mpypy and docs fixups

tractor/_actor.py

@@ -303,11 +303,12 @@ class Actor:
 
     async def _push_result(
         self,
-        actorid: Tuple[str, str],
+        chan: Channel,
         msg: Dict[str, Any],
     ) -> None:
         """Push an RPC result to the local consumer's queue.
         """
+        actorid = chan.uid
         assert actorid, f"`actorid` can't be {actorid}"
         cid = msg['cid']
         send_chan = self._cids2qs[(actorid, cid)]
@@ -390,10 +391,10 @@ class Actor:
                                 f" {chan} from {chan.uid}")
                         break
 
-                    log.trace(f"Received msg {msg} from {chan.uid}")
+                    log.trace(f"Received msg {msg} from {chan.uid}")  # type: ignore
                     if msg.get('cid'):
                         # deliver response to local caller/waiter
-                        await self._push_result(chan.uid, msg)
+                        await self._push_result(chan, msg)
                         log.debug(
                             f"Waiting on next msg for {chan} from {chan.uid}")
                         continue

tractor/_portal.py

@@ -49,9 +49,10 @@ async def _do_handshake(
 
 
 class StreamReceiveChannel(trio.abc.ReceiveChannel):
-    """A wrapper around a ``trio.abc.ReceiveChannel`` with
+    """A wrapper around a ``trio._channel.MemoryReceiveChannel`` with
-    special behaviour for stream termination on both ends of
+    special behaviour for signalling stream termination on across an
-    an inter-actor channel.
+    inter-actor ``Channel``. This is the type returned to a local task
+    which invoked a remote streaming function using `Portal.run()`.
 
     Termination rules:
     - if the local task signals stop iteration a cancel signal is
@@ -65,7 +66,7 @@ class StreamReceiveChannel(trio.abc.ReceiveChannel):
         cid: str,
         rx_chan: trio.abc.ReceiveChannel,
         portal: 'Portal',
-    ):
+    ) -> None:
         self._cid = cid
         self._rx_chan = rx_chan
         self._portal = portal
@@ -84,28 +85,28 @@ class StreamReceiveChannel(trio.abc.ReceiveChannel):
             await self.aclose()
             raise StopAsyncIteration
         except trio.Cancelled:
+            # relay cancels to the remote task
             await self.aclose()
             raise
         except KeyError:
-            # if 'stop' in msg:
-            #     break  # far end async gen terminated
-            # else:
             # internal error should never get here
             assert msg.get('cid'), (
                 "Received internal error at portal?")
             raise unpack_error(msg, self._portal.channel)
 
     async def aclose(self):
+        """Cancel associate remote actor task on close
+        as well as the local memory channel.
+        """
         if self._rx_chan._closed:
             log.warning(f"{self} is already closed")
             return
         cid = self._cid
-        # XXX: cancel remote task on close
+        with trio.move_on_after(0.5) as cs:
+            cs.shield = True
             log.warning(
                 f"Cancelling stream {cid} to "
                 f"{self._portal.channel.uid}")
-        with trio.move_on_after(0.5) as cs:
-            cs.shield = True
             # TODO: yeah.. it'd be nice if this was just an
             # async func on the far end. Gotta figure out a
             # better way then implicitly feeding the ctx
@@ -117,6 +118,9 @@ class StreamReceiveChannel(trio.abc.ReceiveChannel):
                 pass
 
         if cs.cancelled_caught:
+            # XXX: there's no way to know if the remote task was indeed
+            # cancelled in the case where the connection is broken or
+            # some other network error occurred.
             if not self._portal.channel.connected():
                 log.warning(
                     "May have failed to cancel remote task "