source: trunk/gc6.8/finalize.c@ 360

Last change on this file since 360 was 132, checked in by cinc, 19 years ago

Boehm-Demers-Weiser garbage collector. Single-threaded for OS/2.
File size: 26.7 KB
Line 
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) 1996-1999 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/* Boehm, February 1, 1996 1:19 pm PST */
16# define I_HIDE_POINTERS
17# include "private/gc_pmark.h"
18
19# ifdef FINALIZE_ON_DEMAND
20 int GC_finalize_on_demand = 1;
21# else
22 int GC_finalize_on_demand = 0;
23# endif
24
25# ifdef JAVA_FINALIZATION
26 int GC_java_finalization = 1;
27# else
28 int GC_java_finalization = 0;
29# endif
30
31/* Type of mark procedure used for marking from finalizable object. */
32/* This procedure normally does not mark the object, only its */
33/* descendents. */
34typedef void finalization_mark_proc(/* ptr_t finalizable_obj_ptr */);
35
36# define HASH3(addr,size,log_size) \
37 ((((word)(addr) >> 3) ^ ((word)(addr) >> (3+(log_size)))) \
38 & ((size) - 1))
39#define HASH2(addr,log_size) HASH3(addr, 1 << log_size, log_size)
40
41struct hash_chain_entry {
42 word hidden_key;
43 struct hash_chain_entry * next;
44};
45
46unsigned GC_finalization_failures = 0;
47 /* Number of finalization requests that failed for lack of memory. */
48
49static struct disappearing_link {
50 struct hash_chain_entry prolog;
51# define dl_hidden_link prolog.hidden_key
52 /* Field to be cleared. */
53# define dl_next(x) (struct disappearing_link *)((x) -> prolog.next)
54# define dl_set_next(x,y) (x) -> prolog.next = (struct hash_chain_entry *)(y)
55
56 word dl_hidden_obj; /* Pointer to object base */
57} **dl_head = 0;
58
59static signed_word log_dl_table_size = -1;
60 /* Binary log of */
61 /* current size of array pointed to by dl_head. */
62 /* -1 ==> size is 0. */
63
64word GC_dl_entries = 0; /* Number of entries currently in disappearing */
65 /* link table. */
66
67static struct finalizable_object {
68 struct hash_chain_entry prolog;
69# define fo_hidden_base prolog.hidden_key
70 /* Pointer to object base. */
71 /* No longer hidden once object */
72 /* is on finalize_now queue. */
73# define fo_next(x) (struct finalizable_object *)((x) -> prolog.next)
74# define fo_set_next(x,y) (x) -> prolog.next = (struct hash_chain_entry *)(y)
75 GC_finalization_proc fo_fn; /* Finalizer. */
76 ptr_t fo_client_data;
77 word fo_object_size; /* In bytes. */
78 finalization_mark_proc * fo_mark_proc; /* Mark-through procedure */
79} **fo_head = 0;
80
81struct finalizable_object * GC_finalize_now = 0;
82 /* LIst of objects that should be finalized now. */
83
84static signed_word log_fo_table_size = -1;
85
86word GC_fo_entries = 0;
87
88void GC_push_finalizer_structures GC_PROTO((void))
89{
90 GC_push_all((ptr_t)(&dl_head), (ptr_t)(&dl_head) + sizeof(word));
91 GC_push_all((ptr_t)(&fo_head), (ptr_t)(&fo_head) + sizeof(word));
92 GC_push_all((ptr_t)(&GC_finalize_now),
93 (ptr_t)(&GC_finalize_now) + sizeof(word));
94}
95
96/* Double the size of a hash table. *size_ptr is the log of its current */
97/* size. May be a noop. */
98/* *table is a pointer to an array of hash headers. If we succeed, we */
99/* update both *table and *log_size_ptr. */
100/* Lock is held. Signals are disabled. */
101void GC_grow_table(table, log_size_ptr)
102struct hash_chain_entry ***table;
103signed_word * log_size_ptr;
104{
105 register word i;
106 register struct hash_chain_entry *p;
107 int log_old_size = *log_size_ptr;
108 register int log_new_size = log_old_size + 1;
109 word old_size = ((log_old_size == -1)? 0: (1 << log_old_size));
110 register word new_size = 1 << log_new_size;
111 struct hash_chain_entry **new_table = (struct hash_chain_entry **)
112 GC_INTERNAL_MALLOC_IGNORE_OFF_PAGE(
113 (size_t)new_size * sizeof(struct hash_chain_entry *), NORMAL);
114
115 if (new_table == 0) {
116 if (table == 0) {
117 ABORT("Insufficient space for initial table allocation");
118 } else {
119 return;
120 }
121 }
122 for (i = 0; i < old_size; i++) {
123 p = (*table)[i];
124 while (p != 0) {
125 register ptr_t real_key = (ptr_t)REVEAL_POINTER(p -> hidden_key);
126 register struct hash_chain_entry *next = p -> next;
127 register int new_hash = HASH3(real_key, new_size, log_new_size);
128
129 p -> next = new_table[new_hash];
130 new_table[new_hash] = p;
131 p = next;
132 }
133 }
134 *log_size_ptr = log_new_size;
135 *table = new_table;
136}
137
138# if defined(__STDC__) || defined(__cplusplus)
139 int GC_register_disappearing_link(GC_PTR * link)
140# else
141 int GC_register_disappearing_link(link)
142 GC_PTR * link;
143# endif
144{
145 ptr_t base;
146
147 base = (ptr_t)GC_base((GC_PTR)link);
148 if (base == 0)
149 ABORT("Bad arg to GC_register_disappearing_link");
150 return(GC_general_register_disappearing_link(link, base));
151}
152
153# if defined(__STDC__) || defined(__cplusplus)
154 int GC_general_register_disappearing_link(GC_PTR * link,
155 GC_PTR obj)
156# else
157 int GC_general_register_disappearing_link(link, obj)
158 GC_PTR * link;
159 GC_PTR obj;
160# endif
161
162{
163 struct disappearing_link *curr_dl;
164 int index;
165 struct disappearing_link * new_dl;
166 DCL_LOCK_STATE;
167
168 if ((word)link & (ALIGNMENT-1))
169 ABORT("Bad arg to GC_general_register_disappearing_link");
170# ifdef THREADS
171 DISABLE_SIGNALS();
172 LOCK();
173# endif
174 if (log_dl_table_size == -1
175 || GC_dl_entries > ((word)1 << log_dl_table_size)) {
176# ifndef THREADS
177 DISABLE_SIGNALS();
178# endif
179 GC_grow_table((struct hash_chain_entry ***)(&dl_head),
180 &log_dl_table_size);
181# ifdef CONDPRINT
182 if (GC_print_stats) {
183 GC_printf1("Grew dl table to %lu entries\n",
184 (unsigned long)(1 << log_dl_table_size));
185 }
186# endif
187# ifndef THREADS
188 ENABLE_SIGNALS();
189# endif
190 }
191 index = HASH2(link, log_dl_table_size);
192 curr_dl = dl_head[index];
193 for (curr_dl = dl_head[index]; curr_dl != 0; curr_dl = dl_next(curr_dl)) {
194 if (curr_dl -> dl_hidden_link == HIDE_POINTER(link)) {
195 curr_dl -> dl_hidden_obj = HIDE_POINTER(obj);
196# ifdef THREADS
197 UNLOCK();
198 ENABLE_SIGNALS();
199# endif
200 return(1);
201 }
202 }
203 new_dl = (struct disappearing_link *)
204 GC_INTERNAL_MALLOC(sizeof(struct disappearing_link),NORMAL);
205 if (0 == new_dl) {
206# ifdef THREADS
207 UNLOCK();
208 ENABLE_SIGNALS();
209# endif
210 new_dl = (struct disappearing_link *)
211 GC_oom_fn(sizeof(struct disappearing_link));
212 if (0 == new_dl) {
213 GC_finalization_failures++;
214 return(0);
215 }
216 /* It's not likely we'll make it here, but ... */
217# ifdef THREADS
218 DISABLE_SIGNALS();
219 LOCK();
220# endif
221 }
222 new_dl -> dl_hidden_obj = HIDE_POINTER(obj);
223 new_dl -> dl_hidden_link = HIDE_POINTER(link);
224 dl_set_next(new_dl, dl_head[index]);
225 dl_head[index] = new_dl;
226 GC_dl_entries++;
227# ifdef THREADS
228 UNLOCK();
229 ENABLE_SIGNALS();
230# endif
231 return(0);
232}
233
234# if defined(__STDC__) || defined(__cplusplus)
235 int GC_unregister_disappearing_link(GC_PTR * link)
236# else
237 int GC_unregister_disappearing_link(link)
238 GC_PTR * link;
239# endif
240{
241 struct disappearing_link *curr_dl, *prev_dl;
242 int index;
243 DCL_LOCK_STATE;
244
245 DISABLE_SIGNALS();
246 LOCK();
247 index = HASH2(link, log_dl_table_size);
248 if (((unsigned long)link & (ALIGNMENT-1))) goto out;
249 prev_dl = 0; curr_dl = dl_head[index];
250 while (curr_dl != 0) {
251 if (curr_dl -> dl_hidden_link == HIDE_POINTER(link)) {
252 if (prev_dl == 0) {
253 dl_head[index] = dl_next(curr_dl);
254 } else {
255 dl_set_next(prev_dl, dl_next(curr_dl));
256 }
257 GC_dl_entries--;
258 UNLOCK();
259 ENABLE_SIGNALS();
260# ifdef DBG_HDRS_ALL
261 dl_set_next(curr_dl, 0);
262# else
263 GC_free((GC_PTR)curr_dl);
264# endif
265 return(1);
266 }
267 prev_dl = curr_dl;
268 curr_dl = dl_next(curr_dl);
269 }
270out:
271 UNLOCK();
272 ENABLE_SIGNALS();
273 return(0);
274}
275
276/* Possible finalization_marker procedures. Note that mark stack */
277/* overflow is handled by the caller, and is not a disaster. */
278GC_API void GC_normal_finalize_mark_proc(p)
279ptr_t p;
280{
281 hdr * hhdr = HDR(p);
282
283 PUSH_OBJ((word *)p, hhdr, GC_mark_stack_top,
284 &(GC_mark_stack[GC_mark_stack_size]));
285}
286
287/* This only pays very partial attention to the mark descriptor. */
288/* It does the right thing for normal and atomic objects, and treats */
289/* most others as normal. */
290GC_API void GC_ignore_self_finalize_mark_proc(p)
291ptr_t p;
292{
293 hdr * hhdr = HDR(p);
294 word descr = hhdr -> hb_descr;
295 ptr_t q, r;
296 ptr_t scan_limit;
297 ptr_t target_limit = p + WORDS_TO_BYTES(hhdr -> hb_sz) - 1;
298
299 if ((descr & GC_DS_TAGS) == GC_DS_LENGTH) {
300 scan_limit = p + descr - sizeof(word);
301 } else {
302 scan_limit = target_limit + 1 - sizeof(word);
303 }
304 for (q = p; q <= scan_limit; q += ALIGNMENT) {
305 r = *(ptr_t *)q;
306 if (r < p || r > target_limit) {
307 GC_PUSH_ONE_HEAP((word)r, q);
308 }
309 }
310}
311
312/*ARGSUSED*/
313GC_API void GC_null_finalize_mark_proc(p)
314ptr_t p;
315{
316}
317
318
319
320/* Register a finalization function. See gc.h for details. */
321/* in the nonthreads case, we try to avoid disabling signals, */
322/* since it can be expensive. Threads packages typically */
323/* make it cheaper. */
324/* The last parameter is a procedure that determines */
325/* marking for finalization ordering. Any objects marked */
326/* by that procedure will be guaranteed to not have been */
327/* finalized when this finalizer is invoked. */
328GC_API void GC_register_finalizer_inner(obj, fn, cd, ofn, ocd, mp)
329GC_PTR obj;
330GC_finalization_proc fn;
331GC_PTR cd;
332GC_finalization_proc * ofn;
333GC_PTR * ocd;
334finalization_mark_proc * mp;
335{
336 ptr_t base;
337 struct finalizable_object * curr_fo, * prev_fo;
338 int index;
339 struct finalizable_object *new_fo;
340 hdr *hhdr;
341 DCL_LOCK_STATE;
342
343# ifdef THREADS
344 DISABLE_SIGNALS();
345 LOCK();
346# endif
347 if (log_fo_table_size == -1
348 || GC_fo_entries > ((word)1 << log_fo_table_size)) {
349# ifndef THREADS
350 DISABLE_SIGNALS();
351# endif
352 GC_grow_table((struct hash_chain_entry ***)(&fo_head),
353 &log_fo_table_size);
354# ifdef CONDPRINT
355 if (GC_print_stats) {
356 GC_printf1("Grew fo table to %lu entries\n",
357 (unsigned long)(1 << log_fo_table_size));
358 }
359# endif
360# ifndef THREADS
361 ENABLE_SIGNALS();
362# endif
363 }
364 /* in the THREADS case signals are disabled and we hold allocation */
365 /* lock; otherwise neither is true. Proceed carefully. */
366 base = (ptr_t)obj;
367 index = HASH2(base, log_fo_table_size);
368 prev_fo = 0; curr_fo = fo_head[index];
369 while (curr_fo != 0) {
370 if (curr_fo -> fo_hidden_base == HIDE_POINTER(base)) {
371 /* Interruption by a signal in the middle of this */
372 /* should be safe. The client may see only *ocd */
373 /* updated, but we'll declare that to be his */
374 /* problem. */
375 if (ocd) *ocd = (GC_PTR) curr_fo -> fo_client_data;
376 if (ofn) *ofn = curr_fo -> fo_fn;
377 /* Delete the structure for base. */
378 if (prev_fo == 0) {
379 fo_head[index] = fo_next(curr_fo);
380 } else {
381 fo_set_next(prev_fo, fo_next(curr_fo));
382 }
383 if (fn == 0) {
384 GC_fo_entries--;
385 /* May not happen if we get a signal. But a high */
386 /* estimate will only make the table larger than */
387 /* necessary. */
388# if !defined(THREADS) && !defined(DBG_HDRS_ALL)
389 GC_free((GC_PTR)curr_fo);
390# endif
391 } else {
392 curr_fo -> fo_fn = fn;
393 curr_fo -> fo_client_data = (ptr_t)cd;
394 curr_fo -> fo_mark_proc = mp;
395 /* Reinsert it. We deleted it first to maintain */
396 /* consistency in the event of a signal. */
397 if (prev_fo == 0) {
398 fo_head[index] = curr_fo;
399 } else {
400 fo_set_next(prev_fo, curr_fo);
401 }
402 }
403# ifdef THREADS
404 UNLOCK();
405 ENABLE_SIGNALS();
406# endif
407 return;
408 }
409 prev_fo = curr_fo;
410 curr_fo = fo_next(curr_fo);
411 }
412 if (ofn) *ofn = 0;
413 if (ocd) *ocd = 0;
414 if (fn == 0) {
415# ifdef THREADS
416 UNLOCK();
417 ENABLE_SIGNALS();
418# endif
419 return;
420 }
421 GET_HDR(base, hhdr);
422 if (0 == hhdr) {
423 /* We won't collect it, hence finalizer wouldn't be run. */
424# ifdef THREADS
425 UNLOCK();
426 ENABLE_SIGNALS();
427# endif
428 return;
429 }
430 new_fo = (struct finalizable_object *)
431 GC_INTERNAL_MALLOC(sizeof(struct finalizable_object),NORMAL);
432 if (0 == new_fo) {
433# ifdef THREADS
434 UNLOCK();
435 ENABLE_SIGNALS();
436# endif
437 new_fo = (struct finalizable_object *)
438 GC_oom_fn(sizeof(struct finalizable_object));
439 if (0 == new_fo) {
440 GC_finalization_failures++;
441 return;
442 }
443 /* It's not likely we'll make it here, but ... */
444# ifdef THREADS
445 DISABLE_SIGNALS();
446 LOCK();
447# endif
448 }
449 new_fo -> fo_hidden_base = (word)HIDE_POINTER(base);
450 new_fo -> fo_fn = fn;
451 new_fo -> fo_client_data = (ptr_t)cd;
452 new_fo -> fo_object_size = hhdr -> hb_sz;
453 new_fo -> fo_mark_proc = mp;
454 fo_set_next(new_fo, fo_head[index]);
455 GC_fo_entries++;
456 fo_head[index] = new_fo;
457# ifdef THREADS
458 UNLOCK();
459 ENABLE_SIGNALS();
460# endif
461}
462
463# if defined(__STDC__)
464 void GC_register_finalizer(void * obj,
465 GC_finalization_proc fn, void * cd,
466 GC_finalization_proc *ofn, void ** ocd)
467# else
468 void GC_register_finalizer(obj, fn, cd, ofn, ocd)
469 GC_PTR obj;
470 GC_finalization_proc fn;
471 GC_PTR cd;
472 GC_finalization_proc * ofn;
473 GC_PTR * ocd;
474# endif
475{
476 GC_register_finalizer_inner(obj, fn, cd, ofn,
477 ocd, GC_normal_finalize_mark_proc);
478}
479
480# if defined(__STDC__)
481 void GC_register_finalizer_ignore_self(void * obj,
482 GC_finalization_proc fn, void * cd,
483 GC_finalization_proc *ofn, void ** ocd)
484# else
485 void GC_register_finalizer_ignore_self(obj, fn, cd, ofn, ocd)
486 GC_PTR obj;
487 GC_finalization_proc fn;
488 GC_PTR cd;
489 GC_finalization_proc * ofn;
490 GC_PTR * ocd;
491# endif
492{
493 GC_register_finalizer_inner(obj, fn, cd, ofn,
494 ocd, GC_ignore_self_finalize_mark_proc);
495}
496
497# if defined(__STDC__)
498 void GC_register_finalizer_no_order(void * obj,
499 GC_finalization_proc fn, void * cd,
500 GC_finalization_proc *ofn, void ** ocd)
501# else
502 void GC_register_finalizer_no_order(obj, fn, cd, ofn, ocd)
503 GC_PTR obj;
504 GC_finalization_proc fn;
505 GC_PTR cd;
506 GC_finalization_proc * ofn;
507 GC_PTR * ocd;
508# endif
509{
510 GC_register_finalizer_inner(obj, fn, cd, ofn,
511 ocd, GC_null_finalize_mark_proc);
512}
513
514#ifndef NO_DEBUGGING
515void GC_dump_finalization()
516{
517 struct disappearing_link * curr_dl;
518 struct finalizable_object * curr_fo;
519 ptr_t real_ptr, real_link;
520 int dl_size = (log_dl_table_size == -1 ) ? 0 : (1 << log_dl_table_size);
521 int fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
522 int i;
523
524 GC_printf0("Disappearing links:\n");
525 for (i = 0; i < dl_size; i++) {
526 for (curr_dl = dl_head[i]; curr_dl != 0; curr_dl = dl_next(curr_dl)) {
527 real_ptr = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_obj);
528 real_link = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_link);
529 GC_printf2("Object: 0x%lx, Link:0x%lx\n", real_ptr, real_link);
530 }
531 }
532 GC_printf0("Finalizers:\n");
533 for (i = 0; i < fo_size; i++) {
534 for (curr_fo = fo_head[i]; curr_fo != 0; curr_fo = fo_next(curr_fo)) {
535 real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
536 GC_printf1("Finalizable object: 0x%lx\n", real_ptr);
537 }
538 }
539}
540#endif
541
542/* Called with world stopped. Cause disappearing links to disappear, */
543/* and invoke finalizers. */
544void GC_finalize()
545{
546 struct disappearing_link * curr_dl, * prev_dl, * next_dl;
547 struct finalizable_object * curr_fo, * prev_fo, * next_fo;
548 ptr_t real_ptr, real_link;
549 register int i;
550 int dl_size = (log_dl_table_size == -1 ) ? 0 : (1 << log_dl_table_size);
551 int fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
552
553 /* Make disappearing links disappear */
554 for (i = 0; i < dl_size; i++) {
555 curr_dl = dl_head[i];
556 prev_dl = 0;
557 while (curr_dl != 0) {
558 real_ptr = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_obj);
559 real_link = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_link);
560 if (!GC_is_marked(real_ptr)) {
561 *(word *)real_link = 0;
562 next_dl = dl_next(curr_dl);
563 if (prev_dl == 0) {
564 dl_head[i] = next_dl;
565 } else {
566 dl_set_next(prev_dl, next_dl);
567 }
568 GC_clear_mark_bit((ptr_t)curr_dl);
569 GC_dl_entries--;
570 curr_dl = next_dl;
571 } else {
572 prev_dl = curr_dl;
573 curr_dl = dl_next(curr_dl);
574 }
575 }
576 }
577 /* Mark all objects reachable via chains of 1 or more pointers */
578 /* from finalizable objects. */
579 GC_ASSERT(GC_mark_state == MS_NONE);
580 for (i = 0; i < fo_size; i++) {
581 for (curr_fo = fo_head[i]; curr_fo != 0; curr_fo = fo_next(curr_fo)) {
582 real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
583 if (!GC_is_marked(real_ptr)) {
584 GC_MARKED_FOR_FINALIZATION(real_ptr);
585 GC_MARK_FO(real_ptr, curr_fo -> fo_mark_proc);
586 if (GC_is_marked(real_ptr)) {
587 WARN("Finalization cycle involving %lx\n", real_ptr);
588 }
589 }
590 }
591 }
592 /* Enqueue for finalization all objects that are still */
593 /* unreachable. */
594 GC_words_finalized = 0;
595 for (i = 0; i < fo_size; i++) {
596 curr_fo = fo_head[i];
597 prev_fo = 0;
598 while (curr_fo != 0) {
599 real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
600 if (!GC_is_marked(real_ptr)) {
601 if (!GC_java_finalization) {
602 GC_set_mark_bit(real_ptr);
603 }
604 /* Delete from hash table */
605 next_fo = fo_next(curr_fo);
606 if (prev_fo == 0) {
607 fo_head[i] = next_fo;
608 } else {
609 fo_set_next(prev_fo, next_fo);
610 }
611 GC_fo_entries--;
612 /* Add to list of objects awaiting finalization. */
613 fo_set_next(curr_fo, GC_finalize_now);
614 GC_finalize_now = curr_fo;
615 /* unhide object pointer so any future collections will */
616 /* see it. */
617 curr_fo -> fo_hidden_base =
618 (word) REVEAL_POINTER(curr_fo -> fo_hidden_base);
619 GC_words_finalized +=
620 ALIGNED_WORDS(curr_fo -> fo_object_size)
621 + ALIGNED_WORDS(sizeof(struct finalizable_object));
622 GC_ASSERT(GC_is_marked(GC_base((ptr_t)curr_fo)));
623 curr_fo = next_fo;
624 } else {
625 prev_fo = curr_fo;
626 curr_fo = fo_next(curr_fo);
627 }
628 }
629 }
630
631 if (GC_java_finalization) {
632 /* make sure we mark everything reachable from objects finalized
633 using the no_order mark_proc */
634 for (curr_fo = GC_finalize_now;
635 curr_fo != NULL; curr_fo = fo_next(curr_fo)) {
636 real_ptr = (ptr_t)curr_fo -> fo_hidden_base;
637 if (!GC_is_marked(real_ptr)) {
638 if (curr_fo -> fo_mark_proc == GC_null_finalize_mark_proc) {
639 GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
640 }
641 GC_set_mark_bit(real_ptr);
642 }
643 }
644 }
645
646 /* Remove dangling disappearing links. */
647 for (i = 0; i < dl_size; i++) {
648 curr_dl = dl_head[i];
649 prev_dl = 0;
650 while (curr_dl != 0) {
651 real_link = GC_base((ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_link));
652 if (real_link != 0 && !GC_is_marked(real_link)) {
653 next_dl = dl_next(curr_dl);
654 if (prev_dl == 0) {
655 dl_head[i] = next_dl;
656 } else {
657 dl_set_next(prev_dl, next_dl);
658 }
659 GC_clear_mark_bit((ptr_t)curr_dl);
660 GC_dl_entries--;
661 curr_dl = next_dl;
662 } else {
663 prev_dl = curr_dl;
664 curr_dl = dl_next(curr_dl);
665 }
666 }
667 }
668}
669
670#ifndef JAVA_FINALIZATION_NOT_NEEDED
671
672/* Enqueue all remaining finalizers to be run - Assumes lock is
673 * held, and signals are disabled */
674void GC_enqueue_all_finalizers()
675{
676 struct finalizable_object * curr_fo, * prev_fo, * next_fo;
677 ptr_t real_ptr;
678 register int i;
679 int fo_size;
680
681 fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
682 GC_words_finalized = 0;
683 for (i = 0; i < fo_size; i++) {
684 curr_fo = fo_head[i];
685 prev_fo = 0;
686 while (curr_fo != 0) {
687 real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
688 GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
689 GC_set_mark_bit(real_ptr);
690
691 /* Delete from hash table */
692 next_fo = fo_next(curr_fo);
693 if (prev_fo == 0) {
694 fo_head[i] = next_fo;
695 } else {
696 fo_set_next(prev_fo, next_fo);
697 }
698 GC_fo_entries--;
699
700 /* Add to list of objects awaiting finalization. */
701 fo_set_next(curr_fo, GC_finalize_now);
702 GC_finalize_now = curr_fo;
703
704 /* unhide object pointer so any future collections will */
705 /* see it. */
706 curr_fo -> fo_hidden_base =
707 (word) REVEAL_POINTER(curr_fo -> fo_hidden_base);
708
709 GC_words_finalized +=
710 ALIGNED_WORDS(curr_fo -> fo_object_size)
711 + ALIGNED_WORDS(sizeof(struct finalizable_object));
712 curr_fo = next_fo;
713 }
714 }
715
716 return;
717}
718
719/* Invoke all remaining finalizers that haven't yet been run.
720 * This is needed for strict compliance with the Java standard,
721 * which can make the runtime guarantee that all finalizers are run.
722 * Unfortunately, the Java standard implies we have to keep running
723 * finalizers until there are no more left, a potential infinite loop.
724 * YUCK.
725 * Note that this is even more dangerous than the usual Java
726 * finalizers, in that objects reachable from static variables
727 * may have been finalized when these finalizers are run.
728 * Finalizers run at this point must be prepared to deal with a
729 * mostly broken world.
730 * This routine is externally callable, so is called without
731 * the allocation lock.
732 */
733GC_API void GC_finalize_all()
734{
735 DCL_LOCK_STATE;
736
737 DISABLE_SIGNALS();
738 LOCK();
739 while (GC_fo_entries > 0) {
740 GC_enqueue_all_finalizers();
741 UNLOCK();
742 ENABLE_SIGNALS();
743 GC_INVOKE_FINALIZERS();
744 DISABLE_SIGNALS();
745 LOCK();
746 }
747 UNLOCK();
748 ENABLE_SIGNALS();
749}
750#endif
751
752/* Returns true if it is worth calling GC_invoke_finalizers. (Useful if */
753/* finalizers can only be called from some kind of `safe state' and */
754/* getting into that safe state is expensive.) */
755int GC_should_invoke_finalizers GC_PROTO((void))
756{
757 return GC_finalize_now != 0;
758}
759
760/* Invoke finalizers for all objects that are ready to be finalized. */
761/* Should be called without allocation lock. */
762int GC_invoke_finalizers()
763{
764 struct finalizable_object * curr_fo;
765 int count = 0;
766 word mem_freed_before;
767 DCL_LOCK_STATE;
768
769 while (GC_finalize_now != 0) {
770# ifdef THREADS
771 DISABLE_SIGNALS();
772 LOCK();
773# endif
774 if (count == 0) {
775 mem_freed_before = GC_mem_freed;
776 }
777 curr_fo = GC_finalize_now;
778# ifdef THREADS
779 if (curr_fo != 0) GC_finalize_now = fo_next(curr_fo);
780 UNLOCK();
781 ENABLE_SIGNALS();
782 if (curr_fo == 0) break;
783# else
784 GC_finalize_now = fo_next(curr_fo);
785# endif
786 fo_set_next(curr_fo, 0);
787 (*(curr_fo -> fo_fn))((ptr_t)(curr_fo -> fo_hidden_base),
788 curr_fo -> fo_client_data);
789 curr_fo -> fo_client_data = 0;
790 ++count;
791# ifdef UNDEFINED
792 /* This is probably a bad idea. It throws off accounting if */
793 /* nearly all objects are finalizable. O.w. it shouldn't */
794 /* matter. */
795 GC_free((GC_PTR)curr_fo);
796# endif
797 }
798 if (count != 0 && mem_freed_before != GC_mem_freed) {
799 LOCK();
800 GC_finalizer_mem_freed += (GC_mem_freed - mem_freed_before);
801 UNLOCK();
802 }
803 return count;
804}
805
806void (* GC_finalizer_notifier)() = (void (*) GC_PROTO((void)))0;
807
808static GC_word last_finalizer_notification = 0;
809
810void GC_notify_or_invoke_finalizers GC_PROTO((void))
811{
812 /* This is a convenient place to generate backtraces if appropriate, */
813 /* since that code is not callable with the allocation lock. */
814# if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
815 static word last_back_trace_gc_no = 1; /* Skip first one. */
816
817 if (GC_gc_no > last_back_trace_gc_no) {
818 word i;
819
820# ifdef KEEP_BACK_PTRS
821 LOCK();
822 /* Stops when GC_gc_no wraps; that's OK. */
823 last_back_trace_gc_no = (word)(-1); /* disable others. */
824 for (i = 0; i < GC_backtraces; ++i) {
825 /* FIXME: This tolerates concurrent heap mutation, */
826 /* which may cause occasional mysterious results. */
827 /* We need to release the GC lock, since GC_print_callers */
828 /* acquires it. It probably shouldn't. */
829 UNLOCK();
830 GC_generate_random_backtrace_no_gc();
831 LOCK();
832 }
833 last_back_trace_gc_no = GC_gc_no;
834 UNLOCK();
835# endif
836# ifdef MAKE_BACK_GRAPH
837 if (GC_print_back_height)
838 GC_print_back_graph_stats();
839# endif
840 }
841# endif
842 if (GC_finalize_now == 0) return;
843 if (!GC_finalize_on_demand) {
844 (void) GC_invoke_finalizers();
845# ifndef THREADS
846 GC_ASSERT(GC_finalize_now == 0);
847# endif /* Otherwise GC can run concurrently and add more */
848 return;
849 }
850 if (GC_finalizer_notifier != (void (*) GC_PROTO((void)))0
851 && last_finalizer_notification != GC_gc_no) {
852 last_finalizer_notification = GC_gc_no;
853 GC_finalizer_notifier();
854 }
855}
856
857# ifdef __STDC__
858 GC_PTR GC_call_with_alloc_lock(GC_fn_type fn,
859 GC_PTR client_data)
860# else
861 GC_PTR GC_call_with_alloc_lock(fn, client_data)
862 GC_fn_type fn;
863 GC_PTR client_data;
864# endif
865{
866 GC_PTR result;
867 DCL_LOCK_STATE;
868
869# ifdef THREADS
870 DISABLE_SIGNALS();
871 LOCK();
872 SET_LOCK_HOLDER();
873# endif
874 result = (*fn)(client_data);
875# ifdef THREADS
876# ifndef GC_ASSERTIONS
877 UNSET_LOCK_HOLDER();
878# endif /* o.w. UNLOCK() does it implicitly */
879 UNLOCK();
880 ENABLE_SIGNALS();
881# endif
882 return(result);
883}
884
885#if !defined(NO_DEBUGGING)
886
887void GC_print_finalization_stats()
888{
889 struct finalizable_object *fo = GC_finalize_now;
890 size_t ready = 0;
891
892 GC_printf2("%lu finalization table entries; %lu disappearing links\n",
893 GC_fo_entries, GC_dl_entries);
894 for (; 0 != fo; fo = fo_next(fo)) ++ready;
895 GC_printf1("%lu objects are eligible for immediate finalization\n", ready);
896}
897
898#endif /* NO_DEBUGGING */
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