got it so that the master must send an explicit kill for the slaves to shutdown

bin/master.py

@@ -47,6 +47,15 @@ def run_queries(count, order = 3, extra_points = 8, verbose = False):
 
   return (r, submit_end - submit_start, receive_end - receive_start)
 
+def clean_up(inq, expected_participants, shutdown = False):
+  """
+    I replace the normal first argument to the inq with None, and then do some
+    code branching based on the second paramter, which is shutdown
+  """
+  for i in xrange(expected_participants):
+    inq.put([None, shutdown, None, None])
+
+
 if __name__ == '__main__':
   parser = OptionParser(usage = "usage: %s [options] <server> <expected participants> <interp count>")
 
@@ -54,6 +63,10 @@ if __name__ == '__main__':
     action="store_true", dest="verbose", default=False,
     help="verbose flag (display progress bar: %default)")
 
+  parser.add_option("-l", "--last-time",
+    action="store_true", dest="last", default=False,
+    help="when finished, send shutdown signal to <expected participants> nodes (default: %default)")
+
   parser.add_option('-p', '--port',
     type="int", dest="port", default=6666,
     help="specify the port to use on the server (default: %default)")
@@ -94,8 +107,7 @@ if __name__ == '__main__':
   results, submit, receive = run_queries(count, order = options.order, extra_points = options.extra, verbose = options.verbose)
 
   # shut down all participants
-  for i in xrange(expected_participants):
-    inq.put([None] * 4)
+  clean_up(inq, expected_participants)
 
   # post processing
   stats = {}
@@ -122,3 +134,6 @@ if __name__ == '__main__':
     'results' : npresults,
   }
   s.close()
+
+  if options.last:
+    clean_up(inq, expected_participants, shutdown = True)

bin/slave.py

@@ -22,7 +22,7 @@ def work(inq, outq, g, myname):
   while True:
     i, o, e, X = inq.get()
     if i == None:
-      break
+      return o
     a = g.run_baker(X, order = o, extra_points = e)
     outq.put((i, myname, a['qlin'], a['error'], a['final'], exact(X)))
 
@@ -56,4 +56,6 @@ if __name__ == '__main__':
   g.q = np.array([exact(x) for x in g.verts])
 
   myname = options.label
-  work(inq, outq, g, myname)
+  shutdown = False
+  while not shutdown:
+    shutdown = work(inq, outq, g, myname)