Add the concept of 'tracked_events' to CoroutinePool and CoroutinePool.wait, the method you use to drain the events

eventlet/coros.py

@@ -260,8 +260,13 @@ class CoroutinePool(pools.Pool):
     foo 4
     """
     
-    def __init__(self, min_size=0, max_size=4):
+    def __init__(self, min_size=0, max_size=4, track_events=False):
         self._greenlets = set()
+        if track_events:
+            self._tracked_events = []
+            self._next_event = None
+        else:
+            self._tracked_events = None
         super(CoroutinePool, self).__init__(min_size, max_size)
     
     def _main_loop(self, sender):
@@ -286,6 +291,13 @@ class CoroutinePool(pools.Pool):
             result = func(*args, **kw)
             if evt is not None:
                 evt.send(result)
+                if self._tracked_events is not None:
+                    if self._next_event is None:
+                        self._tracked_events.append(result)
+                    else:
+                        ne = self._next_event
+                        self._next_event = None
+                        ne.send(result)
         except api.GreenletExit, e:
             # we're printing this out to see if it ever happens
             # in practice
@@ -354,6 +366,22 @@ class CoroutinePool(pools.Pool):
         """
         self._execute(None, func, args, kw)
 
+    def wait(self):
+        """Wait for the next execute in the pool to complete,
+        and return the result.
+
+        You must pass track_events=True to the CoroutinePool constructor
+        in order to use this method.
+        """
+        assert self._tracked_events is not None, (
+            "Must pass track_events=True to the constructor to use CoroutinePool.wait()")
+        if self._next_event is None:
+            result = self._tracked_events.pop(0)
+            if not self._tracked_events:
+                self._next_event = event()
+            return result
+        return self._next_event.wait()
+
     def killall(self):
         for g in self._greenlets:
             api.kill(g)

eventlet/coros_test.py

@@ -110,6 +110,7 @@ class TestEvent(tests.TestCase):
         api.exc_after(0.001, api.TimeoutError)
         self.assertRaises(api.TimeoutError, evt.wait)
 
+
 class TestCoroutinePool(tests.TestCase):
     mode = 'static'
     def setUp(self):
@@ -206,14 +207,23 @@ class TestCoroutinePool(tests.TestCase):
             t.cancel()
         finally:
             sys.stderr = normal_err
-        
+
-        
+    def test_track_events(self):
+        pool = coros.CoroutinePool(track_events=True)
+        for x in range(6):
+            pool.execute(lambda n: n, x)
+        t = api.exc_after(10, RuntimeError)
+        for y in range(6):
+            pool.wait()
+        t.cancel()
+
 
 class IncrActor(coros.Actor):
     def received(self, evt):
         self.value = getattr(self, 'value', 0) + 1
         if evt: evt.send()
 
+
 class TestActor(tests.TestCase):
     mode = 'static'
     def setUp(self):
@@ -277,7 +287,6 @@ class TestActor(tests.TestCase):
         for evt in waiters:
             evt.wait()
         self.assertEqual(msgs, [1,2,3,4,5])
-        
 
     def test_raising_received(self):
         msgs = []
@@ -325,5 +334,6 @@ class TestActor(tests.TestCase):
         self.assertEqual(total[0], 3)
         self.assertEqual(self.actor._pool.free(), 2)
 
+
 if __name__ == '__main__':
     tests.main()