Priority inversions (Thread Performance Checker): the Apple client drains every
plane on .userInteractive threads (video pump, audio, gamepad feedback) and
connects on a .userInitiated Task, but the connector's producer threads ran at
the default QoS — so a high-QoS consumer parked waiting on a lower-QoS producer.
Pin the connector's producers (outer worker thread, all tokio runtime threads via
on_thread_start, and the data-plane spawn_blocking pump) to .userInteractive on
Apple so they match the consumers. #[cfg(target_vendor = "apple")] helper using
the existing libc dep; no-op off Apple, no Swift-side change (no latency
regression).
GamepadFeedback.swift: the init's MainActor hop captured self implicitly-strong
while the inner $active sink captured it weakly — capture [weak self] in the hop
too (the sink stays weak to avoid the retain cycle).
StreamPump.swift: the @Sendable pump-thread closure captured the non-Sendable
AVSampleBufferDisplayLayer. enqueue/flush are documented thread-safe and only the
pump thread drives it after start(), so assert that with nonisolated(unsafe).
cargo build/test/clippy/fmt green (core + host); xcframework rebuilt; swift build
+ iOS/tvOS targets clean with both warnings gone. Runtime confirmation of the
inversion warnings needs a GUI run under Xcode's Thread Performance Checker.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
157c7dbbb2