Channels

Start with the idea

An mpsc channel moves values from many producers to one consumer, and the move is what makes it safe — once sent, the sender no longer owns the value. The receiver iterates until every sender is dropped, so the loop ends on its own rather than needing a sentinel message.

A channel separates the producer of a value from its consumer. In a multi-producer, single-consumer channel, several senders can submit messages to one receiver. Sending an owned String moves it into the channel; the sender cannot keep changing the same object afterward. That ownership transfer is a simple way to avoid sharing mutable state. If the sender needs its own copy too, make that duplication explicit.

The receiver loop can continue until every sender handle is dropped. A cloned sender counts as another live producer, even when it never sends anything.