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- /* $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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. 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 8.2 (Berkeley) 7/14/94
- */
-
- #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)
-
- /* 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 */
- 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 */
- u_long pagesize; /* file page size */
- int fd; /* file descriptor */
- /* page in conversion routine */
- void (*pgin) __P((void *, pgno_t, void *));
- /* page out conversion routine */
- void (*pgout) __P((void *, pgno_t, void *));
- void *pgcookie; /* cookie for page in/out routines */
- #ifdef STATISTICS
- u_long cachehit;
- u_long cachemiss;
- u_long pagealloc;
- u_long pageflush;
- u_long pageget;
- u_long pagenew;
- u_long pageput;
- u_long pageread;
- u_long pagewrite;
- #endif
- } MPOOL;
-
- __BEGIN_DECLS
- MPOOL *mpool_open __P((void *, int, pgno_t, pgno_t));
- void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *),
- void (*)(void *, pgno_t, void *), void *));
- void *mpool_new __P((MPOOL *, pgno_t *));
- void *mpool_get __P((MPOOL *, pgno_t, u_int));
- int mpool_put __P((MPOOL *, void *, u_int));
- int mpool_sync __P((MPOOL *));
- int mpool_close __P((MPOOL *));
- #ifdef STATISTICS
- void mpool_stat __P((MPOOL *));
- #endif
- __END_DECLS
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