Use trio memory channels throughout UIs

piker/ui/monitor.py

@@ -148,13 +148,14 @@ async def stream_symbol_selection():
     """
     widgets = tractor.current_actor().statespace['widgets']
     table = widgets['table']
-    q = trio.Queue(1)
-    table._click_queues.append(q)
+    send_chan, recv_chan = trio.open_memory_channel(0)
+    table._click_queues.append(send_chan)
     try:
-        async for symbol in q:
-            yield symbol
+        async with recv_chan:
+            async for symbol in recv_chan:
+                yield symbol
     finally:
-        table._click_queues.remove(q)
+        table._click_queues.remove(send_chan)
 
 
 async def _async_main(

piker/ui/tabular.py

@@ -383,8 +383,8 @@ class Row(HoverBehavior, GridLayout):
     def on_press(self, value=None):
         log.info(f"Pressed row for {self._last_record['symbol']}")
         if self.table and not self.is_header:
-            for q in self.table._click_queues:
-                q.put_nowait(self._last_record['symbol'])
+            for sendchan in self.table._click_queues:
+                sendchan.send_nowait(self._last_record['symbol'])
 
 
 class TickerTable(GridLayout):
@@ -399,7 +399,7 @@ class TickerTable(GridLayout):
         self._auto_sort = auto_sort
         self._symbols2index = {}
         self._sorted = []
-        self._click_queues: List[trio.Queue] = []
+        self._click_queues: List[trio.abc.SendChannel[str]] = []
 
     def append_row(self, key, row):
         """Append a `Row` of `Cell` objects to this table.