| 1 | /*- |
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| 2 | * Copyright (c) 1991, 1993, 1994 |
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| 3 | * The Regents of the University of California. All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * 1. Redistributions of source code must retain the above copyright |
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| 9 | * notice, this list of conditions and the following disclaimer. |
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| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer in the |
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| 12 | * documentation and/or other materials provided with the distribution. |
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| 13 | * 3. All advertising materials mentioning features or use of this software |
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| 14 | * must display the following acknowledgement: |
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| 15 | * This product includes software developed by the University of |
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| 16 | * California, Berkeley and its contributors. |
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| 17 | * 4. Neither the name of the University nor the names of its contributors |
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| 18 | * may be used to endorse or promote products derived from this software |
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| 19 | * without specific prior written permission. |
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| 20 | * |
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| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 31 | * SUCH DAMAGE. |
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| 32 | * |
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| 33 | * @(#)mpool.h 8.4 (Berkeley) 11/2/95 |
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| 34 | * $FreeBSD$ |
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| 35 | */ |
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| 36 | |
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| 37 | #ifndef _MPOOL_H_ |
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| 38 | #define _MPOOL_H_ |
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| 39 | |
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| 40 | #include <sys/queue.h> |
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| 41 | |
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| 42 | /* |
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| 43 | * The memory pool scheme is a simple one. Each in-memory page is referenced |
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| 44 | * by a bucket which is threaded in up to two of three ways. All active pages |
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| 45 | * are threaded on a hash chain (hashed by page number) and an lru chain. |
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| 46 | * Inactive pages are threaded on a free chain. Each reference to a memory |
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| 47 | * pool is handed an opaque MPOOL cookie which stores all of this information. |
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| 48 | */ |
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| 49 | #define HASHSIZE 128 |
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| 50 | #define HASHKEY(pgno) ((pgno - 1 + HASHSIZE) % HASHSIZE) |
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| 51 | |
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| 52 | /* The BKT structures are the elements of the queues. */ |
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| 53 | typedef struct _bkt { |
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| 54 | TAILQ_ENTRY(_bkt) hq; /* hash queue */ |
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| 55 | TAILQ_ENTRY(_bkt) q; /* lru queue */ |
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| 56 | void *page; /* page */ |
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| 57 | pgno_t pgno; /* page number */ |
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| 58 | |
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| 59 | #define MPOOL_DIRTY 0x01 /* page needs to be written */ |
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| 60 | #define MPOOL_PINNED 0x02 /* page is pinned into memory */ |
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| 61 | #define MPOOL_INUSE 0x04 /* page address is valid */ |
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| 62 | u_int8_t flags; /* flags */ |
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| 63 | } BKT; |
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| 64 | |
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| 65 | typedef struct MPOOL { |
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| 66 | TAILQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ |
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| 67 | /* hash queue array */ |
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| 68 | TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; |
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| 69 | pgno_t curcache; /* current number of cached pages */ |
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| 70 | pgno_t maxcache; /* max number of cached pages */ |
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| 71 | pgno_t npages; /* number of pages in the file */ |
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| 72 | unsigned long pagesize; /* file page size */ |
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| 73 | int fd; /* file descriptor */ |
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| 74 | /* page in conversion routine */ |
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| 75 | void (*pgin)(void *, pgno_t, void *); |
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| 76 | /* page out conversion routine */ |
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| 77 | void (*pgout)(void *, pgno_t, void *); |
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| 78 | void *pgcookie; /* cookie for page in/out routines */ |
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| 79 | #ifdef STATISTICS |
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| 80 | unsigned long cachehit; |
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| 81 | unsigned long cachemiss; |
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| 82 | unsigned long pagealloc; |
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| 83 | unsigned long pageflush; |
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| 84 | unsigned long pageget; |
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| 85 | unsigned long pagenew; |
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| 86 | unsigned long pageput; |
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| 87 | unsigned long pageread; |
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| 88 | unsigned long pagewrite; |
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| 89 | #endif |
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| 90 | } MPOOL; |
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| 91 | |
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| 92 | #define MPOOL_IGNOREPIN 0x01 /* Ignore if the page is pinned. */ |
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| 93 | #define MPOOL_PAGE_REQUEST 0x01 /* Allocate a new page with a |
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| 94 | specific page number. */ |
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| 95 | #define MPOOL_PAGE_NEXT 0x02 /* Allocate a new page with the next |
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| 96 | page number. */ |
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| 97 | |
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| 98 | __BEGIN_DECLS |
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| 99 | MPOOL *mpool_open(void *, int, pgno_t, pgno_t); |
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| 100 | void mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *), |
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| 101 | void (*)(void *, pgno_t, void *), void *); |
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| 102 | void *mpool_new(MPOOL *, pgno_t *, unsigned int); |
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| 103 | void *mpool_get(MPOOL *, pgno_t, unsigned int); |
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| 104 | int mpool_delete(MPOOL *, void *); |
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| 105 | int mpool_put(MPOOL *, void *, unsigned int); |
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| 106 | int mpool_sync(MPOOL *); |
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| 107 | int mpool_close(MPOOL *); |
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| 108 | #ifdef STATISTICS |
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| 109 | void mpool_stat(MPOOL *); |
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| 110 | #endif |
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| 111 | __END_DECLS |
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| 112 | |
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| 113 | #endif |
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