created threadpool

cpp/src/threadpool.hpp

@@ -0,0 +1,73 @@
+#pragma once
+
+#include <condition_variable>
+#include <functional>
+#include <future>
+#include <iostream>
+#include <queue>
+#include <thread>
+#include <vector>
+
+class ThreadPool {
+  public:
+    ThreadPool(size_t numThreads) {
+        for (size_t i = 0; i < numThreads; ++i) {
+            workers.emplace_back([this] {
+                while (true) {
+                    std::function<void()> task;
+                    {
+                        std::unique_lock<std::mutex> lock(queueMutex);
+                        condition.wait(lock, [this] {
+                            return stop || !tasks.empty();
+                        });
+                        if (stop && tasks.empty())
+                            return;
+                        task = std::move(tasks.front());
+                        tasks.pop();
+                    }
+                    task();
+                }
+            });
+        }
+    }
+
+    template <class F, class... Args>
+    auto enqueue(F&& f, Args&&... args)
+        -> std::future<typename std::invoke_result<F, Args...>::type> {
+        using return_type = typename std::invoke_result<F, Args...>::type;
+
+        auto task = std::make_shared<std::packaged_task<return_type()>>(
+            std::bind(std::forward<F>(f), std::forward<Args>(args)...)
+        );
+
+        std::future<return_type> res = task->get_future();
+        {
+            std::unique_lock<std::mutex> lock(queueMutex);
+            tasks.emplace([task]() { (*task)(); });
+        }
+        condition.notify_one();
+        return res;
+    }
+
+    void waitAll() {
+        std::unique_lock<std::mutex> lock(queueMutex);
+        condition.wait(lock, [this] { return tasks.empty(); });
+    }
+
+    ~ThreadPool() {
+        {
+            std::unique_lock<std::mutex> lock(queueMutex);
+            stop = true;
+        }
+        condition.notify_all();
+        for (std::thread& worker : workers)
+            worker.join();
+    }
+
+  private:
+    std::vector<std::thread> workers;
+    std::queue<std::function<void()>> tasks;
+    std::mutex queueMutex;
+    std::condition_variable condition;
+    bool stop = false;
+};