Remaining review follow-ups:
- killProcessTree now escalates to SIGKILL after 500ms if SIGTERM
doesn't kill the process (same pattern as killTrackedProcesses).
Covers orphan cleanup and dev/local mode tree kill.
- Added unit tests for both new modules:
- processTracker.test.ts (6 tests): track/remove on exit/error,
kill running processes, SIGKILL escalation for SIGTERM-resistant
processes, idempotency.
- orphanCleanup.test.ts (5 tests): tree kill with children,
SIGKILL escalation, non-existent PID handling, orphan detection
returns 0 when clean.
- Blocker: arm 3s force-exit timer BEFORE awaiting cleanup, not
inside .finally(). Prevents hang if drainBrowserPool() blocks on
dead Chrome.
- Reorder cleanup: killTrackedProcesses() (sync, fast) runs first,
then async browser drain. Ffmpeg dies immediately instead of
surviving if the hard timer fires early.
- SIGKILL escalation: processTracker now SIGTERMs all tracked
processes, then SIGKILLs survivors after 500ms grace period.
- Scope pgrep to current user (pgrep -u $(id -u)) so orphan
detection doesn't touch other users' Chrome on shared machines.
- Add process.on('exit') handler for crash paths (unhandled
exceptions/rejections that bypass signal handlers).
- Document Windows no-op behavior on killProcessTree handlers.
The preview command's shutdown handler only closed the HTTP server,
leaving Chrome (browser pool) and ffmpeg processes alive. This caused
silent resource leaks — orphaned processes consuming CPU and RAM with
no parent.
Root cause: preview.ts never called drainBrowserPool() or killed
tracked ffmpeg processes. The thumbnail browser in studioServer.ts
registered its own competing signal handlers that raced with
preview's shutdown.
Fix:
- Add a central process tracker (processTracker.ts) that registers
every spawned ffmpeg across engine and producer packages
- Centralize thumbnail browser cleanup via exported
closeThumbnailBrowser() instead of scattered signal handlers
- Wire preview shutdown to call closeThumbnailBrowser(),
drainBrowserPool(), and killTrackedProcesses() before closing the
HTTP server (embedded mode)
- Add killProcessTree() for dev/local modes where Chrome runs in a
child process tree
- Add startup orphan detection that finds and kills orphaned
chrome-headless-shell/Puppeteer Chrome processes (PPID=1) from
previously crashed sessions
Closes#1038
Miguel Ángel