Thread safe c++ Timer

timer.h

#include <condition_variable>
#include <functional>
#include <memory>
#include <shared_mutex>
#include <thread>
#include <chrono>

template <class Rep, class Period> class Timer {
public:
  using Callback = std::function<void()>;

  Timer(const std::chrono::duration<Rep, Period> &duration,
        const Callback &callback) {
    std::thread([=]() {
      std::mutex mutex;
      std::unique_lock lk(mutex);
      do {
        std::thread([=]() {
          std::shared_lock lk(*mutex_);
          callback();
        }).detach();
      } while (!cv_->wait_for(lk, duration, [=]() { return *stop_; }));
    }).detach();
  }

  void Stop(bool sync = false) {
    *stop_ = true;
    cv_->notify_all();
    if (sync) {
      std::unique_lock lk(*mutex_);
    }
  }

  ~Timer() { Stop(true); }

private:
  std::shared_ptr<std::condition_variable> cv_{
      std::make_shared<std::condition_variable>()};
  std::shared_ptr<bool> stop_{std::make_shared<bool>(false)};
  std::shared_ptr<std::shared_mutex> mutex_{
      std::make_shared<std::shared_mutex>()};
};