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.
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
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.
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.
25 #include "private/gc_priv.h"
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 */
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;
42 GC_PTR GC_generic_or_special_malloc(lb,knd)
47 # ifdef STUBBORN_ALLOC
49 return(GC_malloc_stubborn((size_t)lb));
52 return(GC_malloc_atomic((size_t)lb));
54 return(GC_malloc((size_t)lb));
56 return(GC_malloc_uncollectable((size_t)lb));
57 # ifdef ATOMIC_UNCOLLECTABLE
59 return(GC_malloc_atomic_uncollectable((size_t)lb));
60 # endif /* ATOMIC_UNCOLLECTABLE */
62 return(GC_generic_malloc(lb,knd));
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. */
72 GC_PTR GC_realloc(GC_PTR p, size_t lb)
74 GC_PTR GC_realloc(p,lb)
79 register struct hblk * h;
81 register word sz; /* Current size in bytes */
82 register word orig_sz; /* Original sz in bytes */
85 if (p == 0) return(GC_malloc(lb)); /* Required by ANSI */
89 obj_kind = hhdr -> hb_obj_kind;
90 sz = WORDS_TO_BYTES(sz);
93 if (sz > MAXOBJBYTES) {
94 /* Round it up to the next whole heap block */
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. */
105 if (ADD_SLOP(lb) <= sz) {
106 if (lb >= (sz >> 1)) {
107 # ifdef STUBBORN_ALLOC
108 if (obj_kind == STUBBORN) GC_change_stubborn(p);
111 /* Clear unneeded part of object to avoid bogus pointer */
113 /* Safe for stubborn objects. */
114 BZERO(((ptr_t)p) + lb, orig_sz - lb);
120 GC_generic_or_special_malloc((word)lb, obj_kind);
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);
134 GC_generic_or_special_malloc((word)lb, obj_kind);
136 if (result == 0) return(0);
137 BCOPY(p, result, sz);
145 # if defined(REDIRECT_MALLOC) && !defined(REDIRECT_REALLOC)
146 # define REDIRECT_REALLOC GC_realloc
149 # ifdef REDIRECT_REALLOC
151 GC_PTR realloc(GC_PTR p, size_t lb)
158 return(REDIRECT_REALLOC(p, lb));
160 # endif /* REDIRECT_REALLOC */
163 /* The same thing, except caller does not hold allocation lock. */
164 /* We avoid holding allocation lock while we clear memory. */
165 ptr_t GC_generic_malloc_ignore_off_page(lb, k)
169 register ptr_t result;
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 if (GC_have_errors) GC_print_all_errors();
181 GC_INVOKE_FINALIZERS();
184 result = (ptr_t)GC_alloc_large(lw, k, IGNORE_OFF_PAGE);
186 if (GC_debugging_started) {
187 BZERO(result, n_blocks * HBLKSIZE);
190 /* Clear any memory that might be used for GC descriptors */
191 /* before we release the lock. */
192 ((word *)result)[0] = 0;
193 ((word *)result)[1] = 0;
194 ((word *)result)[lw-1] = 0;
195 ((word *)result)[lw-2] = 0;
199 GC_words_allocd += lw;
203 return((*GC_oom_fn)(lb));
205 if (init & !GC_debugging_started) {
206 BZERO(result, n_blocks * HBLKSIZE);
212 # if defined(__STDC__) || defined(__cplusplus)
213 void * GC_malloc_ignore_off_page(size_t lb)
215 char * GC_malloc_ignore_off_page(lb)
219 return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, NORMAL));
222 # if defined(__STDC__) || defined(__cplusplus)
223 void * GC_malloc_atomic_ignore_off_page(size_t lb)
225 char * GC_malloc_atomic_ignore_off_page(lb)
229 return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, PTRFREE));
232 /* Increment GC_words_allocd from code that doesn't have direct access */
235 void GC_incr_words_allocd(size_t n)
237 GC_words_allocd += n;
240 /* The same for GC_mem_freed. */
241 void GC_incr_mem_freed(size_t n)
245 # endif /* __STDC__ */
247 /* Analogous to the above, but assumes a small object size, and */
248 /* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
249 ptr_t GC_generic_malloc_words_small_inner(lw, k)
255 register struct obj_kind * kind = GC_obj_kinds + k;
257 opp = &(kind -> ok_freelist[lw]);
258 if( (op = *opp) == 0 ) {
259 if (!GC_is_initialized) {
262 if (kind -> ok_reclaim_list != 0 || GC_alloc_reclaim_list(kind)) {
263 op = GC_clear_stack(GC_allocobj((word)lw, k));
268 return ((*GC_oom_fn)(WORDS_TO_BYTES(lw)));
273 GC_words_allocd += lw;
277 /* Analogous to the above, but assumes a small object size, and */
278 /* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
280 ptr_t GC_generic_malloc_words_small(size_t lw, int k)
282 ptr_t GC_generic_malloc_words_small(lw, k)
290 if (GC_have_errors) GC_print_all_errors();
291 GC_INVOKE_FINALIZERS();
294 op = GC_generic_malloc_words_small_inner(lw, k);
300 #if defined(THREADS) && !defined(SRC_M3)
302 extern signed_word GC_mem_found; /* Protected by GC lock. */
305 volatile signed_word GC_words_allocd_tmp = 0;
306 /* Number of words of memory allocated since */
307 /* we released the GC lock. Instead of */
308 /* reacquiring the GC lock just to add this in, */
309 /* we add it in the next time we reacquire */
310 /* the lock. (Atomically adding it doesn't */
311 /* work, since we would have to atomically */
312 /* update it in GC_malloc, which is too */
314 #endif /* PARALLEL_MARK */
317 extern ptr_t GC_reclaim_generic();
319 /* Return a list of 1 or more objects of the indicated size, linked */
320 /* through the first word in the object. This has the advantage that */
321 /* it acquires the allocation lock only once, and may greatly reduce */
322 /* time wasted contending for the allocation lock. Typical usage would */
323 /* be in a thread that requires many items of the same size. It would */
324 /* keep its own free list in thread-local storage, and call */
325 /* GC_malloc_many or friends to replenish it. (We do not round up */
326 /* object sizes, since a call indicates the intention to consume many */
327 /* objects of exactly this size.) */
328 /* We return the free-list by assigning it to *result, since it is */
329 /* not safe to return, e.g. a linked list of pointer-free objects, */
330 /* since the collector would not retain the entire list if it were */
331 /* invoked just as we were returning. */
332 /* Note that the client should usually clear the link field. */
333 void GC_generic_malloc_many(lb, k, result)
342 word my_words_allocd = 0;
343 struct obj_kind * ok = &(GC_obj_kinds[k]);
346 # if defined(GATHERSTATS) || defined(PARALLEL_MARK)
347 # define COUNT_ARG , &my_words_allocd
350 # define NEED_TO_COUNT
352 if (!SMALL_OBJ(lb)) {
353 op = GC_generic_malloc(lb, k);
354 if(0 != op) obj_link(op) = 0;
358 lw = ALIGNED_WORDS(lb);
359 if (GC_have_errors) GC_print_all_errors();
360 GC_INVOKE_FINALIZERS();
363 if (!GC_is_initialized) GC_init_inner();
364 /* Do our share of marking work */
365 if (GC_incremental && !GC_dont_gc) {
367 GC_collect_a_little_inner(1);
370 /* First see if we can reclaim a page of objects waiting to be */
373 struct hblk ** rlh = ok -> ok_reclaim_list;
378 while ((hbp = *rlh) != 0) {
380 *rlh = hhdr -> hb_next;
381 hhdr -> hb_last_reclaimed = (unsigned short) GC_gc_no;
382 # ifdef PARALLEL_MARK
384 signed_word my_words_allocd_tmp = GC_words_allocd_tmp;
386 GC_ASSERT(my_words_allocd_tmp >= 0);
387 /* We only decrement it while holding the GC lock. */
388 /* Thus we can't accidentally adjust it down in more */
389 /* than one thread simultaneously. */
390 if (my_words_allocd_tmp != 0) {
392 (volatile GC_word *)(&GC_words_allocd_tmp),
393 (GC_word)(-my_words_allocd_tmp));
394 GC_words_allocd += my_words_allocd_tmp;
397 GC_acquire_mark_lock();
398 ++ GC_fl_builder_count;
401 GC_release_mark_lock();
403 op = GC_reclaim_generic(hbp, hhdr, lw,
404 ok -> ok_init, 0 COUNT_ARG);
406 # ifdef NEED_TO_COUNT
407 /* We are neither gathering statistics, nor marking in */
408 /* parallel. Thus GC_reclaim_generic doesn't count */
410 for (p = op; p != 0; p = obj_link(p)) {
411 my_words_allocd += lw;
414 # if defined(GATHERSTATS)
415 /* We also reclaimed memory, so we need to adjust */
417 /* This should be atomic, so the results may be */
419 GC_mem_found += my_words_allocd;
421 # ifdef PARALLEL_MARK
424 (volatile GC_word *)(&GC_words_allocd_tmp),
425 (GC_word)(my_words_allocd));
426 GC_acquire_mark_lock();
427 -- GC_fl_builder_count;
428 if (GC_fl_builder_count == 0) GC_notify_all_builder();
429 GC_release_mark_lock();
430 (void) GC_clear_stack(0);
433 GC_words_allocd += my_words_allocd;
437 # ifdef PARALLEL_MARK
438 GC_acquire_mark_lock();
439 -- GC_fl_builder_count;
440 if (GC_fl_builder_count == 0) GC_notify_all_builder();
441 GC_release_mark_lock();
444 /* GC lock is needed for reclaim list access. We */
445 /* must decrement fl_builder_count before reaquiring GC */
446 /* lock. Hopefully this path is rare. */
450 /* Next try to use prefix of global free list if there is one. */
451 /* We don't refill it, but we need to use it up before allocating */
452 /* a new block ourselves. */
453 opp = &(GC_obj_kinds[k].ok_freelist[lw]);
454 if ( (op = *opp) != 0 ) {
457 for (p = op; p != 0; p = obj_link(p)) {
458 my_words_allocd += lw;
459 if (my_words_allocd >= BODY_SZ) {
465 GC_words_allocd += my_words_allocd;
468 /* Next try to allocate a new block worth of objects of this size. */
470 struct hblk *h = GC_allochblk(lw, k, 0);
472 if (IS_UNCOLLECTABLE(k)) GC_set_hdr_marks(HDR(h));
473 GC_words_allocd += BYTES_TO_WORDS(HBLKSIZE)
474 - BYTES_TO_WORDS(HBLKSIZE) % lw;
475 # ifdef PARALLEL_MARK
476 GC_acquire_mark_lock();
477 ++ GC_fl_builder_count;
480 GC_release_mark_lock();
483 op = GC_build_fl(h, lw, ok -> ok_init, 0);
484 # ifdef PARALLEL_MARK
486 GC_acquire_mark_lock();
487 -- GC_fl_builder_count;
488 if (GC_fl_builder_count == 0) GC_notify_all_builder();
489 GC_release_mark_lock();
490 (void) GC_clear_stack(0);
498 /* As a last attempt, try allocating a single object. Note that */
499 /* this may trigger a collection or expand the heap. */
500 op = GC_generic_malloc_inner(lb, k);
501 if (0 != op) obj_link(op) = 0;
507 (void) GC_clear_stack(0);
510 GC_PTR GC_malloc_many(size_t lb)
513 GC_generic_malloc_many(lb, NORMAL, &result);
517 /* Note that the "atomic" version of this would be unsafe, since the */
518 /* links would not be seen by the collector. */
521 /* Allocate lb bytes of pointerful, traced, but not collectable data */
523 GC_PTR GC_malloc_uncollectable(size_t lb)
525 GC_PTR GC_malloc_uncollectable(lb)
534 if( SMALL_OBJ(lb) ) {
536 if (EXTRA_BYTES != 0 && lb != 0) lb--;
537 /* We don't need the extra byte, since this won't be */
538 /* collected anyway. */
539 lw = GC_size_map[lb];
541 lw = ALIGNED_WORDS(lb);
543 opp = &(GC_uobjfreelist[lw]);
545 if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
546 /* See above comment on signals. */
549 GC_words_allocd += lw;
550 /* Mark bit ws already set on free list. It will be */
551 /* cleared only temporarily during a collection, as a */
552 /* result of the normal free list mark bit clearing. */
553 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
558 op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
560 op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
562 if (0 == op) return(0);
563 /* We don't need the lock here, since we have an undisguised */
564 /* pointer. We do need to hold the lock while we adjust */
567 register struct hblk * h;
570 lw = HDR(h) -> hb_sz;
575 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
583 /* Not well tested nor integrated. */
584 /* Debug version is tricky and currently missing. */
587 GC_PTR GC_memalign(size_t align, size_t lb)
594 if (align <= WORDS_TO_BYTES(2) && lb > align) return GC_malloc(lb);
596 if (align <= WORDS_TO_BYTES(1)) return GC_malloc(lb);
597 if (align >= HBLKSIZE/2 || lb >= HBLKSIZE/2) {
598 if (align > HBLKSIZE) return GC_oom_fn(LONG_MAX-1024) /* Fail */;
599 return GC_malloc(lb <= HBLKSIZE? HBLKSIZE : lb);
600 /* Will be HBLKSIZE aligned. */
602 /* We could also try to make sure that the real rounded-up object size */
603 /* is a multiple of align. That would be correct up to HBLKSIZE. */
604 new_lb = lb + align - 1;
605 result = GC_malloc(new_lb);
606 offset = (word)result % align;
608 offset = align - offset;
609 if (!GC_all_interior_pointers) {
610 if (offset >= VALID_OFFSET_SZ) return GC_malloc(HBLKSIZE);
611 GC_register_displacement(offset);
614 result = (GC_PTR) ((ptr_t)result + offset);
615 GC_ASSERT((word)result % align == 0);
620 # ifdef ATOMIC_UNCOLLECTABLE
621 /* Allocate lb bytes of pointerfree, untraced, uncollectable data */
622 /* This is normally roughly equivalent to the system malloc. */
623 /* But it may be useful if malloc is redefined. */
625 GC_PTR GC_malloc_atomic_uncollectable(size_t lb)
627 GC_PTR GC_malloc_atomic_uncollectable(lb)
636 if( SMALL_OBJ(lb) ) {
638 if (EXTRA_BYTES != 0 && lb != 0) lb--;
639 /* We don't need the extra byte, since this won't be */
640 /* collected anyway. */
641 lw = GC_size_map[lb];
643 lw = ALIGNED_WORDS(lb);
645 opp = &(GC_auobjfreelist[lw]);
647 if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
648 /* See above comment on signals. */
651 GC_words_allocd += lw;
652 /* Mark bit was already set while object was on free list. */
653 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
658 op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
660 op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
662 if (0 == op) return(0);
663 /* We don't need the lock here, since we have an undisguised */
664 /* pointer. We do need to hold the lock while we adjust */
667 register struct hblk * h;
670 lw = HDR(h) -> hb_sz;
675 GC_non_gc_bytes += WORDS_TO_BYTES(lw);
682 #endif /* ATOMIC_UNCOLLECTABLE */