ALSAStream._read_loop just returned when arecord died or hit EOF, and
__exit__ never checked the exit status. SoundcardRecorder.record's inner
loop only slept and flushed, so nothing ever noticed: the recorder stayed
"running", kept rolling over to a new split file on schedule, and wrote
zero bytes into every one of them. The max_retries/reconnect path below
it was unreachable. Worst kind of failure for an unattended recorder —
files keep appearing, at the right times, with the right names.
ALSAStream now tracks when audio last arrived and exposes check_alive(),
which raises if the process exited or nothing has been captured for
SILENCE_TIMEOUT (15 s). The record loop calls it every 0.5 s tick, so a
dead device unwinds into the existing retry handler.
retry_count resets only when the stream actually delivered audio —
resetting on every healthy tick would let a device that opens but never
captures retry forever, which is the same silent failure by another
route.
Also: join the stderr thread in __exit__, and break _read_loop on EOF
rather than looping until poll() catches up.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
adminandClaude Opus 5