zit serve accepts one connection to completion before the next (single-threaded, serve.zig), and receiveHead plus the body read blocked with no deadline. A loopback peer that dribbles a request head, half-sends a body, or connects idle and holds could pin the accept loop forever -- the socket read path the exchange fuzzers never reach, covered before only by happy-path interop.

Add a whole-connection deadline: the request work runs on its own unit of concurrency raced against a timed sleep, and draining the loser cancels the blocked read, freeing the loop. A per-read SO_RCVTIMEO is unusable here (the Io backend treats a socket-timeout EAGAIN as a bug). serve binds 127.0.0.1 only, so a legitimate same-host request finishes in milliseconds even at the 512 MiB body ceiling; the 5 s bound never fires on a real client and only sheds a stalled one.

Four end-to-end scenarios abuse a live server over loopback -- dribbled head, half-sent body, mid-response disconnect, idle-connection burst -- and assert with bounded waits that a fresh request is still answered and a clone still converges (sync 3.7). closed check-in: e87fb840d1 user: dmestas tags: h11-serve-socket