Luna/kernel/src/thread/Spinlock.h

#pragma once
#include <luna/Atomic.h>

class Spinlock
{
  public:
    void lock();
    void unlock();

    bool is_locked() const
    {
        return m_lock.load() != -1;
    }

    // Call this before use if the Spinlock is a global variable.
    void init()
    {
        m_lock = -1;
    }

  private:
    Atomic<int> m_lock{-1};
};

template <typename T> class LockedValue
{
    struct LockedValueGuard
    {
        LockedValueGuard(LockedValue& value_ref) : m_value_ref(value_ref)
        {
        }

        ~LockedValueGuard()
        {
            m_value_ref.m_lock.unlock();
        }

        T& ref()
        {
            return m_value_ref.m_value;
        }

        void set(const T& other)
        {
            ref() = other;
        }

        T* operator->()
        {
            return &ref();
        }

        T& operator*()
        {
            return ref();
        }

      private:
        LockedValue& m_value_ref;
    };

  public:
    LockedValue() : m_value()
    {
    }

    LockedValue(T value) : m_value(value)
    {
    }

    // Call this before use if the LockedValue is a global variable.
    void init()
    {
        m_lock.init();
    }

    LockedValueGuard lock()
    {
        m_lock.lock();
        return {*this};
    }

  private:
    T m_value;
    Spinlock m_lock;
};