Rust Arc

What is Rust Arc?

Rust's Arc, standing for Atomic Reference Counting, is a thread-safe reference-counting pointer for sharing data across multiple threads. Unlike Rc, which is not thread-safe, Arc is designed to work in concurrent environments, allowing multiple ownership of the same data without data races.

When to Use Arc

Use Arc when you need to share immutable data between threads. It is particularly useful when you want to clone references to data that needs to be accessed by multiple threads, as it handles the atomic reference counting for you, preventing data corruption.

Basic Usage of Arc

To use Arc, you simply wrap your data in an Arc, and clone it to share across threads. Here's a simple example demonstrating its usage:

Arc with Mutex

Arc can be combined with Mutex to enable safe mutable access to shared data. This is useful when you need to mutate data across threads. Here's an example:

Performance Considerations

While Arc provides a convenient way to share data, it comes with some overhead due to atomic operations. Consider using Arc only when necessary, such as when you need to share data between threads. For single-threaded scenarios, Rc is more efficient.

Conclusion

Arc is an essential tool in the Rust concurrency toolkit, offering a way to share data safely across threads. By combining Arc with other synchronization primitives like Mutex, you can achieve both shared ownership and mutable access in a thread-safe manner.