Merge from vendor branch GCC:
[dragonfly.git] / include / mpool.h
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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 $
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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. */
54typedef 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
65typedef 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 *);
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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
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93MPOOL *mpool_open (void *, int, pgno_t, pgno_t);
94void mpool_filter (MPOOL *, void (*)(void *, pgno_t, void *),
95 void (*)(void *, pgno_t, void *), void *);
96void *mpool_new (MPOOL *, pgno_t *);
97void *mpool_get (MPOOL *, pgno_t, u_int);
98int mpool_put (MPOOL *, void *, u_int);
99int mpool_sync (MPOOL *);
100int mpool_close (MPOOL *);
984263bc 101#ifdef STATISTICS
7c4af8e1 102void mpool_stat (MPOOL *);
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103#endif
104__END_DECLS
105
106#endif