Daily bump.
[official-gcc.git] / boehm-gc / alloc.c
blob45c71d3fd06dce6267b0d4a7d9c9ac08e71dd7f9
1 /*
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"
21 # include <stdio.h>
22 # if !defined(MACOS) && !defined(MSWINCE)
23 # include <signal.h>
24 # include <sys/types.h>
25 # endif
28 * Separate free lists are maintained for different sized objects
29 * up to MAXOBJSZ.
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);
38 * ptr = *opp;
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
44 * their first word.
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
55 * allocator.
58 word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */
60 word GC_gc_no = 0;
62 #ifndef SMALL_CONFIG
63 int GC_incremental = 0; /* By default, stop the world. */
64 #endif
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 */
70 /* or not. */
72 GC_bool GC_need_full_gc = FALSE;
73 /* Need full GC do to heap growth. */
75 #ifdef THREADS
76 GC_bool GC_world_stopped = FALSE;
77 # define IF_THREADS(x) x
78 #else
79 # define IF_THREADS(x)
80 #endif
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." };
93 # include "version.h"
95 /* some more variables */
97 extern signed_word GC_mem_found; /* Number of reclaimed longwords */
98 /* after garbage collection */
100 GC_bool GC_dont_expand = 0;
102 word GC_free_space_divisor = 3;
104 extern GC_bool GC_collection_in_progress();
105 /* Collection is in progress, or was abandoned. */
107 int GC_never_stop_func GC_PROTO((void)) { return(0); }
109 unsigned long GC_time_limit = TIME_LIMIT;
111 CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
112 /* used only in GC_timeout_stop_func. */
114 int GC_n_attempts = 0; /* Number of attempts at finishing */
115 /* collection within GC_time_limit. */
117 #if defined(SMALL_CONFIG) || defined(NO_CLOCK)
118 # define GC_timeout_stop_func GC_never_stop_func
119 #else
120 int GC_timeout_stop_func GC_PROTO((void))
122 CLOCK_TYPE current_time;
123 static unsigned count = 0;
124 unsigned long time_diff;
126 if ((count++ & 3) != 0) return(0);
127 GET_TIME(current_time);
128 time_diff = MS_TIME_DIFF(current_time,GC_start_time);
129 if (time_diff >= GC_time_limit) {
130 # ifdef CONDPRINT
131 if (GC_print_stats) {
132 GC_printf0("Abandoning stopped marking after ");
133 GC_printf1("%lu msecs", (unsigned long)time_diff);
134 GC_printf1("(attempt %ld)\n", (unsigned long) GC_n_attempts);
136 # endif
137 return(1);
139 return(0);
141 #endif /* !SMALL_CONFIG */
143 /* Return the minimum number of words that must be allocated between */
144 /* collections to amortize the collection cost. */
145 static word min_words_allocd()
147 # ifdef THREADS
148 /* We punt, for now. */
149 register signed_word stack_size = 10000;
150 # else
151 int dummy;
152 register signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
153 # endif
154 word total_root_size; /* includes double stack size, */
155 /* since the stack is expensive */
156 /* to scan. */
157 word scan_size; /* Estimate of memory to be scanned */
158 /* during normal GC. */
160 if (stack_size < 0) stack_size = -stack_size;
161 total_root_size = 2 * stack_size + GC_root_size;
162 scan_size = BYTES_TO_WORDS(GC_heapsize - GC_large_free_bytes
163 + (GC_large_free_bytes >> 2)
164 /* use a bit more of large empty heap */
165 + total_root_size);
166 if (TRUE_INCREMENTAL) {
167 return scan_size / (2 * GC_free_space_divisor);
168 } else {
169 return scan_size / GC_free_space_divisor;
173 /* Return the number of words allocated, adjusted for explicit storage */
174 /* management, etc.. This number is used in deciding when to trigger */
175 /* collections. */
176 word GC_adj_words_allocd()
178 register signed_word result;
179 register signed_word expl_managed =
180 BYTES_TO_WORDS((long)GC_non_gc_bytes
181 - (long)GC_non_gc_bytes_at_gc);
183 /* Don't count what was explicitly freed, or newly allocated for */
184 /* explicit management. Note that deallocating an explicitly */
185 /* managed object should not alter result, assuming the client */
186 /* is playing by the rules. */
187 result = (signed_word)GC_words_allocd
188 - (signed_word)GC_mem_freed
189 + (signed_word)GC_finalizer_mem_freed - expl_managed;
190 if (result > (signed_word)GC_words_allocd) {
191 result = GC_words_allocd;
192 /* probably client bug or unfortunate scheduling */
194 result += GC_words_finalized;
195 /* We count objects enqueued for finalization as though they */
196 /* had been reallocated this round. Finalization is user */
197 /* visible progress. And if we don't count this, we have */
198 /* stability problems for programs that finalize all objects. */
199 result += GC_words_wasted;
200 /* This doesn't reflect useful work. But if there is lots of */
201 /* new fragmentation, the same is probably true of the heap, */
202 /* and the collection will be correspondingly cheaper. */
203 if (result < (signed_word)(GC_words_allocd >> 3)) {
204 /* Always count at least 1/8 of the allocations. We don't want */
205 /* to collect too infrequently, since that would inhibit */
206 /* coalescing of free storage blocks. */
207 /* This also makes us partially robust against client bugs. */
208 return(GC_words_allocd >> 3);
209 } else {
210 return(result);
215 /* Clear up a few frames worth of garbage left at the top of the stack. */
216 /* This is used to prevent us from accidentally treating garbade left */
217 /* on the stack by other parts of the collector as roots. This */
218 /* differs from the code in misc.c, which actually tries to keep the */
219 /* stack clear of long-lived, client-generated garbage. */
220 void GC_clear_a_few_frames()
222 # define NWORDS 64
223 word frames[NWORDS];
224 register int i;
226 for (i = 0; i < NWORDS; i++) frames[i] = 0;
229 /* Heap size at which we need a collection to avoid expanding past */
230 /* limits used by blacklisting. */
231 static word GC_collect_at_heapsize = (word)(-1);
233 /* Have we allocated enough to amortize a collection? */
234 GC_bool GC_should_collect()
236 return(GC_adj_words_allocd() >= min_words_allocd()
237 || GC_heapsize >= GC_collect_at_heapsize);
241 void GC_notify_full_gc()
243 if (GC_start_call_back != (void (*) GC_PROTO((void)))0) {
244 (*GC_start_call_back)();
248 GC_bool GC_is_full_gc = FALSE;
251 * Initiate a garbage collection if appropriate.
252 * Choose judiciously
253 * between partial, full, and stop-world collections.
254 * Assumes lock held, signals disabled.
256 void GC_maybe_gc()
258 static int n_partial_gcs = 0;
260 if (GC_should_collect()) {
261 if (!GC_incremental) {
262 GC_gcollect_inner();
263 n_partial_gcs = 0;
264 return;
265 } else {
266 # ifdef PARALLEL_MARK
267 GC_wait_for_reclaim();
268 # endif
269 if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
270 # ifdef CONDPRINT
271 if (GC_print_stats) {
272 GC_printf2(
273 "***>Full mark for collection %lu after %ld allocd bytes\n",
274 (unsigned long) GC_gc_no+1,
275 (long)WORDS_TO_BYTES(GC_words_allocd));
277 # endif
278 GC_promote_black_lists();
279 (void)GC_reclaim_all((GC_stop_func)0, TRUE);
280 GC_clear_marks();
281 n_partial_gcs = 0;
282 GC_notify_full_gc();
283 GC_is_full_gc = TRUE;
284 } else {
285 n_partial_gcs++;
288 /* We try to mark with the world stopped. */
289 /* If we run out of time, this turns into */
290 /* incremental marking. */
291 # ifndef NO_CLOCK
292 if (GC_time_limit != GC_TIME_UNLIMITED) { GET_TIME(GC_start_time); }
293 # endif
294 if (GC_stopped_mark(GC_time_limit == GC_TIME_UNLIMITED?
295 GC_never_stop_func : GC_timeout_stop_func)) {
296 # ifdef SAVE_CALL_CHAIN
297 GC_save_callers(GC_last_stack);
298 # endif
299 GC_finish_collection();
300 } else {
301 if (!GC_is_full_gc) {
302 /* Count this as the first attempt */
303 GC_n_attempts++;
311 * Stop the world garbage collection. Assumes lock held, signals disabled.
312 * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
313 * Return TRUE if we successfully completed the collection.
315 GC_bool GC_try_to_collect_inner(stop_func)
316 GC_stop_func stop_func;
318 # ifdef CONDPRINT
319 CLOCK_TYPE start_time, current_time;
320 # endif
321 if (GC_dont_gc) return FALSE;
322 if (GC_incremental && GC_collection_in_progress()) {
323 # ifdef CONDPRINT
324 if (GC_print_stats) {
325 GC_printf0(
326 "GC_try_to_collect_inner: finishing collection in progress\n");
328 # endif /* CONDPRINT */
329 /* Just finish collection already in progress. */
330 while(GC_collection_in_progress()) {
331 if (stop_func()) return(FALSE);
332 GC_collect_a_little_inner(1);
335 if (stop_func == GC_never_stop_func) GC_notify_full_gc();
336 # ifdef CONDPRINT
337 if (GC_print_stats) {
338 if (GC_print_stats) GET_TIME(start_time);
339 GC_printf2(
340 "Initiating full world-stop collection %lu after %ld allocd bytes\n",
341 (unsigned long) GC_gc_no+1,
342 (long)WORDS_TO_BYTES(GC_words_allocd));
344 # endif
345 GC_promote_black_lists();
346 /* Make sure all blocks have been reclaimed, so sweep routines */
347 /* don't see cleared mark bits. */
348 /* If we're guaranteed to finish, then this is unnecessary. */
349 /* In the find_leak case, we have to finish to guarantee that */
350 /* previously unmarked objects are not reported as leaks. */
351 # ifdef PARALLEL_MARK
352 GC_wait_for_reclaim();
353 # endif
354 if ((GC_find_leak || stop_func != GC_never_stop_func)
355 && !GC_reclaim_all(stop_func, FALSE)) {
356 /* Aborted. So far everything is still consistent. */
357 return(FALSE);
359 GC_invalidate_mark_state(); /* Flush mark stack. */
360 GC_clear_marks();
361 # ifdef SAVE_CALL_CHAIN
362 GC_save_callers(GC_last_stack);
363 # endif
364 GC_is_full_gc = TRUE;
365 if (!GC_stopped_mark(stop_func)) {
366 if (!GC_incremental) {
367 /* We're partially done and have no way to complete or use */
368 /* current work. Reestablish invariants as cheaply as */
369 /* possible. */
370 GC_invalidate_mark_state();
371 GC_unpromote_black_lists();
372 } /* else we claim the world is already still consistent. We'll */
373 /* finish incrementally. */
374 return(FALSE);
376 GC_finish_collection();
377 # if defined(CONDPRINT)
378 if (GC_print_stats) {
379 GET_TIME(current_time);
380 GC_printf1("Complete collection took %lu msecs\n",
381 MS_TIME_DIFF(current_time,start_time));
383 # endif
384 return(TRUE);
390 * Perform n units of garbage collection work. A unit is intended to touch
391 * roughly GC_RATE pages. Every once in a while, we do more than that.
392 * This needa to be a fairly large number with our current incremental
393 * GC strategy, since otherwise we allocate too much during GC, and the
394 * cleanup gets expensive.
396 # define GC_RATE 10
397 # define MAX_PRIOR_ATTEMPTS 1
398 /* Maximum number of prior attempts at world stop marking */
399 /* A value of 1 means that we finish the second time, no matter */
400 /* how long it takes. Doesn't count the initial root scan */
401 /* for a full GC. */
403 int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
404 /* that we have made. */
406 void GC_collect_a_little_inner(n)
407 int n;
409 register int i;
411 if (GC_dont_gc) return;
412 if (GC_incremental && GC_collection_in_progress()) {
413 for (i = GC_deficit; i < GC_RATE*n; i++) {
414 if (GC_mark_some((ptr_t)0)) {
415 /* Need to finish a collection */
416 # ifdef SAVE_CALL_CHAIN
417 GC_save_callers(GC_last_stack);
418 # endif
419 # ifdef PARALLEL_MARK
420 GC_wait_for_reclaim();
421 # endif
422 if (GC_n_attempts < MAX_PRIOR_ATTEMPTS
423 && GC_time_limit != GC_TIME_UNLIMITED) {
424 GET_TIME(GC_start_time);
425 if (!GC_stopped_mark(GC_timeout_stop_func)) {
426 GC_n_attempts++;
427 break;
429 } else {
430 (void)GC_stopped_mark(GC_never_stop_func);
432 GC_finish_collection();
433 break;
436 if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
437 if (GC_deficit < 0) GC_deficit = 0;
438 } else {
439 GC_maybe_gc();
443 int GC_collect_a_little GC_PROTO(())
445 int result;
446 DCL_LOCK_STATE;
448 DISABLE_SIGNALS();
449 LOCK();
450 GC_collect_a_little_inner(1);
451 result = (int)GC_collection_in_progress();
452 UNLOCK();
453 ENABLE_SIGNALS();
454 if (!result && GC_debugging_started) GC_print_all_smashed();
455 return(result);
459 * Assumes lock is held, signals are disabled.
460 * We stop the world.
461 * If stop_func() ever returns TRUE, we may fail and return FALSE.
462 * Increment GC_gc_no if we succeed.
464 GC_bool GC_stopped_mark(stop_func)
465 GC_stop_func stop_func;
467 register int i;
468 int dummy;
469 # if defined(PRINTTIMES) || defined(CONDPRINT)
470 CLOCK_TYPE start_time, current_time;
471 # endif
473 # ifdef PRINTTIMES
474 GET_TIME(start_time);
475 # endif
476 # if defined(CONDPRINT) && !defined(PRINTTIMES)
477 if (GC_print_stats) GET_TIME(start_time);
478 # endif
479 # if defined(REGISTER_LIBRARIES_EARLY)
480 GC_cond_register_dynamic_libraries();
481 # endif
482 STOP_WORLD();
483 IF_THREADS(GC_world_stopped = TRUE);
484 # ifdef CONDPRINT
485 if (GC_print_stats) {
486 GC_printf1("--> Marking for collection %lu ",
487 (unsigned long) GC_gc_no + 1);
488 GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
489 (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
490 (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
492 # endif
493 # ifdef MAKE_BACK_GRAPH
494 if (GC_print_back_height) {
495 GC_build_back_graph();
497 # endif
499 /* Mark from all roots. */
500 /* Minimize junk left in my registers and on the stack */
501 GC_clear_a_few_frames();
502 GC_noop(0,0,0,0,0,0);
503 GC_initiate_gc();
504 for(i = 0;;i++) {
505 if ((*stop_func)()) {
506 # ifdef CONDPRINT
507 if (GC_print_stats) {
508 GC_printf0("Abandoned stopped marking after ");
509 GC_printf1("%lu iterations\n",
510 (unsigned long)i);
512 # endif
513 GC_deficit = i; /* Give the mutator a chance. */
514 IF_THREADS(GC_world_stopped = FALSE);
515 START_WORLD();
516 return(FALSE);
518 if (GC_mark_some((ptr_t)(&dummy))) break;
521 GC_gc_no++;
522 # ifdef PRINTSTATS
523 GC_printf2("Collection %lu reclaimed %ld bytes",
524 (unsigned long) GC_gc_no - 1,
525 (long)WORDS_TO_BYTES(GC_mem_found));
526 # else
527 # ifdef CONDPRINT
528 if (GC_print_stats) {
529 GC_printf1("Collection %lu finished", (unsigned long) GC_gc_no - 1);
531 # endif
532 # endif /* !PRINTSTATS */
533 # ifdef CONDPRINT
534 if (GC_print_stats) {
535 GC_printf1(" ---> heapsize = %lu bytes\n",
536 (unsigned long) GC_heapsize);
537 /* Printf arguments may be pushed in funny places. Clear the */
538 /* space. */
539 GC_printf0("");
541 # endif /* CONDPRINT */
543 /* Check all debugged objects for consistency */
544 if (GC_debugging_started) {
545 (*GC_check_heap)();
548 IF_THREADS(GC_world_stopped = FALSE);
549 START_WORLD();
550 # ifdef PRINTTIMES
551 GET_TIME(current_time);
552 GC_printf1("World-stopped marking took %lu msecs\n",
553 MS_TIME_DIFF(current_time,start_time));
554 # else
555 # ifdef CONDPRINT
556 if (GC_print_stats) {
557 GET_TIME(current_time);
558 GC_printf1("World-stopped marking took %lu msecs\n",
559 MS_TIME_DIFF(current_time,start_time));
561 # endif
562 # endif
563 return(TRUE);
566 /* Set all mark bits for the free list whose first entry is q */
567 #ifdef __STDC__
568 void GC_set_fl_marks(ptr_t q)
569 #else
570 void GC_set_fl_marks(q)
571 ptr_t q;
572 #endif
574 ptr_t p;
575 struct hblk * h, * last_h = 0;
576 hdr *hhdr;
577 int word_no;
579 for (p = q; p != 0; p = obj_link(p)){
580 h = HBLKPTR(p);
581 if (h != last_h) {
582 last_h = h;
583 hhdr = HDR(h);
585 word_no = (((word *)p) - ((word *)h));
586 set_mark_bit_from_hdr(hhdr, word_no);
590 /* Clear all mark bits for the free list whose first entry is q */
591 /* Decrement GC_mem_found by number of words on free list. */
592 #ifdef __STDC__
593 void GC_clear_fl_marks(ptr_t q)
594 #else
595 void GC_clear_fl_marks(q)
596 ptr_t q;
597 #endif
599 ptr_t p;
600 struct hblk * h, * last_h = 0;
601 hdr *hhdr;
602 int word_no;
604 for (p = q; p != 0; p = obj_link(p)){
605 h = HBLKPTR(p);
606 if (h != last_h) {
607 last_h = h;
608 hhdr = HDR(h);
610 word_no = (((word *)p) - ((word *)h));
611 clear_mark_bit_from_hdr(hhdr, word_no);
612 # ifdef GATHERSTATS
613 GC_mem_found -= hhdr -> hb_sz;
614 # endif
618 /* Finish up a collection. Assumes lock is held, signals are disabled, */
619 /* but the world is otherwise running. */
620 void GC_finish_collection()
622 # ifdef PRINTTIMES
623 CLOCK_TYPE start_time;
624 CLOCK_TYPE finalize_time;
625 CLOCK_TYPE done_time;
627 GET_TIME(start_time);
628 finalize_time = start_time;
629 # endif
631 # ifdef GATHERSTATS
632 GC_mem_found = 0;
633 # endif
634 # if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
635 if (getenv("GC_PRINT_ADDRESS_MAP") != 0) {
636 GC_print_address_map();
638 # endif
639 COND_DUMP;
640 if (GC_find_leak) {
641 /* Mark all objects on the free list. All objects should be */
642 /* marked when we're done. */
644 register word size; /* current object size */
645 int kind;
646 ptr_t q;
648 for (kind = 0; kind < GC_n_kinds; kind++) {
649 for (size = 1; size <= MAXOBJSZ; size++) {
650 q = GC_obj_kinds[kind].ok_freelist[size];
651 if (q != 0) GC_set_fl_marks(q);
655 GC_start_reclaim(TRUE);
656 /* The above just checks; it doesn't really reclaim anything. */
659 GC_finalize();
660 # ifdef STUBBORN_ALLOC
661 GC_clean_changing_list();
662 # endif
664 # ifdef PRINTTIMES
665 GET_TIME(finalize_time);
666 # endif
668 if (GC_print_back_height) {
669 # ifdef MAKE_BACK_GRAPH
670 GC_traverse_back_graph();
671 # else
672 # ifndef SMALL_CONFIG
673 GC_err_printf0("Back height not available: "
674 "Rebuild collector with -DMAKE_BACK_GRAPH\n");
675 # endif
676 # endif
679 /* Clear free list mark bits, in case they got accidentally marked */
680 /* (or GC_find_leak is set and they were intentionally marked). */
681 /* Also subtract memory remaining from GC_mem_found count. */
682 /* Note that composite objects on free list are cleared. */
683 /* Thus accidentally marking a free list is not a problem; only */
684 /* objects on the list itself will be marked, and that's fixed here. */
686 register word size; /* current object size */
687 register ptr_t q; /* pointer to current object */
688 int kind;
690 for (kind = 0; kind < GC_n_kinds; kind++) {
691 for (size = 1; size <= MAXOBJSZ; size++) {
692 q = GC_obj_kinds[kind].ok_freelist[size];
693 if (q != 0) GC_clear_fl_marks(q);
699 # ifdef PRINTSTATS
700 GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
701 (long)WORDS_TO_BYTES(GC_mem_found));
702 # endif
703 /* Reconstruct free lists to contain everything not marked */
704 GC_start_reclaim(FALSE);
705 if (GC_is_full_gc) {
706 GC_used_heap_size_after_full = USED_HEAP_SIZE;
707 GC_need_full_gc = FALSE;
708 } else {
709 GC_need_full_gc =
710 BYTES_TO_WORDS(USED_HEAP_SIZE - GC_used_heap_size_after_full)
711 > min_words_allocd();
714 # ifdef PRINTSTATS
715 GC_printf2(
716 "Immediately reclaimed %ld bytes in heap of size %lu bytes",
717 (long)WORDS_TO_BYTES(GC_mem_found),
718 (unsigned long)GC_heapsize);
719 # ifdef USE_MUNMAP
720 GC_printf1("(%lu unmapped)", GC_unmapped_bytes);
721 # endif
722 GC_printf2(
723 "\n%lu (atomic) + %lu (composite) collectable bytes in use\n",
724 (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
725 (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
726 # endif
728 GC_n_attempts = 0;
729 GC_is_full_gc = FALSE;
730 /* Reset or increment counters for next cycle */
731 GC_words_allocd_before_gc += GC_words_allocd;
732 GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
733 GC_words_allocd = 0;
734 GC_words_wasted = 0;
735 GC_mem_freed = 0;
736 GC_finalizer_mem_freed = 0;
738 # ifdef USE_MUNMAP
739 GC_unmap_old();
740 # endif
741 # ifdef PRINTTIMES
742 GET_TIME(done_time);
743 GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
744 MS_TIME_DIFF(finalize_time,start_time),
745 MS_TIME_DIFF(done_time,finalize_time));
746 # endif
749 /* Externally callable routine to invoke full, stop-world collection */
750 # if defined(__STDC__) || defined(__cplusplus)
751 int GC_try_to_collect(GC_stop_func stop_func)
752 # else
753 int GC_try_to_collect(stop_func)
754 GC_stop_func stop_func;
755 # endif
757 int result;
758 DCL_LOCK_STATE;
760 if (GC_debugging_started) GC_print_all_smashed();
761 GC_INVOKE_FINALIZERS();
762 DISABLE_SIGNALS();
763 LOCK();
764 ENTER_GC();
765 if (!GC_is_initialized) GC_init_inner();
766 /* Minimize junk left in my registers */
767 GC_noop(0,0,0,0,0,0);
768 result = (int)GC_try_to_collect_inner(stop_func);
769 EXIT_GC();
770 UNLOCK();
771 ENABLE_SIGNALS();
772 if(result) {
773 if (GC_debugging_started) GC_print_all_smashed();
774 GC_INVOKE_FINALIZERS();
776 return(result);
779 void GC_gcollect GC_PROTO(())
781 (void)GC_try_to_collect(GC_never_stop_func);
782 if (GC_have_errors) GC_print_all_errors();
785 word GC_n_heap_sects = 0; /* Number of sections currently in heap. */
788 * Use the chunk of memory starting at p of size bytes as part of the heap.
789 * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
791 void GC_add_to_heap(p, bytes)
792 struct hblk *p;
793 word bytes;
795 word words;
796 hdr * phdr;
798 if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
799 ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
801 phdr = GC_install_header(p);
802 if (0 == phdr) {
803 /* This is extremely unlikely. Can't add it. This will */
804 /* almost certainly result in a 0 return from the allocator, */
805 /* which is entirely appropriate. */
806 return;
808 GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
809 GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
810 GC_n_heap_sects++;
811 words = BYTES_TO_WORDS(bytes);
812 phdr -> hb_sz = words;
813 phdr -> hb_map = (unsigned char *)1; /* A value != GC_invalid_map */
814 phdr -> hb_flags = 0;
815 GC_freehblk(p);
816 GC_heapsize += bytes;
817 if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr
818 || GC_least_plausible_heap_addr == 0) {
819 GC_least_plausible_heap_addr = (GC_PTR)((ptr_t)p - sizeof(word));
820 /* Making it a little smaller than necessary prevents */
821 /* us from getting a false hit from the variable */
822 /* itself. There's some unintentional reflection */
823 /* here. */
825 if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) {
826 GC_greatest_plausible_heap_addr = (GC_PTR)((ptr_t)p + bytes);
830 # if !defined(NO_DEBUGGING)
831 void GC_print_heap_sects()
833 register unsigned i;
835 GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
836 for (i = 0; i < GC_n_heap_sects; i++) {
837 unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
838 unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
839 struct hblk *h;
840 unsigned nbl = 0;
842 GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
843 start, (unsigned long)(start + len));
844 for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
845 if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
847 GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
848 (unsigned long)(len/HBLKSIZE));
851 # endif
853 GC_PTR GC_least_plausible_heap_addr = (GC_PTR)ONES;
854 GC_PTR GC_greatest_plausible_heap_addr = 0;
856 ptr_t GC_max(x,y)
857 ptr_t x, y;
859 return(x > y? x : y);
862 ptr_t GC_min(x,y)
863 ptr_t x, y;
865 return(x < y? x : y);
868 # if defined(__STDC__) || defined(__cplusplus)
869 void GC_set_max_heap_size(GC_word n)
870 # else
871 void GC_set_max_heap_size(n)
872 GC_word n;
873 # endif
875 GC_max_heapsize = n;
878 GC_word GC_max_retries = 0;
881 * this explicitly increases the size of the heap. It is used
882 * internally, but may also be invoked from GC_expand_hp by the user.
883 * The argument is in units of HBLKSIZE.
884 * Tiny values of n are rounded up.
885 * Returns FALSE on failure.
887 GC_bool GC_expand_hp_inner(n)
888 word n;
890 word bytes;
891 struct hblk * space;
892 word expansion_slop; /* Number of bytes by which we expect the */
893 /* heap to expand soon. */
895 if (n < MINHINCR) n = MINHINCR;
896 bytes = n * HBLKSIZE;
897 /* Make sure bytes is a multiple of GC_page_size */
899 word mask = GC_page_size - 1;
900 bytes += mask;
901 bytes &= ~mask;
904 if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
905 /* Exceeded self-imposed limit */
906 return(FALSE);
908 space = GET_MEM(bytes);
909 if( space == 0 ) {
910 # ifdef CONDPRINT
911 if (GC_print_stats) {
912 GC_printf1("Failed to expand heap by %ld bytes\n",
913 (unsigned long)bytes);
915 # endif
916 return(FALSE);
918 # ifdef CONDPRINT
919 if (GC_print_stats) {
920 GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
921 (unsigned long)bytes,
922 (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
923 # ifdef UNDEFINED
924 GC_printf1("Root size = %lu\n", GC_root_size);
925 GC_print_block_list(); GC_print_hblkfreelist();
926 GC_printf0("\n");
927 # endif
929 # endif
930 expansion_slop = WORDS_TO_BYTES(min_words_allocd()) + 4*MAXHINCR*HBLKSIZE;
931 if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
932 || GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space) {
933 /* Assume the heap is growing up */
934 GC_greatest_plausible_heap_addr =
935 (GC_PTR)GC_max((ptr_t)GC_greatest_plausible_heap_addr,
936 (ptr_t)space + bytes + expansion_slop);
937 } else {
938 /* Heap is growing down */
939 GC_least_plausible_heap_addr =
940 (GC_PTR)GC_min((ptr_t)GC_least_plausible_heap_addr,
941 (ptr_t)space - expansion_slop);
943 # if defined(LARGE_CONFIG)
944 if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes
945 || (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space)
946 && GC_heapsize > 0) {
947 /* GC_add_to_heap will fix this, but ... */
948 WARN("Too close to address space limit: blacklisting ineffective\n", 0);
950 # endif
951 GC_prev_heap_addr = GC_last_heap_addr;
952 GC_last_heap_addr = (ptr_t)space;
953 GC_add_to_heap(space, bytes);
954 /* Force GC before we are likely to allocate past expansion_slop */
955 GC_collect_at_heapsize =
956 GC_heapsize + expansion_slop - 2*MAXHINCR*HBLKSIZE;
957 # if defined(LARGE_CONFIG)
958 if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
959 GC_collect_at_heapsize = (word)(-1);
960 # endif
961 return(TRUE);
964 /* Really returns a bool, but it's externally visible, so that's clumsy. */
965 /* Arguments is in bytes. */
966 # if defined(__STDC__) || defined(__cplusplus)
967 int GC_expand_hp(size_t bytes)
968 # else
969 int GC_expand_hp(bytes)
970 size_t bytes;
971 # endif
973 int result;
974 DCL_LOCK_STATE;
976 DISABLE_SIGNALS();
977 LOCK();
978 if (!GC_is_initialized) GC_init_inner();
979 result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
980 if (result) GC_requested_heapsize += bytes;
981 UNLOCK();
982 ENABLE_SIGNALS();
983 return(result);
986 unsigned GC_fail_count = 0;
987 /* How many consecutive GC/expansion failures? */
988 /* Reset by GC_allochblk. */
990 GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
991 word needed_blocks;
992 GC_bool ignore_off_page;
994 if (!GC_incremental && !GC_dont_gc &&
995 (GC_dont_expand && GC_words_allocd > 0 || GC_should_collect())) {
996 GC_gcollect_inner();
997 } else {
998 word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
999 + needed_blocks;
1001 if (blocks_to_get > MAXHINCR) {
1002 word slop;
1004 if (ignore_off_page) {
1005 slop = 4;
1006 } else {
1007 slop = 2*divHBLKSZ(BL_LIMIT);
1008 if (slop > needed_blocks) slop = needed_blocks;
1010 if (needed_blocks + slop > MAXHINCR) {
1011 blocks_to_get = needed_blocks + slop;
1012 } else {
1013 blocks_to_get = MAXHINCR;
1016 if (!GC_expand_hp_inner(blocks_to_get)
1017 && !GC_expand_hp_inner(needed_blocks)) {
1018 if (GC_fail_count++ < GC_max_retries) {
1019 WARN("Out of Memory! Trying to continue ...\n", 0);
1020 GC_gcollect_inner();
1021 } else {
1022 # if !defined(AMIGA) || !defined(GC_AMIGA_FASTALLOC)
1023 WARN("Out of Memory! Returning NIL!\n", 0);
1024 # endif
1025 return(FALSE);
1027 } else {
1028 # ifdef CONDPRINT
1029 if (GC_fail_count && GC_print_stats) {
1030 GC_printf0("Memory available again ...\n");
1032 # endif
1035 return(TRUE);
1039 * Make sure the object free list for sz is not empty.
1040 * Return a pointer to the first object on the free list.
1041 * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
1042 * Assumes we hold the allocator lock and signals are disabled.
1045 ptr_t GC_allocobj(sz, kind)
1046 word sz;
1047 int kind;
1049 ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
1050 GC_bool tried_minor = FALSE;
1052 if (sz == 0) return(0);
1054 while (*flh == 0) {
1055 ENTER_GC();
1056 /* Do our share of marking work */
1057 if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1);
1058 /* Sweep blocks for objects of this size */
1059 GC_continue_reclaim(sz, kind);
1060 EXIT_GC();
1061 if (*flh == 0) {
1062 GC_new_hblk(sz, kind);
1064 if (*flh == 0) {
1065 ENTER_GC();
1066 if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
1067 && ! tried_minor ) {
1068 GC_collect_a_little_inner(1);
1069 tried_minor = TRUE;
1070 } else {
1071 if (!GC_collect_or_expand((word)1,FALSE)) {
1072 EXIT_GC();
1073 return(0);
1076 EXIT_GC();
1079 /* Successful allocation; reset failure count. */
1080 GC_fail_count = 0;
1082 return(*flh);