High CPU usage (70-90%) due to repeated TASK_LIST IPC calls

[carrgust]

Checklist

• I searched existing issues and this hasn't been reported

Area

Frontend

Operating System

macOS

Version

2.7.2 (develop branch, commit 230de5f)

What happened?

The Electron app uses 70-90% CPU when idle. Investigation shows repeated IPC calls between renderer and main process:

[IPC] TASK_LIST called with projectId: e57c7e91-dd6f-48b0-b33a-5dcd4965ca55
[ProjectStore] getTasks called with projectId: e57c7e91-dd6f-48b0-b33a-5dcd4965ca55
[ProjectStore] Found project: resumocast_portal autoBuildPath: .auto-claude
[ProjectStore] Loaded 20 tasks from main project
[ProjectStore] Loaded 3 tasks from worktree: 009-fix-unauthenticated-access...
[ProjectStore] Loaded 3 tasks from worktree: 010-sanitize-search-highlight...
... (11 worktrees with 3 tasks each)
[IPC] TASK_LIST returning 20 tasks
[IPC] PROJECT_LIST returning 2 projects
[IPC] TASK_LIST called with projectId: e57c7e91-dd6f-48b0-b33a-5dcd4965ca55
... (repeats continuously)

This appears to be a re-render loop in React that survived the fix in PR #362.

Related Issue

This is different from #231 (lsof spawning) - that issue is about backend task execution. This issue occurs when the app is idle with no tasks running.

Environment Details

• Project has 20 tasks in main project
• 11 git worktrees, each with 3 tasks
• 2 projects open in tabs

Steps to reproduce

1. Open a project with many tasks and worktrees
2. Keep the app idle (no tasks running)
3. Monitor CPU usage - stays at 70-90%
4. Check logs - repeated TASK_LIST and PROJECT_LIST calls

Expected behavior

CPU should be low (< 5%) when app is idle with no tasks running.

Suspected Cause

In App.tsx line 309-327, the useEffect that calls loadTasks() has these dependencies:

}, [activeProjectId, selectedProjectId, selectedProject?.path, selectedProject?.name]);

selectedProject is computed each render:

const selectedProject = projects.find((p) => p.id === (activeProjectId || selectedProjectId));

If the projects array reference changes, selectedProject becomes a new object, causing selectedProject?.path and selectedProject?.name to trigger the effect even when values haven't changed.

Possible Fix

1. Memoize selectedProject with useMemo
2. Or extract path and name before the dependency array comparison
3. Or use primitive values directly in dependencies instead of object properties

Logs / Screenshots

CPU usage while idle:

PID      CPU    Process
60952   72.2%  Electron Helper (GPU)
60955   13.8%  Electron Helper (Renderer)
60887    1.1%  Electron Main

🤖 Generated with Claude Code

[joelfuller2016]

@openhands-agent Please fix this high CPU usage issue caused by React re-render loop.

Issue Summary: Electron app uses 70-90% CPU when idle due to repeated IPC calls (TASK_LIST, PROJECT_LIST) in a re-render loop. This appears to be a React useEffect dependency issue.

Platform: macOS, v2.7.2 (develop branch, commit 230de5f)

Environment:

• 20 tasks in main project
• 11 git worktrees with 3 tasks each
• 2 projects open in tabs

CPU Usage Pattern:

PID      CPU    Process
60952   72.2%  Electron Helper (GPU)
60955   13.8%  Electron Helper (Renderer)
60887    1.1%  Electron Main

Root Cause Analysis (from reporter):

In App.tsx lines 309-327, the useEffect has these dependencies:

}, [activeProjectId, selectedProjectId, selectedProject?.path, selectedProject?.name]);

selectedProject is computed each render:

const selectedProject = projects.find((p) => p.id === (activeProjectId || selectedProjectId));

When projects array reference changes, selectedProject becomes a new object, triggering the effect even when values haven't changed.

Investigation Areas:

1. apps/frontend/src/App.tsx - Lines 309-327, the useEffect with loadTasks()
2. Check all useEffect dependencies involving computed objects
3. Look for similar patterns in other components

Required Fix:

1. Memoize selectedProject with useMemo
2. Or extract path and name before dependency comparison
3. Or use primitive values directly in dependencies
4. Verify fix doesn't break reactive updates

Example Fix:

const selectedProject = useMemo(
  () => projects.find((p) => p.id === (activeProjectId || selectedProjectId)),
  [projects, activeProjectId, selectedProjectId]
);

Target Branch: develop