Fix for BUG#12228: SP cache code:

* Cleanup SP Cache code, now SP Cache only deletes sp_head objects in 
  sp_cache_flush_obsolete() invalidates all pointers to routines in the cache.
* Use new SP Cache use contract in the code.

There is no test case because it doesn't seem to be possible to cause thread races to end
the same way they end in heavy-load test. This patch removes the crash in heavy test.

1 files changed, 4 insertions, 12 deletions

diff --git a/sql/sp.cc b/sql/sp.cc
index 297e17de689..e875c30ab1b 100644
--- a/sql/sp.cc
+++ b/sql/sp.cc
@@ -986,13 +986,11 @@ int
 sp_drop_procedure(THD *thd, sp_name *name)
 {
   int ret;
-  bool found;
   DBUG_ENTER("sp_drop_procedure");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  found= sp_cache_remove(&thd->sp_proc_cache, name);
   ret= db_drop_routine(thd, TYPE_ENUM_PROCEDURE, name);
-  if (!found && !ret)
+  if (!ret)
     sp_cache_invalidate();
   DBUG_RETURN(ret);
 }
@@ -1002,13 +1000,11 @@ int
 sp_update_procedure(THD *thd, sp_name *name, st_sp_chistics *chistics)
 {
   int ret;
-  bool found;
   DBUG_ENTER("sp_update_procedure");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  found= sp_cache_remove(&thd->sp_proc_cache, name);
   ret= db_update_routine(thd, TYPE_ENUM_PROCEDURE, name, chistics);
-  if (!found && !ret)
+  if (!ret)
     sp_cache_invalidate();
   DBUG_RETURN(ret);
 }
@@ -1099,13 +1095,11 @@ int
 sp_drop_function(THD *thd, sp_name *name)
 {
   int ret;
-  bool found;
   DBUG_ENTER("sp_drop_function");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  found= sp_cache_remove(&thd->sp_func_cache, name);
   ret= db_drop_routine(thd, TYPE_ENUM_FUNCTION, name);
-  if (!found && !ret)
+  if (!ret)
     sp_cache_invalidate();
   DBUG_RETURN(ret);
 }
@@ -1115,13 +1109,11 @@ int
 sp_update_function(THD *thd, sp_name *name, st_sp_chistics *chistics)
 {
   int ret;
-  bool found;
   DBUG_ENTER("sp_update_procedure");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  found= sp_cache_remove(&thd->sp_func_cache, name);
   ret= db_update_routine(thd, TYPE_ENUM_FUNCTION, name, chistics);
-  if (!found && !ret)
+  if (!ret)
     sp_cache_invalidate();
   DBUG_RETURN(ret);
 }