mp_method.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:4k
- /*-
- * 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_method.c,v 11.29 2002/03/27 04:32:27 bostic Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #ifdef HAVE_RPC
- #include <rpc/rpc.h>
- #endif
- #endif
- #include "db_int.h"
- #include "dbinc/db_shash.h"
- #include "dbinc/mp.h"
- #ifdef HAVE_RPC
- #include "dbinc_auto/db_server.h"
- #include "dbinc_auto/rpc_client_ext.h"
- #endif
- static int __memp_set_cachesize __P((DB_ENV *, u_int32_t, u_int32_t, int));
- static int __memp_set_mp_mmapsize __P((DB_ENV *, size_t));
- /*
- * __memp_dbenv_create --
- * Mpool specific creation of the DB_ENV structure.
- *
- * PUBLIC: void __memp_dbenv_create __P((DB_ENV *));
- */
- void
- __memp_dbenv_create(dbenv)
- DB_ENV *dbenv;
- {
- /*
- * !!!
- * Our caller has not yet had the opportunity to reset the panic
- * state or turn off mutex locking, and so we can neither check
- * the panic state or acquire a mutex in the DB_ENV create path.
- *
- * 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. The minimum
- * number of hash buckets is 37. These contain a mutex also.
- */
- dbenv->mp_bytes =
- 32 * ((8 * 1024) + sizeof(BH)) + 37 * sizeof(DB_MPOOL_HASH);
- dbenv->mp_ncache = 1;
- #ifdef HAVE_RPC
- if (F_ISSET(dbenv, DB_ENV_RPCCLIENT)) {
- dbenv->set_cachesize = __dbcl_env_cachesize;
- dbenv->set_mp_mmapsize = __dbcl_set_mp_mmapsize;
- dbenv->memp_dump_region = NULL;
- dbenv->memp_fcreate = __dbcl_memp_fcreate;
- dbenv->memp_nameop = NULL;
- dbenv->memp_register = __dbcl_memp_register;
- dbenv->memp_stat = __dbcl_memp_stat;
- dbenv->memp_sync = __dbcl_memp_sync;
- dbenv->memp_trickle = __dbcl_memp_trickle;
- } else
- #endif
- {
- dbenv->set_cachesize = __memp_set_cachesize;
- dbenv->set_mp_mmapsize = __memp_set_mp_mmapsize;
- dbenv->memp_dump_region = __memp_dump_region;
- dbenv->memp_fcreate = __memp_fcreate;
- dbenv->memp_nameop = __memp_nameop;
- dbenv->memp_register = __memp_register;
- dbenv->memp_stat = __memp_stat;
- dbenv->memp_sync = __memp_sync;
- dbenv->memp_trickle = __memp_trickle;
- }
- }
- /*
- * __memp_set_cachesize --
- * Initialize the cache size.
- */
- static int
- __memp_set_cachesize(dbenv, gbytes, bytes, ncache)
- DB_ENV *dbenv;
- u_int32_t gbytes, bytes;
- int ncache;
- {
- ENV_ILLEGAL_AFTER_OPEN(dbenv, "set_cachesize");
- /* Normalize the values. */
- if (ncache == 0)
- ncache = 1;
- /*
- * You can only store 4GB-1 in an unsigned 32-bit value, so correct for
- * applications that specify 4GB cache sizes -- we know what they meant.
- */
- if (gbytes / ncache == 4 && bytes == 0) {
- --gbytes;
- bytes = GIGABYTE - 1;
- } else {
- gbytes += bytes / GIGABYTE;
- bytes %= GIGABYTE;
- }
- /* Avoid too-large cache sizes, they result in a region size of zero. */
- if (gbytes / ncache > 4 || (gbytes / ncache == 4 && bytes != 0)) {
- __db_err(dbenv, "individual cache size too large");
- return (EINVAL);
- }
- /*
- * If the application requested less than 500Mb, increase the cachesize
- * by 25% and factor in the size of the hash buckets to account for our
- * overhead. (I'm guessing caches over 500Mb are specifically sized,
- * that is, it's a large server and the application actually knows how
- * much memory is available. We only document the 25% overhead number,
- * not the hash buckets, but I don't see a reason to confuse the issue,
- * it shouldn't matter to an application.)
- *
- * There is a minimum cache size, regardless.
- */
- if (gbytes == 0) {
- if (bytes < 500 * MEGABYTE)
- bytes += (bytes / 4) + 37 * sizeof(DB_MPOOL_HASH);
- if (bytes / ncache < DB_CACHESIZE_MIN)
- bytes = ncache * DB_CACHESIZE_MIN;
- }
- dbenv->mp_gbytes = gbytes;
- dbenv->mp_bytes = bytes;
- dbenv->mp_ncache = ncache;
- return (0);
- }
- /*
- * __memp_set_mp_mmapsize --
- * Set the maximum mapped file size.
- */
- static int
- __memp_set_mp_mmapsize(dbenv, mp_mmapsize )
- DB_ENV *dbenv;
- size_t mp_mmapsize;
- {
- dbenv->mp_mmapsize = mp_mmapsize;
- return (0);
- }