Initial commit for GitHub migration based on spice2x-25-03-03

src/spice2x/util/threadpool.h

@@ -0,0 +1,70 @@
+#pragma once
+
+#include <vector>
+#include <queue>
+#include <memory>
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+#include <future>
+#include <functional>
+#include <stdexcept>
+
+class ThreadPool {
+private:
+    std::vector<std::thread> threads;
+    std::queue<std::function<void()>> queue;
+    std::mutex mut;
+    std::condition_variable cv;
+    bool exit = false;
+
+public:
+
+    ThreadPool(size_t size) {
+        for (size_t i = 0; i < size; i++) {
+            threads.emplace_back([this] {
+                while (true) {
+                    std::function<void()> func;
+                    std::unique_lock<std::mutex> lock(mut);
+                    cv.wait(lock, [this] { return exit || !queue.empty(); });
+                    if (exit && queue.empty()) return;
+                    func = std::move(queue.front());
+                    queue.pop();
+                    lock.unlock();
+                    func();
+                }
+            });
+        }
+    }
+
+    ~ThreadPool() {
+        exit = true;
+        mut.lock();
+        mut.unlock();
+        cv.notify_all();
+        for (auto &thread : threads) {
+            if (thread.joinable()) {
+                thread.join();
+            }
+        }
+    }
+
+    size_t queue_size() {
+        std::unique_lock<std::mutex> lock(mut);
+        return queue.size();
+    }
+
+    template<class T, class... Args>
+    auto add(T&& func, Args&&... args)
+    -> std::future<typename std::result_of<T(Args...)>::type> {
+        using ret_t = typename std::result_of<T(Args...)>::type;
+        auto task = std::make_shared<std::packaged_task<ret_t()>>(
+                std::bind(std::forward<T>(func), std::forward<Args>(args)...));
+        std::future<ret_t> fut = task->get_future();
+        std::unique_lock<std::mutex> lock(mut);
+        queue.emplace([task] () { (*task)(); });
+        lock.unlock();
+        cv.notify_one();
+        return fut;
+    }
+};