1// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
2// Distributed under the MIT License (http://opensource.org/licenses/MIT)
3
4#pragma once
5
6#include <atomic>
7#include <utility>
8// null, no cost dummy "mutex" and dummy "atomic" int
9
10namespace spdlog {
11namespace details {
12struct null_mutex
13{
14 void lock() const {}
15 void unlock() const {}
16};
17
18struct null_atomic_int
19{
20 int value;
21 null_atomic_int() = default;
22
23 explicit null_atomic_int(int new_value)
24 : value(new_value)
25 {}
26
27 int load(std::memory_order = std::memory_order_relaxed) const
28 {
29 return value;
30 }
31
32 void store(int new_value, std::memory_order = std::memory_order_relaxed)
33 {
34 value = new_value;
35 }
36
37 int exchange(int new_value, std::memory_order = std::memory_order_relaxed)
38 {
39 std::swap(new_value, value);
40 return new_value; // return value before the call
41 }
42};
43
44} // namespace details
45} // namespace spdlog
46