Fixed bug in semi_sync replication tests.

The problem was that wait_for_slave_io_to_start reported that the io thread
was ready, when it was still initializing. This caused test suite to
continue too early, for example before the semi sync plugin was properly
enabled.

Fixed by introducing a new internal stage: "Preparing". Slave_IO_Running is
now set to "Yes" only when all initializing is done and the IO thread is
ready to read things from the master.

The only test affected by this change is rpl_flsh_tbls, which got stuck in
the preparing phase while trying to read the GTID position from a table.
Fixed by having this test waiting for Preparing instead of Yes.

4 files changed, 12 insertions, 11 deletions

diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index c6ac3f7a4a2..416193ff1e0 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -7287,8 +7287,8 @@ static int show_slave_running(THD *thd, SHOW_VAR *var, char *buff)
       get_master_info(&thd->variables.default_master_connection,
                       Sql_condition::WARN_LEVEL_NOTE);
     if (mi)
-      tmp= (my_bool) (mi->slave_running == MYSQL_SLAVE_RUN_CONNECT &&
-                      mi->rli.slave_running);
+      tmp= (my_bool) (mi->slave_running == MYSQL_SLAVE_RUN_READING &&
+                      mi->rli.slave_running != MYSQL_SLAVE_NOT_RUN);
   }
   mysql_mutex_unlock(&LOCK_active_mi);
   if (mi)
diff --git a/sql/rpl_mi.cc b/sql/rpl_mi.cc
index a7ee3f3f45e..9c6f4639717 100644
--- a/sql/rpl_mi.cc
+++ b/sql/rpl_mi.cc
@@ -1321,7 +1321,7 @@ bool Master_info_index::start_all_slaves(THD *thd)
       Try to start all slaves that are configured (host is defined)
       and are not already running
     */
-    if ((mi->slave_running != MYSQL_SLAVE_RUN_CONNECT ||
+    if ((mi->slave_running == MYSQL_SLAVE_NOT_RUN ||
          !mi->rli.slave_running) && *mi->host)
     {
       if ((error= start_slave(thd, mi, 1)))
diff --git a/sql/slave.cc b/sql/slave.cc
index 6b2a88a2953..7474aec38ca 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -2615,6 +2615,8 @@ static bool send_show_master_info_header(THD *thd, bool full,
   DBUG_RETURN(FALSE);
 }
 
+/* Text for Slave_IO_Running */
+static const char *slave_running[]= { "No", "Connecting", "Preparing", "Yes" };
 
 static bool send_show_master_info_data(THD *thd, Master_info *mi, bool full,
                                        String *gtid_pos)
@@ -2668,9 +2670,7 @@ static bool send_show_master_info_data(THD *thd, Master_info *mi, bool full,
                     &my_charset_bin);
     protocol->store((ulonglong) mi->rli.group_relay_log_pos);
     protocol->store(mi->rli.group_master_log_name, &my_charset_bin);
-    protocol->store(mi->slave_running == MYSQL_SLAVE_RUN_CONNECT ?
-                    "Yes" : (mi->slave_running == MYSQL_SLAVE_RUN_NOT_CONNECT ?
-                             "Connecting" : "No"), &my_charset_bin);
+    protocol->store(slave_running[mi->slave_running], &my_charset_bin);
     protocol->store(mi->rli.slave_running ? "Yes":"No", &my_charset_bin);
     protocol->store(rpl_filter->get_do_db());
     protocol->store(rpl_filter->get_ignore_db());
@@ -2713,7 +2713,7 @@ static bool send_show_master_info_data(THD *thd, Master_info *mi, bool full,
       Seconds_Behind_Master: if SQL thread is running and I/O thread is
       connected, we can compute it otherwise show NULL (i.e. unknown).
     */
-    if ((mi->slave_running == MYSQL_SLAVE_RUN_CONNECT) &&
+    if ((mi->slave_running == MYSQL_SLAVE_RUN_READING) &&
         mi->rli.slave_running)
     {
       long time_diff;
diff --git a/sql/slave.h b/sql/slave.h
index e16f801b577..5cc02c8a10b 100644
--- a/sql/slave.h
+++ b/sql/slave.h
@@ -132,11 +132,11 @@ extern my_bool opt_replicate_annotate_row_events;
 extern ulonglong relay_log_space_limit;
 
 /*
-  3 possible values for Master_info::slave_running and
+  4 possible values for Master_info::slave_running and
   Relay_log_info::slave_running.
-  The values 0,1,2 are very important: to keep the diff small, I didn't
-  substitute places where we use 0/1 with the newly defined symbols. So don't change
-  these values.
+  The values 0,1,2,3 are very important: to keep the diff small, I didn't
+  substitute places where we use 0/1 with the newly defined symbols.
+  So don't change these values.
   The same way, code is assuming that in Relay_log_info we use only values
   0/1.
   I started with using an enum, but
@@ -145,6 +145,7 @@ extern ulonglong relay_log_space_limit;
 #define MYSQL_SLAVE_NOT_RUN         0
 #define MYSQL_SLAVE_RUN_NOT_CONNECT 1
 #define MYSQL_SLAVE_RUN_CONNECT     2
+#define MYSQL_SLAVE_RUN_READING     3
 
 #define RPL_LOG_NAME (rli->group_master_log_name[0] ? rli->group_master_log_name :\
  "FIRST")