 | r_alloc_init (); | |
909 | ||
abe9ff32 | 910 | new_bloc = get_bloc (MEM_ROUNDUP (size)); |
98b7fe02 JB |
911 | if (new_bloc) |
912 | { | |
913 | new_bloc->variable = ptr; | |
914 | *ptr = new_bloc->data; | |
915 | } | |
916 | else | |
917 | *ptr = 0; | |
dcfdbac7 JB |
918 | |
919 | return *ptr; | |
920 | } | |
921 | ||
2c46d29f RS |
922 | /* Free a bloc of relocatable storage whose data is pointed to by PTR. |
923 | Store 0 in *PTR to show there's no block allocated. */ | |
dcfdbac7 JB |
924 | |
925 | void | |
fcee5028 | 926 | r_alloc_free (void **ptr) |
dcfdbac7 | 927 | { |
fcee5028 | 928 | bloc_ptr dead_bloc; |
dcfdbac7 | 929 | |
44d3dec0 RS |
930 | if (! r_alloc_initialized) |
931 | r_alloc_init (); | |
932 | ||
dcfdbac7 JB |
933 | dead_bloc = find_bloc (ptr); |
934 | if (dead_bloc == NIL_BLOC) | |
1088b922 | 935 | emacs_abort (); /* Double free? PTR not originally used to allocate? */ |
dcfdbac7 JB |
936 | |
937 | free_bloc (dead_bloc); | |
2c46d29f | 938 | *ptr = 0; |
719b242f | 939 | |
d5179acc | 940 | #ifdef emacs |
719b242f | 941 | refill_memory_reserve (); |
d5179acc | 942 | #endif |
dcfdbac7 JB |
943 | } |
944 | ||
16a5c729 | 945 | /* Given a pointer at address PTR to relocatable data, resize it to SIZE. |
98b7fe02 JB |
946 | Do this by shifting all blocks above this one up in memory, unless |
947 | SIZE is less than or equal to the current bloc size, in which case | |
948 | do nothing. | |
dcfdbac7 | 949 | |
f96f2c5b | 950 | In case r_alloc_freeze_level is set, a new bloc is allocated, and the |
8e6208c5 | 951 | memory copied to it. Not very efficient. We could traverse the |
49f82b3d RS |
952 | bloc_list for a best fit of free blocs first. |
953 | ||
98b7fe02 JB |
954 | Change *PTR to reflect the new bloc, and return this value. |
955 | ||
956 | If more memory cannot be allocated, then leave *PTR unchanged, and | |
957 | return zero. */ | |
dcfdbac7 | 958 | |
fcee5028 PE |
959 | void * |
960 | r_re_alloc (void **ptr, size_t size) | |
dcfdbac7 | 961 | { |
fcee5028 | 962 | bloc_ptr bloc; |
dcfdbac7 | 963 | |
44d3dec0 RS |
964 | if (! r_alloc_initialized) |
965 | r_alloc_init (); | |
966 | ||
49f82b3d RS |
967 | if (!*ptr) |
968 | return r_alloc (ptr, size); | |
177c0ea7 | 969 | if (!size) |
49f82b3d RS |
970 | { |
971 | r_alloc_free (ptr); | |
972 | return r_alloc (ptr, 0); | |
973 | } | |
974 | ||
16a5c729 JB |
975 | bloc = find_bloc (ptr); |
976 | if (bloc == NIL_BLOC) | |
1088b922 | 977 | emacs_abort (); /* Already freed? PTR not originally used to allocate? */ |
dcfdbac7 | 978 | |
177c0ea7 | 979 | if (size < bloc->size) |
49f82b3d RS |
980 | { |
981 | /* Wouldn't it be useful to actually resize the bloc here? */ | |
982 | /* I think so too, but not if it's too expensive... */ | |
177c0ea7 JB |
983 | if ((bloc->size - MEM_ROUNDUP (size) >= page_size) |
984 | && r_alloc_freeze_level == 0) | |
49f82b3d RS |
985 | { |
986 | resize_bloc (bloc, MEM_ROUNDUP (size)); | |
987 | /* Never mind if this fails, just do nothing... */ | |
988 | /* It *should* be infallible! */ | |
989 | } | |
990 | } | |
991 | else if (size > bloc->size) | |
992 | { | |
993 | if (r_alloc_freeze_level) | |
994 | { | |
995 | bloc_ptr new_bloc; | |
996 | new_bloc = get_bloc (MEM_ROUNDUP (size)); | |
997 | if (new_bloc) | |
998 | { | |
999 | new_bloc->variable = ptr; | |
1000 | *ptr = new_bloc->data; | |
fcee5028 | 1001 | bloc->variable = NULL; |
49f82b3d RS |
1002 | } |
1003 | else | |
fcee5028 | 1004 | return NULL; |
49f82b3d | 1005 | } |
177c0ea7 | 1006 | else |
49f82b3d RS |
1007 | { |
1008 | if (! resize_bloc (bloc, MEM_ROUNDUP (size))) | |
fcee5028 | 1009 | return NULL; |
49f82b3d RS |
1010 | } |
1011 | } | |
dcfdbac7 JB |
1012 | return *ptr; |
1013 | } | |
81bd58e8 | 1014 | |
dec41418 RS |
1015 | |
1016 | #if defined (emacs) && defined (DOUG_LEA_MALLOC) | |
1017 | ||
1018 | /* Reinitialize the morecore hook variables after restarting a dumped | |
1019 | Emacs. This is needed when using Doug Lea's malloc from GNU libc. */ | |
1020 | void | |
971de7fb | 1021 | r_alloc_reinit (void) |
dec41418 RS |
1022 | { |
1023 | /* Only do this if the hook has been reset, so that we don't get an | |
1024 | infinite loop, in case Emacs was linked statically. */ | |
1025 | if (__morecore != r_alloc_sbrk) | |
1026 | { | |
1027 | real_morecore = __morecore; | |
1028 | __morecore = r_alloc_sbrk; | |
1029 | } | |
1030 | } | |
0a58f946 GM |
1031 | |
1032 | #endif /* emacs && DOUG_LEA_MALLOC */ | |
dec41418 | 1033 | |
e429caa2 | 1034 | #ifdef DEBUG |
0a58f946 | 1035 | |
e429caa2 KH |
1036 | #include <assert.h> |
1037 | ||
44d3dec0 | 1038 | void |
268c2c36 | 1039 | r_alloc_check (void) |
e429caa2 | 1040 | { |
6d16dd06 RS |
1041 | int found = 0; |
1042 | heap_ptr h, ph = 0; | |
1043 | bloc_ptr b, pb = 0; | |
1044 | ||
1045 | if (!r_alloc_initialized) | |
1046 | return; | |
1047 | ||
1048 | assert (first_heap); | |
fcee5028 PE |
1049 | assert (last_heap->end <= (void *) sbrk (0)); |
1050 | assert ((void *) first_heap < first_heap->start); | |
6d16dd06 RS |
1051 | assert (first_heap->start <= virtual_break_value); |
1052 | assert (virtual_break_value <= first_heap->end); | |
1053 | ||
1054 | for (h = first_heap; h; h = h->next) | |
1055 | { | |
1056 | assert (h->prev == ph); | |
fcee5028 | 1057 | assert ((void *) ROUNDUP (h->end) == h->end); |
40f3f04b RS |
1058 | #if 0 /* ??? The code in ralloc.c does not really try to ensure |
1059 | the heap start has any sort of alignment. | |
1060 | Perhaps it should. */ | |
fcee5028 | 1061 | assert ((void *) MEM_ROUNDUP (h->start) == h->start); |
40f3f04b | 1062 | #endif |
fcee5028 | 1063 | assert ((void *) MEM_ROUNDUP (h->bloc_start) == h->bloc_start); |
6d16dd06 RS |
1064 | assert (h->start <= h->bloc_start && h->bloc_start <= h->end); |
1065 | ||
1066 | if (ph) | |
1067 | { | |
1068 | assert (ph->end < h->start); | |
fcee5028 | 1069 | assert (h->start <= (void *) h && (void *) (h + 1) <= h->bloc_start); |
6d16dd06 RS |
1070 | } |
1071 | ||
1072 | if (h->bloc_start <= break_value && break_value <= h->end) | |
1073 | found = 1; | |
1074 | ||
1075 | ph = h; | |
1076 | } | |
1077 | ||
1078 | assert (found); | |
1079 | assert (last_heap == ph); | |
1080 | ||
1081 | for (b = first_bloc; b; b = b->next) | |
1082 | { | |
1083 | assert (b->prev == pb); | |
fcee5028 PE |
1084 | assert ((void *) MEM_ROUNDUP (b->data) == b->data); |
1085 | assert ((size_t) MEM_ROUNDUP (b->size) == b->size); | |
6d16dd06 RS |
1086 | |
1087 | ph = 0; | |
1088 | for (h = first_heap; h; h = h->next) | |
1089 | { | |
1090 | if (h->bloc_start <= b->data && b->data + b->size <= h->end) | |
1091 | break; | |
1092 | ph = h; | |
1093 | } | |
1094 | ||
1095 | assert (h); | |
1096 | ||
1097 | if (pb && pb->data + pb->size != b->data) | |
1098 | { | |
1099 | assert (ph && b->data == h->bloc_start); | |
1100 | while (ph) | |
1101 | { | |
1102 | if (ph->bloc_start <= pb->data | |
1103 | && pb->data + pb->size <= ph->end) | |
1104 | { | |
1105 | assert (pb->data + pb->size + b->size > ph->end); | |
1106 | break; | |
1107 | } | |
1108 | else | |
1109 | { | |
1110 | assert (ph->bloc_start + b->size > ph->end); | |
1111 | } | |
1112 | ph = ph->prev; | |
1113 | } | |
1114 | } | |
1115 | pb = b; | |
1116 | } | |
1117 | ||
1118 | assert (last_bloc == pb); | |
1119 | ||
1120 | if (last_bloc) | |
1121 | assert (last_bloc->data + last_bloc->size == break_value); | |
1122 | else | |
1123 | assert (first_heap->bloc_start == break_value); | |
e429caa2 | 1124 | } |
0a58f946 | 1125 | |
e429caa2 | 1126 | #endif /* DEBUG */ |
0a58f946 | 1127 | |
baae5c2d JR |
1128 | /* Update the internal record of which variable points to some data to NEW. |
1129 | Used by buffer-swap-text in Emacs to restore consistency after it | |
1130 | swaps the buffer text between two buffer objects. The OLD pointer | |
1131 | is checked to ensure that memory corruption does not occur due to | |
1132 | misuse. */ | |
1133 | void | |
fcee5028 | 1134 | r_alloc_reset_variable (void **old, void **new) |
baae5c2d JR |
1135 | { |
1136 | bloc_ptr bloc = first_bloc; | |
1137 | ||
1138 | /* Find the bloc that corresponds to the data pointed to by pointer. | |
1139 | find_bloc cannot be used, as it has internal consistency checks | |
0d26e0b6 | 1140 | which fail when the variable needs resetting. */ |
baae5c2d JR |
1141 | while (bloc != NIL_BLOC) |
1142 | { | |
1143 | if (bloc->data == *new) | |
1144 | break; | |
1145 | ||
1146 | bloc = bloc->next; | |
1147 | } | |
1148 | ||
1149 | if (bloc == NIL_BLOC || bloc->variable != old) | |
1088b922 | 1150 | emacs_abort (); /* Already freed? OLD not originally used to allocate? */ |
baae5c2d JR |
1151 | |
1152 | /* Update variable to point to the new location. */ | |
1153 | bloc->variable = new; | |
1154 | } | |
0a58f946 | 1155 | |
52c55cc7 EZ |
1156 | void |
1157 | r_alloc_inhibit_buffer_relocation (int inhibit) | |
1158 | { | |
e8a02204 EZ |
1159 | if (use_relocatable_buffers > 1) |
1160 | use_relocatable_buffers = 1; | |
291d430f | 1161 | if (inhibit) |
291d430f | 1162 | use_relocatable_buffers--; |
e8a02204 EZ |
1163 | else if (use_relocatable_buffers < 1) |
1164 | use_relocatable_buffers++; | |
52c55cc7 EZ |
1165 | } |
1166 | ||
0a58f946 GM |
1167 | \f |
1168 | /*********************************************************************** | |
1169 | Initialization | |
1170 | ***********************************************************************/ | |
1171 | ||
0a58f946 GM |
1172 | /* Initialize various things for memory allocation. */ |
1173 | ||
1174 | static void | |
971de7fb | 1175 | r_alloc_init (void) |
0a58f946 GM |
1176 | { |
1177 | if (r_alloc_initialized) | |
1178 | return; | |
0a58f946 | 1179 | r_alloc_initialized = 1; |
177c0ea7 | 1180 | |
a2c23c92 DL |
1181 | page_size = PAGE; |
1182 | #ifndef SYSTEM_MALLOC | |
0a58f946 GM |
1183 | real_morecore = __morecore; |
1184 | __morecore = r_alloc_sbrk; | |
1185 | ||
1186 | first_heap = last_heap = &heap_base; | |
1187 | first_heap->next = first_heap->prev = NIL_HEAP; | |
1188 | first_heap->start = first_heap->bloc_start | |
fcee5028 PE |
1189 | = virtual_break_value = break_value = real_morecore (0); |
1190 | if (break_value == NULL) | |
1088b922 | 1191 | emacs_abort (); |
0a58f946 | 1192 | |
0a58f946 | 1193 | extra_bytes = ROUNDUP (50000); |
a2c23c92 | 1194 | #endif |
0a58f946 GM |
1195 | |
1196 | #ifdef DOUG_LEA_MALLOC | |
4d7e6e51 | 1197 | block_input (); |
1673df2e | 1198 | mallopt (M_TOP_PAD, 64 * 4096); |
4d7e6e51 | 1199 | unblock_input (); |
0a58f946 | 1200 | #else |
a2c23c92 | 1201 | #ifndef SYSTEM_MALLOC |
45ba16c7 EZ |
1202 | /* Give GNU malloc's morecore some hysteresis so that we move all |
1203 | the relocatable blocks much less often. The number used to be | |
1204 | 64, but alloc.c would override that with 32 in code that was | |
1205 | removed when SYNC_INPUT became the only input handling mode. | |
9b318728 | 1206 | That code was conditioned on !DOUG_LEA_MALLOC, so the call to |
45ba16c7 EZ |
1207 | mallopt above is left unchanged. (Actually, I think there's no |
1208 | system nowadays that uses DOUG_LEA_MALLOC and also uses | |
1209 | REL_ALLOC.) */ | |
1210 | __malloc_extra_blocks = 32; | |
0a58f946 | 1211 | #endif |
a2c23c92 | 1212 | #endif |
0a58f946 | 1213 | |
5ad25b24 | 1214 | #ifndef SYSTEM_MALLOC |
fcee5028 | 1215 | first_heap->end = (void *) ROUNDUP (first_heap->start); |
0a58f946 GM |
1216 | |
1217 | /* The extra call to real_morecore guarantees that the end of the | |
1218 | address space is a multiple of page_size, even if page_size is | |
1219 | not really the page size of the system running the binary in | |
1220 | which page_size is stored. This allows a binary to be built on a | |
1221 | system with one page size and run on a system with a smaller page | |
1222 | size. */ | |
fcee5028 | 1223 | real_morecore ((char *) first_heap->end - (char *) first_heap->start); |
0a58f946 GM |
1224 | |
1225 | /* Clear the rest of the last page; this memory is in our address space | |
1226 | even though it is after the sbrk value. */ | |
1227 | /* Doubly true, with the additional call that explicitly adds the | |
1228 | rest of that page to the address space. */ | |
72af86bd AS |
1229 | memset (first_heap->start, 0, |
1230 | (char *) first_heap->end - (char *) first_heap->start); | |
0a58f946 | 1231 | virtual_break_value = break_value = first_heap->bloc_start = first_heap->end; |
a2c23c92 | 1232 | #endif |
177c0ea7 | 1233 | |
0a58f946 GM |
1234 | use_relocatable_buffers = 1; |
1235 | } |