Files
bambuddy/backend/tests/unit/test_capture_pid_tracking.py
maziggy ef37ffa7c7 fix(obico): exclude snapshot capture PIDs from stream cleanup (#172)
The periodic camera cleanup task scans /proc for ffmpeg processes and
  kills any not in the active-streams registry. The Obico detection
  service's capture_camera_frame_bytes() spawns short-lived ffmpeg for
  snapshots but never registered the PID — so cleanup killed it as
  "orphaned" mid-capture (SIGKILL, exit -9), producing false errors and
  missed detection frames.

  Track capture PIDs in _active_capture_pids and exclude them from the
  cleanup kill list.
2026-04-17 08:38:22 +02:00

205 lines
8.1 KiB
Python

"""Tests for capture PID tracking and cleanup exclusion (#172).
The Obico detection service spawns short-lived ffmpeg processes for snapshot
capture via capture_camera_frame_bytes(). These must be registered in
_active_capture_pids so the cleanup task in routes/camera.py does not kill
them as orphaned.
"""
import asyncio
from unittest.mock import AsyncMock, MagicMock, patch
import pytest
from backend.app.services.camera import (
_active_capture_pids,
capture_camera_frame_bytes,
)
@pytest.fixture(autouse=True)
def _clear_capture_pids():
"""Ensure _active_capture_pids is empty before/after each test."""
_active_capture_pids.clear()
yield
_active_capture_pids.clear()
class TestCapturePidRegistration:
"""Verify PIDs are added/removed from _active_capture_pids."""
@pytest.mark.asyncio
async def test_pid_registered_during_capture(self):
"""PID is in _active_capture_pids while ffmpeg is running."""
observed_pids_during_run: set[int] = set()
fake_process = MagicMock()
fake_process.pid = 99999
fake_process.returncode = 0
async def fake_communicate():
# Snapshot what's in the set while "ffmpeg is running"
observed_pids_during_run.update(_active_capture_pids)
return (b"\xff\xd8" + b"\x00" * 200 + b"\xff\xd9", b"")
fake_process.communicate = fake_communicate
fake_proxy_server = AsyncMock()
fake_proxy_server.close = MagicMock()
with (
patch("backend.app.services.camera.is_chamber_image_model", return_value=False),
patch("backend.app.services.camera.get_camera_port", return_value=322),
patch("backend.app.services.camera.create_tls_proxy", return_value=(12345, fake_proxy_server)),
patch("backend.app.services.camera.get_ffmpeg_path", return_value="/usr/bin/ffmpeg"),
patch("asyncio.create_subprocess_exec", return_value=fake_process),
):
result = await capture_camera_frame_bytes("192.168.1.1", "test", "P2S", timeout=10)
# PID was registered during capture
assert 99999 in observed_pids_during_run
# PID is removed after capture completes
assert 99999 not in _active_capture_pids
# Capture returned data
assert result is not None
@pytest.mark.asyncio
async def test_pid_removed_after_failure(self):
"""PID is cleaned up even when ffmpeg returns non-zero."""
fake_process = MagicMock()
fake_process.pid = 88888
fake_process.returncode = 1
async def fake_communicate():
return (b"", b"some error")
fake_process.communicate = fake_communicate
fake_proxy_server = AsyncMock()
fake_proxy_server.close = MagicMock()
with (
patch("backend.app.services.camera.is_chamber_image_model", return_value=False),
patch("backend.app.services.camera.get_camera_port", return_value=322),
patch("backend.app.services.camera.create_tls_proxy", return_value=(12345, fake_proxy_server)),
patch("backend.app.services.camera.get_ffmpeg_path", return_value="/usr/bin/ffmpeg"),
patch("asyncio.create_subprocess_exec", return_value=fake_process),
):
result = await capture_camera_frame_bytes("192.168.1.1", "test", "P2S", timeout=10)
assert result is None
assert 88888 not in _active_capture_pids
@pytest.mark.asyncio
async def test_pid_removed_after_timeout(self):
"""PID is cleaned up when ffmpeg times out."""
fake_process = MagicMock()
fake_process.pid = 77777
fake_process.returncode = None
fake_process.kill = MagicMock()
async def fake_communicate():
await asyncio.sleep(60) # Will be cancelled by wait_for
return (b"", b"")
fake_process.communicate = fake_communicate
async def fake_wait():
fake_process.returncode = -9
fake_process.wait = fake_wait
fake_proxy_server = AsyncMock()
fake_proxy_server.close = MagicMock()
with (
patch("backend.app.services.camera.is_chamber_image_model", return_value=False),
patch("backend.app.services.camera.get_camera_port", return_value=322),
patch("backend.app.services.camera.create_tls_proxy", return_value=(12345, fake_proxy_server)),
patch("backend.app.services.camera.get_ffmpeg_path", return_value="/usr/bin/ffmpeg"),
patch("asyncio.create_subprocess_exec", return_value=fake_process),
):
result = await capture_camera_frame_bytes("192.168.1.1", "test", "P2S", timeout=0.01)
assert result is None
assert 77777 not in _active_capture_pids
@pytest.mark.asyncio
async def test_no_pid_tracked_for_chamber_image_models(self):
"""Chamber image models (A1/P1) don't spawn ffmpeg — no PID tracking."""
with (
patch("backend.app.services.camera.is_chamber_image_model", return_value=True),
patch("backend.app.services.camera.read_chamber_image_frame", return_value=b"\xff\xd8test\xff\xd9"),
):
result = await capture_camera_frame_bytes("192.168.1.1", "test", "A1", timeout=10)
assert result is not None
assert len(_active_capture_pids) == 0
@pytest.mark.asyncio
async def test_no_pid_tracked_when_subprocess_fails(self):
"""If create_subprocess_exec raises, process is None — no PID to track."""
fake_proxy_server = AsyncMock()
fake_proxy_server.close = MagicMock()
with (
patch("backend.app.services.camera.is_chamber_image_model", return_value=False),
patch("backend.app.services.camera.get_camera_port", return_value=322),
patch("backend.app.services.camera.create_tls_proxy", return_value=(12345, fake_proxy_server)),
patch("backend.app.services.camera.get_ffmpeg_path", return_value="/usr/bin/ffmpeg"),
patch("asyncio.create_subprocess_exec", side_effect=FileNotFoundError("ffmpeg")),
):
result = await capture_camera_frame_bytes("192.168.1.1", "test", "P2S", timeout=10)
assert result is None
assert len(_active_capture_pids) == 0
class TestCleanupExcludesCapturePids:
"""Verify cleanup_orphaned_streams skips PIDs in _active_capture_pids."""
@pytest.mark.asyncio
async def test_cleanup_skips_capture_pids(self):
"""A PID in _active_capture_pids must not be killed by cleanup."""
from backend.app.api.routes.camera import cleanup_orphaned_streams
_active_capture_pids.add(42000)
with (
patch("backend.app.api.routes.camera._scan_bambu_ffmpeg_pids", return_value=[42000]),
patch("backend.app.api.routes.camera._active_streams", {}),
patch("backend.app.api.routes.camera._spawned_ffmpeg_pids", {}),
patch("os.kill") as mock_kill,
):
await cleanup_orphaned_streams()
# os.kill should NOT have been called with SIGKILL for our capture PID
for call in mock_kill.call_args_list:
pid, sig = call[0]
assert pid != 42000, "cleanup killed an active capture PID"
@pytest.mark.asyncio
async def test_cleanup_kills_non_capture_pids(self):
"""PIDs NOT in _active_capture_pids should still be killed."""
import signal
from backend.app.api.routes.camera import cleanup_orphaned_streams
# 42000 is a capture PID, 43000 is truly orphaned
_active_capture_pids.add(42000)
with (
patch("backend.app.api.routes.camera._scan_bambu_ffmpeg_pids", return_value=[42000, 43000]),
patch("backend.app.api.routes.camera._active_streams", {}),
patch("backend.app.api.routes.camera._spawned_ffmpeg_pids", {}),
patch("os.kill") as mock_kill,
):
await cleanup_orphaned_streams()
# 43000 should have been killed
mock_kill.assert_any_call(43000, signal.SIGKILL)
# 42000 should NOT have been killed with SIGKILL
killed_pids = [call[0][0] for call in mock_kill.call_args_list if call[0][1] == signal.SIGKILL]
assert 42000 not in killed_pids