lmdb: Move code into mdb_txn_end(). Was mdb_txn_reset0.

Side effects:
* Clean txn up a bit even before freeing it.
* Tweak DEBUG output at txn end. Add DEBUG after commit(writer).

Change-Id: Ia9905257893923bb14cdf33b60b6387af3121f81
This commit is contained in:
Hallvard Furuseth 2015-07-19 21:30:12 +02:00 committed by Leo Yuriev
parent 23af429b3f
commit e3c8fa8eba

106
mdb.c
View File

@ -1116,6 +1116,19 @@ static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
static int mdb_page_touch(MDB_cursor *mc);
#define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
"reset-tmp", "fail-begin", "fail-beginchild"}
enum {
/* mdb_txn_end operation number, for logging */
MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
};
#define MDB_END_OPMASK 0x0F /**< mask for #mdb_txn_end() operation number */
#define MDB_END_UPDATE 0x10 /**< update env state (DBIs) */
#define MDB_END_FREE 0x20 /**< free txn unless it is #MDB_env.%me_txn0 */
#define MDB_END_SLOT MDB_NOTLS /**< release any reader slot if #MDB_NOTLS */
static void mdb_txn_end(MDB_txn *txn, unsigned mode);
static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
static int mdb_page_search_root(MDB_cursor *mc,
MDB_val *key, int modify);
@ -2676,9 +2689,6 @@ mdb_cursors_close(MDB_txn *txn, unsigned merge)
}
}
static void
mdb_txn_reset0(MDB_txn *txn, const char *act);
/** Set or check a pid lock. Set returns 0 on success.
* Check returns 0 if the process is certainly dead, nonzero if it may
* be alive (the lock exists or an error happened so we do not know).
@ -2833,13 +2843,8 @@ mdb_txn_renew0(MDB_txn *txn)
txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
txn->mt_dbflags[FREE_DBI] = DB_VALID;
if (env->me_maxpg < txn->mt_next_pgno) {
mdb_txn_reset0(txn, "renew0-mapfail");
if (new_notls) {
txn->mt_u.reader->mr_pid = 0;
txn->mt_u.reader = NULL;
mdb_coherent_barrier();
}
if (unlikely(env->me_maxpg < txn->mt_next_pgno)) {
mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
return MDB_MAP_RESIZED;
}
@ -2951,16 +2956,16 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned flags, MDB_txn **ret)
else
rc = ENOMEM;
}
if (!rc)
if (likely(!rc))
rc = mdb_cursor_shadow(parent, txn);
if (rc)
mdb_txn_reset0(txn, "beginchild-fail");
if (unlikely(rc))
mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
} else { /* MDB_RDONLY */
txn->mt_dbiseqs = env->me_dbiseqs;
renew:
rc = mdb_txn_renew0(txn);
}
if (rc) {
if (unlikely(rc)) {
if (txn != env->me_txn0)
free(txn);
} else {
@ -3038,35 +3043,45 @@ mdb_txn_straggler(MDB_txn *txn, int *percent)
return (0 > (long) lag) ? ~0u >> 1: lag;
}
/** Common code for #mdb_txn_reset() and #mdb_txn_abort().
/** End a transaction, except successful commit of a nested transaction.
* May be called twice for readonly txns: First reset it, then abort.
* @param[in] txn the transaction handle to reset
* @param[in] act why the transaction is being reset
* @param[in] txn the transaction handle to end
* @param[in] mode why and how to end the transaction
*/
static void
mdb_txn_reset0(MDB_txn *txn, const char *act_)
mdb_txn_end(MDB_txn *txn, unsigned mode)
{
MDB_env *env = txn->mt_env;
#if MDB_DEBUG
static const char *const names[] = MDB_END_NAMES;
#endif
/* Close any DBI handles opened in this txn */
mdb_dbis_update(txn, 0);
/* Export or close DBI handles opened in this txn */
mdb_dbis_update(txn, mode & MDB_END_UPDATE);
mdb_debug("%s txn %zu%c %p on mdbenv %p, root page %zu",
act_, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
names[mode & MDB_END_OPMASK],
txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
(void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root);
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
if (txn->mt_u.reader) {
txn->mt_u.reader->mr_txnid = (txnid_t)-1;
if (!(env->me_flags & MDB_NOTLS))
if (!(env->me_flags & MDB_NOTLS)) {
txn->mt_u.reader = NULL; /* txn does not own reader */
} else if (mode & MDB_END_SLOT) {
txn->mt_u.reader->mr_pid = 0;
txn->mt_u.reader = NULL;
} /* else txn owns the slot until it does MDB_END_SLOT */
}
mdb_coherent_barrier();
txn->mt_numdbs = 0; /* close nothing if called again */
txn->mt_dbxs = NULL; /* mark txn as reset */
} else {
pgno_t *pghead = env->me_pghead;
mdb_cursors_close(txn, 0);
if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
mdb_cursors_close(txn, 0);
if (!(env->me_flags & MDB_WRITEMAP)) {
mdb_dlist_free(txn);
}
@ -3087,6 +3102,8 @@ mdb_txn_reset0(MDB_txn *txn, const char *act_)
env->me_pglast = 0;
env->me_txn = NULL;
mode = 0; /* txn == env->me_txn0, do not free() it */
/* The writer mutex was locked in mdb_txn_begin. */
mdb_mutex_unlock(env, MDB_MUTEX(env, w));
} else {
@ -3099,6 +3116,9 @@ mdb_txn_reset0(MDB_txn *txn, const char *act_)
mdb_midl_free(pghead);
}
if (mode & MDB_END_FREE)
free(txn);
}
void
@ -3111,7 +3131,7 @@ mdb_txn_reset(MDB_txn *txn)
if (!(txn->mt_flags & MDB_TXN_RDONLY))
return;
mdb_txn_reset0(txn, "reset");
mdb_txn_end(txn, MDB_END_RESET);
}
void
@ -3123,15 +3143,7 @@ mdb_txn_abort(MDB_txn *txn)
if (txn->mt_child)
mdb_txn_abort(txn->mt_child);
mdb_txn_reset0(txn, "abort");
/* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader) {
txn->mt_u.reader->mr_pid = 0;
mdb_coherent_barrier();
}
if (txn != txn->mt_env->me_txn0)
free(txn);
mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
}
/** Save the freelist as of this transaction to the freeDB.
@ -3571,12 +3583,15 @@ int
mdb_txn_commit(MDB_txn *txn)
{
int rc;
unsigned i;
unsigned i, end_mode;
MDB_env *env;
if (unlikely(txn == NULL))
return EINVAL;
/* mdb_txn_end() mode for a commit which writes nothing */
end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
if (txn->mt_child) {
rc = mdb_txn_commit(txn->mt_child);
txn->mt_child = NULL;
@ -3584,11 +3599,10 @@ mdb_txn_commit(MDB_txn *txn)
goto fail;
}
env = txn->mt_env;
if (unlikely(F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))) {
mdb_dbis_update(txn, 1);
txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
mdb_txn_abort(txn);
return MDB_SUCCESS;
goto done;
}
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
@ -3769,7 +3783,6 @@ mdb_txn_commit(MDB_txn *txn)
mdb_midl_free(env->me_pghead);
env->me_pghead = NULL;
mdb_midl_shrink(&txn->mt_free_pgs);
env->me_free_pgs = txn->mt_free_pgs;
if (mdb_audit_enabled())
mdb_audit(txn);
@ -3787,19 +3800,10 @@ mdb_txn_commit(MDB_txn *txn)
}
if (unlikely(rc != MDB_SUCCESS))
goto fail;
/* Free P_LOOSE pages left behind in dirty_list */
if (!(env->me_flags & MDB_WRITEMAP))
mdb_dlist_free(txn);
end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
done:
env->me_pglast = 0;
env->me_txn = NULL;
mdb_dbis_update(txn, 1);
mdb_mutex_unlock(env, MDB_MUTEX(env, w));
if (txn != env->me_txn0)
free(txn);
mdb_txn_end(txn, end_mode);
return MDB_SUCCESS;
fail:
@ -8804,7 +8808,7 @@ mdb_env_copyfd0(MDB_env *env, HANDLE fd)
return rc;
/* We must start the actual read txn after blocking writers */
mdb_txn_reset0(txn, "reset-stage1");
mdb_txn_end(txn, MDB_END_RESET_TMP);
/* Temporarily block writers until we snapshot the meta pages */
wmutex = MDB_MUTEX(env, w);