Memory management issues when refactoring a legacy C++ application using Boost libraries
I'm converting an old project and I've been banging my head against this for hours... Recently started working with a legacy C++ application that's heavily reliant on Boost libraries, specifically Boost.Asio for asynchronous I/O alongside Boost.SmartPtr for memory management. During my refactoring efforts, particularly while transitioning to a more modern design pattern, I've noticed some unexpected memory management issues. My goal is to replace raw pointers with smart pointers everywhere to improve safety and readability. To give some context, I've replaced several instances of raw pointers with `std::shared_ptr` and `std::unique_ptr`, following best practices. However, after running the application, Valgrind raised concerns about potential memory leaks that seem to originate from the way I handle asynchronous tasks. Here's a snippet of the code where I'm struggling: ```cpp #include <boost/asio.hpp> #include <boost/shared_ptr.hpp> #include <iostream> class TaskProcessor { public: void start() { boost::asio::io_context io; auto task = boost::make_shared<Task>(io); task->execute(); io.run(); } }; class Task { public: Task(boost::asio::io_context& io) : timer_(io) { timer_.expires_from_now(boost::chrono::seconds(1)); timer_.async_wait(std::bind(&Task::handle_timeout, this, std::placeholders::_1)); } void execute() { // Task execution logic } private: void handle_timeout(const boost::system::error_code& e) { if (!e) { std::cout << "Task executed!" << std::endl; } } boost::asio::steady_timer timer_; }; ``` When performing the refactor, I ensured that the `Task` objects are managed by `boost::shared_ptr`, but I'm still receiving warnings indicating that some of these shared pointers are not being released properly. From what I've read, it might be due to circular references or the way I'm binding the `handle_timeout` method. I've tried a few different approaches: 1. Switching from `async_wait` to a lambda function to break potential circular dependencies, but this led to compilation errors. 2. Utilizing weak pointers in an attempt to prevent circular references, but the application still flagged memory leaks. 3. Carefully checking that all tasks are properly completed before the `io_context` goes out of scope, yet I still see warnings from Valgrind. Is there a recommended way to handle these callbacks without running into memory leaks? Any insights into using smart pointers with Boost in this context would be greatly appreciated. Are there specific patterns or practices that can help avoid these pitfalls? I'm working on a application that needs to handle this. Thanks for any help you can provide! This is part of a larger CLI tool I'm building. Am I missing something obvious?