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1 /*
2 * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23 /*-
24 * Copyright (c) 1991, 1993, 1994
25 * The Regents of the University of California. All rights reserved.
26 *
27 * Redistribution and use in source and binary forms, with or without
28 * modification, are permitted provided that the following conditions
29 * are met:
30 * 1. Redistributions of source code must retain the above copyright
31 * notice, this list of conditions and the following disclaimer.
32 * 2. Redistributions in binary form must reproduce the above copyright
33 * notice, this list of conditions and the following disclaimer in the
34 * documentation and/or other materials provided with the distribution.
35 * 3. All advertising materials mentioning features or use of this software
36 * must display the following acknowledgement:
37 * This product includes software developed by the University of
38 * California, Berkeley and its contributors.
39 * 4. Neither the name of the University nor the names of its contributors
40 * may be used to endorse or promote products derived from this software
41 * without specific prior written permission.
42 *
43 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
44 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
47 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * SUCH DAMAGE.
54 *
55 * @(#)mpool.h 8.2 (Berkeley) 7/14/94
56 * $FreeBSD: src/include/mpool.h,v 1.9 2002/03/23 17:24:53 imp Exp $
57 */
58
59 #ifndef _MPOOL_H_
60 #define _MPOOL_H_
61
62 #include <sys/queue.h>
63
64 /*
65 * The memory pool scheme is a simple one. Each in-memory page is referenced
66 * by a bucket which is threaded in up to two of three ways. All active pages
67 * are threaded on a hash chain (hashed by page number) and an lru chain.
68 * Inactive pages are threaded on a free chain. Each reference to a memory
69 * pool is handed an opaque MPOOL cookie which stores all of this information.
70 */
71 #define HASHSIZE 128
72 #define HASHKEY(pgno) ((pgno - 1) % HASHSIZE)
73
74 /* The BKT structures are the elements of the queues. */
75 typedef struct _bkt {
76 TAILQ_ENTRY(_bkt) hq; /* hash queue */
77 TAILQ_ENTRY(_bkt) q; /* lru queue */
78 void *page; /* page */
79 pgno_t pgno; /* page number */
80
81 #define MPOOL_DIRTY 0x01 /* page needs to be written */
82 #define MPOOL_PINNED 0x02 /* page is pinned into memory */
83 u_int8_t flags; /* flags */
84 } BKT;
85
86 typedef struct MPOOL {
87 TAILQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */
88 /* hash queue array */
89 TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
90 pgno_t curcache; /* current number of cached pages */
91 pgno_t maxcache; /* max number of cached pages */
92 pgno_t npages; /* number of pages in the file */
93 u_long pagesize; /* file page size */
94 int fd; /* file descriptor */
95 /* page in conversion routine */
96 void (*pgin)(void *, pgno_t, void *);
97 /* page out conversion routine */
98 void (*pgout)(void *, pgno_t, void *);
99 void *pgcookie; /* cookie for page in/out routines */
100 #ifdef STATISTICS
101 u_long cachehit;
102 u_long cachemiss;
103 u_long pagealloc;
104 u_long pageflush;
105 u_long pageget;
106 u_long pagenew;
107 u_long pageput;
108 u_long pageread;
109 u_long pagewrite;
110 #endif
111 } MPOOL;
112
113 __BEGIN_DECLS
114 MPOOL *mpool_open(void *, int, pgno_t, pgno_t);
115 void mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *),
116 void (*)(void *, pgno_t, void *), void *);
117 void *mpool_new(MPOOL *, pgno_t *);
118 void *mpool_get(MPOOL *, pgno_t, u_int);
119 int mpool_put(MPOOL *, void *, u_int);
120 int mpool_sync(MPOOL *);
121 int mpool_close(MPOOL *);
122 #ifdef STATISTICS
123 void mpool_stat(MPOOL *);
124 #endif
125 __END_DECLS
126
127 #endif