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Diffstat (limited to 'gc/blacklst.c')
| -rw-r--r-- | gc/blacklst.c | 300 |
1 files changed, 0 insertions, 300 deletions
diff --git a/gc/blacklst.c b/gc/blacklst.c deleted file mode 100644 index ae2f95c..0000000 --- a/gc/blacklst.c +++ /dev/null @@ -1,300 +0,0 @@ -/* - * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers - * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. - * - * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED - * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. - * - * Permission is hereby granted to use or copy this program - * for any purpose, provided the above notices are retained on all copies. - * Permission to modify the code and to distribute modified code is granted, - * provided the above notices are retained, and a notice that the code was - * modified is included with the above copyright notice. - */ -/* Boehm, August 9, 1995 6:09 pm PDT */ -# include "private/gc_priv.h" - -/* - * We maintain several hash tables of hblks that have had false hits. - * Each contains one bit per hash bucket; If any page in the bucket - * has had a false hit, we assume that all of them have. - * See the definition of page_hash_table in gc_private.h. - * False hits from the stack(s) are much more dangerous than false hits - * from elsewhere, since the former can pin a large object that spans the - * block, eventhough it does not start on the dangerous block. - */ - -/* - * Externally callable routines are: - - * GC_add_to_black_list_normal - * GC_add_to_black_list_stack - * GC_promote_black_lists - * GC_is_black_listed - * - * All require that the allocator lock is held. - */ - -/* Pointers to individual tables. We replace one table by another by */ -/* switching these pointers. */ -word * GC_old_normal_bl; - /* Nonstack false references seen at last full */ - /* collection. */ -word * GC_incomplete_normal_bl; - /* Nonstack false references seen since last */ - /* full collection. */ -word * GC_old_stack_bl; -word * GC_incomplete_stack_bl; - -word GC_total_stack_black_listed; - -word GC_black_list_spacing = MINHINCR*HBLKSIZE; /* Initial rough guess */ - -void GC_clear_bl(); - -# if defined(__STDC__) || defined(__cplusplus) - void GC_default_print_heap_obj_proc(ptr_t p) -# else - void GC_default_print_heap_obj_proc(p) - ptr_t p; -# endif -{ - ptr_t base = GC_base(p); - - GC_err_printf2("start: 0x%lx, appr. length: %ld", base, GC_size(base)); -} - -void (*GC_print_heap_obj) GC_PROTO((ptr_t p)) = - GC_default_print_heap_obj_proc; - -void GC_print_source_ptr(p) -ptr_t p; -{ - ptr_t base = GC_base(p); - if (0 == base) { - if (0 == p) { - GC_err_printf0("in register"); - } else { - GC_err_printf0("in root set"); - } - } else { - GC_err_printf0("in object at "); - (*GC_print_heap_obj)(base); - } -} - -void GC_bl_init() -{ - if (!GC_all_interior_pointers) { - GC_old_normal_bl = (word *) - GC_scratch_alloc((word)(sizeof (page_hash_table))); - GC_incomplete_normal_bl = (word *)GC_scratch_alloc - ((word)(sizeof(page_hash_table))); - if (GC_old_normal_bl == 0 || GC_incomplete_normal_bl == 0) { - GC_err_printf0("Insufficient memory for black list\n"); - EXIT(); - } - GC_clear_bl(GC_old_normal_bl); - GC_clear_bl(GC_incomplete_normal_bl); - } - GC_old_stack_bl = (word *)GC_scratch_alloc((word)(sizeof(page_hash_table))); - GC_incomplete_stack_bl = (word *)GC_scratch_alloc - ((word)(sizeof(page_hash_table))); - if (GC_old_stack_bl == 0 || GC_incomplete_stack_bl == 0) { - GC_err_printf0("Insufficient memory for black list\n"); - EXIT(); - } - GC_clear_bl(GC_old_stack_bl); - GC_clear_bl(GC_incomplete_stack_bl); -} - -void GC_clear_bl(doomed) -word *doomed; -{ - BZERO(doomed, sizeof(page_hash_table)); -} - -void GC_copy_bl(old, new) -word *new, *old; -{ - BCOPY(old, new, sizeof(page_hash_table)); -} - -static word total_stack_black_listed(); - -/* Signal the completion of a collection. Turn the incomplete black */ -/* lists into new black lists, etc. */ -void GC_promote_black_lists() -{ - word * very_old_normal_bl = GC_old_normal_bl; - word * very_old_stack_bl = GC_old_stack_bl; - - GC_old_normal_bl = GC_incomplete_normal_bl; - GC_old_stack_bl = GC_incomplete_stack_bl; - if (!GC_all_interior_pointers) { - GC_clear_bl(very_old_normal_bl); - } - GC_clear_bl(very_old_stack_bl); - GC_incomplete_normal_bl = very_old_normal_bl; - GC_incomplete_stack_bl = very_old_stack_bl; - GC_total_stack_black_listed = total_stack_black_listed(); -# ifdef PRINTSTATS - GC_printf1("%ld bytes in heap blacklisted for interior pointers\n", - (unsigned long)GC_total_stack_black_listed); -# endif - if (GC_total_stack_black_listed != 0) { - GC_black_list_spacing = - HBLKSIZE*(GC_heapsize/GC_total_stack_black_listed); - } - if (GC_black_list_spacing < 3 * HBLKSIZE) { - GC_black_list_spacing = 3 * HBLKSIZE; - } - if (GC_black_list_spacing > MAXHINCR * HBLKSIZE) { - GC_black_list_spacing = MAXHINCR * HBLKSIZE; - /* Makes it easier to allocate really huge blocks, which otherwise */ - /* may have problems with nonuniform blacklist distributions. */ - /* This way we should always succeed immediately after growing the */ - /* heap. */ - } -} - -void GC_unpromote_black_lists() -{ - if (!GC_all_interior_pointers) { - GC_copy_bl(GC_old_normal_bl, GC_incomplete_normal_bl); - } - GC_copy_bl(GC_old_stack_bl, GC_incomplete_stack_bl); -} - -/* P is not a valid pointer reference, but it falls inside */ -/* the plausible heap bounds. */ -/* Add it to the normal incomplete black list if appropriate. */ -#ifdef PRINT_BLACK_LIST - void GC_add_to_black_list_normal(p, source) - ptr_t source; -#else - void GC_add_to_black_list_normal(p) -#endif -word p; -{ - if (!(GC_modws_valid_offsets[p & (sizeof(word)-1)])) return; - { - register int index = PHT_HASH(p); - - if (HDR(p) == 0 || get_pht_entry_from_index(GC_old_normal_bl, index)) { -# ifdef PRINT_BLACK_LIST - if (!get_pht_entry_from_index(GC_incomplete_normal_bl, index)) { - GC_err_printf2( - "Black listing (normal) 0x%lx referenced from 0x%lx ", - (unsigned long) p, (unsigned long) source); - GC_print_source_ptr(source); - GC_err_puts("\n"); - } -# endif - set_pht_entry_from_index(GC_incomplete_normal_bl, index); - } /* else this is probably just an interior pointer to an allocated */ - /* object, and isn't worth black listing. */ - } -} - -/* And the same for false pointers from the stack. */ -#ifdef PRINT_BLACK_LIST - void GC_add_to_black_list_stack(p, source) - ptr_t source; -#else - void GC_add_to_black_list_stack(p) -#endif -word p; -{ - register int index = PHT_HASH(p); - - if (HDR(p) == 0 || get_pht_entry_from_index(GC_old_stack_bl, index)) { -# ifdef PRINT_BLACK_LIST - if (!get_pht_entry_from_index(GC_incomplete_stack_bl, index)) { - GC_err_printf2( - "Black listing (stack) 0x%lx referenced from 0x%lx ", - (unsigned long)p, (unsigned long)source); - GC_print_source_ptr(source); - GC_err_puts("\n"); - } -# endif - set_pht_entry_from_index(GC_incomplete_stack_bl, index); - } -} - -/* - * Is the block starting at h of size len bytes black listed? If so, - * return the address of the next plausible r such that (r, len) might not - * be black listed. (R may not actually be in the heap. We guarantee only - * that every smaller value of r after h is also black listed.) - * If (h,len) is not black listed, return 0. - * Knows about the structure of the black list hash tables. - */ -struct hblk * GC_is_black_listed(h, len) -struct hblk * h; -word len; -{ - register int index = PHT_HASH((word)h); - register word i; - word nblocks = divHBLKSZ(len); - - if (!GC_all_interior_pointers) { - if (get_pht_entry_from_index(GC_old_normal_bl, index) - || get_pht_entry_from_index(GC_incomplete_normal_bl, index)) { - return(h+1); - } - } - - for (i = 0; ; ) { - if (GC_old_stack_bl[divWORDSZ(index)] == 0 - && GC_incomplete_stack_bl[divWORDSZ(index)] == 0) { - /* An easy case */ - i += WORDSZ - modWORDSZ(index); - } else { - if (get_pht_entry_from_index(GC_old_stack_bl, index) - || get_pht_entry_from_index(GC_incomplete_stack_bl, index)) { - return(h+i+1); - } - i++; - } - if (i >= nblocks) break; - index = PHT_HASH((word)(h+i)); - } - return(0); -} - - -/* Return the number of blacklisted blocks in a given range. */ -/* Used only for statistical purposes. */ -/* Looks only at the GC_incomplete_stack_bl. */ -word GC_number_stack_black_listed(start, endp1) -struct hblk *start, *endp1; -{ - register struct hblk * h; - word result = 0; - - for (h = start; h < endp1; h++) { - register int index = PHT_HASH((word)h); - - if (get_pht_entry_from_index(GC_old_stack_bl, index)) result++; - } - return(result); -} - - -/* Return the total number of (stack) black-listed bytes. */ -static word total_stack_black_listed() -{ - register unsigned i; - word total = 0; - - for (i = 0; i < GC_n_heap_sects; i++) { - struct hblk * start = (struct hblk *) GC_heap_sects[i].hs_start; - word len = (word) GC_heap_sects[i].hs_bytes; - struct hblk * endp1 = start + len/HBLKSIZE; - - total += GC_number_stack_black_listed(start, endp1); - } - return(total * HBLKSIZE); -} - |