1/* $NetBSD: mpool.h,v 1.16 2016/09/24 21:18:09 christos Exp $ */ 2 3/*- 4 * Copyright (c) 1991, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)mpool.h 8.2 (Berkeley) 7/14/94 32 */ 33 34#ifndef _MPOOL_H_ 35#define _MPOOL_H_ 36 37#include <sys/cdefs.h> 38#include <sys/queue.h> 39 40/* 41 * The memory pool scheme is a simple one. Each in-memory page is referenced 42 * by a bucket which is threaded in up to two of three ways. All active pages 43 * are threaded on a hash chain (hashed by page number) and an lru chain. 44 * Inactive pages are threaded on a free chain. Each reference to a memory 45 * pool is handed an opaque MPOOL cookie which stores all of this information. 46 */ 47#define HASHSIZE 128 48#define HASHKEY(pgno) ((pgno - 1) % HASHSIZE) 49 50/* The BKT structures are the elements of the queues. */ 51typedef struct _bkt { 52 TAILQ_ENTRY(_bkt) hq; /* hash queue */ 53 TAILQ_ENTRY(_bkt) q; /* lru queue */ 54 void *page; /* page */ 55 pgno_t pgno; /* page number */ 56 57#define MPOOL_DIRTY 0x01 /* page needs to be written */ 58#define MPOOL_PINNED 0x02 /* page is pinned into memory */ 59#define MPOOL_INUSE 0x04 /* page address is valid */ 60 uint8_t flags; /* flags */ 61} BKT; 62 63typedef struct MPOOL { 64 TAILQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ 65 /* hash queue array */ 66 TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; 67 pgno_t curcache; /* current number of cached pages */ 68 pgno_t maxcache; /* max number of cached pages */ 69 pgno_t npages; /* number of pages in the file */ 70 unsigned long pagesize; /* file page size */ 71 int fd; /* file descriptor */ 72 /* page in conversion routine */ 73 void (*pgin)(void *, pgno_t, void *); 74 /* page out conversion routine */ 75 void (*pgout)(void *, pgno_t, void *); 76 void *pgcookie; /* cookie for page in/out routines */ 77#ifdef STATISTICS 78 unsigned long cachehit; 79 unsigned long cachemiss; 80 unsigned long pagealloc; 81 unsigned long pageflush; 82 unsigned long pageget; 83 unsigned long pagenew; 84 unsigned long pageput; 85 unsigned long pageread; 86 unsigned long pagewrite; 87#endif 88} MPOOL; 89 90/* flags for get/put */ 91#define MPOOL_IGNOREPIN 0x01 /* Ignore if the page is pinned. */ 92/* flags for newf */ 93#define MPOOL_PAGE_REQUEST 0x01 /* Allocate a new page with a 94 specific page number. */ 95#define MPOOL_PAGE_NEXT 0x02 /* Allocate a new page with the next 96 page number. */ 97 98__BEGIN_DECLS 99MPOOL *mpool_open(void *, int, pgno_t, pgno_t); 100void mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *), 101 void (*)(void *, pgno_t, void *), void *); 102void *mpool_new(MPOOL *, pgno_t *); 103void *mpool_newf(MPOOL *, pgno_t *, unsigned int); 104int mpool_delete(MPOOL *, void *); 105void *mpool_get(MPOOL *, pgno_t, unsigned int); 106int mpool_put(MPOOL *, void *, unsigned int); 107int mpool_sync(MPOOL *); 108int mpool_close(MPOOL *); 109#ifdef STATISTICS 110void mpool_stat(MPOOL *); 111#endif 112__END_DECLS 113 114#endif /* _MPOOL_H_ */ 115