--- a/testing/mozbase/mozprocess/mozprocess/processhandler.py
+++ b/testing/mozbase/mozprocess/mozprocess/processhandler.py
@@ -390,22 +390,24 @@ falling back to not using job objects fo
                     if countdowntokill != 0:
                         diff = datetime.now() - countdowntokill
                         # Arbitrarily wait 3 minutes for windows to get its act together
                         # Windows sometimes takes a small nap between notifying the
                         # IO Completion port and actually killing the children, and we
                         # don't want to mistake that situation for the situation of an unexpected
                         # parent abort (which is what we're looking for here).
                         if diff.seconds > self.MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY:
+                            print >> sys.stderr, "WARNING | IO Completion Port failed to signal process shutdown"
                             print >> sys.stderr, "Parent process %s exited with children alive:" % self.pid
                             print >> sys.stderr, "PIDS: %s" %  ', '.join([str(i) for i in self._spawned_procs])
-                            print >> sys.stderr, "Attempting to kill them..."
+                            print >> sys.stderr, "Attempting to kill them, but no guarantee of success"
 
                             self.kill()
                             self._process_events.put({self.pid: 'FINISHED'})
+                            break
 
                     if not portstatus:
                         # Check to see what happened
                         errcode = winprocess.GetLastError()
                         if errcode == winprocess.ERROR_ABANDONED_WAIT_0:
                             # Then something has killed the port, break the loop
                             print >> sys.stderr, "IO Completion Port unexpectedly closed"
                             self._process_events.put({self.pid: 'FINISHED'})
@@ -467,17 +469,17 @@ falling back to not using job objects fo
                     self.returncode = winprocess.GetExitCodeProcess(self._handle)
                 else:
                     # Dude, the process is like totally dead!
                     return self.returncode
 
                 threadalive = False
                 if hasattr(self, "_procmgrthread"):
                     threadalive = self._procmgrthread.is_alive()
-                if self._job and threadalive:
+                if self._job and threadalive and threading.current_thread() != self._procmgrthread:
                     self.debug("waiting with IO completion port")
                     # Then we are managing with IO Completion Ports
                     # wait on a signal so we know when we have seen the last
                     # process come through.
                     # We use queues to synchronize between the thread and this
                     # function because events just didn't have robust enough error
                     # handling on pre-2.7 versions
                     err = None