You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: fault_all_handler.rs
    path of file: ./repos/firecracker/src/firecracker/examples/uffd
    
    the code of the file until where you have to start completion: // Copyright 2024 Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

//! Provides functionality for a userspace page fault handler
//! which loads the whole region from the backing memory file
//! when a page fault occurs.

mod uffd_utils;

use std::fs::File;
use std::os::unix::net::UnixListener;

use uffd_utils::{Runtime, UffdHandler};

fn main() {
    let mut args = std::env::args();
    let uffd_sock_path = args.nth(1).expect("No socket path given");
    let mem_file_path = args.next().expect("No memory file given");

    let file = File::open(mem_file_path).expect("Cannot open memfile");

    // Get Uffd from UDS. We'll use the uffd to handle PFs for Firecracker.
    let listener = UnixListener::bind(uffd_sock_path).expect("Cannot bind to socket path");
    let (stream, _) = listener.accept().expect("Cannot listen on UDS socket");

    let mut runtime = Runtime::new(stream, file);
    runtime.run(|uffd_handler: &mut UffdHandler| {
        // Read an event from the userfaultfd.
        let event = uffd_handler
            .read_e
    
fn main() {
    let mut args = std::env::args();
    let uffd_sock_path = args.nth(1).expect("No socket path given");
    let mem_file_path = args.next().expect("No memory file given");

    let file = File::open(mem_file_path).expect("Cannot open memfile");

    // Get Uffd from UDS. We'll use the uffd to handle PFs for Firecracker.
    let listener = UnixListener::bind(uffd_sock_path).expect("Cannot bind to socket path");
    let (stream, _) = listener.accept().expect("Cannot listen on UDS socket");

    let mut runtime = Runtime::new(stream, file);
    runtime.run(|uffd_handler: &mut UffdHandler| {
        // Read an event from the userfaultfd.
        let event = uffd_handler
            .read_event()
            .expect("Failed to read uffd_msg")
            .expect("uffd_msg not ready");

        match event {
            userfaultfd::Event::Pagefault { .. } => {
                for region in uffd_handler.mem_regions.clone() {
                    uffd_handler
                        .serve_pf(region.mapping.base_host_virt_addr as _, region.mapping.size)
                }
            }
            _ => panic!("Unexpected event on userfaultfd"),
        }
    });
}