--- /dev/null
+/* Free a block of memory allocated by `mmalloc'.
+ Copyright 1990, 1991, 1992 Free Software Foundation
+
+ Written May 1989 by Mike Haertel.
+ Heavily modified Mar 1992 by Fred Fish. (fnf@cygnus.com)
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.
+
+ The author may be reached (Email) at the address mike@ai.mit.edu,
+ or (US mail) as Mike Haertel c/o Free Software Foundation. */
+
+#include "mmprivate.h"
+
+/* Return memory to the heap.
+ Like `mfree' but don't call a mfree_hook if there is one. */
+
+void
+__mmalloc_free (mdp, ptr)
+ struct mdesc *mdp;
+ PTR ptr;
+{
+ int type;
+ size_t block, blocks;
+ register size_t i;
+ struct list *prev, *next;
+
+ block = BLOCK (ptr);
+
+ type = mdp -> heapinfo[block].busy.type;
+ switch (type)
+ {
+ case 0:
+ /* Get as many statistics as early as we can. */
+ mdp -> heapstats.chunks_used--;
+ mdp -> heapstats.bytes_used -=
+ mdp -> heapinfo[block].busy.info.size * BLOCKSIZE;
+ mdp -> heapstats.bytes_free +=
+ mdp -> 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 = mdp -> heapindex;
+ if (i > block)
+ {
+ while (i > block)
+ {
+ i = mdp -> heapinfo[i].free.prev;
+ }
+ }
+ else
+ {
+ do
+ {
+ i = mdp -> heapinfo[i].free.next;
+ }
+ while ((i != 0) && (i < block));
+ i = mdp -> heapinfo[i].free.prev;
+ }
+
+ /* Determine how to link this block into the free list. */
+ if (block == i + mdp -> heapinfo[i].free.size)
+ {
+ /* Coalesce this block with its predecessor. */
+ mdp -> heapinfo[i].free.size +=
+ mdp -> heapinfo[block].busy.info.size;
+ block = i;
+ }
+ else
+ {
+ /* Really link this block back into the free list. */
+ mdp -> heapinfo[block].free.size =
+ mdp -> heapinfo[block].busy.info.size;
+ mdp -> heapinfo[block].free.next = mdp -> heapinfo[i].free.next;
+ mdp -> heapinfo[block].free.prev = i;
+ mdp -> heapinfo[i].free.next = block;
+ mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev = block;
+ mdp -> heapstats.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 + mdp -> heapinfo[block].free.size ==
+ mdp -> heapinfo[block].free.next)
+ {
+ mdp -> heapinfo[block].free.size
+ += mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.size;
+ mdp -> heapinfo[block].free.next
+ = mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.next;
+ mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev = block;
+ mdp -> heapstats.chunks_free--;
+ }
+
+ /* Now see if we can return stuff to the system. */
+ blocks = mdp -> heapinfo[block].free.size;
+ if (blocks >= FINAL_FREE_BLOCKS && block + blocks == mdp -> heaplimit
+ && mdp -> morecore (mdp, 0) == ADDRESS (block + blocks))
+ {
+ register size_t bytes = blocks * BLOCKSIZE;
+ mdp -> heaplimit -= blocks;
+ mdp -> morecore (mdp, -bytes);
+ mdp -> heapinfo[mdp -> heapinfo[block].free.prev].free.next
+ = mdp -> heapinfo[block].free.next;
+ mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev
+ = mdp -> heapinfo[block].free.prev;
+ block = mdp -> heapinfo[block].free.prev;
+ mdp -> heapstats.chunks_free--;
+ mdp -> heapstats.bytes_free -= bytes;
+ }
+
+ /* Set the next search to begin at this block. */
+ mdp -> heapindex = block;
+ break;
+
+ default:
+ /* Do some of the statistics. */
+ mdp -> heapstats.chunks_used--;
+ mdp -> heapstats.bytes_used -= 1 << type;
+ mdp -> heapstats.chunks_free++;
+ mdp -> heapstats.bytes_free += 1 << type;
+
+ /* Get the address of the first free fragment in this block. */
+ prev = (struct list *)
+ ((char *) ADDRESS(block) +
+ (mdp -> heapinfo[block].busy.info.frag.first << type));
+
+ if (mdp -> 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;
+ }
+ mdp -> heapinfo[block].busy.type = 0;
+ mdp -> heapinfo[block].busy.info.size = 1;
+
+ /* Keep the statistics accurate. */
+ mdp -> heapstats.chunks_used++;
+ mdp -> heapstats.bytes_used += BLOCKSIZE;
+ mdp -> heapstats.chunks_free -= BLOCKSIZE >> type;
+ mdp -> heapstats.bytes_free -= BLOCKSIZE;
+
+ mfree ((PTR) mdp, (PTR) ADDRESS(block));
+ }
+ else if (mdp -> 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;
+ }
+ ++mdp -> 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;
+ mdp -> heapinfo[block].busy.info.frag.nfree = 1;
+ mdp -> heapinfo[block].busy.info.frag.first =
+ RESIDUAL (ptr, BLOCKSIZE) >> type;
+ prev -> next = mdp -> fraghead[type].next;
+ prev -> prev = &mdp -> fraghead[type];
+ prev -> prev -> next = prev;
+ if (prev -> next != NULL)
+ {
+ prev -> next -> prev = prev;
+ }
+ }
+ break;
+ }
+}
+
+/* Return memory to the heap. */
+
+void
+mfree (md, ptr)
+ PTR md;
+ PTR ptr;
+{
+ struct mdesc *mdp;
+ register struct alignlist *l;
+
+ if (ptr != NULL)
+ {
+ mdp = MD_TO_MDP (md);
+ for (l = mdp -> 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 (mdp -> mfree_hook != NULL)
+ {
+ (*mdp -> mfree_hook) (md, ptr);
+ }
+ else
+ {
+ __mmalloc_free (mdp, ptr);
+ }
+ }
+}
+
+/* When using this package, provide a version of malloc/realloc/free built
+ on top of it, so that if we use the default sbrk() region we will not
+ collide with another malloc package trying to do the same thing, if
+ the application contains any "hidden" calls to malloc/realloc/free (such
+ as inside a system library). */
+
+void
+free (ptr)
+ PTR ptr;
+{
+ mfree ((PTR) NULL, ptr);
+}
git.annexia.org / ocaml-ancient.git / blobdiff