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authorKevin Ryde <user42@zip.com.au>2001-10-11 02:21:53 +0200
committerKevin Ryde <user42@zip.com.au>2001-10-11 02:21:53 +0200
commit541d3770811f229adb907ac44cc9d87ed9632d8d (patch)
tree3f763b34f04f27f82e7a1d8bac3ac1d7516ab4b6 /tal-notreent.c
parentb38bcbfa819d5f46259b583e45bc883ecebc0ef7 (diff)
downloadgmp-541d3770811f229adb907ac44cc9d87ed9632d8d.tar.gz
Amend to:
* tal-notreent.c: Renamed from stack-alloc.c.
Diffstat (limited to 'tal-notreent.c')
-rw-r--r--tal-notreent.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/tal-notreent.c b/tal-notreent.c
new file mode 100644
index 000000000..fb456a1ec
--- /dev/null
+++ b/tal-notreent.c
@@ -0,0 +1,121 @@
+/* Stack allocation routines. This is intended for machines without support
+ for the `alloca' function.
+
+Copyright 1996, 1997, 1999, 2000, 2001 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MP 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP 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. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+
+struct tmp_stack
+{
+ void *end;
+ void *alloc_point;
+ struct tmp_stack *prev;
+};
+typedef struct tmp_stack tmp_stack;
+
+
+static unsigned long max_total_allocation = 0;
+static unsigned long current_total_allocation = 0;
+
+static tmp_stack xxx = {&xxx, &xxx, 0};
+static tmp_stack *current = &xxx;
+
+/* The rounded size of the header of each allocation block. */
+#define HSIZ ROUND_UP_MULTIPLE (sizeof (tmp_stack), __TMP_ALIGN)
+
+
+/* Allocate a block of exactly <size> bytes. This should only be called
+ through the TMP_ALLOC macro, which takes care of rounding/alignment. */
+void *
+__gmp_tmp_alloc (unsigned long size)
+{
+ void *that;
+
+ ASSERT ((size % __TMP_ALIGN) == 0);
+ ASSERT (((unsigned) current->alloc_point % __TMP_ALIGN) == 0);
+
+ if (size > (char *) current->end - (char *) current->alloc_point)
+ {
+ void *chunk;
+ tmp_stack *header;
+ unsigned long chunk_size;
+ unsigned long now;
+
+ /* Allocate a chunk that makes the total current allocation somewhat
+ larger than the maximum allocation ever. If size is very large, we
+ allocate that much. */
+
+ now = current_total_allocation + size;
+ if (now > max_total_allocation)
+ {
+ /* We need more temporary memory than ever before. Increase
+ for future needs. */
+ now = (now * 3 / 2 + __TMP_ALIGN - 1) & -__TMP_ALIGN;
+ chunk_size = now - current_total_allocation + HSIZ;
+ current_total_allocation = now;
+ max_total_allocation = current_total_allocation;
+ }
+ else
+ {
+ chunk_size = max_total_allocation - current_total_allocation + HSIZ;
+ current_total_allocation = max_total_allocation;
+ }
+
+ chunk = (*__gmp_allocate_func) (chunk_size);
+ header = (tmp_stack *) chunk;
+ header->end = (char *) chunk + chunk_size;
+ header->alloc_point = (char *) chunk + HSIZ;
+ header->prev = current;
+ current = header;
+ }
+
+ that = current->alloc_point;
+ current->alloc_point = (char *) that + size;
+ ASSERT (((unsigned) that % __TMP_ALIGN) == 0);
+ return that;
+}
+
+/* Typically called at function entry. <mark> is assigned so that
+ __gmp_tmp_free can later be used to reclaim all subsequently allocated
+ storage. */
+void
+__gmp_tmp_mark (tmp_marker *mark)
+{
+ mark->which_chunk = current;
+ mark->alloc_point = current->alloc_point;
+}
+
+/* Free everything allocated since <mark> was assigned by __gmp_tmp_mark */
+void
+__gmp_tmp_free (tmp_marker *mark)
+{
+ while (mark->which_chunk != current)
+ {
+ tmp_stack *tmp;
+
+ tmp = current;
+ current = tmp->prev;
+ current_total_allocation -= (((char *) (tmp->end) - (char *) tmp) - HSIZ);
+ (*__gmp_free_func) (tmp, (char *) tmp->end - (char *) tmp);
+ }
+ current->alloc_point = mark->alloc_point;
+}