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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)mpool.h 8.4 (Berkeley) 11/2/95 30 * $FreeBSD: head/include/mpool.h 203964 2010-02-16 19:39:50Z imp $ 31 */ 32 33 #ifndef _MPOOL_H_ 34 #define _MPOOL_H_ 35 36 #include <sys/queue.h> 37 38 /* 39 * The memory pool scheme is a simple one. Each in-memory page is referenced 40 * by a bucket which is threaded in up to two of three ways. All active pages 41 * are threaded on a hash chain (hashed by page number) and an lru chain. 42 * Inactive pages are threaded on a free chain. Each reference to a memory 43 * pool is handed an opaque MPOOL cookie which stores all of this information. 44 */ 45 #define HASHSIZE 128 46 #define HASHKEY(pgno) ((pgno - 1 + HASHSIZE) % HASHSIZE) 47 48 /* The BKT structures are the elements of the queues. */ 49 typedef struct _bkt { 50 TAILQ_ENTRY(_bkt) hq; /* hash queue */ 51 TAILQ_ENTRY(_bkt) q; /* lru queue */ 52 void *page; /* page */ 53 pgno_t pgno; /* page number */ 54 55 #define MPOOL_DIRTY 0x01 /* page needs to be written */ 56 #define MPOOL_PINNED 0x02 /* page is pinned into memory */ 57 #define MPOOL_INUSE 0x04 /* page address is valid */ 58 u_int8_t flags; /* flags */ 59 } BKT; 60 61 typedef struct MPOOL { 62 TAILQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ 63 /* hash queue array */ 64 TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; 65 pgno_t curcache; /* current number of cached pages */ 66 pgno_t maxcache; /* max number of cached pages */ 67 pgno_t npages; /* number of pages in the file */ 68 unsigned long pagesize; /* file page size */ 69 int fd; /* file descriptor */ 70 /* page in conversion routine */ 71 void (*pgin)(void *, pgno_t, void *); 72 /* page out conversion routine */ 73 void (*pgout)(void *, pgno_t, void *); 74 void *pgcookie; /* cookie for page in/out routines */ 75 #ifdef STATISTICS 76 unsigned long cachehit; 77 unsigned long cachemiss; 78 unsigned long pagealloc; 79 unsigned long pageflush; 80 unsigned long pageget; 81 unsigned long pagenew; 82 unsigned long pageput; 83 unsigned long pageread; 84 unsigned long pagewrite; 85 #endif 86 } MPOOL; 87 88 #define MPOOL_IGNOREPIN 0x01 /* Ignore if the page is pinned. */ 89 #define MPOOL_PAGE_REQUEST 0x01 /* Allocate a new page with a 90 specific page number. */ 91 #define MPOOL_PAGE_NEXT 0x02 /* Allocate a new page with the next 92 page number. */ 93 94 __BEGIN_DECLS 95 MPOOL *mpool_open(void *, int, pgno_t, pgno_t); 96 void mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *), 97 void (*)(void *, pgno_t, void *), void *); 98 void *mpool_new(MPOOL *, pgno_t *, unsigned int); 99 void *mpool_get(MPOOL *, pgno_t, unsigned int); 100 int mpool_delete(MPOOL *, void *); 101 int mpool_put(MPOOL *, void *, unsigned int); 102 int mpool_sync(MPOOL *); 103 int mpool_close(MPOOL *); 104 #ifdef STATISTICS 105 void mpool_stat(MPOOL *); 106 #endif 107 __END_DECLS 108 109 #endif 110