What is the difference between RwLock and Mutex?

Question

Accepted Answer

**RwLock** — multiple readers OR one writer. **Mutex** — exclusive access.

**RwLock:**
- Multiple readers.
- One writer.
- Read-heavy workloads.

**Mutex:**
- One owner.
- Simpler.
- Write-heavy.

```rust
use std::sync::{RwLock, Mutex};

// RwLock
let lock = RwLock::new(vec![]);
let r1 = lock.read().unwrap();
let r2 = lock.read().unwrap();  // Multiple readers OK
drop(r1);
drop(r2);
let mut w = lock.write().unwrap();

// Mutex
let lock = Mutex::new(vec![]);
let mut guard = lock.lock().unwrap();
guard.push(1);
```

**Key:** RwLock for reads, Mutex for writes.

Rust: What is the difference between RwLock and Mutex?