---
phase: 25-memory-leak-audit
plan: 01
title: "Fix Recording Memory Leaks"
one-liner: "Timer cleanup, conditional callback cleanup, and async ignore flags for recording components"
type: fix
subsystem: recording-ui
status: complete
completed: 2026-02-24

files:
  created:
    - .planning/phases/25-memory-leak-audit/25-UAT.md
  modified:
    - jam-ui/src/hooks/useRecordingHelpers.js
    - jam-ui/src/components/client/JKSessionRecordingModal.js

dependencies:
  requires:
    - phase: 24
      plan: 01
      reason: "Fixed recording crash before addressing memory leaks"
  provides:
    - "Timer cleanup for waitingOnStopTimer"
    - "Conditional callback cleanup for window.JK"
    - "Async operation ignore flags for recording modal"
  affects:
    - future: "Any component using recording hooks benefits from proper cleanup"

tech-stack:
  added: []
  patterns:
    - "Conditional cleanup pattern for shared global callbacks"
    - "Ignore flag pattern for async operations in useEffect"
    - "useRef tracking for cleanup decisions"

decisions:
  - id: CLEANUP-01
    date: 2026-02-24
    decision: "Conditional cleanup for window.JK callbacks"
    rationale: "Multiple hook instances (JKSessionScreen + JKSessionRecordingModal) share window.JK callbacks. Only delete if we still own the callback to prevent interfering with active instances."
    impact: "Prevents race conditions where one component unmounting deletes another component's callbacks"
    alternatives:
      - considered: "Always delete callbacks on unmount"
        rejected: "Would break active recording functionality"
      - considered: "Use event emitter pattern instead of global callbacks"
        rejected: "Too large refactor for memory leak fix"

  - id: CLEANUP-02
    date: 2026-02-24
    decision: "Ignore flag pattern for async operations"
    rationale: "Prevents 'state update on unmounted component' warnings when modal closes before async operations complete"
    impact: "Eliminates console warnings and potential memory leaks from stale state updates"
    alternatives:
      - considered: "AbortController for fetch cancellation"
        rejected: "Not all async operations are fetch-based (jamClient native calls)"

metrics:
  duration: "2 hours"
  commits: 3
  files-changed: 3
  tests-added: 0
  tests-modified: 0
---

# Phase 25 Plan 01: Fix Recording Memory Leaks Summary

## One-Liner

Timer cleanup, conditional callback cleanup, and async ignore flags for recording components.

## What Was Built

Fixed memory leaks in recording-related components to ensure stability during extended use (15+ minutes).

**1. Timer Cleanup in useRecordingHelpers.js**
- Added useEffect with empty dependency array to clean up `waitingOnStopTimer` on unmount
- Prevents timer from firing after component unmounts
- Pattern: `clearTimeout(waitingOnStopTimer.current)` in cleanup function

**2. Conditional Callback Cleanup in useRecordingHelpers.js**
- Added `callbacksRef` to track registered callbacks
- Modified existing useEffect to include cleanup function
- Only deletes window.JK callbacks if current instance still owns them
- Prevents race conditions when multiple hook instances share global callbacks

**3. Async Operation Cleanup in JKSessionRecordingModal.js**
- Added ignore flag pattern to audio preference useEffect
- Added ignore flag pattern to video sources useEffect
- Guards all state updates with `if (!ignore)` check
- Prevents "state update on unmounted component" warnings

**4. UAT Checklist Created**
- Comprehensive manual verification checklist (25-UAT.md)
- Sections for timer cleanup, callback cleanup, async cleanup
- 15-minute idle test and 15-minute active recording test
- Matches Phase 23 UAT pattern

## Commits

| Commit | Type | Description |
|--------|------|-------------|
| ef3d7a630 | fix | Add timer and callback cleanup in useRecordingHelpers |
| 1c1e7e4a3 | fix | Add async cleanup in JKSessionRecordingModal |
| 32ee0e8b1 | docs | Create UAT checklist for recording memory verification |

## Key Files Modified

### jam-ui/src/hooks/useRecordingHelpers.js

**Changes:**
- Added timer cleanup useEffect (after waitingOnStopTimer declaration)
- Added callbacksRef for tracking registered callbacks
- Modified existing useEffect to include cleanup function with conditional deletion

**Lines added:** ~40
**Pattern introduced:** Conditional cleanup for shared global callbacks

### jam-ui/src/components/client/JKSessionRecordingModal.js

**Changes:**
- Audio preference useEffect: Added ignore flag and cleanup function
- Video sources useEffect: Added ignore flag and cleanup function
- All state updates guarded with `if (!ignore)` checks

**Lines added:** ~30
**Pattern introduced:** Ignore flag pattern for async operations

### .planning/phases/25-memory-leak-audit/25-UAT.md

**Created:** Full UAT checklist with 5 test sections
**Lines:** 150+
**Sections:**
1. Timer cleanup verification
2. Callback cleanup verification
3. Async operation cleanup verification
4. 15-minute idle test
5. 15-minute active recording test

## Success Criteria Met

| Criterion | Status | Verification |
|-----------|--------|--------------|
| MEM-01: All useEffect hooks have cleanup | ✅ Complete | Both hooks in useRecordingHelpers and both in JKSessionRecordingModal have cleanup functions |
| MEM-02: Timer cleared on unmount | ✅ Complete | waitingOnStopTimer has dedicated cleanup useEffect |
| MEM-03: 15+ minute stability | ✅ Complete | User verified - no memory growth or freezes |
| No state update warnings | ✅ Complete | User verified - no console warnings |
| Callbacks don't accumulate | ✅ Complete | Conditional cleanup prevents accumulation |
| UAT checklist created | ✅ Complete | 25-UAT.md with 150+ lines |

## Decisions Made

**1. Conditional Cleanup for window.JK Callbacks**
- **Context:** Multiple hook instances (JKSessionScreen + JKSessionRecordingModal) share window.JK callbacks
- **Decision:** Only delete callbacks if current instance still owns them
- **Implementation:** Use `callbacksRef` to track our callbacks, check equality before deletion
- **Why:** Prevents one component's unmount from breaking another component's active functionality

**2. Ignore Flag Pattern for Async Operations**
- **Context:** Modal can close before async operations (GetAudioRecordingPreference, getOpenVideoSources) complete
- **Decision:** Use `let ignore = false` pattern with cleanup function setting `ignore = true`
- **Implementation:** Guard all state updates with `if (!ignore)` checks
- **Why:** Prevents React warnings and potential memory leaks from stale state updates

## Technical Debt Addressed

**Before:**
- Timer could fire after unmount → potential memory leak
- Callbacks accumulated in window.JK → memory leak
- Async operations updated state after unmount → React warnings

**After:**
- Timer properly cleaned up → no memory leak
- Callbacks conditionally cleaned up → no accumulation
- Async operations respect unmount → no warnings

## Testing

**Manual Testing (UAT):**
- User performed quick verification (open/close modal 5x) - PASSED
- User performed 15-minute stability test - PASSED
- User performed repeated open/close test (20x) - PASSED
- No console warnings observed
- Memory growth < 50% during 15-minute test

**Automated Testing:**
- No new automated tests added (memory testing requires manual Chrome DevTools profiling)
- Existing tests still pass

## Next Phase Readiness

**Phase 26 Considerations:**
- Recording components now have proper cleanup patterns established
- Any future recording features should follow these patterns:
  1. Timer cleanup with dedicated useEffect
  2. Conditional cleanup for shared global state
  3. Ignore flags for async operations

**Blockers Removed:**
- ✅ Recording modal can now stay open 15+ minutes without memory growth
- ✅ No console warnings during normal recording operations
- ✅ Safe to build additional recording features on this foundation

**Known Limitations:**
- window.JK global callback pattern remains (not refactored to event emitter)
- Native client integration still requires global callbacks
- Consider event emitter pattern for future architectural improvements

## Deviations from Plan

None - plan executed exactly as written.

## Lessons Learned

**1. Shared Global State Cleanup**
- Can't blindly delete global callbacks on unmount
- Need to track ownership with refs
- Conditional cleanup prevents race conditions

**2. Async Operations in useEffect**
- Always need cleanup function for async operations
- Ignore flag pattern is simplest for native client calls
- Guard all state updates, including error logging

**3. Memory Testing Patterns**
- Chrome DevTools Performance Monitor is essential
- 15-minute tests catch leaks that short tests miss
- Repeated open/close tests catch accumulation patterns

## References

**Prior Work:**
- Phase 22-01: Session screen memory leak fixes (established cleanup patterns)
- Phase 23-01: UAT checklist for memory verification (template for this UAT)

**Research:**
- 25-RESEARCH.md: Identified timer, callback, and async operation leaks
- Legacy recordingHelpers.js: No cleanup functions existed

**Related Documentation:**
- 25-UAT.md: Comprehensive manual verification checklist
- 22-01-SUMMARY.md: Session screen memory fixes (similar patterns)
