1 files changed, 21 insertions, 0 deletions
diff --git a/Lib/asyncio/mixins.py b/Lib/asyncio/mixins.py
new file mode 100644
index 0000000..dbc4b5f
--- /dev/null
+++ b/Lib/asyncio/mixins.py
@@ -0,0 +1,21 @@
+"""Event loop mixins."""
+
+import threading
+from . import events
+
+_global_lock = threading.Lock()
+
+
+class _LoopBoundedMixin:
+    _loop = None
+
+    def _get_loop(self):
+        loop = events._get_running_loop()
+
+        if self._loop is None:
+            with _global_lock:
+                if self._loop is None:
+                    self._loop = loop
+        if loop is not self._loop:
+            raise RuntimeError(f'{type(self).__name__} have already bounded to another loop')
+        return loop