状态共享 全局变量 atomic 1 2 3 4 5 6use std::sync::atomic::{AtomicUsize, Ordering}; static GLOBAL_THREAD_COUNT: AtomicUsize = AtomicUsize::new(0); let old_thread_count = GLOBAL_THREAD_COUNT.fetch_add(1, Ordering::SeqCst); println!("live threads: {}", old_thread_count + 1); once_cell https://github.com/matklad/once_cell lazy_static https://github.com/rust-lang-nursery/lazy-static.rs