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/* wmem_allocator_simple.c
* Wireshark Memory Manager Simple Allocator
* Copyright 2012, Evan Huus <eapache@gmail.com>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <string.h>
#include <glib.h>
#include "wmem_core.h"
#include "wmem_allocator.h"
#include "wmem_allocator_simple.h"
/* In this trivial allocator, we just store a GHashTable of malloc()ed
* blocks in the private_data pointer. We could just set the private_data
* pointer directly to the GHashTable, but we use a separate structure here
* to demonstrate the pattern that most other allocators should follow. */
typedef struct _wmem_simple_allocator_t {
GHashTable *block_table;
} wmem_simple_allocator_t;
static void *
wmem_simple_alloc(void *private_data, const size_t size)
{
void *buf;
wmem_simple_allocator_t *allocator;
allocator = (wmem_simple_allocator_t*) private_data;
buf = wmem_alloc(NULL, size);
g_hash_table_insert(allocator->block_table, buf, buf);
return buf;
}
static void
wmem_simple_do_free(gpointer ptr)
{
wmem_free(NULL, ptr);
}
static void
wmem_simple_free(void *private_data, void *ptr)
{
gboolean removed;
wmem_simple_allocator_t *allocator;
allocator = (wmem_simple_allocator_t*) private_data;
/* remove() takes care of calling wmem_free() for us since we set up the
* hash table with g_hash_table_new_full() */
removed = g_hash_table_remove(allocator->block_table, ptr);
g_assert(removed);
}
static void *
wmem_simple_realloc(void *private_data, void *ptr, const size_t size)
{ void *newptr;
wmem_simple_allocator_t *allocator;
allocator = (wmem_simple_allocator_t*) private_data;
newptr = wmem_realloc(NULL, ptr, size);
if (ptr != newptr) {
/* Realloc actually moved the memory block, so we need to replace the
* value in our hash table. Calling g_hash_table_remove() would trigger
* a wmem_free() which is incorrect since realloc already reclaimed the old
* block, so use g_hash_table_steal() instead. */
g_hash_table_steal(allocator->block_table, ptr);
g_hash_table_insert(allocator->block_table, newptr, newptr);
}
return newptr;
}
static void
wmem_simple_free_all(void *private_data)
{
wmem_simple_allocator_t *allocator;
allocator = (wmem_simple_allocator_t*) private_data;
/* remove_all() takes care of calling wmem_free() for us since we set up the
* hash table with g_hash_table_new_full() */
g_hash_table_remove_all(allocator->block_table);
}
static void
wmem_simple_gc(void *private_data _U_)
{
/* In this simple allocator, there is nothing to garbage-collect */
}
static void
wmem_simple_allocator_cleanup(void *private_data)
{
wmem_simple_allocator_t *allocator;
allocator = (wmem_simple_allocator_t*) private_data;
g_hash_table_destroy(allocator->block_table);
wmem_free(NULL, allocator);
}
void
wmem_simple_allocator_init(wmem_allocator_t *allocator)
{
wmem_simple_allocator_t *simple_allocator;
simple_allocator = wmem_new(NULL, wmem_simple_allocator_t);
allocator->alloc = &wmem_simple_alloc;
allocator->realloc = &wmem_simple_realloc;
allocator->free = &wmem_simple_free;
allocator->free_all = &wmem_simple_free_all;
allocator->gc = &wmem_simple_gc;
allocator->cleanup = &wmem_simple_allocator_cleanup;
allocator->private_data = (void*) simple_allocator;
simple_allocator->block_table = g_hash_table_new_full(
&g_direct_hash, &g_direct_equal, NULL, &wmem_simple_do_free);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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