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 #include <bsd-queue.h> 37 #include <filevtable.h> 38 39 /* 40 * The memory pool scheme is a simple one. Each in-memory page is referenced 41 * by a bucket which is threaded in up to two of three ways. All active pages 42 * are threaded on a hash chain (hashed by page number) and an lru chain. 43 * Inactive pages are threaded on a free chain. Each reference to a memory 44 * pool is handed an opaque MPOOL cookie which stores all of this information. 45 */ 46 #define HASHSIZE 128 47 #define HASHKEY(pgno) ((pgno - 1) % HASHSIZE) 48 49 /* The BKT structures are the elements of the queues. */ 50 typedef struct _bkt { 51 CIRCLEQ_ENTRY(_bkt) hq; /* hash queue */ 52 CIRCLEQ_ENTRY(_bkt) q; /* lru queue */ 53 void *page; /* page */ 54 pgno_t pgno; /* page number */ 55 56 #define MPOOL_DIRTY 0x01 /* page needs to be written */ 57 #define MPOOL_PINNED 0x02 /* page is pinned into memory */ 58 u_int8_t flags; /* flags */ 59 } BKT; 60 61 typedef struct MPOOL { 62 CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ 63 /* hash queue array */ 64 CIRCLEQ_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 u_long pagesize; /* file page size */ 69 virt_fd_t fd; /* virtual file descriptor */ 70 /* page in conversion routine */ 71 const FILEVTABLE *fvtable; 72 void (*pgin) __P((void *, pgno_t, void *)); 73 /* page out conversion routine */ 74 void (*pgout) __P((void *, pgno_t, void *)); 75 void *pgcookie; /* cookie for page in/out routines */ 76 #ifdef STATISTICS 77 u_long cachehit; 78 u_long cachemiss; 79 u_long pagealloc; 80 u_long pageflush; 81 u_long pageget; 82 u_long pagenew; 83 u_long pageput; 84 u_long pageread; 85 u_long pagewrite; 86 #endif 87 } MPOOL; 88 89 __BEGIN_DECLS 90 MPOOL *mpool_open __P((void *, virt_fd_t, const FILEVTABLE *, pgno_t, pgno_t)); 91 void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *), 92 void (*)(void *, pgno_t, void *), void *)); 93 void *mpool_new __P((MPOOL *, pgno_t *)); 94 void *mpool_get __P((MPOOL *, pgno_t, u_int)); 95 int mpool_put __P((MPOOL *, void *, u_int)); 96 int mpool_sync __P((MPOOL *)); 97 int mpool_close __P((MPOOL *)); 98 #ifdef STATISTICS 99 void mpool_stat __P((MPOOL *)); 100 #endif 101 __END_DECLS 102