Move c++ code from my_atomic.h to my_atomic_wrapper.h

This is because it breaks code that is using extern "C" when including
my_atomic, which is the case with ha_s3.cc

include/my_atomic.h

@@ -169,49 +169,4 @@
 #define my_atomic_casptr_strong_explicit(P, E, D, S, F) \
   my_atomic_casptr((P), (E), (D))
 #endif
-
-#ifdef __cplusplus
-#include <atomic>
-/**
-  A wrapper for std::atomic, defaulting to std::memory_order_relaxed.
-
-  When it comes to atomic loads or stores at std::memory_order_relaxed
-  on IA-32 or AMD64, this wrapper is only introducing some constraints
-  to the C++ compiler, to prevent some optimizations of loads or
-  stores.
-
-  On POWER and ARM, atomic loads and stores involve different instructions
-  from normal loads and stores and will thus incur some overhead.
-
-  Because atomic read-modify-write operations will always incur
-  overhead, we intentionally do not define
-  operator++(), operator--(), operator+=(), operator-=(), or similar,
-  to make the overhead stand out in the users of this code.
-*/
-template <typename Type> class Atomic_relaxed
-{
-  std::atomic<Type> m;
-public:
-  Atomic_relaxed(const Atomic_relaxed<Type> &rhs)
-  { m.store(rhs, std::memory_order_relaxed); }
-  Atomic_relaxed(Type val) : m(val) {}
-  Atomic_relaxed() {}
-
-  operator Type() const { return m.load(std::memory_order_relaxed); }
-  Type operator=(const Type val)
-  { m.store(val, std::memory_order_relaxed); return val; }
-  Type operator=(const Atomic_relaxed<Type> &rhs) { return *this= Type{rhs}; }
-  Type fetch_add(const Type i, std::memory_order o= std::memory_order_relaxed)
-  { return m.fetch_add(i, o); }
-  Type fetch_sub(const Type i, std::memory_order o= std::memory_order_relaxed)
-  { return m.fetch_sub(i, o); }
-  bool compare_exchange_strong(Type& i1, const Type i2,
-                               std::memory_order o1= std::memory_order_relaxed,
-                               std::memory_order o2= std::memory_order_relaxed)
-  { return m.compare_exchange_strong(i1, i2, o1, o2); }
-  Type exchange(const Type i, std::memory_order o= std::memory_order_relaxed)
-  { return m.exchange(i, o); }
-};
-#endif /* __cplusplus */
-
 #endif /* MY_ATOMIC_INCLUDED */

include/my_atomic_wrapper.h

@@ -0,0 +1,58 @@
+/* Copyright (c) 2020, MariaDB
+
+   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 Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+#ifdef __cplusplus
+#include <atomic>
+/**
+  A wrapper for std::atomic, defaulting to std::memory_order_relaxed.
+
+  When it comes to atomic loads or stores at std::memory_order_relaxed
+  on IA-32 or AMD64, this wrapper is only introducing some constraints
+  to the C++ compiler, to prevent some optimizations of loads or
+  stores.
+
+  On POWER and ARM, atomic loads and stores involve different instructions
+  from normal loads and stores and will thus incur some overhead.
+
+  Because atomic read-modify-write operations will always incur
+  overhead, we intentionally do not define
+  operator++(), operator--(), operator+=(), operator-=(), or similar,
+  to make the overhead stand out in the users of this code.
+*/
+template <typename Type> class Atomic_relaxed
+{
+  std::atomic<Type> m;
+public:
+  Atomic_relaxed(const Atomic_relaxed<Type> &rhs)
+  { m.store(rhs, std::memory_order_relaxed); }
+  Atomic_relaxed(Type val) : m(val) {}
+  Atomic_relaxed() {}
+
+  operator Type() const { return m.load(std::memory_order_relaxed); }
+  Type operator=(const Type val)
+  { m.store(val, std::memory_order_relaxed); return val; }
+  Type operator=(const Atomic_relaxed<Type> &rhs) { return *this= Type{rhs}; }
+  Type fetch_add(const Type i, std::memory_order o= std::memory_order_relaxed)
+  { return m.fetch_add(i, o); }
+  Type fetch_sub(const Type i, std::memory_order o= std::memory_order_relaxed)
+  { return m.fetch_sub(i, o); }
+  bool compare_exchange_strong(Type& i1, const Type i2,
+                               std::memory_order o1= std::memory_order_relaxed,
+                               std::memory_order o2= std::memory_order_relaxed)
+  { return m.compare_exchange_strong(i1, i2, o1, o2); }
+  Type exchange(const Type i, std::memory_order o= std::memory_order_relaxed)
+  { return m.exchange(i, o); }
+};
+#endif /* __cplusplus */

storage/innobase/include/srv0mon.h

@@ -38,6 +38,7 @@ Created 12/15/2009	Jimmy Yang
 
 #include <stdint.h>
 #include "my_atomic.h"
+#include "my_atomic_wrapper.h"
 
 /** Possible status values for "mon_status" in "struct monitor_value" */
 enum monitor_running_status {