Commit | Line | Data |
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dcfdbac7 | 1 | /* Block-relocating memory allocator. |
187996a8 | 2 | Copyright (C) 1993, 1995 Free Software Foundation, Inc. |
dcfdbac7 JB |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
6 | GNU Emacs is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
187996a8 | 8 | the Free Software Foundation; either version 2, or (at your option) |
dcfdbac7 JB |
9 | any later version. |
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 | |
17 | along with GNU Emacs; see the file COPYING. If not, write to | |
3b7ad313 EN |
18 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
dcfdbac7 JB |
20 | |
21 | /* NOTES: | |
22 | ||
eb8c3be9 | 23 | Only relocate the blocs necessary for SIZE in r_alloc_sbrk, |
dcfdbac7 | 24 | rather than all of them. This means allowing for a possible |
abe9ff32 | 25 | hole between the first bloc and the end of malloc storage. */ |
dcfdbac7 | 26 | |
2c46d29f | 27 | #ifdef emacs |
aef4d570 | 28 | |
18160b98 | 29 | #include <config.h> |
956ace37 | 30 | #include "lisp.h" /* Needed for VALBITS. */ |
2c46d29f | 31 | |
aef4d570 RM |
32 | #undef NULL |
33 | ||
f275fd9a RS |
34 | /* The important properties of this type are that 1) it's a pointer, and |
35 | 2) arithmetic on it should work as if the size of the object pointed | |
36 | to has a size of 1. */ | |
a8c0e5ea | 37 | #if 0 /* Arithmetic on void* is a GCC extension. */ |
f275fd9a RS |
38 | #ifdef __STDC__ |
39 | typedef void *POINTER; | |
40 | #else | |
1df181b6 RM |
41 | |
42 | #ifdef HAVE_CONFIG_H | |
43 | #include "config.h" | |
44 | #endif | |
45 | ||
f275fd9a | 46 | typedef char *POINTER; |
1df181b6 | 47 | |
f275fd9a | 48 | #endif |
a8c0e5ea RS |
49 | #endif /* 0 */ |
50 | ||
51 | /* Unconditionally use char * for this. */ | |
52 | typedef char *POINTER; | |
f275fd9a RS |
53 | |
54 | typedef unsigned long SIZE; | |
55 | ||
2c46d29f RS |
56 | /* Declared in dispnew.c, this version doesn't screw up if regions |
57 | overlap. */ | |
58 | extern void safe_bcopy (); | |
2c46d29f | 59 | |
b0119c68 RS |
60 | #ifdef DOUG_LEA_MALLOC |
61 | #define M_TOP_PAD -2 | |
62 | extern int mallopt (); | |
63 | #else | |
49081834 | 64 | extern int __malloc_extra_blocks; |
b0119c68 | 65 | #endif |
49081834 | 66 | |
d5179acc | 67 | #else /* not emacs */ |
aef4d570 | 68 | |
2c46d29f | 69 | #include <stddef.h> |
aef4d570 | 70 | |
2c46d29f RS |
71 | typedef size_t SIZE; |
72 | typedef void *POINTER; | |
aef4d570 | 73 | |
aef4d570 RM |
74 | #include <unistd.h> |
75 | #include <malloc.h> | |
76 | #include <string.h> | |
77 | ||
2c46d29f | 78 | #define safe_bcopy(x, y, z) memmove (y, x, z) |
d5179acc RS |
79 | #define bzero(x, len) memset (x, 0, len) |
80 | ||
81 | #endif /* not emacs */ | |
2c46d29f | 82 | |
d5179acc | 83 | #include "getpagesize.h" |
dcfdbac7 JB |
84 | |
85 | #define NIL ((POINTER) 0) | |
86 | ||
2c46d29f RS |
87 | /* A flag to indicate whether we have initialized ralloc yet. For |
88 | Emacs's sake, please do not make this local to malloc_init; on some | |
89 | machines, the dumping procedure makes all static variables | |
90 | read-only. On these machines, the word static is #defined to be | |
91 | the empty string, meaning that r_alloc_initialized becomes an | |
92 | automatic variable, and loses its value each time Emacs is started up. */ | |
93 | static int r_alloc_initialized = 0; | |
94 | ||
95 | static void r_alloc_init (); | |
dcfdbac7 | 96 | \f |
956ace37 JB |
97 | /* Declarations for working with the malloc, ralloc, and system breaks. */ |
98 | ||
abe9ff32 | 99 | /* Function to set the real break value. */ |
bbc60227 | 100 | static POINTER (*real_morecore) (); |
dcfdbac7 | 101 | |
abe9ff32 | 102 | /* The break value, as seen by malloc. */ |
dcfdbac7 JB |
103 | static POINTER virtual_break_value; |
104 | ||
abe9ff32 RS |
105 | /* The address of the end of the last data in use by ralloc, |
106 | including relocatable blocs as well as malloc data. */ | |
dcfdbac7 JB |
107 | static POINTER break_value; |
108 | ||
7516b7d5 RS |
109 | /* This is the size of a page. We round memory requests to this boundary. */ |
110 | static int page_size; | |
111 | ||
ad3bb3d2 JB |
112 | /* Whenever we get memory from the system, get this many extra bytes. This |
113 | must be a multiple of page_size. */ | |
7516b7d5 RS |
114 | static int extra_bytes; |
115 | ||
dcfdbac7 | 116 | /* Macros for rounding. Note that rounding to any value is possible |
abe9ff32 | 117 | by changing the definition of PAGE. */ |
dcfdbac7 | 118 | #define PAGE (getpagesize ()) |
f7a009a5 RM |
119 | #define ALIGNED(addr) (((unsigned long int) (addr) & (page_size - 1)) == 0) |
120 | #define ROUNDUP(size) (((unsigned long int) (size) + page_size - 1) \ | |
121 | & ~(page_size - 1)) | |
7516b7d5 | 122 | #define ROUND_TO_PAGE(addr) (addr & (~(page_size - 1))) |
e429caa2 KH |
123 | |
124 | #define MEM_ALIGN sizeof(double) | |
125 | #define MEM_ROUNDUP(addr) (((unsigned long int)(addr) + MEM_ALIGN - 1) \ | |
126 | & ~(MEM_ALIGN - 1)) | |
127 | \f | |
abe9ff32 RS |
128 | /* Data structures of heaps and blocs. */ |
129 | ||
130 | /* The relocatable objects, or blocs, and the malloc data | |
131 | both reside within one or more heaps. | |
132 | Each heap contains malloc data, running from `start' to `bloc_start', | |
133 | and relocatable objects, running from `bloc_start' to `free'. | |
134 | ||
135 | Relocatable objects may relocate within the same heap | |
136 | or may move into another heap; the heaps themselves may grow | |
137 | but they never move. | |
138 | ||
139 | We try to make just one heap and make it larger as necessary. | |
8e6208c5 | 140 | But sometimes we can't do that, because we can't get contiguous |
abe9ff32 RS |
141 | space to add onto the heap. When that happens, we start a new heap. */ |
142 | ||
e429caa2 KH |
143 | typedef struct heap |
144 | { | |
145 | struct heap *next; | |
146 | struct heap *prev; | |
abe9ff32 | 147 | /* Start of memory range of this heap. */ |
e429caa2 | 148 | POINTER start; |
abe9ff32 | 149 | /* End of memory range of this heap. */ |
e429caa2 | 150 | POINTER end; |
abe9ff32 RS |
151 | /* Start of relocatable data in this heap. */ |
152 | POINTER bloc_start; | |
153 | /* Start of unused space in this heap. */ | |
154 | POINTER free; | |
47f13333 RS |
155 | /* First bloc in this heap. */ |
156 | struct bp *first_bloc; | |
157 | /* Last bloc in this heap. */ | |
158 | struct bp *last_bloc; | |
e429caa2 KH |
159 | } *heap_ptr; |
160 | ||
161 | #define NIL_HEAP ((heap_ptr) 0) | |
162 | #define HEAP_PTR_SIZE (sizeof (struct heap)) | |
163 | ||
abe9ff32 RS |
164 | /* This is the first heap object. |
165 | If we need additional heap objects, each one resides at the beginning of | |
166 | the space it covers. */ | |
167 | static struct heap heap_base; | |
168 | ||
169 | /* Head and tail of the list of heaps. */ | |
e429caa2 KH |
170 | static heap_ptr first_heap, last_heap; |
171 | ||
172 | /* These structures are allocated in the malloc arena. | |
173 | The linked list is kept in order of increasing '.data' members. | |
174 | The data blocks abut each other; if b->next is non-nil, then | |
49f82b3d RS |
175 | b->data + b->size == b->next->data. |
176 | ||
177 | An element with variable==NIL denotes a freed block, which has not yet | |
178 | been collected. They may only appear while r_alloc_freeze > 0, and will be | |
179 | freed when the arena is thawed. Currently, these blocs are not reusable, | |
8e6208c5 | 180 | while the arena is frozen. Very inefficient. */ |
49f82b3d | 181 | |
e429caa2 KH |
182 | typedef struct bp |
183 | { | |
184 | struct bp *next; | |
185 | struct bp *prev; | |
186 | POINTER *variable; | |
187 | POINTER data; | |
188 | SIZE size; | |
8e6208c5 | 189 | POINTER new_data; /* temporarily used for relocation */ |
49f82b3d | 190 | struct heap *heap; /* Heap this bloc is in. */ |
e429caa2 KH |
191 | } *bloc_ptr; |
192 | ||
193 | #define NIL_BLOC ((bloc_ptr) 0) | |
194 | #define BLOC_PTR_SIZE (sizeof (struct bp)) | |
195 | ||
abe9ff32 | 196 | /* Head and tail of the list of relocatable blocs. */ |
e429caa2 KH |
197 | static bloc_ptr first_bloc, last_bloc; |
198 | ||
49f82b3d RS |
199 | static int use_relocatable_buffers; |
200 | ||
201 | /* If >0, no relocation whatsoever takes place. */ | |
202 | static int r_alloc_freeze_level; | |
203 | ||
dcfdbac7 | 204 | \f |
956ace37 JB |
205 | /* Functions to get and return memory from the system. */ |
206 | ||
abe9ff32 RS |
207 | /* Find the heap that ADDRESS falls within. */ |
208 | ||
209 | static heap_ptr | |
210 | find_heap (address) | |
211 | POINTER address; | |
212 | { | |
213 | heap_ptr heap; | |
214 | ||
215 | for (heap = last_heap; heap; heap = heap->prev) | |
216 | { | |
217 | if (heap->start <= address && address <= heap->end) | |
218 | return heap; | |
219 | } | |
220 | ||
221 | return NIL_HEAP; | |
222 | } | |
223 | ||
224 | /* Find SIZE bytes of space in a heap. | |
225 | Try to get them at ADDRESS (which must fall within some heap's range) | |
226 | if we can get that many within one heap. | |
227 | ||
e429caa2 | 228 | If enough space is not presently available in our reserve, this means |
8e6208c5 KH |
229 | getting more page-aligned space from the system. If the returned space |
230 | is not contiguous to the last heap, allocate a new heap, and append it | |
abe9ff32 RS |
231 | |
232 | obtain does not try to keep track of whether space is in use | |
233 | or not in use. It just returns the address of SIZE bytes that | |
234 | fall within a single heap. If you call obtain twice in a row | |
235 | with the same arguments, you typically get the same value. | |
236 | to the heap list. It's the caller's responsibility to keep | |
237 | track of what space is in use. | |
dcfdbac7 | 238 | |
e429caa2 KH |
239 | Return the address of the space if all went well, or zero if we couldn't |
240 | allocate the memory. */ | |
abe9ff32 | 241 | |
e429caa2 KH |
242 | static POINTER |
243 | obtain (address, size) | |
244 | POINTER address; | |
245 | SIZE size; | |
dcfdbac7 | 246 | { |
e429caa2 KH |
247 | heap_ptr heap; |
248 | SIZE already_available; | |
dcfdbac7 | 249 | |
abe9ff32 | 250 | /* Find the heap that ADDRESS falls within. */ |
e429caa2 | 251 | for (heap = last_heap; heap; heap = heap->prev) |
dcfdbac7 | 252 | { |
e429caa2 KH |
253 | if (heap->start <= address && address <= heap->end) |
254 | break; | |
255 | } | |
dcfdbac7 | 256 | |
e429caa2 | 257 | if (! heap) |
abe9ff32 | 258 | abort (); |
dcfdbac7 | 259 | |
abe9ff32 RS |
260 | /* If we can't fit SIZE bytes in that heap, |
261 | try successive later heaps. */ | |
e429caa2 KH |
262 | while (heap && address + size > heap->end) |
263 | { | |
264 | heap = heap->next; | |
265 | if (heap == NIL_HEAP) | |
266 | break; | |
267 | address = heap->bloc_start; | |
dcfdbac7 JB |
268 | } |
269 | ||
abe9ff32 RS |
270 | /* If we can't fit them within any existing heap, |
271 | get more space. */ | |
e429caa2 KH |
272 | if (heap == NIL_HEAP) |
273 | { | |
274 | POINTER new = (*real_morecore)(0); | |
275 | SIZE get; | |
98b7fe02 | 276 | |
e429caa2 | 277 | already_available = (char *)last_heap->end - (char *)address; |
dcfdbac7 | 278 | |
e429caa2 KH |
279 | if (new != last_heap->end) |
280 | { | |
abe9ff32 RS |
281 | /* Someone else called sbrk. Make a new heap. */ |
282 | ||
283 | heap_ptr new_heap = (heap_ptr) MEM_ROUNDUP (new); | |
284 | POINTER bloc_start = (POINTER) MEM_ROUNDUP ((POINTER)(new_heap + 1)); | |
e429caa2 KH |
285 | |
286 | if ((*real_morecore) (bloc_start - new) != new) | |
287 | return 0; | |
288 | ||
289 | new_heap->start = new; | |
290 | new_heap->end = bloc_start; | |
291 | new_heap->bloc_start = bloc_start; | |
abe9ff32 | 292 | new_heap->free = bloc_start; |
e429caa2 KH |
293 | new_heap->next = NIL_HEAP; |
294 | new_heap->prev = last_heap; | |
47f13333 RS |
295 | new_heap->first_bloc = NIL_BLOC; |
296 | new_heap->last_bloc = NIL_BLOC; | |
e429caa2 KH |
297 | last_heap->next = new_heap; |
298 | last_heap = new_heap; | |
299 | ||
300 | address = bloc_start; | |
301 | already_available = 0; | |
302 | } | |
dcfdbac7 | 303 | |
abe9ff32 RS |
304 | /* Add space to the last heap (which we may have just created). |
305 | Get some extra, so we can come here less often. */ | |
306 | ||
e429caa2 | 307 | get = size + extra_bytes - already_available; |
abe9ff32 | 308 | get = (char *) ROUNDUP ((char *)last_heap->end + get) |
e429caa2 | 309 | - (char *) last_heap->end; |
dcfdbac7 | 310 | |
e429caa2 KH |
311 | if ((*real_morecore) (get) != last_heap->end) |
312 | return 0; | |
313 | ||
314 | last_heap->end += get; | |
315 | } | |
316 | ||
317 | return address; | |
318 | } | |
dcfdbac7 | 319 | |
abe9ff32 RS |
320 | /* Return unused heap space to the system |
321 | if there is a lot of unused space now. | |
322 | This can make the last heap smaller; | |
323 | it can also eliminate the last heap entirely. */ | |
324 | ||
dcfdbac7 | 325 | static void |
e429caa2 | 326 | relinquish () |
dcfdbac7 | 327 | { |
e429caa2 KH |
328 | register heap_ptr h; |
329 | int excess = 0; | |
330 | ||
abe9ff32 RS |
331 | /* Add the amount of space beyond break_value |
332 | in all heaps which have extend beyond break_value at all. */ | |
333 | ||
e429caa2 KH |
334 | for (h = last_heap; h && break_value < h->end; h = h->prev) |
335 | { | |
336 | excess += (char *) h->end - (char *) ((break_value < h->bloc_start) | |
337 | ? h->bloc_start : break_value); | |
338 | } | |
339 | ||
340 | if (excess > extra_bytes * 2 && (*real_morecore) (0) == last_heap->end) | |
dcfdbac7 | 341 | { |
7516b7d5 RS |
342 | /* Keep extra_bytes worth of empty space. |
343 | And don't free anything unless we can free at least extra_bytes. */ | |
e429caa2 | 344 | excess -= extra_bytes; |
dcfdbac7 | 345 | |
e429caa2 KH |
346 | if ((char *)last_heap->end - (char *)last_heap->bloc_start <= excess) |
347 | { | |
47f13333 RS |
348 | /* This heap should have no blocs in it. */ |
349 | if (last_heap->first_bloc != NIL_BLOC | |
350 | || last_heap->last_bloc != NIL_BLOC) | |
351 | abort (); | |
352 | ||
abe9ff32 | 353 | /* Return the last heap, with its header, to the system. */ |
e429caa2 KH |
354 | excess = (char *)last_heap->end - (char *)last_heap->start; |
355 | last_heap = last_heap->prev; | |
356 | last_heap->next = NIL_HEAP; | |
357 | } | |
358 | else | |
359 | { | |
360 | excess = (char *) last_heap->end | |
abe9ff32 | 361 | - (char *) ROUNDUP ((char *)last_heap->end - excess); |
e429caa2 KH |
362 | last_heap->end -= excess; |
363 | } | |
dcfdbac7 | 364 | |
e429caa2 | 365 | if ((*real_morecore) (- excess) == 0) |
21532667 KH |
366 | { |
367 | /* If the system didn't want that much memory back, adjust | |
368 | the end of the last heap to reflect that. This can occur | |
369 | if break_value is still within the original data segment. */ | |
370 | last_heap->end += excess; | |
371 | /* Make sure that the result of the adjustment is accurate. | |
372 | It should be, for the else clause above; the other case, | |
373 | which returns the entire last heap to the system, seems | |
374 | unlikely to trigger this mode of failure. */ | |
375 | if (last_heap->end != (*real_morecore) (0)) | |
376 | abort (); | |
377 | } | |
e429caa2 | 378 | } |
dcfdbac7 | 379 | } |
719b242f RS |
380 | |
381 | /* Return the total size in use by relocating allocator, | |
382 | above where malloc gets space. */ | |
383 | ||
384 | long | |
385 | r_alloc_size_in_use () | |
386 | { | |
387 | return break_value - virtual_break_value; | |
388 | } | |
dcfdbac7 | 389 | \f |
956ace37 JB |
390 | /* The meat - allocating, freeing, and relocating blocs. */ |
391 | ||
956ace37 | 392 | /* Find the bloc referenced by the address in PTR. Returns a pointer |
abe9ff32 | 393 | to that block. */ |
dcfdbac7 JB |
394 | |
395 | static bloc_ptr | |
396 | find_bloc (ptr) | |
397 | POINTER *ptr; | |
398 | { | |
399 | register bloc_ptr p = first_bloc; | |
400 | ||
401 | while (p != NIL_BLOC) | |
402 | { | |
403 | if (p->variable == ptr && p->data == *ptr) | |
404 | return p; | |
405 | ||
406 | p = p->next; | |
407 | } | |
408 | ||
409 | return p; | |
410 | } | |
411 | ||
412 | /* Allocate a bloc of SIZE bytes and append it to the chain of blocs. | |
98b7fe02 JB |
413 | Returns a pointer to the new bloc, or zero if we couldn't allocate |
414 | memory for the new block. */ | |
dcfdbac7 JB |
415 | |
416 | static bloc_ptr | |
417 | get_bloc (size) | |
418 | SIZE size; | |
419 | { | |
98b7fe02 | 420 | register bloc_ptr new_bloc; |
abe9ff32 | 421 | register heap_ptr heap; |
98b7fe02 JB |
422 | |
423 | if (! (new_bloc = (bloc_ptr) malloc (BLOC_PTR_SIZE)) | |
e429caa2 | 424 | || ! (new_bloc->data = obtain (break_value, size))) |
98b7fe02 JB |
425 | { |
426 | if (new_bloc) | |
427 | free (new_bloc); | |
428 | ||
429 | return 0; | |
430 | } | |
dcfdbac7 | 431 | |
e429caa2 KH |
432 | break_value = new_bloc->data + size; |
433 | ||
dcfdbac7 JB |
434 | new_bloc->size = size; |
435 | new_bloc->next = NIL_BLOC; | |
8c7f1e35 | 436 | new_bloc->variable = (POINTER *) NIL; |
e429caa2 | 437 | new_bloc->new_data = 0; |
dcfdbac7 | 438 | |
abe9ff32 RS |
439 | /* Record in the heap that this space is in use. */ |
440 | heap = find_heap (new_bloc->data); | |
441 | heap->free = break_value; | |
442 | ||
47f13333 RS |
443 | /* Maintain the correspondence between heaps and blocs. */ |
444 | new_bloc->heap = heap; | |
445 | heap->last_bloc = new_bloc; | |
446 | if (heap->first_bloc == NIL_BLOC) | |
447 | heap->first_bloc = new_bloc; | |
448 | ||
abe9ff32 | 449 | /* Put this bloc on the doubly-linked list of blocs. */ |
dcfdbac7 JB |
450 | if (first_bloc) |
451 | { | |
452 | new_bloc->prev = last_bloc; | |
453 | last_bloc->next = new_bloc; | |
454 | last_bloc = new_bloc; | |
455 | } | |
456 | else | |
457 | { | |
458 | first_bloc = last_bloc = new_bloc; | |
459 | new_bloc->prev = NIL_BLOC; | |
460 | } | |
461 | ||
462 | return new_bloc; | |
463 | } | |
47f13333 | 464 | \f |
abe9ff32 RS |
465 | /* Calculate new locations of blocs in the list beginning with BLOC, |
466 | relocating it to start at ADDRESS, in heap HEAP. If enough space is | |
467 | not presently available in our reserve, call obtain for | |
e429caa2 KH |
468 | more space. |
469 | ||
abe9ff32 RS |
470 | Store the new location of each bloc in its new_data field. |
471 | Do not touch the contents of blocs or break_value. */ | |
dcfdbac7 | 472 | |
e429caa2 KH |
473 | static int |
474 | relocate_blocs (bloc, heap, address) | |
475 | bloc_ptr bloc; | |
476 | heap_ptr heap; | |
477 | POINTER address; | |
478 | { | |
479 | register bloc_ptr b = bloc; | |
ad3bb3d2 | 480 | |
49f82b3d RS |
481 | /* No need to ever call this if arena is frozen, bug somewhere! */ |
482 | if (r_alloc_freeze_level) | |
483 | abort(); | |
484 | ||
e429caa2 KH |
485 | while (b) |
486 | { | |
abe9ff32 RS |
487 | /* If bloc B won't fit within HEAP, |
488 | move to the next heap and try again. */ | |
e429caa2 KH |
489 | while (heap && address + b->size > heap->end) |
490 | { | |
491 | heap = heap->next; | |
492 | if (heap == NIL_HEAP) | |
493 | break; | |
494 | address = heap->bloc_start; | |
495 | } | |
dcfdbac7 | 496 | |
abe9ff32 RS |
497 | /* If BLOC won't fit in any heap, |
498 | get enough new space to hold BLOC and all following blocs. */ | |
e429caa2 KH |
499 | if (heap == NIL_HEAP) |
500 | { | |
501 | register bloc_ptr tb = b; | |
502 | register SIZE s = 0; | |
503 | ||
abe9ff32 | 504 | /* Add up the size of all the following blocs. */ |
e429caa2 KH |
505 | while (tb != NIL_BLOC) |
506 | { | |
49f82b3d RS |
507 | if (tb->variable) |
508 | s += tb->size; | |
509 | ||
e429caa2 KH |
510 | tb = tb->next; |
511 | } | |
512 | ||
abe9ff32 RS |
513 | /* Get that space. */ |
514 | address = obtain (address, s); | |
515 | if (address == 0) | |
e429caa2 KH |
516 | return 0; |
517 | ||
518 | heap = last_heap; | |
519 | } | |
520 | ||
abe9ff32 RS |
521 | /* Record the new address of this bloc |
522 | and update where the next bloc can start. */ | |
e429caa2 | 523 | b->new_data = address; |
49f82b3d RS |
524 | if (b->variable) |
525 | address += b->size; | |
e429caa2 KH |
526 | b = b->next; |
527 | } | |
528 | ||
529 | return 1; | |
530 | } | |
531 | ||
47f13333 RS |
532 | /* Reorder the bloc BLOC to go before bloc BEFORE in the doubly linked list. |
533 | This is necessary if we put the memory of space of BLOC | |
534 | before that of BEFORE. */ | |
535 | ||
536 | static void | |
537 | reorder_bloc (bloc, before) | |
538 | bloc_ptr bloc, before; | |
539 | { | |
540 | bloc_ptr prev, next; | |
541 | ||
542 | /* Splice BLOC out from where it is. */ | |
543 | prev = bloc->prev; | |
544 | next = bloc->next; | |
545 | ||
546 | if (prev) | |
547 | prev->next = next; | |
548 | if (next) | |
549 | next->prev = prev; | |
550 | ||
551 | /* Splice it in before BEFORE. */ | |
552 | prev = before->prev; | |
abe9ff32 | 553 | |
47f13333 RS |
554 | if (prev) |
555 | prev->next = bloc; | |
556 | bloc->prev = prev; | |
557 | ||
558 | before->prev = bloc; | |
559 | bloc->next = before; | |
560 | } | |
561 | \f | |
562 | /* Update the records of which heaps contain which blocs, starting | |
563 | with heap HEAP and bloc BLOC. */ | |
564 | ||
565 | static void | |
566 | update_heap_bloc_correspondence (bloc, heap) | |
abe9ff32 RS |
567 | bloc_ptr bloc; |
568 | heap_ptr heap; | |
569 | { | |
570 | register bloc_ptr b; | |
571 | ||
47f13333 RS |
572 | /* Initialize HEAP's status to reflect blocs before BLOC. */ |
573 | if (bloc != NIL_BLOC && bloc->prev != NIL_BLOC && bloc->prev->heap == heap) | |
574 | { | |
575 | /* The previous bloc is in HEAP. */ | |
576 | heap->last_bloc = bloc->prev; | |
577 | heap->free = bloc->prev->data + bloc->prev->size; | |
578 | } | |
579 | else | |
580 | { | |
581 | /* HEAP contains no blocs before BLOC. */ | |
582 | heap->first_bloc = NIL_BLOC; | |
583 | heap->last_bloc = NIL_BLOC; | |
584 | heap->free = heap->bloc_start; | |
585 | } | |
586 | ||
abe9ff32 RS |
587 | /* Advance through blocs one by one. */ |
588 | for (b = bloc; b != NIL_BLOC; b = b->next) | |
589 | { | |
47f13333 RS |
590 | /* Advance through heaps, marking them empty, |
591 | till we get to the one that B is in. */ | |
abe9ff32 RS |
592 | while (heap) |
593 | { | |
594 | if (heap->bloc_start <= b->data && b->data <= heap->end) | |
595 | break; | |
596 | heap = heap->next; | |
47f13333 RS |
597 | /* We know HEAP is not null now, |
598 | because there has to be space for bloc B. */ | |
599 | heap->first_bloc = NIL_BLOC; | |
600 | heap->last_bloc = NIL_BLOC; | |
abe9ff32 RS |
601 | heap->free = heap->bloc_start; |
602 | } | |
47f13333 RS |
603 | |
604 | /* Update HEAP's status for bloc B. */ | |
abe9ff32 | 605 | heap->free = b->data + b->size; |
47f13333 RS |
606 | heap->last_bloc = b; |
607 | if (heap->first_bloc == NIL_BLOC) | |
608 | heap->first_bloc = b; | |
609 | ||
610 | /* Record that B is in HEAP. */ | |
611 | b->heap = heap; | |
abe9ff32 RS |
612 | } |
613 | ||
614 | /* If there are any remaining heaps and no blocs left, | |
47f13333 | 615 | mark those heaps as empty. */ |
abe9ff32 RS |
616 | heap = heap->next; |
617 | while (heap) | |
618 | { | |
47f13333 RS |
619 | heap->first_bloc = NIL_BLOC; |
620 | heap->last_bloc = NIL_BLOC; | |
abe9ff32 RS |
621 | heap->free = heap->bloc_start; |
622 | heap = heap->next; | |
623 | } | |
624 | } | |
47f13333 | 625 | \f |
abe9ff32 RS |
626 | /* Resize BLOC to SIZE bytes. This relocates the blocs |
627 | that come after BLOC in memory. */ | |
628 | ||
e429caa2 KH |
629 | static int |
630 | resize_bloc (bloc, size) | |
631 | bloc_ptr bloc; | |
632 | SIZE size; | |
dcfdbac7 | 633 | { |
e429caa2 KH |
634 | register bloc_ptr b; |
635 | heap_ptr heap; | |
636 | POINTER address; | |
637 | SIZE old_size; | |
638 | ||
49f82b3d RS |
639 | /* No need to ever call this if arena is frozen, bug somewhere! */ |
640 | if (r_alloc_freeze_level) | |
641 | abort(); | |
642 | ||
e429caa2 KH |
643 | if (bloc == NIL_BLOC || size == bloc->size) |
644 | return 1; | |
645 | ||
646 | for (heap = first_heap; heap != NIL_HEAP; heap = heap->next) | |
647 | { | |
648 | if (heap->bloc_start <= bloc->data && bloc->data <= heap->end) | |
649 | break; | |
650 | } | |
651 | ||
652 | if (heap == NIL_HEAP) | |
abe9ff32 | 653 | abort (); |
e429caa2 KH |
654 | |
655 | old_size = bloc->size; | |
656 | bloc->size = size; | |
657 | ||
abe9ff32 RS |
658 | /* Note that bloc could be moved into the previous heap. */ |
659 | address = (bloc->prev ? bloc->prev->data + bloc->prev->size | |
660 | : first_heap->bloc_start); | |
e429caa2 KH |
661 | while (heap) |
662 | { | |
663 | if (heap->bloc_start <= address && address <= heap->end) | |
664 | break; | |
665 | heap = heap->prev; | |
666 | } | |
667 | ||
668 | if (! relocate_blocs (bloc, heap, address)) | |
669 | { | |
670 | bloc->size = old_size; | |
671 | return 0; | |
672 | } | |
673 | ||
674 | if (size > old_size) | |
675 | { | |
676 | for (b = last_bloc; b != bloc; b = b->prev) | |
677 | { | |
49f82b3d RS |
678 | if (!b->variable) |
679 | { | |
680 | b->size = 0; | |
681 | b->data = b->new_data; | |
682 | } | |
683 | else | |
684 | { | |
685 | safe_bcopy (b->data, b->new_data, b->size); | |
686 | *b->variable = b->data = b->new_data; | |
687 | } | |
688 | } | |
689 | if (!bloc->variable) | |
690 | { | |
691 | bloc->size = 0; | |
692 | bloc->data = bloc->new_data; | |
693 | } | |
694 | else | |
695 | { | |
696 | safe_bcopy (bloc->data, bloc->new_data, old_size); | |
697 | bzero (bloc->new_data + old_size, size - old_size); | |
698 | *bloc->variable = bloc->data = bloc->new_data; | |
e429caa2 | 699 | } |
e429caa2 KH |
700 | } |
701 | else | |
dcfdbac7 | 702 | { |
ad3bb3d2 JB |
703 | for (b = bloc; b != NIL_BLOC; b = b->next) |
704 | { | |
49f82b3d RS |
705 | if (!b->variable) |
706 | { | |
707 | b->size = 0; | |
708 | b->data = b->new_data; | |
709 | } | |
710 | else | |
711 | { | |
712 | safe_bcopy (b->data, b->new_data, b->size); | |
713 | *b->variable = b->data = b->new_data; | |
714 | } | |
ad3bb3d2 | 715 | } |
ad3bb3d2 | 716 | } |
dcfdbac7 | 717 | |
47f13333 | 718 | update_heap_bloc_correspondence (bloc, heap); |
abe9ff32 RS |
719 | |
720 | break_value = (last_bloc ? last_bloc->data + last_bloc->size | |
721 | : first_heap->bloc_start); | |
e429caa2 KH |
722 | return 1; |
723 | } | |
47f13333 | 724 | \f |
abe9ff32 RS |
725 | /* Free BLOC from the chain of blocs, relocating any blocs above it. |
726 | This may return space to the system. */ | |
dcfdbac7 JB |
727 | |
728 | static void | |
729 | free_bloc (bloc) | |
730 | bloc_ptr bloc; | |
731 | { | |
47f13333 RS |
732 | heap_ptr heap = bloc->heap; |
733 | ||
49f82b3d RS |
734 | if (r_alloc_freeze_level) |
735 | { | |
736 | bloc->variable = (POINTER *) NIL; | |
737 | return; | |
738 | } | |
739 | ||
e429caa2 KH |
740 | resize_bloc (bloc, 0); |
741 | ||
dcfdbac7 JB |
742 | if (bloc == first_bloc && bloc == last_bloc) |
743 | { | |
744 | first_bloc = last_bloc = NIL_BLOC; | |
745 | } | |
746 | else if (bloc == last_bloc) | |
747 | { | |
748 | last_bloc = bloc->prev; | |
749 | last_bloc->next = NIL_BLOC; | |
750 | } | |
751 | else if (bloc == first_bloc) | |
752 | { | |
753 | first_bloc = bloc->next; | |
754 | first_bloc->prev = NIL_BLOC; | |
dcfdbac7 JB |
755 | } |
756 | else | |
757 | { | |
758 | bloc->next->prev = bloc->prev; | |
759 | bloc->prev->next = bloc->next; | |
dcfdbac7 JB |
760 | } |
761 | ||
47f13333 RS |
762 | /* Update the records of which blocs are in HEAP. */ |
763 | if (heap->first_bloc == bloc) | |
764 | { | |
d5179acc | 765 | if (bloc->next != 0 && bloc->next->heap == heap) |
47f13333 RS |
766 | heap->first_bloc = bloc->next; |
767 | else | |
768 | heap->first_bloc = heap->last_bloc = NIL_BLOC; | |
769 | } | |
770 | if (heap->last_bloc == bloc) | |
771 | { | |
d5179acc | 772 | if (bloc->prev != 0 && bloc->prev->heap == heap) |
47f13333 RS |
773 | heap->last_bloc = bloc->prev; |
774 | else | |
775 | heap->first_bloc = heap->last_bloc = NIL_BLOC; | |
776 | } | |
777 | ||
e429caa2 | 778 | relinquish (); |
dcfdbac7 JB |
779 | free (bloc); |
780 | } | |
781 | \f | |
956ace37 JB |
782 | /* Interface routines. */ |
783 | ||
98b7fe02 | 784 | /* Obtain SIZE bytes of storage from the free pool, or the system, as |
2c46d29f | 785 | necessary. If relocatable blocs are in use, this means relocating |
98b7fe02 JB |
786 | them. This function gets plugged into the GNU malloc's __morecore |
787 | hook. | |
788 | ||
7516b7d5 RS |
789 | We provide hysteresis, never relocating by less than extra_bytes. |
790 | ||
98b7fe02 JB |
791 | If we're out of memory, we should return zero, to imitate the other |
792 | __morecore hook values - in particular, __default_morecore in the | |
793 | GNU malloc package. */ | |
dcfdbac7 JB |
794 | |
795 | POINTER | |
796 | r_alloc_sbrk (size) | |
797 | long size; | |
798 | { | |
e429caa2 KH |
799 | register bloc_ptr b; |
800 | POINTER address; | |
dcfdbac7 | 801 | |
44d3dec0 RS |
802 | if (! r_alloc_initialized) |
803 | r_alloc_init (); | |
804 | ||
dcfdbac7 | 805 | if (! use_relocatable_buffers) |
bbc60227 | 806 | return (*real_morecore) (size); |
dcfdbac7 | 807 | |
e429caa2 KH |
808 | if (size == 0) |
809 | return virtual_break_value; | |
7516b7d5 | 810 | |
e429caa2 | 811 | if (size > 0) |
dcfdbac7 | 812 | { |
abe9ff32 RS |
813 | /* Allocate a page-aligned space. GNU malloc would reclaim an |
814 | extra space if we passed an unaligned one. But we could | |
8e6208c5 | 815 | not always find a space which is contiguous to the previous. */ |
e429caa2 KH |
816 | POINTER new_bloc_start; |
817 | heap_ptr h = first_heap; | |
abe9ff32 | 818 | SIZE get = ROUNDUP (size); |
7516b7d5 | 819 | |
abe9ff32 | 820 | address = (POINTER) ROUNDUP (virtual_break_value); |
e429caa2 | 821 | |
abe9ff32 RS |
822 | /* Search the list upward for a heap which is large enough. */ |
823 | while ((char *) h->end < (char *) MEM_ROUNDUP ((char *)address + get)) | |
e429caa2 KH |
824 | { |
825 | h = h->next; | |
826 | if (h == NIL_HEAP) | |
827 | break; | |
abe9ff32 | 828 | address = (POINTER) ROUNDUP (h->start); |
e429caa2 KH |
829 | } |
830 | ||
abe9ff32 | 831 | /* If not found, obtain more space. */ |
e429caa2 KH |
832 | if (h == NIL_HEAP) |
833 | { | |
834 | get += extra_bytes + page_size; | |
835 | ||
49f82b3d | 836 | if (! obtain (address, get)) |
e429caa2 | 837 | return 0; |
98b7fe02 | 838 | |
e429caa2 | 839 | if (first_heap == last_heap) |
abe9ff32 | 840 | address = (POINTER) ROUNDUP (virtual_break_value); |
e429caa2 | 841 | else |
abe9ff32 | 842 | address = (POINTER) ROUNDUP (last_heap->start); |
e429caa2 KH |
843 | h = last_heap; |
844 | } | |
845 | ||
abe9ff32 | 846 | new_bloc_start = (POINTER) MEM_ROUNDUP ((char *)address + get); |
e429caa2 KH |
847 | |
848 | if (first_heap->bloc_start < new_bloc_start) | |
849 | { | |
49f82b3d RS |
850 | /* This is no clean solution - no idea how to do it better. */ |
851 | if (r_alloc_freeze_level) | |
852 | return NIL; | |
853 | ||
854 | /* There is a bug here: if the above obtain call succeeded, but the | |
855 | relocate_blocs call below does not succeed, we need to free | |
856 | the memory that we got with obtain. */ | |
857 | ||
abe9ff32 | 858 | /* Move all blocs upward. */ |
49f82b3d | 859 | if (! relocate_blocs (first_bloc, h, new_bloc_start)) |
e429caa2 KH |
860 | return 0; |
861 | ||
862 | /* Note that (POINTER)(h+1) <= new_bloc_start since | |
863 | get >= page_size, so the following does not destroy the heap | |
abe9ff32 | 864 | header. */ |
e429caa2 KH |
865 | for (b = last_bloc; b != NIL_BLOC; b = b->prev) |
866 | { | |
867 | safe_bcopy (b->data, b->new_data, b->size); | |
868 | *b->variable = b->data = b->new_data; | |
869 | } | |
870 | ||
871 | h->bloc_start = new_bloc_start; | |
abe9ff32 | 872 | |
47f13333 | 873 | update_heap_bloc_correspondence (first_bloc, h); |
e429caa2 | 874 | } |
e429caa2 KH |
875 | if (h != first_heap) |
876 | { | |
877 | /* Give up managing heaps below the one the new | |
abe9ff32 | 878 | virtual_break_value points to. */ |
e429caa2 KH |
879 | first_heap->prev = NIL_HEAP; |
880 | first_heap->next = h->next; | |
881 | first_heap->start = h->start; | |
882 | first_heap->end = h->end; | |
abe9ff32 | 883 | first_heap->free = h->free; |
47f13333 RS |
884 | first_heap->first_bloc = h->first_bloc; |
885 | first_heap->last_bloc = h->last_bloc; | |
e429caa2 KH |
886 | first_heap->bloc_start = h->bloc_start; |
887 | ||
888 | if (first_heap->next) | |
889 | first_heap->next->prev = first_heap; | |
890 | else | |
891 | last_heap = first_heap; | |
892 | } | |
893 | ||
894 | bzero (address, size); | |
dcfdbac7 | 895 | } |
e429caa2 | 896 | else /* size < 0 */ |
dcfdbac7 | 897 | { |
e429caa2 KH |
898 | SIZE excess = (char *)first_heap->bloc_start |
899 | - ((char *)virtual_break_value + size); | |
900 | ||
901 | address = virtual_break_value; | |
902 | ||
903 | if (r_alloc_freeze_level == 0 && excess > 2 * extra_bytes) | |
904 | { | |
905 | excess -= extra_bytes; | |
906 | first_heap->bloc_start | |
47f13333 | 907 | = (POINTER) MEM_ROUNDUP ((char *)first_heap->bloc_start - excess); |
e429caa2 | 908 | |
abe9ff32 | 909 | relocate_blocs (first_bloc, first_heap, first_heap->bloc_start); |
7516b7d5 | 910 | |
e429caa2 KH |
911 | for (b = first_bloc; b != NIL_BLOC; b = b->next) |
912 | { | |
913 | safe_bcopy (b->data, b->new_data, b->size); | |
914 | *b->variable = b->data = b->new_data; | |
915 | } | |
916 | } | |
917 | ||
918 | if ((char *)virtual_break_value + size < (char *)first_heap->start) | |
919 | { | |
920 | /* We found an additional space below the first heap */ | |
921 | first_heap->start = (POINTER) ((char *)virtual_break_value + size); | |
922 | } | |
dcfdbac7 JB |
923 | } |
924 | ||
e429caa2 | 925 | virtual_break_value = (POINTER) ((char *)address + size); |
47f13333 RS |
926 | break_value = (last_bloc |
927 | ? last_bloc->data + last_bloc->size | |
928 | : first_heap->bloc_start); | |
e429caa2 | 929 | if (size < 0) |
abe9ff32 | 930 | relinquish (); |
7516b7d5 | 931 | |
e429caa2 | 932 | return address; |
dcfdbac7 JB |
933 | } |
934 | ||
935 | /* Allocate a relocatable bloc of storage of size SIZE. A pointer to | |
936 | the data is returned in *PTR. PTR is thus the address of some variable | |
98b7fe02 JB |
937 | which will use the data area. |
938 | ||
49f82b3d RS |
939 | The allocation of 0 bytes is valid. |
940 | In case r_alloc_freeze is set, a best fit of unused blocs could be done | |
941 | before allocating a new area. Not yet done. | |
942 | ||
98b7fe02 JB |
943 | If we can't allocate the necessary memory, set *PTR to zero, and |
944 | return zero. */ | |
dcfdbac7 JB |
945 | |
946 | POINTER | |
947 | r_alloc (ptr, size) | |
948 | POINTER *ptr; | |
949 | SIZE size; | |
950 | { | |
951 | register bloc_ptr new_bloc; | |
952 | ||
2c46d29f RS |
953 | if (! r_alloc_initialized) |
954 | r_alloc_init (); | |
955 | ||
abe9ff32 | 956 | new_bloc = get_bloc (MEM_ROUNDUP (size)); |
98b7fe02 JB |
957 | if (new_bloc) |
958 | { | |
959 | new_bloc->variable = ptr; | |
960 | *ptr = new_bloc->data; | |
961 | } | |
962 | else | |
963 | *ptr = 0; | |
dcfdbac7 JB |
964 | |
965 | return *ptr; | |
966 | } | |
967 | ||
2c46d29f RS |
968 | /* Free a bloc of relocatable storage whose data is pointed to by PTR. |
969 | Store 0 in *PTR to show there's no block allocated. */ | |
dcfdbac7 JB |
970 | |
971 | void | |
972 | r_alloc_free (ptr) | |
973 | register POINTER *ptr; | |
974 | { | |
975 | register bloc_ptr dead_bloc; | |
976 | ||
44d3dec0 RS |
977 | if (! r_alloc_initialized) |
978 | r_alloc_init (); | |
979 | ||
dcfdbac7 JB |
980 | dead_bloc = find_bloc (ptr); |
981 | if (dead_bloc == NIL_BLOC) | |
982 | abort (); | |
983 | ||
984 | free_bloc (dead_bloc); | |
2c46d29f | 985 | *ptr = 0; |
719b242f | 986 | |
d5179acc | 987 | #ifdef emacs |
719b242f | 988 | refill_memory_reserve (); |
d5179acc | 989 | #endif |
dcfdbac7 JB |
990 | } |
991 | ||
16a5c729 | 992 | /* Given a pointer at address PTR to relocatable data, resize it to SIZE. |
98b7fe02 JB |
993 | Do this by shifting all blocks above this one up in memory, unless |
994 | SIZE is less than or equal to the current bloc size, in which case | |
995 | do nothing. | |
dcfdbac7 | 996 | |
49f82b3d | 997 | In case r_alloc_freeze is set, a new bloc is allocated, and the |
8e6208c5 | 998 | memory copied to it. Not very efficient. We could traverse the |
49f82b3d RS |
999 | bloc_list for a best fit of free blocs first. |
1000 | ||
98b7fe02 JB |
1001 | Change *PTR to reflect the new bloc, and return this value. |
1002 | ||
1003 | If more memory cannot be allocated, then leave *PTR unchanged, and | |
1004 | return zero. */ | |
dcfdbac7 JB |
1005 | |
1006 | POINTER | |
1007 | r_re_alloc (ptr, size) | |
1008 | POINTER *ptr; | |
1009 | SIZE size; | |
1010 | { | |
16a5c729 | 1011 | register bloc_ptr bloc; |
dcfdbac7 | 1012 | |
44d3dec0 RS |
1013 | if (! r_alloc_initialized) |
1014 | r_alloc_init (); | |
1015 | ||
49f82b3d RS |
1016 | if (!*ptr) |
1017 | return r_alloc (ptr, size); | |
1018 | if (!size) | |
1019 | { | |
1020 | r_alloc_free (ptr); | |
1021 | return r_alloc (ptr, 0); | |
1022 | } | |
1023 | ||
16a5c729 JB |
1024 | bloc = find_bloc (ptr); |
1025 | if (bloc == NIL_BLOC) | |
dcfdbac7 JB |
1026 | abort (); |
1027 | ||
49f82b3d RS |
1028 | if (size < bloc->size) |
1029 | { | |
1030 | /* Wouldn't it be useful to actually resize the bloc here? */ | |
1031 | /* I think so too, but not if it's too expensive... */ | |
1032 | if ((bloc->size - MEM_ROUNDUP (size) >= page_size) | |
1033 | && r_alloc_freeze_level == 0) | |
1034 | { | |
1035 | resize_bloc (bloc, MEM_ROUNDUP (size)); | |
1036 | /* Never mind if this fails, just do nothing... */ | |
1037 | /* It *should* be infallible! */ | |
1038 | } | |
1039 | } | |
1040 | else if (size > bloc->size) | |
1041 | { | |
1042 | if (r_alloc_freeze_level) | |
1043 | { | |
1044 | bloc_ptr new_bloc; | |
1045 | new_bloc = get_bloc (MEM_ROUNDUP (size)); | |
1046 | if (new_bloc) | |
1047 | { | |
1048 | new_bloc->variable = ptr; | |
1049 | *ptr = new_bloc->data; | |
1050 | bloc->variable = (POINTER *) NIL; | |
1051 | } | |
1052 | else | |
1053 | return NIL; | |
1054 | } | |
1055 | else | |
1056 | { | |
1057 | if (! resize_bloc (bloc, MEM_ROUNDUP (size))) | |
1058 | return NIL; | |
1059 | } | |
1060 | } | |
dcfdbac7 JB |
1061 | return *ptr; |
1062 | } | |
81bd58e8 KH |
1063 | |
1064 | /* Disable relocations, after making room for at least SIZE bytes | |
1065 | of non-relocatable heap if possible. The relocatable blocs are | |
1066 | guaranteed to hold still until thawed, even if this means that | |
1067 | malloc must return a null pointer. */ | |
abe9ff32 | 1068 | |
81bd58e8 KH |
1069 | void |
1070 | r_alloc_freeze (size) | |
1071 | long size; | |
1072 | { | |
44d3dec0 RS |
1073 | if (! r_alloc_initialized) |
1074 | r_alloc_init (); | |
1075 | ||
81bd58e8 KH |
1076 | /* If already frozen, we can't make any more room, so don't try. */ |
1077 | if (r_alloc_freeze_level > 0) | |
1078 | size = 0; | |
1079 | /* If we can't get the amount requested, half is better than nothing. */ | |
1080 | while (size > 0 && r_alloc_sbrk (size) == 0) | |
1081 | size /= 2; | |
1082 | ++r_alloc_freeze_level; | |
1083 | if (size > 0) | |
1084 | r_alloc_sbrk (-size); | |
1085 | } | |
1086 | ||
1087 | void | |
1088 | r_alloc_thaw () | |
1089 | { | |
49f82b3d RS |
1090 | |
1091 | if (! r_alloc_initialized) | |
1092 | r_alloc_init (); | |
1093 | ||
81bd58e8 KH |
1094 | if (--r_alloc_freeze_level < 0) |
1095 | abort (); | |
49f82b3d | 1096 | |
8e6208c5 | 1097 | /* This frees all unused blocs. It is not too inefficient, as the resize |
49f82b3d RS |
1098 | and bcopy is done only once. Afterwards, all unreferenced blocs are |
1099 | already shrunk to zero size. */ | |
1100 | if (!r_alloc_freeze_level) | |
1101 | { | |
1102 | bloc_ptr *b = &first_bloc; | |
1103 | while (*b) | |
1104 | if (!(*b)->variable) | |
1105 | free_bloc (*b); | |
1106 | else | |
1107 | b = &(*b)->next; | |
1108 | } | |
81bd58e8 | 1109 | } |
49f82b3d | 1110 | |
dcfdbac7 JB |
1111 | \f |
1112 | /* The hook `malloc' uses for the function which gets more space | |
1113 | from the system. */ | |
1114 | extern POINTER (*__morecore) (); | |
1115 | ||
abe9ff32 | 1116 | /* Initialize various things for memory allocation. */ |
dcfdbac7 | 1117 | |
2c46d29f RS |
1118 | static void |
1119 | r_alloc_init () | |
dcfdbac7 | 1120 | { |
2c46d29f | 1121 | if (r_alloc_initialized) |
dcfdbac7 JB |
1122 | return; |
1123 | ||
2c46d29f | 1124 | r_alloc_initialized = 1; |
bbc60227 | 1125 | real_morecore = __morecore; |
dcfdbac7 | 1126 | __morecore = r_alloc_sbrk; |
8c7f1e35 | 1127 | |
e429caa2 KH |
1128 | first_heap = last_heap = &heap_base; |
1129 | first_heap->next = first_heap->prev = NIL_HEAP; | |
1130 | first_heap->start = first_heap->bloc_start | |
1131 | = virtual_break_value = break_value = (*real_morecore) (0); | |
aef4d570 | 1132 | if (break_value == NIL) |
2c46d29f | 1133 | abort (); |
8c7f1e35 | 1134 | |
7516b7d5 RS |
1135 | page_size = PAGE; |
1136 | extra_bytes = ROUNDUP (50000); | |
1137 | ||
b0119c68 RS |
1138 | #ifdef DOUG_LEA_MALLOC |
1139 | mallopt (M_TOP_PAD, 64 * 4096); | |
1140 | #else | |
49081834 RS |
1141 | /* Give GNU malloc's morecore some hysteresis |
1142 | so that we move all the relocatable blocks much less often. */ | |
1143 | __malloc_extra_blocks = 64; | |
b0119c68 | 1144 | #endif |
49081834 | 1145 | |
e429caa2 | 1146 | first_heap->end = (POINTER) ROUNDUP (first_heap->start); |
0e93a7cf RS |
1147 | |
1148 | /* The extra call to real_morecore guarantees that the end of the | |
1149 | address space is a multiple of page_size, even if page_size is | |
1150 | not really the page size of the system running the binary in | |
1151 | which page_size is stored. This allows a binary to be built on a | |
1152 | system with one page size and run on a system with a smaller page | |
abe9ff32 | 1153 | size. */ |
e429caa2 | 1154 | (*real_morecore) (first_heap->end - first_heap->start); |
0e93a7cf | 1155 | |
2c46d29f RS |
1156 | /* Clear the rest of the last page; this memory is in our address space |
1157 | even though it is after the sbrk value. */ | |
0e93a7cf RS |
1158 | /* Doubly true, with the additional call that explicitly adds the |
1159 | rest of that page to the address space. */ | |
e429caa2 KH |
1160 | bzero (first_heap->start, first_heap->end - first_heap->start); |
1161 | virtual_break_value = break_value = first_heap->bloc_start = first_heap->end; | |
dcfdbac7 | 1162 | use_relocatable_buffers = 1; |
2c46d29f | 1163 | } |
dec41418 RS |
1164 | |
1165 | #if defined (emacs) && defined (DOUG_LEA_MALLOC) | |
1166 | ||
1167 | /* Reinitialize the morecore hook variables after restarting a dumped | |
1168 | Emacs. This is needed when using Doug Lea's malloc from GNU libc. */ | |
1169 | void | |
1170 | r_alloc_reinit () | |
1171 | { | |
1172 | /* Only do this if the hook has been reset, so that we don't get an | |
1173 | infinite loop, in case Emacs was linked statically. */ | |
1174 | if (__morecore != r_alloc_sbrk) | |
1175 | { | |
1176 | real_morecore = __morecore; | |
1177 | __morecore = r_alloc_sbrk; | |
1178 | } | |
1179 | } | |
1180 | #endif | |
1181 | ||
e429caa2 KH |
1182 | #ifdef DEBUG |
1183 | #include <assert.h> | |
1184 | ||
44d3dec0 | 1185 | void |
e429caa2 KH |
1186 | r_alloc_check () |
1187 | { | |
6d16dd06 RS |
1188 | int found = 0; |
1189 | heap_ptr h, ph = 0; | |
1190 | bloc_ptr b, pb = 0; | |
1191 | ||
1192 | if (!r_alloc_initialized) | |
1193 | return; | |
1194 | ||
1195 | assert (first_heap); | |
1196 | assert (last_heap->end <= (POINTER) sbrk (0)); | |
1197 | assert ((POINTER) first_heap < first_heap->start); | |
1198 | assert (first_heap->start <= virtual_break_value); | |
1199 | assert (virtual_break_value <= first_heap->end); | |
1200 | ||
1201 | for (h = first_heap; h; h = h->next) | |
1202 | { | |
1203 | assert (h->prev == ph); | |
1204 | assert ((POINTER) ROUNDUP (h->end) == h->end); | |
40f3f04b RS |
1205 | #if 0 /* ??? The code in ralloc.c does not really try to ensure |
1206 | the heap start has any sort of alignment. | |
1207 | Perhaps it should. */ | |
6d16dd06 | 1208 | assert ((POINTER) MEM_ROUNDUP (h->start) == h->start); |
40f3f04b | 1209 | #endif |
6d16dd06 RS |
1210 | assert ((POINTER) MEM_ROUNDUP (h->bloc_start) == h->bloc_start); |
1211 | assert (h->start <= h->bloc_start && h->bloc_start <= h->end); | |
1212 | ||
1213 | if (ph) | |
1214 | { | |
1215 | assert (ph->end < h->start); | |
1216 | assert (h->start <= (POINTER)h && (POINTER)(h+1) <= h->bloc_start); | |
1217 | } | |
1218 | ||
1219 | if (h->bloc_start <= break_value && break_value <= h->end) | |
1220 | found = 1; | |
1221 | ||
1222 | ph = h; | |
1223 | } | |
1224 | ||
1225 | assert (found); | |
1226 | assert (last_heap == ph); | |
1227 | ||
1228 | for (b = first_bloc; b; b = b->next) | |
1229 | { | |
1230 | assert (b->prev == pb); | |
1231 | assert ((POINTER) MEM_ROUNDUP (b->data) == b->data); | |
1232 | assert ((SIZE) MEM_ROUNDUP (b->size) == b->size); | |
1233 | ||
1234 | ph = 0; | |
1235 | for (h = first_heap; h; h = h->next) | |
1236 | { | |
1237 | if (h->bloc_start <= b->data && b->data + b->size <= h->end) | |
1238 | break; | |
1239 | ph = h; | |
1240 | } | |
1241 | ||
1242 | assert (h); | |
1243 | ||
1244 | if (pb && pb->data + pb->size != b->data) | |
1245 | { | |
1246 | assert (ph && b->data == h->bloc_start); | |
1247 | while (ph) | |
1248 | { | |
1249 | if (ph->bloc_start <= pb->data | |
1250 | && pb->data + pb->size <= ph->end) | |
1251 | { | |
1252 | assert (pb->data + pb->size + b->size > ph->end); | |
1253 | break; | |
1254 | } | |
1255 | else | |
1256 | { | |
1257 | assert (ph->bloc_start + b->size > ph->end); | |
1258 | } | |
1259 | ph = ph->prev; | |
1260 | } | |
1261 | } | |
1262 | pb = b; | |
1263 | } | |
1264 | ||
1265 | assert (last_bloc == pb); | |
1266 | ||
1267 | if (last_bloc) | |
1268 | assert (last_bloc->data + last_bloc->size == break_value); | |
1269 | else | |
1270 | assert (first_heap->bloc_start == break_value); | |
e429caa2 KH |
1271 | } |
1272 | #endif /* DEBUG */ |