MDEV-21452: Replace ib_mutex_t with mysql_mutex_t

SHOW ENGINE INNODB MUTEX functionality is completely removed,
as are the InnoDB latching order checks.

We will enforce innodb_fatal_semaphore_wait_threshold
only for dict_sys.mutex and lock_sys.mutex.

dict_sys_t::mutex_lock(): A single entry point for dict_sys.mutex.

lock_sys_t::mutex_lock(): A single entry point for lock_sys.mutex.

FIXME: srv_sys should be removed altogether; it is duplicating tpool
functionality.

fil_crypt_threads_init(): To prevent SAFE_MUTEX warnings, we must
not hold fil_system.mutex.

fil_close_all_files(): To prevent SAFE_MUTEX warnings for
fil_space_destroy_crypt_data(), we must not hold fil_system.mutex
while invoking fil_space_free_low() on a detached tablespace.

1 files changed, 3 insertions, 3 deletions

diff --git a/storage/innobase/read/read0read.cc b/storage/innobase/read/read0read.cc
index 92504546130..be37a9f9e5f 100644
--- a/storage/innobase/read/read0read.cc
+++ b/storage/innobase/read/read0read.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2018, 2019, MariaDB Corporation.
+Copyright (c) 2018, 2020, MariaDB Corporation.
 
 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 the Free Software
@@ -226,10 +226,10 @@ void ReadView::open(trx_t *trx)
       m_open.store(true, std::memory_order_relaxed);
     else
     {
-      mutex_enter(&m_mutex);
+      mysql_mutex_lock(&m_mutex);
       snapshot(trx);
       m_open.store(true, std::memory_order_relaxed);
-      mutex_exit(&m_mutex);
+      mysql_mutex_unlock(&m_mutex);
     }
   }
 }