Fix pipelined engine reset(): cancel before drain#47
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The producer task holds the engine lock until it finishes. If the consumer stops early (e.g. EOS detected), the producer may still be running. drain() waits for the lock to be released, but cancellation was only happening AFTER drain — creating a deadlock that triggers the 5-second fatalError timeout. Fix: cancel the GenerationToken and Task before calling drain(). The producer checks isCancelled on its next loop iteration, releases the lock, and drain() can proceed. Fixes apple#41
stikves
requested review from
alejandro-isaza,
carinapeng,
kevchengcodes and
tjia1818
tjia1818
approved these changes
Jun 15, 2026
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The producer task holds the engine lock until it finishes. If the consumer stops early (e.g. EOS detected), the producer may still be running. drain() waits for the lock to be released, but cancellation was only happening AFTER drain — creating a deadlock that triggers the 5-second fatalError timeout.
Fix: cancel the GenerationToken and Task before calling drain(). The producer checks isCancelled on its next loop iteration, releases the lock, and drain() can proceed.
Fixes #41