How can the register_shutdown_function and ignore_user_abort PHP functions be used to manage session destruction upon browser window closure?

When a user closes their browser window, the PHP session may not be properly destroyed, leading to potential security risks. To manage session destruction upon browser window closure, we can use the `register_shutdown_function` function to register a callback function that will be executed when the script finishes execution, regardless of how it ends. Additionally, we can use the `ignore_user_abort` function to ensure that the script continues running even if the user aborts the request.

<?php
// Register a shutdown function to destroy the session
register_shutdown_function(function() {
    session_destroy();
});

// Ignore user abort to ensure script continues running
ignore_user_abort(true);

// Start the session
session_start();

// Your PHP code here
?>