Annotation of OpenXM_contrib2/asir2000/gc/alloc.c, Revision 1.2
1.1 noro 1: /*
2: * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
1.2 ! noro 3: * Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
1.1 noro 4: * Copyright (c) 1998 by Silicon Graphics. All rights reserved.
1.2 ! noro 5: * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
1.1 noro 6: *
7: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
9: *
10: * Permission is hereby granted to use or copy this program
11: * for any purpose, provided the above notices are retained on all copies.
12: * Permission to modify the code and to distribute modified code is granted,
13: * provided the above notices are retained, and a notice that the code was
14: * modified is included with the above copyright notice.
15: *
16: */
17:
18:
19: # include "gc_priv.h"
20:
21: # include <stdio.h>
22: # ifndef MACOS
23: # include <signal.h>
24: # include <sys/types.h>
25: # endif
26:
27: void GC_timerstart(),GC_timerstop();
28:
29: /*
30: * Separate free lists are maintained for different sized objects
31: * up to MAXOBJSZ.
32: * The call GC_allocobj(i,k) ensures that the freelist for
33: * kind k objects of size i points to a non-empty
34: * free list. It returns a pointer to the first entry on the free list.
35: * In a single-threaded world, GC_allocobj may be called to allocate
36: * an object of (small) size i as follows:
37: *
38: * opp = &(GC_objfreelist[i]);
39: * if (*opp == 0) GC_allocobj(i, NORMAL);
40: * ptr = *opp;
41: * *opp = obj_link(ptr);
42: *
43: * Note that this is very fast if the free list is non-empty; it should
44: * only involve the execution of 4 or 5 simple instructions.
45: * All composite objects on freelists are cleared, except for
46: * their first word.
47: */
48:
49: /*
50: * The allocator uses GC_allochblk to allocate large chunks of objects.
51: * These chunks all start on addresses which are multiples of
52: * HBLKSZ. Each allocated chunk has an associated header,
53: * which can be located quickly based on the address of the chunk.
54: * (See headers.c for details.)
55: * This makes it possible to check quickly whether an
56: * arbitrary address corresponds to an object administered by the
57: * allocator.
58: */
59:
60: word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */
61:
62: word GC_gc_no = 0;
63:
64: #ifndef SMALL_CONFIG
65: int GC_incremental = 0; /* By default, stop the world. */
66: #endif
67:
1.2 ! noro 68: int GC_full_freq = 19; /* Every 20th collection is a full */
! 69: /* collection, whether we need it */
! 70: /* or not. */
! 71:
! 72: GC_bool GC_need_full_gc = FALSE;
! 73: /* Need full GC do to heap growth. */
! 74:
! 75: #define USED_HEAP_SIZE (GC_heapsize - GC_large_free_bytes)
! 76:
! 77: word GC_used_heap_size_after_full = 0;
1.1 noro 78:
79: char * GC_copyright[] =
80: {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
81: "Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ",
82: "Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ",
83: "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
84: " EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.",
85: "See source code for details." };
86:
87: # include "version.h"
88:
89: /* some more variables */
90:
91: extern signed_word GC_mem_found; /* Number of reclaimed longwords */
92: /* after garbage collection */
93:
94: GC_bool GC_dont_expand = 0;
95:
96: word GC_free_space_numerator = 1;
97: word GC_free_space_divisor = 3;
98:
99: extern GC_bool GC_collection_in_progress();
100: /* Collection is in progress, or was abandoned. */
101:
102: int GC_never_stop_func GC_PROTO((void)) { return(0); }
103:
104: CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
105: /* used only in GC_timeout_stop_func. */
106:
107: int GC_n_attempts = 0; /* Number of attempts at finishing */
108: /* collection within TIME_LIMIT */
109:
110: #ifdef SMALL_CONFIG
111: # define GC_timeout_stop_func GC_never_stop_func
112: #else
113: int GC_timeout_stop_func GC_PROTO((void))
114: {
115: CLOCK_TYPE current_time;
116: static unsigned count = 0;
117: unsigned long time_diff;
118:
119: if ((count++ & 3) != 0) return(0);
120: GET_TIME(current_time);
121: time_diff = MS_TIME_DIFF(current_time,GC_start_time);
122: if (time_diff >= TIME_LIMIT) {
123: # ifdef PRINTSTATS
124: GC_printf0("Abandoning stopped marking after ");
125: GC_printf1("%lu msecs", (unsigned long)time_diff);
126: GC_printf1("(attempt %d)\n", (unsigned long) GC_n_attempts);
127: # endif
128: return(1);
129: }
130: return(0);
131: }
132: #endif /* !SMALL_CONFIG */
133:
134: /* Return the minimum number of words that must be allocated between */
135: /* collections to amortize the collection cost. */
136: static word min_words_allocd()
137: {
138: # ifdef THREADS
139: /* We punt, for now. */
140: register signed_word stack_size = 10000;
141: # else
142: int dummy;
143: register signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
144: # endif
145: word total_root_size; /* includes double stack size, */
146: /* since the stack is expensive */
147: /* to scan. */
148: word scan_size; /* Estimate of memory to be scanned */
149: /* during normal GC. */
150:
151: if (stack_size < 0) stack_size = -stack_size;
152: total_root_size = 2 * stack_size + GC_root_size;
153: scan_size = BYTES_TO_WORDS(GC_heapsize - GC_large_free_bytes
154: + (GC_large_free_bytes >> 2)
155: /* use a bit more of large empty heap */
156: + total_root_size);
157: if (GC_incremental) {
158: return (scan_size*GC_free_space_numerator) / (2 * GC_free_space_divisor);
159: } else {
160: return (scan_size*GC_free_space_numerator) / GC_free_space_divisor;
161: }
162: }
163:
164: /* Return the number of words allocated, adjusted for explicit storage */
165: /* management, etc.. This number is used in deciding when to trigger */
166: /* collections. */
167: word GC_adj_words_allocd()
168: {
169: register signed_word result;
170: register signed_word expl_managed =
171: BYTES_TO_WORDS((long)GC_non_gc_bytes
172: - (long)GC_non_gc_bytes_at_gc);
173:
174: /* Don't count what was explicitly freed, or newly allocated for */
175: /* explicit management. Note that deallocating an explicitly */
176: /* managed object should not alter result, assuming the client */
177: /* is playing by the rules. */
178: result = (signed_word)GC_words_allocd
179: - (signed_word)GC_mem_freed - expl_managed;
180: if (result > (signed_word)GC_words_allocd) {
181: result = GC_words_allocd;
182: /* probably client bug or unfortunate scheduling */
183: }
184: result += GC_words_finalized;
185: /* We count objects enqueued for finalization as though they */
186: /* had been reallocated this round. Finalization is user */
187: /* visible progress. And if we don't count this, we have */
188: /* stability problems for programs that finalize all objects. */
189: result += GC_words_wasted;
190: /* This doesn't reflect useful work. But if there is lots of */
191: /* new fragmentation, the same is probably true of the heap, */
192: /* and the collection will be correspondingly cheaper. */
193: if (result < (signed_word)(GC_words_allocd >> 3)) {
194: /* Always count at least 1/8 of the allocations. We don't want */
195: /* to collect too infrequently, since that would inhibit */
196: /* coalescing of free storage blocks. */
197: /* This also makes us partially robust against client bugs. */
198: return(GC_words_allocd >> 3);
199: } else {
200: return(result);
201: }
202: }
203:
204:
205: /* Clear up a few frames worth of garbage left at the top of the stack. */
206: /* This is used to prevent us from accidentally treating garbade left */
207: /* on the stack by other parts of the collector as roots. This */
208: /* differs from the code in misc.c, which actually tries to keep the */
209: /* stack clear of long-lived, client-generated garbage. */
210: void GC_clear_a_few_frames()
211: {
212: # define NWORDS 64
213: word frames[NWORDS];
214: register int i;
215:
216: for (i = 0; i < NWORDS; i++) frames[i] = 0;
217: }
218:
219: /* Have we allocated enough to amortize a collection? */
220: GC_bool GC_should_collect()
221: {
222: return(GC_adj_words_allocd() >= min_words_allocd());
223: }
224:
1.2 ! noro 225:
1.1 noro 226: void GC_notify_full_gc()
227: {
228: if (GC_start_call_back != (void (*)())0) {
229: (*GC_start_call_back)();
230: }
231: }
232:
1.2 ! noro 233: GC_bool GC_is_full_gc = FALSE;
! 234:
1.1 noro 235: /*
236: * Initiate a garbage collection if appropriate.
237: * Choose judiciously
238: * between partial, full, and stop-world collections.
239: * Assumes lock held, signals disabled.
240: */
241: void GC_maybe_gc()
242: {
243: static int n_partial_gcs = 0;
244:
245: if (GC_should_collect()) {
246: if (!GC_incremental) {
247: GC_notify_full_gc();
248: GC_gcollect_inner();
249: n_partial_gcs = 0;
250: return;
1.2 ! noro 251: } else if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
1.1 noro 252: # ifdef PRINTSTATS
253: GC_printf2(
254: "***>Full mark for collection %lu after %ld allocd bytes\n",
255: (unsigned long) GC_gc_no+1,
256: (long)WORDS_TO_BYTES(GC_words_allocd));
257: # endif
258: GC_promote_black_lists();
259: (void)GC_reclaim_all((GC_stop_func)0, TRUE);
260: GC_clear_marks();
261: n_partial_gcs = 0;
262: GC_notify_full_gc();
1.2 ! noro 263: GC_is_full_gc = TRUE;
1.1 noro 264: } else {
265: n_partial_gcs++;
266: }
267: /* We try to mark with the world stopped. */
268: /* If we run out of time, this turns into */
269: /* incremental marking. */
270: GET_TIME(GC_start_time);
271: if (GC_stopped_mark(GC_timeout_stop_func)) {
272: # ifdef SAVE_CALL_CHAIN
273: GC_save_callers(GC_last_stack);
274: # endif
275: GC_finish_collection();
276: } else {
1.2 ! noro 277: if (!GC_is_full_gc) {
1.1 noro 278: /* Count this as the first attempt */
279: GC_n_attempts++;
280: }
281: }
282: }
283: }
284:
285:
286: /*
287: * Stop the world garbage collection. Assumes lock held, signals disabled.
288: * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
289: */
290: GC_bool GC_try_to_collect_inner(stop_func)
291: GC_stop_func stop_func;
292: {
293: if (GC_incremental && GC_collection_in_progress()) {
294: # ifdef PRINTSTATS
295: GC_printf0(
296: "GC_try_to_collect_inner: finishing collection in progress\n");
297: # endif /* PRINTSTATS */
298: /* Just finish collection already in progress. */
299: while(GC_collection_in_progress()) {
300: if (stop_func()) return(FALSE);
301: GC_collect_a_little_inner(1);
302: }
303: }
304: # ifdef PRINTSTATS
305: GC_printf2(
306: "Initiating full world-stop collection %lu after %ld allocd bytes\n",
307: (unsigned long) GC_gc_no+1,
308: (long)WORDS_TO_BYTES(GC_words_allocd));
309: # endif
310: GC_promote_black_lists();
311: /* Make sure all blocks have been reclaimed, so sweep routines */
312: /* don't see cleared mark bits. */
313: /* If we're guaranteed to finish, then this is unnecessary. */
314: if (stop_func != GC_never_stop_func
315: && !GC_reclaim_all(stop_func, FALSE)) {
316: /* Aborted. So far everything is still consistent. */
317: return(FALSE);
318: }
319: GC_invalidate_mark_state(); /* Flush mark stack. */
320: GC_clear_marks();
321: # ifdef SAVE_CALL_CHAIN
322: GC_save_callers(GC_last_stack);
323: # endif
1.2 ! noro 324: GC_is_full_gc = TRUE;
1.1 noro 325: if (!GC_stopped_mark(stop_func)) {
326: if (!GC_incremental) {
327: /* We're partially done and have no way to complete or use */
328: /* current work. Reestablish invariants as cheaply as */
329: /* possible. */
330: GC_invalidate_mark_state();
331: GC_unpromote_black_lists();
332: } /* else we claim the world is already still consistent. We'll */
333: /* finish incrementally. */
334: return(FALSE);
335: }
336: GC_finish_collection();
337: return(TRUE);
338: }
339:
340:
341:
342: /*
343: * Perform n units of garbage collection work. A unit is intended to touch
344: * roughly GC_RATE pages. Every once in a while, we do more than that.
345: * This needa to be a fairly large number with our current incremental
346: * GC strategy, since otherwise we allocate too much during GC, and the
347: * cleanup gets expensive.
348: */
349: # define GC_RATE 10
350: # define MAX_PRIOR_ATTEMPTS 1
351: /* Maximum number of prior attempts at world stop marking */
352: /* A value of 1 means that we finish the seconf time, no matter */
353: /* how long it takes. Doesn't count the initial root scan */
354: /* for a full GC. */
355:
356: int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
357: /* that we have made. */
358:
359: void GC_collect_a_little_inner(n)
360: int n;
361: {
362: register int i;
363:
364: if (GC_incremental && GC_collection_in_progress()) {
365: for (i = GC_deficit; i < GC_RATE*n; i++) {
366: if (GC_mark_some((ptr_t)0)) {
367: /* Need to finish a collection */
368: # ifdef SAVE_CALL_CHAIN
369: GC_save_callers(GC_last_stack);
370: # endif
371: if (GC_n_attempts < MAX_PRIOR_ATTEMPTS) {
372: GET_TIME(GC_start_time);
373: if (!GC_stopped_mark(GC_timeout_stop_func)) {
374: GC_n_attempts++;
375: break;
376: }
377: } else {
378: (void)GC_stopped_mark(GC_never_stop_func);
379: }
380: GC_finish_collection();
381: break;
382: }
383: }
384: if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
385: if (GC_deficit < 0) GC_deficit = 0;
386: } else {
387: GC_maybe_gc();
388: }
389: }
390:
391: int GC_collect_a_little GC_PROTO(())
392: {
393: int result;
394: DCL_LOCK_STATE;
395:
396: DISABLE_SIGNALS();
397: LOCK();
398: GC_collect_a_little_inner(1);
399: result = (int)GC_collection_in_progress();
400: UNLOCK();
401: ENABLE_SIGNALS();
402: return(result);
403: }
404:
405: /*
406: * Assumes lock is held, signals are disabled.
407: * We stop the world.
408: * If stop_func() ever returns TRUE, we may fail and return FALSE.
409: * Increment GC_gc_no if we succeed.
410: */
411: GC_bool GC_stopped_mark(stop_func)
412: GC_stop_func stop_func;
413: {
414: register int i;
415: int dummy;
416: # ifdef PRINTSTATS
417: CLOCK_TYPE start_time, current_time;
418: # endif
419:
420: STOP_WORLD();
421: GC_timerstart();
422: # ifdef PRINTSTATS
423: GET_TIME(start_time);
424: GC_printf1("--> Marking for collection %lu ",
425: (unsigned long) GC_gc_no + 1);
426: GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
427: (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
428: (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
429: # endif
430:
431: /* Mark from all roots. */
432: /* Minimize junk left in my registers and on the stack */
433: GC_clear_a_few_frames();
434: GC_noop(0,0,0,0,0,0);
435: GC_initiate_gc();
436: for(i = 0;;i++) {
437: if ((*stop_func)()) {
438: # ifdef PRINTSTATS
439: GC_printf0("Abandoned stopped marking after ");
440: GC_printf1("%lu iterations\n",
441: (unsigned long)i);
442: # endif
443: GC_timerstop();
444: GC_deficit = i; /* Give the mutator a chance. */
445: START_WORLD();
446: return(FALSE);
447: }
448: if (GC_mark_some((ptr_t)(&dummy))) break;
449: }
450:
451: GC_gc_no++;
452: # ifdef PRINTSTATS
453: GC_printf2("Collection %lu reclaimed %ld bytes",
454: (unsigned long) GC_gc_no - 1,
455: (long)WORDS_TO_BYTES(GC_mem_found));
456: GC_printf1(" ---> heapsize = %lu bytes\n",
457: (unsigned long) GC_heapsize);
458: /* Printf arguments may be pushed in funny places. Clear the */
459: /* space. */
460: GC_printf0("");
461: # endif
462:
463: /* Check all debugged objects for consistency */
464: if (GC_debugging_started) {
465: (*GC_check_heap)();
466: }
467:
468: # ifdef PRINTTIMES
469: GET_TIME(current_time);
470: GC_printf1("World-stopped marking took %lu msecs\n",
471: MS_TIME_DIFF(current_time,start_time));
472: # endif
473: GC_timerstop();
474: START_WORLD();
475: return(TRUE);
476: }
477:
478:
479: /* Finish up a collection. Assumes lock is held, signals are disabled, */
480: /* but the world is otherwise running. */
481: void GC_finish_collection()
482: {
483: # ifdef PRINTTIMES
484: CLOCK_TYPE start_time;
485: CLOCK_TYPE finalize_time;
486: CLOCK_TYPE done_time;
487:
488: GET_TIME(start_time);
489: finalize_time = start_time;
490: # endif
491: GC_timerstart();
492:
493: # ifdef GATHERSTATS
494: GC_mem_found = 0;
495: # endif
1.2 ! noro 496: if (GC_find_leak) {
1.1 noro 497: /* Mark all objects on the free list. All objects should be */
498: /* marked when we're done. */
499: {
500: register word size; /* current object size */
501: register ptr_t p; /* pointer to current object */
502: register struct hblk * h; /* pointer to block containing *p */
503: register hdr * hhdr;
504: register int word_no; /* "index" of *p in *q */
505: int kind;
506:
507: for (kind = 0; kind < GC_n_kinds; kind++) {
508: for (size = 1; size <= MAXOBJSZ; size++) {
509: for (p= GC_obj_kinds[kind].ok_freelist[size];
510: p != 0; p=obj_link(p)){
511: h = HBLKPTR(p);
512: hhdr = HDR(h);
513: word_no = (((word *)p) - ((word *)h));
514: set_mark_bit_from_hdr(hhdr, word_no);
515: }
516: }
517: }
518: }
519: GC_start_reclaim(TRUE);
1.2 ! noro 520: /* The above just checks; it doesn't really reclaim anything. */
! 521: }
! 522:
! 523: GC_finalize();
! 524: # ifdef STUBBORN_ALLOC
! 525: GC_clean_changing_list();
! 526: # endif
! 527:
! 528: # ifdef PRINTTIMES
! 529: GET_TIME(finalize_time);
! 530: # endif
1.1 noro 531:
1.2 ! noro 532: /* Clear free list mark bits, in case they got accidentally marked */
! 533: /* Note: HBLKPTR(p) == pointer to head of block containing *p */
! 534: /* (or GC_find_leak is set and they were intentionally marked.) */
! 535: /* Also subtract memory remaining from GC_mem_found count. */
! 536: /* Note that composite objects on free list are cleared. */
! 537: /* Thus accidentally marking a free list is not a problem; only */
! 538: /* objects on the list itself will be marked, and that's fixed here. */
1.1 noro 539: {
540: register word size; /* current object size */
541: register ptr_t p; /* pointer to current object */
542: register struct hblk * h; /* pointer to block containing *p */
543: register hdr * hhdr;
544: register int word_no; /* "index" of *p in *q */
545: int kind;
546:
547: for (kind = 0; kind < GC_n_kinds; kind++) {
548: for (size = 1; size <= MAXOBJSZ; size++) {
549: for (p= GC_obj_kinds[kind].ok_freelist[size];
550: p != 0; p=obj_link(p)){
551: h = HBLKPTR(p);
552: hhdr = HDR(h);
553: word_no = (((word *)p) - ((word *)h));
554: clear_mark_bit_from_hdr(hhdr, word_no);
555: # ifdef GATHERSTATS
556: GC_mem_found -= size;
557: # endif
558: }
559: }
560: }
561: }
562:
563:
1.2 ! noro 564: # ifdef PRINTSTATS
1.1 noro 565: GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
566: (long)WORDS_TO_BYTES(GC_mem_found));
1.2 ! noro 567: # endif
1.1 noro 568: /* Reconstruct free lists to contain everything not marked */
1.2 ! noro 569: GC_start_reclaim(FALSE);
! 570: if (GC_is_full_gc) {
! 571: GC_used_heap_size_after_full = USED_HEAP_SIZE;
! 572: GC_need_full_gc = FALSE;
! 573: } else {
! 574: GC_need_full_gc =
! 575: BYTES_TO_WORDS(USED_HEAP_SIZE - GC_used_heap_size_after_full)
! 576: > min_words_allocd();
! 577: }
1.1 noro 578:
579: # ifdef PRINTSTATS
580: GC_printf2(
581: "Immediately reclaimed %ld bytes in heap of size %lu bytes",
582: (long)WORDS_TO_BYTES(GC_mem_found),
583: (unsigned long)GC_heapsize);
584: # ifdef USE_MUNMAP
585: GC_printf1("(%lu unmapped)", GC_unmapped_bytes);
586: # endif
587: GC_printf2(
588: "\n%lu (atomic) + %lu (composite) collectable bytes in use\n",
589: (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
590: (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
591: # endif
592:
593: GC_n_attempts = 0;
1.2 ! noro 594: GC_is_full_gc = FALSE;
1.1 noro 595: /* Reset or increment counters for next cycle */
596: GC_words_allocd_before_gc += GC_words_allocd;
597: GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
598: GC_words_allocd = 0;
599: GC_words_wasted = 0;
600: GC_mem_freed = 0;
601:
602: # ifdef USE_MUNMAP
603: GC_unmap_old();
604: # endif
605: # ifdef PRINTTIMES
606: GET_TIME(done_time);
607: GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
608: MS_TIME_DIFF(finalize_time,start_time),
609: MS_TIME_DIFF(done_time,finalize_time));
610: # endif
611: GC_timerstop();
612: }
613:
614: /* Externally callable routine to invoke full, stop-world collection */
615: # if defined(__STDC__) || defined(__cplusplus)
616: int GC_try_to_collect(GC_stop_func stop_func)
617: # else
618: int GC_try_to_collect(stop_func)
619: GC_stop_func stop_func;
620: # endif
621: {
622: int result;
623: DCL_LOCK_STATE;
624:
625: GC_INVOKE_FINALIZERS();
626: DISABLE_SIGNALS();
627: LOCK();
628: ENTER_GC();
629: if (!GC_is_initialized) GC_init_inner();
630: /* Minimize junk left in my registers */
631: GC_noop(0,0,0,0,0,0);
632: result = (int)GC_try_to_collect_inner(stop_func);
633: EXIT_GC();
634: UNLOCK();
635: ENABLE_SIGNALS();
636: if(result) GC_INVOKE_FINALIZERS();
637: return(result);
638: }
639:
640: void GC_gcollect GC_PROTO(())
641: {
642: GC_notify_full_gc();
643: (void)GC_try_to_collect(GC_never_stop_func);
644: }
645:
646: word GC_n_heap_sects = 0; /* Number of sections currently in heap. */
647:
648: /*
649: * Use the chunk of memory starting at p of size bytes as part of the heap.
650: * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
651: */
652: void GC_add_to_heap(p, bytes)
653: struct hblk *p;
654: word bytes;
655: {
656: word words;
657: hdr * phdr;
658:
659: if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
660: ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
661: }
662: if (!GC_install_header(p)) {
663: /* This is extremely unlikely. Can't add it. This will */
664: /* almost certainly result in a 0 return from the allocator, */
665: /* which is entirely appropriate. */
666: return;
667: }
668: GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
669: GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
670: GC_n_heap_sects++;
671: words = BYTES_TO_WORDS(bytes - HDR_BYTES);
672: phdr = HDR(p);
673: phdr -> hb_sz = words;
674: phdr -> hb_map = (char *)1; /* A value != GC_invalid_map */
675: phdr -> hb_flags = 0;
676: GC_freehblk(p);
677: GC_heapsize += bytes;
678: if ((ptr_t)p <= GC_least_plausible_heap_addr
679: || GC_least_plausible_heap_addr == 0) {
680: GC_least_plausible_heap_addr = (ptr_t)p - sizeof(word);
681: /* Making it a little smaller than necessary prevents */
682: /* us from getting a false hit from the variable */
683: /* itself. There's some unintentional reflection */
684: /* here. */
685: }
686: if ((ptr_t)p + bytes >= GC_greatest_plausible_heap_addr) {
687: GC_greatest_plausible_heap_addr = (ptr_t)p + bytes;
688: }
689: }
690:
691: # if !defined(NO_DEBUGGING)
692: void GC_print_heap_sects()
693: {
694: register unsigned i;
695:
696: GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
697: for (i = 0; i < GC_n_heap_sects; i++) {
698: unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
699: unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
700: struct hblk *h;
701: unsigned nbl = 0;
702:
703: GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
704: start, (unsigned long)(start + len));
705: for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
706: if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
707: }
708: GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
709: (unsigned long)(len/HBLKSIZE));
710: }
711: }
712: # endif
713:
714: ptr_t GC_least_plausible_heap_addr = (ptr_t)ONES;
715: ptr_t GC_greatest_plausible_heap_addr = 0;
716:
717: ptr_t GC_max(x,y)
718: ptr_t x, y;
719: {
720: return(x > y? x : y);
721: }
722:
723: ptr_t GC_min(x,y)
724: ptr_t x, y;
725: {
726: return(x < y? x : y);
727: }
728:
729: # if defined(__STDC__) || defined(__cplusplus)
730: void GC_set_max_heap_size(GC_word n)
731: # else
732: void GC_set_max_heap_size(n)
733: GC_word n;
734: # endif
735: {
736: GC_max_heapsize = n;
737: }
738:
739: GC_word GC_max_retries = 0;
740:
741: /*
742: * this explicitly increases the size of the heap. It is used
743: * internally, but may also be invoked from GC_expand_hp by the user.
744: * The argument is in units of HBLKSIZE.
745: * Tiny values of n are rounded up.
746: * Returns FALSE on failure.
747: */
748: GC_bool GC_expand_hp_inner(n)
749: word n;
750: {
751: word bytes;
752: struct hblk * space;
753: word expansion_slop; /* Number of bytes by which we expect the */
754: /* heap to expand soon. */
755:
756: if (n < MINHINCR) n = MINHINCR;
757: bytes = n * HBLKSIZE;
758: /* Make sure bytes is a multiple of GC_page_size */
759: {
760: word mask = GC_page_size - 1;
761: bytes += mask;
762: bytes &= ~mask;
763: }
764:
765: if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
766: /* Exceeded self-imposed limit */
767: return(FALSE);
768: }
769: space = GET_MEM(bytes);
770: if( space == 0 ) {
771: return(FALSE);
772: }
773: # ifdef PRINTSTATS
774: GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
775: (unsigned long)bytes,
776: (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
777: # ifdef UNDEFINED
778: GC_printf1("Root size = %lu\n", GC_root_size);
779: GC_print_block_list(); GC_print_hblkfreelist();
780: GC_printf0("\n");
781: # endif
782: # endif
783: expansion_slop = 8 * WORDS_TO_BYTES(min_words_allocd());
784: if (5 * HBLKSIZE * MAXHINCR > expansion_slop) {
785: expansion_slop = 5 * HBLKSIZE * MAXHINCR;
786: }
787: if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
788: || GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space) {
789: /* Assume the heap is growing up */
790: GC_greatest_plausible_heap_addr =
791: GC_max(GC_greatest_plausible_heap_addr,
792: (ptr_t)space + bytes + expansion_slop);
793: } else {
794: /* Heap is growing down */
795: GC_least_plausible_heap_addr =
796: GC_min(GC_least_plausible_heap_addr,
797: (ptr_t)space - expansion_slop);
798: }
799: GC_prev_heap_addr = GC_last_heap_addr;
800: GC_last_heap_addr = (ptr_t)space;
801: GC_add_to_heap(space, bytes);
802: #if defined(VISUAL_LIB)
803: SendHeapSize();
804: #endif
805: return(TRUE);
806: }
807:
808: /* Really returns a bool, but it's externally visible, so that's clumsy. */
809: /* Arguments is in bytes. */
810: # if defined(__STDC__) || defined(__cplusplus)
811: int GC_expand_hp(size_t bytes)
812: # else
813: int GC_expand_hp(bytes)
814: size_t bytes;
815: # endif
816: {
817: int result;
818: DCL_LOCK_STATE;
819:
820: DISABLE_SIGNALS();
821: LOCK();
822: if (!GC_is_initialized) GC_init_inner();
823: result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
824: UNLOCK();
825: ENABLE_SIGNALS();
826: return(result);
827: }
828:
829: unsigned GC_fail_count = 0;
830: /* How many consecutive GC/expansion failures? */
831: /* Reset by GC_allochblk. */
832:
833: GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
834: word needed_blocks;
835: GC_bool ignore_off_page;
836: {
837: if (!GC_incremental && !GC_dont_gc && GC_should_collect()) {
838: GC_notify_full_gc();
839: GC_gcollect_inner();
840: } else {
841: word blocks_to_get = (GC_heapsize*GC_free_space_numerator)/(HBLKSIZE*GC_free_space_divisor)
842: + needed_blocks;
843:
844: if (blocks_to_get > MAXHINCR) {
845: word slop;
846:
847: if (ignore_off_page) {
848: slop = 4;
849: } else {
850: slop = 2*divHBLKSZ(BL_LIMIT);
851: if (slop > needed_blocks) slop = needed_blocks;
852: }
853: if (needed_blocks + slop > MAXHINCR) {
854: blocks_to_get = needed_blocks + slop;
855: } else {
856: blocks_to_get = MAXHINCR;
857: }
858: }
859: if (!GC_expand_hp_inner(blocks_to_get)
860: && !GC_expand_hp_inner(needed_blocks)) {
861: if (GC_fail_count++ < GC_max_retries) {
862: WARN("Out of Memory! Trying to continue ...\n", 0);
863: GC_notify_full_gc();
864: GC_gcollect_inner();
865: } else {
866: WARN("Out of Memory! Returning NIL!\n", 0);
867: return(FALSE);
868: }
869: } else {
870: # ifdef PRINTSTATS
871: if (GC_fail_count) {
872: GC_printf0("Memory available again ...\n");
873: }
874: # endif
875: }
876: }
877: return(TRUE);
878: }
879:
880: /*
881: * Make sure the object free list for sz is not empty.
882: * Return a pointer to the first object on the free list.
883: * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
884: * Assumes we hold the allocator lock and signals are disabled.
885: *
886: */
887: ptr_t GC_allocobj(sz, kind)
888: word sz;
889: int kind;
890: {
891: register ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
892:
893: if (sz == 0) return(0);
894:
895: #if defined(VISUAL)
896: {
897: #include <signal.h>
898: extern int recv_intr;
899: if ( recv_intr ) {
900: if ( recv_intr == 1 ) {
901: recv_intr = 0;
902: int_handler();
903: } else {
904: recv_intr = 0;
905: ox_usr1_handler(0);
906: }
907: }
908: }
909: #endif
910: while (*flh == 0) {
911: ENTER_GC();
912: /* Do our share of marking work */
913: if(GC_incremental && !GC_dont_gc) GC_collect_a_little_inner(1);
914: /* Sweep blocks for objects of this size */
915: GC_continue_reclaim(sz, kind);
916: EXIT_GC();
917: if (*flh == 0) {
918: GC_new_hblk(sz, kind);
919: }
920: if (*flh == 0) {
921: ENTER_GC();
922: if (!GC_collect_or_expand((word)1,FALSE)) {
923: EXIT_GC();
924: return(0);
925: }
926: EXIT_GC();
927: }
928: }
929:
930: return(*flh);
931: }
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