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984263bc MD |
1 | /*- |
2 | * Copyright (c) 1991, 1993, 1994 | |
3 | * The Regents of the University of California. All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by the University of | |
16 | * California, Berkeley and its contributors. | |
17 | * 4. Neither the name of the University nor the names of its contributors | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | * | |
33 | * @(#)mpool.h 8.2 (Berkeley) 7/14/94 | |
34 | * $FreeBSD: src/include/mpool.h,v 1.5.6.2 2001/03/05 23:05:08 obrien Exp $ | |
7c4af8e1 | 35 | * $DragonFly: src/include/mpool.h,v 1.3 2003/11/14 01:01:43 dillon Exp $ |
984263bc MD |
36 | */ |
37 | ||
38 | #ifndef _MPOOL_H_ | |
39 | #define _MPOOL_H_ | |
40 | ||
41 | #include <sys/queue.h> | |
42 | ||
43 | /* | |
44 | * The memory pool scheme is a simple one. Each in-memory page is referenced | |
45 | * by a bucket which is threaded in up to two of three ways. All active pages | |
46 | * are threaded on a hash chain (hashed by page number) and an lru chain. | |
47 | * Inactive pages are threaded on a free chain. Each reference to a memory | |
48 | * pool is handed an opaque MPOOL cookie which stores all of this information. | |
49 | */ | |
50 | #define HASHSIZE 128 | |
51 | #define HASHKEY(pgno) ((pgno - 1) % HASHSIZE) | |
52 | ||
53 | /* The BKT structures are the elements of the queues. */ | |
54 | typedef struct _bkt { | |
55 | TAILQ_ENTRY(_bkt) hq; /* hash queue */ | |
56 | TAILQ_ENTRY(_bkt) q; /* lru queue */ | |
57 | void *page; /* page */ | |
58 | pgno_t pgno; /* page number */ | |
59 | ||
60 | #define MPOOL_DIRTY 0x01 /* page needs to be written */ | |
61 | #define MPOOL_PINNED 0x02 /* page is pinned into memory */ | |
62 | u_int8_t flags; /* flags */ | |
63 | } BKT; | |
64 | ||
65 | typedef struct MPOOL { | |
66 | TAILQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ | |
67 | /* hash queue array */ | |
68 | TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; | |
69 | pgno_t curcache; /* current number of cached pages */ | |
70 | pgno_t maxcache; /* max number of cached pages */ | |
71 | pgno_t npages; /* number of pages in the file */ | |
72 | u_long pagesize; /* file page size */ | |
73 | int fd; /* file descriptor */ | |
74 | /* page in conversion routine */ | |
7c4af8e1 | 75 | void (*pgin) (void *, pgno_t, void *); |
984263bc | 76 | /* page out conversion routine */ |
7c4af8e1 | 77 | void (*pgout) (void *, pgno_t, void *); |
984263bc MD |
78 | void *pgcookie; /* cookie for page in/out routines */ |
79 | #ifdef STATISTICS | |
80 | u_long cachehit; | |
81 | u_long cachemiss; | |
82 | u_long pagealloc; | |
83 | u_long pageflush; | |
84 | u_long pageget; | |
85 | u_long pagenew; | |
86 | u_long pageput; | |
87 | u_long pageread; | |
88 | u_long pagewrite; | |
89 | #endif | |
90 | } MPOOL; | |
91 | ||
92 | __BEGIN_DECLS | |
7c4af8e1 MD |
93 | MPOOL *mpool_open (void *, int, pgno_t, pgno_t); |
94 | void mpool_filter (MPOOL *, void (*)(void *, pgno_t, void *), | |
95 | void (*)(void *, pgno_t, void *), void *); | |
96 | void *mpool_new (MPOOL *, pgno_t *); | |
97 | void *mpool_get (MPOOL *, pgno_t, u_int); | |
98 | int mpool_put (MPOOL *, void *, u_int); | |
99 | int mpool_sync (MPOOL *); | |
100 | int mpool_close (MPOOL *); | |
984263bc | 101 | #ifdef STATISTICS |
7c4af8e1 | 102 | void mpool_stat (MPOOL *); |
984263bc MD |
103 | #endif |
104 | __END_DECLS | |
105 | ||
106 | #endif |