I am trying to understand different scenarios of cyclic references while using ioContext and shared_ptr and i stumbled into this.

In the code below class Test has a member variable shared_ptr<io_context>. When i make a the lambda inside of function ioContext post inside of async_wait i pass shared_from_this() {which is Test} in it. Imagine now ioContext is running in a different thread so the lambda gets added to internal ioContext queue. According to my understanding the lambda goes inside of ioContext internal queue and now there is a cyclic reference Test –> ioContext –> lambda –> Test.

Is my understanding correct here ? Is there any way to avoid this ?

https://coliru.stacked-crooked.com/a/586afa794d15ef8f

#include <boost/asio.hpp>
#include <boost/date_time.hpp>
#include <iostream>

std::string getTime()
{
    return std::string("[").append(to_iso_extended_string(boost::posix_time::microsec_clock::universal_time())).append("] ");
}

class Test : public std::enable_shared_from_this<Test> {
public:
    Test(const std::shared_ptr<boost::asio::io_context>& ioContext)
        : ioContext_(ioContext), timer_(*ioContext) {}

    void start() {
        std::cout << getTime() << "at startn";
        timer_.expires_after(std::chrono::seconds(3));
        timer_.async_wait([this, self=shared_from_this()](const boost::system::error_code& ec)
        {
            std::cout << getTime() << "Inside wait!n";
            if (!ec) 
            {
                ioContext_->post([this, self=shared_from_this()]()
                {
                    printInPost();
                });
            }
        });
    }

    void printInPost() {
        std::cout << getTime() << "I get printed!n";
    }

private:
    std::shared_ptr<boost::asio::io_context> ioContext_;
    boost::asio::steady_timer timer_;
};

int main() {
    std::shared_ptr<boost::asio::io_context> ioContext = std::make_shared<boost::asio::io_context>();
    std::shared_ptr<Test> myTest = std::make_shared<Test>(ioContext);
    
    myTest->start();
    
    ioContext->run();
}