Drop me_toggle, unused

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 38825e9..983c75c 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -521,11 +521,6 @@ typedef struct MDB_txbody {
                 *      when readers release their slots.
                 */
        unsigned        mtb_numreaders;
-               /**     The ID of the most recent meta page in the database.
-                *      This is recorded here only for convenience; the value can always
-                *      be determined by reading the main database meta pages.
-                */
-       uint32_t        mtb_me_toggle;
 } MDB_txbody;
 
        /** The actual reader table definition. */
@@ -538,7 +533,6 @@ typedef struct MDB_txninfo {
 #define mti_rmname     mt1.mtb.mtb_rmname
 #define mti_txnid      mt1.mtb.mtb_txnid
 #define mti_numreaders mt1.mtb.mtb_numreaders
-#define mti_me_toggle  mt1.mtb.mtb_me_toggle
                char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
        } mt1;
        union {
@@ -1575,8 +1569,9 @@ mdb_txn_renew0(MDB_txn *txn)
                        r = &env->me_txns->mti_readers[i];
                        pthread_setspecific(env->me_txkey, r);
                }
-               txn->mt_toggle = env->me_txns->mti_me_toggle;
                txn->mt_txnid = env->me_txns->mti_txnid;
+               txn->mt_toggle = txn->mt_txnid & 1;
+               txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
                /* This happens if a different process was the
                 * last writer to the DB.
                 */
@@ -1588,6 +1583,8 @@ mdb_txn_renew0(MDB_txn *txn)
                LOCK_MUTEX_W(env);
 
                txn->mt_txnid = env->me_txns->mti_txnid;
+               txn->mt_toggle = txn->mt_txnid & 1;
+               txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
                if (env->me_wtxnid < txn->mt_txnid)
                        mt_dbflag = DB_STALE;
                txn->mt_txnid++;
@@ -1595,14 +1592,12 @@ mdb_txn_renew0(MDB_txn *txn)
                if (txn->mt_txnid == mdb_debug_start)
                        mdb_debug = 1;
 #endif
-               txn->mt_toggle = env->me_txns->mti_me_toggle;
                txn->mt_u.dirty_list = env->me_dirty_list;
                txn->mt_u.dirty_list[0].mid = 0;
                txn->mt_free_pgs = env->me_free_pgs;
                txn->mt_free_pgs[0] = 0;
                env->me_txn = txn;
        }
-       txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
 
        /* Copy the DB arrays */
        LAZY_RWLOCK_RDLOCK(&env->me_dblock);
@@ -2394,7 +2389,6 @@ mdb_env_write_meta(MDB_txn *txn)
         * how stale their view of these values is.
         */
        LAZY_MUTEX_LOCK(&env->me_txns->mti_mutex);
-       txn->mt_env->me_txns->mti_me_toggle = toggle;
        txn->mt_env->me_txns->mti_txnid = txn->mt_txnid;
        LAZY_MUTEX_UNLOCK(&env->me_txns->mti_mutex);
 
@@ -2598,7 +2592,6 @@ mdb_env_share_locks(MDB_env *env)
 {
        int toggle = mdb_env_pick_meta(env);
 
-       env->me_txns->mti_me_toggle = toggle;
        env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
 
 #ifdef _WIN32
@@ -2916,7 +2909,6 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
                env->me_txns->mti_magic = MDB_MAGIC;
                env->me_txns->mti_txnid = 0;
                env->me_txns->mti_numreaders = 0;
-               env->me_txns->mti_me_toggle = 0;
 
        } else {
                if (env->me_txns->mti_magic != MDB_MAGIC) {