mirror of
https://github.com/matrix-construct/construct
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37 lines
935 B
C++
37 lines
935 B
C++
// The Construct
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//
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// Copyright (C) The Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2020 Jason Volk <jason@zemos.net>
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//
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// Permission to use, copy, modify, and/or distribute this software for any
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// purpose with or without fee is hereby granted, provided that the above
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// copyright notice and this permission notice is present in all copies. The
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// full license for this software is available in the LICENSE file.
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#pragma once
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#define HAVE_IRCD_UTIL_COMPARE_EXCHANGE_H
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namespace ircd {
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inline namespace util
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{
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template<class T>
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bool compare_exchange(T &value, T &expect, T desire) noexcept;
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}}
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/// Non-atomic compare_exchange().
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template<class T>
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inline bool
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ircd::util::compare_exchange(T &value,
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T &expect,
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T desire)
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noexcept
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{
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const bool ret
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{
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value == expect
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};
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value = ret? desire: value;
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expect = ret? expect: value;
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return ret;
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}
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