+++ /dev/null
-/*
- * 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);
-}
-
projects / msp430-gcc.git / blobdiff