Optimize code holding reader mutex

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index cc7471ac4ee6427752cece44bf5a30b36471089f..0ee9f50b361c2ec3c52818c199ecd1ec34d79aa8 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -2119,8 +2119,9 @@ static int
 mdb_txn_renew0(MDB_txn *txn)
 {
        MDB_env *env = txn->mt_env;
+       MDB_txninfo *ti = env->me_txns;
        MDB_meta *meta;
-       unsigned int i;
+       unsigned int i, nr;
        uint16_t x;
        int rc, new_notls = 0;
 
@@ -2129,7 +2130,7 @@ mdb_txn_renew0(MDB_txn *txn)
        txn->mt_dbxs = env->me_dbxs;    /* mostly static anyway */
 
        if (txn->mt_flags & MDB_TXN_RDONLY) {
-               if (!env->me_txns) {
+               if (!ti) {
                        meta = env->me_metas[ mdb_env_pick_meta(env) ];
                        txn->mt_txnid = meta->mm_txnid;
                        txn->mt_u.reader = NULL;
@@ -2153,36 +2154,38 @@ mdb_txn_renew0(MDB_txn *txn)
                                }
 
                                LOCK_MUTEX_R(env);
-                               for (i=0; i<env->me_txns->mti_numreaders; i++)
-                                       if (env->me_txns->mti_readers[i].mr_pid == 0)
+                               nr = ti->mti_numreaders;
+                               for (i=0; i<nr; i++)
+                                       if (ti->mti_readers[i].mr_pid == 0)
                                                break;
                                if (i == env->me_maxreaders) {
                                        UNLOCK_MUTEX_R(env);
                                        return MDB_READERS_FULL;
                                }
-                               env->me_txns->mti_readers[i].mr_pid = pid;
-                               env->me_txns->mti_readers[i].mr_tid = tid;
-                               if (i >= env->me_txns->mti_numreaders)
-                                       env->me_txns->mti_numreaders = i+1;
+                               ti->mti_readers[i].mr_pid = pid;
+                               ti->mti_readers[i].mr_tid = tid;
+                               if (i == nr)
+                                       ti->mti_numreaders = ++nr;
                                /* Save numreaders for un-mutexed mdb_env_close() */
-                               env->me_numreaders = env->me_txns->mti_numreaders;
+                               env->me_numreaders = nr;
                                UNLOCK_MUTEX_R(env);
-                               r = &env->me_txns->mti_readers[i];
+
+                               r = &ti->mti_readers[i];
                                new_notls = (env->me_flags & MDB_NOTLS);
                                if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
                                        r->mr_pid = 0;
                                        return rc;
                                }
                        }
-                       txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
+                       txn->mt_txnid = r->mr_txnid = ti->mti_txnid;
                        txn->mt_u.reader = r;
                        meta = env->me_metas[txn->mt_txnid & 1];
                }
        } else {
-               if (env->me_txns) {
+               if (ti) {
                        LOCK_MUTEX_W(env);
 
-                       txn->mt_txnid = env->me_txns->mti_txnid;
+                       txn->mt_txnid = ti->mti_txnid;
                        meta = env->me_metas[txn->mt_txnid & 1];
                } else {
                        meta = env->me_metas[ mdb_env_pick_meta(env) ];