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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998, 1999
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char sccsid[] = "@(#)mp_method.c 11.2 (Sleepycat) 10/6/99";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#endif
#include "db_int.h"
#include "db_shash.h"
#include "mp.h"
static int CDB___memp_set_cachesize __P((DB_ENV *, u_int32_t, u_int32_t, int));
static int CDB___memp_set_mp_mmapsize __P((DB_ENV *, size_t));
/*
* CDB___memp_dbenv_create --
* Mpool specific creation of the DB_ENV structure.
*
* PUBLIC: void CDB___memp_dbenv_create __P((DB_ENV *));
*/
void
CDB___memp_dbenv_create(dbenv)
DB_ENV *dbenv;
{
/*
* We default to 32 8K pages. We don't default to a flat 256K, because
* some systems require significantly more memory to hold 32 pages than
* others. For example, HP-UX with POSIX pthreads needs 88 bytes for
* a POSIX pthread mutex and almost 200 bytes per buffer header, while
* Solaris needs 24 and 52 bytes for the same structures.
*/
dbenv->mp_bytes = 32 * ((8 * 1024) + sizeof(BH));
dbenv->mp_ncache = 1;
dbenv->set_mp_mmapsize = CDB___memp_set_mp_mmapsize;
dbenv->set_cachesize = CDB___memp_set_cachesize;
}
/*
* CDB___memp_set_cachesize --
* Initialize the cache size.
*/
static int
CDB___memp_set_cachesize(dbenv, gbytes, bytes, ncache)
DB_ENV *dbenv;
u_int32_t gbytes, bytes;
int ncache;
{
ENV_ILLEGAL_AFTER_OPEN(dbenv, "set_cachesize");
dbenv->mp_gbytes = gbytes + bytes / GIGABYTE;
dbenv->mp_bytes = bytes % GIGABYTE;
dbenv->mp_ncache = ncache == 0 ? 1 : ncache;
/*
* If the application requested less than 500Mb, increase the
* cachesize by 25% to account for our overhead. (I'm guessing
* that caches over 500Mb are specifically sized, i.e., it's
* a large server and the application actually knows how much
* memory is available.)
*
* There is a minimum cache size, regardless.
*/
if (dbenv->mp_gbytes == 0) {
if (dbenv->mp_bytes < 500 * MEGABYTE)
dbenv->mp_bytes += dbenv->mp_bytes / 4;
if (dbenv->mp_bytes < DB_CACHESIZE_MIN)
dbenv->mp_bytes = DB_CACHESIZE_MIN;
}
return (0);
}
/*
* CDB___memp_set_mp_mmapsize --
* Set the maximum mapped file size.
*/
static int
CDB___memp_set_mp_mmapsize(dbenv, mp_mmapsize )
DB_ENV *dbenv;
size_t mp_mmapsize;
{
dbenv->mp_mmapsize = mp_mmapsize;
return (0);
}
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