fix: resolve high CPU usage from event subscription loop and aggressive polling#394
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Dimillian merged 2 commits intoDimillian:mainfrom Feb 10, 2026
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…ve polling - useAppServerEvents: stabilize subscription with useRef to prevent infinite subscribe/unsubscribe loop caused by handlers object recreation on every render - useWorkspaceFiles: reduce polling frequency (30s/60s instead of 5s/20s) and pause polling when tab is hidden Fixes Dimillian#393 Co-authored-by: Amp <amp@ampcode.com> Amp-Thread-ID: https://ampcode.com/threads/T-019c4703-2ce1-7308-9585-7f7c41730fbb
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Problem
Fixes #393
WebKit.WebContentprocess consumes 60-75% CPU and 1GB+ RAM, causing severe UI lag — especially when switching back to Codex Monitor from another app.Root Cause
Three React hooks had unstable
useEffectdependency arrays, causing infinite re-registration loops and flooding the IPC bridge / backend with requests:useAppServerEvents—[handlers]dependency recreated every render → infinite subscribe/unsubscribe cycle on the event bridge.useWorkspaceRefreshOnFocus—[workspaces, ...]dependency recreated every render → re-registered focus/visibility listeners every render, and fired a burst of workspace + thread list refreshes on every focus event with no debounce.useRemoteThreadRefreshOnFocus— Same pattern as above, adding another immediate refresh on focus.When switching back to the app, all three hooks fired simultaneously, hammering the backend.
Changes
useAppServerEvents.tsuseRefto track the latest handlers, allowing the subscription effect to use an empty dependency array ([]) and remain stable across renders.handlers.references inside the effect withcurrentHandlers.from the ref.useWorkspaceRefreshOnFocus.tsuseRef+ empty dependency array to prevent listener re-registration.useRemoteThreadRefreshOnFocus.tsuseRef+ empty dependency array stabilization.useWorkspaceFiles.tsdocument.visibilityState === "hidden"(tab not visible / app minimized).Results (local build v0.7.49)