C++线程池

这是一个简单的线程池，用C++标准实现

#include <thread>
#include <vector>
#include <queue>
#include <mutex>
#include <condition_variable>
#include <future>
#include <functional>
#include <stdexcept>

class ThreadPool {
public:
  ThreadPool(size_t numThreads);
  ~ThreadPool();

  template<typename F, typename... Args>
  auto enqueue(F&& f, Args&&... args) -> std::future<decltype(f(args...))>;

private:
  std::vector<std::thread> threads;
  std::queue<std::function<void()>> tasks;

  std::mutex queueMutex;
  std::condition_variable condition;
  bool stop{false};
};

// 线程运行函数
void ThreadPool::workerThread() {
  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();
  }
}

// 提交任务
template<typename F, typename... Args>
auto ThreadPool::enqueue(F&& f, Args&&... args) -> std::future<decltype(f(args...))> {
  // 包装任务
  auto task = std::make_shared<std::packaged_task<decltype(f(args...))(Args...)>>(
    std::bind(std::forward<F>(f), std::forward<Args>(args)...)
  );

  std::future<decltype(f(args...))> future = task->get_future();
  {
    std::unique_lock<std::mutex> lock(queueMutex);

    // 添加任务到队列
    tasks.emplace([task]() { (*task)(); });
  }
  condition.notify_one();
  return future;
}

// 线程池构造与析构
ThreadPool::ThreadPool(size_t numThreads) {
  // 启动指定数量的线程
  for(size_t i = 0; i < numThreads; ++i) {
    threads.emplace_back(
      std::thread(&ThreadPool::workerThread, this)
    ); 
  }
}

ThreadPool::~ThreadPool() {
  {
    std::unique_lock<std::mutex> lock(queueMutex);
    stop = true;
  }
  condition.notify_all();

  for(std::thread &thread : threads) {
    thread.join(); 
  }
}