Merge pull request #458 from rstudio/export-lock

Author: wch

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Other changes
 
+* `shiny.reactive.lock` is now exported. (#458)
 
 ## [0.3.2] - 2023-04-19
 

shiny/reactive/__init__.py

@@ -2,6 +2,7 @@
     isolate,
     invalidate_later,
     flush,
+    lock,
     on_flushed,
     get_current_context,  # pyright: ignore[reportUnusedImport]
 )
@@ -18,14 +19,15 @@
 
 
 __all__ = (
+    "isolate",
+    "invalidate_later",
     "flush",
+    "lock",
     "on_flushed",
+    "poll",
+    "file_reader",
     "Value",
     "Calc",
     "Effect",
     "event",
-    "isolate",
-    "invalidate_later",
-    "poll",
-    "file_reader",
 )

shiny/reactive/_core.py

@@ -2,7 +2,14 @@
 
 from __future__ import annotations
 
-__all__ = ("isolate", "invalidate_later", "flush", "on_flushed", "get_current_context")
+__all__ = (
+    "isolate",
+    "invalidate_later",
+    "flush",
+    "lock",
+    "on_flushed",
+    "get_current_context",
+)
 
 import asyncio
 import contextlib
@@ -279,7 +286,13 @@ def on_flushed(
 
 
 def lock() -> asyncio.Lock:
-    """A lock that should be held whenever manipulating the reactive graph."""
+    """
+    A lock that should be held whenever manipulating the reactive graph.
+
+    For example, this makes it safe to set a :class:`~reactive.Value` and call
+    :func:`~reactive.flush()` from a different :class:`~asyncio.Task` than the one that
+    is running the Shiny :class:`~shiny.Session`.
+    """
     return _reactive_environment.lock