MDEV-19529 InnoDB hang on DROP FULLTEXT INDEX

Problem:
=======
  During dropping of fts index, InnoDB waits for fts_optimize_remove_table()
and it holds dict_sys->mutex and dict_operaiton_lock even though the
table id is not present in the queue. But fts_optimize_thread does wait
for dict_sys->mutex to process the unrelated table id from the slot.

Solution:
========
  Whenever table is added to fts_optimize_wq, update the fts_status
of in-memory fts subsystem to TABLE_IN_QUEUE. Whenever drop index
wants to remove table from the queue, it can check the fts_status
to decide whether it should send the MSG_DELETE_TABLE to the queue.

Removed the following functions because these are all deadcode.
dict_table_wait_for_bg_threads_to_exit(),
fts_wait_for_background_thread_to_start(),fts_start_shutdown(), fts_shudown().

1 files changed, 1 insertions, 2 deletions

diff --git a/storage/innobase/fts/fts0config.cc b/storage/innobase/fts/fts0config.cc
index 940c944a436..b39d568575c 100644
--- a/storage/innobase/fts/fts0config.cc
+++ b/storage/innobase/fts/fts0config.cc
@@ -224,8 +224,7 @@ fts_config_set_value(
 	pars_info_bind_varchar_literal(info, "value",
 				       value->f_str, value->f_len);
 
-	const bool dict_locked = fts_table->table->fts->fts_status
-		& TABLE_DICT_LOCKED;
+	const bool dict_locked = fts_table->table->fts->dict_locked;
 
 	fts_table->suffix = "CONFIG";
 	fts_get_table_name(fts_table, table_name, dict_locked);