---
phase: 03-lifecycle-management
plan: 02
subsystem: bot-lifecycle
tags: [asyncio, telegram, subprocess-management, idle-timeout, graceful-shutdown]

# Dependency graph
requires:
  - phase: 03-01
    provides: SessionIdleTimer class with reset/cancel and PID tracking in ClaudeSubprocess
provides:
  - Automatic session suspension after idle timeout
  - Transparent session resume with history preservation
  - Race-free suspend/resume via asyncio.Lock per session
  - Orphaned subprocess cleanup at bot startup
  - Graceful shutdown with subprocess termination
  - /timeout command for per-session idle configuration
  - /sessions command for session status overview
affects: [03-03-output-modes]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Race prevention via per-session asyncio.Lock for concurrent suspend/resume"
    - "Silent suspension (no Telegram notification) per CONTEXT.md decision"
    - "Resume detection via .claude/ directory existence check"
    - "Idle timer reset in on_complete callback (timer only counts after Claude finishes)"

key-files:
  created: []
  modified:
    - telegram/bot.py

key-decisions:
  - "Silent suspension (no Telegram notification) per CONTEXT.md LOCKED decision"
  - "Race prevention via subprocess_locks dict: one asyncio.Lock per session"
  - "Resume shows idle duration if >1 min (e.g., 'Resuming session (idle for 15 min)...')"
  - "Orphaned PID verification via /proc/cmdline check (only kill claude processes)"
  - "Bot shutdown uses post_shutdown callback (python-telegram-bot handles signals)"

patterns-established:
  - "Per-session locking: subprocess_locks.setdefault(session_name, asyncio.Lock())"
  - "Idle timer lifecycle: create on session spawn, reset in on_complete, cancel on archive"
  - "Resume status message format: 'Resuming session (idle for Xm)...'"

# Metrics
duration: 4min
completed: 2026-02-04
---

# Phase 3 Plan 2: Suspend/Resume Implementation Summary

**Automatic session suspension after 10min idle, transparent resume with full history, race-free with asyncio.Lock per session**

## Performance

- **Duration:** 4 min
- **Started:** 2026-02-04T23:33:30Z
- **Completed:** 2026-02-04T23:37:56Z
- **Tasks:** 2
- **Files modified:** 1

## Accomplishments
- Sessions automatically suspend after idle timeout (subprocess terminated, metadata updated, silent)
- User messages to suspended sessions transparently resume with full history
- Race condition between timeout-fire and user-message prevented via asyncio.Lock per session
- Bot startup kills orphaned subprocess PIDs (verified via /proc/cmdline)
- Bot shutdown terminates all subprocesses gracefully (SIGTERM + timeout + SIGKILL)
- /timeout command sets per-session idle timeout (1-120 min range)
- /sessions command lists all sessions with LIVE/IDLE status, persona, and relative last-active time

## Task Commits

Each task was committed atomically:

1. **Task 1: Suspend/resume wiring with race locks, startup cleanup, and graceful shutdown** - `6ebdb4a` (feat)
   - suspend_session() callback for idle timer
   - get_subprocess_lock() helper to prevent races
   - Resume logic in handle_message/handle_photo/handle_document
   - Idle timer reset in on_complete and on user activity
   - cleanup_orphaned_subprocesses() with /proc/cmdline verification
   - post_init() and post_shutdown() lifecycle callbacks
   - Updated new_session, switch_session_cmd, archive_session_cmd, model_cmd

2. **Task 2: /timeout and /sessions commands** - `06c5246` (feat)
   - timeout_cmd() to set/show per-session idle timeout
   - sessions_cmd() to list all sessions with status
   - Registered both commands in main()

## Files Created/Modified
- `telegram/bot.py` - Added suspend/resume lifecycle, idle timers, race locks, startup cleanup, graceful shutdown, /timeout and /sessions commands

## Decisions Made

**From plan execution:**
- Resume status message shows idle duration if >1 min: "Resuming session (idle for 15 min)..."
- Orphaned subprocess cleanup verifies PID is a claude process via /proc/cmdline before killing
- Bot shutdown uses post_shutdown callback (python-telegram-bot Application handles signal installation internally)

**Already documented in STATE.md:**
- Silent suspension (no Telegram notification) - from CONTEXT.md LOCKED decision
- Switching sessions leaves previous subprocess running (suspends on its own timer) - from CONTEXT.md LOCKED decision

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None

## Next Phase Readiness

**Ready for Phase 3 Plan 3 (Output Modes):**
- Session lifecycle fully implemented (suspend/resume, timeout configuration, status commands)
- Subprocess management robust (startup cleanup, graceful shutdown)
- Race conditions handled via per-session locks

**No blockers or concerns**

---
*Phase: 03-lifecycle-management*
*Completed: 2026-02-04*
