MDEV-7437 remove suport for "atomics" with rwlocks

1 files changed, 2 insertions, 20 deletions

diff --git a/sql/table_cache.cc b/sql/table_cache.cc
index f12c031f91a..9a75cafb30e 100644
--- a/sql/table_cache.cc
+++ b/sql/table_cache.cc
@@ -82,7 +82,6 @@ static int32 tc_count; /**< Number of TABLE objects in table cache. */
 */
 
 static mysql_mutex_t LOCK_unused_shares;
-my_atomic_rwlock_t LOCK_tdc_atomics; /**< Protects tdc_version. */
 
 #ifdef HAVE_PSI_INTERFACE
 PSI_mutex_key key_LOCK_unused_shares, key_TABLE_SHARE_LOCK_table_share;
@@ -136,11 +135,7 @@ static int fix_thd_pins(THD *thd)
 
 uint tc_records(void)
 {
-  uint count;
-  my_atomic_rwlock_rdlock(&LOCK_tdc_atomics);
-  count= my_atomic_load32_explicit(&tc_count, MY_MEMORY_ORDER_RELAXED);
-  my_atomic_rwlock_rdunlock(&LOCK_tdc_atomics);
-  return count;
+  return my_atomic_load32_explicit(&tc_count, MY_MEMORY_ORDER_RELAXED);
 }
 
 
@@ -153,9 +148,7 @@ uint tc_records(void)
 
 static void tc_remove_table(TABLE *table)
 {
-  my_atomic_rwlock_wrlock(&LOCK_tdc_atomics);
   my_atomic_add32_explicit(&tc_count, -1, MY_MEMORY_ORDER_RELAXED);
-  my_atomic_rwlock_wrunlock(&LOCK_tdc_atomics);
   table->s->tdc->all_tables.remove(table);
 }
 
@@ -262,10 +255,8 @@ void tc_add_table(THD *thd, TABLE *table)
   mysql_mutex_unlock(&table->s->tdc->LOCK_table_share);
 
   /* If we have too many TABLE instances around, try to get rid of them */
-  my_atomic_rwlock_wrlock(&LOCK_tdc_atomics);
   need_purge= my_atomic_add32_explicit(&tc_count, 1, MY_MEMORY_ORDER_RELAXED) >=
               (int32) tc_size;
-  my_atomic_rwlock_wrunlock(&LOCK_tdc_atomics);
 
   if (need_purge)
   {
@@ -435,7 +426,6 @@ void tdc_init(void)
   tdc_inited= true;
   mysql_mutex_init(key_LOCK_unused_shares, &LOCK_unused_shares,
                    MY_MUTEX_INIT_FAST);
-  my_atomic_rwlock_init(&LOCK_tdc_atomics);
   tdc_version= 1L;  /* Increments on each reload */
   lf_hash_init(&tdc_hash, sizeof(TDC_element), LF_HASH_UNIQUE, 0, 0,
                (my_hash_get_key) TDC_element::key,
@@ -484,7 +474,6 @@ void tdc_deinit(void)
   {
     tdc_inited= false;
     lf_hash_destroy(&tdc_hash);
-    my_atomic_rwlock_destroy(&LOCK_tdc_atomics);
     mysql_mutex_destroy(&LOCK_unused_shares);
   }
   DBUG_VOID_RETURN;
@@ -1000,18 +989,13 @@ int tdc_wait_for_old_version(THD *thd, const char *db, const char *table_name,
 
 ulong tdc_refresh_version(void)
 {
-  my_atomic_rwlock_rdlock(&LOCK_tdc_atomics);
-  ulong v= my_atomic_load64_explicit(&tdc_version, MY_MEMORY_ORDER_RELAXED);
-  my_atomic_rwlock_rdunlock(&LOCK_tdc_atomics);
-  return v;
+  return my_atomic_load64_explicit(&tdc_version, MY_MEMORY_ORDER_RELAXED);
 }
 
 
 ulong tdc_increment_refresh_version(void)
 {
-  my_atomic_rwlock_wrlock(&LOCK_tdc_atomics);
   ulong v= my_atomic_add64_explicit(&tdc_version, 1, MY_MEMORY_ORDER_RELAXED);
-  my_atomic_rwlock_wrunlock(&LOCK_tdc_atomics);
   DBUG_PRINT("tcache", ("incremented global refresh_version to: %lu", v));
   return v + 1;
 }
@@ -1154,9 +1138,7 @@ void tdc_assign_new_table_id(TABLE_SHARE *share)
   */
   do
   {
-    my_atomic_rwlock_wrlock(&LOCK_tdc_atomics);
     tid= my_atomic_add64_explicit(&last_table_id, 1, MY_MEMORY_ORDER_RELAXED);
-    my_atomic_rwlock_wrunlock(&LOCK_tdc_atomics);
   } while (unlikely(tid == ~0UL));
 
   share->table_map_id= tid;