76 lines
2.3 KiB
C
76 lines
2.3 KiB
C
/* slab.h
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* Definitions for very simple slab handling
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef __SLAB_H__
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#define __SLAB_H__
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#define NITEMS_PER_SLAB 100
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/*
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* Generate declaration of a union type containing the specified type of
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* slab-allocated item, and a pointer to an object of that type, for use
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* in the macros below.
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*/
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#define SLAB_ITEM_TYPE_DEFINE(type) \
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union type ## slab_item { \
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type slab_item; \
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union type ## slab_item *next_free; \
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};
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/*
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* Generate definition of the free list pointer.
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*/
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#define SLAB_FREE_LIST_DEFINE(type) \
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union type ## slab_item *type ## _free_list = NULL;
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/*
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* Generate an external declaration of the free list pointer.
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*/
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#define SLAB_FREE_LIST_DECLARE(type) \
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union type ## slab_item *type ## _free_list;
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/* we never free any memory we have allocated, when it is returned to us
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we just store it in the free list until (hopefully) it gets used again
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*/
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#define SLAB_ALLOC(item, type) \
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if(!type ## _free_list){ \
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int i; \
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union type ## slab_item *tmp; \
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tmp=g_malloc(NITEMS_PER_SLAB*sizeof(*tmp)); \
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for(i=0;i<NITEMS_PER_SLAB;i++){ \
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tmp[i].next_free = type ## _free_list; \
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type ## _free_list = &tmp[i]; \
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} \
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} \
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item = &(type ## _free_list->slab_item); \
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type ## _free_list = type ## _free_list->next_free;
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#define SLAB_FREE(item, type) \
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{ \
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((union type ## slab_item *)(void *)item)->next_free = type ## _free_list; \
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type ## _free_list = (union type ## slab_item *)(void *)item; \
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}
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#endif /* slab.h */
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