- Mutex
- lock
Counter with threads (local counting)
- This solution does the work locally and updates the shared variable only at the end
examples/threads/counter-with-mutex-local/src/main.rs
fn main() { let limit = 1_000_000; let threads = 10; let result = count_with_mutex(threads, limit); println!("{}", result); assert_eq!(result, limit * threads); } fn count_with_mutex(threads: i32, limit: i32) -> i32 { let counter = std::sync::Mutex::new(0); std::thread::scope(|scope| { for _ in 0..threads { scope.spawn(|| { println!("Start {:?}", std::thread::current().id()); let mut my_counter = 0; for _ in 0..limit { my_counter += 1; } let mut guard = counter.lock().unwrap(); *guard += my_counter; }); } }); counter.into_inner().unwrap() }