When a client has no connections, its read should not busy-wait

nsq/client.py

@@ -12,6 +12,7 @@
 import random
 from select import select
 import socket
+import time
 import threading
 
 
@@ -173,6 +174,9 @@ def read(self):
         connections = [c for c in self.connections() if c.alive()]
 
         if not connections:
+            # If there are no connections, obviously we return no messages, but
+            # we should wait the duration of the timeout
+            time.sleep(self._timeout)
             return []
 
         # Not all connections need to be written to, so we'll only concern

test/test_client.py

@@ -236,6 +236,14 @@ def test_read_with_no_connections(self):
         with mock.patch.object(self.client, 'connections', return_value=[]):
             self.assertEqual(self.client.read(), [])
 
+    def test_read_sleep_no_connections(self):
+        '''Sleeps for timeout if no connections'''
+        with mock.patch.object(self.client, '_timeout', 5):
+            with mock.patch.object(self.client, 'connections', return_value=[]):
+                with mock.patch('nsq.client.time.sleep') as mock_sleep:
+                    self.client.read()
+                    mock_sleep.assert_called_with(self.client._timeout)
+
     def test_random_connection(self):
         '''Yields a random client'''
         found = []