Only cancel channel spawned rpc tasks when explicitly notified

piker/tractor.py

@@ -234,6 +234,10 @@ class Actor:
         assert actorid, f"`actorid` can't be {actorid}"
         q = self.get_waitq(actorid, cid)
         log.debug(f"Delivering {msg} from {actorid} to caller {cid}")
+        waiters = q.statistics().tasks_waiting_get
+        if not waiters:
+            log.warn(
+                f"No tasks are currently waiting for results from call {cid}?")
         q.put_nowait(msg)
 
     def get_waitq(self, actorid, cid):
@@ -264,6 +268,8 @@ class Actor:
             try:
                 async for msg in chan.aiter_recv():
                     if msg is None:  # terminate sentinel
+                        log.debug(f"Cancelling all tasks for {chan}")
+                        nursery.cancel_scope.cancel()
                         log.debug(f"Terminating msg loop for {chan}")
                         break
                     log.debug(f"Received msg {msg}")
@@ -312,8 +318,6 @@ class Actor:
             except trio.ClosedStreamError:
                 log.error(f"{chan} broke")
 
-            log.debug(f"Cancelling all tasks for {chan}")
-            nursery.cancel_scope.cancel()
         log.debug(f"Exiting msg loop for {chan}")
 
     def _fork_main(self, accept_addr, parent_addr=None, loglevel=None):