Remove lf_mpsc, lf_spsc

Not practical

Utilities/lockless.h

@@ -146,189 +146,6 @@ public:
 	}
 };
 
-// Fixed-size single-producer single-consumer queue
-template <typename T, std::uint32_t N>
-class lf_spsc
-{
-	// If N is a power of 2, m_push/m_pop can safely overflow and the algorithm is simplified
-	static_assert(N && (1u << 31) % N == 0, "lf_spsc<> error: size must be power of 2");
-
-protected:
-	volatile std::uint32_t m_push{0};
-	volatile std::uint32_t m_pop{0};
-	T m_data[N]{};
-
-public:
-	constexpr lf_spsc() = default;
-
-	// Try to push (producer only)
-	template <typename T2>
-	bool try_push(T2&& data)
-	{
-		const std::uint32_t pos = m_push;
-
-		if (pos - m_pop >= N)
-		{
-			return false;
-		}
-
-		_mm_lfence();
-		m_data[pos % N] = std::forward<T2>(data);
-		_mm_sfence();
-		m_push = pos + 1;
-		return true;
-	}
-
-	// Try to get push pointer (producer only)
-	operator T*()
-	{
-		const std::uint32_t pos = m_push;
-
-		if (pos - m_pop >= N)
-		{
-			return nullptr;
-		}
-
-		_mm_lfence();
-		return m_data + (pos % N);
-	}
-
-	// Increment push counter (producer only)
-	void end_push()
-	{
-		const std::uint32_t pos = m_push;
-
-		if (pos - m_pop < N)
-		{
-			_mm_sfence();
-			m_push = pos + 1;
-		}
-	}
-
-	// Unsafe access
-	T& get_push(std::size_t i)
-	{
-		_mm_lfence();
-		return m_data[(m_push + i) % N];
-	}
-
-	// Try to pop (consumer only)
-	template <typename T2>
-	bool try_pop(T2& out)
-	{
-		const std::uint32_t pos = m_pop;
-
-		if (m_push - pos <= 0)
-		{
-			return false;
-		}
-
-		_mm_lfence();
-		out = std::move(m_data[pos % N]);
-		_mm_sfence();
-		m_pop = pos + 1;
-		return true;
-	}
-
-	// Increment pop counter (consumer only)
-	void end_pop()
-	{
-		const std::uint32_t pos = m_pop;
-
-		if (m_push - pos > 0)
-		{
-			_mm_sfence();
-			m_pop = pos + 1;
-		}
-	}
-
-	// Get size (consumer only)
-	std::uint32_t size() const
-	{
-		return m_push - m_pop;
-	}
-
-	// Direct access (consumer only)
-	T& operator [](std::size_t i)
-	{
-		_mm_lfence();
-		return m_data[(m_pop + i) % N];
-	}
-};
-
-// Fixed-size multi-producer single-consumer queue
-template <typename T, std::uint32_t N>
-class lf_mpsc : lf_spsc<T, N>
-{
-protected:
-	using lf_spsc<T, N>::m_push;
-	using lf_spsc<T, N>::m_pop;
-	using lf_spsc<T, N>::m_data;
-
-	enum : std::uint64_t
-	{
-		c_ack = 1ull << 0,
-		c_rel = 1ull << 32,
-	};
-
-	atomic_t<std::uint64_t> m_lock{0};
-
-	void release(std::uint64_t value)
-	{
-		// Push all pending elements at once when possible
-		if (value && value % c_rel == value / c_rel)
-		{
-			_mm_sfence();
-			m_push += value % c_rel;
-			m_lock.compare_and_swap_test(value, 0);
-		}
-	}
-
-public:
-	constexpr lf_mpsc() = default;
-
-	// Try to get push pointer
-	operator T*()
-	{
-		const std::uint64_t old = m_lock.fetch_add(c_ack);
-		const std::uint32_t pos = m_push;
-
-		if (old % N >= N || pos - m_pop >= N - (old % N))
-		{
-			release(m_lock.sub_fetch(c_ack));
-			return nullptr;
-		}
-
-		return m_data + ((pos + old) % N);
-	}
-
-	// Increment push counter (producer only)
-	void end_push()
-	{
-		release(m_lock.add_fetch(c_rel));
-	}
-
-	// Try to push
-	template <typename T2>
-	bool try_push(T2&& data)
-	{
-		if (T* ptr = *this)
-		{
-			*ptr = std::forward<T2>(data);
-			end_push();
-			return true;
-		}
-
-		return false;
-	}
-
-	// Enable consumer methods
-	using lf_spsc<T, N>::try_pop;
-	using lf_spsc<T, N>::end_pop;
-	using lf_spsc<T, N>::size;
-	using lf_spsc<T, N>::operator [];
-};
-
 // Helper type, linked list element
 template <typename T>
 class lf_queue_item final