Test Pool(use_greenlets=True) when Gevent is not installed. PYTHON-561

test/test_pooling_gevent.py

@@ -14,16 +14,19 @@
 
 """Tests for connection-pooling with greenlets and Gevent"""
 
+import gc
+import time
 import unittest
 
 from nose.plugins.skip import SkipTest
 
 from pymongo import pool
+from pymongo.errors import ConfigurationError
 from test import host, port
 from test.utils import looplet
 from test.test_pooling_base import (
     _TestPooling, _TestMaxPoolSize, _TestMaxOpenSockets,
-    _TestPoolSocketSharing, _TestWaitQueueMultiple)
+    _TestPoolSocketSharing, _TestWaitQueueMultiple, has_gevent)
 
 
 class TestPoolingGevent(_TestPooling, unittest.TestCase):
@@ -189,5 +192,49 @@ class TestWaitQueueMultipleGevent(_TestWaitQueueMultiple, unittest.TestCase):
     use_greenlets = True
 
 
+class TestUseGreenletsWithoutGevent(unittest.TestCase):
+    def test_use_greenlets_without_gevent(self):
+        # Verify that Pool(use_greenlets=True) raises ConfigurationError if
+        # Gevent is not installed, and that its destructor runs without error.
+        if has_gevent:
+            raise SkipTest(
+                "Gevent is installed, can't test what happens calling "
+                "Pool(use_greenlets=True) when Gevent is unavailable")
+
+        # Possible outcomes of __del__.
+        DID_NOT_RUN, RAISED, SUCCESS = range(3)
+        outcome = [DID_NOT_RUN]
+
+        class TestPool(pool.Pool):
+            def __del__(self):
+                try:
+                    pool.Pool.__del__(self)  # Pool is old-style, no super()
+                    outcome[0] = SUCCESS
+                except:
+                    outcome[0] = RAISED
+
+        # Pool raises ConfigurationError, "The Gevent module is not available".
+        self.assertRaises(
+            ConfigurationError,
+            TestPool,
+            pair=(host, port),
+            max_size=10,
+            net_timeout=1000,
+            conn_timeout=1000,
+            use_ssl=False,
+            use_greenlets=True)
+
+        # Convince Jython or PyPy to call __del__.
+        for _ in range(10):
+            if outcome[0] == DID_NOT_RUN:
+                gc.collect()
+                time.sleep(0.1)
+
+        if outcome[0] == DID_NOT_RUN:
+            self.fail("Pool.__del__ didn't run")
+        elif outcome[0] == RAISED:
+            self.fail("Pool.__del__ raised exception")
+
+
 if __name__ == '__main__':
     unittest.main()