fix(moq-ffi): unblock deadlocking dynamic_track_request tests#1712
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dynamic_track_request and dynamic_track_request_can_abort awaited consumer.subscribe_track() to completion before reaching dynamic.requested_track() on the next line. For a not-yet-published (dynamic) track, subscribe_track().await stays pending until the producer accepts the request, which only happens once requested_track() runs. Single-task deadlock: the test could never reach the line that unblocks the line it was waiting on. Drive both sides concurrently with tokio::join! so the producer accepts the request while the consumer is still awaiting acceptance. The requested_track() side keeps its TIMEOUT wrapper so a real regression fails fast instead of hanging. This is pre-existing debt unrelated to moq-video: b1580b4 made subscribe_track async (correct, the pending-until-accepted contract is intentional) but the tests were never caught because moq-ffi's tests never ran in CI. `just rs ci` died at the NVENC compile before reaching the test phase until #1704 fixed that pipeline. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
kixelated
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June 13, 2026 21:46
kixelated
disabled auto-merge
June 13, 2026 22:05
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Summary
Two moq-ffi tests deadlocked (hung forever):
dynamic_track_requestanddynamic_track_request_can_abortinrs/moq-ffi/src/test.rs.Root cause: the tests called
consumer.subscribe_track("...").awaitbeforedynamic.requested_track()on the next line. For a not-yet-published (dynamic) track,subscribe_track().awaitstays pending until the producer accepts the request viarequested_track(). Butrequested_track()only runs on the line after the one the test is blocked on, so it's never reached. Classic single-task deadlock. The siblingmedia_track_activity_and_namedoesn't hang because it publishes the track first, sosubscribe_trackfinds an existing producer and returns immediately.The
awaititself is correct: the pending-until-accepted contract is intentional (see thesubscribe_pending!macro inrs/moq-net/src/model/broadcast.rs, which asserts subscribe stays pending until the request is accepted). The bug was the test driving the two sides sequentially.Fix
Drive the consumer subscribe and the producer
requested_track()concurrently withtokio::join!, so the producer accepts the request while the consumer is still awaiting acceptance. Therequested_track()side keeps its existingTIMEOUTwrapper, so a real regression fails fast instead of hanging.Why this was never caught
b1580b48madesubscribe_trackasync (correct) but moq-ffi's tests have never actually run in CI:just rs ci'scargo test --workspace --all-featuresdied at the NVENC compile (since #1691) before reaching the test phase. #1704 fixed that pipeline, so the tests now run — and hung. This is pre-existing moq-ffi debt, unrelated to the moq-video work.Test plan
nix develop --command cargo test -p moq-ffi— 20 passed, 0 failed (the two previously-hanging tests now finish in 0.42s total)nix develop --command cargo test --workspace --all-features --exclude moq-video— exit 0, whole suite green, no hang(Written by Claude)