When sharing mutable data between threads, use the Arc<RwLock<T>> pattern to ensure thread safety. Arc provides thread-safe reference counting for sharing ownership across thread boundaries, while RwLock enables controlled mutation of the shared data.

This pattern is particularly important when:

// Instead of this (not thread-safe for mutation):
let model = Arc::new(MyModel::new());

// Use this pattern for thread-safe mutation:
let model = Arc::new(RwLock::new(MyModel::new()));

// Reading from the shared resource:
let data = model.read().unwrap().get_data();

// Writing to the shared resource:
model.write().unwrap().update_data();

When working with RwLock, unwrap() is generally acceptable for lock acquisition failures as they indicate a thread panic (unrecoverable state), but consider proper error handling in production code where appropriate. Remember that RwLock allows multiple simultaneous readers but only one writer, optimizing for read-heavy workloads.