Annotation of OpenXM_contrib2/asir2000/gc5.3/headers.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: * Copyright (c) 1996 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:
! 16: /*
! 17: * This implements:
! 18: * 1. allocation of heap block headers
! 19: * 2. A map from addresses to heap block addresses to heap block headers
! 20: *
! 21: * Access speed is crucial. We implement an index structure based on a 2
! 22: * level tree.
! 23: */
! 24:
! 25: # include "gc_priv.h"
! 26:
! 27: bottom_index * GC_all_bottom_indices = 0;
! 28: /* Pointer to first (lowest addr) */
! 29: /* bottom_index. */
! 30:
! 31: bottom_index * GC_all_bottom_indices_end = 0;
! 32: /* Pointer to last (highest addr) */
! 33: /* bottom_index. */
! 34:
! 35: /* Non-macro version of header location routine */
! 36: hdr * GC_find_header(h)
! 37: ptr_t h;
! 38: {
! 39: # ifdef HASH_TL
! 40: register hdr * result;
! 41: GET_HDR(h, result);
! 42: return(result);
! 43: # else
! 44: return(HDR_INNER(h));
! 45: # endif
! 46: }
! 47:
! 48: /* Routines to dynamically allocate collector data structures that will */
! 49: /* never be freed. */
! 50:
! 51: static ptr_t scratch_free_ptr = 0;
! 52:
! 53: /* GC_scratch_last_end_ptr is end point of last obtained scratch area. */
! 54: /* GC_scratch_end_ptr is end point of current scratch area. */
! 55:
! 56: ptr_t GC_scratch_alloc(bytes)
! 57: register word bytes;
! 58: {
! 59: register ptr_t result = scratch_free_ptr;
! 60:
! 61: # ifdef ALIGN_DOUBLE
! 62: # define GRANULARITY (2 * sizeof(word))
! 63: # else
! 64: # define GRANULARITY sizeof(word)
! 65: # endif
! 66: bytes += GRANULARITY-1;
! 67: bytes &= ~(GRANULARITY-1);
! 68: scratch_free_ptr += bytes;
! 69: if (scratch_free_ptr <= GC_scratch_end_ptr) {
! 70: return(result);
! 71: }
! 72: {
! 73: word bytes_to_get = MINHINCR * HBLKSIZE;
! 74:
! 75: if (bytes_to_get <= bytes) {
! 76: /* Undo the damage, and get memory directly */
! 77: bytes_to_get = bytes;
! 78: # ifdef USE_MMAP
! 79: bytes_to_get += GC_page_size - 1;
! 80: bytes_to_get &= ~(GC_page_size - 1);
! 81: # endif
! 82: result = (ptr_t)GET_MEM(bytes_to_get);
! 83: scratch_free_ptr -= bytes;
! 84: GC_scratch_last_end_ptr = result + bytes;
! 85: return(result);
! 86: }
! 87: result = (ptr_t)GET_MEM(bytes_to_get);
! 88: if (result == 0) {
! 89: # ifdef PRINTSTATS
! 90: GC_printf0("Out of memory - trying to allocate less\n");
! 91: # endif
! 92: scratch_free_ptr -= bytes;
! 93: bytes_to_get = bytes;
! 94: # ifdef USE_MMAP
! 95: bytes_to_get += GC_page_size - 1;
! 96: bytes_to_get &= ~(GC_page_size - 1);
! 97: # endif
! 98: return((ptr_t)GET_MEM(bytes_to_get));
! 99: }
! 100: scratch_free_ptr = result;
! 101: GC_scratch_end_ptr = scratch_free_ptr + bytes_to_get;
! 102: GC_scratch_last_end_ptr = GC_scratch_end_ptr;
! 103: return(GC_scratch_alloc(bytes));
! 104: }
! 105: }
! 106:
! 107: static hdr * hdr_free_list = 0;
! 108:
! 109: /* Return an uninitialized header */
! 110: static hdr * alloc_hdr()
! 111: {
! 112: register hdr * result;
! 113:
! 114: if (hdr_free_list == 0) {
! 115: result = (hdr *) GC_scratch_alloc((word)(sizeof(hdr)));
! 116: } else {
! 117: result = hdr_free_list;
! 118: hdr_free_list = (hdr *) (result -> hb_next);
! 119: }
! 120: return(result);
! 121: }
! 122:
! 123: static void free_hdr(hhdr)
! 124: hdr * hhdr;
! 125: {
! 126: hhdr -> hb_next = (struct hblk *) hdr_free_list;
! 127: hdr_free_list = hhdr;
! 128: }
! 129:
! 130: hdr * GC_invalid_header;
! 131:
! 132: #ifdef USE_HDR_CACHE
! 133: word GC_hdr_cache_hits = 0;
! 134: word GC_hdr_cache_misses = 0;
! 135: #endif
! 136:
! 137: void GC_init_headers()
! 138: {
! 139: register unsigned i;
! 140:
! 141: GC_all_nils = (bottom_index *)GC_scratch_alloc((word)sizeof(bottom_index));
! 142: BZERO(GC_all_nils, sizeof(bottom_index));
! 143: for (i = 0; i < TOP_SZ; i++) {
! 144: GC_top_index[i] = GC_all_nils;
! 145: }
! 146: GC_invalid_header = alloc_hdr();
! 147: GC_invalidate_map(GC_invalid_header);
! 148: }
! 149:
! 150: /* Make sure that there is a bottom level index block for address addr */
! 151: /* Return FALSE on failure. */
! 152: static GC_bool get_index(addr)
! 153: word addr;
! 154: {
! 155: word hi = (word)(addr) >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE);
! 156: bottom_index * r;
! 157: bottom_index * p;
! 158: bottom_index ** prev;
! 159: bottom_index *pi;
! 160:
! 161: # ifdef HASH_TL
! 162: unsigned i = TL_HASH(hi);
! 163: bottom_index * old;
! 164:
! 165: old = p = GC_top_index[i];
! 166: while(p != GC_all_nils) {
! 167: if (p -> key == hi) return(TRUE);
! 168: p = p -> hash_link;
! 169: }
! 170: r = (bottom_index*)GC_scratch_alloc((word)(sizeof (bottom_index)));
! 171: if (r == 0) return(FALSE);
! 172: BZERO(r, sizeof (bottom_index));
! 173: r -> hash_link = old;
! 174: GC_top_index[i] = r;
! 175: # else
! 176: if (GC_top_index[hi] != GC_all_nils) return(TRUE);
! 177: r = (bottom_index*)GC_scratch_alloc((word)(sizeof (bottom_index)));
! 178: if (r == 0) return(FALSE);
! 179: GC_top_index[hi] = r;
! 180: BZERO(r, sizeof (bottom_index));
! 181: # endif
! 182: r -> key = hi;
! 183: /* Add it to the list of bottom indices */
! 184: prev = &GC_all_bottom_indices; /* pointer to p */
! 185: pi = 0; /* bottom_index preceding p */
! 186: while ((p = *prev) != 0 && p -> key < hi) {
! 187: pi = p;
! 188: prev = &(p -> asc_link);
! 189: }
! 190: r -> desc_link = pi;
! 191: if (0 == p) {
! 192: GC_all_bottom_indices_end = r;
! 193: } else {
! 194: p -> desc_link = r;
! 195: }
! 196: r -> asc_link = p;
! 197: *prev = r;
! 198: return(TRUE);
! 199: }
! 200:
! 201: /* Install a header for block h. */
! 202: /* The header is uninitialized. */
! 203: /* Returns the header or 0 on failure. */
! 204: struct hblkhdr * GC_install_header(h)
! 205: register struct hblk * h;
! 206: {
! 207: hdr * result;
! 208:
! 209: if (!get_index((word) h)) return(FALSE);
! 210: result = alloc_hdr();
! 211: SET_HDR(h, result);
! 212: # ifdef USE_MUNMAP
! 213: result -> hb_last_reclaimed = GC_gc_no;
! 214: # endif
! 215: return(result);
! 216: }
! 217:
! 218: /* Set up forwarding counts for block h of size sz */
! 219: GC_bool GC_install_counts(h, sz)
! 220: register struct hblk * h;
! 221: register word sz; /* bytes */
! 222: {
! 223: register struct hblk * hbp;
! 224: register int i;
! 225:
! 226: for (hbp = h; (char *)hbp < (char *)h + sz; hbp += BOTTOM_SZ) {
! 227: if (!get_index((word) hbp)) return(FALSE);
! 228: }
! 229: if (!get_index((word)h + sz - 1)) return(FALSE);
! 230: for (hbp = h + 1; (char *)hbp < (char *)h + sz; hbp += 1) {
! 231: i = HBLK_PTR_DIFF(hbp, h);
! 232: SET_HDR(hbp, (hdr *)(i > MAX_JUMP? MAX_JUMP : i));
! 233: }
! 234: return(TRUE);
! 235: }
! 236:
! 237: /* Remove the header for block h */
! 238: void GC_remove_header(h)
! 239: register struct hblk * h;
! 240: {
! 241: hdr ** ha;
! 242:
! 243: GET_HDR_ADDR(h, ha);
! 244: free_hdr(*ha);
! 245: *ha = 0;
! 246: }
! 247:
! 248: /* Remove forwarding counts for h */
! 249: void GC_remove_counts(h, sz)
! 250: register struct hblk * h;
! 251: register word sz; /* bytes */
! 252: {
! 253: register struct hblk * hbp;
! 254:
! 255: for (hbp = h+1; (char *)hbp < (char *)h + sz; hbp += 1) {
! 256: SET_HDR(hbp, 0);
! 257: }
! 258: }
! 259:
! 260: /* Apply fn to all allocated blocks */
! 261: /*VARARGS1*/
! 262: void GC_apply_to_all_blocks(fn, client_data)
! 263: void (*fn)(/* struct hblk *h, word client_data */);
! 264: word client_data;
! 265: {
! 266: register int j;
! 267: register bottom_index * index_p;
! 268:
! 269: for (index_p = GC_all_bottom_indices; index_p != 0;
! 270: index_p = index_p -> asc_link) {
! 271: for (j = BOTTOM_SZ-1; j >= 0;) {
! 272: if (!IS_FORWARDING_ADDR_OR_NIL(index_p->index[j])) {
! 273: if (index_p->index[j]->hb_map != GC_invalid_map) {
! 274: (*fn)(((struct hblk *)
! 275: (((index_p->key << LOG_BOTTOM_SZ) + (word)j)
! 276: << LOG_HBLKSIZE)),
! 277: client_data);
! 278: }
! 279: j--;
! 280: } else if (index_p->index[j] == 0) {
! 281: j--;
! 282: } else {
! 283: j -= (word)(index_p->index[j]);
! 284: }
! 285: }
! 286: }
! 287: }
! 288:
! 289: /* Get the next valid block whose address is at least h */
! 290: /* Return 0 if there is none. */
! 291: struct hblk * GC_next_used_block(h)
! 292: struct hblk * h;
! 293: {
! 294: register bottom_index * bi;
! 295: register word j = ((word)h >> LOG_HBLKSIZE) & (BOTTOM_SZ-1);
! 296:
! 297: GET_BI(h, bi);
! 298: if (bi == GC_all_nils) {
! 299: register word hi = (word)h >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE);
! 300: bi = GC_all_bottom_indices;
! 301: while (bi != 0 && bi -> key < hi) bi = bi -> asc_link;
! 302: j = 0;
! 303: }
! 304: while(bi != 0) {
! 305: while (j < BOTTOM_SZ) {
! 306: hdr * hhdr = bi -> index[j];
! 307: if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
! 308: j++;
! 309: } else {
! 310: if (hhdr->hb_map != GC_invalid_map) {
! 311: return((struct hblk *)
! 312: (((bi -> key << LOG_BOTTOM_SZ) + j)
! 313: << LOG_HBLKSIZE));
! 314: } else {
! 315: j += divHBLKSZ(hhdr -> hb_sz);
! 316: }
! 317: }
! 318: }
! 319: j = 0;
! 320: bi = bi -> asc_link;
! 321: }
! 322: return(0);
! 323: }
! 324:
! 325: /* Get the last (highest address) block whose address is */
! 326: /* at most h. Return 0 if there is none. */
! 327: /* Unlike the above, this may return a free block. */
! 328: struct hblk * GC_prev_block(h)
! 329: struct hblk * h;
! 330: {
! 331: register bottom_index * bi;
! 332: register signed_word j = ((word)h >> LOG_HBLKSIZE) & (BOTTOM_SZ-1);
! 333:
! 334: GET_BI(h, bi);
! 335: if (bi == GC_all_nils) {
! 336: register word hi = (word)h >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE);
! 337: bi = GC_all_bottom_indices_end;
! 338: while (bi != 0 && bi -> key > hi) bi = bi -> desc_link;
! 339: j = BOTTOM_SZ - 1;
! 340: }
! 341: while(bi != 0) {
! 342: while (j >= 0) {
! 343: hdr * hhdr = bi -> index[j];
! 344: if (0 == hhdr) {
! 345: --j;
! 346: } else if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
! 347: j -= (signed_word)hhdr;
! 348: } else {
! 349: return((struct hblk *)
! 350: (((bi -> key << LOG_BOTTOM_SZ) + j)
! 351: << LOG_HBLKSIZE));
! 352: }
! 353: }
! 354: j = BOTTOM_SZ - 1;
! 355: bi = bi -> desc_link;
! 356: }
! 357: return(0);
! 358: }
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