Ensure we do not unlock document when on the wrong thread (#521)

lumen/pipeline.py

@@ -14,6 +14,7 @@
 import tqdm  # type: ignore
 
 from panel.io.document import unlocked
+from panel.io.state import state as pn_state
 from panel.viewable import Viewer
 from panel.widgets import Widget
 from typing_extensions import Literal
@@ -301,8 +302,12 @@ def _update_data(self, *events: param.parameterized.Event, force: bool = False):
         for f in self.filters+self.transforms+self.sql_transforms:
             f._sync_refs()
 
-        with unlocked():
-            self.data = self._compute_data()
+        new_data = self._compute_data()
+        if pn_state._unblocked(pn_state.curdoc):
+            with unlocked():
+                self.data = new_data
+        else:
+            self.data = new_data
         if state.config and state.config.on_update:
             pn.state.execute(partial(state.config.on_update, self))
         self._stale = False

lumen/util.py

@@ -7,7 +7,6 @@
 import sys
 import unicodedata
 
-from contextlib import contextmanager
 from functools import partial, wraps
 from logging import getLogger
 from subprocess import check_output
@@ -20,8 +19,7 @@
 from jinja2 import DebugUndefined, Environment, Undefined
 from packaging.version import Version
 from pandas.core.dtypes.dtypes import CategoricalDtype
-from panel import state
-from panel.io.document import unlocked
+from panel.io.state import state
 
 log = getLogger(__name__)
 
@@ -142,19 +140,19 @@ def _j_getshell(x):
 def _j_getheaders(x):
     if isinstance(x, Undefined):
         x = x._undefined_name
-    return pn.state.headers.get(x, '')
+    return state.headers.get(x, '')
 
 def _j_getcookies(x):
     if isinstance(x, Undefined):
         x = x._undefined_name
-    return pn.state.cookies.get(x, '')
+    return state.cookies.get(x, '')
 
 def _j_getoauth(x):
     if isinstance(x, Undefined):
         x = x._undefined_name
-    if pn.state.user_info is None:
+    if state.user_info is None:
         return ''
-    return pn.state.user_info.get(x, '')
+    return state.user_info.get(x, '')
 
 def expand_spec(pars, context={}, getenv=True, getshell=True, getheaders=True,
                 getcookies=True, getoauth=True):
@@ -308,14 +306,14 @@ def wrapper(*args, **kwargs):
             try:
                 return func(*args, **kwargs)
             except Exception as e:
-                from .state import state
-                if state.config and state.config.on_error:
-                    pn.state.execute(partial(state.config.on_error, e))
+                from .state import state as session_state
+                if session_state.config and session_state.config.on_error:
+                    state.execute(partial(state.config.on_error, e))
                 if pn.config.notifications:
                     log.error(
                         f"{func.__qualname__!r} raised {type(e).__name__}: {e}"
                     )
-                    pn.state.notifications.error(message.format(e=e))
+                    state.notifications.error(message.format(e=e))
                 else:
                     raise e
         return wrapper
@@ -325,28 +323,6 @@ def wrapper(*args, **kwargs):
 
     return decorator
 
-@contextmanager
-def immediate_dispatch(doc=None):
-    """
-    Utility to trigger immediate dispatch of events even when Document
-    events are currently on hold.
-    """
-    doc = doc or state.curdoc
-
-    # Skip if not in a server context
-    if not doc or not doc._session_context:
-        yield
-        return
-
-    old_events = doc.callbacks._held_events
-    hold = doc.callbacks._hold
-    doc.callbacks._held_events = []
-    doc.callbacks.unhold()
-    with unlocked():
-        yield
-    doc.callbacks._hold = hold
-    doc.callbacks._held_events = old_events
-
 def slugify(value, allow_unicode=False) -> str:
     """
     Convert to ASCII if 'allow_unicode' is False. Convert spaces or repeated

lumen/views/base.py

@@ -18,6 +18,7 @@
 
 from bokeh.models import NumeralTickFormatter  # type: ignore
 from packaging.version import Version
+from panel.io.document import immediate_dispatch
 from panel.pane.base import PaneBase
 from panel.pane.perspective import (
     THEMES as _PERSPECTIVE_THEMES, Plugin as _PerspectivePlugin,
@@ -35,8 +36,7 @@
 from ..transforms.base import Transform
 from ..transforms.sql import SQLTransform
 from ..util import (
-    VARIABLE_RE, catch_and_notify, immediate_dispatch, is_ref,
-    resolve_module_reference,
+    VARIABLE_RE, catch_and_notify, is_ref, resolve_module_reference,
 )
 from ..validation import ValidationError