Backport of:

------------------------------------------------------------
revno: 2617.68.24
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 17:25:29 +0400
message:
  Pre-requisite patch for fixing bug #30977 "Concurrent statement
  using stored function and DROP FUNCTION breaks SBR".

  Added MDL_request for stored routine as member to Sroutine_hash_entry
  in order to be able perform metadata locking for stored routines in
  future (Sroutine_hash_entry is an equivalent of TABLE_LIST class for
  stored routines).
(WL#4284, follow up fixes).

sql/mdl.cc:
  Introduced version of MDL_request::init() method which initializes
  lock request using pre-built MDL key.
  MDL_key::table_name/table_name_length() getters were
  renamed to reflect the fact that MDL_key objects are
  now created not only for tables.
sql/mdl.h:
  Extended enum_mdl_namespace enum with values which correspond
  to namespaces for stored functions and triggers.
  Renamed MDL_key::table_name/table_name_length() getters
  to MDL_key::name() and name_length() correspondingly to
  reflect the fact that MDL_key objects are now created
  not only for tables.
  Added MDL_key::mdl_namespace() getter.
  Also added version of MDL_request::init() method which
  initializes lock request using pre-built MDL key.
sql/sp.cc:
  Added MDL_request for stored routine as member to Sroutine_hash_entry.
  Changed code to use MDL_key from this request as a key for LEX::sroutines
  set. Removed separate "key" member from Sroutine_hash_entry as it became
  unnecessary.
sql/sp.h:
  Added MDL_request for stored routine as member to Sroutine_hash_entry
  in order to be able perform metadata locking for stored routines in
  future (Sroutine_hash_entry is an equivalent of TABLE_LIST class for
  stored routines).
  Removed Sroutine_hash_entry::key member as now we can use MDL_key from
  this request as a key for LEX::sroutines set.
sql/sp_head.cc:
  Removed sp_name::m_sroutines_key member and set_routine_type() method.
  Since key for routine in LEX::sroutines set has no longer sp_name::m_qname
  as suffix we won't save anything by creating it at sp_name construction
  time.
  Adjusted sp_name constructor used for creating temporary objects for
  lookups in SP-cache to accept MDL_key as parameter and to avoid any
  memory allocation.
  Finally, removed sp_head::m_soutines_key member for reasons similar
  to why sp_name::m_sroutines_key was removed
sql/sp_head.h:
  Removed sp_name::m_sroutines_key member and set_routine_type() method.
  Since key for routine in LEX::sroutines set has no longer sp_name::m_qname
  as suffix we won't save anything by creating it at sp_name construction
  time.
  Adjusted sp_name constructor used for creating temporary objects for
  lookups in SP-cache to accept MDL_key as parameter and to avoid any
  memory allocation.
  Finally, removed sp_head::m_soutines_key member for reasons similar
  to why sp_name::m_sroutines_key was removed.
sql/sql_base.cc:
  Adjusted code to the fact that we now use MDL_key from
  Sroutine_hash_entry::mdl_request as a key for LEX::sroutines set.
  MDL_key::table_name/table_name_length() getters were
  renamed to reflect the fact that MDL_key objects are
  now created not only for tables.
sql/sql_trigger.cc:
  sp_add_used_routine() now takes MDL_key as parameter as now we use
  instance of this class as a key for LEX::sroutines set.

1 files changed, 20 insertions, 2 deletions

diff --git a/sql/mdl.cc b/sql/mdl.cc
index 879b12a4cac..5bda56193f5 100644
--- a/sql/mdl.cc
+++ b/sql/mdl.cc
@@ -319,6 +319,24 @@ void MDL_request::init(enum_mdl_namespace mdl_namespace,
 
 
 /**
+  Initialize a lock request using pre-built MDL_key.
+
+  @sa MDL_request::init(namespace, db, name, type).
+
+  @param key_arg       The pre-built MDL key for the request.
+  @param mdl_type_arg  The MDL lock type for the request.
+*/
+
+void MDL_request::init(const MDL_key *key_arg,
+                       enum enum_mdl_type mdl_type_arg)
+{
+  key.mdl_key_init(key_arg);
+  type= mdl_type_arg;
+  ticket= NULL;
+}
+
+
+/**
   Allocate and initialize one lock request.
 
   Same as mdl_init_lock(), but allocates the lock and the key buffer
@@ -1254,7 +1272,7 @@ void MDL_context::release_ticket(MDL_ticket *ticket)
   MDL_lock *lock= ticket->m_lock;
   DBUG_ENTER("release_ticket");
   DBUG_PRINT("enter", ("db=%s name=%s", lock->key.db_name(),
-                                        lock->key.table_name()));
+                                        lock->key.name()));
 
   safe_mutex_assert_owner(&LOCK_mdl);
 
@@ -1526,7 +1544,7 @@ MDL_ticket::set_cached_object(void *cached_object,
 {
   DBUG_ENTER("mdl_set_cached_object");
   DBUG_PRINT("enter", ("db=%s name=%s cached_object=%p",
-                        m_lock->key.db_name(), m_lock->key.table_name(),
+                        m_lock->key.db_name(), m_lock->key.name(),
                         cached_object));
   /*
     TODO: This assumption works now since we do get_cached_object()