fix(exit): stop running jobs before Python joins the executor threads (#376)

ComfyUI returns from main.py after Ctrl+C without closing its event loop,
and Python joins every executor thread before any atexit callback runs, so
a scan batch, thumbnail batch or model download in flight kept ComfyUI
alive until it ended (on Windows each ffmpeg up to its 30 s timeout).

The package now registers a threading._register_atexit hook (after
concurrent.futures', so it runs before that join) that sets an exit signal
and kills the running encoder processes. Job.cancelled follows the signal,
so every check a job already makes between files stops it at exit;
map_parallel starts no further item, the scan walk stops between folders and
a tagging model download stops before its next chunk. Without the internal
hook exit behaves as before.

py/api/admin.py

@@ -34,6 +34,11 @@ try:
 except ImportError:
     from utils.parallel import map_parallel
 
+try:
+    from ...utils import exit_signal
+except ImportError:
+    from utils import exit_signal
+
 try:
     from ...database.pair_ingestion import blank_positive, ingest_resolved_pair
     from ...database.run_attribution import (
@@ -118,6 +123,7 @@ def _collect_media_files(output_dirs, extensions):
         if not os.path.isdir(root):
             continue
         for current, dirnames, filenames in os.walk(root, followlinks=False):
+            exit_signal.checkpoint()  # #376: stop between directories at exit
             depth = 0 if current == root else len(Path(current).relative_to(root).parts)
             dirnames[:] = sorted(
                 d

py/api/jobs.py

@@ -47,6 +47,11 @@ import time
 import uuid
 from pathlib import PurePosixPath, PureWindowsPath
 
+try:
+    from ...utils import exit_signal
+except ImportError:  # tests import the package top-level
+    from utils import exit_signal
+
 logger = logging.getLogger(__name__)
 # Start and finish order: wall-clock times can tie (coarse Windows clocks).
 _sequence = itertools.count()
@@ -195,11 +200,21 @@ class Job:
         self.counters = dict.fromkeys(groups, 0)
         self.outcomes = {group: [] for group in groups}
         self.log = []
-        self.cancelled = False
+        self._cancel_requested = False
         self.last_event = None
         self.task = None
         self._subscribers = set()
 
+    @property
+    def cancelled(self):
+        """Cancel was requested, or the interpreter is exiting (#376): every
+        check a job already makes between files also stops it at exit."""
+        return self._cancel_requested or exit_signal.requested()
+
+    @cancelled.setter
+    def cancelled(self, value):
+        self._cancel_requested = bool(value)
+
     @property
     def record_changing(self):
         return self.admission == "records"

py/api/thumbnail_auto.py

@@ -92,6 +92,11 @@ try:
 except ImportError:  # tests import the package top-level
     from utils.parallel import map_parallel
 
+try:
+    from ...utils.exit_signal import ExitRequested
+except ImportError:  # tests import the package top-level
+    from utils.exit_signal import ExitRequested
+
 # The placeholder frame a video without a preview is answered with (JPEG
 # bytes, never written to disk); written previews follow the settings.
 PLACEHOLDER_SIZE = (thumbnail_settings.DEFAULT_EDGE, thumbnail_settings.DEFAULT_EDGE)
@@ -448,6 +453,8 @@ class AutoThumbnailer:
     def _run(self):
         try:
             self._drain()
+        except ExitRequested:
+            pass  # #376: the interpreter is exiting; queued files are dropped
         except Exception:
             self._logger.warning("The automatic preview worker stopped", exc_info=True)
         finally:

py/autotag.py

@@ -7,6 +7,7 @@ Refactored from standalone_tagger.py for integration with PromptManager API.
 
 import errno
 import gc
+import inspect
 import os
 import sys
 from pathlib import Path
@@ -32,6 +33,35 @@ try:
 except ImportError:
     from py.tagging_defaults import DEFAULT_TAG_TEMPLATE
 
+try:
+    from ..utils import exit_signal
+except ImportError:
+    from utils import exit_signal
+
+
+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
+    huggingface_hub does not take ``tqdm_class``.
+
+    huggingface_hub 1.x removes its partial temp file on any failure; older
+    versions keep their resumable ``.incomplete`` file. The model's own path
+    is only written by the final rename either way.
+    """
+    try:
+        if "tqdm_class" not in inspect.signature(download).parameters:
+            return {}
+        from huggingface_hub.utils import tqdm as hub_tqdm
+    except (ImportError, TypeError, ValueError):
+        return {}
+
+    class StopAtExit(hub_tqdm):
+        def update(self, n=1):
+            exit_signal.checkpoint()
+            return super().update(n)
+
+    return {"tqdm_class": StopAtExit}
+
 
 def _autotag_config():
     """The saved defaults; imported late, as config needs ComfyUI's server."""
@@ -397,6 +427,7 @@ class AutoTagService:
                     filename=filename,
                     local_dir=str(model_dir),
                     local_dir_use_symlinks=False,
+                    **_stop_at_exit(hf_hub_download),
                 )
 
         if progress_callback:
@@ -540,6 +571,11 @@ 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:
             self.logger.error(f"Download failed: {e}")
             if progress_callback:
@@ -570,6 +606,7 @@ class AutoTagService:
                 filename=config["filename"],
                 local_dir=str(gguf_dir),
                 local_dir_use_symlinks=False,
+                **_stop_at_exit(hf_hub_download),
             )
             self.logger.info("GGUF model downloaded")
 
@@ -587,6 +624,7 @@ class AutoTagService:
                 filename=config["mmproj_filename"],
                 local_dir=str(gguf_dir),
                 local_dir_use_symlinks=False,
+                **_stop_at_exit(hf_hub_download),
             )
             self.logger.info("mmproj downloaded")
 
@@ -613,6 +651,7 @@ class AutoTagService:
                 repo_id=config["repo"],
                 local_dir=str(model_dir),
                 local_dir_use_symlinks=False,
+                **_stop_at_exit(snapshot_download),
             )
             self.logger.info("HF model downloaded")