Add more execution stages (commit, rollback, etc)

This was done to get more information about where time is spent.
Now we can get proper timing for time spent in commit, rollback,
binlog write etc.

Following stages was added:
- Commit
- Commit_implicit
- Rollback
- Rollback implicit
- Binlog write
- Init for update
  - This is used instead of "Init" for insert, update and delete.
- Staring cleanup

Following stages where changed:
- "Unlocking tables" stage reset stage to previous stage at end
- "binlog write" stage resets stage to previous stage at end
- "end" -> "end of update loop"
- "cleaning up" -> "Reset for next command"
- Added stage_searching_rows_for_update when searching for rows
  to be deleted.

Other things:
- Renamed all stages to start with big letter (before there was no
  consitency)
- Increased performance_schema_max_stage_classes from 150 to 160.
- Most of the test changes in performance schema comes from renaming of
  stages.
- Removed duplicate output of variables and inital state in a lot of
  performance schema tests.
  This was done to make it easier to change a default value for a
  performance variable without affecting all tests.
- Added start_server_variables.test to check configuration
- Removed some duplicate "closing tables" stages
- Updated position for "stage_init_update" and "stage_updating" for
  delete, insert and update to be just before update loop (for more
  exact timing).
- Don't set "Checking permissions" twice in a row.
- Remove stage_end stage from creating views (not done for create table
  either).
- Updated default performance history size from 10 to 20 because of new
  stages
- Ensure that ps_enabled is correct (to be used in a later patch)

1 files changed, 5 insertions, 1 deletions

diff --git a/sql/lock.cc b/sql/lock.cc
index 83a0896808f..c6dd3724eba 100644
--- a/sql/lock.cc
+++ b/sql/lock.cc
@@ -421,8 +421,11 @@ void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock)
 
 void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock, bool free_lock)
 {
-  DBUG_ENTER("mysql_unlock_tables");
   bool errors= thd->is_error();
+  PSI_stage_info org_stage;
+  DBUG_ENTER("mysql_unlock_tables");
+
+  thd->backup_stage(&org_stage);
   THD_STAGE_INFO(thd, stage_unlocking_tables);
 
   if (sql_lock->table_count)
@@ -433,6 +436,7 @@ void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock, bool free_lock)
     my_free(sql_lock);
   if (!errors)
     thd->clear_error();
+  THD_STAGE_INFO(thd, org_stage);
   DBUG_VOID_RETURN;
 }