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Diffstat (limited to '')
| -rw-r--r-- | gc/allchblk.c | 821 |
1 files changed, 0 insertions, 821 deletions
diff --git a/gc/allchblk.c b/gc/allchblk.c deleted file mode 100644 index 2b03939..0000000 --- a/gc/allchblk.c +++ /dev/null @@ -1,821 +0,0 @@ -/* - * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers - * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. - * Copyright (c) 1998-1999 by Silicon Graphics. All rights reserved. - * Copyright (c) 1999 by Hewlett-Packard Company. 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. - */ - -/* #define DEBUG */ -#include <stdio.h> -#include "private/gc_priv.h" - -GC_bool GC_use_entire_heap = 0; - -/* - * Free heap blocks are kept on one of several free lists, - * depending on the size of the block. Each free list is doubly linked. - * Adjacent free blocks are coalesced. - */ - - -# define MAX_BLACK_LIST_ALLOC (2*HBLKSIZE) - /* largest block we will allocate starting on a black */ - /* listed block. Must be >= HBLKSIZE. */ - - -# define UNIQUE_THRESHOLD 32 - /* Sizes up to this many HBLKs each have their own free list */ -# define HUGE_THRESHOLD 256 - /* Sizes of at least this many heap blocks are mapped to a */ - /* single free list. */ -# define FL_COMPRESSION 8 - /* In between sizes map this many distinct sizes to a single */ - /* bin. */ - -# define N_HBLK_FLS (HUGE_THRESHOLD - UNIQUE_THRESHOLD)/FL_COMPRESSION \ - + UNIQUE_THRESHOLD - -struct hblk * GC_hblkfreelist[N_HBLK_FLS+1] = { 0 }; - -#ifndef USE_MUNMAP - - word GC_free_bytes[N_HBLK_FLS+1] = { 0 }; - /* Number of free bytes on each list. */ - - /* Is bytes + the number of free bytes on lists n .. N_HBLK_FLS */ - /* > GC_max_large_allocd_bytes? */ -# ifdef __GNUC__ - __inline__ -# endif - static GC_bool GC_enough_large_bytes_left(bytes,n) - word bytes; - int n; - { - int i; - for (i = N_HBLK_FLS; i >= n; --i) { - bytes += GC_free_bytes[i]; - if (bytes > GC_max_large_allocd_bytes) return TRUE; - } - return FALSE; - } - -# define INCR_FREE_BYTES(n, b) GC_free_bytes[n] += (b); - -# define FREE_ASSERT(e) GC_ASSERT(e) - -#else /* USE_MUNMAP */ - -# define INCR_FREE_BYTES(n, b) -# define FREE_ASSERT(e) - -#endif /* USE_MUNMAP */ - -/* Map a number of blocks to the appropriate large block free list index. */ -int GC_hblk_fl_from_blocks(blocks_needed) -word blocks_needed; -{ - if (blocks_needed <= UNIQUE_THRESHOLD) return blocks_needed; - if (blocks_needed >= HUGE_THRESHOLD) return N_HBLK_FLS; - return (blocks_needed - UNIQUE_THRESHOLD)/FL_COMPRESSION - + UNIQUE_THRESHOLD; - -} - -# define PHDR(hhdr) HDR(hhdr -> hb_prev) -# define NHDR(hhdr) HDR(hhdr -> hb_next) - -# ifdef USE_MUNMAP -# define IS_MAPPED(hhdr) (((hhdr) -> hb_flags & WAS_UNMAPPED) == 0) -# else /* !USE_MMAP */ -# define IS_MAPPED(hhdr) 1 -# endif /* USE_MUNMAP */ - -# if !defined(NO_DEBUGGING) -void GC_print_hblkfreelist() -{ - struct hblk * h; - word total_free = 0; - hdr * hhdr; - word sz; - int i; - - for (i = 0; i <= N_HBLK_FLS; ++i) { - h = GC_hblkfreelist[i]; -# ifdef USE_MUNMAP - if (0 != h) GC_printf1("Free list %ld (Total size %ld):\n", - (unsigned long)i); -# else - if (0 != h) GC_printf2("Free list %ld (Total size %ld):\n", - (unsigned long)i, - (unsigned long)GC_free_bytes[i]); -# endif - while (h != 0) { - hhdr = HDR(h); - sz = hhdr -> hb_sz; - GC_printf2("\t0x%lx size %lu ", (unsigned long)h, (unsigned long)sz); - total_free += sz; - if (GC_is_black_listed(h, HBLKSIZE) != 0) { - GC_printf0("start black listed\n"); - } else if (GC_is_black_listed(h, hhdr -> hb_sz) != 0) { - GC_printf0("partially black listed\n"); - } else { - GC_printf0("not black listed\n"); - } - h = hhdr -> hb_next; - } - } - if (total_free != GC_large_free_bytes) { - GC_printf1("GC_large_free_bytes = %lu (INCONSISTENT!!)\n", - (unsigned long) GC_large_free_bytes); - } - GC_printf1("Total of %lu bytes on free list\n", (unsigned long)total_free); -} - -/* Return the free list index on which the block described by the header */ -/* appears, or -1 if it appears nowhere. */ -int free_list_index_of(wanted) -hdr * wanted; -{ - struct hblk * h; - hdr * hhdr; - int i; - - for (i = 0; i <= N_HBLK_FLS; ++i) { - h = GC_hblkfreelist[i]; - while (h != 0) { - hhdr = HDR(h); - if (hhdr == wanted) return i; - h = hhdr -> hb_next; - } - } - return -1; -} - -void GC_dump_regions() -{ - unsigned i; - ptr_t start, end; - ptr_t p; - size_t bytes; - hdr *hhdr; - for (i = 0; i < GC_n_heap_sects; ++i) { - start = GC_heap_sects[i].hs_start; - bytes = GC_heap_sects[i].hs_bytes; - end = start + bytes; - /* Merge in contiguous sections. */ - while (i+1 < GC_n_heap_sects && GC_heap_sects[i+1].hs_start == end) { - ++i; - end = GC_heap_sects[i].hs_start + GC_heap_sects[i].hs_bytes; - } - GC_printf2("***Section from 0x%lx to 0x%lx\n", start, end); - for (p = start; p < end;) { - hhdr = HDR(p); - GC_printf1("\t0x%lx ", (unsigned long)p); - if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { - GC_printf1("Missing header!!\n", hhdr); - p += HBLKSIZE; - continue; - } - if (HBLK_IS_FREE(hhdr)) { - int correct_index = GC_hblk_fl_from_blocks( - divHBLKSZ(hhdr -> hb_sz)); - int actual_index; - - GC_printf1("\tfree block of size 0x%lx bytes", - (unsigned long)(hhdr -> hb_sz)); - if (IS_MAPPED(hhdr)) { - GC_printf0("\n"); - } else { - GC_printf0("(unmapped)\n"); - } - actual_index = free_list_index_of(hhdr); - if (-1 == actual_index) { - GC_printf1("\t\tBlock not on free list %ld!!\n", - correct_index); - } else if (correct_index != actual_index) { - GC_printf2("\t\tBlock on list %ld, should be on %ld!!\n", - actual_index, correct_index); - } - p += hhdr -> hb_sz; - } else { - GC_printf1("\tused for blocks of size 0x%lx bytes\n", - (unsigned long)WORDS_TO_BYTES(hhdr -> hb_sz)); - p += HBLKSIZE * OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz); - } - } - } -} - -# endif /* NO_DEBUGGING */ - -/* Initialize hdr for a block containing the indicated size and */ -/* kind of objects. */ -/* Return FALSE on failure. */ -static GC_bool setup_header(hhdr, sz, kind, flags) -register hdr * hhdr; -word sz; /* object size in words */ -int kind; -unsigned char flags; -{ - register word descr; - - /* Add description of valid object pointers */ - if (!GC_add_map_entry(sz)) return(FALSE); - hhdr -> hb_map = GC_obj_map[sz > MAXOBJSZ? 0 : sz]; - - /* Set size, kind and mark proc fields */ - hhdr -> hb_sz = sz; - hhdr -> hb_obj_kind = kind; - hhdr -> hb_flags = flags; - descr = GC_obj_kinds[kind].ok_descriptor; - if (GC_obj_kinds[kind].ok_relocate_descr) descr += WORDS_TO_BYTES(sz); - hhdr -> hb_descr = descr; - - /* Clear mark bits */ - GC_clear_hdr_marks(hhdr); - - hhdr -> hb_last_reclaimed = (unsigned short)GC_gc_no; - return(TRUE); -} - -#define FL_UNKNOWN -1 -/* - * Remove hhdr from the appropriate free list. - * We assume it is on the nth free list, or on the size - * appropriate free list if n is FL_UNKNOWN. - */ -void GC_remove_from_fl(hhdr, n) -hdr * hhdr; -int n; -{ - int index; - - GC_ASSERT(((hhdr -> hb_sz) & (HBLKSIZE-1)) == 0); -# ifndef USE_MUNMAP - /* We always need index to mainatin free counts. */ - if (FL_UNKNOWN == n) { - index = GC_hblk_fl_from_blocks(divHBLKSZ(hhdr -> hb_sz)); - } else { - index = n; - } -# endif - if (hhdr -> hb_prev == 0) { -# ifdef USE_MUNMAP - if (FL_UNKNOWN == n) { - index = GC_hblk_fl_from_blocks(divHBLKSZ(hhdr -> hb_sz)); - } else { - index = n; - } -# endif - GC_ASSERT(HDR(GC_hblkfreelist[index]) == hhdr); - GC_hblkfreelist[index] = hhdr -> hb_next; - } else { - hdr *phdr; - GET_HDR(hhdr -> hb_prev, phdr); - phdr -> hb_next = hhdr -> hb_next; - } - INCR_FREE_BYTES(index, - (signed_word)(hhdr -> hb_sz)); - FREE_ASSERT(GC_free_bytes[index] >= 0); - if (0 != hhdr -> hb_next) { - hdr * nhdr; - GC_ASSERT(!IS_FORWARDING_ADDR_OR_NIL(NHDR(hhdr))); - GET_HDR(hhdr -> hb_next, nhdr); - nhdr -> hb_prev = hhdr -> hb_prev; - } -} - -/* - * Return a pointer to the free block ending just before h, if any. - */ -struct hblk * GC_free_block_ending_at(h) -struct hblk *h; -{ - struct hblk * p = h - 1; - hdr * phdr; - - GET_HDR(p, phdr); - while (0 != phdr && IS_FORWARDING_ADDR_OR_NIL(phdr)) { - p = FORWARDED_ADDR(p,phdr); - phdr = HDR(p); - } - if (0 != phdr) { - if(HBLK_IS_FREE(phdr)) { - return p; - } else { - return 0; - } - } - p = GC_prev_block(h - 1); - if (0 != p) { - phdr = HDR(p); - if (HBLK_IS_FREE(phdr) && (ptr_t)p + phdr -> hb_sz == (ptr_t)h) { - return p; - } - } - return 0; -} - -/* - * Add hhdr to the appropriate free list. - * We maintain individual free lists sorted by address. - */ -void GC_add_to_fl(h, hhdr) -struct hblk *h; -hdr * hhdr; -{ - int index = GC_hblk_fl_from_blocks(divHBLKSZ(hhdr -> hb_sz)); - struct hblk *second = GC_hblkfreelist[index]; - hdr * second_hdr; -# ifdef GC_ASSERTIONS - struct hblk *next = (struct hblk *)((word)h + hhdr -> hb_sz); - hdr * nexthdr = HDR(next); - struct hblk *prev = GC_free_block_ending_at(h); - hdr * prevhdr = HDR(prev); - GC_ASSERT(nexthdr == 0 || !HBLK_IS_FREE(nexthdr) || !IS_MAPPED(nexthdr)); - GC_ASSERT(prev == 0 || !HBLK_IS_FREE(prevhdr) || !IS_MAPPED(prevhdr)); -# endif - GC_ASSERT(((hhdr -> hb_sz) & (HBLKSIZE-1)) == 0); - GC_hblkfreelist[index] = h; - INCR_FREE_BYTES(index, hhdr -> hb_sz); - FREE_ASSERT(GC_free_bytes[index] <= GC_large_free_bytes) - hhdr -> hb_next = second; - hhdr -> hb_prev = 0; - if (0 != second) { - GET_HDR(second, second_hdr); - second_hdr -> hb_prev = h; - } - GC_invalidate_map(hhdr); -} - -#ifdef USE_MUNMAP - -/* Unmap blocks that haven't been recently touched. This is the only way */ -/* way blocks are ever unmapped. */ -void GC_unmap_old(void) -{ - struct hblk * h; - hdr * hhdr; - word sz; - unsigned short last_rec, threshold; - int i; -# define UNMAP_THRESHOLD 6 - - for (i = 0; i <= N_HBLK_FLS; ++i) { - for (h = GC_hblkfreelist[i]; 0 != h; h = hhdr -> hb_next) { - hhdr = HDR(h); - if (!IS_MAPPED(hhdr)) continue; - threshold = (unsigned short)(GC_gc_no - UNMAP_THRESHOLD); - last_rec = hhdr -> hb_last_reclaimed; - if (last_rec > GC_gc_no - || last_rec < threshold && threshold < GC_gc_no - /* not recently wrapped */) { - sz = hhdr -> hb_sz; - GC_unmap((ptr_t)h, sz); - hhdr -> hb_flags |= WAS_UNMAPPED; - } - } - } -} - -/* Merge all unmapped blocks that are adjacent to other free */ -/* blocks. This may involve remapping, since all blocks are either */ -/* fully mapped or fully unmapped. */ -void GC_merge_unmapped(void) -{ - struct hblk * h, *next; - hdr * hhdr, *nexthdr; - word size, nextsize; - int i; - - for (i = 0; i <= N_HBLK_FLS; ++i) { - h = GC_hblkfreelist[i]; - while (h != 0) { - GET_HDR(h, hhdr); - size = hhdr->hb_sz; - next = (struct hblk *)((word)h + size); - GET_HDR(next, nexthdr); - /* Coalesce with successor, if possible */ - if (0 != nexthdr && HBLK_IS_FREE(nexthdr)) { - nextsize = nexthdr -> hb_sz; - if (IS_MAPPED(hhdr)) { - GC_ASSERT(!IS_MAPPED(nexthdr)); - /* make both consistent, so that we can merge */ - if (size > nextsize) { - GC_remap((ptr_t)next, nextsize); - } else { - GC_unmap((ptr_t)h, size); - hhdr -> hb_flags |= WAS_UNMAPPED; - } - } else if (IS_MAPPED(nexthdr)) { - GC_ASSERT(!IS_MAPPED(hhdr)); - if (size > nextsize) { - GC_unmap((ptr_t)next, nextsize); - } else { - GC_remap((ptr_t)h, size); - hhdr -> hb_flags &= ~WAS_UNMAPPED; - } - } else { - /* Unmap any gap in the middle */ - GC_unmap_gap((ptr_t)h, size, (ptr_t)next, nexthdr -> hb_sz); - } - /* If they are both unmapped, we merge, but leave unmapped. */ - GC_remove_from_fl(hhdr, i); - GC_remove_from_fl(nexthdr, FL_UNKNOWN); - hhdr -> hb_sz += nexthdr -> hb_sz; - GC_remove_header(next); - GC_add_to_fl(h, hhdr); - /* Start over at beginning of list */ - h = GC_hblkfreelist[i]; - } else /* not mergable with successor */ { - h = hhdr -> hb_next; - } - } /* while (h != 0) ... */ - } /* for ... */ -} - -#endif /* USE_MUNMAP */ - -/* - * Return a pointer to a block starting at h of length bytes. - * Memory for the block is mapped. - * Remove the block from its free list, and return the remainder (if any) - * to its appropriate free list. - * May fail by returning 0. - * The header for the returned block must be set up by the caller. - * If the return value is not 0, then hhdr is the header for it. - */ -struct hblk * GC_get_first_part(h, hhdr, bytes, index) -struct hblk *h; -hdr * hhdr; -word bytes; -int index; -{ - word total_size = hhdr -> hb_sz; - struct hblk * rest; - hdr * rest_hdr; - - GC_ASSERT((total_size & (HBLKSIZE-1)) == 0); - GC_remove_from_fl(hhdr, index); - if (total_size == bytes) return h; - rest = (struct hblk *)((word)h + bytes); - rest_hdr = GC_install_header(rest); - if (0 == rest_hdr) return(0); - rest_hdr -> hb_sz = total_size - bytes; - rest_hdr -> hb_flags = 0; -# ifdef GC_ASSERTIONS - /* Mark h not free, to avoid assertion about adjacent free blocks. */ - hhdr -> hb_map = 0; -# endif - GC_add_to_fl(rest, rest_hdr); - return h; -} - -/* - * H is a free block. N points at an address inside it. - * A new header for n has already been set up. Fix up h's header - * to reflect the fact that it is being split, move it to the - * appropriate free list. - * N replaces h in the original free list. - * - * Nhdr is not completely filled in, since it is about to allocated. - * It may in fact end up on the wrong free list for its size. - * (Hence adding it to a free list is silly. But this path is hopefully - * rare enough that it doesn't matter. The code is cleaner this way.) - */ -void GC_split_block(h, hhdr, n, nhdr, index) -struct hblk *h; -hdr * hhdr; -struct hblk *n; -hdr * nhdr; -int index; /* Index of free list */ -{ - word total_size = hhdr -> hb_sz; - word h_size = (word)n - (word)h; - struct hblk *prev = hhdr -> hb_prev; - struct hblk *next = hhdr -> hb_next; - - /* Replace h with n on its freelist */ - nhdr -> hb_prev = prev; - nhdr -> hb_next = next; - nhdr -> hb_sz = total_size - h_size; - nhdr -> hb_flags = 0; - if (0 != prev) { - HDR(prev) -> hb_next = n; - } else { - GC_hblkfreelist[index] = n; - } - if (0 != next) { - HDR(next) -> hb_prev = n; - } - INCR_FREE_BYTES(index, -(signed_word)h_size); - FREE_ASSERT(GC_free_bytes[index] > 0); -# ifdef GC_ASSERTIONS - nhdr -> hb_map = 0; /* Don't fail test for consecutive */ - /* free blocks in GC_add_to_fl. */ -# endif -# ifdef USE_MUNMAP - hhdr -> hb_last_reclaimed = GC_gc_no; -# endif - hhdr -> hb_sz = h_size; - GC_add_to_fl(h, hhdr); - GC_invalidate_map(nhdr); -} - -struct hblk * GC_allochblk_nth(); - -/* - * Allocate (and return pointer to) a heap block - * for objects of size sz words, searching the nth free list. - * - * NOTE: We set obj_map field in header correctly. - * Caller is responsible for building an object freelist in block. - * - * Unlike older versions of the collectors, the client is responsible - * for clearing the block, if necessary. - */ -struct hblk * -GC_allochblk(sz, kind, flags) -word sz; -int kind; -unsigned flags; /* IGNORE_OFF_PAGE or 0 */ -{ - word blocks = OBJ_SZ_TO_BLOCKS(sz); - int start_list = GC_hblk_fl_from_blocks(blocks); - int i; - for (i = start_list; i <= N_HBLK_FLS; ++i) { - struct hblk * result = GC_allochblk_nth(sz, kind, flags, i); - if (0 != result) { - return result; - } - } - return 0; -} -/* - * The same, but with search restricted to nth free list. - */ -struct hblk * -GC_allochblk_nth(sz, kind, flags, n) -word sz; -int kind; -unsigned char flags; /* IGNORE_OFF_PAGE or 0 */ -int n; -{ - register struct hblk *hbp; - register hdr * hhdr; /* Header corr. to hbp */ - register struct hblk *thishbp; - register hdr * thishdr; /* Header corr. to hbp */ - signed_word size_needed; /* number of bytes in requested objects */ - signed_word size_avail; /* bytes available in this block */ - - size_needed = HBLKSIZE * OBJ_SZ_TO_BLOCKS(sz); - - /* search for a big enough block in free list */ - hbp = GC_hblkfreelist[n]; - for(; 0 != hbp; hbp = hhdr -> hb_next) { - GET_HDR(hbp, hhdr); - size_avail = hhdr->hb_sz; - if (size_avail < size_needed) continue; - if (!GC_use_entire_heap - && size_avail != size_needed - && USED_HEAP_SIZE >= GC_requested_heapsize - && !TRUE_INCREMENTAL && GC_should_collect()) { -# ifdef USE_MUNMAP - continue; -# else - /* If we have enough large blocks left to cover any */ - /* previous request for large blocks, we go ahead */ - /* and split. Assuming a steady state, that should */ - /* be safe. It means that we can use the full */ - /* heap if we allocate only small objects. */ - if (!GC_enough_large_bytes_left(GC_large_allocd_bytes, n)) { - continue; - } - /* If we are deallocating lots of memory from */ - /* finalizers, fail and collect sooner rather */ - /* than later. */ - if (GC_finalizer_mem_freed > (GC_heapsize >> 4)) { - continue; - } -# endif /* !USE_MUNMAP */ - } - /* If the next heap block is obviously better, go on. */ - /* This prevents us from disassembling a single large block */ - /* to get tiny blocks. */ - { - signed_word next_size; - - thishbp = hhdr -> hb_next; - if (thishbp != 0) { - GET_HDR(thishbp, thishdr); - next_size = (signed_word)(thishdr -> hb_sz); - if (next_size < size_avail - && next_size >= size_needed - && !GC_is_black_listed(thishbp, (word)size_needed)) { - continue; - } - } - } - if ( !IS_UNCOLLECTABLE(kind) && - (kind != PTRFREE || size_needed > MAX_BLACK_LIST_ALLOC)) { - struct hblk * lasthbp = hbp; - ptr_t search_end = (ptr_t)hbp + size_avail - size_needed; - signed_word orig_avail = size_avail; - signed_word eff_size_needed = ((flags & IGNORE_OFF_PAGE)? - HBLKSIZE - : size_needed); - - - while ((ptr_t)lasthbp <= search_end - && (thishbp = GC_is_black_listed(lasthbp, - (word)eff_size_needed)) - != 0) { - lasthbp = thishbp; - } - size_avail -= (ptr_t)lasthbp - (ptr_t)hbp; - thishbp = lasthbp; - if (size_avail >= size_needed) { - if (thishbp != hbp && - 0 != (thishdr = GC_install_header(thishbp))) { - /* Make sure it's mapped before we mangle it. */ -# ifdef USE_MUNMAP - if (!IS_MAPPED(hhdr)) { - GC_remap((ptr_t)hbp, hhdr -> hb_sz); - hhdr -> hb_flags &= ~WAS_UNMAPPED; - } -# endif - /* Split the block at thishbp */ - GC_split_block(hbp, hhdr, thishbp, thishdr, n); - /* Advance to thishbp */ - hbp = thishbp; - hhdr = thishdr; - /* We must now allocate thishbp, since it may */ - /* be on the wrong free list. */ - } - } else if (size_needed > (signed_word)BL_LIMIT - && orig_avail - size_needed - > (signed_word)BL_LIMIT) { - /* Punt, since anything else risks unreasonable heap growth. */ - if (++GC_large_alloc_warn_suppressed - >= GC_large_alloc_warn_interval) { - WARN("Repeated allocation of very large block " - "(appr. size %ld):\n" - "\tMay lead to memory leak and poor performance.\n", - size_needed); - GC_large_alloc_warn_suppressed = 0; - } - size_avail = orig_avail; - } else if (size_avail == 0 && size_needed == HBLKSIZE - && IS_MAPPED(hhdr)) { - if (!GC_find_leak) { - static unsigned count = 0; - - /* The block is completely blacklisted. We need */ - /* to drop some such blocks, since otherwise we spend */ - /* all our time traversing them if pointerfree */ - /* blocks are unpopular. */ - /* A dropped block will be reconsidered at next GC. */ - if ((++count & 3) == 0) { - /* Allocate and drop the block in small chunks, to */ - /* maximize the chance that we will recover some */ - /* later. */ - word total_size = hhdr -> hb_sz; - struct hblk * limit = hbp + divHBLKSZ(total_size); - struct hblk * h; - struct hblk * prev = hhdr -> hb_prev; - - GC_words_wasted += total_size; - GC_large_free_bytes -= total_size; - GC_remove_from_fl(hhdr, n); - for (h = hbp; h < limit; h++) { - if (h == hbp || 0 != (hhdr = GC_install_header(h))) { - (void) setup_header( - hhdr, - BYTES_TO_WORDS(HBLKSIZE), - PTRFREE, 0); /* Cant fail */ - if (GC_debugging_started) { - BZERO(h, HBLKSIZE); - } - } - } - /* Restore hbp to point at free block */ - hbp = prev; - if (0 == hbp) { - return GC_allochblk_nth(sz, kind, flags, n); - } - hhdr = HDR(hbp); - } - } - } - } - if( size_avail >= size_needed ) { -# ifdef USE_MUNMAP - if (!IS_MAPPED(hhdr)) { - GC_remap((ptr_t)hbp, hhdr -> hb_sz); - hhdr -> hb_flags &= ~WAS_UNMAPPED; - } -# endif - /* hbp may be on the wrong freelist; the parameter n */ - /* is important. */ - hbp = GC_get_first_part(hbp, hhdr, size_needed, n); - break; - } - } - - if (0 == hbp) return 0; - - /* Add it to map of valid blocks */ - if (!GC_install_counts(hbp, (word)size_needed)) return(0); - /* This leaks memory under very rare conditions. */ - - /* Set up header */ - if (!setup_header(hhdr, sz, kind, flags)) { - GC_remove_counts(hbp, (word)size_needed); - return(0); /* ditto */ - } - - /* Notify virtual dirty bit implementation that we are about to write. */ - /* Ensure that pointerfree objects are not protected if it's avoidable. */ - GC_remove_protection(hbp, divHBLKSZ(size_needed), - (hhdr -> hb_descr == 0) /* pointer-free */); - - /* We just successfully allocated a block. Restart count of */ - /* consecutive failures. */ - { - extern unsigned GC_fail_count; - - GC_fail_count = 0; - } - - GC_large_free_bytes -= size_needed; - - GC_ASSERT(IS_MAPPED(hhdr)); - return( hbp ); -} - -struct hblk * GC_freehblk_ptr = 0; /* Search position hint for GC_freehblk */ - -/* - * Free a heap block. - * - * Coalesce the block with its neighbors if possible. - * - * All mark words are assumed to be cleared. - */ -void -GC_freehblk(hbp) -struct hblk *hbp; -{ -struct hblk *next, *prev; -hdr *hhdr, *prevhdr, *nexthdr; -signed_word size; - - - GET_HDR(hbp, hhdr); - size = hhdr->hb_sz; - size = HBLKSIZE * OBJ_SZ_TO_BLOCKS(size); - GC_remove_counts(hbp, (word)size); - hhdr->hb_sz = size; - - /* Check for duplicate deallocation in the easy case */ - if (HBLK_IS_FREE(hhdr)) { - GC_printf1("Duplicate large block deallocation of 0x%lx\n", - (unsigned long) hbp); - ABORT("Duplicate large block deallocation"); - } - - GC_ASSERT(IS_MAPPED(hhdr)); - GC_invalidate_map(hhdr); - next = (struct hblk *)((word)hbp + size); - GET_HDR(next, nexthdr); - prev = GC_free_block_ending_at(hbp); - /* Coalesce with successor, if possible */ - if(0 != nexthdr && HBLK_IS_FREE(nexthdr) && IS_MAPPED(nexthdr)) { - GC_remove_from_fl(nexthdr, FL_UNKNOWN); - hhdr -> hb_sz += nexthdr -> hb_sz; - GC_remove_header(next); - } - /* Coalesce with predecessor, if possible. */ - if (0 != prev) { - prevhdr = HDR(prev); - if (IS_MAPPED(prevhdr)) { - GC_remove_from_fl(prevhdr, FL_UNKNOWN); - prevhdr -> hb_sz += hhdr -> hb_sz; - GC_remove_header(hbp); - hbp = prev; - hhdr = prevhdr; - } - } - - GC_large_free_bytes += size; - GC_add_to_fl(hbp, hhdr); -} - |