The Standard Library as Architecture

• Arc gives endpoint and connection handles shared ownership independent of any one future.
• Mutex serializes each protocol state machine while allowing handles on many executor threads.
• AtomicUsize distinguishes public live handles from the driver itself.
• HashMap<StreamId, Waker> correlates readiness with exactly one blocked stream operation.
• Option<Waker> represents at most one driver notification claim.
• Pin<Box<dyn Future>> and trait objects erase runtime-specific timers and sockets at the narrow integration boundary.
• Bytes shares immutable packet/stream storage cheaply.
• enums preserve transport, application, reset, closed, 0-RTT, and local-close errors as separate states.

The types make the protocol’s ownership graph visible: socket → endpoint → connection → stream, with wake paths traveling back upward only when needed.