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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libc/db/mpool/mpool.c	Lines:	0	119	0.0 %
Date:	2017-11-07	Branches:	0	81	0.0 %


/*	$OpenBSD: mpool.c,v 1.21 2015/11/01 03:45:28 guenther Exp $	*/

/*-
 * Copyright (c) 1990, 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.
 */

#include <sys/queue.h>
#include <sys/stat.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <db.h>

#define	__MPOOLINTERFACE_PRIVATE
#include <mpool.h>

static BKT *mpool_bkt(MPOOL *);
static BKT *mpool_look(MPOOL *, pgno_t);
static int  mpool_write(MPOOL *, BKT *);

/*
 * mpool_open --
 *	Initialize a memory pool.
 */
MPOOL *
mpool_open(void *key, int fd, pgno_t pagesize, pgno_t maxcache)
{
	struct stat sb;
	MPOOL *mp;
	int entry;

	/*
	 * Get information about the file.
	 *
	 * XXX
	 * We don't currently handle pipes, although we should.
	 */
	if (fstat(fd, &sb))
		return (NULL);
	if (!S_ISREG(sb.st_mode)) {
		errno = ESPIPE;
		return (NULL);
	}

	/* Allocate and initialize the MPOOL cookie. */
	if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
		return (NULL);
	TAILQ_INIT(&mp->lqh);
	for (entry = 0; entry < HASHSIZE; ++entry)
		TAILQ_INIT(&mp->hqh[entry]);
	mp->maxcache = maxcache;
	mp->npages = sb.st_size / pagesize;
	mp->pagesize = pagesize;
	mp->fd = fd;
	return (mp);
}

/*
 * mpool_filter --
 *	Initialize input/output filters.
 */
void
mpool_filter(MPOOL *mp, void (*pgin) (void *, pgno_t, void *),
    void (*pgout) (void *, pgno_t, void *), void *pgcookie)
{
	mp->pgin = pgin;
	mp->pgout = pgout;
	mp->pgcookie = pgcookie;
}

/*
 * mpool_new --
 *	Get a new page of memory.
 */
void *
mpool_new(MPOOL *mp, pgno_t *pgnoaddr, u_int flags)
{
	struct _hqh *head;
	BKT *bp;

	if (mp->npages == MAX_PAGE_NUMBER) {
		(void)fprintf(stderr, "mpool_new: page allocation overflow.\n");
		abort();
	}
#ifdef STATISTICS
	++mp->pagenew;
#endif
	/*
	 * Get a BKT from the cache.  Assign a new page number, attach
	 * it to the head of the hash chain, the tail of the lru chain,
	 * and return.
	 */
	if ((bp = mpool_bkt(mp)) == NULL)
		return (NULL);
	if (flags == MPOOL_PAGE_REQUEST) {
		mp->npages++;
		bp->pgno = *pgnoaddr;
	} else
		bp->pgno = *pgnoaddr = mp->npages++;

	bp->flags = MPOOL_PINNED | MPOOL_INUSE;

	head = &mp->hqh[HASHKEY(bp->pgno)];
	TAILQ_INSERT_HEAD(head, bp, hq);
	TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
	return (bp->page);
}

int
mpool_delete(MPOOL *mp, void *page)
{
	struct _hqh *head;
	BKT *bp;

	bp = (BKT *)((char *)page - sizeof(BKT));

#ifdef DEBUG
	if (!(bp->flags & MPOOL_PINNED)) {
		(void)fprintf(stderr,
		    "mpool_delete: page %d not pinned\n", bp->pgno);
		abort();
	}
#endif

	/* Remove from the hash and lru queues. */
	head = &mp->hqh[HASHKEY(bp->pgno)];
	TAILQ_REMOVE(head, bp, hq);
	TAILQ_REMOVE(&mp->lqh, bp, q);

	free(bp);
	mp->curcache--;
	return (RET_SUCCESS);
}

/*
 * mpool_get
 *	Get a page.
 */
void *
mpool_get(MPOOL *mp, pgno_t pgno,
    u_int flags)		/* XXX not used? */
{
	struct _hqh *head;
	BKT *bp;
	off_t off;
	int nr;

#ifdef STATISTICS
	++mp->pageget;
#endif

	/* Check for a page that is cached. */
	if ((bp = mpool_look(mp, pgno)) != NULL) {
#ifdef DEBUG
		if (!(flags & MPOOL_IGNOREPIN) && bp->flags & MPOOL_PINNED) {
			(void)fprintf(stderr,
			    "mpool_get: page %d already pinned\n", bp->pgno);
			abort();
		}
#endif
		/*
		 * Move the page to the head of the hash chain and the tail
		 * of the lru chain.
		 */
		head = &mp->hqh[HASHKEY(bp->pgno)];
		TAILQ_REMOVE(head, bp, hq);
		TAILQ_INSERT_HEAD(head, bp, hq);
		TAILQ_REMOVE(&mp->lqh, bp, q);
		TAILQ_INSERT_TAIL(&mp->lqh, bp, q);

		/* Return a pinned page. */
		bp->flags |= MPOOL_PINNED;
		return (bp->page);
	}

	/* Get a page from the cache. */
	if ((bp = mpool_bkt(mp)) == NULL)
		return (NULL);

	/* Read in the contents. */
	off = mp->pagesize * pgno;
	if ((nr = pread(mp->fd, bp->page, mp->pagesize, off)) != mp->pagesize) {
		switch (nr) {
		case -1:
			/* errno is set for us by pread(). */
			free(bp);
			mp->curcache--;
			return (NULL);
		case 0:
			/*
			 * A zero-length read means you need to create a
			 * new page.
			 */
			memset(bp->page, 0, mp->pagesize);
			break;
		default:
			/* A partial read is definitely bad. */
			free(bp);
			mp->curcache--;
			errno = EINVAL;
			return (NULL);
		}
	}
#ifdef STATISTICS
	++mp->pageread;
#endif

	/* Set the page number, pin the page. */
	bp->pgno = pgno;
	if (!(flags & MPOOL_IGNOREPIN))
		bp->flags = MPOOL_PINNED;
	bp->flags |= MPOOL_INUSE;

	/*
	 * Add the page to the head of the hash chain and the tail
	 * of the lru chain.
	 */
	head = &mp->hqh[HASHKEY(bp->pgno)];
	TAILQ_INSERT_HEAD(head, bp, hq);
	TAILQ_INSERT_TAIL(&mp->lqh, bp, q);

	/* Run through the user's filter. */
	if (mp->pgin != NULL)
		(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);

	return (bp->page);
}

/*
 * mpool_put
 *	Return a page.
 */
int
mpool_put(MPOOL *mp, void *page, u_int flags)
{
	BKT *bp;

#ifdef STATISTICS
	++mp->pageput;
#endif
	bp = (BKT *)((char *)page - sizeof(BKT));
#ifdef DEBUG
	if (!(bp->flags & MPOOL_PINNED)) {
		(void)fprintf(stderr,
		    "mpool_put: page %d not pinned\n", bp->pgno);
		abort();
	}
#endif
	bp->flags &= ~MPOOL_PINNED;
	if (flags & MPOOL_DIRTY)
		bp->flags |= flags & MPOOL_DIRTY;
	return (RET_SUCCESS);
}

/*
 * mpool_close
 *	Close the buffer pool.
 */
int
mpool_close(MPOOL *mp)
{
	BKT *bp;

	/* Free up any space allocated to the lru pages. */
	while ((bp = TAILQ_FIRST(&mp->lqh))) {
		TAILQ_REMOVE(&mp->lqh, bp, q);
		free(bp);
	}

	/* Free the MPOOL cookie. */
	free(mp);
	return (RET_SUCCESS);
}

/*
 * mpool_sync
 *	Sync the pool to disk.
 */
int
mpool_sync(MPOOL *mp)
{
	BKT *bp;

	/* Walk the lru chain, flushing any dirty pages to disk. */
	TAILQ_FOREACH(bp, &mp->lqh, q)
		if (bp->flags & MPOOL_DIRTY &&
		    mpool_write(mp, bp) == RET_ERROR)
			return (RET_ERROR);

	/* Sync the file descriptor. */
	return (fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
}

/*
 * mpool_bkt
 *	Get a page from the cache (or create one).
 */
static BKT *
mpool_bkt(MPOOL *mp)
{
	struct _hqh *head;
	BKT *bp;

	/* If under the max cached, always create a new page. */
	if (mp->curcache < mp->maxcache)
		goto new;

	/*
	 * If the cache is max'd out, walk the lru list for a buffer we
	 * can flush.  If we find one, write it (if necessary) and take it
	 * off any lists.  If we don't find anything we grow the cache anyway.
	 * The cache never shrinks.
	 */
	TAILQ_FOREACH(bp, &mp->lqh, q)
		if (!(bp->flags & MPOOL_PINNED)) {
			/* Flush if dirty. */
			if (bp->flags & MPOOL_DIRTY &&
			    mpool_write(mp, bp) == RET_ERROR)
				return (NULL);
#ifdef STATISTICS
			++mp->pageflush;
#endif
			/* Remove from the hash and lru queues. */
			head = &mp->hqh[HASHKEY(bp->pgno)];
			TAILQ_REMOVE(head, bp, hq);
			TAILQ_REMOVE(&mp->lqh, bp, q);
#ifdef DEBUG
			{ void *spage;
				spage = bp->page;
				memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
				bp->page = spage;
			}
#endif
			bp->flags = 0;
			return (bp);
		}

new:	if ((bp = (BKT *)malloc(sizeof(BKT) + mp->pagesize)) == NULL)
		return (NULL);
#ifdef STATISTICS
	++mp->pagealloc;
#endif
	memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
	bp->page = (char *)bp + sizeof(BKT);
	bp->flags = 0;
	++mp->curcache;
	return (bp);
}

/*
 * mpool_write
 *	Write a page to disk.
 */
static int
mpool_write(MPOOL *mp, BKT *bp)
{
	off_t off;

#ifdef STATISTICS
	++mp->pagewrite;
#endif

	/* Run through the user's filter. */
	if (mp->pgout)
		(mp->pgout)(mp->pgcookie, bp->pgno, bp->page);

	off = mp->pagesize * bp->pgno;
	if (pwrite(mp->fd, bp->page, mp->pagesize, off) != mp->pagesize)
		return (RET_ERROR);

	/*
	 * Re-run through the input filter since this page may soon be
	 * accessed via the cache, and whatever the user's output filter
	 * did may screw things up if we don't let the input filter
	 * restore the in-core copy.
	 */
	if (mp->pgin)
		(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);

	bp->flags &= ~MPOOL_DIRTY;
	return (RET_SUCCESS);
}

/*
 * mpool_look
 *	Lookup a page in the cache.
 */
static BKT *
mpool_look(MPOOL *mp, pgno_t pgno)
{
	struct _hqh *head;
	BKT *bp;

	head = &mp->hqh[HASHKEY(pgno)];
	TAILQ_FOREACH(bp, head, hq)
		if ((bp->pgno == pgno) &&
			((bp->flags & MPOOL_INUSE) == MPOOL_INUSE)) {
#ifdef STATISTICS
			++mp->cachehit;
#endif
			return (bp);
		}
#ifdef STATISTICS
	++mp->cachemiss;
#endif
	return (NULL);
}

#ifdef STATISTICS
/*
 * mpool_stat
 *	Print out cache statistics.
 */
void
mpool_stat(MPOOL *mp)
{
	BKT *bp;
	int cnt;
	char *sep;

	(void)fprintf(stderr, "%lu pages in the file\n", mp->npages);
	(void)fprintf(stderr,
	    "page size %lu, cacheing %lu pages of %lu page max cache\n",
	    mp->pagesize, mp->curcache, mp->maxcache);
	(void)fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n",
	    mp->pageput, mp->pageget, mp->pagenew);
	(void)fprintf(stderr, "%lu page allocs, %lu page flushes\n",
	    mp->pagealloc, mp->pageflush);
	if (mp->cachehit + mp->cachemiss)
		(void)fprintf(stderr,
		    "%.0f%% cache hit rate (%lu hits, %lu misses)\n",
		    ((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
		    * 100, mp->cachehit, mp->cachemiss);
	(void)fprintf(stderr, "%lu page reads, %lu page writes\n",
	    mp->pageread, mp->pagewrite);

	sep = "";
	cnt = 0;
	TAILQ_FOREACH(bp, &mp->lqh, q) {
		(void)fprintf(stderr, "%s%d", sep, bp->pgno);
		if (bp->flags & MPOOL_DIRTY)
			(void)fprintf(stderr, "d");
		if (bp->flags & MPOOL_PINNED)
			(void)fprintf(stderr, "P");
		if (++cnt == 10) {
			sep = "\n";
			cnt = 0;
		} else
			sep = ", ";

	}
	(void)fprintf(stderr, "\n");
}
#endif


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: mpool.c,v 1.21 2015/11/01 03:45:28 guenther Exp $ */
2
3			/*-
4			* Copyright (c) 1990, 1993, 1994
5			* The Regents of the University of California. All rights reserved.
6			*
7			* Redistribution and use in source and binary forms, with or without
8			* modification, are permitted provided that the following conditions
9			* are met:
10			* 1. Redistributions of source code must retain the above copyright
11			* notice, this list of conditions and the following disclaimer.
12			* 2. Redistributions in binary form must reproduce the above copyright
13			* notice, this list of conditions and the following disclaimer in the
14			* documentation and/or other materials provided with the distribution.
15			* 3. Neither the name of the University nor the names of its contributors
16			* may be used to endorse or promote products derived from this software
17			* without specific prior written permission.
18			*
19			* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22			* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29			* SUCH DAMAGE.
30			*/
31
32			#include <sys/queue.h>
33			#include <sys/stat.h>
34
35			#include <errno.h>
36			#include <stdio.h>
37			#include <stdlib.h>
38			#include <string.h>
39			#include <unistd.h>
40
41			#include <db.h>
42
43			#define __MPOOLINTERFACE_PRIVATE
44			#include <mpool.h>
45
46			static BKT mpool_bkt(MPOOL );
47			static BKT mpool_look(MPOOL , pgno_t);
48			static int mpool_write(MPOOL , BKT );
49
50			/*
51			* mpool_open --
52			* Initialize a memory pool.
53			*/
54			MPOOL *
55			mpool_open(void *key, int fd, pgno_t pagesize, pgno_t maxcache)
56			{
57			struct stat sb;
58			MPOOL *mp;
59			int entry;
60
61			/*
62			* Get information about the file.
63			*
64			* XXX
65			* We don't currently handle pipes, although we should.
66			*/
67			if (fstat(fd, &sb))
68			return (NULL);
69			if (!S_ISREG(sb.st_mode)) {
70			errno = ESPIPE;
71			return (NULL);
72			}
73
74			/* Allocate and initialize the MPOOL cookie. */
75			if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
76			return (NULL);
77			TAILQ_INIT(&mp->lqh);
78			for (entry = 0; entry < HASHSIZE; ++entry)
79			TAILQ_INIT(&mp->hqh[entry]);
80			mp->maxcache = maxcache;
81			mp->npages = sb.st_size / pagesize;
82			mp->pagesize = pagesize;
83			mp->fd = fd;
84			return (mp);
85			}
86
87			/*
88			* mpool_filter --
89			* Initialize input/output filters.
90			*/
91			void
92			mpool_filter(MPOOL mp, void (pgin) (void , pgno_t, void ),
93			void (pgout) (void , pgno_t, void ), void pgcookie)
94			{
95			mp->pgin = pgin;
96			mp->pgout = pgout;
97			mp->pgcookie = pgcookie;
98			}
99
100			/*
101			* mpool_new --
102			* Get a new page of memory.
103			*/
104			void *
105			mpool_new(MPOOL mp, pgno_t pgnoaddr, u_int flags)
106			{
107			struct _hqh *head;
108			BKT *bp;
109
110			if (mp->npages == MAX_PAGE_NUMBER) {
111			(void)fprintf(stderr, "mpool_new: page allocation overflow.\n");
112			abort();
113			}
114			#ifdef STATISTICS
115			++mp->pagenew;
116			#endif
117			/*
118			* Get a BKT from the cache. Assign a new page number, attach
119			* it to the head of the hash chain, the tail of the lru chain,
120			* and return.
121			*/
122			if ((bp = mpool_bkt(mp)) == NULL)
123			return (NULL);
124			if (flags == MPOOL_PAGE_REQUEST) {
125			mp->npages++;
126			bp->pgno = *pgnoaddr;
127			} else
128			bp->pgno = *pgnoaddr = mp->npages++;
129
130			bp->flags = MPOOL_PINNED \| MPOOL_INUSE;
131
132			head = &mp->hqh[HASHKEY(bp->pgno)];
133			TAILQ_INSERT_HEAD(head, bp, hq);
134			TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
135			return (bp->page);
136			}
137
138			int
139			mpool_delete(MPOOL mp, void page)
140			{
141			struct _hqh *head;
142			BKT *bp;
143
144			bp = (BKT )((char )page - sizeof(BKT));
145
146			#ifdef DEBUG
147			if (!(bp->flags & MPOOL_PINNED)) {
148			(void)fprintf(stderr,
149			"mpool_delete: page %d not pinned\n", bp->pgno);
150			abort();
151			}
152			#endif
153
154			/* Remove from the hash and lru queues. */
155			head = &mp->hqh[HASHKEY(bp->pgno)];
156			TAILQ_REMOVE(head, bp, hq);
157			TAILQ_REMOVE(&mp->lqh, bp, q);
158
159			free(bp);
160			mp->curcache--;
161			return (RET_SUCCESS);
162			}
163
164			/*
165			* mpool_get
166			* Get a page.
167			*/
168			void *
169			mpool_get(MPOOL *mp, pgno_t pgno,
170			u_int flags) /* XXX not used? */
171			{
172			struct _hqh *head;
173			BKT *bp;
174			off_t off;
175			int nr;
176
177			#ifdef STATISTICS
178			++mp->pageget;
179			#endif
180
181			/* Check for a page that is cached. */
182			if ((bp = mpool_look(mp, pgno)) != NULL) {
183			#ifdef DEBUG
184			if (!(flags & MPOOL_IGNOREPIN) && bp->flags & MPOOL_PINNED) {
185			(void)fprintf(stderr,
186			"mpool_get: page %d already pinned\n", bp->pgno);
187			abort();
188			}
189			#endif
190			/*
191			* Move the page to the head of the hash chain and the tail
192			* of the lru chain.
193			*/
194			head = &mp->hqh[HASHKEY(bp->pgno)];
195			TAILQ_REMOVE(head, bp, hq);
196			TAILQ_INSERT_HEAD(head, bp, hq);
197			TAILQ_REMOVE(&mp->lqh, bp, q);
198			TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
199
200			/* Return a pinned page. */
201			bp->flags \|= MPOOL_PINNED;
202			return (bp->page);
203			}
204
205			/* Get a page from the cache. */
206			if ((bp = mpool_bkt(mp)) == NULL)
207			return (NULL);
208
209			/* Read in the contents. */
210			off = mp->pagesize * pgno;
211			if ((nr = pread(mp->fd, bp->page, mp->pagesize, off)) != mp->pagesize) {
212			switch (nr) {
213			case -1:
214			/* errno is set for us by pread(). */
215			free(bp);
216			mp->curcache--;
217			return (NULL);
218			case 0:
219			/*
220			* A zero-length read means you need to create a
221			* new page.
222			*/
223			memset(bp->page, 0, mp->pagesize);
224			break;
225			default:
226			/* A partial read is definitely bad. */
227			free(bp);
228			mp->curcache--;
229			errno = EINVAL;
230			return (NULL);
231			}
232			}
233			#ifdef STATISTICS
234			++mp->pageread;
235			#endif
236
237			/* Set the page number, pin the page. */
238			bp->pgno = pgno;
239			if (!(flags & MPOOL_IGNOREPIN))
240			bp->flags = MPOOL_PINNED;
241			bp->flags \|= MPOOL_INUSE;
242
243			/*
244			* Add the page to the head of the hash chain and the tail
245			* of the lru chain.
246			*/
247			head = &mp->hqh[HASHKEY(bp->pgno)];
248			TAILQ_INSERT_HEAD(head, bp, hq);
249			TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
250
251			/* Run through the user's filter. */
252			if (mp->pgin != NULL)
253			(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
254
255			return (bp->page);
256			}
257
258			/*
259			* mpool_put
260			* Return a page.
261			*/
262			int
263			mpool_put(MPOOL mp, void page, u_int flags)
264			{
265			BKT *bp;
266
267			#ifdef STATISTICS
268			++mp->pageput;
269			#endif
270			bp = (BKT )((char )page - sizeof(BKT));
271			#ifdef DEBUG
272			if (!(bp->flags & MPOOL_PINNED)) {
273			(void)fprintf(stderr,
274			"mpool_put: page %d not pinned\n", bp->pgno);
275			abort();
276			}
277			#endif
278			bp->flags &= ~MPOOL_PINNED;
279			if (flags & MPOOL_DIRTY)
280			bp->flags \|= flags & MPOOL_DIRTY;
281			return (RET_SUCCESS);
282			}
283
284			/*
285			* mpool_close
286			* Close the buffer pool.
287			*/
288			int
289			mpool_close(MPOOL *mp)
290			{
291			BKT *bp;
292
293			/* Free up any space allocated to the lru pages. */
294			while ((bp = TAILQ_FIRST(&mp->lqh))) {
295			TAILQ_REMOVE(&mp->lqh, bp, q);
296			free(bp);
297			}
298
299			/* Free the MPOOL cookie. */
300			free(mp);
301			return (RET_SUCCESS);
302			}
303
304			/*
305			* mpool_sync
306			* Sync the pool to disk.
307			*/
308			int
309			mpool_sync(MPOOL *mp)
310			{
311			BKT *bp;
312
313			/* Walk the lru chain, flushing any dirty pages to disk. */
314			TAILQ_FOREACH(bp, &mp->lqh, q)
315			if (bp->flags & MPOOL_DIRTY &&
316			mpool_write(mp, bp) == RET_ERROR)
317			return (RET_ERROR);
318
319			/* Sync the file descriptor. */
320			return (fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
321			}
322
323			/*
324			* mpool_bkt
325			* Get a page from the cache (or create one).
326			*/
327			static BKT *
328			mpool_bkt(MPOOL *mp)
329			{
330			struct _hqh *head;
331			BKT *bp;
332
333			/* If under the max cached, always create a new page. */
334			if (mp->curcache < mp->maxcache)
335			goto new;
336
337			/*
338			* If the cache is max'd out, walk the lru list for a buffer we
339			* can flush. If we find one, write it (if necessary) and take it
340			* off any lists. If we don't find anything we grow the cache anyway.
341			* The cache never shrinks.
342			*/
343			TAILQ_FOREACH(bp, &mp->lqh, q)
344			if (!(bp->flags & MPOOL_PINNED)) {
345			/* Flush if dirty. */
346			if (bp->flags & MPOOL_DIRTY &&
347			mpool_write(mp, bp) == RET_ERROR)
348			return (NULL);
349			#ifdef STATISTICS
350			++mp->pageflush;
351			#endif
352			/* Remove from the hash and lru queues. */
353			head = &mp->hqh[HASHKEY(bp->pgno)];
354			TAILQ_REMOVE(head, bp, hq);
355			TAILQ_REMOVE(&mp->lqh, bp, q);
356			#ifdef DEBUG
357			{ void *spage;
358			spage = bp->page;
359			memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
360			bp->page = spage;
361			}
362			#endif
363			bp->flags = 0;
364			return (bp);
365			}
366
367			new: if ((bp = (BKT *)malloc(sizeof(BKT) + mp->pagesize)) == NULL)
368			return (NULL);
369			#ifdef STATISTICS
370			++mp->pagealloc;
371			#endif
372			memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
373			bp->page = (char *)bp + sizeof(BKT);
374			bp->flags = 0;
375			++mp->curcache;
376			return (bp);
377			}
378
379			/*
380			* mpool_write
381			* Write a page to disk.
382			*/
383			static int
384			mpool_write(MPOOL mp, BKT bp)
385			{
386			off_t off;
387
388			#ifdef STATISTICS
389			++mp->pagewrite;
390			#endif
391
392			/* Run through the user's filter. */
393			if (mp->pgout)
394			(mp->pgout)(mp->pgcookie, bp->pgno, bp->page);
395
396			off = mp->pagesize * bp->pgno;
397			if (pwrite(mp->fd, bp->page, mp->pagesize, off) != mp->pagesize)
398			return (RET_ERROR);
399
400			/*
401			* Re-run through the input filter since this page may soon be
402			* accessed via the cache, and whatever the user's output filter
403			* did may screw things up if we don't let the input filter
404			* restore the in-core copy.
405			*/
406			if (mp->pgin)
407			(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
408
409			bp->flags &= ~MPOOL_DIRTY;
410			return (RET_SUCCESS);
411			}
412
413			/*
414			* mpool_look
415			* Lookup a page in the cache.
416			*/
417			static BKT *
418			mpool_look(MPOOL *mp, pgno_t pgno)
419			{
420			struct _hqh *head;
421			BKT *bp;
422
423			head = &mp->hqh[HASHKEY(pgno)];
424			TAILQ_FOREACH(bp, head, hq)
425			if ((bp->pgno == pgno) &&
426			((bp->flags & MPOOL_INUSE) == MPOOL_INUSE)) {
427			#ifdef STATISTICS
428			++mp->cachehit;
429			#endif
430			return (bp);
431			}
432			#ifdef STATISTICS
433			++mp->cachemiss;
434			#endif
435			return (NULL);
436			}
437
438			#ifdef STATISTICS
439			/*
440			* mpool_stat
441			* Print out cache statistics.
442			*/
443			void
444			mpool_stat(MPOOL *mp)
445			{
446			BKT *bp;
447			int cnt;
448			char *sep;
449
450			(void)fprintf(stderr, "%lu pages in the file\n", mp->npages);
451			(void)fprintf(stderr,
452			"page size %lu, cacheing %lu pages of %lu page max cache\n",
453			mp->pagesize, mp->curcache, mp->maxcache);
454			(void)fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n",
455			mp->pageput, mp->pageget, mp->pagenew);
456			(void)fprintf(stderr, "%lu page allocs, %lu page flushes\n",
457			mp->pagealloc, mp->pageflush);
458			if (mp->cachehit + mp->cachemiss)
459			(void)fprintf(stderr,
460			"%.0f%% cache hit rate (%lu hits, %lu misses)\n",
461			((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
462			* 100, mp->cachehit, mp->cachemiss);
463			(void)fprintf(stderr, "%lu page reads, %lu page writes\n",
464			mp->pageread, mp->pagewrite);
465
466			sep = "";
467			cnt = 0;
468			TAILQ_FOREACH(bp, &mp->lqh, q) {
469			(void)fprintf(stderr, "%s%d", sep, bp->pgno);
470			if (bp->flags & MPOOL_DIRTY)
471			(void)fprintf(stderr, "d");
472			if (bp->flags & MPOOL_PINNED)
473			(void)fprintf(stderr, "P");
474			if (++cnt == 10) {
475			sep = "\n";
476			cnt = 0;
477			} else
478			sep = ", ";
479
480			}
481			(void)fprintf(stderr, "\n");
482			}
483			#endif