2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
4 * Copyright (c) 1998 by Silicon Graphics. All rights reserved.
5 * Copyright (c) 1999 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.
19 # include "private/gc_priv.h"
22 # if !defined(MACOS) && !defined(MSWINCE)
24 # include <sys/types.h>
28 * Separate free lists are maintained for different sized objects
30 * The call GC_allocobj(i,k) ensures that the freelist for
31 * kind k objects of size i points to a non-empty
32 * free list. It returns a pointer to the first entry on the free list.
33 * In a single-threaded world, GC_allocobj may be called to allocate
34 * an object of (small) size i as follows:
36 * opp = &(GC_objfreelist[i]);
37 * if (*opp == 0) GC_allocobj(i, NORMAL);
39 * *opp = obj_link(ptr);
41 * Note that this is very fast if the free list is non-empty; it should
42 * only involve the execution of 4 or 5 simple instructions.
43 * All composite objects on freelists are cleared, except for
48 * The allocator uses GC_allochblk to allocate large chunks of objects.
49 * These chunks all start on addresses which are multiples of
50 * HBLKSZ. Each allocated chunk has an associated header,
51 * which can be located quickly based on the address of the chunk.
52 * (See headers.c for details.)
53 * This makes it possible to check quickly whether an
54 * arbitrary address corresponds to an object administered by the
58 word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */
63 int GC_incremental = 0; /* By default, stop the world. */
66 int GC_parallel = FALSE; /* By default, parallel GC is off. */
68 int GC_full_freq = 19; /* Every 20th collection is a full */
69 /* collection, whether we need it */
72 GC_bool GC_need_full_gc = FALSE;
73 /* Need full GC do to heap growth. */
76 GC_bool GC_world_stopped = FALSE;
77 # define IF_THREADS(x) x
79 # define IF_THREADS(x)
82 word GC_used_heap_size_after_full = 0;
84 char * GC_copyright[] =
85 {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
86 "Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ",
87 "Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ",
88 "Copyright (c) 1999-2001 by Hewlett-Packard Company. All rights reserved. ",
89 "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
90 " EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.",
91 "See source code for details." };
95 #if defined(SAVE_CALL_CHAIN) && \
96 !(defined(REDIRECT_MALLOC) && defined(GC_HAVE_BUILTIN_BACKTRACE))
97 # define SAVE_CALL_CHAIN_IN_GC
98 /* This is only safe if the call chain save mechanism won't end up */
99 /* calling GC_malloc. The GNU C library documentation suggests */
100 /* that backtrace doesn't use malloc, but at least the initial */
101 /* call in some versions does seem to invoke the dynamic linker, */
102 /* which uses malloc. */
105 /* some more variables */
107 extern signed_word GC_mem_found; /* Number of reclaimed longwords */
108 /* after garbage collection */
110 GC_bool GC_dont_expand = 0;
112 word GC_free_space_divisor = 3;
114 extern GC_bool GC_collection_in_progress();
115 /* Collection is in progress, or was abandoned. */
117 int GC_never_stop_func GC_PROTO((void)) { return(0); }
119 unsigned long GC_time_limit = TIME_LIMIT;
121 CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
122 /* used only in GC_timeout_stop_func. */
124 int GC_n_attempts = 0; /* Number of attempts at finishing */
125 /* collection within GC_time_limit. */
127 #if defined(SMALL_CONFIG) || defined(NO_CLOCK)
128 # define GC_timeout_stop_func GC_never_stop_func
130 int GC_timeout_stop_func GC_PROTO((void))
132 CLOCK_TYPE current_time;
133 static unsigned count = 0;
134 unsigned long time_diff;
136 if ((count++ & 3) != 0) return(0);
137 GET_TIME(current_time);
138 time_diff = MS_TIME_DIFF(current_time,GC_start_time);
139 if (time_diff >= GC_time_limit) {
141 if (GC_print_stats) {
142 GC_printf0("Abandoning stopped marking after ");
143 GC_printf1("%lu msecs", (unsigned long)time_diff);
144 GC_printf1("(attempt %ld)\n", (unsigned long) GC_n_attempts);
151 #endif /* !SMALL_CONFIG */
153 /* Return the minimum number of words that must be allocated between */
154 /* collections to amortize the collection cost. */
155 static word min_words_allocd()
158 /* We punt, for now. */
159 register signed_word stack_size = 10000;
162 register signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
164 word total_root_size; /* includes double stack size, */
165 /* since the stack is expensive */
167 word scan_size; /* Estimate of memory to be scanned */
168 /* during normal GC. */
170 if (stack_size < 0) stack_size = -stack_size;
171 total_root_size = 2 * stack_size + GC_root_size;
172 scan_size = BYTES_TO_WORDS(GC_heapsize - GC_large_free_bytes
173 + (GC_large_free_bytes >> 2)
174 /* use a bit more of large empty heap */
176 if (TRUE_INCREMENTAL) {
177 return scan_size / (2 * GC_free_space_divisor);
179 return scan_size / GC_free_space_divisor;
183 /* Return the number of words allocated, adjusted for explicit storage */
184 /* management, etc.. This number is used in deciding when to trigger */
186 word GC_adj_words_allocd()
188 register signed_word result;
189 register signed_word expl_managed =
190 BYTES_TO_WORDS((long)GC_non_gc_bytes
191 - (long)GC_non_gc_bytes_at_gc);
193 /* Don't count what was explicitly freed, or newly allocated for */
194 /* explicit management. Note that deallocating an explicitly */
195 /* managed object should not alter result, assuming the client */
196 /* is playing by the rules. */
197 result = (signed_word)GC_words_allocd
198 - (signed_word)GC_mem_freed
199 + (signed_word)GC_finalizer_mem_freed - expl_managed;
200 if (result > (signed_word)GC_words_allocd) {
201 result = GC_words_allocd;
202 /* probably client bug or unfortunate scheduling */
204 result += GC_words_finalized;
205 /* We count objects enqueued for finalization as though they */
206 /* had been reallocated this round. Finalization is user */
207 /* visible progress. And if we don't count this, we have */
208 /* stability problems for programs that finalize all objects. */
209 if ((GC_words_wasted >> 3) < result)
210 result += GC_words_wasted;
211 /* This doesn't reflect useful work. But if there is lots of */
212 /* new fragmentation, the same is probably true of the heap, */
213 /* and the collection will be correspondingly cheaper. */
214 if (result < (signed_word)(GC_words_allocd >> 3)) {
215 /* Always count at least 1/8 of the allocations. We don't want */
216 /* to collect too infrequently, since that would inhibit */
217 /* coalescing of free storage blocks. */
218 /* This also makes us partially robust against client bugs. */
219 return(GC_words_allocd >> 3);
226 /* Clear up a few frames worth of garbage left at the top of the stack. */
227 /* This is used to prevent us from accidentally treating garbade left */
228 /* on the stack by other parts of the collector as roots. This */
229 /* differs from the code in misc.c, which actually tries to keep the */
230 /* stack clear of long-lived, client-generated garbage. */
231 void GC_clear_a_few_frames()
235 /* Some compilers will warn that frames was set but never used. */
236 /* That's the whole idea ... */
239 for (i = 0; i < NWORDS; i++) frames[i] = 0;
242 /* Heap size at which we need a collection to avoid expanding past */
243 /* limits used by blacklisting. */
244 static word GC_collect_at_heapsize = (word)(-1);
246 /* Have we allocated enough to amortize a collection? */
247 GC_bool GC_should_collect()
249 return(GC_adj_words_allocd() >= min_words_allocd()
250 || GC_heapsize >= GC_collect_at_heapsize);
254 void GC_notify_full_gc()
256 if (GC_start_call_back != (void (*) GC_PROTO((void)))0) {
257 (*GC_start_call_back)();
261 GC_bool GC_is_full_gc = FALSE;
264 * Initiate a garbage collection if appropriate.
266 * between partial, full, and stop-world collections.
267 * Assumes lock held, signals disabled.
271 static int n_partial_gcs = 0;
273 if (GC_should_collect()) {
275 GC_notify_event (GC_EVENT_START);
278 if (!GC_incremental) {
283 # ifdef PARALLEL_MARK
284 GC_wait_for_reclaim();
286 if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
288 if (GC_print_stats) {
290 "***>Full mark for collection %lu after %ld allocd bytes\n",
291 (unsigned long) GC_gc_no+1,
292 (long)WORDS_TO_BYTES(GC_words_allocd));
295 GC_promote_black_lists();
296 (void)GC_reclaim_all((GC_stop_func)0, TRUE);
300 GC_is_full_gc = TRUE;
305 /* We try to mark with the world stopped. */
306 /* If we run out of time, this turns into */
307 /* incremental marking. */
309 if (GC_time_limit != GC_TIME_UNLIMITED) { GET_TIME(GC_start_time); }
311 if (GC_stopped_mark(GC_time_limit == GC_TIME_UNLIMITED?
312 GC_never_stop_func : GC_timeout_stop_func)) {
313 # ifdef SAVE_CALL_CHAIN_IN_GC
314 GC_save_callers(GC_last_stack);
316 GC_finish_collection();
318 if (!GC_is_full_gc) {
319 /* Count this as the first attempt */
326 GC_notify_event (GC_EVENT_END);
332 * Stop the world garbage collection. Assumes lock held, signals disabled.
333 * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
334 * Return TRUE if we successfully completed the collection.
336 GC_bool GC_try_to_collect_inner(stop_func)
337 GC_stop_func stop_func;
340 CLOCK_TYPE start_time, current_time;
342 if (GC_dont_gc) return FALSE;
343 if (GC_incremental && GC_collection_in_progress()) {
345 if (GC_print_stats) {
347 "GC_try_to_collect_inner: finishing collection in progress\n");
349 # endif /* CONDPRINT */
350 /* Just finish collection already in progress. */
351 while(GC_collection_in_progress()) {
352 if (stop_func()) return(FALSE);
353 GC_collect_a_little_inner(1);
356 if (stop_func == GC_never_stop_func) GC_notify_full_gc();
358 if (GC_print_stats) {
359 if (GC_print_stats) GET_TIME(start_time);
361 "Initiating full world-stop collection %lu after %ld allocd bytes\n",
362 (unsigned long) GC_gc_no+1,
363 (long)WORDS_TO_BYTES(GC_words_allocd));
366 GC_promote_black_lists();
367 /* Make sure all blocks have been reclaimed, so sweep routines */
368 /* don't see cleared mark bits. */
369 /* If we're guaranteed to finish, then this is unnecessary. */
370 /* In the find_leak case, we have to finish to guarantee that */
371 /* previously unmarked objects are not reported as leaks. */
372 # ifdef PARALLEL_MARK
373 GC_wait_for_reclaim();
375 if ((GC_find_leak || stop_func != GC_never_stop_func)
376 && !GC_reclaim_all(stop_func, FALSE)) {
377 /* Aborted. So far everything is still consistent. */
380 GC_invalidate_mark_state(); /* Flush mark stack. */
382 # ifdef SAVE_CALL_CHAIN_IN_GC
383 GC_save_callers(GC_last_stack);
385 GC_is_full_gc = TRUE;
386 if (!GC_stopped_mark(stop_func)) {
387 if (!GC_incremental) {
388 /* We're partially done and have no way to complete or use */
389 /* current work. Reestablish invariants as cheaply as */
391 GC_invalidate_mark_state();
392 GC_unpromote_black_lists();
393 } /* else we claim the world is already still consistent. We'll */
394 /* finish incrementally. */
397 GC_finish_collection();
398 # if defined(CONDPRINT)
399 if (GC_print_stats) {
400 GET_TIME(current_time);
401 GC_printf1("Complete collection took %lu msecs\n",
402 MS_TIME_DIFF(current_time,start_time));
411 * Perform n units of garbage collection work. A unit is intended to touch
412 * roughly GC_RATE pages. Every once in a while, we do more than that.
413 * This needa to be a fairly large number with our current incremental
414 * GC strategy, since otherwise we allocate too much during GC, and the
415 * cleanup gets expensive.
418 # define MAX_PRIOR_ATTEMPTS 1
419 /* Maximum number of prior attempts at world stop marking */
420 /* A value of 1 means that we finish the second time, no matter */
421 /* how long it takes. Doesn't count the initial root scan */
424 int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
425 /* that we have made. */
427 void GC_collect_a_little_inner(n)
432 if (GC_dont_gc) return;
433 if (GC_incremental && GC_collection_in_progress()) {
434 for (i = GC_deficit; i < GC_RATE*n; i++) {
435 if (GC_mark_some((ptr_t)0)) {
436 /* Need to finish a collection */
437 # ifdef SAVE_CALL_CHAIN_IN_GC
438 GC_save_callers(GC_last_stack);
440 # ifdef PARALLEL_MARK
441 GC_wait_for_reclaim();
443 if (GC_n_attempts < MAX_PRIOR_ATTEMPTS
444 && GC_time_limit != GC_TIME_UNLIMITED) {
445 GET_TIME(GC_start_time);
446 if (!GC_stopped_mark(GC_timeout_stop_func)) {
451 (void)GC_stopped_mark(GC_never_stop_func);
453 GC_finish_collection();
457 if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
458 if (GC_deficit < 0) GC_deficit = 0;
464 int GC_collect_a_little GC_PROTO(())
471 GC_collect_a_little_inner(1);
472 result = (int)GC_collection_in_progress();
475 if (!result && GC_debugging_started) GC_print_all_smashed();
480 * Assumes lock is held, signals are disabled.
482 * If stop_func() ever returns TRUE, we may fail and return FALSE.
483 * Increment GC_gc_no if we succeed.
485 GC_bool GC_stopped_mark(stop_func)
486 GC_stop_func stop_func;
490 # if defined(PRINTTIMES) || defined(CONDPRINT)
491 CLOCK_TYPE start_time, current_time;
495 GET_TIME(start_time);
497 # if defined(CONDPRINT) && !defined(PRINTTIMES)
498 if (GC_print_stats) GET_TIME(start_time);
501 # if defined(REGISTER_LIBRARIES_EARLY)
502 GC_cond_register_dynamic_libraries();
505 IF_THREADS(GC_world_stopped = TRUE);
508 GC_notify_event (GC_EVENT_MARK_START);
511 if (GC_print_stats) {
512 GC_printf1("--> Marking for collection %lu ",
513 (unsigned long) GC_gc_no + 1);
514 GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
515 (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
516 (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
519 # ifdef MAKE_BACK_GRAPH
520 if (GC_print_back_height) {
521 GC_build_back_graph();
525 /* Mark from all roots. */
526 /* Minimize junk left in my registers and on the stack */
527 GC_clear_a_few_frames();
528 GC_noop(0,0,0,0,0,0);
531 if ((*stop_func)()) {
533 if (GC_print_stats) {
534 GC_printf0("Abandoned stopped marking after ");
535 GC_printf1("%lu iterations\n",
539 GC_deficit = i; /* Give the mutator a chance. */
540 IF_THREADS(GC_world_stopped = FALSE);
544 if (GC_mark_some((ptr_t)(&dummy))) break;
549 GC_printf2("Collection %lu reclaimed %ld bytes",
550 (unsigned long) GC_gc_no - 1,
551 (long)WORDS_TO_BYTES(GC_mem_found));
554 if (GC_print_stats) {
555 GC_printf1("Collection %lu finished", (unsigned long) GC_gc_no - 1);
558 # endif /* !PRINTSTATS */
560 if (GC_print_stats) {
561 GC_printf1(" ---> heapsize = %lu bytes\n",
562 (unsigned long) GC_heapsize);
563 /* Printf arguments may be pushed in funny places. Clear the */
567 # endif /* CONDPRINT */
569 /* Check all debugged objects for consistency */
570 if (GC_debugging_started) {
576 GC_notify_event (GC_EVENT_MARK_END);
578 IF_THREADS(GC_world_stopped = FALSE);
581 GET_TIME(current_time);
582 GC_printf1("World-stopped marking took %lu msecs\n",
583 MS_TIME_DIFF(current_time,start_time));
586 if (GC_print_stats) {
587 GET_TIME(current_time);
588 GC_printf1("World-stopped marking took %lu msecs\n",
589 MS_TIME_DIFF(current_time,start_time));
596 /* Set all mark bits for the free list whose first entry is q */
598 void GC_set_fl_marks(ptr_t q)
600 void GC_set_fl_marks(q)
605 struct hblk * h, * last_h = 0;
609 for (p = q; p != 0; p = obj_link(p)){
615 word_no = (((word *)p) - ((word *)h));
616 set_mark_bit_from_hdr(hhdr, word_no);
620 /* Clear all mark bits for the free list whose first entry is q */
621 /* Decrement GC_mem_found by number of words on free list. */
623 void GC_clear_fl_marks(ptr_t q)
625 void GC_clear_fl_marks(q)
630 struct hblk * h, * last_h = 0;
634 for (p = q; p != 0; p = obj_link(p)){
640 word_no = (((word *)p) - ((word *)h));
641 clear_mark_bit_from_hdr(hhdr, word_no);
643 GC_mem_found -= hhdr -> hb_sz;
648 void (*GC_notify_event) GC_PROTO((GCEventType e));
649 void (*GC_on_heap_resize) GC_PROTO((size_t new_size));
651 /* Finish up a collection. Assumes lock is held, signals are disabled, */
652 /* but the world is otherwise running. */
653 void GC_finish_collection()
656 CLOCK_TYPE start_time;
657 CLOCK_TYPE finalize_time;
658 CLOCK_TYPE done_time;
660 GET_TIME(start_time);
661 finalize_time = start_time;
666 GC_notify_event (GC_EVENT_RECLAIM_START);
671 # if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
672 if (getenv("GC_PRINT_ADDRESS_MAP") != 0) {
673 GC_print_address_map();
679 /* Mark all objects on the free list. All objects should be */
680 /* marked when we're done. */
682 register word size; /* current object size */
686 for (kind = 0; kind < GC_n_kinds; kind++) {
687 for (size = 1; size <= MAXOBJSZ; size++) {
688 q = GC_obj_kinds[kind].ok_freelist[size];
689 if (q != 0) GC_set_fl_marks(q);
693 GC_start_reclaim(TRUE);
694 /* The above just checks; it doesn't really reclaim anything. */
698 # ifdef STUBBORN_ALLOC
699 GC_clean_changing_list();
703 GET_TIME(finalize_time);
706 if (GC_print_back_height) {
707 # ifdef MAKE_BACK_GRAPH
708 GC_traverse_back_graph();
710 # ifndef SMALL_CONFIG
711 GC_err_printf0("Back height not available: "
712 "Rebuild collector with -DMAKE_BACK_GRAPH\n");
717 /* Clear free list mark bits, in case they got accidentally marked */
718 /* (or GC_find_leak is set and they were intentionally marked). */
719 /* Also subtract memory remaining from GC_mem_found count. */
720 /* Note that composite objects on free list are cleared. */
721 /* Thus accidentally marking a free list is not a problem; only */
722 /* objects on the list itself will be marked, and that's fixed here. */
724 register word size; /* current object size */
725 register ptr_t q; /* pointer to current object */
728 for (kind = 0; kind < GC_n_kinds; kind++) {
729 for (size = 1; size <= MAXOBJSZ; size++) {
730 q = GC_obj_kinds[kind].ok_freelist[size];
731 if (q != 0) GC_clear_fl_marks(q);
738 GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
739 (long)WORDS_TO_BYTES(GC_mem_found));
741 /* Reconstruct free lists to contain everything not marked */
742 GC_start_reclaim(FALSE);
744 GC_used_heap_size_after_full = USED_HEAP_SIZE;
745 GC_need_full_gc = FALSE;
748 BYTES_TO_WORDS(USED_HEAP_SIZE - GC_used_heap_size_after_full)
749 > min_words_allocd();
754 "Immediately reclaimed %ld bytes in heap of size %lu bytes",
755 (long)WORDS_TO_BYTES(GC_mem_found),
756 (unsigned long)GC_heapsize);
758 GC_printf1("(%lu unmapped)", GC_unmapped_bytes);
761 "\n%lu (atomic) + %lu (composite) collectable bytes in use\n",
762 (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
763 (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
767 GC_is_full_gc = FALSE;
768 /* Reset or increment counters for next cycle */
769 GC_words_allocd_before_gc += GC_words_allocd;
770 GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
774 GC_finalizer_mem_freed = 0;
781 GC_notify_event (GC_EVENT_RECLAIM_END);
785 GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
786 MS_TIME_DIFF(finalize_time,start_time),
787 MS_TIME_DIFF(done_time,finalize_time));
791 /* Externally callable routine to invoke full, stop-world collection */
792 # if defined(__STDC__) || defined(__cplusplus)
793 int GC_try_to_collect(GC_stop_func stop_func)
795 int GC_try_to_collect(stop_func)
796 GC_stop_func stop_func;
802 if (GC_debugging_started) GC_print_all_smashed();
803 GC_INVOKE_FINALIZERS();
807 if (!GC_is_initialized) GC_init_inner();
808 /* Minimize junk left in my registers */
809 GC_noop(0,0,0,0,0,0);
810 result = (int)GC_try_to_collect_inner(stop_func);
815 if (GC_debugging_started) GC_print_all_smashed();
816 GC_INVOKE_FINALIZERS();
821 void GC_gcollect GC_PROTO(())
823 (void)GC_try_to_collect(GC_never_stop_func);
824 if (GC_have_errors) GC_print_all_errors();
827 word GC_n_heap_sects = 0; /* Number of sections currently in heap. */
830 * Use the chunk of memory starting at p of size bytes as part of the heap.
831 * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
833 void GC_add_to_heap(p, bytes)
840 if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
841 ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
843 phdr = GC_install_header(p);
845 /* This is extremely unlikely. Can't add it. This will */
846 /* almost certainly result in a 0 return from the allocator, */
847 /* which is entirely appropriate. */
850 GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
851 GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
853 words = BYTES_TO_WORDS(bytes);
854 phdr -> hb_sz = words;
855 phdr -> hb_map = (unsigned char *)1; /* A value != GC_invalid_map */
856 phdr -> hb_flags = 0;
858 GC_heapsize += bytes;
859 if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr
860 || GC_least_plausible_heap_addr == 0) {
861 GC_least_plausible_heap_addr = (GC_PTR)((ptr_t)p - sizeof(word));
862 /* Making it a little smaller than necessary prevents */
863 /* us from getting a false hit from the variable */
864 /* itself. There's some unintentional reflection */
867 if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) {
868 GC_greatest_plausible_heap_addr = (GC_PTR)((ptr_t)p + bytes);
872 # if !defined(NO_DEBUGGING)
873 void GC_print_heap_sects()
877 GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
878 for (i = 0; i < GC_n_heap_sects; i++) {
879 unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
880 unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
884 GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
885 start, (unsigned long)(start + len));
886 for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
887 if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
889 GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
890 (unsigned long)(len/HBLKSIZE));
895 GC_PTR GC_least_plausible_heap_addr = (GC_PTR)ONES;
896 GC_PTR GC_greatest_plausible_heap_addr = 0;
901 return(x > y? x : y);
907 return(x < y? x : y);
910 # if defined(__STDC__) || defined(__cplusplus)
911 void GC_set_max_heap_size(GC_word n)
913 void GC_set_max_heap_size(n)
920 GC_word GC_max_retries = 0;
923 * this explicitly increases the size of the heap. It is used
924 * internally, but may also be invoked from GC_expand_hp by the user.
925 * The argument is in units of HBLKSIZE.
926 * Tiny values of n are rounded up.
927 * Returns FALSE on failure.
929 GC_bool GC_expand_hp_inner(n)
934 word expansion_slop; /* Number of bytes by which we expect the */
935 /* heap to expand soon. */
937 if (n < MINHINCR) n = MINHINCR;
938 bytes = n * HBLKSIZE;
939 /* Make sure bytes is a multiple of GC_page_size */
941 word mask = GC_page_size - 1;
946 if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
947 /* Exceeded self-imposed limit */
950 space = GET_MEM(bytes);
953 if (GC_print_stats) {
954 GC_printf1("Failed to expand heap by %ld bytes\n",
955 (unsigned long)bytes);
961 if (GC_print_stats) {
962 GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
963 (unsigned long)bytes,
964 (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
966 GC_printf1("Root size = %lu\n", GC_root_size);
967 GC_print_block_list(); GC_print_hblkfreelist();
972 expansion_slop = WORDS_TO_BYTES(min_words_allocd()) + 4*MAXHINCR*HBLKSIZE;
973 if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
974 || (GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space)) {
975 /* Assume the heap is growing up */
976 GC_greatest_plausible_heap_addr =
977 (GC_PTR)GC_max((ptr_t)GC_greatest_plausible_heap_addr,
978 (ptr_t)space + bytes + expansion_slop);
980 /* Heap is growing down */
981 GC_least_plausible_heap_addr =
982 (GC_PTR)GC_min((ptr_t)GC_least_plausible_heap_addr,
983 (ptr_t)space - expansion_slop);
985 # if defined(LARGE_CONFIG)
986 if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes
987 || (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space)
988 && GC_heapsize > 0) {
989 /* GC_add_to_heap will fix this, but ... */
990 WARN("Too close to address space limit: blacklisting ineffective\n", 0);
993 GC_prev_heap_addr = GC_last_heap_addr;
994 GC_last_heap_addr = (ptr_t)space;
995 GC_add_to_heap(space, bytes);
996 /* Force GC before we are likely to allocate past expansion_slop */
997 GC_collect_at_heapsize =
998 GC_heapsize + expansion_slop - 2*MAXHINCR*HBLKSIZE;
999 # if defined(LARGE_CONFIG)
1000 if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
1001 GC_collect_at_heapsize = (word)(-1);
1003 if (GC_on_heap_resize)
1004 GC_on_heap_resize (GC_heapsize);
1009 /* Really returns a bool, but it's externally visible, so that's clumsy. */
1010 /* Arguments is in bytes. */
1011 # if defined(__STDC__) || defined(__cplusplus)
1012 int GC_expand_hp(size_t bytes)
1014 int GC_expand_hp(bytes)
1023 if (!GC_is_initialized) GC_init_inner();
1024 result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
1025 if (result) GC_requested_heapsize += bytes;
1031 unsigned GC_fail_count = 0;
1032 /* How many consecutive GC/expansion failures? */
1033 /* Reset by GC_allochblk. */
1035 static word last_fo_entries = 0;
1036 static word last_words_finalized = 0;
1038 GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
1040 GC_bool ignore_off_page;
1042 if (!GC_incremental && !GC_dont_gc &&
1043 ((GC_dont_expand && GC_words_allocd > 0)
1044 || (GC_fo_entries > (last_fo_entries + 500) && (last_words_finalized || GC_words_finalized))
1045 || GC_should_collect())) {
1046 GC_gcollect_inner();
1047 last_fo_entries = GC_fo_entries;
1048 last_words_finalized = GC_words_finalized;
1050 word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
1053 if (blocks_to_get > MAXHINCR) {
1056 /* Get the minimum required to make it likely that we */
1057 /* can satisfy the current request in the presence of black- */
1058 /* listing. This will probably be more than MAXHINCR. */
1059 if (ignore_off_page) {
1062 slop = 2*divHBLKSZ(BL_LIMIT);
1063 if (slop > needed_blocks) slop = needed_blocks;
1065 if (needed_blocks + slop > MAXHINCR) {
1066 blocks_to_get = needed_blocks + slop;
1068 blocks_to_get = MAXHINCR;
1071 if (!GC_expand_hp_inner(blocks_to_get)
1072 && !GC_expand_hp_inner(needed_blocks)) {
1073 if (GC_fail_count++ < GC_max_retries) {
1074 WARN("Out of Memory! Trying to continue ...\n", 0);
1075 GC_gcollect_inner();
1077 # if !defined(AMIGA) || !defined(GC_AMIGA_FASTALLOC)
1078 WARN("Out of Memory! Returning NIL!\n", 0);
1084 if (GC_fail_count && GC_print_stats) {
1085 GC_printf0("Memory available again ...\n");
1094 * Make sure the object free list for sz is not empty.
1095 * Return a pointer to the first object on the free list.
1096 * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
1097 * Assumes we hold the allocator lock and signals are disabled.
1100 ptr_t GC_allocobj(sz, kind)
1104 ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
1105 GC_bool tried_minor = FALSE;
1107 if (sz == 0) return(0);
1111 /* Do our share of marking work */
1112 if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1);
1113 /* Sweep blocks for objects of this size */
1114 GC_continue_reclaim(sz, kind);
1117 GC_new_hblk(sz, kind);
1121 if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
1122 && ! tried_minor ) {
1123 GC_collect_a_little_inner(1);
1126 if (!GC_collect_or_expand((word)1,FALSE)) {
1134 /* Successful allocation; reset failure count. */