# Testing speed improvements with threads

**examples/threads/threads-load-test/src/main.rs**

use std::time::Instant; use std::sync::mpsc; use std::thread; fn main() { let (tx, rx) = mpsc::channel(); let start = Instant::now(); //for n in 1..=10 { // println!("{n}: {}", fibonacci(n)); //} //let n = 43; // 42 2 sec, 43 3 sec //println!("{n}: {}", fibonacci(n)); //for _x in 1..=10 { // let n = 42; // println!("{n}: {}", fibonacci(n)); //} for _x in 1..=10 { let txr = tx.clone(); let n = 42; thread::spawn(move || { let res = fibonacci(n); txr.send(res.to_string()).unwrap(); println!("spawned thread finished"); }); } drop(tx); for received in rx { println!("Got: {}", received); } let duration = start.elapsed(); println!("Time elapsed in expensive_function() is: {:?}", duration); } fn fibonacci(n :u64) -> u64 { if n == 0 || n == 1 { return 1; } fibonacci(n - 1) + fibonacci(n - 2) }

TODO: what if there are variables in the main function? Can we read them from the threads? Can we write them? TODO: How to share workload? e.g. We would like to create 10,000 files with the sequnce number of the file being botht the content and the filename. TODO: What if we have a vector of 10,000 values and we would like to save each one of them in a separate file?