Add *Channel.is_closed().

Author: ericsnowcurrently

Lib/test/support/interpreters.py

@@ -165,6 +165,10 @@ def id(self):
     def _info(self):
         return _channels.get_info(self._id)
 
+    @property
+    def is_closed(self):
+        return self._info.closed
+
 
 _NOT_SET = object()
 
@@ -217,6 +221,11 @@ class SendChannel(_ChannelEnd):
 
     _end = 'send'
 
+    @property
+    def is_closed(self):
+        info = self._info
+        return info.closed or info.closing
+
     def send(self, obj, timeout=None):
         """Send the object (i.e. its data) to the channel's receiving end.