MDEV-4702 - Reduce usage of LOCK_open

Following variables do not require LOCK_open protection anymore:
- table_def_cache (renamed to tdc_hash) is protected by rw-lock
  LOCK_tdc_hash;
- table_def_shutdown_in_progress doesn't need LOCK_open protection;
- last_table_id use atomics;
- TABLE_SHARE::ref_count (renamed to TABLE_SHARE::tdc.ref_count)
  is protected by TABLE_SHARE::tdc.LOCK_table_share;
- TABLE_SHARE::next, ::prev (renamed to tdc.next and tdc.prev),
  oldest_unused_share, end_of_unused_share are protected by
  LOCK_unused_shares;
- TABLE_SHARE::m_flush_tickets (renamed to tdc.m_flush_tickets)
  is protected by TABLE_SHARE::tdc.LOCK_table_share;
- refresh_version (renamed to tdc_version) use atomics.

1 files changed, 14 insertions, 16 deletions

diff --git a/sql/sql_test.cc b/sql/sql_test.cc
index 867d49808e1..1a241521fd7 100644
--- a/sql/sql_test.cc
+++ b/sql/sql_test.cc
@@ -20,7 +20,7 @@
 #include "sql_priv.h"
 #include "unireg.h"
 #include "sql_test.h"
-#include "sql_base.h" // table_def_cache, table_cache_count, unused_tables
+#include "sql_base.h" // unused_tables
 #include "sql_show.h" // calc_sum_of_all_status
 #include "sql_select.h"
 #include "keycaches.h"
@@ -78,21 +78,21 @@ print_where(COND *cond,const char *info, enum_query_type query_type)
 
 static void print_cached_tables(void)
 {
-  uint idx,count,unused;
+  uint count= 0, unused= 0;
   TABLE_SHARE *share;
   TABLE *start_link, *lnk, *entry;
+  TDC_iterator tdc_it;
 
   compile_time_assert(TL_WRITE_ONLY+1 == array_elements(lock_descriptions));
 
   /* purecov: begin tested */
-  mysql_mutex_lock(&LOCK_open);
   puts("DB             Table                            Version  Thread  Open  Lock");
 
-  for (idx=unused=0 ; idx < table_def_cache.records ; idx++)
+  tdc_it.init();
+  mysql_mutex_lock(&LOCK_open);
+  while ((share= tdc_it.next()))
   {
-    share= (TABLE_SHARE*) my_hash_element(&table_def_cache, idx);
-
-    TABLE_SHARE::TABLE_list::Iterator it(share->used_tables);
+    TABLE_SHARE::TABLE_list::Iterator it(share->tdc.used_tables);
     while ((entry= it++))
     {
       printf("%-14.14s %-32s%6ld%8ld%6d  %s\n",
@@ -100,7 +100,7 @@ static void print_cached_tables(void)
              entry->in_use->thread_id, entry->db_stat ? 1 : 0,
              lock_descriptions[(int)entry->reginfo.lock_type]);
     }
-    it.init(share->free_tables);
+    it.init(share->tdc.free_tables);
     while ((entry= it++))
     {
       unused++;
@@ -109,7 +109,7 @@ static void print_cached_tables(void)
              0L, entry->db_stat ? 1 : 0, "Not in use");
     }
   }
-  count=0;
+  tdc_it.deinit();
   if ((start_link=lnk=unused_tables))
   {
     do
@@ -119,20 +119,18 @@ static void print_cached_tables(void)
 	printf("unused_links isn't linked properly\n");
 	return;
       }
-    } while (count++ < cached_open_tables() && (lnk=lnk->next) != start_link);
+    } while (count++ < tc_records() && (lnk=lnk->next) != start_link);
     if (lnk != start_link)
     {
       printf("Unused_links aren't connected\n");
     }
   }
+  mysql_mutex_unlock(&LOCK_open);
   if (count != unused)
     printf("Unused_links (%d) doesn't match table_def_cache: %d\n", count,
            unused);
-  printf("\nCurrent refresh version: %ld\n",refresh_version);
-  if (my_hash_check(&table_def_cache))
-    printf("Error: Table definition hash table is corrupted\n");
+  printf("\nCurrent refresh version: %ld\n", tdc_refresh_version());
   fflush(stdout);
-  mysql_mutex_unlock(&LOCK_open);
   /* purecov: end */
   return;
 }
@@ -485,7 +483,7 @@ static void display_table_locks(void)
   DYNAMIC_ARRAY saved_table_locks;
 
   (void) my_init_dynamic_array(&saved_table_locks,sizeof(TABLE_LOCK_INFO),
-                               cached_open_tables() + 20, 50,
+                               tc_records() + 20, 50,
                                MYF(MY_THREAD_SPECIFIC));
   mysql_mutex_lock(&THR_LOCK_lock);
   for (list= thr_lock_thread_list; list; list= list_rest(list))
@@ -616,7 +614,7 @@ Open tables:   %10lu\n\
 Open files:    %10lu\n\
 Open streams:  %10lu\n",
 	 tmp.opened_tables,
-	 (ulong) cached_open_tables(),
+	 (ulong) tc_records(),
 	 (ulong) my_file_opened,
 	 (ulong) my_stream_opened);