rust global variables

Rust Global Variables

In Rust, global variables are not directly supported. Rust encourages a more controlled approach to variable scoping and ownership. Instead of using global variables, Rust promotes the use of modules and associated functions to encapsulate and manage state.

However, if you need to share state across multiple modules or threads, you can use Rust's concurrency primitives like Arc (Atomic Reference Counting) or Mutex (Mutual Exclusion). These allow you to safely share data between multiple threads or modules.

Here's an example of using Arc to share state between multiple threads:

use std::sync::Arc;
use std::thread;

fn main() {
    let shared_data = Arc::new(42);

    let thread1 = {
        let shared_data = Arc::clone(&shared_data);
        thread::spawn(move || {
            // Access shared_data in thread 1
            println!("Thread 1: {}", *shared_data);
        })
    };

    let thread2 = {
        let shared_data = Arc::clone(&shared_data);
        thread::spawn(move || {
            // Access shared_data in thread 2
            println!("Thread 2: {}", *shared_data);
        })
    };

    thread1.join().unwrap();
    thread2.join().unwrap();
}

In this example, the shared_data variable is wrapped in an Arc, which allows multiple threads to have shared ownership of the data. Each thread can access the shared data without causing data races or other concurrency issues.

Remember that using shared mutable state can introduce complexity and potential issues like data races. It's generally recommended to use Rust's ownership and borrowing system to manage state in a more controlled and safe manner.