Commit | Line | Data |
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dcfdbac7 | 1 | /* Block-relocating memory allocator. |
c6c5df7f | 2 | Copyright (C) 1993 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 | |
8 | the Free Software Foundation; either version 1, or (at your option) | |
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 | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | /* NOTES: | |
21 | ||
eb8c3be9 | 22 | Only relocate the blocs necessary for SIZE in r_alloc_sbrk, |
dcfdbac7 | 23 | rather than all of them. This means allowing for a possible |
abe9ff32 | 24 | hole between the first bloc and the end of malloc storage. */ |
dcfdbac7 | 25 | |
2c46d29f | 26 | #ifdef emacs |
aef4d570 | 27 | |
18160b98 | 28 | #include <config.h> |
956ace37 | 29 | #include "lisp.h" /* Needed for VALBITS. */ |
2c46d29f | 30 | |
aef4d570 RM |
31 | #undef NULL |
32 | ||
f275fd9a RS |
33 | /* The important properties of this type are that 1) it's a pointer, and |
34 | 2) arithmetic on it should work as if the size of the object pointed | |
35 | to has a size of 1. */ | |
a8c0e5ea | 36 | #if 0 /* Arithmetic on void* is a GCC extension. */ |
f275fd9a RS |
37 | #ifdef __STDC__ |
38 | typedef void *POINTER; | |
39 | #else | |
1df181b6 RM |
40 | |
41 | #ifdef HAVE_CONFIG_H | |
42 | #include "config.h" | |
43 | #endif | |
44 | ||
f275fd9a | 45 | typedef char *POINTER; |
1df181b6 | 46 | |
f275fd9a | 47 | #endif |
a8c0e5ea RS |
48 | #endif /* 0 */ |
49 | ||
50 | /* Unconditionally use char * for this. */ | |
51 | typedef char *POINTER; | |
f275fd9a RS |
52 | |
53 | typedef unsigned long SIZE; | |
54 | ||
2c46d29f RS |
55 | /* Declared in dispnew.c, this version doesn't screw up if regions |
56 | overlap. */ | |
57 | extern void safe_bcopy (); | |
2c46d29f | 58 | |
aef4d570 RM |
59 | #include "getpagesize.h" |
60 | ||
61 | #else /* Not emacs. */ | |
62 | ||
2c46d29f | 63 | #include <stddef.h> |
aef4d570 | 64 | |
2c46d29f RS |
65 | typedef size_t SIZE; |
66 | typedef void *POINTER; | |
aef4d570 | 67 | |
aef4d570 RM |
68 | #include <unistd.h> |
69 | #include <malloc.h> | |
70 | #include <string.h> | |
71 | ||
2c46d29f | 72 | #define safe_bcopy(x, y, z) memmove (y, x, z) |
2c46d29f | 73 | |
aef4d570 | 74 | #endif /* emacs. */ |
dcfdbac7 JB |
75 | |
76 | #define NIL ((POINTER) 0) | |
77 | ||
2c46d29f RS |
78 | /* A flag to indicate whether we have initialized ralloc yet. For |
79 | Emacs's sake, please do not make this local to malloc_init; on some | |
80 | machines, the dumping procedure makes all static variables | |
81 | read-only. On these machines, the word static is #defined to be | |
82 | the empty string, meaning that r_alloc_initialized becomes an | |
83 | automatic variable, and loses its value each time Emacs is started up. */ | |
84 | static int r_alloc_initialized = 0; | |
85 | ||
86 | static void r_alloc_init (); | |
dcfdbac7 | 87 | \f |
956ace37 JB |
88 | /* Declarations for working with the malloc, ralloc, and system breaks. */ |
89 | ||
abe9ff32 | 90 | /* Function to set the real break value. */ |
bbc60227 | 91 | static POINTER (*real_morecore) (); |
dcfdbac7 | 92 | |
abe9ff32 | 93 | /* The break value, as seen by malloc. */ |
dcfdbac7 JB |
94 | static POINTER virtual_break_value; |
95 | ||
abe9ff32 RS |
96 | /* The address of the end of the last data in use by ralloc, |
97 | including relocatable blocs as well as malloc data. */ | |
dcfdbac7 JB |
98 | static POINTER break_value; |
99 | ||
7516b7d5 RS |
100 | /* This is the size of a page. We round memory requests to this boundary. */ |
101 | static int page_size; | |
102 | ||
ad3bb3d2 JB |
103 | /* Whenever we get memory from the system, get this many extra bytes. This |
104 | must be a multiple of page_size. */ | |
7516b7d5 RS |
105 | static int extra_bytes; |
106 | ||
dcfdbac7 | 107 | /* Macros for rounding. Note that rounding to any value is possible |
abe9ff32 | 108 | by changing the definition of PAGE. */ |
dcfdbac7 | 109 | #define PAGE (getpagesize ()) |
f7a009a5 RM |
110 | #define ALIGNED(addr) (((unsigned long int) (addr) & (page_size - 1)) == 0) |
111 | #define ROUNDUP(size) (((unsigned long int) (size) + page_size - 1) \ | |
112 | & ~(page_size - 1)) | |
7516b7d5 | 113 | #define ROUND_TO_PAGE(addr) (addr & (~(page_size - 1))) |
e429caa2 KH |
114 | |
115 | #define MEM_ALIGN sizeof(double) | |
116 | #define MEM_ROUNDUP(addr) (((unsigned long int)(addr) + MEM_ALIGN - 1) \ | |
117 | & ~(MEM_ALIGN - 1)) | |
118 | \f | |
abe9ff32 RS |
119 | /* Data structures of heaps and blocs. */ |
120 | ||
121 | /* The relocatable objects, or blocs, and the malloc data | |
122 | both reside within one or more heaps. | |
123 | Each heap contains malloc data, running from `start' to `bloc_start', | |
124 | and relocatable objects, running from `bloc_start' to `free'. | |
125 | ||
126 | Relocatable objects may relocate within the same heap | |
127 | or may move into another heap; the heaps themselves may grow | |
128 | but they never move. | |
129 | ||
130 | We try to make just one heap and make it larger as necessary. | |
131 | But sometimes we can't do that, because we can't get continguous | |
132 | space to add onto the heap. When that happens, we start a new heap. */ | |
133 | ||
e429caa2 KH |
134 | typedef struct heap |
135 | { | |
136 | struct heap *next; | |
137 | struct heap *prev; | |
abe9ff32 | 138 | /* Start of memory range of this heap. */ |
e429caa2 | 139 | POINTER start; |
abe9ff32 | 140 | /* End of memory range of this heap. */ |
e429caa2 | 141 | POINTER end; |
abe9ff32 RS |
142 | /* Start of relocatable data in this heap. */ |
143 | POINTER bloc_start; | |
144 | /* Start of unused space in this heap. */ | |
145 | POINTER free; | |
47f13333 RS |
146 | /* First bloc in this heap. */ |
147 | struct bp *first_bloc; | |
148 | /* Last bloc in this heap. */ | |
149 | struct bp *last_bloc; | |
e429caa2 KH |
150 | } *heap_ptr; |
151 | ||
152 | #define NIL_HEAP ((heap_ptr) 0) | |
153 | #define HEAP_PTR_SIZE (sizeof (struct heap)) | |
154 | ||
abe9ff32 RS |
155 | /* This is the first heap object. |
156 | If we need additional heap objects, each one resides at the beginning of | |
157 | the space it covers. */ | |
158 | static struct heap heap_base; | |
159 | ||
160 | /* Head and tail of the list of heaps. */ | |
e429caa2 KH |
161 | static heap_ptr first_heap, last_heap; |
162 | ||
163 | /* These structures are allocated in the malloc arena. | |
164 | The linked list is kept in order of increasing '.data' members. | |
165 | The data blocks abut each other; if b->next is non-nil, then | |
166 | b->data + b->size == b->next->data. */ | |
167 | typedef struct bp | |
168 | { | |
169 | struct bp *next; | |
170 | struct bp *prev; | |
171 | POINTER *variable; | |
172 | POINTER data; | |
173 | SIZE size; | |
174 | POINTER new_data; /* tmporarily used for relocation */ | |
47f13333 RS |
175 | /* Heap this bloc is in. */ |
176 | struct heap *heap; | |
e429caa2 KH |
177 | } *bloc_ptr; |
178 | ||
179 | #define NIL_BLOC ((bloc_ptr) 0) | |
180 | #define BLOC_PTR_SIZE (sizeof (struct bp)) | |
181 | ||
abe9ff32 | 182 | /* Head and tail of the list of relocatable blocs. */ |
e429caa2 KH |
183 | static bloc_ptr first_bloc, last_bloc; |
184 | ||
dcfdbac7 | 185 | \f |
956ace37 JB |
186 | /* Functions to get and return memory from the system. */ |
187 | ||
abe9ff32 RS |
188 | /* Find the heap that ADDRESS falls within. */ |
189 | ||
190 | static heap_ptr | |
191 | find_heap (address) | |
192 | POINTER address; | |
193 | { | |
194 | heap_ptr heap; | |
195 | ||
196 | for (heap = last_heap; heap; heap = heap->prev) | |
197 | { | |
198 | if (heap->start <= address && address <= heap->end) | |
199 | return heap; | |
200 | } | |
201 | ||
202 | return NIL_HEAP; | |
203 | } | |
204 | ||
205 | /* Find SIZE bytes of space in a heap. | |
206 | Try to get them at ADDRESS (which must fall within some heap's range) | |
207 | if we can get that many within one heap. | |
208 | ||
e429caa2 KH |
209 | If enough space is not presently available in our reserve, this means |
210 | getting more page-aligned space from the system. If the retuned space | |
211 | is not contiguos to the last heap, allocate a new heap, and append it | |
abe9ff32 RS |
212 | |
213 | obtain does not try to keep track of whether space is in use | |
214 | or not in use. It just returns the address of SIZE bytes that | |
215 | fall within a single heap. If you call obtain twice in a row | |
216 | with the same arguments, you typically get the same value. | |
217 | to the heap list. It's the caller's responsibility to keep | |
218 | track of what space is in use. | |
dcfdbac7 | 219 | |
e429caa2 KH |
220 | Return the address of the space if all went well, or zero if we couldn't |
221 | allocate the memory. */ | |
abe9ff32 | 222 | |
e429caa2 KH |
223 | static POINTER |
224 | obtain (address, size) | |
225 | POINTER address; | |
226 | SIZE size; | |
dcfdbac7 | 227 | { |
e429caa2 KH |
228 | heap_ptr heap; |
229 | SIZE already_available; | |
dcfdbac7 | 230 | |
abe9ff32 | 231 | /* Find the heap that ADDRESS falls within. */ |
e429caa2 | 232 | for (heap = last_heap; heap; heap = heap->prev) |
dcfdbac7 | 233 | { |
e429caa2 KH |
234 | if (heap->start <= address && address <= heap->end) |
235 | break; | |
236 | } | |
dcfdbac7 | 237 | |
e429caa2 | 238 | if (! heap) |
abe9ff32 | 239 | abort (); |
dcfdbac7 | 240 | |
abe9ff32 RS |
241 | /* If we can't fit SIZE bytes in that heap, |
242 | try successive later heaps. */ | |
e429caa2 KH |
243 | while (heap && address + size > heap->end) |
244 | { | |
245 | heap = heap->next; | |
246 | if (heap == NIL_HEAP) | |
247 | break; | |
248 | address = heap->bloc_start; | |
dcfdbac7 JB |
249 | } |
250 | ||
abe9ff32 RS |
251 | /* If we can't fit them within any existing heap, |
252 | get more space. */ | |
e429caa2 KH |
253 | if (heap == NIL_HEAP) |
254 | { | |
255 | POINTER new = (*real_morecore)(0); | |
256 | SIZE get; | |
98b7fe02 | 257 | |
e429caa2 | 258 | already_available = (char *)last_heap->end - (char *)address; |
dcfdbac7 | 259 | |
e429caa2 KH |
260 | if (new != last_heap->end) |
261 | { | |
abe9ff32 RS |
262 | /* Someone else called sbrk. Make a new heap. */ |
263 | ||
264 | heap_ptr new_heap = (heap_ptr) MEM_ROUNDUP (new); | |
265 | POINTER bloc_start = (POINTER) MEM_ROUNDUP ((POINTER)(new_heap + 1)); | |
e429caa2 KH |
266 | |
267 | if ((*real_morecore) (bloc_start - new) != new) | |
268 | return 0; | |
269 | ||
270 | new_heap->start = new; | |
271 | new_heap->end = bloc_start; | |
272 | new_heap->bloc_start = bloc_start; | |
abe9ff32 | 273 | new_heap->free = bloc_start; |
e429caa2 KH |
274 | new_heap->next = NIL_HEAP; |
275 | new_heap->prev = last_heap; | |
47f13333 RS |
276 | new_heap->first_bloc = NIL_BLOC; |
277 | new_heap->last_bloc = NIL_BLOC; | |
e429caa2 KH |
278 | last_heap->next = new_heap; |
279 | last_heap = new_heap; | |
280 | ||
281 | address = bloc_start; | |
282 | already_available = 0; | |
283 | } | |
dcfdbac7 | 284 | |
abe9ff32 RS |
285 | /* Add space to the last heap (which we may have just created). |
286 | Get some extra, so we can come here less often. */ | |
287 | ||
e429caa2 | 288 | get = size + extra_bytes - already_available; |
abe9ff32 | 289 | get = (char *) ROUNDUP ((char *)last_heap->end + get) |
e429caa2 | 290 | - (char *) last_heap->end; |
dcfdbac7 | 291 | |
e429caa2 KH |
292 | if ((*real_morecore) (get) != last_heap->end) |
293 | return 0; | |
294 | ||
295 | last_heap->end += get; | |
296 | } | |
297 | ||
298 | return address; | |
299 | } | |
dcfdbac7 | 300 | |
abe9ff32 RS |
301 | /* Return unused heap space to the system |
302 | if there is a lot of unused space now. | |
303 | This can make the last heap smaller; | |
304 | it can also eliminate the last heap entirely. */ | |
305 | ||
dcfdbac7 | 306 | static void |
e429caa2 | 307 | relinquish () |
dcfdbac7 | 308 | { |
e429caa2 KH |
309 | register heap_ptr h; |
310 | int excess = 0; | |
311 | ||
abe9ff32 RS |
312 | /* Add the amount of space beyond break_value |
313 | in all heaps which have extend beyond break_value at all. */ | |
314 | ||
e429caa2 KH |
315 | for (h = last_heap; h && break_value < h->end; h = h->prev) |
316 | { | |
317 | excess += (char *) h->end - (char *) ((break_value < h->bloc_start) | |
318 | ? h->bloc_start : break_value); | |
319 | } | |
320 | ||
321 | if (excess > extra_bytes * 2 && (*real_morecore) (0) == last_heap->end) | |
dcfdbac7 | 322 | { |
7516b7d5 RS |
323 | /* Keep extra_bytes worth of empty space. |
324 | And don't free anything unless we can free at least extra_bytes. */ | |
e429caa2 | 325 | excess -= extra_bytes; |
dcfdbac7 | 326 | |
e429caa2 KH |
327 | if ((char *)last_heap->end - (char *)last_heap->bloc_start <= excess) |
328 | { | |
47f13333 RS |
329 | /* This heap should have no blocs in it. */ |
330 | if (last_heap->first_bloc != NIL_BLOC | |
331 | || last_heap->last_bloc != NIL_BLOC) | |
332 | abort (); | |
333 | ||
abe9ff32 | 334 | /* Return the last heap, with its header, to the system. */ |
e429caa2 KH |
335 | excess = (char *)last_heap->end - (char *)last_heap->start; |
336 | last_heap = last_heap->prev; | |
337 | last_heap->next = NIL_HEAP; | |
338 | } | |
339 | else | |
340 | { | |
341 | excess = (char *) last_heap->end | |
abe9ff32 | 342 | - (char *) ROUNDUP ((char *)last_heap->end - excess); |
e429caa2 KH |
343 | last_heap->end -= excess; |
344 | } | |
dcfdbac7 | 345 | |
e429caa2 KH |
346 | if ((*real_morecore) (- excess) == 0) |
347 | abort (); | |
348 | } | |
dcfdbac7 JB |
349 | } |
350 | \f | |
956ace37 JB |
351 | /* The meat - allocating, freeing, and relocating blocs. */ |
352 | ||
956ace37 | 353 | /* Find the bloc referenced by the address in PTR. Returns a pointer |
abe9ff32 | 354 | to that block. */ |
dcfdbac7 JB |
355 | |
356 | static bloc_ptr | |
357 | find_bloc (ptr) | |
358 | POINTER *ptr; | |
359 | { | |
360 | register bloc_ptr p = first_bloc; | |
361 | ||
362 | while (p != NIL_BLOC) | |
363 | { | |
364 | if (p->variable == ptr && p->data == *ptr) | |
365 | return p; | |
366 | ||
367 | p = p->next; | |
368 | } | |
369 | ||
370 | return p; | |
371 | } | |
372 | ||
373 | /* Allocate a bloc of SIZE bytes and append it to the chain of blocs. | |
98b7fe02 JB |
374 | Returns a pointer to the new bloc, or zero if we couldn't allocate |
375 | memory for the new block. */ | |
dcfdbac7 JB |
376 | |
377 | static bloc_ptr | |
378 | get_bloc (size) | |
379 | SIZE size; | |
380 | { | |
98b7fe02 | 381 | register bloc_ptr new_bloc; |
abe9ff32 | 382 | register heap_ptr heap; |
98b7fe02 JB |
383 | |
384 | if (! (new_bloc = (bloc_ptr) malloc (BLOC_PTR_SIZE)) | |
e429caa2 | 385 | || ! (new_bloc->data = obtain (break_value, size))) |
98b7fe02 JB |
386 | { |
387 | if (new_bloc) | |
388 | free (new_bloc); | |
389 | ||
390 | return 0; | |
391 | } | |
dcfdbac7 | 392 | |
e429caa2 KH |
393 | break_value = new_bloc->data + size; |
394 | ||
dcfdbac7 JB |
395 | new_bloc->size = size; |
396 | new_bloc->next = NIL_BLOC; | |
8c7f1e35 | 397 | new_bloc->variable = (POINTER *) NIL; |
e429caa2 | 398 | new_bloc->new_data = 0; |
dcfdbac7 | 399 | |
abe9ff32 RS |
400 | /* Record in the heap that this space is in use. */ |
401 | heap = find_heap (new_bloc->data); | |
402 | heap->free = break_value; | |
403 | ||
47f13333 RS |
404 | /* Maintain the correspondence between heaps and blocs. */ |
405 | new_bloc->heap = heap; | |
406 | heap->last_bloc = new_bloc; | |
407 | if (heap->first_bloc == NIL_BLOC) | |
408 | heap->first_bloc = new_bloc; | |
409 | ||
abe9ff32 | 410 | /* Put this bloc on the doubly-linked list of blocs. */ |
dcfdbac7 JB |
411 | if (first_bloc) |
412 | { | |
413 | new_bloc->prev = last_bloc; | |
414 | last_bloc->next = new_bloc; | |
415 | last_bloc = new_bloc; | |
416 | } | |
417 | else | |
418 | { | |
419 | first_bloc = last_bloc = new_bloc; | |
420 | new_bloc->prev = NIL_BLOC; | |
421 | } | |
422 | ||
423 | return new_bloc; | |
424 | } | |
47f13333 | 425 | \f |
abe9ff32 RS |
426 | /* Calculate new locations of blocs in the list beginning with BLOC, |
427 | relocating it to start at ADDRESS, in heap HEAP. If enough space is | |
428 | not presently available in our reserve, call obtain for | |
e429caa2 KH |
429 | more space. |
430 | ||
abe9ff32 RS |
431 | Store the new location of each bloc in its new_data field. |
432 | Do not touch the contents of blocs or break_value. */ | |
dcfdbac7 | 433 | |
e429caa2 KH |
434 | static int |
435 | relocate_blocs (bloc, heap, address) | |
436 | bloc_ptr bloc; | |
437 | heap_ptr heap; | |
438 | POINTER address; | |
439 | { | |
440 | register bloc_ptr b = bloc; | |
ad3bb3d2 | 441 | |
e429caa2 KH |
442 | while (b) |
443 | { | |
abe9ff32 RS |
444 | /* If bloc B won't fit within HEAP, |
445 | move to the next heap and try again. */ | |
e429caa2 KH |
446 | while (heap && address + b->size > heap->end) |
447 | { | |
448 | heap = heap->next; | |
449 | if (heap == NIL_HEAP) | |
450 | break; | |
451 | address = heap->bloc_start; | |
452 | } | |
dcfdbac7 | 453 | |
abe9ff32 RS |
454 | /* If BLOC won't fit in any heap, |
455 | get enough new space to hold BLOC and all following blocs. */ | |
e429caa2 KH |
456 | if (heap == NIL_HEAP) |
457 | { | |
458 | register bloc_ptr tb = b; | |
459 | register SIZE s = 0; | |
460 | ||
abe9ff32 | 461 | /* Add up the size of all the following blocs. */ |
e429caa2 KH |
462 | while (tb != NIL_BLOC) |
463 | { | |
464 | s += tb->size; | |
465 | tb = tb->next; | |
466 | } | |
467 | ||
abe9ff32 RS |
468 | /* Get that space. */ |
469 | address = obtain (address, s); | |
470 | if (address == 0) | |
e429caa2 KH |
471 | return 0; |
472 | ||
473 | heap = last_heap; | |
474 | } | |
475 | ||
abe9ff32 RS |
476 | /* Record the new address of this bloc |
477 | and update where the next bloc can start. */ | |
e429caa2 KH |
478 | b->new_data = address; |
479 | address += b->size; | |
480 | b = b->next; | |
481 | } | |
482 | ||
483 | return 1; | |
484 | } | |
485 | ||
47f13333 RS |
486 | /* Reorder the bloc BLOC to go before bloc BEFORE in the doubly linked list. |
487 | This is necessary if we put the memory of space of BLOC | |
488 | before that of BEFORE. */ | |
489 | ||
490 | static void | |
491 | reorder_bloc (bloc, before) | |
492 | bloc_ptr bloc, before; | |
493 | { | |
494 | bloc_ptr prev, next; | |
495 | ||
496 | /* Splice BLOC out from where it is. */ | |
497 | prev = bloc->prev; | |
498 | next = bloc->next; | |
499 | ||
500 | if (prev) | |
501 | prev->next = next; | |
502 | if (next) | |
503 | next->prev = prev; | |
504 | ||
505 | /* Splice it in before BEFORE. */ | |
506 | prev = before->prev; | |
abe9ff32 | 507 | |
47f13333 RS |
508 | if (prev) |
509 | prev->next = bloc; | |
510 | bloc->prev = prev; | |
511 | ||
512 | before->prev = bloc; | |
513 | bloc->next = before; | |
514 | } | |
515 | \f | |
516 | /* Update the records of which heaps contain which blocs, starting | |
517 | with heap HEAP and bloc BLOC. */ | |
518 | ||
519 | static void | |
520 | update_heap_bloc_correspondence (bloc, heap) | |
abe9ff32 RS |
521 | bloc_ptr bloc; |
522 | heap_ptr heap; | |
523 | { | |
524 | register bloc_ptr b; | |
525 | ||
47f13333 RS |
526 | /* Initialize HEAP's status to reflect blocs before BLOC. */ |
527 | if (bloc != NIL_BLOC && bloc->prev != NIL_BLOC && bloc->prev->heap == heap) | |
528 | { | |
529 | /* The previous bloc is in HEAP. */ | |
530 | heap->last_bloc = bloc->prev; | |
531 | heap->free = bloc->prev->data + bloc->prev->size; | |
532 | } | |
533 | else | |
534 | { | |
535 | /* HEAP contains no blocs before BLOC. */ | |
536 | heap->first_bloc = NIL_BLOC; | |
537 | heap->last_bloc = NIL_BLOC; | |
538 | heap->free = heap->bloc_start; | |
539 | } | |
540 | ||
abe9ff32 RS |
541 | /* Advance through blocs one by one. */ |
542 | for (b = bloc; b != NIL_BLOC; b = b->next) | |
543 | { | |
47f13333 RS |
544 | /* Advance through heaps, marking them empty, |
545 | till we get to the one that B is in. */ | |
abe9ff32 RS |
546 | while (heap) |
547 | { | |
548 | if (heap->bloc_start <= b->data && b->data <= heap->end) | |
549 | break; | |
550 | heap = heap->next; | |
47f13333 RS |
551 | /* We know HEAP is not null now, |
552 | because there has to be space for bloc B. */ | |
553 | heap->first_bloc = NIL_BLOC; | |
554 | heap->last_bloc = NIL_BLOC; | |
abe9ff32 RS |
555 | heap->free = heap->bloc_start; |
556 | } | |
47f13333 RS |
557 | |
558 | /* Update HEAP's status for bloc B. */ | |
abe9ff32 | 559 | heap->free = b->data + b->size; |
47f13333 RS |
560 | heap->last_bloc = b; |
561 | if (heap->first_bloc == NIL_BLOC) | |
562 | heap->first_bloc = b; | |
563 | ||
564 | /* Record that B is in HEAP. */ | |
565 | b->heap = heap; | |
abe9ff32 RS |
566 | } |
567 | ||
568 | /* If there are any remaining heaps and no blocs left, | |
47f13333 | 569 | mark those heaps as empty. */ |
abe9ff32 RS |
570 | heap = heap->next; |
571 | while (heap) | |
572 | { | |
47f13333 RS |
573 | heap->first_bloc = NIL_BLOC; |
574 | heap->last_bloc = NIL_BLOC; | |
abe9ff32 RS |
575 | heap->free = heap->bloc_start; |
576 | heap = heap->next; | |
577 | } | |
578 | } | |
47f13333 | 579 | \f |
abe9ff32 RS |
580 | /* Resize BLOC to SIZE bytes. This relocates the blocs |
581 | that come after BLOC in memory. */ | |
582 | ||
e429caa2 KH |
583 | static int |
584 | resize_bloc (bloc, size) | |
585 | bloc_ptr bloc; | |
586 | SIZE size; | |
dcfdbac7 | 587 | { |
e429caa2 KH |
588 | register bloc_ptr b; |
589 | heap_ptr heap; | |
590 | POINTER address; | |
591 | SIZE old_size; | |
592 | ||
593 | if (bloc == NIL_BLOC || size == bloc->size) | |
594 | return 1; | |
595 | ||
596 | for (heap = first_heap; heap != NIL_HEAP; heap = heap->next) | |
597 | { | |
598 | if (heap->bloc_start <= bloc->data && bloc->data <= heap->end) | |
599 | break; | |
600 | } | |
601 | ||
602 | if (heap == NIL_HEAP) | |
abe9ff32 | 603 | abort (); |
e429caa2 KH |
604 | |
605 | old_size = bloc->size; | |
606 | bloc->size = size; | |
607 | ||
abe9ff32 RS |
608 | /* Note that bloc could be moved into the previous heap. */ |
609 | address = (bloc->prev ? bloc->prev->data + bloc->prev->size | |
610 | : first_heap->bloc_start); | |
e429caa2 KH |
611 | while (heap) |
612 | { | |
613 | if (heap->bloc_start <= address && address <= heap->end) | |
614 | break; | |
615 | heap = heap->prev; | |
616 | } | |
617 | ||
618 | if (! relocate_blocs (bloc, heap, address)) | |
619 | { | |
620 | bloc->size = old_size; | |
621 | return 0; | |
622 | } | |
623 | ||
624 | if (size > old_size) | |
625 | { | |
626 | for (b = last_bloc; b != bloc; b = b->prev) | |
627 | { | |
628 | safe_bcopy (b->data, b->new_data, b->size); | |
629 | *b->variable = b->data = b->new_data; | |
630 | } | |
631 | safe_bcopy (bloc->data, bloc->new_data, old_size); | |
632 | bzero (bloc->new_data + old_size, size - old_size); | |
633 | *bloc->variable = bloc->data = bloc->new_data; | |
634 | } | |
635 | else | |
dcfdbac7 | 636 | { |
ad3bb3d2 JB |
637 | for (b = bloc; b != NIL_BLOC; b = b->next) |
638 | { | |
e429caa2 KH |
639 | safe_bcopy (b->data, b->new_data, b->size); |
640 | *b->variable = b->data = b->new_data; | |
ad3bb3d2 | 641 | } |
ad3bb3d2 | 642 | } |
dcfdbac7 | 643 | |
47f13333 | 644 | update_heap_bloc_correspondence (bloc, heap); |
abe9ff32 RS |
645 | |
646 | break_value = (last_bloc ? last_bloc->data + last_bloc->size | |
647 | : first_heap->bloc_start); | |
e429caa2 KH |
648 | return 1; |
649 | } | |
47f13333 | 650 | \f |
abe9ff32 RS |
651 | /* Free BLOC from the chain of blocs, relocating any blocs above it. |
652 | This may return space to the system. */ | |
dcfdbac7 JB |
653 | |
654 | static void | |
655 | free_bloc (bloc) | |
656 | bloc_ptr bloc; | |
657 | { | |
47f13333 RS |
658 | heap_ptr heap = bloc->heap; |
659 | ||
e429caa2 KH |
660 | resize_bloc (bloc, 0); |
661 | ||
dcfdbac7 JB |
662 | if (bloc == first_bloc && bloc == last_bloc) |
663 | { | |
664 | first_bloc = last_bloc = NIL_BLOC; | |
665 | } | |
666 | else if (bloc == last_bloc) | |
667 | { | |
668 | last_bloc = bloc->prev; | |
669 | last_bloc->next = NIL_BLOC; | |
670 | } | |
671 | else if (bloc == first_bloc) | |
672 | { | |
673 | first_bloc = bloc->next; | |
674 | first_bloc->prev = NIL_BLOC; | |
dcfdbac7 JB |
675 | } |
676 | else | |
677 | { | |
678 | bloc->next->prev = bloc->prev; | |
679 | bloc->prev->next = bloc->next; | |
dcfdbac7 JB |
680 | } |
681 | ||
47f13333 RS |
682 | /* Update the records of which blocs are in HEAP. */ |
683 | if (heap->first_bloc == bloc) | |
684 | { | |
685 | if (bloc->next->heap == heap) | |
686 | heap->first_bloc = bloc->next; | |
687 | else | |
688 | heap->first_bloc = heap->last_bloc = NIL_BLOC; | |
689 | } | |
690 | if (heap->last_bloc == bloc) | |
691 | { | |
692 | if (bloc->prev->heap == heap) | |
693 | heap->last_bloc = bloc->prev; | |
694 | else | |
695 | heap->first_bloc = heap->last_bloc = NIL_BLOC; | |
696 | } | |
697 | ||
e429caa2 | 698 | relinquish (); |
dcfdbac7 JB |
699 | free (bloc); |
700 | } | |
701 | \f | |
956ace37 JB |
702 | /* Interface routines. */ |
703 | ||
dcfdbac7 | 704 | static int use_relocatable_buffers; |
81bd58e8 | 705 | static int r_alloc_freeze_level; |
dcfdbac7 | 706 | |
98b7fe02 | 707 | /* Obtain SIZE bytes of storage from the free pool, or the system, as |
2c46d29f | 708 | necessary. If relocatable blocs are in use, this means relocating |
98b7fe02 JB |
709 | them. This function gets plugged into the GNU malloc's __morecore |
710 | hook. | |
711 | ||
7516b7d5 RS |
712 | We provide hysteresis, never relocating by less than extra_bytes. |
713 | ||
98b7fe02 JB |
714 | If we're out of memory, we should return zero, to imitate the other |
715 | __morecore hook values - in particular, __default_morecore in the | |
716 | GNU malloc package. */ | |
dcfdbac7 JB |
717 | |
718 | POINTER | |
719 | r_alloc_sbrk (size) | |
720 | long size; | |
721 | { | |
e429caa2 KH |
722 | register bloc_ptr b; |
723 | POINTER address; | |
dcfdbac7 JB |
724 | |
725 | if (! use_relocatable_buffers) | |
bbc60227 | 726 | return (*real_morecore) (size); |
dcfdbac7 | 727 | |
e429caa2 KH |
728 | if (size == 0) |
729 | return virtual_break_value; | |
7516b7d5 | 730 | |
e429caa2 | 731 | if (size > 0) |
dcfdbac7 | 732 | { |
abe9ff32 RS |
733 | /* Allocate a page-aligned space. GNU malloc would reclaim an |
734 | extra space if we passed an unaligned one. But we could | |
735 | not always find a space which is contiguos to the previous. */ | |
e429caa2 KH |
736 | POINTER new_bloc_start; |
737 | heap_ptr h = first_heap; | |
abe9ff32 | 738 | SIZE get = ROUNDUP (size); |
7516b7d5 | 739 | |
abe9ff32 | 740 | address = (POINTER) ROUNDUP (virtual_break_value); |
e429caa2 | 741 | |
abe9ff32 RS |
742 | /* Search the list upward for a heap which is large enough. */ |
743 | while ((char *) h->end < (char *) MEM_ROUNDUP ((char *)address + get)) | |
e429caa2 KH |
744 | { |
745 | h = h->next; | |
746 | if (h == NIL_HEAP) | |
747 | break; | |
abe9ff32 | 748 | address = (POINTER) ROUNDUP (h->start); |
e429caa2 KH |
749 | } |
750 | ||
abe9ff32 | 751 | /* If not found, obtain more space. */ |
e429caa2 KH |
752 | if (h == NIL_HEAP) |
753 | { | |
754 | get += extra_bytes + page_size; | |
755 | ||
abe9ff32 | 756 | if (r_alloc_freeze_level > 0 || ! obtain (address, get)) |
e429caa2 | 757 | return 0; |
98b7fe02 | 758 | |
e429caa2 | 759 | if (first_heap == last_heap) |
abe9ff32 | 760 | address = (POINTER) ROUNDUP (virtual_break_value); |
e429caa2 | 761 | else |
abe9ff32 | 762 | address = (POINTER) ROUNDUP (last_heap->start); |
e429caa2 KH |
763 | h = last_heap; |
764 | } | |
765 | ||
abe9ff32 | 766 | new_bloc_start = (POINTER) MEM_ROUNDUP ((char *)address + get); |
e429caa2 KH |
767 | |
768 | if (first_heap->bloc_start < new_bloc_start) | |
769 | { | |
abe9ff32 | 770 | /* Move all blocs upward. */ |
e429caa2 KH |
771 | if (r_alloc_freeze_level > 0 |
772 | || ! relocate_blocs (first_bloc, h, new_bloc_start)) | |
773 | return 0; | |
774 | ||
775 | /* Note that (POINTER)(h+1) <= new_bloc_start since | |
776 | get >= page_size, so the following does not destroy the heap | |
abe9ff32 | 777 | header. */ |
e429caa2 KH |
778 | for (b = last_bloc; b != NIL_BLOC; b = b->prev) |
779 | { | |
780 | safe_bcopy (b->data, b->new_data, b->size); | |
781 | *b->variable = b->data = b->new_data; | |
782 | } | |
783 | ||
784 | h->bloc_start = new_bloc_start; | |
abe9ff32 | 785 | |
47f13333 | 786 | update_heap_bloc_correspondence (first_bloc, h); |
e429caa2 | 787 | } |
956ace37 | 788 | |
e429caa2 KH |
789 | if (h != first_heap) |
790 | { | |
791 | /* Give up managing heaps below the one the new | |
abe9ff32 | 792 | virtual_break_value points to. */ |
e429caa2 KH |
793 | first_heap->prev = NIL_HEAP; |
794 | first_heap->next = h->next; | |
795 | first_heap->start = h->start; | |
796 | first_heap->end = h->end; | |
abe9ff32 | 797 | first_heap->free = h->free; |
47f13333 RS |
798 | first_heap->first_bloc = h->first_bloc; |
799 | first_heap->last_bloc = h->last_bloc; | |
e429caa2 KH |
800 | first_heap->bloc_start = h->bloc_start; |
801 | ||
802 | if (first_heap->next) | |
803 | first_heap->next->prev = first_heap; | |
804 | else | |
805 | last_heap = first_heap; | |
806 | } | |
807 | ||
808 | bzero (address, size); | |
dcfdbac7 | 809 | } |
e429caa2 | 810 | else /* size < 0 */ |
dcfdbac7 | 811 | { |
e429caa2 KH |
812 | SIZE excess = (char *)first_heap->bloc_start |
813 | - ((char *)virtual_break_value + size); | |
814 | ||
815 | address = virtual_break_value; | |
816 | ||
817 | if (r_alloc_freeze_level == 0 && excess > 2 * extra_bytes) | |
818 | { | |
819 | excess -= extra_bytes; | |
820 | first_heap->bloc_start | |
47f13333 | 821 | = (POINTER) MEM_ROUNDUP ((char *)first_heap->bloc_start - excess); |
e429caa2 | 822 | |
abe9ff32 | 823 | relocate_blocs (first_bloc, first_heap, first_heap->bloc_start); |
7516b7d5 | 824 | |
e429caa2 KH |
825 | for (b = first_bloc; b != NIL_BLOC; b = b->next) |
826 | { | |
827 | safe_bcopy (b->data, b->new_data, b->size); | |
828 | *b->variable = b->data = b->new_data; | |
829 | } | |
830 | } | |
831 | ||
832 | if ((char *)virtual_break_value + size < (char *)first_heap->start) | |
833 | { | |
834 | /* We found an additional space below the first heap */ | |
835 | first_heap->start = (POINTER) ((char *)virtual_break_value + size); | |
836 | } | |
dcfdbac7 JB |
837 | } |
838 | ||
e429caa2 | 839 | virtual_break_value = (POINTER) ((char *)address + size); |
47f13333 RS |
840 | break_value = (last_bloc |
841 | ? last_bloc->data + last_bloc->size | |
842 | : first_heap->bloc_start); | |
e429caa2 | 843 | if (size < 0) |
abe9ff32 | 844 | relinquish (); |
7516b7d5 | 845 | |
e429caa2 | 846 | return address; |
dcfdbac7 JB |
847 | } |
848 | ||
849 | /* Allocate a relocatable bloc of storage of size SIZE. A pointer to | |
850 | the data is returned in *PTR. PTR is thus the address of some variable | |
98b7fe02 JB |
851 | which will use the data area. |
852 | ||
853 | If we can't allocate the necessary memory, set *PTR to zero, and | |
854 | return zero. */ | |
dcfdbac7 JB |
855 | |
856 | POINTER | |
857 | r_alloc (ptr, size) | |
858 | POINTER *ptr; | |
859 | SIZE size; | |
860 | { | |
861 | register bloc_ptr new_bloc; | |
862 | ||
2c46d29f RS |
863 | if (! r_alloc_initialized) |
864 | r_alloc_init (); | |
865 | ||
abe9ff32 | 866 | new_bloc = get_bloc (MEM_ROUNDUP (size)); |
98b7fe02 JB |
867 | if (new_bloc) |
868 | { | |
869 | new_bloc->variable = ptr; | |
870 | *ptr = new_bloc->data; | |
871 | } | |
872 | else | |
873 | *ptr = 0; | |
dcfdbac7 JB |
874 | |
875 | return *ptr; | |
876 | } | |
877 | ||
2c46d29f RS |
878 | /* Free a bloc of relocatable storage whose data is pointed to by PTR. |
879 | Store 0 in *PTR to show there's no block allocated. */ | |
dcfdbac7 JB |
880 | |
881 | void | |
882 | r_alloc_free (ptr) | |
883 | register POINTER *ptr; | |
884 | { | |
885 | register bloc_ptr dead_bloc; | |
886 | ||
dcfdbac7 JB |
887 | dead_bloc = find_bloc (ptr); |
888 | if (dead_bloc == NIL_BLOC) | |
889 | abort (); | |
890 | ||
891 | free_bloc (dead_bloc); | |
2c46d29f | 892 | *ptr = 0; |
dcfdbac7 JB |
893 | } |
894 | ||
16a5c729 | 895 | /* Given a pointer at address PTR to relocatable data, resize it to SIZE. |
98b7fe02 JB |
896 | Do this by shifting all blocks above this one up in memory, unless |
897 | SIZE is less than or equal to the current bloc size, in which case | |
898 | do nothing. | |
dcfdbac7 | 899 | |
98b7fe02 JB |
900 | Change *PTR to reflect the new bloc, and return this value. |
901 | ||
902 | If more memory cannot be allocated, then leave *PTR unchanged, and | |
903 | return zero. */ | |
dcfdbac7 JB |
904 | |
905 | POINTER | |
906 | r_re_alloc (ptr, size) | |
907 | POINTER *ptr; | |
908 | SIZE size; | |
909 | { | |
16a5c729 | 910 | register bloc_ptr bloc; |
dcfdbac7 | 911 | |
16a5c729 JB |
912 | bloc = find_bloc (ptr); |
913 | if (bloc == NIL_BLOC) | |
dcfdbac7 JB |
914 | abort (); |
915 | ||
16a5c729 | 916 | if (size <= bloc->size) |
956ace37 | 917 | /* Wouldn't it be useful to actually resize the bloc here? */ |
dcfdbac7 JB |
918 | return *ptr; |
919 | ||
abe9ff32 | 920 | if (! resize_bloc (bloc, MEM_ROUNDUP (size))) |
98b7fe02 JB |
921 | return 0; |
922 | ||
dcfdbac7 JB |
923 | return *ptr; |
924 | } | |
81bd58e8 KH |
925 | |
926 | /* Disable relocations, after making room for at least SIZE bytes | |
927 | of non-relocatable heap if possible. The relocatable blocs are | |
928 | guaranteed to hold still until thawed, even if this means that | |
929 | malloc must return a null pointer. */ | |
abe9ff32 | 930 | |
81bd58e8 KH |
931 | void |
932 | r_alloc_freeze (size) | |
933 | long size; | |
934 | { | |
935 | /* If already frozen, we can't make any more room, so don't try. */ | |
936 | if (r_alloc_freeze_level > 0) | |
937 | size = 0; | |
938 | /* If we can't get the amount requested, half is better than nothing. */ | |
939 | while (size > 0 && r_alloc_sbrk (size) == 0) | |
940 | size /= 2; | |
941 | ++r_alloc_freeze_level; | |
942 | if (size > 0) | |
943 | r_alloc_sbrk (-size); | |
944 | } | |
945 | ||
946 | void | |
947 | r_alloc_thaw () | |
948 | { | |
949 | if (--r_alloc_freeze_level < 0) | |
950 | abort (); | |
951 | } | |
dcfdbac7 JB |
952 | \f |
953 | /* The hook `malloc' uses for the function which gets more space | |
954 | from the system. */ | |
955 | extern POINTER (*__morecore) (); | |
956 | ||
abe9ff32 | 957 | /* Initialize various things for memory allocation. */ |
dcfdbac7 | 958 | |
2c46d29f RS |
959 | static void |
960 | r_alloc_init () | |
dcfdbac7 | 961 | { |
e429caa2 KH |
962 | POINTER end; |
963 | ||
2c46d29f | 964 | if (r_alloc_initialized) |
dcfdbac7 JB |
965 | return; |
966 | ||
2c46d29f | 967 | r_alloc_initialized = 1; |
bbc60227 | 968 | real_morecore = __morecore; |
dcfdbac7 | 969 | __morecore = r_alloc_sbrk; |
8c7f1e35 | 970 | |
e429caa2 KH |
971 | first_heap = last_heap = &heap_base; |
972 | first_heap->next = first_heap->prev = NIL_HEAP; | |
973 | first_heap->start = first_heap->bloc_start | |
974 | = virtual_break_value = break_value = (*real_morecore) (0); | |
aef4d570 | 975 | if (break_value == NIL) |
2c46d29f | 976 | abort (); |
8c7f1e35 | 977 | |
7516b7d5 RS |
978 | page_size = PAGE; |
979 | extra_bytes = ROUNDUP (50000); | |
980 | ||
e429caa2 | 981 | first_heap->end = (POINTER) ROUNDUP (first_heap->start); |
0e93a7cf RS |
982 | |
983 | /* The extra call to real_morecore guarantees that the end of the | |
984 | address space is a multiple of page_size, even if page_size is | |
985 | not really the page size of the system running the binary in | |
986 | which page_size is stored. This allows a binary to be built on a | |
987 | system with one page size and run on a system with a smaller page | |
abe9ff32 | 988 | size. */ |
e429caa2 | 989 | (*real_morecore) (first_heap->end - first_heap->start); |
0e93a7cf | 990 | |
2c46d29f RS |
991 | /* Clear the rest of the last page; this memory is in our address space |
992 | even though it is after the sbrk value. */ | |
0e93a7cf RS |
993 | /* Doubly true, with the additional call that explicitly adds the |
994 | rest of that page to the address space. */ | |
e429caa2 KH |
995 | bzero (first_heap->start, first_heap->end - first_heap->start); |
996 | virtual_break_value = break_value = first_heap->bloc_start = first_heap->end; | |
dcfdbac7 | 997 | use_relocatable_buffers = 1; |
2c46d29f | 998 | } |
e429caa2 KH |
999 | #ifdef DEBUG |
1000 | #include <assert.h> | |
1001 | ||
1002 | int | |
1003 | r_alloc_check () | |
1004 | { | |
1005 | int found = 0; | |
1006 | heap_ptr h, ph = 0; | |
1007 | bloc_ptr b, pb = 0; | |
1008 | ||
1009 | if (!r_alloc_initialized) | |
1010 | return; | |
1011 | ||
abe9ff32 RS |
1012 | assert (first_heap); |
1013 | assert (last_heap->end <= (POINTER) sbrk (0)); | |
1014 | assert ((POINTER) first_heap < first_heap->start); | |
1015 | assert (first_heap->start <= virtual_break_value); | |
1016 | assert (virtual_break_value <= first_heap->end); | |
e429caa2 KH |
1017 | |
1018 | for (h = first_heap; h; h = h->next) | |
1019 | { | |
abe9ff32 RS |
1020 | assert (h->prev == ph); |
1021 | assert ((POINTER) ROUNDUP (h->end) == h->end); | |
1022 | assert ((POINTER) MEM_ROUNDUP (h->start) == h->start); | |
1023 | assert ((POINTER) MEM_ROUNDUP (h->bloc_start) == h->bloc_start); | |
1024 | assert (h->start <= h->bloc_start && h->bloc_start <= h->end); | |
e429caa2 KH |
1025 | |
1026 | if (ph) | |
1027 | { | |
1028 | assert (ph->end < h->start); | |
1029 | assert (h->start <= (POINTER)h && (POINTER)(h+1) <= h->bloc_start); | |
1030 | } | |
1031 | ||
1032 | if (h->bloc_start <= break_value && break_value <= h->end) | |
1033 | found = 1; | |
1034 | ||
1035 | ph = h; | |
1036 | } | |
1037 | ||
abe9ff32 RS |
1038 | assert (found); |
1039 | assert (last_heap == ph); | |
e429caa2 KH |
1040 | |
1041 | for (b = first_bloc; b; b = b->next) | |
1042 | { | |
abe9ff32 RS |
1043 | assert (b->prev == pb); |
1044 | assert ((POINTER) MEM_ROUNDUP (b->data) == b->data); | |
1045 | assert ((SIZE) MEM_ROUNDUP (b->size) == b->size); | |
e429caa2 KH |
1046 | |
1047 | ph = 0; | |
1048 | for (h = first_heap; h; h = h->next) | |
1049 | { | |
1050 | if (h->bloc_start <= b->data && b->data + b->size <= h->end) | |
1051 | break; | |
1052 | ph = h; | |
1053 | } | |
1054 | ||
abe9ff32 | 1055 | assert (h); |
e429caa2 KH |
1056 | |
1057 | if (pb && pb->data + pb->size != b->data) | |
1058 | { | |
abe9ff32 | 1059 | assert (ph && b->data == h->bloc_start); |
e429caa2 KH |
1060 | while (ph) |
1061 | { | |
1062 | if (ph->bloc_start <= pb->data | |
1063 | && pb->data + pb->size <= ph->end) | |
1064 | { | |
abe9ff32 | 1065 | assert (pb->data + pb->size + b->size > ph->end); |
e429caa2 KH |
1066 | break; |
1067 | } | |
1068 | else | |
1069 | { | |
abe9ff32 | 1070 | assert (ph->bloc_start + b->size > ph->end); |
e429caa2 KH |
1071 | } |
1072 | ph = ph->prev; | |
1073 | } | |
1074 | } | |
1075 | pb = b; | |
1076 | } | |
1077 | ||
abe9ff32 | 1078 | assert (last_bloc == pb); |
e429caa2 KH |
1079 | |
1080 | if (last_bloc) | |
abe9ff32 | 1081 | assert (last_bloc->data + last_bloc->size == break_value); |
e429caa2 | 1082 | else |
abe9ff32 | 1083 | assert (first_heap->bloc_start == break_value); |
e429caa2 KH |
1084 | } |
1085 | #endif /* DEBUG */ |