2002-12-18 Daniel Berlin <dberlin@dberlin.org>

	* Makefile.in (OBJS): Add alloc-pool.o
	(alloc-pool.o): New object.

	* alloc-pool.c: New file.
	* alloc-pool.h: New file.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@60312 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 166 insertions, 0 deletions

diff --git a/gcc/alloc-pool.c b/gcc/alloc-pool.c
new file mode 100644
index 00000000000..b84780aec1c
--- /dev/null
+++ b/gcc/alloc-pool.c
@@ -0,0 +1,166 @@
+/* Functions to support a pool of allocatable objects.
+   Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Contributed by Daniel Berlin <dan@cgsoftware.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+GCC 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 General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+#include "libiberty.h"
+#include "config.h"
+#include "system.h"
+#include "alloc-pool.h"
+
+#define align_four(x) (((x+3) >> 2) << 2)
+#define align_eight(x) (((x+7) >> 3) << 3)
+
+/* Create a pool of things of size SIZE, with NUM in each block we
+   allocate.  */
+
+alloc_pool
+create_alloc_pool (name, size, num)
+     const char *name;
+     size_t size;
+     size_t num;
+{
+  alloc_pool pool;
+  size_t pool_size, header_size;
+
+  if (!name)
+    abort ();
+
+  /* Make size large enough to store the list header.  */
+  if (size < sizeof (alloc_pool_list))
+    size = sizeof (alloc_pool_list);
+
+  /* Now align the size to a multiple of 4.  */
+  size = align_four (size);
+
+  /* Um, we can't really allocate 0 elements per block.  */
+  if (num == 0)
+    abort ();
+
+  /* Find the size of the pool structure, and the name.  */
+  pool_size = sizeof (struct alloc_pool_def);
+
+  /* and allocate that much memory.  */
+  pool = (alloc_pool) xmalloc (pool_size);
+
+  /* Now init the various pieces of our pool structure.  */
+  pool->name = xstrdup (name);
+  pool->elt_size = size;
+  pool->elts_per_block = num;
+
+  /* List header size should be a multiple of 8 */
+  header_size = align_eight (sizeof (struct alloc_pool_list_def));
+
+  pool->block_size = (size * num) + header_size;
+  pool->free_list = NULL;
+  pool->elts_allocated = 0;
+  pool->elts_free = 0;
+  pool->blocks_allocated = 0;
+  pool->block_list = NULL;
+
+  return (pool);
+}
+
+/* Free all memory allocated for the given memory pool.  */
+void
+free_alloc_pool (pool)
+     alloc_pool pool;
+{
+  alloc_pool_list block, next_block;
+
+  if (!pool)
+    abort ();
+
+  /* Free each block allocated to the pool.  */
+  for (block = pool->block_list; block != NULL; block = next_block)
+    {
+      next_block = block->next;
+      free (block);
+    }
+  /* Lastly, free the pool and the name.  */
+  free (pool->name);
+  free (pool);
+}
+
+/* Allocates one element from the pool specified.  */
+void *
+pool_alloc (pool)
+     alloc_pool pool;
+{
+  alloc_pool_list header;
+  char *block;
+
+  if (!pool)
+    abort ();
+
+  /* If there are no more free elements, make some more!.  */
+  if (!pool->free_list)
+    {
+      size_t i;
+      alloc_pool_list block_header;
+
+      /* Make the block */
+      block = (char *) xmalloc (pool->block_size);
+      block_header = (alloc_pool_list) block;
+      block += align_eight (sizeof (struct alloc_pool_list_def));
+
+      /* Throw it on the block list */
+      block_header->next = pool->block_list;
+      pool->block_list = block_header;
+
+      /* Now put the actual block pieces onto the free list.  */
+      for (i = 0; i < pool->elts_per_block; i++, block += pool->elt_size)
+      {
+        header = (alloc_pool_list) block;
+        header->next = pool->free_list;
+        pool->free_list = header;
+      }
+      /* Also update the number of elements we have free/allocated, and
+         increment the allocated block count.  */
+      pool->elts_allocated += pool->elts_per_block;
+      pool->elts_free += pool->elts_per_block;
+      pool->blocks_allocated += 1;
+    }
+
+  /* Pull the first free element from the free list, and return it.  */
+  header = pool->free_list;
+  pool->free_list = header->next;
+  pool->elts_free--;
+  return ((void *) header);
+}
+
+/* Puts PTR back on POOL's free list.  */
+void
+pool_free (pool, ptr)
+     alloc_pool pool;
+     void *ptr;
+{
+  alloc_pool_list header;
+
+  if (!ptr)
+    abort ();
+
+  /* Check if we free more than we allocated, which is Bad (TM).  */
+  if (pool->elts_free + 1 > pool->elts_allocated)
+    abort ();
+  header = (alloc_pool_list) ptr;
+  header->next = pool->free_list;
+  pool->free_list = header;
+  pool->elts_free++;
+}