Do a better job parallelizing the inital batch of tests when the

number of nodes is more than half the number of tests. This makes it
possible, for example, to run all tests in parallel, where previous
the maximum parallelization was half of all tests.

xdist/slavemanage.py

@@ -207,6 +207,7 @@ class SlaveController(object):
         self.config = config
         self.slaveinput = {'slaveid': gateway.id}
         self._down = False
+        self._shutdown_sent = False
         self.log = py.log.Producer("slavectl-%s" % gateway.id)
         if not self.config.option.debug:
             py.log.setconsumer(self.log._keywords, None)
@@ -214,6 +215,10 @@ class SlaveController(object):
     def __repr__(self):
         return "<%s %s>" % (self.__class__.__name__, self.gateway.id,)
 
+    @property
+    def shutting_down(self):
+        return self._down or self._shutdown_sent
+
     def setup(self):
         self.log("setting up slave session")
         spec = self.gateway.spec
@@ -256,6 +261,7 @@ class SlaveController(object):
                 self.sendcommand("shutdown")
             except IOError:
                 pass
+            self._shutdown_sent = True
 
     def sendcommand(self, name, **kwargs):
         """ send a named parametrized command to the other side. """