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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2002
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: mp_fput.c,v 1.1.1.1 2003/11/20 22:13:36 toshok Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#endif
#include "db_int.h"
#include "dbinc/db_shash.h"
#include "dbinc/mp.h"
/*
* __memp_fput --
* Mpool file put function.
*
* PUBLIC: int __memp_fput __P((DB_MPOOLFILE *, void *, u_int32_t));
*/
int
__memp_fput(dbmfp, pgaddr, flags)
DB_MPOOLFILE *dbmfp;
void *pgaddr;
u_int32_t flags;
{
BH *argbhp, *bhp, *prev;
DB_ENV *dbenv;
DB_MPOOL *dbmp;
DB_MPOOL_HASH *hp;
MPOOL *c_mp;
u_int32_t n_cache;
int adjust, ret;
dbmp = dbmfp->dbmp;
dbenv = dbmp->dbenv;
PANIC_CHECK(dbenv);
/* Validate arguments. */
if (flags) {
if ((ret = __db_fchk(dbenv, "memp_fput", flags,
DB_MPOOL_CLEAN | DB_MPOOL_DIRTY | DB_MPOOL_DISCARD)) != 0)
return (ret);
if ((ret = __db_fcchk(dbenv, "memp_fput",
flags, DB_MPOOL_CLEAN, DB_MPOOL_DIRTY)) != 0)
return (ret);
if (LF_ISSET(DB_MPOOL_DIRTY) && F_ISSET(dbmfp, MP_READONLY)) {
__db_err(dbenv,
"%s: dirty flag set for readonly file page",
__memp_fn(dbmfp));
return (EACCES);
}
}
/*
* If we're mapping the file, there's nothing to do. Because we can
* stop mapping the file at any time, we have to check on each buffer
* to see if the address we gave the application was part of the map
* region.
*/
if (dbmfp->addr != NULL && pgaddr >= dbmfp->addr &&
(u_int8_t *)pgaddr <= (u_int8_t *)dbmfp->addr + dbmfp->len)
return (0);
#ifdef DIAGNOSTIC
/*
* Decrement the per-file pinned buffer count (mapped pages aren't
* counted).
*/
R_LOCK(dbenv, dbmp->reginfo);
if (dbmfp->pinref == 0) {
ret = EINVAL;
__db_err(dbenv,
"%s: more pages returned than retrieved", __memp_fn(dbmfp));
} else {
ret = 0;
--dbmfp->pinref;
}
R_UNLOCK(dbenv, dbmp->reginfo);
if (ret != 0)
return (ret);
#endif
/* Convert a page address to a buffer header and hash bucket. */
bhp = (BH *)((u_int8_t *)pgaddr - SSZA(BH, buf));
n_cache = NCACHE(dbmp->reginfo[0].primary, bhp->mf_offset, bhp->pgno);
c_mp = dbmp->reginfo[n_cache].primary;
hp = R_ADDR(&dbmp->reginfo[n_cache], c_mp->htab);
hp = &hp[NBUCKET(c_mp, bhp->mf_offset, bhp->pgno)];
MUTEX_LOCK(dbenv, &hp->hash_mutex);
/* Set/clear the page bits. */
if (LF_ISSET(DB_MPOOL_CLEAN) &&
F_ISSET(bhp, BH_DIRTY) && !F_ISSET(bhp, BH_DIRTY_CREATE)) {
DB_ASSERT(hp->hash_page_dirty != 0);
--hp->hash_page_dirty;
F_CLR(bhp, BH_DIRTY);
}
if (LF_ISSET(DB_MPOOL_DIRTY) && !F_ISSET(bhp, BH_DIRTY)) {
++hp->hash_page_dirty;
F_SET(bhp, BH_DIRTY);
}
if (LF_ISSET(DB_MPOOL_DISCARD))
F_SET(bhp, BH_DISCARD);
/*
* Check for a reference count going to zero. This can happen if the
* application returns a page twice.
*/
if (bhp->ref == 0) {
__db_err(dbenv, "%s: page %lu: unpinned page returned",
__memp_fn(dbmfp), (u_long)bhp->pgno);
MUTEX_UNLOCK(dbenv, &hp->hash_mutex);
return (EINVAL);
}
/*
* If more than one reference to the page or a reference other than a
* thread waiting to flush the buffer to disk, we're done. Ignore the
* discard flags (for now) and leave the buffer's priority alone.
*/
if (--bhp->ref > 1 || (bhp->ref == 1 && !F_ISSET(bhp, BH_LOCKED))) {
MUTEX_UNLOCK(dbenv, &hp->hash_mutex);
return (0);
}
/* Update priority values. */
if (F_ISSET(bhp, BH_DISCARD) ||
dbmfp->mfp->priority == MPOOL_PRI_VERY_LOW)
bhp->priority = 0;
else {
/*
* We don't lock the LRU counter or the stat.st_pages field, if
* we get garbage (which won't happen on a 32-bit machine), it
* only means a buffer has the wrong priority.
*/
bhp->priority = c_mp->lru_count;
adjust = 0;
if (dbmfp->mfp->priority != 0)
adjust =
(int)c_mp->stat.st_pages / dbmfp->mfp->priority;
if (F_ISSET(bhp, BH_DIRTY))
adjust += c_mp->stat.st_pages / MPOOL_PRI_DIRTY;
if (adjust > 0) {
if (UINT32_T_MAX - bhp->priority <= (u_int32_t)adjust)
bhp->priority += adjust;
} else if (adjust < 0)
if (bhp->priority > (u_int32_t)-adjust)
bhp->priority += adjust;
}
/*
* Buffers on hash buckets are sorted by priority -- move the buffer
* to the correct position in the list.
*/
argbhp = bhp;
SH_TAILQ_REMOVE(&hp->hash_bucket, argbhp, hq, __bh);
prev = NULL;
for (bhp = SH_TAILQ_FIRST(&hp->hash_bucket, __bh);
bhp != NULL; prev = bhp, bhp = SH_TAILQ_NEXT(bhp, hq, __bh))
if (bhp->priority > argbhp->priority)
break;
if (prev == NULL)
SH_TAILQ_INSERT_HEAD(&hp->hash_bucket, argbhp, hq, __bh);
else
SH_TAILQ_INSERT_AFTER(&hp->hash_bucket, prev, argbhp, hq, __bh);
/* Reset the hash bucket's priority. */
hp->hash_priority = SH_TAILQ_FIRST(&hp->hash_bucket, __bh)->priority;
#ifdef DIAGNOSTIC
__memp_check_order(hp);
#endif
/*
* The sync code has a separate counter for buffers on which it waits.
* It reads that value without holding a lock so we update it as the
* last thing we do. Once that value goes to 0, we won't see another
* reference to that buffer being returned to the cache until the sync
* code has finished, so we're safe as long as we don't let the value
* go to 0 before we finish with the buffer.
*/
if (F_ISSET(argbhp, BH_LOCKED) && argbhp->ref_sync != 0)
--argbhp->ref_sync;
MUTEX_UNLOCK(dbenv, &hp->hash_mutex);
return (0);
}
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