Log failure to shutdown workers in pool cleanly

src/calibre/srv/loop.py

@@ -566,6 +566,8 @@ def shutdown(self):
         wait_till = time.time() + self.opts.shutdown_timeout
         for pool in (self.plugin_pool, self.pool):
             pool.stop(wait_till)
+            if pool.workers:
+                self.log.warn('Failed to shutdown %d workers in %s cleanly' % (len(pool.workers), pool.__class__.__name__))
 
 class EchoLine(Connection):  # {{{
 

src/calibre/srv/tests/loop.py

@@ -89,6 +89,7 @@ def test_workers(self):
             with self.assertRaises(socket.timeout):
                 conn.getresponse()
             self.ae(pool.busy, 1)
+            server.loop.log.filter_level = server.loop.log.ERROR
             server.loop.stop()
             server.join()
             self.ae(1, sum(int(w.is_alive()) for w in pool.workers))