MDEV-4506: Parallel replication: Intermediate commit

Remove Relay_log_info::group_info. (It is not thread safe).

sql/rpl_parallel.cc

@@ -68,8 +68,6 @@ rpt_handle_event(rpl_parallel_thread::queued_event *qev,
 
   thd->rgi_slave= rgi;
   thd->rpl_filter = rli->mi->rpl_filter;
-  /* ToDo: Get rid of rli->group_info, it is not thread safe. */
-  rli->group_info= rgi;
 
   /* ToDo: Access to thd, and what about rli, split out a parallel part? */
   mysql_mutex_lock(&rli->data_lock);
@@ -203,7 +201,7 @@ handle_rpl_parallel_thread(void *arg)
            !strcmp("ROLLBACK", ((Query_log_event *)events->ev)->query))));
 
       /* ToDo: must use rgi here, not rli, for thread safety. */
-      delete_or_keep_event_post_apply(rgi->rli, event_type, events->ev);
+      delete_or_keep_event_post_apply(rgi, event_type, events->ev);
       my_free(events);
 
       if (end_of_group)
@@ -661,7 +659,7 @@ rpl_parallel::do_event(struct rpl_group_info *serial_rgi, Log_event *ev)
     */
     qev->rgi= serial_rgi;
     rpt_handle_event(qev, NULL);
-    delete_or_keep_event_post_apply(rli, typ, qev->ev);
+    delete_or_keep_event_post_apply(serial_rgi, typ, qev->ev);
 
     return false;
   }

sql/rpl_rli.cc

@@ -59,7 +59,7 @@ Relay_log_info::Relay_log_info(bool is_slave_recovery)
    abort_pos_wait(0), slave_run_id(0), sql_thd(0),
    inited(0), abort_slave(0), slave_running(0), until_condition(UNTIL_NONE),
    until_log_pos(0), retried_trans(0), executed_entries(0),
-   group_info(0), tables_to_lock(0), tables_to_lock_count(0),
+   tables_to_lock(0), tables_to_lock_count(0),
    last_event_start_time(0), m_flags(0),
    row_stmt_start_timestamp(0), long_find_row_note_printed(false),
    m_annotate_event(0)
@@ -1559,7 +1559,7 @@ event_group_new_gtid(rpl_group_info *rgi, Gtid_log_event *gev)
 
 
 void
-delete_or_keep_event_post_apply(Relay_log_info *rli,
+delete_or_keep_event_post_apply(rpl_group_info *rgi,
                                 Log_event_type typ, Log_event *ev)
 {
   /*
@@ -1583,7 +1583,7 @@ delete_or_keep_event_post_apply(Relay_log_info *rli,
       The thd->query will be used to generate new Annotate_rows event
       during applying the subsequent Rows events.
     */
-    rli->set_annotate_event((Annotate_rows_log_event*) ev);
+    rgi->rli->set_annotate_event((Annotate_rows_log_event*) ev);
     break;
   case DELETE_ROWS_EVENT:
   case UPDATE_ROWS_EVENT:
@@ -1593,11 +1593,11 @@ delete_or_keep_event_post_apply(Relay_log_info *rli,
       event (if any) is not needed anymore and can be deleted.
     */
     if (((Rows_log_event*)ev)->get_flags(Rows_log_event::STMT_END_F))
-      rli->free_annotate_event();
+      rgi->rli->free_annotate_event();
     /* fall through */
   default:
     DBUG_PRINT("info", ("Deleting the event after it has been executed"));
-    if (!rli->group_info->is_deferred_event(ev))
+    if (!rgi->is_deferred_event(ev))
       delete ev;
     break;
   }

sql/rpl_rli.h

@@ -314,8 +314,6 @@ class Relay_log_info : public Slave_reporting_capability
   char slave_patternload_file[FN_REFLEN]; 
   size_t slave_patternload_file_size;  
 
-  /* ToDo: We need to remove this, always use the per-transaction one to work with parallel replication. */
-  struct rpl_group_info *group_info;
   rpl_parallel parallel;
 
   Relay_log_info(bool is_slave_recovery);
@@ -657,7 +655,7 @@ extern struct rpl_slave_state rpl_global_gtid_slave_state;
 
 int rpl_load_gtid_slave_state(THD *thd);
 int event_group_new_gtid(rpl_group_info *rgi, Gtid_log_event *gev);
-void delete_or_keep_event_post_apply(Relay_log_info *rli,
+void delete_or_keep_event_post_apply(rpl_group_info *rgi,
                                      Log_event_type typ, Log_event *ev);
 
 #endif /* RPL_RLI_H */

sql/slave.cc

@@ -3264,7 +3264,7 @@ static int exec_relay_log_event(THD* thd, Relay_log_info* rli,
 
     exec_res= apply_event_and_update_pos(ev, thd, serial_rgi, NULL);
 
-    delete_or_keep_event_post_apply(rli, typ, ev);
+    delete_or_keep_event_post_apply(serial_rgi, typ, ev);
 
     /*
       update_log_pos failed: this should not happen, so we don't
@@ -4189,13 +4189,6 @@ log '%s' at position %s, relay log '%s' position: %s%s", RPL_LOG_NAME,
   }
   mysql_mutex_unlock(&rli->data_lock);
 
-  /*
-    ToDo: Get rid of this, all accesses to rpl_group_info must be made
-    per-worker-thread to work with parallel replication.
-  */
-  if (opt_slave_parallel_threads <= 0)
-    rli->group_info= &serial_rgi;
-
   /* Read queries from the IO/THREAD until this thread is killed */
 
   while (!sql_slave_killed(thd,rli))