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| -rw-r--r-- | src/doc/tarpl/races.md | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/src/doc/tarpl/races.md b/src/doc/tarpl/races.md index 240e4aca7f6..2ad62c14a80 100644 --- a/src/doc/tarpl/races.md +++ b/src/doc/tarpl/races.md @@ -25,7 +25,7 @@ race condition can't violate memory safety in a Rust program on its own. Only in conjunction with some other unsafe code can a race condition actually violate memory safety. For instance: -```rust +```rust,norun use std::thread; use std::sync::atomic::{AtomicUsize, Ordering}; use std::sync::Arc; @@ -54,6 +54,24 @@ thread::spawn(move || { // program execution (panicing is rarely correct) depends on order of // thread execution. println!("{}", data[idx.load(Ordering::SeqCst)]); +``` + +```rust,norun +use std::thread; +use std::sync::atomic::{AtomicUsize, Ordering}; +use std::sync::Arc; + +let data = vec![1, 2, 3, 4]; + +let idx = Arc::new(AtomicUsize::new(0)); +let other_idx = idx.clone(); + +// `move` captures other_idx by-value, moving it into this thread +thread::spawn(move || { + // It's ok to mutate idx because this value + // is an atomic, so it can't cause a Data Race. + other_idx.fetch_add(10, Ordering::SeqCst); +}); if idx.load(Ordering::SeqCst) < data.len() { unsafe { |