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
27 extern ptr_t GC_clear_stack(); /* in misc.c, behaves like identity */
28 void GC_extend_size_map(); /* in misc.c. */
29 GC_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. */
34 ptr_t * GC_CONST GC_objfreelist_ptr = GC_objfreelist;
35 ptr_t * GC_CONST GC_aobjfreelist_ptr = GC_aobjfreelist;
36 ptr_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
GC_generic_or_special_malloc(lb,knd)42 GC_PTR GC_generic_or_special_malloc(lb,knd)
43 word lb;
44 int 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__
GC_realloc(GC_PTR p,size_t lb)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 {
79 register struct hblk * h;
80 register hdr * hhdr;
81 register word sz; /* Current size in bytes */
82 register word orig_sz; /* Original sz in bytes */
83 int 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 # define REDIRECT_REALLOC GC_realloc
147 # endif
148
149 # ifdef REDIRECT_REALLOC
150
151 /* As with malloc, avoid two levels of extra calls here. */
152 # ifdef GC_ADD_CALLER
153 # define RA GC_RETURN_ADDR,
154 # else
155 # define RA
156 # endif
157 # define GC_debug_realloc_replacement(p, lb) \
158 GC_debug_realloc(p, lb, RA "unknown", 0)
159
160 # ifdef __STDC__
realloc(GC_PTR p,size_t lb)161 GC_PTR realloc(GC_PTR p, size_t lb)
162 # else
163 GC_PTR realloc(p,lb)
164 GC_PTR p;
165 size_t lb;
166 # endif
167 {
168 return(REDIRECT_REALLOC(p, lb));
169 }
170
171 # undef GC_debug_realloc_replacement
172 # endif /* REDIRECT_REALLOC */
173
174
175 /* Allocate memory such that only pointers to near the */
176 /* beginning of the object are considered. */
177 /* We avoid holding allocation lock while we clear memory. */
GC_generic_malloc_ignore_off_page(lb,k)178 ptr_t GC_generic_malloc_ignore_off_page(lb, k)
179 register size_t lb;
180 register int k;
181 {
182 register ptr_t result;
183 word lw;
184 word n_blocks;
185 GC_bool init;
186 DCL_LOCK_STATE;
187
188 if (SMALL_OBJ(lb))
189 return(GC_generic_malloc((word)lb, k));
190 lw = ROUNDED_UP_WORDS(lb);
191 n_blocks = OBJ_SZ_TO_BLOCKS(lw);
192 init = GC_obj_kinds[k].ok_init;
193 if (GC_have_errors) GC_print_all_errors();
194 GC_INVOKE_FINALIZERS();
195 DISABLE_SIGNALS();
196 LOCK();
197 result = (ptr_t)GC_alloc_large(lw, k, IGNORE_OFF_PAGE);
198 if (0 != result) {
199 if (GC_debugging_started) {
200 BZERO(result, n_blocks * HBLKSIZE);
201 } else {
202 # ifdef THREADS
203 /* Clear any memory that might be used for GC descriptors */
204 /* before we release the lock. */
205 ((word *)result)[0] = 0;
206 ((word *)result)[1] = 0;
207 ((word *)result)[lw-1] = 0;
208 ((word *)result)[lw-2] = 0;
209 # endif
210 }
211 }
212 GC_words_allocd += lw;
213 UNLOCK();
214 ENABLE_SIGNALS();
215 if (0 == result) {
216 return((*GC_oom_fn)(lb));
217 } else {
218 if (init && !GC_debugging_started) {
219 BZERO(result, n_blocks * HBLKSIZE);
220 }
221 return(result);
222 }
223 }
224
225 # if defined(__STDC__) || defined(__cplusplus)
GC_malloc_ignore_off_page(size_t lb)226 void * GC_malloc_ignore_off_page(size_t lb)
227 # else
228 char * GC_malloc_ignore_off_page(lb)
229 register size_t lb;
230 # endif
231 {
232 return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, NORMAL));
233 }
234
235 # if defined(__STDC__) || defined(__cplusplus)
GC_malloc_atomic_ignore_off_page(size_t lb)236 void * GC_malloc_atomic_ignore_off_page(size_t lb)
237 # else
238 char * GC_malloc_atomic_ignore_off_page(lb)
239 register size_t lb;
240 # endif
241 {
242 return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, PTRFREE));
243 }
244
245 /* Increment GC_words_allocd from code that doesn't have direct access */
246 /* to GC_arrays. */
247 # ifdef __STDC__
GC_incr_words_allocd(size_t n)248 void GC_incr_words_allocd(size_t n)
249 {
250 GC_words_allocd += n;
251 }
252
253 /* The same for GC_mem_freed. */
GC_incr_mem_freed(size_t n)254 void GC_incr_mem_freed(size_t n)
255 {
256 GC_mem_freed += n;
257 }
258 # endif /* __STDC__ */
259
260 /* Analogous to the above, but assumes a small object size, and */
261 /* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
GC_generic_malloc_words_small_inner(lw,k)262 ptr_t GC_generic_malloc_words_small_inner(lw, k)
263 register word lw;
264 register int k;
265 {
266 register ptr_t op;
267 register ptr_t *opp;
268 register struct obj_kind * kind = GC_obj_kinds + k;
269
270 opp = &(kind -> ok_freelist[lw]);
271 if( (op = *opp) == 0 ) {
272 if (!GC_is_initialized) {
273 GC_init_inner();
274 }
275 if (kind -> ok_reclaim_list != 0 || GC_alloc_reclaim_list(kind)) {
276 op = GC_clear_stack(GC_allocobj((word)lw, k));
277 }
278 if (op == 0) {
279 UNLOCK();
280 ENABLE_SIGNALS();
281 return ((*GC_oom_fn)(WORDS_TO_BYTES(lw)));
282 }
283 }
284 *opp = obj_link(op);
285 obj_link(op) = 0;
286 GC_words_allocd += lw;
287 return((ptr_t)op);
288 }
289
290 /* Analogous to the above, but assumes a small object size, and */
291 /* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
292 #ifdef __STDC__
GC_generic_malloc_words_small(size_t lw,int k)293 ptr_t GC_generic_malloc_words_small(size_t lw, int k)
294 #else
295 ptr_t GC_generic_malloc_words_small(lw, k)
296 register word lw;
297 register int k;
298 #endif
299 {
300 register ptr_t op;
301 DCL_LOCK_STATE;
302
303 if (GC_have_errors) GC_print_all_errors();
304 GC_INVOKE_FINALIZERS();
305 DISABLE_SIGNALS();
306 LOCK();
307 op = GC_generic_malloc_words_small_inner(lw, k);
308 UNLOCK();
309 ENABLE_SIGNALS();
310 return((ptr_t)op);
311 }
312
313 #if defined(THREADS) && !defined(SRC_M3)
314
315 extern signed_word GC_mem_found; /* Protected by GC lock. */
316
317 #ifdef PARALLEL_MARK
318 volatile signed_word GC_words_allocd_tmp = 0;
319 /* Number of words of memory allocated since */
320 /* we released the GC lock. Instead of */
321 /* reacquiring the GC lock just to add this in, */
322 /* we add it in the next time we reacquire */
323 /* the lock. (Atomically adding it doesn't */
324 /* work, since we would have to atomically */
325 /* update it in GC_malloc, which is too */
326 /* expensive. */
327 #endif /* PARALLEL_MARK */
328
329 /* See reclaim.c: */
330 extern ptr_t GC_reclaim_generic();
331
332 /* Return a list of 1 or more objects of the indicated size, linked */
333 /* through the first word in the object. This has the advantage that */
334 /* it acquires the allocation lock only once, and may greatly reduce */
335 /* time wasted contending for the allocation lock. Typical usage would */
336 /* be in a thread that requires many items of the same size. It would */
337 /* keep its own free list in thread-local storage, and call */
338 /* GC_malloc_many or friends to replenish it. (We do not round up */
339 /* object sizes, since a call indicates the intention to consume many */
340 /* objects of exactly this size.) */
341 /* We return the free-list by assigning it to *result, since it is */
342 /* not safe to return, e.g. a linked list of pointer-free objects, */
343 /* since the collector would not retain the entire list if it were */
344 /* invoked just as we were returning. */
345 /* Note that the client should usually clear the link field. */
GC_generic_malloc_many(lb,k,result)346 void GC_generic_malloc_many(lb, k, result)
347 register word lb;
348 register int k;
349 ptr_t *result;
350 {
351 ptr_t op;
352 ptr_t p;
353 ptr_t *opp;
354 word lw;
355 word my_words_allocd = 0;
356 struct obj_kind * ok = &(GC_obj_kinds[k]);
357 DCL_LOCK_STATE;
358
359 # if defined(GATHERSTATS) || defined(PARALLEL_MARK)
360 # define COUNT_ARG , &my_words_allocd
361 # else
362 # define COUNT_ARG
363 # define NEED_TO_COUNT
364 # endif
365 if (!SMALL_OBJ(lb)) {
366 op = GC_generic_malloc(lb, k);
367 if(0 != op) obj_link(op) = 0;
368 *result = op;
369 return;
370 }
371 lw = ALIGNED_WORDS(lb);
372 if (GC_have_errors) GC_print_all_errors();
373 GC_INVOKE_FINALIZERS();
374 DISABLE_SIGNALS();
375 LOCK();
376 if (!GC_is_initialized) GC_init_inner();
377 /* Do our share of marking work */
378 if (GC_incremental && !GC_dont_gc) {
379 ENTER_GC();
380 GC_collect_a_little_inner(1);
381 EXIT_GC();
382 }
383 /* First see if we can reclaim a page of objects waiting to be */
384 /* reclaimed. */
385 {
386 struct hblk ** rlh = ok -> ok_reclaim_list;
387 struct hblk * hbp;
388 hdr * hhdr;
389
390 rlh += lw;
391 while ((hbp = *rlh) != 0) {
392 hhdr = HDR(hbp);
393 *rlh = hhdr -> hb_next;
394 hhdr -> hb_last_reclaimed = (unsigned short) GC_gc_no;
395 # ifdef PARALLEL_MARK
396 {
397 signed_word my_words_allocd_tmp = GC_words_allocd_tmp;
398
399 GC_ASSERT(my_words_allocd_tmp >= 0);
400 /* We only decrement it while holding the GC lock. */
401 /* Thus we can't accidentally adjust it down in more */
402 /* than one thread simultaneously. */
403 if (my_words_allocd_tmp != 0) {
404 (void)GC_atomic_add(
405 (volatile GC_word *)(&GC_words_allocd_tmp),
406 (GC_word)(-my_words_allocd_tmp));
407 GC_words_allocd += my_words_allocd_tmp;
408 }
409 }
410 GC_acquire_mark_lock();
411 ++ GC_fl_builder_count;
412 UNLOCK();
413 ENABLE_SIGNALS();
414 GC_release_mark_lock();
415 # endif
416 op = GC_reclaim_generic(hbp, hhdr, lw,
417 ok -> ok_init, 0 COUNT_ARG);
418 if (op != 0) {
419 # ifdef NEED_TO_COUNT
420 /* We are neither gathering statistics, nor marking in */
421 /* parallel. Thus GC_reclaim_generic doesn't count */
422 /* for us. */
423 for (p = op; p != 0; p = obj_link(p)) {
424 my_words_allocd += lw;
425 }
426 # endif
427 # if defined(GATHERSTATS)
428 /* We also reclaimed memory, so we need to adjust */
429 /* that count. */
430 /* This should be atomic, so the results may be */
431 /* inaccurate. */
432 GC_mem_found += my_words_allocd;
433 # endif
434 # ifdef PARALLEL_MARK
435 *result = op;
436 (void)GC_atomic_add(
437 (volatile GC_word *)(&GC_words_allocd_tmp),
438 (GC_word)(my_words_allocd));
439 GC_acquire_mark_lock();
440 -- GC_fl_builder_count;
441 if (GC_fl_builder_count == 0) GC_notify_all_builder();
442 GC_release_mark_lock();
443 (void) GC_clear_stack(0);
444 return;
445 # else
446 GC_words_allocd += my_words_allocd;
447 goto out;
448 # endif
449 }
450 # ifdef PARALLEL_MARK
451 GC_acquire_mark_lock();
452 -- GC_fl_builder_count;
453 if (GC_fl_builder_count == 0) GC_notify_all_builder();
454 GC_release_mark_lock();
455 DISABLE_SIGNALS();
456 LOCK();
457 /* GC lock is needed for reclaim list access. We */
458 /* must decrement fl_builder_count before reaquiring GC */
459 /* lock. Hopefully this path is rare. */
460 # endif
461 }
462 }
463 /* Next try to use prefix of global free list if there is one. */
464 /* We don't refill it, but we need to use it up before allocating */
465 /* a new block ourselves. */
466 opp = &(GC_obj_kinds[k].ok_freelist[lw]);
467 if ( (op = *opp) != 0 ) {
468 *opp = 0;
469 my_words_allocd = 0;
470 for (p = op; p != 0; p = obj_link(p)) {
471 my_words_allocd += lw;
472 if (my_words_allocd >= BODY_SZ) {
473 *opp = obj_link(p);
474 obj_link(p) = 0;
475 break;
476 }
477 }
478 GC_words_allocd += my_words_allocd;
479 goto out;
480 }
481 /* Next try to allocate a new block worth of objects of this size. */
482 {
483 struct hblk *h = GC_allochblk(lw, k, 0);
484 if (h != 0) {
485 if (IS_UNCOLLECTABLE(k)) GC_set_hdr_marks(HDR(h));
486 GC_words_allocd += BYTES_TO_WORDS(HBLKSIZE)
487 - BYTES_TO_WORDS(HBLKSIZE) % lw;
488 # ifdef PARALLEL_MARK
489 GC_acquire_mark_lock();
490 ++ GC_fl_builder_count;
491 UNLOCK();
492 ENABLE_SIGNALS();
493 GC_release_mark_lock();
494 # endif
495
496 op = GC_build_fl(h, lw, ok -> ok_init, 0);
497 # ifdef PARALLEL_MARK
498 *result = op;
499 GC_acquire_mark_lock();
500 -- GC_fl_builder_count;
501 if (GC_fl_builder_count == 0) GC_notify_all_builder();
502 GC_release_mark_lock();
503 (void) GC_clear_stack(0);
504 return;
505 # else
506 goto out;
507 # endif
508 }
509 }
510
511 /* As a last attempt, try allocating a single object. Note that */
512 /* this may trigger a collection or expand the heap. */
513 op = GC_generic_malloc_inner(lb, k);
514 if (0 != op) obj_link(op) = 0;
515
516 out:
517 *result = op;
518 UNLOCK();
519 ENABLE_SIGNALS();
520 (void) GC_clear_stack(0);
521 }
522
GC_malloc_many(size_t lb)523 GC_PTR GC_malloc_many(size_t lb)
524 {
525 ptr_t result;
526 GC_generic_malloc_many(lb, NORMAL, &result);
527 return result;
528 }
529
530 /* Note that the "atomic" version of this would be unsafe, since the */
531 /* links would not be seen by the collector. */
532 # endif
533
534 /* Allocate lb bytes of pointerful, traced, but not collectable data */
535 # ifdef __STDC__
GC_malloc_uncollectable(size_t lb)536 GC_PTR GC_malloc_uncollectable(size_t lb)
537 # else
538 GC_PTR GC_malloc_uncollectable(lb)
539 size_t lb;
540 # endif
541 {
542 register ptr_t op;
543 register ptr_t *opp;
544 register word lw;
545 DCL_LOCK_STATE;
546
547 if( SMALL_OBJ(lb) ) {
548 # ifdef MERGE_SIZES
549 if (EXTRA_BYTES != 0 && lb != 0) lb--;
550 /* We don't need the extra byte, since this won't be */
551 /* collected anyway. */
552 lw = GC_size_map[lb];
553 # else
554 lw = ALIGNED_WORDS(lb);
555 # endif
556 opp = &(GC_uobjfreelist[lw]);
557 FASTLOCK();
558 if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
559 /* See above comment on signals. */
560 *opp = obj_link(op);
561 obj_link(op) = 0;
562 GC_words_allocd += lw;
563 /* Mark bit ws already set on free list. It will be */
564 /* cleared only temporarily during a collection, as a */
565 /* result of the normal free list mark bit clearing. */
566 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
567 FASTUNLOCK();
568 return((GC_PTR) op);
569 }
570 FASTUNLOCK();
571 op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
572 } else {
573 op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
574 }
575 if (0 == op) return(0);
576 /* We don't need the lock here, since we have an undisguised */
577 /* pointer. We do need to hold the lock while we adjust */
578 /* mark bits. */
579 {
580 register struct hblk * h;
581
582 h = HBLKPTR(op);
583 lw = HDR(h) -> hb_sz;
584
585 DISABLE_SIGNALS();
586 LOCK();
587 GC_set_mark_bit(op);
588 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
589 UNLOCK();
590 ENABLE_SIGNALS();
591 return((GC_PTR) op);
592 }
593 }
594
595 #ifdef __STDC__
596 /* Not well tested nor integrated. */
597 /* Debug version is tricky and currently missing. */
598 #include <limits.h>
599
GC_memalign(size_t align,size_t lb)600 GC_PTR GC_memalign(size_t align, size_t lb)
601 {
602 size_t new_lb;
603 size_t offset;
604 ptr_t result;
605
606 # ifdef ALIGN_DOUBLE
607 if (align <= WORDS_TO_BYTES(2) && lb > align) return GC_malloc(lb);
608 # endif
609 if (align <= WORDS_TO_BYTES(1)) return GC_malloc(lb);
610 if (align >= HBLKSIZE/2 || lb >= HBLKSIZE/2) {
611 if (align > HBLKSIZE) return GC_oom_fn(LONG_MAX-1024) /* Fail */;
612 return GC_malloc(lb <= HBLKSIZE? HBLKSIZE : lb);
613 /* Will be HBLKSIZE aligned. */
614 }
615 /* We could also try to make sure that the real rounded-up object size */
616 /* is a multiple of align. That would be correct up to HBLKSIZE. */
617 new_lb = lb + align - 1;
618 result = GC_malloc(new_lb);
619 offset = (word)result % align;
620 if (offset != 0) {
621 offset = align - offset;
622 if (!GC_all_interior_pointers) {
623 if (offset >= VALID_OFFSET_SZ) return GC_malloc(HBLKSIZE);
624 GC_register_displacement(offset);
625 }
626 }
627 result = (GC_PTR) ((ptr_t)result + offset);
628 GC_ASSERT((word)result % align == 0);
629 return result;
630 }
631 #endif
632
633 # ifdef ATOMIC_UNCOLLECTABLE
634 /* Allocate lb bytes of pointerfree, untraced, uncollectable data */
635 /* This is normally roughly equivalent to the system malloc. */
636 /* But it may be useful if malloc is redefined. */
637 # ifdef __STDC__
GC_malloc_atomic_uncollectable(size_t lb)638 GC_PTR GC_malloc_atomic_uncollectable(size_t lb)
639 # else
640 GC_PTR GC_malloc_atomic_uncollectable(lb)
641 size_t lb;
642 # endif
643 {
644 register ptr_t op;
645 register ptr_t *opp;
646 register word lw;
647 DCL_LOCK_STATE;
648
649 if( SMALL_OBJ(lb) ) {
650 # ifdef MERGE_SIZES
651 if (EXTRA_BYTES != 0 && lb != 0) lb--;
652 /* We don't need the extra byte, since this won't be */
653 /* collected anyway. */
654 lw = GC_size_map[lb];
655 # else
656 lw = ALIGNED_WORDS(lb);
657 # endif
658 opp = &(GC_auobjfreelist[lw]);
659 FASTLOCK();
660 if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
661 /* See above comment on signals. */
662 *opp = obj_link(op);
663 obj_link(op) = 0;
664 GC_words_allocd += lw;
665 /* Mark bit was already set while object was on free list. */
666 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
667 FASTUNLOCK();
668 return((GC_PTR) op);
669 }
670 FASTUNLOCK();
671 op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
672 } else {
673 op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
674 }
675 if (0 == op) return(0);
676 /* We don't need the lock here, since we have an undisguised */
677 /* pointer. We do need to hold the lock while we adjust */
678 /* mark bits. */
679 {
680 register struct hblk * h;
681
682 h = HBLKPTR(op);
683 lw = HDR(h) -> hb_sz;
684
685 DISABLE_SIGNALS();
686 LOCK();
687 GC_set_mark_bit(op);
688 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
689 UNLOCK();
690 ENABLE_SIGNALS();
691 return((GC_PTR) op);
692 }
693 }
694
695 #endif /* ATOMIC_UNCOLLECTABLE */
696