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diff --git a/contrib/libs/libmysql_r/include/my_atomic.h b/contrib/libs/libmysql_r/include/my_atomic.h
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+++ b/contrib/libs/libmysql_r/include/my_atomic.h
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+#ifndef MY_ATOMIC_INCLUDED
+#define MY_ATOMIC_INCLUDED
+
+/* Copyright (c) 2006, 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, version 2.0,
+   as published by the Free Software Foundation.
+
+   This program is also distributed with certain software (including
+   but not limited to OpenSSL) that is licensed under separate terms,
+   as designated in a particular file or component or in included license
+   documentation.  The authors of MySQL hereby grant you an additional
+   permission to link the program and your derivative works with the
+   separately licensed software that they have included with MySQL.
+
+   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, version 2.0, 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 02110-1301  USA */
+
+/**
+  @file include/my_atomic.h
+*/
+
+#if defined(_MSC_VER)
+
+#include <windows.h>
+
+/*
+  my_yield_processor (equivalent of x86 PAUSE instruction) should be used
+  to improve performance on hyperthreaded CPUs. Intel recommends to use it in
+  spin loops also on non-HT machines to reduce power consumption (see e.g
+  http://softwarecommunity.intel.com/articles/eng/2004.htm)
+
+  Running benchmarks for spinlocks implemented with InterlockedCompareExchange
+  and YieldProcessor shows that much better performance is achieved by calling
+  YieldProcessor in a loop - that is, yielding longer. On Intel boxes setting
+  loop count in the range 200-300 brought best results.
+ */
+#define YIELD_LOOPS 200
+
+static inline int my_yield_processor() {
+  int i;
+  for (i = 0; i < YIELD_LOOPS; i++) {
+    YieldProcessor();
+  }
+  return 1;
+}
+
+#define LF_BACKOFF my_yield_processor()
+
+#else  // !defined(_MSC_VER)
+
+#define LF_BACKOFF (1)
+
+#endif
+
+#endif /* MY_ATOMIC_INCLUDED */