[TheCoelacanth]

Exclusive ownership is only half of Rust's ownership story. The other half is borrows. Borrows actually fit very well with concurrency.

For example, if you have some data structure synchronized with a mutex, the mutex would be the owner of that data structure. Everything else would just get borrowed access to the data structure when it locks the mutex. Rust's borrow checker can make sure that you don't keep any references to that data structure after you have released the mutex so you can't access the data structure again without locking the mutex again. The mutex itself would need unsafe code, but everything using the mutex wouldn't.