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Diffstat (limited to '')
-rw-r--r-- | gc/headers.c | 358 |
1 files changed, 0 insertions, 358 deletions
diff --git a/gc/headers.c b/gc/headers.c deleted file mode 100644 index 0aa5139..0000000 --- a/gc/headers.c +++ /dev/null @@ -1,358 +0,0 @@ -/* - * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers - * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. - * Copyright (c) 1996 by Silicon Graphics. 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. - */ - -/* - * This implements: - * 1. allocation of heap block headers - * 2. A map from addresses to heap block addresses to heap block headers - * - * Access speed is crucial. We implement an index structure based on a 2 - * level tree. - */ - -# include "private/gc_priv.h" - -bottom_index * GC_all_bottom_indices = 0; - /* Pointer to first (lowest addr) */ - /* bottom_index. */ - -bottom_index * GC_all_bottom_indices_end = 0; - /* Pointer to last (highest addr) */ - /* bottom_index. */ - -/* Non-macro version of header location routine */ -hdr * GC_find_header(h) -ptr_t h; -{ -# ifdef HASH_TL - register hdr * result; - GET_HDR(h, result); - return(result); -# else - return(HDR_INNER(h)); -# endif -} - -/* Routines to dynamically allocate collector data structures that will */ -/* never be freed. */ - -static ptr_t scratch_free_ptr = 0; - -/* GC_scratch_last_end_ptr is end point of last obtained scratch area. */ -/* GC_scratch_end_ptr is end point of current scratch area. */ - -ptr_t GC_scratch_alloc(bytes) -register word bytes; -{ - register ptr_t result = scratch_free_ptr; - -# ifdef ALIGN_DOUBLE -# define GRANULARITY (2 * sizeof(word)) -# else -# define GRANULARITY sizeof(word) -# endif - bytes += GRANULARITY-1; - bytes &= ~(GRANULARITY-1); - scratch_free_ptr += bytes; - if (scratch_free_ptr <= GC_scratch_end_ptr) { - return(result); - } - { - word bytes_to_get = MINHINCR * HBLKSIZE; - - if (bytes_to_get <= bytes) { - /* Undo the damage, and get memory directly */ - bytes_to_get = bytes; -# ifdef USE_MMAP - bytes_to_get += GC_page_size - 1; - bytes_to_get &= ~(GC_page_size - 1); -# endif - result = (ptr_t)GET_MEM(bytes_to_get); - scratch_free_ptr -= bytes; - GC_scratch_last_end_ptr = result + bytes; - return(result); - } - result = (ptr_t)GET_MEM(bytes_to_get); - if (result == 0) { -# ifdef PRINTSTATS - GC_printf0("Out of memory - trying to allocate less\n"); -# endif - scratch_free_ptr -= bytes; - bytes_to_get = bytes; -# ifdef USE_MMAP - bytes_to_get += GC_page_size - 1; - bytes_to_get &= ~(GC_page_size - 1); -# endif - return((ptr_t)GET_MEM(bytes_to_get)); - } - scratch_free_ptr = result; - GC_scratch_end_ptr = scratch_free_ptr + bytes_to_get; - GC_scratch_last_end_ptr = GC_scratch_end_ptr; - return(GC_scratch_alloc(bytes)); - } -} - -static hdr * hdr_free_list = 0; - -/* Return an uninitialized header */ -static hdr * alloc_hdr() -{ - register hdr * result; - - if (hdr_free_list == 0) { - result = (hdr *) GC_scratch_alloc((word)(sizeof(hdr))); - } else { - result = hdr_free_list; - hdr_free_list = (hdr *) (result -> hb_next); - } - return(result); -} - -static void free_hdr(hhdr) -hdr * hhdr; -{ - hhdr -> hb_next = (struct hblk *) hdr_free_list; - hdr_free_list = hhdr; -} - -hdr * GC_invalid_header; - -#ifdef USE_HDR_CACHE - word GC_hdr_cache_hits = 0; - word GC_hdr_cache_misses = 0; -#endif - -void GC_init_headers() -{ - register unsigned i; - - GC_all_nils = (bottom_index *)GC_scratch_alloc((word)sizeof(bottom_index)); - BZERO(GC_all_nils, sizeof(bottom_index)); - for (i = 0; i < TOP_SZ; i++) { - GC_top_index[i] = GC_all_nils; - } - GC_invalid_header = alloc_hdr(); - GC_invalidate_map(GC_invalid_header); -} - -/* Make sure that there is a bottom level index block for address addr */ -/* Return FALSE on failure. */ -static GC_bool get_index(addr) -word addr; -{ - word hi = (word)(addr) >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE); - bottom_index * r; - bottom_index * p; - bottom_index ** prev; - bottom_index *pi; - -# ifdef HASH_TL - unsigned i = TL_HASH(hi); - bottom_index * old; - - old = p = GC_top_index[i]; - while(p != GC_all_nils) { - if (p -> key == hi) return(TRUE); - p = p -> hash_link; - } - r = (bottom_index*)GC_scratch_alloc((word)(sizeof (bottom_index))); - if (r == 0) return(FALSE); - BZERO(r, sizeof (bottom_index)); - r -> hash_link = old; - GC_top_index[i] = r; -# else - if (GC_top_index[hi] != GC_all_nils) return(TRUE); - r = (bottom_index*)GC_scratch_alloc((word)(sizeof (bottom_index))); - if (r == 0) return(FALSE); - GC_top_index[hi] = r; - BZERO(r, sizeof (bottom_index)); -# endif - r -> key = hi; - /* Add it to the list of bottom indices */ - prev = &GC_all_bottom_indices; /* pointer to p */ - pi = 0; /* bottom_index preceding p */ - while ((p = *prev) != 0 && p -> key < hi) { - pi = p; - prev = &(p -> asc_link); - } - r -> desc_link = pi; - if (0 == p) { - GC_all_bottom_indices_end = r; - } else { - p -> desc_link = r; - } - r -> asc_link = p; - *prev = r; - return(TRUE); -} - -/* Install a header for block h. */ -/* The header is uninitialized. */ -/* Returns the header or 0 on failure. */ -struct hblkhdr * GC_install_header(h) -register struct hblk * h; -{ - hdr * result; - - if (!get_index((word) h)) return(FALSE); - result = alloc_hdr(); - SET_HDR(h, result); -# ifdef USE_MUNMAP - result -> hb_last_reclaimed = GC_gc_no; -# endif - return(result); -} - -/* Set up forwarding counts for block h of size sz */ -GC_bool GC_install_counts(h, sz) -register struct hblk * h; -register word sz; /* bytes */ -{ - register struct hblk * hbp; - register int i; - - for (hbp = h; (char *)hbp < (char *)h + sz; hbp += BOTTOM_SZ) { - if (!get_index((word) hbp)) return(FALSE); - } - if (!get_index((word)h + sz - 1)) return(FALSE); - for (hbp = h + 1; (char *)hbp < (char *)h + sz; hbp += 1) { - i = HBLK_PTR_DIFF(hbp, h); - SET_HDR(hbp, (hdr *)(i > MAX_JUMP? MAX_JUMP : i)); - } - return(TRUE); -} - -/* Remove the header for block h */ -void GC_remove_header(h) -register struct hblk * h; -{ - hdr ** ha; - - GET_HDR_ADDR(h, ha); - free_hdr(*ha); - *ha = 0; -} - -/* Remove forwarding counts for h */ -void GC_remove_counts(h, sz) -register struct hblk * h; -register word sz; /* bytes */ -{ - register struct hblk * hbp; - - for (hbp = h+1; (char *)hbp < (char *)h + sz; hbp += 1) { - SET_HDR(hbp, 0); - } -} - -/* Apply fn to all allocated blocks */ -/*VARARGS1*/ -void GC_apply_to_all_blocks(fn, client_data) -void (*fn) GC_PROTO((struct hblk *h, word client_data)); -word client_data; -{ - register int j; - register bottom_index * index_p; - - for (index_p = GC_all_bottom_indices; index_p != 0; - index_p = index_p -> asc_link) { - for (j = BOTTOM_SZ-1; j >= 0;) { - if (!IS_FORWARDING_ADDR_OR_NIL(index_p->index[j])) { - if (index_p->index[j]->hb_map != GC_invalid_map) { - (*fn)(((struct hblk *) - (((index_p->key << LOG_BOTTOM_SZ) + (word)j) - << LOG_HBLKSIZE)), - client_data); - } - j--; - } else if (index_p->index[j] == 0) { - j--; - } else { - j -= (word)(index_p->index[j]); - } - } - } -} - -/* Get the next valid block whose address is at least h */ -/* Return 0 if there is none. */ -struct hblk * GC_next_used_block(h) -struct hblk * h; -{ - register bottom_index * bi; - register word j = ((word)h >> LOG_HBLKSIZE) & (BOTTOM_SZ-1); - - GET_BI(h, bi); - if (bi == GC_all_nils) { - register word hi = (word)h >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE); - bi = GC_all_bottom_indices; - while (bi != 0 && bi -> key < hi) bi = bi -> asc_link; - j = 0; - } - while(bi != 0) { - while (j < BOTTOM_SZ) { - hdr * hhdr = bi -> index[j]; - if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { - j++; - } else { - if (hhdr->hb_map != GC_invalid_map) { - return((struct hblk *) - (((bi -> key << LOG_BOTTOM_SZ) + j) - << LOG_HBLKSIZE)); - } else { - j += divHBLKSZ(hhdr -> hb_sz); - } - } - } - j = 0; - bi = bi -> asc_link; - } - return(0); -} - -/* Get the last (highest address) block whose address is */ -/* at most h. Return 0 if there is none. */ -/* Unlike the above, this may return a free block. */ -struct hblk * GC_prev_block(h) -struct hblk * h; -{ - register bottom_index * bi; - register signed_word j = ((word)h >> LOG_HBLKSIZE) & (BOTTOM_SZ-1); - - GET_BI(h, bi); - if (bi == GC_all_nils) { - register word hi = (word)h >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE); - bi = GC_all_bottom_indices_end; - while (bi != 0 && bi -> key > hi) bi = bi -> desc_link; - j = BOTTOM_SZ - 1; - } - while(bi != 0) { - while (j >= 0) { - hdr * hhdr = bi -> index[j]; - if (0 == hhdr) { - --j; - } else if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { - j -= (signed_word)hhdr; - } else { - return((struct hblk *) - (((bi -> key << LOG_BOTTOM_SZ) + j) - << LOG_HBLKSIZE)); - } - } - j = BOTTOM_SZ - 1; - bi = bi -> desc_link; - } - return(0); -} |