实现异步回调机制，处理回调函数中出现的异常，并检查连接是否正常关闭。以下是示例代码：

void handle_accept(Session::Pointer session, const boost::system::error_code& error) { if (!error) { session->start(); } else if (error != boost::asio::error::operation_aborted) { // 处理异常情况 }

start_accept(session->get_io_service());

}

void start_accept(boost::asio::io_service& io_service) { Session::Pointer session(new Session(io_service));

acceptor.async_accept(session->socket(), boost::bind(handle_accept, session, boost::asio::placeholders::error));

}

void Session::start() { boost::asio::async_read(socket_, boost::asio::buffer(data_), boost::asio::transfer_at_least(1), boost::bind(&Session::handle_read, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred));

// ...

timer_.expires_from_now(boost::posix_time::seconds(60));
timer_.async_wait(boost::bind(&Session::handle_timeout, shared_from_this(), boost::asio::placeholders::error));

}

void Session::handle_read(const boost::system::error_code& error, size_t bytes_transferred) { if (!error) { // 处理接收到的数据 } else { // 处理异常情况 } }

void Session::handle_timeout(const boost::system::error_code& error) { if (!error) { socket_.close(); } }