Better approach for prelocking of tables for stored routines execution

and some SP-related cleanups.

- We don't have separate stage for calculation of list of tables
  to be prelocked and doing implicit LOCK/UNLOCK any more.
  Instead we calculate this list at open_tables() and do implicit
  LOCK in lock_tables() (and UNLOCK in close_thread_tables()).
  Also now we support cases when same table (with same alias) is
  used several times in the same query in SP.

- Cleaned up execution of SP. Moved all common code which handles
  LEX and does preparations before statement execution or complex
  expression evaluation to auxilary sp_lex_keeper class. Now 
  all statements in SP (and corresponding instructions) that
  evaluate expression which can contain subquery have their
  own LEX.

1 files changed, 4 insertions, 4 deletions

diff --git a/sql/sp.h b/sql/sp.h
index 6290324bb86..00dd8416c1d 100644
--- a/sql/sp.h
+++ b/sql/sp.h
@@ -34,7 +34,7 @@ int
 sp_drop_db_routines(THD *thd, char *db);
 
 sp_head *
-sp_find_procedure(THD *thd, sp_name *name);
+sp_find_procedure(THD *thd, sp_name *name, bool cache_only = 0);
 
 int
 sp_exists_routine(THD *thd, TABLE_LIST *procs, bool any, bool no_error);
@@ -82,10 +82,10 @@ sp_function_exists(THD *thd, sp_name *name);
  */
 void
 sp_add_to_hash(HASH *h, sp_name *fun);
-void
+bool
 sp_merge_hash(HASH *dst, HASH *src);
-int
-sp_cache_routines(THD *thd, LEX *lex, int type);
+void
+sp_cache_routines(THD *thd, LEX *lex);
 
 
 //