Function MyAtomicTryLock

util/generic/singleton.cpp:10–13

namespace {
    static inline bool MyAtomicTryLock(std::atomic<size_t>& a, size_t v) noexcept {
        size_t zero = 0;
        return a.compare_exchange_strong(zero, v);
    }

    static inline bool MyAtomicTryAndTryLock(std::atomic<size_t>& a, size_t v) noexcept {
        return a.load(std::memory_order_acquire) == 0 && MyAtomicTryLock(a, v);