1 /* $NetBSD: mpool.h,v 1.9 2000/07/07 10:43:54 ad 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)mpool.h 8.2 (Berkeley) 7/14/94 36 */ 37 38 #ifndef _MPOOL_H_ 39 #define _MPOOL_H_ 40 41 #include <sys/cdefs.h> 42 #include <sys/queue.h> 43 44 /* 45 * The memory pool scheme is a simple one. Each in-memory page is referenced 46 * by a bucket which is threaded in up to two of three ways. All active pages 47 * are threaded on a hash chain (hashed by page number) and an lru chain. 48 * Inactive pages are threaded on a free chain. Each reference to a memory 49 * pool is handed an opaque MPOOL cookie which stores all of this information. 50 */ 51 #define HASHSIZE 128 52 #define HASHKEY(pgno) ((pgno - 1) % HASHSIZE) 53 54 /* The BKT structures are the elements of the queues. */ 55 typedef struct _bkt { 56 CIRCLEQ_ENTRY(_bkt) hq; /* hash queue */ 57 CIRCLEQ_ENTRY(_bkt) q; /* lru queue */ 58 void *page; /* page */ 59 pgno_t pgno; /* page number */ 60 61 #define MPOOL_DIRTY 0x01 /* page needs to be written */ 62 #define MPOOL_PINNED 0x02 /* page is pinned into memory */ 63 u_int8_t flags; /* flags */ 64 } BKT; 65 66 typedef struct MPOOL { 67 CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ 68 /* hash queue array */ 69 CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; 70 pgno_t curcache; /* current number of cached pages */ 71 pgno_t maxcache; /* max number of cached pages */ 72 pgno_t npages; /* number of pages in the file */ 73 u_long pagesize; /* file page size */ 74 int fd; /* file descriptor */ 75 /* page in conversion routine */ 76 void (*pgin) __P((void *, pgno_t, void *)); 77 /* page out conversion routine */ 78 void (*pgout) __P((void *, pgno_t, void *)); 79 void *pgcookie; /* cookie for page in/out routines */ 80 #ifdef STATISTICS 81 u_long cachehit; 82 u_long cachemiss; 83 u_long pagealloc; 84 u_long pageflush; 85 u_long pageget; 86 u_long pagenew; 87 u_long pageput; 88 u_long pageread; 89 u_long pagewrite; 90 #endif 91 } MPOOL; 92 93 __BEGIN_DECLS 94 MPOOL *mpool_open __P((void *, int, pgno_t, pgno_t)); 95 void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *), 96 void (*)(void *, pgno_t, void *), void *)); 97 void *mpool_new __P((MPOOL *, pgno_t *)); 98 void *mpool_get __P((MPOOL *, pgno_t, u_int)); 99 int mpool_put __P((MPOOL *, void *, u_int)); 100 int mpool_sync __P((MPOOL *)); 101 int mpool_close __P((MPOOL *)); 102 #ifdef STATISTICS 103 void mpool_stat __P((MPOOL *)); 104 #endif 105 __END_DECLS 106 107 #endif /* _MPOOL_H_ */ 108