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Diffstat (limited to 'include/mpool.h')
| -rw-r--r-- | include/mpool.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/include/mpool.h b/include/mpool.h new file mode 100644 index 0000000..3f22ab7 --- /dev/null +++ b/include/mpool.h @@ -0,0 +1,109 @@ +/*- + * 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 + * $FreeBSD$ + */ + +#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 { + TAILQ_ENTRY(_bkt) hq; /* hash queue */ + TAILQ_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 { + TAILQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */ + /* hash queue array */ + TAILQ_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 |
