perf: cut idle CPU from leaked watchers and unconditional polling - #35
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The main process pegged ~53% CPU continuously while idle. Three causes: - main.js: each subagent live-tail watcher used fs.watchFile, which stat-polls the file once per second per watcher, forever. Teardown via fs.unwatchFile(path) was fragile and watchers could accumulate across a long app session. Switch to event-driven fs.watch + 300ms debounce, and store a per-watcher teardown() closure called from both stop-subagent-watch and the window-closed handler so nothing leaks. Falls back to a 10s poll only if fs.watch fails to attach. - public/app.js: pollActiveSessions ran every 3s unconditionally (IPC + full-sidebar querySelectorAll) even with zero running sessions. Poll adaptively: 3s while sessions run, 30s when idle. In-renderer session starts re-arm the fast cadence immediately; the 30s floor still catches externally-started sessions. The 30s timeago interval now no-ops when nothing is active. - schedule-runner.js: scanSchedules re-read 4KB of every project JSONL every 60s just to extract projectPath. Resolve it from the cache_meta SQLite cache (getAllFolderMeta) instead, falling back to the JSONL read only when a folder is genuinely uncached. Lint clean; existing 119-test suite passes unchanged.
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Problem
The main process consumed ~53% CPU continuously while idle (observed after a 5h+ session), with renderer processes adding ~33%/~25%.
Root causes & fixes
1.
main.js—fs.watchFilestat-polling + watcher leak (main fix)Each subagent live-tail watcher used
fs.watchFile, which stat-polls the file once per second, per watcher, for the lifetime of the process. Teardown viafs.unwatchFile(path)was fragile and watchers could accumulate across a long session.fs.watch+ 300ms debounce (mirrors the existing projects watcher)teardown()closure called from bothstop-subagent-watchand the window-closed handler — watchers can no longer leakfs.watchfails to attach2.
public/app.js— unconditional 3s pollingpollActiveSessionsran every 3s (IPC + full-sidebarquerySelectorAll) even with zero running sessions.3.
schedule-runner.js— re-reading all JSONLs every 60sscanSchedulesread 4KB of every project JSONL every minute just to extractprojectPath.cache_metaSQLite cache (getAllFolderMeta), falling back to the JSONL read only when a folder is genuinely uncachedTesting
eslintclean (no new errors)node --testsuite: 119 pass / 0 fail, unchanged