source: trunk/src/gcc/boehm-gc/mallocx.c@ 2013

Last change on this file since 2013 was 2, checked in by bird, 22 years ago

Initial revision
  • Property cvs2svn:cvs-rev set to 1.1
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 18.2 KB
Line 
1/*
2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
4 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
5 * Copyright (c) 2000 by Hewlett-Packard Company. All rights reserved.
6 *
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
9 *
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
15 */
16
17/*
18 * These are extra allocation routines which are likely to be less
19 * frequently used than those in malloc.c. They are separate in the
20 * hope that the .o file will be excluded from statically linked
21 * executables. We should probably break this up further.
22 */
23
24#include <stdio.h>
25#include "private/gc_priv.h"
26
27extern ptr_t GC_clear_stack(); /* in misc.c, behaves like identity */
28void GC_extend_size_map(); /* in misc.c. */
29GC_bool GC_alloc_reclaim_list(); /* in malloc.c */
30
31/* Some externally visible but unadvertised variables to allow access to */
32/* free lists from inlined allocators without including gc_priv.h */
33/* or introducing dependencies on internal data structure layouts. */
34ptr_t * GC_CONST GC_objfreelist_ptr = GC_objfreelist;
35ptr_t * GC_CONST GC_aobjfreelist_ptr = GC_aobjfreelist;
36ptr_t * GC_CONST GC_uobjfreelist_ptr = GC_uobjfreelist;
37# ifdef ATOMIC_UNCOLLECTABLE
38 ptr_t * GC_CONST GC_auobjfreelist_ptr = GC_auobjfreelist;
39# endif
40
41
42GC_PTR GC_generic_or_special_malloc(lb,knd)
43word lb;
44int knd;
45{
46 switch(knd) {
47# ifdef STUBBORN_ALLOC
48 case STUBBORN:
49 return(GC_malloc_stubborn((size_t)lb));
50# endif
51 case PTRFREE:
52 return(GC_malloc_atomic((size_t)lb));
53 case NORMAL:
54 return(GC_malloc((size_t)lb));
55 case UNCOLLECTABLE:
56 return(GC_malloc_uncollectable((size_t)lb));
57# ifdef ATOMIC_UNCOLLECTABLE
58 case AUNCOLLECTABLE:
59 return(GC_malloc_atomic_uncollectable((size_t)lb));
60# endif /* ATOMIC_UNCOLLECTABLE */
61 default:
62 return(GC_generic_malloc(lb,knd));
63 }
64}
65
66
67/* Change the size of the block pointed to by p to contain at least */
68/* lb bytes. The object may be (and quite likely will be) moved. */
69/* The kind (e.g. atomic) is the same as that of the old. */
70/* Shrinking of large blocks is not implemented well. */
71# ifdef __STDC__
72 GC_PTR GC_realloc(GC_PTR p, size_t lb)
73# else
74 GC_PTR GC_realloc(p,lb)
75 GC_PTR p;
76 size_t lb;
77# endif
78{
79register struct hblk * h;
80register hdr * hhdr;
81register word sz; /* Current size in bytes */
82register word orig_sz; /* Original sz in bytes */
83int obj_kind;
84
85 if (p == 0) return(GC_malloc(lb)); /* Required by ANSI */
86 h = HBLKPTR(p);
87 hhdr = HDR(h);
88 sz = hhdr -> hb_sz;
89 obj_kind = hhdr -> hb_obj_kind;
90 sz = WORDS_TO_BYTES(sz);
91 orig_sz = sz;
92
93 if (sz > MAXOBJBYTES) {
94 /* Round it up to the next whole heap block */
95 register word descr;
96
97 sz = (sz+HBLKSIZE-1) & (~HBLKMASK);
98 hhdr -> hb_sz = BYTES_TO_WORDS(sz);
99 descr = GC_obj_kinds[obj_kind].ok_descriptor;
100 if (GC_obj_kinds[obj_kind].ok_relocate_descr) descr += sz;
101 hhdr -> hb_descr = descr;
102 if (IS_UNCOLLECTABLE(obj_kind)) GC_non_gc_bytes += (sz - orig_sz);
103 /* Extra area is already cleared by GC_alloc_large_and_clear. */
104 }
105 if (ADD_SLOP(lb) <= sz) {
106 if (lb >= (sz >> 1)) {
107# ifdef STUBBORN_ALLOC
108 if (obj_kind == STUBBORN) GC_change_stubborn(p);
109# endif
110 if (orig_sz > lb) {
111 /* Clear unneeded part of object to avoid bogus pointer */
112 /* tracing. */
113 /* Safe for stubborn objects. */
114 BZERO(((ptr_t)p) + lb, orig_sz - lb);
115 }
116 return(p);
117 } else {
118 /* shrink */
119 GC_PTR result =
120 GC_generic_or_special_malloc((word)lb, obj_kind);
121
122 if (result == 0) return(0);
123 /* Could also return original object. But this */
124 /* gives the client warning of imminent disaster. */
125 BCOPY(p, result, lb);
126# ifndef IGNORE_FREE
127 GC_free(p);
128# endif
129 return(result);
130 }
131 } else {
132 /* grow */
133 GC_PTR result =
134 GC_generic_or_special_malloc((word)lb, obj_kind);
135
136 if (result == 0) return(0);
137 BCOPY(p, result, sz);
138# ifndef IGNORE_FREE
139 GC_free(p);
140# endif
141 return(result);
142 }
143}
144
145# if defined(REDIRECT_MALLOC) || defined(REDIRECT_REALLOC)
146# ifdef __STDC__
147 GC_PTR realloc(GC_PTR p, size_t lb)
148# else
149 GC_PTR realloc(p,lb)
150 GC_PTR p;
151 size_t lb;
152# endif
153 {
154# ifdef REDIRECT_REALLOC
155 return(REDIRECT_REALLOC(p, lb));
156# else
157 return(GC_realloc(p, lb));
158# endif
159 }
160# endif /* REDIRECT_MALLOC */
161
162
163/* The same thing, except caller does not hold allocation lock. */
164/* We avoid holding allocation lock while we clear memory. */
165ptr_t GC_generic_malloc_ignore_off_page(lb, k)
166register size_t lb;
167register int k;
168{
169 register ptr_t result;
170 word lw;
171 word n_blocks;
172 GC_bool init;
173 DCL_LOCK_STATE;
174
175 if (SMALL_OBJ(lb))
176 return(GC_generic_malloc((word)lb, k));
177 lw = ROUNDED_UP_WORDS(lb);
178 n_blocks = OBJ_SZ_TO_BLOCKS(lw);
179 init = GC_obj_kinds[k].ok_init;
180 GC_INVOKE_FINALIZERS();
181 DISABLE_SIGNALS();
182 LOCK();
183 result = (ptr_t)GC_alloc_large(lw, k, IGNORE_OFF_PAGE);
184 if (0 != result) {
185 if (GC_debugging_started) {
186 BZERO(result, n_blocks * HBLKSIZE);
187 } else {
188# ifdef THREADS
189 /* Clear any memory that might be used for GC descriptors */
190 /* before we release the lock. */
191 ((word *)result)[0] = 0;
192 ((word *)result)[1] = 0;
193 ((word *)result)[lw-1] = 0;
194 ((word *)result)[lw-2] = 0;
195# endif
196 }
197 }
198 GC_words_allocd += lw;
199 UNLOCK();
200 ENABLE_SIGNALS();
201 if (0 == result) {
202 return((*GC_oom_fn)(lb));
203 } else {
204 if (init & !GC_debugging_started) {
205 BZERO(result, n_blocks * HBLKSIZE);
206 }
207 return(result);
208 }
209}
210
211# if defined(__STDC__) || defined(__cplusplus)
212 void * GC_malloc_ignore_off_page(size_t lb)
213# else
214 char * GC_malloc_ignore_off_page(lb)
215 register size_t lb;
216# endif
217{
218 return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, NORMAL));
219}
220
221# if defined(__STDC__) || defined(__cplusplus)
222 void * GC_malloc_atomic_ignore_off_page(size_t lb)
223# else
224 char * GC_malloc_atomic_ignore_off_page(lb)
225 register size_t lb;
226# endif
227{
228 return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, PTRFREE));
229}
230
231/* Increment GC_words_allocd from code that doesn't have direct access */
232/* to GC_arrays. */
233# ifdef __STDC__
234void GC_incr_words_allocd(size_t n)
235{
236 GC_words_allocd += n;
237}
238
239/* The same for GC_mem_freed. */
240void GC_incr_mem_freed(size_t n)
241{
242 GC_mem_freed += n;
243}
244# endif /* __STDC__ */
245
246/* Analogous to the above, but assumes a small object size, and */
247/* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
248ptr_t GC_generic_malloc_words_small_inner(lw, k)
249register word lw;
250register int k;
251{
252register ptr_t op;
253register ptr_t *opp;
254register struct obj_kind * kind = GC_obj_kinds + k;
255
256 opp = &(kind -> ok_freelist[lw]);
257 if( (op = *opp) == 0 ) {
258 if (!GC_is_initialized) {
259 GC_init_inner();
260 }
261 if (kind -> ok_reclaim_list != 0 || GC_alloc_reclaim_list(kind)) {
262 op = GC_clear_stack(GC_allocobj((word)lw, k));
263 }
264 if (op == 0) {
265 UNLOCK();
266 ENABLE_SIGNALS();
267 return ((*GC_oom_fn)(WORDS_TO_BYTES(lw)));
268 }
269 }
270 *opp = obj_link(op);
271 obj_link(op) = 0;
272 GC_words_allocd += lw;
273 return((ptr_t)op);
274}
275
276/* Analogous to the above, but assumes a small object size, and */
277/* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
278#ifdef __STDC__
279 ptr_t GC_generic_malloc_words_small(size_t lw, int k)
280#else
281 ptr_t GC_generic_malloc_words_small(lw, k)
282 register word lw;
283 register int k;
284#endif
285{
286register ptr_t op;
287DCL_LOCK_STATE;
288
289 GC_INVOKE_FINALIZERS();
290 DISABLE_SIGNALS();
291 LOCK();
292 op = GC_generic_malloc_words_small_inner(lw, k);
293 UNLOCK();
294 ENABLE_SIGNALS();
295 return((ptr_t)op);
296}
297
298#if defined(THREADS) && !defined(SRC_M3)
299
300extern signed_word GC_mem_found; /* Protected by GC lock. */
301
302#ifdef PARALLEL_MARK
303volatile signed_word GC_words_allocd_tmp = 0;
304 /* Number of words of memory allocated since */
305 /* we released the GC lock. Instead of */
306 /* reacquiring the GC lock just to add this in, */
307 /* we add it in the next time we reacquire */
308 /* the lock. (Atomically adding it doesn't */
309 /* work, since we would have to atomically */
310 /* update it in GC_malloc, which is too */
311 /* expensive. */
312#endif /* PARALLEL_MARK */
313
314/* See reclaim.c: */
315extern ptr_t GC_reclaim_generic();
316
317/* Return a list of 1 or more objects of the indicated size, linked */
318/* through the first word in the object. This has the advantage that */
319/* it acquires the allocation lock only once, and may greatly reduce */
320/* time wasted contending for the allocation lock. Typical usage would */
321/* be in a thread that requires many items of the same size. It would */
322/* keep its own free list in thread-local storage, and call */
323/* GC_malloc_many or friends to replenish it. (We do not round up */
324/* object sizes, since a call indicates the intention to consume many */
325/* objects of exactly this size.) */
326/* We return the free-list by assigning it to *result, since it is */
327/* not safe to return, e.g. a linked list of pointer-free objects, */
328/* since the collector would not retain the entire list if it were */
329/* invoked just as we were returning. */
330/* Note that the client should usually clear the link field. */
331void GC_generic_malloc_many(lb, k, result)
332register word lb;
333register int k;
334ptr_t *result;
335{
336ptr_t op;
337ptr_t p;
338ptr_t *opp;
339word lw;
340word my_words_allocd = 0;
341struct obj_kind * ok = &(GC_obj_kinds[k]);
342DCL_LOCK_STATE;
343
344# if defined(GATHERSTATS) || defined(PARALLEL_MARK)
345# define COUNT_ARG , &my_words_allocd
346# else
347# define COUNT_ARG
348# define NEED_TO_COUNT
349# endif
350 if (!SMALL_OBJ(lb)) {
351 op = GC_generic_malloc(lb, k);
352 if(0 != op) obj_link(op) = 0;
353 *result = op;
354 return;
355 }
356 lw = ALIGNED_WORDS(lb);
357 GC_INVOKE_FINALIZERS();
358 DISABLE_SIGNALS();
359 LOCK();
360 if (!GC_is_initialized) GC_init_inner();
361 /* Do our share of marking work */
362 if (GC_incremental && !GC_dont_gc) {
363 ENTER_GC();
364 GC_collect_a_little_inner(1);
365 EXIT_GC();
366 }
367 /* First see if we can reclaim a page of objects waiting to be */
368 /* reclaimed. */
369 {
370 struct hblk ** rlh = ok -> ok_reclaim_list;
371 struct hblk * hbp;
372 hdr * hhdr;
373
374 rlh += lw;
375 while ((hbp = *rlh) != 0) {
376 hhdr = HDR(hbp);
377 *rlh = hhdr -> hb_next;
378# ifdef PARALLEL_MARK
379 {
380 signed_word my_words_allocd_tmp = GC_words_allocd_tmp;
381
382 GC_ASSERT(my_words_allocd_tmp >= 0);
383 /* We only decrement it while holding the GC lock. */
384 /* Thus we can't accidentally adjust it down in more */
385 /* than one thread simultaneously. */
386 if (my_words_allocd_tmp != 0) {
387 (void)GC_atomic_add(
388 (volatile GC_word *)(&GC_words_allocd_tmp),
389 (GC_word)(-my_words_allocd_tmp));
390 GC_words_allocd += my_words_allocd_tmp;
391 }
392 }
393 GC_acquire_mark_lock();
394 ++ GC_fl_builder_count;
395 UNLOCK();
396 ENABLE_SIGNALS();
397 GC_release_mark_lock();
398# endif
399 op = GC_reclaim_generic(hbp, hhdr, lw,
400 ok -> ok_init, 0 COUNT_ARG);
401 if (op != 0) {
402# ifdef NEED_TO_COUNT
403 /* We are neither gathering statistics, nor marking in */
404 /* parallel. Thus GC_reclaim_generic doesn't count */
405 /* for us. */
406 for (p = op; p != 0; p = obj_link(p)) {
407 my_words_allocd += lw;
408 }
409# endif
410# if defined(GATHERSTATS)
411 /* We also reclaimed memory, so we need to adjust */
412 /* that count. */
413 /* This should be atomic, so the results may be */
414 /* inaccurate. */
415 GC_mem_found += my_words_allocd;
416# endif
417# ifdef PARALLEL_MARK
418 *result = op;
419 (void)GC_atomic_add(
420 (volatile GC_word *)(&GC_words_allocd_tmp),
421 (GC_word)(my_words_allocd));
422 GC_acquire_mark_lock();
423 -- GC_fl_builder_count;
424 if (GC_fl_builder_count == 0) GC_notify_all_builder();
425 GC_release_mark_lock();
426 (void) GC_clear_stack(0);
427 return;
428# else
429 GC_words_allocd += my_words_allocd;
430 goto out;
431# endif
432 }
433# ifdef PARALLEL_MARK
434 GC_acquire_mark_lock();
435 -- GC_fl_builder_count;
436 if (GC_fl_builder_count == 0) GC_notify_all_builder();
437 GC_release_mark_lock();
438 DISABLE_SIGNALS();
439 LOCK();
440 /* GC lock is needed for reclaim list access. We */
441 /* must decrement fl_builder_count before reaquiring GC */
442 /* lock. Hopefully this path is rare. */
443# endif
444 }
445 }
446 /* Next try to use prefix of global free list if there is one. */
447 /* We don't refill it, but we need to use it up before allocating */
448 /* a new block ourselves. */
449 opp = &(GC_obj_kinds[k].ok_freelist[lw]);
450 if ( (op = *opp) != 0 ) {
451 *opp = 0;
452 my_words_allocd = 0;
453 for (p = op; p != 0; p = obj_link(p)) {
454 my_words_allocd += lw;
455 if (my_words_allocd >= BODY_SZ) {
456 *opp = obj_link(p);
457 obj_link(p) = 0;
458 break;
459 }
460 }
461 GC_words_allocd += my_words_allocd;
462 goto out;
463 }
464 /* Next try to allocate a new block worth of objects of this size. */
465 {
466 struct hblk *h = GC_allochblk(lw, k, 0);
467 if (h != 0) {
468 if (IS_UNCOLLECTABLE(k)) GC_set_hdr_marks(HDR(h));
469 GC_words_allocd += BYTES_TO_WORDS(HBLKSIZE)
470 - BYTES_TO_WORDS(HBLKSIZE) % lw;
471# ifdef PARALLEL_MARK
472 GC_acquire_mark_lock();
473 ++ GC_fl_builder_count;
474 UNLOCK();
475 ENABLE_SIGNALS();
476 GC_release_mark_lock();
477# endif
478
479 op = GC_build_fl(h, lw, ok -> ok_init, 0);
480# ifdef PARALLEL_MARK
481 *result = op;
482 GC_acquire_mark_lock();
483 -- GC_fl_builder_count;
484 if (GC_fl_builder_count == 0) GC_notify_all_builder();
485 GC_release_mark_lock();
486 (void) GC_clear_stack(0);
487 return;
488# else
489 goto out;
490# endif
491 }
492 }
493
494 /* As a last attempt, try allocating a single object. Note that */
495 /* this may trigger a collection or expand the heap. */
496 op = GC_generic_malloc_inner(lb, k);
497 if (0 != op) obj_link(op) = 0;
498
499 out:
500 *result = op;
501 UNLOCK();
502 ENABLE_SIGNALS();
503 (void) GC_clear_stack(0);
504}
505
506GC_PTR GC_malloc_many(size_t lb)
507{
508 ptr_t result;
509 GC_generic_malloc_many(lb, NORMAL, &result);
510 return result;
511}
512
513/* Note that the "atomic" version of this would be unsafe, since the */
514/* links would not be seen by the collector. */
515# endif
516
517/* Allocate lb bytes of pointerful, traced, but not collectable data */
518# ifdef __STDC__
519 GC_PTR GC_malloc_uncollectable(size_t lb)
520# else
521 GC_PTR GC_malloc_uncollectable(lb)
522 size_t lb;
523# endif
524{
525register ptr_t op;
526register ptr_t *opp;
527register word lw;
528DCL_LOCK_STATE;
529
530 if( SMALL_OBJ(lb) ) {
531# ifdef MERGE_SIZES
532 if (EXTRA_BYTES != 0 && lb != 0) lb--;
533 /* We don't need the extra byte, since this won't be */
534 /* collected anyway. */
535 lw = GC_size_map[lb];
536# else
537 lw = ALIGNED_WORDS(lb);
538# endif
539 opp = &(GC_uobjfreelist[lw]);
540 FASTLOCK();
541 if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
542 /* See above comment on signals. */
543 *opp = obj_link(op);
544 obj_link(op) = 0;
545 GC_words_allocd += lw;
546 /* Mark bit ws already set on free list. It will be */
547 /* cleared only temporarily during a collection, as a */
548 /* result of the normal free list mark bit clearing. */
549 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
550 FASTUNLOCK();
551 return((GC_PTR) op);
552 }
553 FASTUNLOCK();
554 op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
555 } else {
556 op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
557 }
558 if (0 == op) return(0);
559 /* We don't need the lock here, since we have an undisguised */
560 /* pointer. We do need to hold the lock while we adjust */
561 /* mark bits. */
562 {
563 register struct hblk * h;
564
565 h = HBLKPTR(op);
566 lw = HDR(h) -> hb_sz;
567
568 DISABLE_SIGNALS();
569 LOCK();
570 GC_set_mark_bit(op);
571 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
572 UNLOCK();
573 ENABLE_SIGNALS();
574 return((GC_PTR) op);
575 }
576}
577
578# ifdef ATOMIC_UNCOLLECTABLE
579/* Allocate lb bytes of pointerfree, untraced, uncollectable data */
580/* This is normally roughly equivalent to the system malloc. */
581/* But it may be useful if malloc is redefined. */
582# ifdef __STDC__
583 GC_PTR GC_malloc_atomic_uncollectable(size_t lb)
584# else
585 GC_PTR GC_malloc_atomic_uncollectable(lb)
586 size_t lb;
587# endif
588{
589register ptr_t op;
590register ptr_t *opp;
591register word lw;
592DCL_LOCK_STATE;
593
594 if( SMALL_OBJ(lb) ) {
595# ifdef MERGE_SIZES
596 if (EXTRA_BYTES != 0 && lb != 0) lb--;
597 /* We don't need the extra byte, since this won't be */
598 /* collected anyway. */
599 lw = GC_size_map[lb];
600# else
601 lw = ALIGNED_WORDS(lb);
602# endif
603 opp = &(GC_auobjfreelist[lw]);
604 FASTLOCK();
605 if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
606 /* See above comment on signals. */
607 *opp = obj_link(op);
608 obj_link(op) = 0;
609 GC_words_allocd += lw;
610 /* Mark bit was already set while object was on free list. */
611 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
612 FASTUNLOCK();
613 return((GC_PTR) op);
614 }
615 FASTUNLOCK();
616 op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
617 } else {
618 op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
619 }
620 if (0 == op) return(0);
621 /* We don't need the lock here, since we have an undisguised */
622 /* pointer. We do need to hold the lock while we adjust */
623 /* mark bits. */
624 {
625 register struct hblk * h;
626
627 h = HBLKPTR(op);
628 lw = HDR(h) -> hb_sz;
629
630 DISABLE_SIGNALS();
631 LOCK();
632 GC_set_mark_bit(op);
633 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
634 UNLOCK();
635 ENABLE_SIGNALS();
636 return((GC_PTR) op);
637 }
638}
639
640#endif /* ATOMIC_UNCOLLECTABLE */
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