fix(tui): prevent post-interrupt hang when ACP suppresses stale Completed#418
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fix(tui): prevent post-interrupt hang when ACP suppresses stale Completed#418
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…nterrupt hang When a user interrupts (Escape) and then submits a new message, the TUI hangs forever with the spinner running indefinitely. The ACP backend suppresses stale Completed events via the turn_interrupted flag, but the TUI's on_interrupted_turn increments pending_stale_completes expecting to consume that event. Since the backend suppresses it, the counter is never drained, and the next real Completed is consumed as stale. Reset the counter to 0 in on_task_started so orphaned counters from backend-suppressed events don't block subsequent turns. 🤖 Generated with [Nori](https://noriagentic.com) Co-Authored-By: Nori <contact@tilework.tech>
theahura
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The previous approach used a shared AtomicBool flag to suppress stale TurnLifecycle::Completed events from cancelled tasks. This had an unavoidable TOCTOU race: when a user interrupted and quickly sent a new message, the flag was reset for the new turn before the old task could check it, allowing stale events to interfere with subsequent turns. Two prior attempts (PRs #416, #418) tried to fix this with variations of the same boolean+counter architecture. Each fix introduced a new bug: #416 caused hangs, #418 brought back hidden responses. This commit replaces the architecture entirely: - AtomicBool → AtomicU64 monotonic turn counter in ACP backend - Each spawned task captures its own turn ID at spawn time - ALL tail events (ErrorEvent + Completed + idle timer) are guarded by a single turn_id match check - TUI's pending_stale_completes counter is removed (no longer needed) The monotonic counter eliminates the race because it only increments— there is no "reset" that a stale task can observe. 🤖 Generated with [Nori](https://noriagentic.com) Co-Authored-By: Nori <contact@tilework.tech>
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theahura
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Apr 6, 2026
The previous approach used a shared AtomicBool flag to suppress stale TurnLifecycle::Completed events from cancelled tasks. This had an unavoidable TOCTOU race: when a user interrupted and quickly sent a new message, the flag was reset for the new turn before the old task could check it, allowing stale events to interfere with subsequent turns. Two prior attempts (PRs #416, #418) tried to fix this with variations of the same boolean+counter architecture. Each fix introduced a new bug: #416 caused hangs, #418 brought back hidden responses. This commit replaces the architecture entirely: - AtomicBool → AtomicU64 monotonic turn counter in ACP backend - Each spawned task captures its own turn ID at spawn time - ALL tail events (ErrorEvent + Completed + idle timer) are guarded by a single turn_id match check - TUI's pending_stale_completes counter is removed (no longer needed) The monotonic counter eliminates the race because it only increments— there is no "reset" that a stale task can observe. 🤖 Generated with [Nori](https://noriagentic.com) Co-Authored-By: Nori <contact@tilework.tech>
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Summary
🤖 Generated with Nori
turn_interruptedflag (suppresses staleCompleted) and TUI'spending_stale_completescounter (expects to consume it). The counter was never drained, so the next realCompletedwas consumed as stale.pending_stale_completes = 0inon_task_startedso orphaned counters from backend-suppressed events don't block subsequent turnsTest Plan
just fixandjust fmtcleanShare Nori with your team: https://www.npmjs.com/package/nori-skillsets