Fix 'n' concurrent prepared executions

libmysql/errmsg.c

@@ -59,7 +59,7 @@ const char *client_errors[]=
   "No parameters exists in the statement",
   "Invalid parameter number",
   "Can't send long data for non string or binary data types (parameter: %d)",
-  "Using un supported parameter type: %d  (parameter: %d)"
+  "Using un supported buffer type: %d  (parameter: %d)",
   "Shared memory (%lu)",
   "Can't open shared memory. Request event don't create  (%lu)",
   "Can't open shared memory. Answer event don't create  (%lu)",
@@ -114,7 +114,7 @@ const char *client_errors[]=
   "No parameters exists in the statement",
   "Invalid parameter number",
   "Can't send long data for non string or binary data types (parameter: %d)",
-  "Using un supported parameter type: %d  (parameter: %d)"
+  "Using un supported buffer type: %d  (parameter: %d)",
   "Shared memory (%lu)",
   "Can't open shared memory. Request event don't create  (%lu)",
   "Can't open shared memory. Answer event don't create  (%lu)",
@@ -167,7 +167,7 @@ const char *client_errors[]=
   "No parameters exists in the statement",
   "Invalid parameter number",
   "Can't send long data for non string or binary data types (parameter: %d)",
-  "Using un supported parameter type: %d  (parameter: %d)"
+  "Using un supported buffer type: %d  (parameter: %d)",
   "Shared memory (%lu)",
   "Can't open shared memory. Request event don't create  (%lu)",
   "Can't open shared memory. Answer event don't create  (%lu)",

libmysql/libmysql.c

@@ -3925,6 +3925,28 @@ mysql_prepare(MYSQL  *mysql, const char *query, ulong length)
   DBUG_RETURN(stmt);
 }
 
+/*
+  Get the execute query meta information for non-select 
+  statements (on demand).
+*/
+
+unsigned int alloc_stmt_fields(MYSQL_STMT *stmt)
+{
+  MYSQL_FIELD *fields;
+  
+  if (!stmt->mysql->field_count)
+    return 0;
+  stmt->field_count= stmt->mysql->field_count;
+  fields= stmt->mysql->fields;
+  
+  if (!(stmt->fields= (MYSQL_FIELD *) alloc_root(&stmt->mem_root, 
+        sizeof(fields))) || 
+      !(stmt->bind= (MYSQL_BIND *) alloc_root(&stmt->mem_root, 
+        sizeof(MYSQL_BIND ) * stmt->field_count)))
+    return 0;
+  memcpy((char *)stmt->fields, (char *)fields, sizeof(fields));
+  return stmt->field_count;
+}
 
 /*
   Returns prepared meta information in the form of resultset
@@ -3938,8 +3960,10 @@ mysql_prepare_result(MYSQL_STMT *stmt)
   DBUG_ENTER("mysql_prepare_result");
   
   if (!stmt->field_count || !stmt->fields)
-    DBUG_RETURN(0);
-  
+  {
+    if (!alloc_stmt_fields(stmt))
+      DBUG_RETURN(0);
+  }  
   if (!(result=(MYSQL_RES*) my_malloc(sizeof(*result)+
 				      sizeof(ulong)*stmt->field_count,
 				      MYF(MY_WME | MY_ZEROFILL))))
@@ -4436,7 +4460,7 @@ my_bool STDCALL mysql_bind_param(MYSQL_STMT *stmt, MYSQL_BIND * bind)
     default:
       sprintf(stmt->last_error,
 	      ER(stmt->last_errno= CR_UNSUPPORTED_PARAM_TYPE),
-	      param->buffer_type, param->param_number);
+	      param->buffer_type, count);
       DBUG_RETURN(1);
     }
   }
@@ -4984,6 +5008,7 @@ my_bool STDCALL mysql_bind_result(MYSQL_STMT *stmt, MYSQL_BIND *bind)
 {
   MYSQL_BIND *param, *end;
   ulong       bind_count;
+  uint        param_count= 0;
   DBUG_ENTER("mysql_bind_result");
   DBUG_ASSERT(stmt != 0);
 
@@ -4999,7 +5024,10 @@ my_bool STDCALL mysql_bind_result(MYSQL_STMT *stmt, MYSQL_BIND *bind)
     DBUG_RETURN(1);
   }
 #endif
-  bind_count= stmt->field_count;
+  if (!(bind_count= stmt->field_count) && 
+      !(bind_count= alloc_stmt_fields(stmt)))
+    DBUG_RETURN(0);
+  
   memcpy((char*) stmt->bind, (char*) bind,
 	 sizeof(MYSQL_BIND)*bind_count);
 
@@ -5015,6 +5043,7 @@ my_bool STDCALL mysql_bind_result(MYSQL_STMT *stmt, MYSQL_BIND *bind)
     if (!param->length)
       param->length= &param->buffer_length;
 
+    param->param_number= param_count++;
     /* Setup data copy functions for the different supported types */
     switch (param->buffer_type) {
     case MYSQL_TYPE_TINY:
@@ -5066,7 +5095,7 @@ my_bool STDCALL mysql_bind_result(MYSQL_STMT *stmt, MYSQL_BIND *bind)
     default:
       sprintf(stmt->last_error,
 	      ER(stmt->last_errno= CR_UNSUPPORTED_PARAM_TYPE),
-	      param->buffer_type, param->param_number);
+	      param->buffer_type, param_count);
       DBUG_RETURN(1);
     }
   }
@@ -5303,6 +5332,7 @@ static my_bool stmt_close(MYSQL_STMT *stmt, my_bool skip_list)
   free_root(&stmt->mem_root, MYF(0));
   if (!skip_list)
     stmt->mysql->stmts= list_delete(stmt->mysql->stmts, &stmt->list);
+  stmt->mysql->status= MYSQL_STATUS_READY;
   my_free((gptr) stmt, MYF(MY_WME));
   DBUG_RETURN(error);
 }

sql/sql_class.h

@@ -327,6 +327,7 @@ public:
 typedef struct st_prep_stmt
 {
   THD *thd;
+  LEX  lex; 
   Item_param **param;
   Item *free_list;
   MEM_ROOT mem_root;

sql/sql_prepare.cc

@@ -684,6 +684,7 @@ static bool init_param_items(PREP_STMT *stmt)
   List<Item> &params= stmt->thd->lex.param_list;
   Item_param **to;
  
+  stmt->lex=  stmt->thd->lex;
   if (!stmt->param_count)
     stmt->param= (Item_param **)0;
   else
@@ -705,7 +706,7 @@ static bool init_param_items(PREP_STMT *stmt)
 static void init_stmt_execute(PREP_STMT *stmt)
 {
   THD *thd= stmt->thd;
-  TABLE_LIST *tables=(TABLE_LIST*) thd->lex.select_lex.table_list.first;
+  TABLE_LIST *tables= (TABLE_LIST*) thd->lex.select_lex.table_list.first;
   
   /*
   TODO: When the new table structure is ready, then have a status bit 
@@ -713,7 +714,7 @@ static void init_stmt_execute(PREP_STMT *stmt)
         and open the tables back.
   */
   if (tables)
-    tables->table=0; //safety - nasty init
+    tables->table= 0; //safety - nasty init
 }
 
 /*
@@ -796,10 +797,8 @@ void mysql_stmt_execute(THD *thd, char *packet)
     DBUG_VOID_RETURN;
   }
 
-  if (my_pthread_setspecific_ptr(THR_THD, stmt->thd) ||
-      my_pthread_setspecific_ptr(THR_MALLOC, &stmt->thd->mem_root))
-    DBUG_VOID_RETURN;
-
+  LEX thd_lex= thd->lex;
+  thd->lex= stmt->lex;
   init_stmt_execute(stmt);
 
   if (stmt->param_count && setup_params_data(stmt))
@@ -814,17 +813,14 @@ void mysql_stmt_execute(THD *thd, char *packet)
     mysql_delete(), mysql_update() and mysql_select() to not to 
     have re-check on setup_* and other things ..
   */  
-  THD *cur_thd= stmt->thd;
-  cur_thd->protocol= &cur_thd->protocol_prep;		// Switch to binary protocol
-  mysql_execute_command(cur_thd);
-  cur_thd->protocol= &cur_thd->protocol_simple;	// Use normal protocol
+  thd->protocol= &thd->protocol_prep;		// Switch to binary protocol
+  mysql_execute_command(thd);
+  thd->protocol= &thd->protocol_simple;	// Use normal protocol
 
   if (!(specialflag & SPECIAL_NO_PRIOR))
     my_pthread_setprio(pthread_self(), WAIT_PRIOR);
 
-  my_pthread_setspecific_ptr(THR_THD, thd);
-  my_pthread_setspecific_ptr(THR_MALLOC, &thd->mem_root);
-
+  thd->lex= thd_lex;
   DBUG_VOID_RETURN;
 }