AMutex.h

/*
 * AUI Framework - Declarative UI toolkit for modern C++20
 * Copyright (C) 2020-2024 Alex2772 and Contributors
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 
#pragma once
#include <atomic>
#include <mutex>
#include <shared_mutex>
#include <thread>
 
 
namespace aui::detail {
    template<typename T>
    struct MutexExtras: T {
    public:
        void lock() {
            T::lock();
        }
    };
}
 
struct AMutex: aui::detail::MutexExtras<std::mutex>{};
 
struct ARecursiveMutex: aui::detail::MutexExtras<std::recursive_mutex>{};
 
struct ASharedMutex: aui::detail::MutexExtras<std::shared_mutex> {
public:
    void lock_shared() {
        MutexExtras::lock_shared();
    }
};
 
 
class ASpinlockMutex {
public:
    void lock() {
        while (!try_lock()) {
            // busy-wait
        }
    }
 
    [[nodiscard]]
    bool try_lock() noexcept {
        return mState.exchange(LOCKED, std::memory_order_acquire) == UNLOCKED;
    }
 
    void unlock() noexcept {
        mState.store(UNLOCKED, std::memory_order_release);
    }
 
private:
    enum State { UNLOCKED, LOCKED };
    std::atomic<State> mState = UNLOCKED;
};
 
class AFakeMutex {
public:
    void lock() {}
    void try_lock() {}
    void unlock() {}
    void shared_lock() {}
    void try_shared_lock() {}
    void shared_unlock() {}
};