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 */ 35 36 #ifndef _MPOOL_H_ 37 #define _MPOOL_H_ 38 39 #include <sys/queue.h> 40 41 /* 42 * The memory pool scheme is a simple one. Each in-memory page is referenced 43 * by a bucket which is threaded in up to two of three ways. All active pages 44 * are threaded on a hash chain (hashed by page number) and an lru chain. 45 * Inactive pages are threaded on a free chain. Each reference to a memory 46 * pool is handed an opaque MPOOL cookie which stores all of this information. 47 */ 48 #define HASHSIZE 128 49 #define HASHKEY(pgno) ((pgno - 1) % HASHSIZE) 50 51 /* The BKT structures are the elements of the queues. */ 52 typedef struct _bkt { 53 CIRCLEQ_ENTRY(_bkt) hq; /* hash queue */ 54 CIRCLEQ_ENTRY(_bkt) q; /* lru queue */ 55 void *page; /* page */ 56 pgno_t pgno; /* page number */ 57 58 #define MPOOL_DIRTY 0x01 /* page needs to be written */ 59 #define MPOOL_PINNED 0x02 /* page is pinned into memory */ 60 u_int8_t flags; /* flags */ 61 } BKT; 62 63 typedef struct MPOOL { 64 CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ 65 /* hash queue array */ 66 CIRCLEQ_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 u_long pagesize; /* file page size */ 71 int fd; /* file descriptor */ 72 /* page in conversion routine */ 73 void (*pgin) __P((void *, pgno_t, void *)); 74 /* page out conversion routine */ 75 void (*pgout) __P((void *, pgno_t, void *)); 76 void *pgcookie; /* cookie for page in/out routines */ 77 #ifdef STATISTICS 78 u_long cachehit; 79 u_long cachemiss; 80 u_long pagealloc; 81 u_long pageflush; 82 u_long pageget; 83 u_long pagenew; 84 u_long pageput; 85 u_long pageread; 86 u_long pagewrite; 87 #endif 88 } MPOOL; 89 90 __BEGIN_DECLS 91 MPOOL *mpool_open __P((void *, int, pgno_t, pgno_t)); 92 void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *), 93 void (*)(void *, pgno_t, void *), void *)); 94 void *mpool_new __P((MPOOL *, pgno_t *)); 95 void *mpool_get __P((MPOOL *, pgno_t, u_int)); 96 int mpool_put __P((MPOOL *, void *, u_int)); 97 int mpool_sync __P((MPOOL *)); 98 int mpool_close __P((MPOOL *)); 99 #ifdef STATISTICS 100 void mpool_stat __P((MPOOL *)); 101 #endif 102 __END_DECLS 103 104 #endif 105