Creating threads in Rust - Try It Yourself

Creating threads

📖 Scenario: You are building a simple Rust program that uses threads to run tasks in parallel. This is useful when you want your program to do multiple things at the same time, like cooking and cleaning in a kitchen.

🎯 Goal: Create a Rust program that starts a new thread to print a message, while the main thread prints another message. This will show how threads work together.

📋 What You'll Learn

Create a new thread using std::thread::spawn

Use a closure to define the thread's task

Print a message from the new thread

Print a message from the main thread

Wait for the new thread to finish using join

💡 Why This Matters

🌍 Real World

Threads let programs do many things at once, like downloading files while showing a progress bar.

💼 Career

Understanding threads is important for building fast and responsive software in many jobs, including systems programming and web servers.

1

Create a new thread

Write code to create a new thread using std::thread::spawn that runs a closure printing "Hello from the new thread!". Store the thread handle in a variable called handle.

Rust

use std::thread;

// Your code here

Hint

Use thread::spawn with a closure || { ... } to create the thread.

2

Print from the main thread

Add a line to print "Hello from the main thread!" in the main thread after creating the new thread.

Rust

use std::thread;

fn main() {
    let handle = thread::spawn(|| {
        println!("Hello from the new thread!");
    });

    // Your code here
}

Hint

Use println! to print the message in the main thread.

3

Wait for the new thread to finish

Call handle.join().unwrap() to wait for the new thread to finish before the program ends.

Rust

use std::thread;

fn main() {
    let handle = thread::spawn(|| {
        println!("Hello from the new thread!");
    });

    println!("Hello from the main thread!");

    // Your code here
}

Hint

Use join() on the thread handle to wait for the thread to finish.

4

Print the final output

Run the program and print the output messages from both threads.

Rust

use std::thread;

fn main() {
    let handle = thread::spawn(|| {
        println!("Hello from the new thread!");
    });

    println!("Hello from the main thread!");

    handle.join().unwrap();

    // Your code here
}

Hint

Run the program to see both messages printed. The order may vary because threads run in parallel.