After an unexpected exit the monitor thread returned on its own but
stayed joinable, and start() only spawned a monitor when none was
joinable. A node restarted after a crash (no stop() in between) then ran
unwatched: a second crash was never detected, its output was never
drained, and the dead run's stdout pipe leaked into the next fork.
- start() joins a monitor that returned on its own (only when joinable,
at the top, after the "already running" early returns), closes the
dead run's stdout pipe (Windows: process and pipe handles), and always
starts a new monitor for the process it launched. crash_count_ is kept.
- New lifecycle_mutex_ serializes start(), beginStop(), stop()'s flag
writes and joins, and endStop(), so two threads can never join the same
monitor. The monitor thread and the state callback never take it; a
beginStop() racing a start() waits for it to return (its longest wait
is the ~300 ms datadir-lock poll).
- start() is refused (returns false, state unchanged) while a stop is in
progress, i.e. between beginStop() and endStop().
- The daemon tests now start the stand-in only in isolation (temp
-datadir override, port check skipped): they no longer write the real
~/.hush/DRAGONX/obsidiandragon-dragonxd.pid or tail the real debug.log.
New tests: restart after a crash is supervised, a restarted run stops
cleanly, no fd leak over crash+restart cycles (Linux), and start() is
refused while stopping.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
DanSandClaude Opus 5.5
70d8b0f687