parallel: obey iterator protocol

Once it raises StopIteration, it must continue to do so on subsequent calls to next().

diff --git a/teuthology/parallel.py b/teuthology/parallel.py
index c3463a04080756a5e336abb8a4799dada42b4756..a3693ea6041cbcdbd38c2a271cd33ceea9beec01 100644 (file)
--- a/teuthology/parallel.py
+++ b/teuthology/parallel.py
@@ -36,6 +36,7 @@ class parallel(object):
         self.results = gevent.queue.Queue()
         self.count = 0
         self.any_spawned = False
+        self.iteration_stopped = False
 
     def spawn(self, func, *args, **kwargs):
         self.count += 1
@@ -65,10 +66,12 @@ class parallel(object):
         return self
 
     def next(self):
-        if not self.any_spawned:
+        if not self.any_spawned or self.iteration_stopped:
             raise StopIteration()
         result = self.results.get()
         if isinstance(result, BaseException):
+            if isinstance(result, StopIteration):
+                self.iteration_stopped = True
             raise result
         return result