fix(exit): abort Xet downloads and stop LoRA staging at exit (#376)

Review follow-ups: Xet transfers report progress from native code and ignore
the chunk checkpoint, so the exit hook calls huggingface_hub's own
abort_xet_session when it is loaded; an aborted download logs as stopped.
LoRA import staging reads the exit signal itself, so the legacy LoRA scan
stops too. The test's fake encoder outlives the ceiling by less, and
TESTING.md states the download limits of older huggingface_hub.
This commit is contained in:
Vito Sansevero
2026-10-27 19:32:24 -07:00
parent 2c1e401d86
commit a8ab71eb1d
5 changed files with 124 additions and 14 deletions
+8 -3
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@@ -321,9 +321,14 @@ it sets the exit signal and kills the running encoder processes
(`shutdown_encoders`, the ffmpeg that never sees Ctrl+C on Windows). The call in
flight then stops at its next safe point: `Job.cancelled` is True, so every
check a job already makes between files stops it, `map_parallel` starts no
further item (`ExitRequested`), the scan walk stops between folders and a
tagging model download stops before its next chunk (huggingface_hub 1.x removes
its temp file). No check sits inside a library write. That hook is
further item (`ExitRequested`), the scan walk stops between folders, LoRA
import staging stops before its next sidecar (also for the legacy scan) and a
tagging model download stops before its next chunk where huggingface_hub takes
`tqdm_class` (1.x removes its temp file; 0.x `hf_hub_download` does not take it
and finishes the file). Xet transfers ignore that checkpoint, so the hook also
calls hub's own `abort_xet_session` when huggingface_hub is loaded. The
trigger-word cache load (small JSON sidecars) has no checkpoint. No check sits
inside a library write. That hook is
CPython-internal; without it (or when it is refused) `install` returns False and
exit waits for the call in flight, as before. `tests/test_exit_cancel.py` runs a
child process with three such calls running and requires its exit within 15 s.
+13
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@@ -364,12 +364,25 @@ def _kill_encoders_at_exit():
shutdown_encoders()
def _abort_downloads_at_exit():
"""Run by the exit hook (#376): huggingface_hub's Xet transfers ignore
the chunk checkpoint, so they are aborted the way hub aborts on Ctrl+C."""
import sys
if "huggingface_hub" not in sys.modules:
return # no download ever ran: import nothing at exit
from .py.autotag import abort_hub_downloads
abort_hub_downloads()
try:
# Before the executor join: running jobs stop at their next file, item or
# chunk (#376). The teardown below still runs from atexit afterwards.
from .utils import exit_signal as _exit_signal
_exit_signal.install(_kill_encoders_at_exit)
_exit_signal.install(_abort_downloads_at_exit)
except Exception as e:
try:
from .utils.logging_config import get_logger
+26 -5
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@@ -39,6 +39,25 @@ except ImportError:
from utils import exit_signal
def abort_hub_downloads() -> None:
"""Abort huggingface_hub's Xet transfers (run by the exit hook, #376).
Xet downloads report progress from native code, which ignores an
exception raised in ``tqdm.update``; huggingface_hub aborts them itself
on Ctrl+C with ``abort_xet_session``. Nothing happens when
huggingface_hub was never imported or has no Xet support.
"""
if "huggingface_hub" not in sys.modules:
return
try:
from huggingface_hub.utils import _xet
except ImportError:
return
abort = getattr(_xet, "abort_xet_session", None)
if callable(abort):
abort()
def _stop_at_exit(download) -> Dict[str, Any]:
"""Keyword arguments that stop a huggingface_hub download at its next
chunk once the interpreter is exiting (#376), or none when this
@@ -571,12 +590,14 @@ class AutoTagService:
return self._download_wd14_model(model_type, progress_callback)
else:
return self._download_hf_model(progress_callback)
except exit_signal.ExitRequested:
self.logger.info(
f"Model download stopped: ComfyUI is exiting ({model_type})"
)
return False
except Exception as e:
if exit_signal.requested():
# ExitRequested between chunks, or the Xet session aborted
# by the exit hook (abort_hub_downloads).
self.logger.info(
f"Model download stopped: ComfyUI is exiting ({model_type})"
)
return False
self.logger.error(f"Download failed: {e}")
if progress_callback:
progress_callback(f"Error: {str(e)}", 0)
+5 -2
View File
@@ -44,8 +44,10 @@ from .lora_manager_layout import (
)
try:
from ..utils import exit_signal
from ..utils.hashing import generate_prompt_hash
except ImportError: # pragma: no cover - flat test imports
from utils import exit_signal
from utils.hashing import generate_prompt_hash
LORA_CATEGORY = "lora-manager"
@@ -189,14 +191,15 @@ def stage(
downloads its CivitAI example images. A sidecar that cannot be read, or
whose record fails to build, is skipped by its name, as are the
centralized sidecars discovery could not parse. ``cancelled()`` is asked
before each sidecar (raises ImportCancelled); ``on_record(index,
before each sidecar, and so is the exit signal (#376: the legacy scan's
``cancelled`` does not read it); either raises ImportCancelled. ``on_record(index,
record_or_None, staged)`` follows each one.
"""
sidecars = discovery.sidecars
staged = StagedImport(total=len(sidecars))
staged.skipped.extend(discovery.unreadable)
for index, sidecar in enumerate(sidecars):
if cancelled():
if cancelled() or exit_signal.requested():
raise ImportCancelled()
record = None
path = sidecar.metadata_path
+72 -4
View File
@@ -41,6 +41,9 @@ CHILD_CEILING_SECONDS = 60
# at their next file, item or chunk (the encoder is killed).
EXIT_BOUND_SECONDS = 15
JOB_SECONDS = 600
# The fake encoder outlives the ceiling, yet a failing run leaks it only
# briefly (the parent cannot reach the child's own child to kill it).
ENCODER_SECONDS = 90
REPORT_PREFIX = "PM_EXIT_REPORT "
CHILD = textwrap.dedent("""
@@ -55,7 +58,8 @@ CHILD = textwrap.dedent("""
import threading
import time
root, tmp, job_seconds = sys.argv[1], sys.argv[2], float(sys.argv[3])
root, tmp = sys.argv[1], sys.argv[2]
job_seconds, encoder_seconds = float(sys.argv[3]), int(sys.argv[4])
sys.path.insert(0, root)
state = {"stopped": {}}
@@ -111,11 +115,11 @@ CHILD = textwrap.dedent("""
def encoder_work():
# Stands for ffmpeg on Windows, which runs without a console and
# never sees Ctrl+C: only a kill ends it before its timeout.
cmd = [sys.executable, "-c", "import time; time.sleep(%d)" % job_seconds]
cmd = [sys.executable, "-c", "import time; time.sleep(%d)" % encoder_seconds]
try:
encode.run_encoder(
cmd,
timeout=job_seconds,
timeout=encoder_seconds,
track=lambda _process: entered["encoder"].set(),
)
except Exception as error:
@@ -156,7 +160,14 @@ class TestExitStopsRunningWork(unittest.TestCase):
env["PYTHONIOENCODING"] = "utf-8"
try:
completed = subprocess.run(
[sys.executable, script, ROOT, tmp, str(JOB_SECONDS)],
[
sys.executable,
script,
ROOT,
tmp,
str(JOB_SECONDS),
str(ENCODER_SECONDS),
],
cwd=ROOT,
env=env,
capture_output=True,
@@ -298,6 +309,26 @@ class TestCheckpoints(_Isolated):
_collect_media_files([tmp], [".png"])
class TestLoraImportStopsAtExit(_Isolated):
def test_staging_stops_before_the_next_sidecar_whatever_the_caller_checks(self):
import types
from py import lora_import
discovery = types.SimpleNamespace(
sidecars=[object(), object()], unreadable=[], layout=None
)
exit_signal.request()
with tempfile.TemporaryDirectory() as tmp:
with self.assertRaises(lora_import.ImportCancelled):
lora_import.stage(
discovery,
tmp,
media_extensions=frozenset(),
cancelled=lambda: False, # the legacy scan's own check
)
class _FakeTqdm:
"""huggingface_hub.utils.tqdm as far as a download uses it."""
@@ -373,6 +404,43 @@ class TestModelDownloadStopsAtExit(_Isolated):
sorted(os.listdir(folder)), ["model.onnx", "selected_tags.csv"]
)
def test_xet_transfers_are_aborted_the_way_hub_aborts_on_ctrl_c(self):
import types
from py.autotag import abort_hub_downloads
aborted = []
xet = types.ModuleType("huggingface_hub.utils._xet")
xet.abort_xet_session = lambda: aborted.append(True)
hub = _fake_hub(chunks_before_exit=None)
hub["huggingface_hub.utils._xet"] = xet
hub["huggingface_hub.utils"]._xet = xet
with mock.patch.dict(sys.modules, hub):
abort_hub_downloads()
self.assertEqual(aborted, [True])
with mock.patch.dict(sys.modules):
sys.modules.pop("huggingface_hub", None)
abort_hub_downloads() # never imported: nothing to abort
self.assertEqual(aborted, [True])
def test_an_aborted_xet_download_is_logged_as_stopped(self):
from py.autotag import AutoTagService
hub = _fake_hub(chunks_before_exit=None)
def aborted(*args, **kwargs):
exit_signal.request() # the hook ran, then hub raised
raise RuntimeError("xet session aborted")
hub["huggingface_hub"].hf_hub_download = aborted
with tempfile.TemporaryDirectory() as tmp:
service = AutoTagService(models_dir=tmp)
with mock.patch.dict(sys.modules, hub):
with self.assertLogs(service.logger, "INFO") as logs:
self.assertFalse(service.download_model("wd14-vit"))
self.assertTrue(any("exiting" in line for line in logs.output), logs.output)
self.assertFalse(any("Download failed" in line for line in logs.output))
def test_an_old_hub_without_tqdm_class_downloads_as_before(self):
from py.autotag import AutoTagService