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mdbx: MDB_PAGEPERTURB.

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Change-Id: Id78304cb1f5caa3231e69388f6ce29a431e39976
This commit is contained in:
Leo Yuriev 2016-02-09 09:23:16 +03:00
parent 0a8e59c314
commit c9642d1082
2 changed files with 34 additions and 4 deletions
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4
lmdb.h
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@ -304,8 +304,10 @@ typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *rel
#define MDB_LIFORECLAIM 0x4000000
#endif /* MDBX_MODE_ENABLED */
/** make a steady-sync only on close and explicit env-sync */
/** make a steady-sync only on close and explicit env-sync */
#define MDB_UTTERLY_NOSYNC (MDB_NOSYNC|MDB_MAPASYNC)
/** debuging option, fill/perturb released pages */
#define MDB_PAGEPERTURB 0x8000000
/** @} */
/** @defgroup mdb_dbi_open Database Flags

34
mdb.c
View File

@ -1575,6 +1575,28 @@ mdb_dlist_free(MDB_txn *txn)
dl[0].mid = 0;
}
__cold static void
mdb_kill_page(MDB_env *env, MDB_page *mp)
{
const unsigned off = offsetof(MDB_page, mp_pb);
if (env->me_flags & MDB_WRITEMAP) {
memset(&mp->mp_pb, 0x6F /* 'o', 111 */, env->me_psize - off);
} else {
if (unlikely(env->me_dpages == 0)) {
mdb_page_free(env, mdb_page_malloc(env->me_txn0, 1));
assert(env->me_dpages != 0);
}
struct iovec iov[1];
iov[0].iov_len = env->me_psize - off;
iov[0].iov_base = ((char*) env->me_dpages) + off;
memset(iov[0].iov_base, 0x6F /* 'o', 111 */, iov[0].iov_len);
int rc = pwritev(env->me_fd, iov, 1, env->me_psize * mp->mp_pgno + off);
assert(rc == iov[0].iov_len);
(void) rc;
}
}
/** Loosen or free a single page.
* Saves single pages to a list for future reuse
* in this same txn. It has been pulled from the freeDB
@ -1592,6 +1614,10 @@ mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
pgno_t pgno = mp->mp_pgno;
MDB_txn *txn = mc->mc_txn;
if (unlikely(txn->mt_env->me_flags & MDB_PAGEPERTURB)) {
mdb_kill_page(txn->mt_env, mp);
}
if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
if (txn->mt_parent) {
MDB_ID2 *dl = txn->mt_u.dirty_list;
@ -2332,7 +2358,7 @@ done:
}
#if LDAP_MEMORY_DEBUG > 0
memset(np, 111, env->me_psize * num);
memset(np, 0x71 /* 'q', 113 */, env->me_psize * num);
#endif
VALGRIND_MAKE_MEM_UNDEFINED(np, env->me_psize * num);
@ -4305,7 +4331,9 @@ mdb_env_map(MDB_env *env, void *addr)
#endif
#ifdef MADV_DONTDUMP
(void) madvise(env->me_map, env->me_mapsize, MADV_DONTDUMP);
if (! (flags & MDB_PAGEPERTURB)) {
(void) madvise(env->me_map, env->me_mapsize, MADV_DONTDUMP);
}
#endif
/* Can happen because the address argument to mmap() is just a
@ -4796,7 +4824,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
* environment and re-opening it with the new flags.
*/
#define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC| \
MDB_NOMEMINIT|MDB_COALESCE)
MDB_NOMEMINIT|MDB_COALESCE|MDB_PAGEPERTURB)
#define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
MDB_WRITEMAP|MDB_NOTLS|MDB_NORDAHEAD|MDB_LIFORECLAIM)