MDEV-7943 - pthread_getspecific() takes 0.76% in OLTP RO

Pass THD to find_all_keys() and Item_equal::Item_equal().
In MRR use table->in_use instead of current_thd.

This reduces number of pthread_getspecific() calls from 354 to 320.

sql/filesort.cc

@@ -50,7 +50,7 @@ if (my_b_write((file),(uchar*) (from),param->ref_length)) \
 
 static uchar *read_buffpek_from_file(IO_CACHE *buffer_file, uint count,
                                      uchar *buf);
-static ha_rows find_all_keys(Sort_param *param,SQL_SELECT *select,
+static ha_rows find_all_keys(THD *thd, Sort_param *param, SQL_SELECT *select,
                              Filesort_info *fs_info,
                              IO_CACHE *buffer_file,
                              IO_CACHE *tempfile,
@@ -294,7 +294,7 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
 
   param.sort_form= table;
   param.end=(param.local_sortorder=sortorder)+s_length;
-  num_rows= find_all_keys(&param, select,
+  num_rows= find_all_keys(thd, &param, select,
                           &table_sort,
                           &buffpek_pointers,
                           &tempfile, 
@@ -667,7 +667,7 @@ static void dbug_print_record(TABLE *table, bool print_rowid)
     HA_POS_ERROR on error.
 */
 
-static ha_rows find_all_keys(Sort_param *param, SQL_SELECT *select,
+static ha_rows find_all_keys(THD *thd, Sort_param *param, SQL_SELECT *select,
                              Filesort_info *fs_info,
 			     IO_CACHE *buffpek_pointers,
                              IO_CACHE *tempfile,
@@ -679,7 +679,6 @@ static ha_rows find_all_keys(Sort_param *param, SQL_SELECT *select,
   uchar *ref_pos,*next_pos,ref_buff[MAX_REFLENGTH];
   my_off_t record;
   TABLE *sort_form;
-  THD *thd= current_thd;
   handler *file;
   MY_BITMAP *save_read_set, *save_write_set, *save_vcol_set;
   

sql/item_cmpfunc.cc

@@ -5628,14 +5628,14 @@ Item *Item_bool_rowready_func2::negated_item()
   of the type Item_field or Item_direct_view_ref(Item_field). 
 */
 
-Item_equal::Item_equal(Item *f1, Item *f2, bool with_const_item)
+Item_equal::Item_equal(THD *thd_arg, Item *f1, Item *f2, bool with_const_item)
   : Item_bool_func(), eval_item(0), cond_false(0), cond_true(0), 
     context_field(NULL), link_equal_fields(FALSE)
 {
   const_item_cache= 0;
   with_const= with_const_item;
-  equal_items.push_back(f1);
-  equal_items.push_back(f2);
+  equal_items.push_back(f1, thd_arg->mem_root);
+  equal_items.push_back(f2, thd_arg->mem_root);
   compare_as_dates= with_const_item && f2->cmp_type() == TIME_RESULT;
   upper_levels= NULL;
   sargable= TRUE; 
@@ -5654,7 +5654,7 @@ Item_equal::Item_equal(Item *f1, Item *f2, bool with_const_item)
   outer join).
 */
 
-Item_equal::Item_equal(Item_equal *item_equal)
+Item_equal::Item_equal(THD *thd_arg, Item_equal *item_equal)
   : Item_bool_func(), eval_item(0), cond_false(0), cond_true(0),
      context_field(NULL), link_equal_fields(FALSE)
 {
@@ -5663,7 +5663,7 @@ Item_equal::Item_equal(Item_equal *item_equal)
   Item *item;
   while ((item= li++))
   {
-    equal_items.push_back(item);
+    equal_items.push_back(item, thd_arg->mem_root);
   }
   with_const= item_equal->with_const;
   compare_as_dates= item_equal->compare_as_dates;

sql/item_cmpfunc.h

@@ -1904,12 +1904,8 @@ class Item_equal: public Item_bool_func
 
   COND_EQUAL *upper_levels;       /* multiple equalities of upper and levels */
 
-  inline Item_equal()
-    : Item_bool_func(), with_const(FALSE), eval_item(0), cond_false(0),
-      context_field(NULL)
-  { const_item_cache=0; sargable= TRUE; }
-  Item_equal(Item *f1, Item *f2, bool with_const_item);
-  Item_equal(Item_equal *item_equal);
+  Item_equal(THD *thd_arg, Item *f1, Item *f2, bool with_const_item);
+  Item_equal(THD *thd_arg, Item_equal *item_equal);
   /* Currently the const item is always the first in the list of equal items */
   inline Item* get_const() { return with_const ? equal_items.head() : NULL; }
   void add_const(THD *thd, Item *c, Item *f = NULL);

sql/multi_range_read.cc

@@ -62,7 +62,7 @@ handler::multi_range_read_info_const(uint keyno, RANGE_SEQ_IF *seq,
   range_seq_t seq_it;
   ha_rows rows, total_rows= 0;
   uint n_ranges=0;
-  THD *thd= current_thd;
+  THD *thd= table->in_use;
   
   /* Default MRR implementation doesn't need buffer */
   *bufsz= 0;
@@ -814,7 +814,7 @@ int DsMrr_impl::dsmrr_init(handler *h_arg, RANGE_SEQ_IF *seq_funcs,
                            void *seq_init_param, uint n_ranges, uint mode,
                            HANDLER_BUFFER *buf)
 {
-  THD *thd= current_thd;
+  THD *thd= h_arg->get_table()->in_use;
   int res;
   Key_parameters keypar;
   uint UNINIT_VAR(key_buff_elem_size); /* set/used when do_sort_keys==TRUE */
@@ -1573,7 +1573,7 @@ bool DsMrr_impl::choose_mrr_impl(uint keyno, ha_rows rows, uint *flags,
 {
   Cost_estimate dsmrr_cost;
   bool res;
-  THD *thd= current_thd;
+  THD *thd= primary_file->get_table()->in_use;
   TABLE_SHARE *share= primary_file->get_table_share();
 
   bool doing_cpk_scan= check_cpk_scan(thd, share, keyno, *flags); 

sql/sql_select.cc

@@ -12502,14 +12502,14 @@ static bool check_simple_equality(THD *thd, Item *left_item, Item *right_item,
     if (left_copyfl)
     {
       /* left_item_equal of an upper level contains left_item */
-      left_item_equal= new (thd->mem_root) Item_equal(left_item_equal);
+      left_item_equal= new (thd->mem_root) Item_equal(thd, left_item_equal);
       left_item_equal->set_context_field(((Item_field*) left_item));
       cond_equal->current_level.push_back(left_item_equal);
     }
     if (right_copyfl)
     {
       /* right_item_equal of an upper level contains right_item */
-      right_item_equal= new (thd->mem_root) Item_equal(right_item_equal);
+      right_item_equal= new (thd->mem_root) Item_equal(thd, right_item_equal);
       right_item_equal->set_context_field(((Item_field*) right_item));
       cond_equal->current_level.push_back(right_item_equal);
     }
@@ -12537,7 +12537,8 @@ static bool check_simple_equality(THD *thd, Item *left_item, Item *right_item,
       else 
       {
         /* None of the fields was found in multiple equalities */
-        Item_equal *item_equal= new (thd->mem_root) Item_equal(orig_left_item,
+        Item_equal *item_equal= new (thd->mem_root) Item_equal(thd,
+                                                               orig_left_item,
                                                                orig_right_item,
                                                                FALSE);
         item_equal->set_context_field((Item_field*)left_item);
@@ -12596,7 +12597,7 @@ static bool check_simple_equality(THD *thd, Item *left_item, Item *right_item,
                                                field_item->field, &copyfl);
       if (copyfl)
       {
-        item_equal= new (thd->mem_root) Item_equal(item_equal);
+        item_equal= new (thd->mem_root) Item_equal(thd, item_equal);
         cond_equal->current_level.push_back(item_equal);
         item_equal->set_context_field(field_item);
       }
@@ -12611,8 +12612,8 @@ static bool check_simple_equality(THD *thd, Item *left_item, Item *right_item,
       }
       else
       {
-        item_equal= new (thd->mem_root) Item_equal(const_item, orig_field_item,
-                                                   TRUE);
+        item_equal= new (thd->mem_root) Item_equal(thd, const_item,
+                                                   orig_field_item, TRUE);
         item_equal->set_context_field(field_item);
         cond_equal->current_level.push_back(item_equal, thd->mem_root);
       }