1 #ifndef freelist_h 2 #define freelist_h 3 4 /* 5 * Copyright (c) 2000, 2001, 2002, 2003, 2004 by Martin C. Shepherd. 6 * 7 * All rights reserved. 8 * 9 * Permission is hereby granted, free of charge, to any person obtaining a 10 * copy of this software and associated documentation files (the 11 * "Software"), to deal in the Software without restriction, including 12 * without limitation the rights to use, copy, modify, merge, publish, 13 * distribute, and/or sell copies of the Software, and to permit persons 14 * to whom the Software is furnished to do so, provided that the above 15 * copyright notice(s) and this permission notice appear in all copies of 16 * the Software and that both the above copyright notice(s) and this 17 * permission notice appear in supporting documentation. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT 22 * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 23 * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL 24 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING 25 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, 26 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 27 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 28 * 29 * Except as contained in this notice, the name of a copyright holder 30 * shall not be used in advertising or otherwise to promote the sale, use 31 * or other dealings in this Software without prior written authorization 32 * of the copyright holder. 33 */ 34 35 #pragma ident "%Z%%M% %I% %E% SMI" 36 37 /* 38 * This module provides a memory allocation scheme that helps to 39 * prevent memory fragmentation by allocating large blocks of 40 * fixed sized objects and forming them into a free-list for 41 * subsequent allocations. The free-list is expanded as needed. 42 */ 43 typedef struct FreeList FreeList; 44 45 /* 46 * Allocate a new free-list from blocks of 'blocking_factor' objects of size 47 * node_size. The node_size argument should be determined by applying 48 * the sizeof() operator to the object type that you intend to allocate from 49 * the freelist. 50 */ 51 FreeList *_new_FreeList(size_t node_size, unsigned blocking_factor); 52 53 /* 54 * If it is known that none of the nodes currently allocated from 55 * a freelist are still in use, the following function can be called 56 * to return all nodes to the freelist without the overhead of 57 * having to call del_FreeListNode() for every allocated node. The 58 * nodes of the freelist can then be reused by future callers to 59 * new_FreeListNode(). 60 */ 61 void _rst_FreeList(FreeList *fl); 62 63 /* 64 * Delete a free-list. 65 */ 66 FreeList *_del_FreeList(FreeList *fl, int force); 67 68 /* 69 * Determine the number of nodes that are currently in use. 70 */ 71 long _busy_FreeListNodes(FreeList *fl); 72 73 /* 74 * Query the number of allocated nodes in the freelist which are 75 * currently unused. 76 */ 77 long _idle_FreeListNodes(FreeList *fl); 78 79 /* 80 * Allocate a new object from a free-list. 81 */ 82 void *_new_FreeListNode(FreeList *fl); 83 84 /* 85 * Return an object to the free-list that it was allocated from. 86 */ 87 void *_del_FreeListNode(FreeList *fl, void *object); 88 89 #endif 90