Annotation of OpenXM_contrib2/asir2000/gc/blacklst.c, Revision 1.1
1.1 ! noro 1: /*
! 2: * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
! 3: * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
! 4: *
! 5: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
! 6: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
! 7: *
! 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.
! 13: */
! 14: /* Boehm, August 9, 1995 6:09 pm PDT */
! 15: # include "gc_priv.h"
! 16:
! 17: /*
! 18: * We maintain several hash tables of hblks that have had false hits.
! 19: * Each contains one bit per hash bucket; If any page in the bucket
! 20: * has had a false hit, we assume that all of them have.
! 21: * See the definition of page_hash_table in gc_private.h.
! 22: * False hits from the stack(s) are much more dangerous than false hits
! 23: * from elsewhere, since the former can pin a large object that spans the
! 24: * block, eventhough it does not start on the dangerous block.
! 25: */
! 26:
! 27: /*
! 28: * Externally callable routines are:
! 29:
! 30: * GC_add_to_black_list_normal
! 31: * GC_add_to_black_list_stack
! 32: * GC_promote_black_lists
! 33: * GC_is_black_listed
! 34: *
! 35: * All require that the allocator lock is held.
! 36: */
! 37:
! 38: /* Pointers to individual tables. We replace one table by another by */
! 39: /* switching these pointers. */
! 40: word * GC_old_normal_bl;
! 41: /* Nonstack false references seen at last full */
! 42: /* collection. */
! 43: word * GC_incomplete_normal_bl;
! 44: /* Nonstack false references seen since last */
! 45: /* full collection. */
! 46: word * GC_old_stack_bl;
! 47: word * GC_incomplete_stack_bl;
! 48:
! 49: word GC_total_stack_black_listed;
! 50:
! 51: word GC_black_list_spacing = MINHINCR*HBLKSIZE; /* Initial rough guess */
! 52:
! 53: void GC_clear_bl();
! 54:
! 55: void GC_default_print_heap_obj_proc(p)
! 56: ptr_t p;
! 57: {
! 58: ptr_t base = GC_base(p);
! 59:
! 60: GC_err_printf2("start: 0x%lx, appr. length: %ld", base, GC_size(base));
! 61: }
! 62:
! 63: void (*GC_print_heap_obj)(/* char * s, ptr_t p */) =
! 64: GC_default_print_heap_obj_proc;
! 65:
! 66: void GC_print_source_ptr(p)
! 67: ptr_t p;
! 68: {
! 69: ptr_t base = GC_base(p);
! 70: if (0 == base) {
! 71: if (0 == p) {
! 72: GC_err_printf0("in register");
! 73: } else {
! 74: GC_err_printf0("in root set");
! 75: }
! 76: } else {
! 77: GC_err_printf0("in object at ");
! 78: (*GC_print_heap_obj)(base);
! 79: }
! 80: }
! 81:
! 82: void GC_bl_init()
! 83: {
! 84: # ifndef ALL_INTERIOR_POINTERS
! 85: GC_old_normal_bl = (word *)
! 86: GC_scratch_alloc((word)(sizeof (page_hash_table)));
! 87: GC_incomplete_normal_bl = (word *)GC_scratch_alloc
! 88: ((word)(sizeof(page_hash_table)));
! 89: if (GC_old_normal_bl == 0 || GC_incomplete_normal_bl == 0) {
! 90: GC_err_printf0("Insufficient memory for black list\n");
! 91: EXIT();
! 92: }
! 93: GC_clear_bl(GC_old_normal_bl);
! 94: GC_clear_bl(GC_incomplete_normal_bl);
! 95: # endif
! 96: GC_old_stack_bl = (word *)GC_scratch_alloc((word)(sizeof(page_hash_table)));
! 97: GC_incomplete_stack_bl = (word *)GC_scratch_alloc
! 98: ((word)(sizeof(page_hash_table)));
! 99: if (GC_old_stack_bl == 0 || GC_incomplete_stack_bl == 0) {
! 100: GC_err_printf0("Insufficient memory for black list\n");
! 101: EXIT();
! 102: }
! 103: GC_clear_bl(GC_old_stack_bl);
! 104: GC_clear_bl(GC_incomplete_stack_bl);
! 105: }
! 106:
! 107: void GC_clear_bl(doomed)
! 108: word *doomed;
! 109: {
! 110: BZERO(doomed, sizeof(page_hash_table));
! 111: }
! 112:
! 113: void GC_copy_bl(old, new)
! 114: word *new, *old;
! 115: {
! 116: BCOPY(old, new, sizeof(page_hash_table));
! 117: }
! 118:
! 119: static word total_stack_black_listed();
! 120:
! 121: /* Signal the completion of a collection. Turn the incomplete black */
! 122: /* lists into new black lists, etc. */
! 123: void GC_promote_black_lists()
! 124: {
! 125: word * very_old_normal_bl = GC_old_normal_bl;
! 126: word * very_old_stack_bl = GC_old_stack_bl;
! 127:
! 128: GC_old_normal_bl = GC_incomplete_normal_bl;
! 129: GC_old_stack_bl = GC_incomplete_stack_bl;
! 130: # ifndef ALL_INTERIOR_POINTERS
! 131: GC_clear_bl(very_old_normal_bl);
! 132: # endif
! 133: GC_clear_bl(very_old_stack_bl);
! 134: GC_incomplete_normal_bl = very_old_normal_bl;
! 135: GC_incomplete_stack_bl = very_old_stack_bl;
! 136: GC_total_stack_black_listed = total_stack_black_listed();
! 137: # ifdef PRINTSTATS
! 138: GC_printf1("%ld bytes in heap blacklisted for interior pointers\n",
! 139: (unsigned long)GC_total_stack_black_listed);
! 140: # endif
! 141: if (GC_total_stack_black_listed != 0) {
! 142: GC_black_list_spacing =
! 143: HBLKSIZE*(GC_heapsize/GC_total_stack_black_listed);
! 144: }
! 145: if (GC_black_list_spacing < 3 * HBLKSIZE) {
! 146: GC_black_list_spacing = 3 * HBLKSIZE;
! 147: }
! 148: }
! 149:
! 150: void GC_unpromote_black_lists()
! 151: {
! 152: # ifndef ALL_INTERIOR_POINTERS
! 153: GC_copy_bl(GC_old_normal_bl, GC_incomplete_normal_bl);
! 154: # endif
! 155: GC_copy_bl(GC_old_stack_bl, GC_incomplete_stack_bl);
! 156: }
! 157:
! 158: # ifndef ALL_INTERIOR_POINTERS
! 159: /* P is not a valid pointer reference, but it falls inside */
! 160: /* the plausible heap bounds. */
! 161: /* Add it to the normal incomplete black list if appropriate. */
! 162: #ifdef PRINT_BLACK_LIST
! 163: void GC_add_to_black_list_normal(p, source)
! 164: ptr_t source;
! 165: #else
! 166: void GC_add_to_black_list_normal(p)
! 167: #endif
! 168: word p;
! 169: {
! 170: if (!(GC_modws_valid_offsets[p & (sizeof(word)-1)])) return;
! 171: {
! 172: register int index = PHT_HASH(p);
! 173:
! 174: if (HDR(p) == 0 || get_pht_entry_from_index(GC_old_normal_bl, index)) {
! 175: # ifdef PRINT_BLACK_LIST
! 176: if (!get_pht_entry_from_index(GC_incomplete_normal_bl, index)) {
! 177: GC_err_printf2(
! 178: "Black listing (normal) 0x%lx referenced from 0x%lx ",
! 179: (unsigned long) p, (unsigned long) source);
! 180: GC_print_source_ptr(source);
! 181: GC_err_puts("\n");
! 182: }
! 183: # endif
! 184: set_pht_entry_from_index(GC_incomplete_normal_bl, index);
! 185: } /* else this is probably just an interior pointer to an allocated */
! 186: /* object, and isn't worth black listing. */
! 187: }
! 188: }
! 189: # endif
! 190:
! 191: /* And the same for false pointers from the stack. */
! 192: #ifdef PRINT_BLACK_LIST
! 193: void GC_add_to_black_list_stack(p, source)
! 194: ptr_t source;
! 195: #else
! 196: void GC_add_to_black_list_stack(p)
! 197: #endif
! 198: word p;
! 199: {
! 200: register int index = PHT_HASH(p);
! 201:
! 202: if (HDR(p) == 0 || get_pht_entry_from_index(GC_old_stack_bl, index)) {
! 203: # ifdef PRINT_BLACK_LIST
! 204: if (!get_pht_entry_from_index(GC_incomplete_stack_bl, index)) {
! 205: GC_err_printf2(
! 206: "Black listing (stack) 0x%lx referenced from 0x%lx ",
! 207: (unsigned long)p, (unsigned long)source);
! 208: GC_print_source_ptr(source);
! 209: GC_err_puts("\n");
! 210: }
! 211: # endif
! 212: set_pht_entry_from_index(GC_incomplete_stack_bl, index);
! 213: }
! 214: }
! 215:
! 216: /*
! 217: * Is the block starting at h of size len bytes black listed? If so,
! 218: * return the address of the next plausible r such that (r, len) might not
! 219: * be black listed. (R may not actually be in the heap. We guarantee only
! 220: * that every smaller value of r after h is also black listed.)
! 221: * If (h,len) is not black listed, return 0.
! 222: * Knows about the structure of the black list hash tables.
! 223: */
! 224: struct hblk * GC_is_black_listed(h, len)
! 225: struct hblk * h;
! 226: word len;
! 227: {
! 228: register int index = PHT_HASH((word)h);
! 229: register word i;
! 230: word nblocks = divHBLKSZ(len);
! 231:
! 232: # ifndef ALL_INTERIOR_POINTERS
! 233: if (get_pht_entry_from_index(GC_old_normal_bl, index)
! 234: || get_pht_entry_from_index(GC_incomplete_normal_bl, index)) {
! 235: return(h+1);
! 236: }
! 237: # endif
! 238:
! 239: for (i = 0; ; ) {
! 240: if (GC_old_stack_bl[divWORDSZ(index)] == 0
! 241: && GC_incomplete_stack_bl[divWORDSZ(index)] == 0) {
! 242: /* An easy case */
! 243: i += WORDSZ - modWORDSZ(index);
! 244: } else {
! 245: if (get_pht_entry_from_index(GC_old_stack_bl, index)
! 246: || get_pht_entry_from_index(GC_incomplete_stack_bl, index)) {
! 247: return(h+i+1);
! 248: }
! 249: i++;
! 250: }
! 251: if (i >= nblocks) break;
! 252: index = PHT_HASH((word)(h+i));
! 253: }
! 254: return(0);
! 255: }
! 256:
! 257:
! 258: /* Return the number of blacklisted blocks in a given range. */
! 259: /* Used only for statistical purposes. */
! 260: /* Looks only at the GC_incomplete_stack_bl. */
! 261: word GC_number_stack_black_listed(start, endp1)
! 262: struct hblk *start, *endp1;
! 263: {
! 264: register struct hblk * h;
! 265: word result = 0;
! 266:
! 267: for (h = start; h < endp1; h++) {
! 268: register int index = PHT_HASH((word)h);
! 269:
! 270: if (get_pht_entry_from_index(GC_old_stack_bl, index)) result++;
! 271: }
! 272: return(result);
! 273: }
! 274:
! 275:
! 276: /* Return the total number of (stack) black-listed bytes. */
! 277: static word total_stack_black_listed()
! 278: {
! 279: register unsigned i;
! 280: word total = 0;
! 281:
! 282: for (i = 0; i < GC_n_heap_sects; i++) {
! 283: struct hblk * start = (struct hblk *) GC_heap_sects[i].hs_start;
! 284: word len = (word) GC_heap_sects[i].hs_bytes;
! 285: struct hblk * endp1 = start + len/HBLKSIZE;
! 286:
! 287: total += GC_number_stack_black_listed(start, endp1);
! 288: }
! 289: return(total * HBLKSIZE);
! 290: }
! 291:
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