2 files changed, 306 insertions, 2 deletions

diff --git a/gnu/lib/libmalloc/Makefile b/gnu/lib/libmalloc/Makefile
index b5aeb2606f31..463927d29b6b 100644
--- a/gnu/lib/libmalloc/Makefile
+++ b/gnu/lib/libmalloc/Makefile
@@ -1,9 +1,9 @@
-#	$Id: Makefile,v 1.1 1993/09/23 21:10:40 cgd Exp $
+#	$Id: Makefile,v 1.1 1993/09/24 13:03:14 rgrimes Exp $
 
 CFLAGS+= -I${.CURDIR}
 
 LIB=	gnumalloc
-SRCS+=	malloc.c free.c cfree.c realloc.c calloc.c morecore.c
+SRCS+=	malloc.c cfree.c calloc.c morecore.c
 SRCS+=	memalign.c valloc.c mcheck.c mtrace.c mstats.c vm-limit.c
 SRCS+=	ralloc.c
 NOMAN=	noman
diff --git a/gnu/lib/libmalloc/malloc.c b/gnu/lib/libmalloc/malloc.c
index 47a6b8d46e54..3c1ee9943d57 100644
--- a/gnu/lib/libmalloc/malloc.c
+++ b/gnu/lib/libmalloc/malloc.c
@@ -316,3 +316,307 @@ malloc (size)
 
   return result;
 }
+
+#define min(A, B) ((A) < (B) ? (A) : (B))
+
+/* Debugging hook for realloc.  */
+__ptr_t (*__realloc_hook) __P ((__ptr_t __ptr, size_t __size));
+
+/* Resize the given region to the new size, returning a pointer
+   to the (possibly moved) region.  This is optimized for speed;
+   some benchmarks seem to indicate that greater compactness is
+   achieved by unconditionally allocating and copying to a
+   new region.  This module has incestuous knowledge of the
+   internals of both free and malloc. */
+__ptr_t
+realloc (ptr, size)
+     __ptr_t ptr;
+     size_t size;
+{
+  __ptr_t result;
+  int type;
+  size_t block, blocks, oldlimit;
+
+  if (size == 0)
+    {
+      free (ptr);
+      return malloc (0);
+    }
+  else if (ptr == NULL)
+    return malloc (size);
+
+  if (__realloc_hook != NULL)
+    return (*__realloc_hook) (ptr, size);
+
+  block = BLOCK (ptr);
+
+  type = _heapinfo[block].busy.type;
+  switch (type)
+    {
+    case 0:
+      /* Maybe reallocate a large block to a small fragment.  */
+      if (size <= BLOCKSIZE / 2)
+	{
+	  result = malloc (size);
+	  if (result != NULL)
+	    {
+	      memcpy (result, ptr, size);
+	      free (ptr);
+	      return result;
+	    }
+	}
+
+      /* The new size is a large allocation as well;
+	 see if we can hold it in place. */
+      blocks = BLOCKIFY (size);
+      if (blocks < _heapinfo[block].busy.info.size)
+	{
+	  /* The new size is smaller; return
+	     excess memory to the free list. */
+	  _heapinfo[block + blocks].busy.type = 0;
+	  _heapinfo[block + blocks].busy.info.size
+	    = _heapinfo[block].busy.info.size - blocks;
+	  _heapinfo[block].busy.info.size = blocks;
+	  free (ADDRESS (block + blocks));
+	  result = ptr;
+	}
+      else if (blocks == _heapinfo[block].busy.info.size)
+	/* No size change necessary.  */
+	result = ptr;
+      else
+	{
+	  /* Won't fit, so allocate a new region that will.
+	     Free the old region first in case there is sufficient
+	     adjacent free space to grow without moving. */
+	  blocks = _heapinfo[block].busy.info.size;
+	  /* Prevent free from actually returning memory to the system.  */
+	  oldlimit = _heaplimit;
+	  _heaplimit = 0;
+	  free (ptr);
+	  _heaplimit = oldlimit;
+	  result = malloc (size);
+	  if (result == NULL)
+	    {
+	      /* Now we're really in trouble.  We have to unfree
+		 the thing we just freed.  Unfortunately it might
+		 have been coalesced with its neighbors.  */
+	      if (_heapindex == block)
+	        (void) malloc (blocks * BLOCKSIZE);
+	      else
+		{
+		  __ptr_t previous = malloc ((block - _heapindex) * BLOCKSIZE);
+		  (void) malloc (blocks * BLOCKSIZE);
+		  free (previous);
+		}
+	      return NULL;
+	    }
+	  if (ptr != result)
+	    memmove (result, ptr, blocks * BLOCKSIZE);
+	}
+      break;
+
+    default:
+      /* Old size is a fragment; type is logarithm
+	 to base two of the fragment size.  */
+      if (size > (size_t) (1 << (type - 1)) && size <= (size_t) (1 << type))
+	/* The new size is the same kind of fragment.  */
+	result = ptr;
+      else
+	{
+	  /* The new size is different; allocate a new space,
+	     and copy the lesser of the new size and the old. */
+	  result = malloc (size);
+	  if (result == NULL)
+	    return NULL;
+	  memcpy (result, ptr, min (size, (size_t) 1 << type));
+	  free (ptr);
+	}
+      break;
+    }
+
+  return result;
+}
+
+/* Debugging hook for free.  */
+void (*__free_hook) __P ((__ptr_t __ptr));
+
+/* List of blocks allocated by memalign.  */
+struct alignlist *_aligned_blocks = NULL;
+
+/* Return memory to the heap.
+   Like `free' but don't call a __free_hook if there is one.  */
+void
+_free_internal (ptr)
+     __ptr_t ptr;
+{
+  int type;
+  size_t block, blocks;
+  register size_t i;
+  struct list *prev, *next;
+
+  block = BLOCK (ptr);
+
+  type = _heapinfo[block].busy.type;
+  switch (type)
+    {
+    case 0:
+      /* Get as many statistics as early as we can.  */
+      --_chunks_used;
+      _bytes_used -= _heapinfo[block].busy.info.size * BLOCKSIZE;
+      _bytes_free += _heapinfo[block].busy.info.size * BLOCKSIZE;
+
+      /* Find the free cluster previous to this one in the free list.
+	 Start searching at the last block referenced; this may benefit
+	 programs with locality of allocation.  */
+      i = _heapindex;
+      if (i > block)
+	while (i > block)
+	  i = _heapinfo[i].free.prev;
+      else
+	{
+	  do
+	    i = _heapinfo[i].free.next;
+	  while (i > 0 && i < block);
+	  i = _heapinfo[i].free.prev;
+	}
+
+      /* Determine how to link this block into the free list.  */
+      if (block == i + _heapinfo[i].free.size)
+	{
+	  /* Coalesce this block with its predecessor.  */
+	  _heapinfo[i].free.size += _heapinfo[block].busy.info.size;
+	  block = i;
+	}
+      else
+	{
+	  /* Really link this block back into the free list.  */
+	  _heapinfo[block].free.size = _heapinfo[block].busy.info.size;
+	  _heapinfo[block].free.next = _heapinfo[i].free.next;
+	  _heapinfo[block].free.prev = i;
+	  _heapinfo[i].free.next = block;
+	  _heapinfo[_heapinfo[block].free.next].free.prev = block;
+	  ++_chunks_free;
+	}
+
+      /* Now that the block is linked in, see if we can coalesce it
+	 with its successor (by deleting its successor from the list
+	 and adding in its size).  */
+      if (block + _heapinfo[block].free.size == _heapinfo[block].free.next)
+	{
+	  _heapinfo[block].free.size
+	    += _heapinfo[_heapinfo[block].free.next].free.size;
+	  _heapinfo[block].free.next
+	    = _heapinfo[_heapinfo[block].free.next].free.next;
+	  _heapinfo[_heapinfo[block].free.next].free.prev = block;
+	  --_chunks_free;
+	}
+
+      /* Now see if we can return stuff to the system.  */
+      blocks = _heapinfo[block].free.size;
+      if (blocks >= FINAL_FREE_BLOCKS && block + blocks == _heaplimit
+	  && (*__morecore) (0) == ADDRESS (block + blocks))
+	{
+	  register size_t bytes = blocks * BLOCKSIZE;
+	  _heaplimit -= blocks;
+	  (*__morecore) (-bytes);
+	  _heapinfo[_heapinfo[block].free.prev].free.next
+	    = _heapinfo[block].free.next;
+	  _heapinfo[_heapinfo[block].free.next].free.prev
+	    = _heapinfo[block].free.prev;
+	  block = _heapinfo[block].free.prev;
+	  --_chunks_free;
+	  _bytes_free -= bytes;
+	}
+
+      /* Set the next search to begin at this block.  */
+      _heapindex = block;
+      break;
+
+    default:
+      /* Do some of the statistics.  */
+      --_chunks_used;
+      _bytes_used -= 1 << type;
+      ++_chunks_free;
+      _bytes_free += 1 << type;
+
+      /* Get the address of the first free fragment in this block.  */
+      prev = (struct list *) ((char *) ADDRESS (block) +
+			   (_heapinfo[block].busy.info.frag.first << type));
+
+      if (_heapinfo[block].busy.info.frag.nfree == (BLOCKSIZE >> type) - 1)
+	{
+	  /* If all fragments of this block are free, remove them
+	     from the fragment list and free the whole block.  */
+	  next = prev;
+	  for (i = 1; i < (size_t) (BLOCKSIZE >> type); ++i)
+	    next = next->next;
+	  prev->prev->next = next;
+	  if (next != NULL)
+	    next->prev = prev->prev;
+	  _heapinfo[block].busy.type = 0;
+	  _heapinfo[block].busy.info.size = 1;
+
+	  /* Keep the statistics accurate.  */
+	  ++_chunks_used;
+	  _bytes_used += BLOCKSIZE;
+	  _chunks_free -= BLOCKSIZE >> type;
+	  _bytes_free -= BLOCKSIZE;
+
+	  free (ADDRESS (block));
+	}
+      else if (_heapinfo[block].busy.info.frag.nfree != 0)
+	{
+	  /* If some fragments of this block are free, link this
+	     fragment into the fragment list after the first free
+	     fragment of this block. */
+	  next = (struct list *) ptr;
+	  next->next = prev->next;
+	  next->prev = prev;
+	  prev->next = next;
+	  if (next->next != NULL)
+	    next->next->prev = next;
+	  ++_heapinfo[block].busy.info.frag.nfree;
+	}
+      else
+	{
+	  /* No fragments of this block are free, so link this
+	     fragment into the fragment list and announce that
+	     it is the first free fragment of this block. */
+	  prev = (struct list *) ptr;
+	  _heapinfo[block].busy.info.frag.nfree = 1;
+	  _heapinfo[block].busy.info.frag.first = (unsigned long int)
+	    ((unsigned long int) ((char *) ptr - (char *) NULL)
+	     % BLOCKSIZE >> type);
+	  prev->next = _fraghead[type].next;
+	  prev->prev = &_fraghead[type];
+	  prev->prev->next = prev;
+	  if (prev->next != NULL)
+	    prev->next->prev = prev;
+	}
+      break;
+    }
+}
+
+/* Return memory to the heap.  */
+void
+free (ptr)
+     __ptr_t ptr;
+{
+  register struct alignlist *l;
+
+  if (ptr == NULL)
+    return;
+
+  for (l = _aligned_blocks; l != NULL; l = l->next)
+    if (l->aligned == ptr)
+      {
+	l->aligned = NULL;	/* Mark the slot in the list as free.  */
+	ptr = l->exact;
+	break;
+      }
+
+  if (__free_hook != NULL)
+    (*__free_hook) (ptr);
+  else
+    _free_internal (ptr);
+}