Rust: What is the difference between AtomicOrdering variants?

Ordering — memory ordering guarantees.

Variants:

• Relaxed — no ordering.
• Acquire — prevents reordering after.
• Release — prevents reordering before.
• AcqRel — both Acquire and Release.
• SeqCst — sequential consistency.

1use std::sync::atomic::{AtomicBool, Ordering};
2
3let flag = AtomicBool::new(false);
4
5// Writer
6flag.store(true, Ordering::Release);
7
8// Reader
9if flag.load(Ordering::Acquire) {
10    // Data is visible
11}

Key: Use SeqCst for simplicity, Acquire/Release for performance.