Moved current_linfo under #ifdef HAVE_REPLICATION

Also set current_linfo under THD::LOCK_thd_data protection to
avoid data race.

Pre-requisite for clean MDEV-18450 solution.

3 files changed, 28 insertions, 21 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index bbba5218989..e2bc6ef1d90 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -644,6 +644,7 @@ THD::THD(my_thread_id id, bool is_wsrep_applier, bool skip_global_sys_var_lock)
    m_tmp_tables_locked(false)
 #ifdef HAVE_REPLICATION
    ,
+   current_linfo(0),
    slave_info(0)
 #endif
 #ifdef WITH_WSREP
@@ -751,7 +752,6 @@ THD::THD(my_thread_id id, bool is_wsrep_applier, bool skip_global_sys_var_lock)
   progress.arena= 0;
   progress.report_to_client= 0;
   progress.max_counter= 0;
-  current_linfo =  0;
   slave_thread = 0;
   connection_name.str= 0;
   connection_name.length= 0;
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 23c51067734..70f0e04efe5 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -3194,12 +3194,6 @@ public:
   /** number of name_const() substitutions, see sp_head.cc:subst_spvars() */
   uint       query_name_consts;
 
-  /*
-    If we do a purge of binary logs, log index info of the threads
-    that are currently reading it needs to be adjusted. To do that
-    each thread that is using LOG_INFO needs to adjust the pointer to it
-  */
-  LOG_INFO*  current_linfo;
   NET*       slave_net;			// network connection from slave -> m.
 
   /*
@@ -4813,8 +4807,17 @@ private:
 
 public:
 #ifdef HAVE_REPLICATION
+  /*
+    If we do a purge of binary logs, log index info of the threads
+    that are currently reading it needs to be adjusted. To do that
+    each thread that is using LOG_INFO needs to adjust the pointer to it
+  */
+  LOG_INFO *current_linfo;
   Slave_info *slave_info;
 
+  void set_current_linfo(LOG_INFO *linfo);
+  void reset_current_linfo() { set_current_linfo(0); }
+
   int register_slave(uchar *packet, size_t packet_length);
   void unregister_slave();
 #endif
@@ -4975,18 +4978,6 @@ public:
        (THD_TRANS::DID_WAIT | THD_TRANS::CREATED_TEMP_TABLE |
         THD_TRANS::DROPPED_TEMP_TABLE | THD_TRANS::DID_DDL));
   }
-  /*
-    Reset current_linfo
-    Setting current_linfo to 0 needs to be done with LOCK_thd_data to
-    ensure that adjust_linfo_offsets doesn't use a structure that may
-    be deleted.
-  */
-  inline void reset_current_linfo()
-  {
-    mysql_mutex_lock(&LOCK_thd_data);
-    current_linfo= 0;
-    mysql_mutex_unlock(&LOCK_thd_data);
-  }
 
 
   uint get_net_wait_timeout()
diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 7fc3bb5926d..cbcfb2197df 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -506,6 +506,22 @@ static enum enum_binlog_checksum_alg get_binlog_checksum_value_at_connect(THD *
   DBUG_RETURN(ret);
 }
 
+
+/**
+  Set current_linfo
+
+  Setting current_linfo needs to be done with LOCK_thd_data to ensure that
+  adjust_linfo_offsets doesn't use a structure that may be deleted.
+*/
+
+void THD::set_current_linfo(LOG_INFO *linfo)
+{
+  mysql_mutex_lock(&LOCK_thd_data);
+  current_linfo= linfo;
+  mysql_mutex_unlock(&LOCK_thd_data);
+}
+
+
 /*
   Adjust the position pointer in the binary log file for all running slaves
 
@@ -2127,7 +2143,7 @@ static int init_binlog_sender(binlog_send_info *info,
   linfo->pos= *pos;
 
   // note: publish that we use file, before we open it
-  thd->current_linfo= linfo;
+  thd->set_current_linfo(linfo);
 
   if (check_start_offset(info, linfo->log_file_name, *pos))
     return 1;
@@ -3952,7 +3968,7 @@ bool mysql_show_binlog_events(THD* thd)
       goto err;
     }
 
-    thd->current_linfo= &linfo;
+    thd->set_current_linfo(&linfo);
 
     if ((file=open_binlog(&log, linfo.log_file_name, &errmsg)) < 0)
       goto err;