From da79c9fdefdba12d973478285496e356cb53edfd Mon Sep 17 00:00:00 2001
From: GeorgH93 <git@georgh93.eu>
Date: Tue, 31 Oct 2023 16:19:22 +0100
Subject: [PATCH] Add ThreadSafeQueue

---
 .../Concurent/Containers/ThreadSafeQueue.hpp  | 119 ++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 openVulkanoCpp/Data/Concurent/Containers/ThreadSafeQueue.hpp

diff --git a/openVulkanoCpp/Data/Concurent/Containers/ThreadSafeQueue.hpp b/openVulkanoCpp/Data/Concurent/Containers/ThreadSafeQueue.hpp
new file mode 100644
index 0000000..4ec4d60
--- /dev/null
+++ b/openVulkanoCpp/Data/Concurent/Containers/ThreadSafeQueue.hpp
@@ -0,0 +1,119 @@
+/*
+ * 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 https://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include <atomic>
+#include <condition_variable>
+#include <optional>
+#include <mutex>
+#include <thread>
+#include <queue>
+
+namespace OpenVulkano
+{
+	template<typename T>
+	class ThreadSafeQueue final
+	{
+		std::queue<T> m_queue;
+		mutable std::mutex m_mutex;
+		std::condition_variable m_newDataAvailable;
+		bool m_end = false;
+		std::atomic_int m_waiting = 0;
+
+		inline std::optional<T> PopInternal()
+		{
+			if (m_queue.empty()) return {};
+			T tmp = std::move(m_queue.front());
+			m_queue.pop();
+			return tmp;
+		}
+
+	public:
+		ThreadSafeQueue() = default;
+
+		ThreadSafeQueue(const ThreadSafeQueue<T> &) = delete ;
+		ThreadSafeQueue& operator=(const ThreadSafeQueue<T> &) = delete ;
+
+		ThreadSafeQueue(ThreadSafeQueue<T>&& other) noexcept
+		{
+			std::scoped_lock lock(m_mutex, other.m_mutex);
+			m_queue = std::move(other.m_queue);
+		}
+
+		~ThreadSafeQueue()
+		{
+			m_end = true;
+			m_newDataAvailable.notify_all();
+			while (m_waiting) { std::this_thread::yield(); }
+		}
+
+		size_t Size() const
+		{
+			std::lock_guard lock(m_mutex);
+			return m_queue.size();
+		}
+
+		bool Empty() const
+		{
+			std::lock_guard lock(m_mutex);
+			return m_queue.empty();
+		}
+
+		std::optional<T> Pop()
+		{
+			std::unique_lock lock(m_mutex);
+			return PopInternal();
+		}
+
+		std::optional<T> PopWait()
+		{
+			m_waiting++;
+			std::unique_lock lock(m_mutex);
+			m_newDataAvailable.wait(lock, [this]() { return !m_queue.empty() || m_end; });
+			auto tmp = PopInternal();
+			m_waiting--;
+			return tmp;
+		}
+
+		std::optional<T> Peak() const
+		{
+			std::lock_guard lock(m_mutex);
+			if (m_queue.empty()) return {};
+			return m_queue.front();
+		}
+
+		size_t Push(const T& item)
+		{
+			std::unique_lock lock(m_mutex);
+			if (m_end) return 0;
+			m_queue.push(item);
+			m_newDataAvailable.notify_one();
+			return m_queue.size();
+		}
+
+		size_t Push(T&& item)
+		{
+			std::unique_lock lock(m_mutex);
+			if (m_end) return 0;
+			m_queue.push(std::forward<T>(item));
+			m_newDataAvailable.notify_one();
+			return m_queue.size();
+		}
+
+		ThreadSafeQueue& operator=(ThreadSafeQueue<T>&& other) noexcept
+		{
+			if (this != &other)
+			{
+				std::scoped_lock lock(m_mutex, other.m_mutex);
+
+				m_queue = std::move(other.m_queue);
+				m_newDataAvailable.notify_one();
+			}
+			return *this;
+		}
+	};
+}