c++ shared_ptr cyclic references by capturing shared_from_this()

cyclic_references.cc

#include <atomic>
#include <functional>
#include <iostream>
#include <memory>
using namespace std;

static std::atomic_int idGenerator{0};

struct Object {
    int id;
    Object() : id(idGenerator++) { cout << "Create " << id << endl; }
    virtual ~Object() { cout << "Destroy " << id << endl; }
};

class Timer : public Object {
   public:
    void async_wait(function<void()> callback) {
        callback_ = callback;
        // Assume running callback_() in another thread
        callback_();
    }

   private:
    function<void()> callback_;
};

class Producer : public Object, public enable_shared_from_this<Producer> {
   public:
    void startTimer() {
        auto self = shared_from_this();
        timer_->async_wait([this, self] {});
    }

   private:
    std::shared_ptr<Timer> timer_{make_shared<Timer>()};
};

int main() {
    auto producer = make_shared<Producer>();
    producer->startTimer();
}

When executing timer.reset() logic in the doSomething method, which can avoid circular references.

The output mentioned above is produced under the premise of commenting timer.reset(). Is that right?

When executing timer.reset() logic in the doSomething method, which can avoid circular references.

Sorry it's my fault. I removed the doSomething() method now. Resetting the timer could avoid the cyclic reference.