Rust: What is the difference between channel::bounded and channel::unbounded?

bounded — backpressure. unbounded — no backpressure.

bounded:

• Fixed capacity.
• Backpressure.
• Memory bounded.

unbounded:

• No capacity limit.
• No backpressure.
• Memory unbounded.

1use tokio::sync::mpsc;
2
3// Bounded: blocks when full
4let (tx, rx) = mpsc::channel(32);
5
6// Unbounded: never blocks
7let (tx, rx) = mpsc::unbounded_channel();

Key: bounded for backpressure, unbounded for flexibility.