freelist.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
#ifndef freelist_h
#define freelist_h
/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004 by Martin C. Shepherd.
*
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, and/or sell copies of the Software, and to permit persons
* to whom the Software is furnished to do so, provided that the above
* copyright notice(s) and this permission notice appear in all copies of
* the Software and that both the above copyright notice(s) and this
* permission notice appear in supporting documentation.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
* OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
* INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Except as contained in this notice, the name of a copyright holder
* shall not be used in advertising or otherwise to promote the sale, use
* or other dealings in this Software without prior written authorization
* of the copyright holder.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* This module provides a memory allocation scheme that helps to
* prevent memory fragmentation by allocating large blocks of
* fixed sized objects and forming them into a free-list for
* subsequent allocations. The free-list is expanded as needed.
*/
typedef struct FreeList FreeList;
/*
* Allocate a new free-list from blocks of 'blocking_factor' objects of size
* node_size. The node_size argument should be determined by applying
* the sizeof() operator to the object type that you intend to allocate from
* the freelist.
*/
FreeList *_new_FreeList(size_t node_size, unsigned blocking_factor);
/*
* If it is known that none of the nodes currently allocated from
* a freelist are still in use, the following function can be called
* to return all nodes to the freelist without the overhead of
* having to call del_FreeListNode() for every allocated node. The
* nodes of the freelist can then be reused by future callers to
* new_FreeListNode().
*/
void _rst_FreeList(FreeList *fl);
/*
* Delete a free-list.
*/
FreeList *_del_FreeList(FreeList *fl, int force);
/*
* Determine the number of nodes that are currently in use.
*/
long _busy_FreeListNodes(FreeList *fl);
/*
* Query the number of allocated nodes in the freelist which are
* currently unused.
*/
long _idle_FreeListNodes(FreeList *fl);
/*
* Allocate a new object from a free-list.
*/
void *_new_FreeListNode(FreeList *fl);
/*
* Return an object to the free-list that it was allocated from.
*/
void *_del_FreeListNode(FreeList *fl, void *object);
#endif