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/* 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 "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++;
}
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