remove gc

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);    
-}
-