Annotation of OpenXM_contrib/gc/alloc.c, Revision 1.1.1.1
1.1 maekawa 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) 1998 by Silicon Graphics. All rights reserved.
5: *
6: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
7: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
8: *
9: * Permission is hereby granted to use or copy this program
10: * for any purpose, provided the above notices are retained on all copies.
11: * Permission to modify the code and to distribute modified code is granted,
12: * provided the above notices are retained, and a notice that the code was
13: * modified is included with the above copyright notice.
14: *
15: */
16:
17:
18: # include "gc_priv.h"
19:
20: # include <stdio.h>
21: # ifndef MACOS
22: # include <signal.h>
23: # include <sys/types.h>
24: # endif
25:
26: /*
27: * Separate free lists are maintained for different sized objects
28: * up to MAXOBJSZ.
29: * The call GC_allocobj(i,k) ensures that the freelist for
30: * kind k objects of size i points to a non-empty
31: * free list. It returns a pointer to the first entry on the free list.
32: * In a single-threaded world, GC_allocobj may be called to allocate
33: * an object of (small) size i as follows:
34: *
35: * opp = &(GC_objfreelist[i]);
36: * if (*opp == 0) GC_allocobj(i, NORMAL);
37: * ptr = *opp;
38: * *opp = obj_link(ptr);
39: *
40: * Note that this is very fast if the free list is non-empty; it should
41: * only involve the execution of 4 or 5 simple instructions.
42: * All composite objects on freelists are cleared, except for
43: * their first word.
44: */
45:
46: /*
47: * The allocator uses GC_allochblk to allocate large chunks of objects.
48: * These chunks all start on addresses which are multiples of
49: * HBLKSZ. Each allocated chunk has an associated header,
50: * which can be located quickly based on the address of the chunk.
51: * (See headers.c for details.)
52: * This makes it possible to check quickly whether an
53: * arbitrary address corresponds to an object administered by the
54: * allocator.
55: */
56:
57: word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */
58:
59: word GC_gc_no = 0;
60:
61: #ifndef SMALL_CONFIG
62: int GC_incremental = 0; /* By default, stop the world. */
63: #endif
64:
65: int GC_full_freq = 4; /* Every 5th collection is a full */
66: /* collection. */
67:
68: char * GC_copyright[] =
69: {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
70: "Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ",
71: "Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ",
72: "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
73: " EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.",
74: "See source code for details." };
75:
76: # include "version.h"
77:
78: /* some more variables */
79:
80: extern signed_word GC_mem_found; /* Number of reclaimed longwords */
81: /* after garbage collection */
82:
83: GC_bool GC_dont_expand = 0;
84:
85: word GC_free_space_divisor = 4;
86:
87: extern GC_bool GC_collection_in_progress();
88: /* Collection is in progress, or was abandoned. */
89:
90: int GC_never_stop_func GC_PROTO((void)) { return(0); }
91:
92: CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
93: /* used only in GC_timeout_stop_func. */
94:
95: int GC_n_attempts = 0; /* Number of attempts at finishing */
96: /* collection within TIME_LIMIT */
97:
98: #ifdef SMALL_CONFIG
99: # define GC_timeout_stop_func GC_never_stop_func
100: #else
101: int GC_timeout_stop_func GC_PROTO((void))
102: {
103: CLOCK_TYPE current_time;
104: static unsigned count = 0;
105: unsigned long time_diff;
106:
107: if ((count++ & 3) != 0) return(0);
108: GET_TIME(current_time);
109: time_diff = MS_TIME_DIFF(current_time,GC_start_time);
110: if (time_diff >= TIME_LIMIT) {
111: # ifdef PRINTSTATS
112: GC_printf0("Abandoning stopped marking after ");
113: GC_printf1("%lu msecs", (unsigned long)time_diff);
114: GC_printf1("(attempt %d)\n", (unsigned long) GC_n_attempts);
115: # endif
116: return(1);
117: }
118: return(0);
119: }
120: #endif /* !SMALL_CONFIG */
121:
122: /* Return the minimum number of words that must be allocated between */
123: /* collections to amortize the collection cost. */
124: static word min_words_allocd()
125: {
126: # ifdef THREADS
127: /* We punt, for now. */
128: register signed_word stack_size = 10000;
129: # else
130: int dummy;
131: register signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
132: # endif
133: register word total_root_size; /* includes double stack size, */
134: /* since the stack is expensive */
135: /* to scan. */
136:
137: if (stack_size < 0) stack_size = -stack_size;
138: total_root_size = 2 * stack_size + GC_root_size;
139: if (GC_incremental) {
140: return(BYTES_TO_WORDS(GC_heapsize + total_root_size)
141: / (2 * GC_free_space_divisor));
142: } else {
143: return(BYTES_TO_WORDS(GC_heapsize + total_root_size)
144: / GC_free_space_divisor);
145: }
146: }
147:
148: /* Return the number of words allocated, adjusted for explicit storage */
149: /* management, etc.. This number is used in deciding when to trigger */
150: /* collections. */
151: word GC_adj_words_allocd()
152: {
153: register signed_word result;
154: register signed_word expl_managed =
155: BYTES_TO_WORDS((long)GC_non_gc_bytes
156: - (long)GC_non_gc_bytes_at_gc);
157:
158: /* Don't count what was explicitly freed, or newly allocated for */
159: /* explicit management. Note that deallocating an explicitly */
160: /* managed object should not alter result, assuming the client */
161: /* is playing by the rules. */
162: result = (signed_word)GC_words_allocd
163: - (signed_word)GC_mem_freed - expl_managed;
164: if (result > (signed_word)GC_words_allocd) {
165: result = GC_words_allocd;
166: /* probably client bug or unfortunate scheduling */
167: }
168: result += GC_words_finalized;
169: /* We count objects enqueued for finalization as though they */
170: /* had been reallocated this round. Finalization is user */
171: /* visible progress. And if we don't count this, we have */
172: /* stability problems for programs that finalize all objects. */
173: result += GC_words_wasted;
174: /* This doesn't reflect useful work. But if there is lots of */
175: /* new fragmentation, the same is probably true of the heap, */
176: /* and the collection will be correspondingly cheaper. */
177: if (result < (signed_word)(GC_words_allocd >> 3)) {
178: /* Always count at least 1/8 of the allocations. We don't want */
179: /* to collect too infrequently, since that would inhibit */
180: /* coalescing of free storage blocks. */
181: /* This also makes us partially robust against client bugs. */
182: return(GC_words_allocd >> 3);
183: } else {
184: return(result);
185: }
186: }
187:
188:
189: /* Clear up a few frames worth of garbage left at the top of the stack. */
190: /* This is used to prevent us from accidentally treating garbade left */
191: /* on the stack by other parts of the collector as roots. This */
192: /* differs from the code in misc.c, which actually tries to keep the */
193: /* stack clear of long-lived, client-generated garbage. */
194: void GC_clear_a_few_frames()
195: {
196: # define NWORDS 64
197: word frames[NWORDS];
198: register int i;
199:
200: for (i = 0; i < NWORDS; i++) frames[i] = 0;
201: }
202:
203: /* Have we allocated enough to amortize a collection? */
204: GC_bool GC_should_collect()
205: {
206: return(GC_adj_words_allocd() >= min_words_allocd());
207: }
208:
209: void GC_notify_full_gc()
210: {
211: if (GC_start_call_back != (void (*)())0) {
212: (*GC_start_call_back)();
213: }
214: }
215:
216: /*
217: * Initiate a garbage collection if appropriate.
218: * Choose judiciously
219: * between partial, full, and stop-world collections.
220: * Assumes lock held, signals disabled.
221: */
222: void GC_maybe_gc()
223: {
224: static int n_partial_gcs = 0;
225: GC_bool is_full_gc = FALSE;
226:
227: if (GC_should_collect()) {
228: if (!GC_incremental) {
229: GC_notify_full_gc();
230: GC_gcollect_inner();
231: n_partial_gcs = 0;
232: return;
233: } else if (n_partial_gcs >= GC_full_freq) {
234: # ifdef PRINTSTATS
235: GC_printf2(
236: "***>Full mark for collection %lu after %ld allocd bytes\n",
237: (unsigned long) GC_gc_no+1,
238: (long)WORDS_TO_BYTES(GC_words_allocd));
239: # endif
240: GC_promote_black_lists();
241: (void)GC_reclaim_all((GC_stop_func)0, TRUE);
242: GC_clear_marks();
243: n_partial_gcs = 0;
244: GC_notify_full_gc();
245: is_full_gc = TRUE;
246: } else {
247: n_partial_gcs++;
248: }
249: /* We try to mark with the world stopped. */
250: /* If we run out of time, this turns into */
251: /* incremental marking. */
252: GET_TIME(GC_start_time);
253: if (GC_stopped_mark(GC_timeout_stop_func)) {
254: # ifdef SAVE_CALL_CHAIN
255: GC_save_callers(GC_last_stack);
256: # endif
257: GC_finish_collection();
258: } else {
259: if (!is_full_gc) {
260: /* Count this as the first attempt */
261: GC_n_attempts++;
262: }
263: }
264: }
265: }
266:
267:
268: /*
269: * Stop the world garbage collection. Assumes lock held, signals disabled.
270: * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
271: */
272: GC_bool GC_try_to_collect_inner(stop_func)
273: GC_stop_func stop_func;
274: {
275: if (GC_incremental && GC_collection_in_progress()) {
276: # ifdef PRINTSTATS
277: GC_printf0(
278: "GC_try_to_collect_inner: finishing collection in progress\n");
279: # endif /* PRINTSTATS */
280: /* Just finish collection already in progress. */
281: while(GC_collection_in_progress()) {
282: if (stop_func()) return(FALSE);
283: GC_collect_a_little_inner(1);
284: }
285: }
286: # ifdef PRINTSTATS
287: GC_printf2(
288: "Initiating full world-stop collection %lu after %ld allocd bytes\n",
289: (unsigned long) GC_gc_no+1,
290: (long)WORDS_TO_BYTES(GC_words_allocd));
291: # endif
292: GC_promote_black_lists();
293: /* Make sure all blocks have been reclaimed, so sweep routines */
294: /* don't see cleared mark bits. */
295: /* If we're guaranteed to finish, then this is unnecessary. */
296: if (stop_func != GC_never_stop_func
297: && !GC_reclaim_all(stop_func, FALSE)) {
298: /* Aborted. So far everything is still consistent. */
299: return(FALSE);
300: }
301: GC_invalidate_mark_state(); /* Flush mark stack. */
302: GC_clear_marks();
303: # ifdef SAVE_CALL_CHAIN
304: GC_save_callers(GC_last_stack);
305: # endif
306: if (!GC_stopped_mark(stop_func)) {
307: if (!GC_incremental) {
308: /* We're partially done and have no way to complete or use */
309: /* current work. Reestablish invariants as cheaply as */
310: /* possible. */
311: GC_invalidate_mark_state();
312: GC_unpromote_black_lists();
313: } /* else we claim the world is already still consistent. We'll */
314: /* finish incrementally. */
315: return(FALSE);
316: }
317: GC_finish_collection();
318: return(TRUE);
319: }
320:
321:
322:
323: /*
324: * Perform n units of garbage collection work. A unit is intended to touch
325: * roughly GC_RATE pages. Every once in a while, we do more than that.
326: * This needa to be a fairly large number with our current incremental
327: * GC strategy, since otherwise we allocate too much during GC, and the
328: * cleanup gets expensive.
329: */
330: # define GC_RATE 10
331: # define MAX_PRIOR_ATTEMPTS 1
332: /* Maximum number of prior attempts at world stop marking */
333: /* A value of 1 means that we finish the seconf time, no matter */
334: /* how long it takes. Doesn't count the initial root scan */
335: /* for a full GC. */
336:
337: int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
338: /* that we have made. */
339:
340: void GC_collect_a_little_inner(n)
341: int n;
342: {
343: register int i;
344:
345: if (GC_incremental && GC_collection_in_progress()) {
346: for (i = GC_deficit; i < GC_RATE*n; i++) {
347: if (GC_mark_some((ptr_t)0)) {
348: /* Need to finish a collection */
349: # ifdef SAVE_CALL_CHAIN
350: GC_save_callers(GC_last_stack);
351: # endif
352: if (GC_n_attempts < MAX_PRIOR_ATTEMPTS) {
353: GET_TIME(GC_start_time);
354: if (!GC_stopped_mark(GC_timeout_stop_func)) {
355: GC_n_attempts++;
356: break;
357: }
358: } else {
359: (void)GC_stopped_mark(GC_never_stop_func);
360: }
361: GC_finish_collection();
362: break;
363: }
364: }
365: if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
366: if (GC_deficit < 0) GC_deficit = 0;
367: } else {
368: GC_maybe_gc();
369: }
370: }
371:
372: int GC_collect_a_little GC_PROTO(())
373: {
374: int result;
375: DCL_LOCK_STATE;
376:
377: DISABLE_SIGNALS();
378: LOCK();
379: GC_collect_a_little_inner(1);
380: result = (int)GC_collection_in_progress();
381: UNLOCK();
382: ENABLE_SIGNALS();
383: return(result);
384: }
385:
386: /*
387: * Assumes lock is held, signals are disabled.
388: * We stop the world.
389: * If stop_func() ever returns TRUE, we may fail and return FALSE.
390: * Increment GC_gc_no if we succeed.
391: */
392: GC_bool GC_stopped_mark(stop_func)
393: GC_stop_func stop_func;
394: {
395: register int i;
396: int dummy;
397: # ifdef PRINTSTATS
398: CLOCK_TYPE start_time, current_time;
399: # endif
400:
401: STOP_WORLD();
402: # ifdef PRINTSTATS
403: GET_TIME(start_time);
404: GC_printf1("--> Marking for collection %lu ",
405: (unsigned long) GC_gc_no + 1);
406: GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
407: (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
408: (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
409: # endif
410:
411: /* Mark from all roots. */
412: /* Minimize junk left in my registers and on the stack */
413: GC_clear_a_few_frames();
414: GC_noop(0,0,0,0,0,0);
415: GC_initiate_gc();
416: for(i = 0;;i++) {
417: if ((*stop_func)()) {
418: # ifdef PRINTSTATS
419: GC_printf0("Abandoned stopped marking after ");
420: GC_printf1("%lu iterations\n",
421: (unsigned long)i);
422: # endif
423: GC_deficit = i; /* Give the mutator a chance. */
424: START_WORLD();
425: return(FALSE);
426: }
427: if (GC_mark_some((ptr_t)(&dummy))) break;
428: }
429:
430: GC_gc_no++;
431: # ifdef PRINTSTATS
432: GC_printf2("Collection %lu reclaimed %ld bytes",
433: (unsigned long) GC_gc_no - 1,
434: (long)WORDS_TO_BYTES(GC_mem_found));
435: GC_printf1(" ---> heapsize = %lu bytes\n",
436: (unsigned long) GC_heapsize);
437: /* Printf arguments may be pushed in funny places. Clear the */
438: /* space. */
439: GC_printf0("");
440: # endif
441:
442: /* Check all debugged objects for consistency */
443: if (GC_debugging_started) {
444: (*GC_check_heap)();
445: }
446:
447: # ifdef PRINTTIMES
448: GET_TIME(current_time);
449: GC_printf1("World-stopped marking took %lu msecs\n",
450: MS_TIME_DIFF(current_time,start_time));
451: # endif
452: START_WORLD();
453: return(TRUE);
454: }
455:
456:
457: /* Finish up a collection. Assumes lock is held, signals are disabled, */
458: /* but the world is otherwise running. */
459: void GC_finish_collection()
460: {
461: # ifdef PRINTTIMES
462: CLOCK_TYPE start_time;
463: CLOCK_TYPE finalize_time;
464: CLOCK_TYPE done_time;
465:
466: GET_TIME(start_time);
467: finalize_time = start_time;
468: # endif
469:
470: # ifdef GATHERSTATS
471: GC_mem_found = 0;
472: # endif
473: # ifdef FIND_LEAK
474: /* Mark all objects on the free list. All objects should be */
475: /* marked when we're done. */
476: {
477: register word size; /* current object size */
478: register ptr_t p; /* pointer to current object */
479: register struct hblk * h; /* pointer to block containing *p */
480: register hdr * hhdr;
481: register int word_no; /* "index" of *p in *q */
482: int kind;
483:
484: for (kind = 0; kind < GC_n_kinds; kind++) {
485: for (size = 1; size <= MAXOBJSZ; size++) {
486: for (p= GC_obj_kinds[kind].ok_freelist[size];
487: p != 0; p=obj_link(p)){
488: h = HBLKPTR(p);
489: hhdr = HDR(h);
490: word_no = (((word *)p) - ((word *)h));
491: set_mark_bit_from_hdr(hhdr, word_no);
492: }
493: }
494: }
495: }
496: /* Check that everything is marked */
497: GC_start_reclaim(TRUE);
498: # else
499:
500: GC_finalize();
501: # ifdef STUBBORN_ALLOC
502: GC_clean_changing_list();
503: # endif
504:
505: # ifdef PRINTTIMES
506: GET_TIME(finalize_time);
507: # endif
508:
509: /* Clear free list mark bits, in case they got accidentally marked */
510: /* Note: HBLKPTR(p) == pointer to head of block containing *p */
511: /* Also subtract memory remaining from GC_mem_found count. */
512: /* Note that composite objects on free list are cleared. */
513: /* Thus accidentally marking a free list is not a problem; only */
514: /* objects on the list itself will be marked, and that's fixed here. */
515: {
516: register word size; /* current object size */
517: register ptr_t p; /* pointer to current object */
518: register struct hblk * h; /* pointer to block containing *p */
519: register hdr * hhdr;
520: register int word_no; /* "index" of *p in *q */
521: int kind;
522:
523: for (kind = 0; kind < GC_n_kinds; kind++) {
524: for (size = 1; size <= MAXOBJSZ; size++) {
525: for (p= GC_obj_kinds[kind].ok_freelist[size];
526: p != 0; p=obj_link(p)){
527: h = HBLKPTR(p);
528: hhdr = HDR(h);
529: word_no = (((word *)p) - ((word *)h));
530: clear_mark_bit_from_hdr(hhdr, word_no);
531: # ifdef GATHERSTATS
532: GC_mem_found -= size;
533: # endif
534: }
535: }
536: }
537: }
538:
539:
540: # ifdef PRINTSTATS
541: GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
542: (long)WORDS_TO_BYTES(GC_mem_found));
543: # endif
544:
545: /* Reconstruct free lists to contain everything not marked */
546: GC_start_reclaim(FALSE);
547:
548: # endif /* !FIND_LEAK */
549:
550: # ifdef PRINTSTATS
551: GC_printf2(
552: "Immediately reclaimed %ld bytes in heap of size %lu bytes\n",
553: (long)WORDS_TO_BYTES(GC_mem_found),
554: (unsigned long)GC_heapsize);
555: GC_printf2("%lu (atomic) + %lu (composite) collectable bytes in use\n",
556: (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
557: (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
558: # endif
559:
560: GC_n_attempts = 0;
561: /* Reset or increment counters for next cycle */
562: GC_words_allocd_before_gc += GC_words_allocd;
563: GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
564: GC_words_allocd = 0;
565: GC_words_wasted = 0;
566: GC_mem_freed = 0;
567:
568: # ifdef PRINTTIMES
569: GET_TIME(done_time);
570: GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
571: MS_TIME_DIFF(finalize_time,start_time),
572: MS_TIME_DIFF(done_time,finalize_time));
573: # endif
574: }
575:
576: /* Externally callable routine to invoke full, stop-world collection */
577: # if defined(__STDC__) || defined(__cplusplus)
578: int GC_try_to_collect(GC_stop_func stop_func)
579: # else
580: int GC_try_to_collect(stop_func)
581: GC_stop_func stop_func;
582: # endif
583: {
584: int result;
585: DCL_LOCK_STATE;
586:
587: GC_INVOKE_FINALIZERS();
588: DISABLE_SIGNALS();
589: LOCK();
590: ENTER_GC();
591: if (!GC_is_initialized) GC_init_inner();
592: /* Minimize junk left in my registers */
593: GC_noop(0,0,0,0,0,0);
594: result = (int)GC_try_to_collect_inner(stop_func);
595: EXIT_GC();
596: UNLOCK();
597: ENABLE_SIGNALS();
598: if(result) GC_INVOKE_FINALIZERS();
599: return(result);
600: }
601:
602: void GC_gcollect GC_PROTO(())
603: {
604: GC_notify_full_gc();
605: (void)GC_try_to_collect(GC_never_stop_func);
606: }
607:
608: word GC_n_heap_sects = 0; /* Number of sections currently in heap. */
609:
610: /*
611: * Use the chunk of memory starting at p of syze bytes as part of the heap.
612: * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
613: */
614: void GC_add_to_heap(p, bytes)
615: struct hblk *p;
616: word bytes;
617: {
618: word words;
619:
620: if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
621: ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
622: }
623: if (!GC_install_header(p)) {
624: /* This is extremely unlikely. Can't add it. This will */
625: /* almost certainly result in a 0 return from the allocator, */
626: /* which is entirely appropriate. */
627: return;
628: }
629: GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
630: GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
631: GC_n_heap_sects++;
632: words = BYTES_TO_WORDS(bytes - HDR_BYTES);
633: HDR(p) -> hb_sz = words;
634: GC_freehblk(p);
635: GC_heapsize += bytes;
636: if ((ptr_t)p <= GC_least_plausible_heap_addr
637: || GC_least_plausible_heap_addr == 0) {
638: GC_least_plausible_heap_addr = (ptr_t)p - sizeof(word);
639: /* Making it a little smaller than necessary prevents */
640: /* us from getting a false hit from the variable */
641: /* itself. There's some unintentional reflection */
642: /* here. */
643: }
644: if ((ptr_t)p + bytes >= GC_greatest_plausible_heap_addr) {
645: GC_greatest_plausible_heap_addr = (ptr_t)p + bytes;
646: }
647: }
648:
649: #ifdef PRESERVE_LAST
650:
651: GC_bool GC_protect_last_block = FALSE;
652:
653: GC_bool GC_in_last_heap_sect(p)
654: ptr_t p;
655: {
656: struct HeapSect * last_heap_sect;
657: ptr_t start;
658: ptr_t end;
659:
660: if (!GC_protect_last_block) return FALSE;
661: last_heap_sect = &(GC_heap_sects[GC_n_heap_sects-1]);
662: start = last_heap_sect -> hs_start;
663: if (p < start) return FALSE;
664: end = start + last_heap_sect -> hs_bytes;
665: if (p >= end) return FALSE;
666: return TRUE;
667: }
668: #endif
669:
670: # if !defined(NO_DEBUGGING)
671: void GC_print_heap_sects()
672: {
673: register unsigned i;
674:
675: GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
676: for (i = 0; i < GC_n_heap_sects; i++) {
677: unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
678: unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
679: struct hblk *h;
680: unsigned nbl = 0;
681:
682: GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
683: start, (unsigned long)(start + len));
684: for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
685: if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
686: }
687: GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
688: (unsigned long)(len/HBLKSIZE));
689: }
690: }
691: # endif
692:
693: ptr_t GC_least_plausible_heap_addr = (ptr_t)ONES;
694: ptr_t GC_greatest_plausible_heap_addr = 0;
695:
696: ptr_t GC_max(x,y)
697: ptr_t x, y;
698: {
699: return(x > y? x : y);
700: }
701:
702: ptr_t GC_min(x,y)
703: ptr_t x, y;
704: {
705: return(x < y? x : y);
706: }
707:
708: # if defined(__STDC__) || defined(__cplusplus)
709: void GC_set_max_heap_size(GC_word n)
710: # else
711: void GC_set_max_heap_size(n)
712: GC_word n;
713: # endif
714: {
715: GC_max_heapsize = n;
716: }
717:
718: GC_word GC_max_retries = 0;
719:
720: /*
721: * this explicitly increases the size of the heap. It is used
722: * internally, but may also be invoked from GC_expand_hp by the user.
723: * The argument is in units of HBLKSIZE.
724: * Tiny values of n are rounded up.
725: * Returns FALSE on failure.
726: */
727: GC_bool GC_expand_hp_inner(n)
728: word n;
729: {
730: word bytes;
731: struct hblk * space;
732: word expansion_slop; /* Number of bytes by which we expect the */
733: /* heap to expand soon. */
734:
735: if (n < MINHINCR) n = MINHINCR;
736: bytes = n * HBLKSIZE;
737: /* Make sure bytes is a multiple of GC_page_size */
738: {
739: word mask = GC_page_size - 1;
740: bytes += mask;
741: bytes &= ~mask;
742: }
743:
744: if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
745: /* Exceeded self-imposed limit */
746: return(FALSE);
747: }
748: space = GET_MEM(bytes);
749: if( space == 0 ) {
750: return(FALSE);
751: }
752: # ifdef PRINTSTATS
753: GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
754: (unsigned long)bytes,
755: (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
756: # ifdef UNDEFINED
757: GC_printf1("Root size = %lu\n", GC_root_size);
758: GC_print_block_list(); GC_print_hblkfreelist();
759: GC_printf0("\n");
760: # endif
761: # endif
762: expansion_slop = 8 * WORDS_TO_BYTES(min_words_allocd());
763: if (5 * HBLKSIZE * MAXHINCR > expansion_slop) {
764: expansion_slop = 5 * HBLKSIZE * MAXHINCR;
765: }
766: if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
767: || GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space) {
768: /* Assume the heap is growing up */
769: GC_greatest_plausible_heap_addr =
770: GC_max(GC_greatest_plausible_heap_addr,
771: (ptr_t)space + bytes + expansion_slop);
772: } else {
773: /* Heap is growing down */
774: GC_least_plausible_heap_addr =
775: GC_min(GC_least_plausible_heap_addr,
776: (ptr_t)space - expansion_slop);
777: }
778: GC_prev_heap_addr = GC_last_heap_addr;
779: GC_last_heap_addr = (ptr_t)space;
780: GC_add_to_heap(space, bytes);
781: return(TRUE);
782: }
783:
784: /* Really returns a bool, but it's externally visible, so that's clumsy. */
785: /* Arguments is in bytes. */
786: # if defined(__STDC__) || defined(__cplusplus)
787: int GC_expand_hp(size_t bytes)
788: # else
789: int GC_expand_hp(bytes)
790: size_t bytes;
791: # endif
792: {
793: int result;
794: DCL_LOCK_STATE;
795:
796: DISABLE_SIGNALS();
797: LOCK();
798: if (!GC_is_initialized) GC_init_inner();
799: result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
800: # ifdef PRESERVE_LAST
801: if (result) GC_protect_last_block = FALSE;
802: # endif
803: UNLOCK();
804: ENABLE_SIGNALS();
805: return(result);
806: }
807:
808: unsigned GC_fail_count = 0;
809: /* How many consecutive GC/expansion failures? */
810: /* Reset by GC_allochblk. */
811:
812: GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
813: word needed_blocks;
814: GC_bool ignore_off_page;
815: {
816:
817: if (!GC_incremental && !GC_dont_gc && GC_should_collect()) {
818: GC_notify_full_gc();
819: GC_gcollect_inner();
820: } else {
821: word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
822: + needed_blocks;
823:
824: if (blocks_to_get > MAXHINCR) {
825: word slop;
826:
827: if (ignore_off_page) {
828: slop = 4;
829: } else {
830: slop = 2*divHBLKSZ(BL_LIMIT);
831: if (slop > needed_blocks) slop = needed_blocks;
832: }
833: if (needed_blocks + slop > MAXHINCR) {
834: blocks_to_get = needed_blocks + slop;
835: } else {
836: blocks_to_get = MAXHINCR;
837: }
838: }
839: if (!GC_expand_hp_inner(blocks_to_get)
840: && !GC_expand_hp_inner(needed_blocks)) {
841: if (GC_fail_count++ < GC_max_retries) {
842: WARN("Out of Memory! Trying to continue ...\n", 0);
843: GC_notify_full_gc();
844: GC_gcollect_inner();
845: } else {
846: WARN("Out of Memory! Returning NIL!\n", 0);
847: return(FALSE);
848: }
849: } else {
850: # ifdef PRINTSTATS
851: if (GC_fail_count) {
852: GC_printf0("Memory available again ...\n");
853: }
854: # endif
855: # ifdef PRESERVE_LAST
856: if (needed_blocks > 1) GC_protect_last_block = TRUE;
857: /* We were forced to expand the heap as the result */
858: /* of a large block allocation. Avoid breaking up */
859: /* new block into small pieces. */
860: # endif
861: }
862: }
863: return(TRUE);
864: }
865:
866: /*
867: * Make sure the object free list for sz is not empty.
868: * Return a pointer to the first object on the free list.
869: * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
870: * Assumes we hold the allocator lock and signals are disabled.
871: *
872: */
873: ptr_t GC_allocobj(sz, kind)
874: word sz;
875: int kind;
876: {
877: register ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
878:
879: if (sz == 0) return(0);
880:
881: while (*flh == 0) {
882: ENTER_GC();
883: /* Do our share of marking work */
884: if(GC_incremental && !GC_dont_gc) GC_collect_a_little_inner(1);
885: /* Sweep blocks for objects of this size */
886: GC_continue_reclaim(sz, kind);
887: EXIT_GC();
888: if (*flh == 0) {
889: GC_new_hblk(sz, kind);
890: }
891: if (*flh == 0) {
892: ENTER_GC();
893: if (!GC_collect_or_expand((word)1,FALSE)) {
894: EXIT_GC();
895: return(0);
896: }
897: EXIT_GC();
898: }
899: }
900:
901: return(*flh);
902: }
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