Can async_write cause segmentation fault when this is deleted?

Question

I am using Boost to send data over TCP with async_write :

std::shared_ptr<std::vector<std::string>::iterator> iter = std::make_shared<std::vector<std::string>::iterator>(this->m_vDataToWrite.begin());

boost::asio::async_write(this->socket_, boost::asio::buffer(*message),
    boost::asio::transfer_all(), boost::bind(&Session::writeHandler,
           this, boost::asio::placeholders::error,
           boost::asio::placeholders::bytes_transferred(),
           message, 
           iter
           ));



    // ...

    void Session::writeHandler(const boost::system::error_code &error, std::size_t bytes_transferred, std::shared_ptr<std::string> message, std::shared_ptr<std::vector<std::string>::iterator> it)
    {
        if(error)
        {
            std::cout << "Write handler error: " << error.message() << std::endl;
            this->disconnect();
            delete this;
            return;
        }
//....

Notice the delete this; in the write handler.

So when there is an error while sending the data, the session will disconnect and then delete itself. However, there is a segmentation fault after writeHandler has returned. Could it be because I am deleting this although it is captured in async_write ?

Answer 1

Once you delete this any access to the object is invalid. It doesn't matter if you've copied/captured the pointer anywhere else.