BUG#26362562 COMMIT_ORDER_MANAGER INSTRUMENTATION IS INCOMPLETE

Description
===========
mysql_mutex_destroy was not called in ~Commit_order_manager. It
caused a memory leak in debug build after WL#9764.

Fix
===
Both mysql_mutex_destroy and mysql_cond_destroy are called to
destroy the mutex and condition objects in ~Commit_order_manager.

Author: Libing Song

sql/rpl_slave_commit_order_manager.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -29,6 +29,16 @@ Commit_order_manager::Commit_order_manager(uint32 worker_numbers)
   }
 }
 
+Commit_order_manager::~Commit_order_manager()
+{
+  mysql_mutex_destroy(&m_mutex);
+
+  for (uint32 i= 0; i < m_workers.size(); i++)
+  {
+    mysql_cond_destroy(&m_workers[i].cond);
+  }
+}
+
 void Commit_order_manager::register_trx(Slave_worker *worker)
 {
   DBUG_ENTER("Commit_order_manager::register_trx");

sql/rpl_slave_commit_order_manager.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@ class Commit_order_manager
 {
 public:
   Commit_order_manager(uint32 worker_numbers);
-  ~Commit_order_manager() {}
+  ~Commit_order_manager();
 
   /**
     Register the worker into commit order queue when coordinator dispatches a
@@ -124,6 +124,10 @@ class Commit_order_manager
   }
 
   uint32 queue_front() { return queue_head; }
+
+  // Copy constructor is not implemented
+  Commit_order_manager(const Commit_order_manager&);
+  Commit_order_manager& operator=(const Commit_order_manager&);
 };
 
 inline bool has_commit_order_manager(THD *thd)