2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
5 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
6 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
8 * Permission is hereby granted to use or copy this program
9 * for any purpose, provided the above notices are retained on all copies.
10 * Permission to modify the code and to distribute modified code is granted,
11 * provided the above notices are retained, and a notice that the code was
12 * modified is included with the above copyright notice.
14 /* Boehm, July 31, 1995 5:02 pm PDT */
20 #define I_HIDE_POINTERS /* To make GC_call_with_alloc_lock visible */
23 #ifdef SOLARIS_THREADS
24 # include <sys/syscall.h>
32 # include "il/PCR_IL.h"
33 PCR_Th_ML GC_allocate_ml;
36 /* Critical section counter is defined in the M3 runtime */
37 /* That's all we use. */
39 # ifdef SOLARIS_THREADS
40 mutex_t GC_allocate_ml; /* Implicitly initialized. */
43 GC_API CRITICAL_SECTION GC_allocate_ml;
45 # if defined(IRIX_THREADS) || defined(LINUX_THREADS)
47 pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
49 pthread_t GC_lock_holder = NO_THREAD;
51 --> declare allocator lock here
59 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
62 GC_bool GC_debugging_started = FALSE;
63 /* defined here so we don't have to load debug_malloc.o */
65 void (*GC_check_heap)() = (void (*)())0;
67 void (*GC_start_call_back)() = (void (*)())0;
69 ptr_t GC_stackbottom = 0;
71 GC_bool GC_dont_gc = 0;
76 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
81 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
83 extern signed_word GC_mem_found;
86 /* Set things up so that GC_size_map[i] >= words(i), */
87 /* but not too much bigger */
88 /* and so that size_map contains relatively few distinct entries */
89 /* This is stolen from Russ Atkinson's Cedar quantization */
90 /* alogrithm (but we precompute it). */
93 void GC_init_size_map()
97 /* Map size 0 to 1. This avoids problems at lower levels. */
99 /* One word objects don't have to be 2 word aligned. */
100 for (i = 1; i < sizeof(word); i++) {
103 GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
104 for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
106 GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
108 GC_size_map[i] = ROUNDED_UP_WORDS(i);
111 for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
112 GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
114 /* We leave the rest of the array to be filled in on demand. */
117 /* Fill in additional entries in GC_size_map, including the ith one */
118 /* We assume the ith entry is currently 0. */
119 /* Note that a filled in section of the array ending at n always */
120 /* has length at least n/4. */
121 void GC_extend_size_map(i)
124 word orig_word_sz = ROUNDED_UP_WORDS(i);
125 word word_sz = orig_word_sz;
126 register word byte_sz = WORDS_TO_BYTES(word_sz);
127 /* The size we try to preserve. */
128 /* Close to to i, unless this would */
129 /* introduce too many distinct sizes. */
130 word smaller_than_i = byte_sz - (byte_sz >> 3);
131 word much_smaller_than_i = byte_sz - (byte_sz >> 2);
132 register word low_limit; /* The lowest indexed entry we */
136 if (GC_size_map[smaller_than_i] == 0) {
137 low_limit = much_smaller_than_i;
138 while (GC_size_map[low_limit] != 0) low_limit++;
140 low_limit = smaller_than_i + 1;
141 while (GC_size_map[low_limit] != 0) low_limit++;
142 word_sz = ROUNDED_UP_WORDS(low_limit);
143 word_sz += word_sz >> 3;
144 if (word_sz < orig_word_sz) word_sz = orig_word_sz;
150 if (word_sz > MAXOBJSZ) {
153 /* If we can fit the same number of larger objects in a block, */
156 size_t number_of_objs = BODY_SZ/word_sz;
157 word_sz = BODY_SZ/number_of_objs;
162 byte_sz = WORDS_TO_BYTES(word_sz);
163 # ifdef ADD_BYTE_AT_END
164 /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
168 for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
174 * The following is a gross hack to deal with a problem that can occur
175 * on machines that are sloppy about stack frame sizes, notably SPARC.
176 * Bogus pointers may be written to the stack and not cleared for
177 * a LONG time, because they always fall into holes in stack frames
178 * that are not written. We partially address this by clearing
179 * sections of the stack whenever we get control.
181 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
183 # define CLEAR_SIZE 2048
185 # define CLEAR_SIZE 213
187 # define DEGRADE_RATE 50
189 word GC_min_sp; /* Coolest stack pointer value from which we've */
190 /* already cleared the stack. */
192 # ifdef STACK_GROWS_DOWN
193 # define COOLER_THAN >
194 # define HOTTER_THAN <
195 # define MAKE_COOLER(x,y) if ((word)(x)+(y) > (word)(x)) {(x) += (y);} \
196 else {(x) = (word)ONES;}
197 # define MAKE_HOTTER(x,y) (x) -= (y)
199 # define COOLER_THAN <
200 # define HOTTER_THAN >
201 # define MAKE_COOLER(x,y) if ((word)(x)-(y) < (word)(x)) {(x) -= (y);} else {(x) = 0;}
202 # define MAKE_HOTTER(x,y) (x) += (y)
206 /* "hottest" stack pointer value we have seen */
207 /* recently. Degrades over time. */
209 word GC_words_allocd_at_reset;
211 #if defined(ASM_CLEAR_CODE) && !defined(THREADS)
212 extern ptr_t GC_clear_stack_inner();
215 #if !defined(ASM_CLEAR_CODE) && !defined(THREADS)
216 /* Clear the stack up to about limit. Return arg. */
218 ptr_t GC_clear_stack_inner(arg, limit)
222 word dummy[CLEAR_SIZE];
224 BZERO(dummy, CLEAR_SIZE*sizeof(word));
225 if ((word)(dummy) COOLER_THAN limit) {
226 (void) GC_clear_stack_inner(arg, limit);
228 /* Make sure the recursive call is not a tail call, and the bzero */
229 /* call is not recognized as dead code. */
230 GC_noop1((word)dummy);
235 /* Clear some of the inaccessible part of the stack. Returns its */
236 /* argument, so it can be used in a tail call position, hence clearing */
238 ptr_t GC_clear_stack(arg)
241 register word sp = (word)GC_approx_sp(); /* Hotter than actual sp */
243 word dummy[CLEAR_SIZE];
249 /* Extra bytes we clear every time. This clears our own */
250 /* activation record, and should cause more frequent */
251 /* clearing near the cold end of the stack, a good thing. */
252 # define GC_SLOP 4000
253 /* We make GC_high_water this much hotter than we really saw */
254 /* saw it, to cover for GC noise etc. above our current frame. */
255 # define CLEAR_THRESHOLD 100000
256 /* We restart the clearing process after this many bytes of */
257 /* allocation. Otherwise very heavily recursive programs */
258 /* with sparse stacks may result in heaps that grow almost */
259 /* without bounds. As the heap gets larger, collection */
260 /* frequency decreases, thus clearing frequency would decrease, */
261 /* thus more junk remains accessible, thus the heap gets */
264 BZERO(dummy, CLEAR_SIZE*sizeof(word));
266 if (GC_gc_no > GC_stack_last_cleared) {
267 /* Start things over, so we clear the entire stack again */
268 if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
269 GC_min_sp = GC_high_water;
270 GC_stack_last_cleared = GC_gc_no;
271 GC_words_allocd_at_reset = GC_words_allocd;
273 /* Adjust GC_high_water */
274 MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
275 if (sp HOTTER_THAN GC_high_water) {
278 MAKE_HOTTER(GC_high_water, GC_SLOP);
280 MAKE_HOTTER(limit, SLOP);
281 if (sp COOLER_THAN limit) {
282 limit &= ~0xf; /* Make it sufficiently aligned for assembly */
283 /* implementations of GC_clear_stack_inner. */
285 return(GC_clear_stack_inner(arg, limit));
286 } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
288 /* Restart clearing process, but limit how much clearing we do. */
290 MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
291 if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
292 GC_words_allocd_at_reset = GC_words_allocd;
299 /* Return a pointer to the base address of p, given a pointer to a */
300 /* an address within an object. Return 0 o.w. */
302 GC_PTR GC_base(GC_PTR p)
309 register struct hblk *h;
310 register bottom_index *bi;
311 register hdr *candidate_hdr;
315 if (!GC_is_initialized) return 0;
318 candidate_hdr = HDR_FROM_BI(bi, r);
319 if (candidate_hdr == 0) return(0);
320 /* If it's a pointer to the middle of a large object, move it */
321 /* to the beginning. */
322 while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
323 h = FORWARDED_ADDR(h,candidate_hdr);
324 r = (word)h + HDR_BYTES;
325 candidate_hdr = HDR(h);
327 if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
328 /* Make sure r points to the beginning of the object */
329 r &= ~(WORDS_TO_BYTES(1) - 1);
331 register int offset = (char *)r - (char *)(HBLKPTR(r));
332 register signed_word sz = candidate_hdr -> hb_sz;
334 # ifdef ALL_INTERIOR_POINTERS
335 register map_entry_type map_entry;
337 map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
338 if (map_entry == OBJ_INVALID) {
341 r -= WORDS_TO_BYTES(map_entry);
342 limit = r + WORDS_TO_BYTES(sz);
344 register int correction;
346 offset = BYTES_TO_WORDS(offset - HDR_BYTES);
347 correction = offset % sz;
348 r -= (WORDS_TO_BYTES(correction));
349 limit = r + WORDS_TO_BYTES(sz);
350 if (limit > (word)(h + 1)
351 && sz <= BYTES_TO_WORDS(HBLKSIZE) - HDR_WORDS) {
355 if ((word)p >= limit) return(0);
361 /* Return the size of an object, given a pointer to its base. */
362 /* (For small obects this also happens to work from interior pointers, */
363 /* but that shouldn't be relied upon.) */
365 size_t GC_size(GC_PTR p)
372 register hdr * hhdr = HDR(p);
374 sz = WORDS_TO_BYTES(hhdr -> hb_sz);
382 size_t GC_get_heap_size GC_PROTO(())
384 return ((size_t) GC_heapsize);
387 size_t GC_get_bytes_since_gc GC_PROTO(())
389 return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
392 GC_bool GC_is_initialized = FALSE;
407 extern void GC_init_win32();
410 extern void GC_setpagesize();
418 if (GC_is_initialized) return;
420 GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
424 # if defined(LINUX) && defined(POWERPC)
427 # ifdef SOLARIS_THREADS
429 /* We need dirty bits in order to find live stack sections. */
432 # if defined(IRIX_THREADS) || defined(LINUX_THREADS)
435 # if !defined(THREADS) || defined(SOLARIS_THREADS) || defined(WIN32_THREADS) \
436 || defined(IRIX_THREADS) || defined(LINUX_THREADS)
437 if (GC_stackbottom == 0) {
438 GC_stackbottom = GC_get_stack_base();
441 if (sizeof (ptr_t) != sizeof(word)) {
442 ABORT("sizeof (ptr_t) != sizeof(word)\n");
444 if (sizeof (signed_word) != sizeof(word)) {
445 ABORT("sizeof (signed_word) != sizeof(word)\n");
447 if (sizeof (struct hblk) != HBLKSIZE) {
448 ABORT("sizeof (struct hblk) != HBLKSIZE\n");
451 # if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
453 "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
455 # if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
457 "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
459 # ifdef STACK_GROWS_DOWN
460 if ((word)(&dummy) > (word)GC_stackbottom) {
462 "STACK_GROWS_DOWN is defd, but stack appears to grow up\n");
463 # ifndef UTS4 /* Compiler bug workaround */
464 GC_err_printf2("sp = 0x%lx, GC_stackbottom = 0x%lx\n",
465 (unsigned long) (&dummy),
466 (unsigned long) GC_stackbottom);
468 ABORT("stack direction 3\n");
471 if ((word)(&dummy) < (word)GC_stackbottom) {
473 "STACK_GROWS_UP is defd, but stack appears to grow down\n");
474 GC_err_printf2("sp = 0x%lx, GC_stackbottom = 0x%lx\n",
475 (unsigned long) (&dummy),
476 (unsigned long) GC_stackbottom);
477 ABORT("stack direction 4");
481 # if !defined(_AUX_SOURCE) || defined(__GNUC__)
482 if ((word)(-1) < (word)0) {
483 GC_err_printf0("The type word should be an unsigned integer type\n");
484 GC_err_printf0("It appears to be signed\n");
488 if ((signed_word)(-1) >= (signed_word)0) {
490 "The type signed_word should be a signed integer type\n");
491 GC_err_printf0("It appears to be unsigned\n");
492 ABORT("signed_word");
495 /* Add initial guess of root sets. Do this first, since sbrk(0) */
497 GC_register_data_segments();
501 if (!GC_expand_hp_inner((word)MINHINCR)) {
502 GC_err_printf0("Can't start up: not enough memory\n");
505 /* Preallocate large object map. It's otherwise inconvenient to */
506 /* deal with failure. */
507 if (!GC_add_map_entry((word)0)) {
508 GC_err_printf0("Can't start up: not enough memory\n");
511 GC_register_displacement_inner(0L);
516 if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
518 ABORT("Can't lock load state\n");
519 } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
520 ABORT("Can't unlock load state\n");
525 /* Get black list set up */
527 # ifdef STUBBORN_ALLOC
530 GC_is_initialized = TRUE;
531 /* Convince lint that some things are used */
534 extern char * GC_copyright[];
535 extern int GC_read();
536 extern void GC_register_finalizer_no_order();
538 GC_noop(GC_copyright, GC_find_header,
539 GC_push_one, GC_call_with_alloc_lock, GC_read,
541 # ifndef NO_DEBUGGING
544 GC_register_finalizer_no_order);
549 void GC_enable_incremental GC_PROTO(())
556 if (GC_incremental) goto out;
560 extern GC_bool GC_is_win32s();
562 /* VirtualProtect is not functional under win32s. */
563 if (GC_is_win32s()) goto out;
565 # endif /* MSWIN32 */
566 # ifndef SOLARIS_THREADS
569 if (!GC_is_initialized) {
573 /* Can't easily do it. */
578 if (GC_words_allocd > 0) {
579 /* There may be unmarked reachable objects */
581 } /* else we're OK in assuming everything's */
582 /* clean since nothing can point to an */
583 /* unmarked object. */
585 GC_incremental = TRUE;
594 # define LOG_FILE "gc.log"
596 HANDLE GC_stdout = 0, GC_stderr;
603 GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
604 FILE_SHARE_READ | FILE_SHARE_WRITE,
605 NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
607 if (INVALID_HANDLE_VALUE == GC_stdout) ABORT("Open of log file failed");
609 if (GC_stderr == 0) {
610 GC_stderr = GC_stdout;
616 #if defined(OS2) || defined(MACOS)
617 FILE * GC_stdout = NULL;
618 FILE * GC_stderr = NULL;
619 int GC_tmp; /* Should really be local ... */
623 if (GC_stdout == NULL) {
626 if (GC_stderr == NULL) {
632 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32)
640 #if !defined(MSWIN32) && !defined(OS2) && !defined(MACOS)
641 int GC_write(fd, buf, len)
646 register int bytes_written = 0;
649 while (bytes_written < len) {
650 # ifdef SOLARIS_THREADS
651 result = syscall(SYS_write, fd, buf + bytes_written,
652 len - bytes_written);
654 result = write(fd, buf + bytes_written, len - bytes_written);
656 if (-1 == result) return(result);
657 bytes_written += result;
659 return(bytes_written);
664 # define WRITE(f, buf, len) (GC_set_files(), \
665 GC_tmp = WriteFile((f), (buf), \
666 (len), &GC_junk, NULL),\
669 # if defined(OS2) || defined(MACOS)
670 # define WRITE(f, buf, len) (GC_set_files(), \
671 GC_tmp = fwrite((buf), 1, (len), (f)), \
674 # define WRITE(f, buf, len) GC_write((f), (buf), (len))
678 /* A version of printf that is unlikely to call malloc, and is thus safer */
679 /* to call from the collector in case malloc has been bound to GC_malloc. */
680 /* Assumes that no more than 1023 characters are written at once. */
681 /* Assumes that all arguments have been converted to something of the */
682 /* same size as long, and that the format conversions expect something */
684 void GC_printf(format, a, b, c, d, e, f)
686 long a, b, c, d, e, f;
690 if (GC_quiet) return;
692 (void) sprintf(buf, format, a, b, c, d, e, f);
693 if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
694 if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
697 void GC_err_printf(format, a, b, c, d, e, f)
699 long a, b, c, d, e, f;
704 (void) sprintf(buf, format, a, b, c, d, e, f);
705 if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
706 if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
712 if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
715 # if defined(__STDC__) || defined(__cplusplus)
716 void GC_default_warn_proc(char *msg, GC_word arg)
718 void GC_default_warn_proc(msg, arg)
723 GC_err_printf1(msg, (unsigned long)arg);
726 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
728 # if defined(__STDC__) || defined(__cplusplus)
729 GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
731 GC_warn_proc GC_set_warn_proc(p)
738 result = GC_current_warn_proc;
739 GC_current_warn_proc = p;
749 GC_err_printf1("%s\n", msg);
756 void GC_print_callers (info)
757 struct callinfo info[NFRAMES];
762 GC_err_printf0("\tCaller at allocation:\n");
764 GC_err_printf0("\tCall chain at allocation:\n");
766 for (i = 0; i < NFRAMES; i++) {
767 if (info[i].ci_pc == 0) break;
769 GC_err_printf0("\t\targs: ");
770 for (j = 0; j < NARGS; j++) {
771 if (j != 0) GC_err_printf0(", ");
772 GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
773 ~(info[i].ci_arg[j]));
775 GC_err_printf0("\n");
777 GC_err_printf1("\t\t##PC##= 0x%X\n", info[i].ci_pc);
781 #endif /* SAVE_CALL_CHAIN */
795 #if !defined(NO_DEBUGGING)
799 GC_printf0("***Static roots:\n");
800 GC_print_static_roots();
801 GC_printf0("\n***Heap sections:\n");
802 GC_print_heap_sects();
803 GC_printf0("\n***Free blocks:\n");
804 GC_print_hblkfreelist();
805 GC_printf0("\n***Blocks in use:\n");
806 GC_print_block_list();
809 # endif /* NO_DEBUGGING */