/* $OpenBSD: mpool.h,v 1.10 2004/01/22 21:48:02 espie Exp $ */ /* $NetBSD: mpool.h,v 1.7 1996/05/03 21:13:41 cgd Exp $ */ /*- * Copyright (c) 1991, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)mpool.h 8.4 (Berkeley) 11/2/95 */ #ifndef _MPOOL_H_ #define _MPOOL_H_ #include <sys/queue.h> /* * The memory pool scheme is a simple one. Each in-memory page is referenced * by a bucket which is threaded in up to two of three ways. All active pages * are threaded on a hash chain (hashed by page number) and an lru chain. * Inactive pages are threaded on a free chain. Each reference to a memory * pool is handed an opaque MPOOL cookie which stores all of this information. */ #define HASHSIZE 128 #define HASHKEY(pgno) ((pgno - 1 + HASHSIZE) % HASHSIZE) /* The BKT structures are the elements of the queues. */ typedef struct _bkt { CIRCLEQ_ENTRY(_bkt) hq; /* hash queue */ CIRCLEQ_ENTRY(_bkt) q; /* lru queue */ void *page; /* page */ pgno_t pgno; /* page number */ #define MPOOL_DIRTY 0x01 /* page needs to be written */ #define MPOOL_PINNED 0x02 /* page is pinned into memory */ #define MPOOL_INUSE 0x04 /* page address is valid */ u_int8_t flags; /* flags */ } BKT; typedef struct MPOOL { CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ /* hash queue array */ CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; pgno_t curcache; /* current number of cached pages */ pgno_t maxcache; /* max number of cached pages */ pgno_t npages; /* number of pages in the file */ unsigned long pagesize; /* file page size */ int fd; /* file descriptor */ /* page in conversion routine */ void (*pgin)(void *, pgno_t, void *); /* page out conversion routine */ void (*pgout)(void *, pgno_t, void *); void *pgcookie; /* cookie for page in/out routines */ #ifdef STATISTICS unsigned long cachehit; unsigned long cachemiss; unsigned long pagealloc; unsigned long pageflush; unsigned long pageget; unsigned long pagenew; unsigned long pageput; unsigned long pageread; unsigned long pagewrite; #endif } MPOOL; #define MPOOL_IGNOREPIN 0x01 /* Ignore if the page is pinned. */ #define MPOOL_PAGE_REQUEST 0x01 /* Allocate a new page with a specific page number. */ #define MPOOL_PAGE_NEXT 0x02 /* Allocate a new page with the next page number. */ __BEGIN_DECLS MPOOL *mpool_open(void *, int, pgno_t, pgno_t); void mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *), void (*)(void *, pgno_t, void *), void *); void *mpool_new(MPOOL *, pgno_t *, unsigned int); void *mpool_get(MPOOL *, pgno_t, unsigned int); int mpool_delete(MPOOL *, void *); int mpool_put(MPOOL *, void *, unsigned int); int mpool_sync(MPOOL *); int mpool_close(MPOOL *); #ifdef STATISTICS void mpool_stat(MPOOL *); #endif __END_DECLS #endif