asyncio: Make run_forever() actually run forever.

asyncio/asyncio.py

@@ -39,13 +39,17 @@ class EventLoop:
         time.sleep(delay)
 
     def run_forever(self):
-        while self.q:
+        while True:
-#            t, cnt, cb, args = self.q.pop(0)
+            if self.q:
                 t, cnt, cb, args = heapq.heappop(self.q)
                 tnow = self.time()
                 delay = t - tnow
                 if delay > 0:
                     self.wait(delay)
+            else:
+                self.wait(-1)
+                # Assuming IO completion scheduled some tasks
+                continue
             if callable(cb):
                 cb(*args)
             else: