--- a/testing/mozbase/mozrunner/mozrunner/base/device.py
+++ b/testing/mozbase/mozrunner/mozrunner/base/device.py
@@ -77,57 +77,73 @@ class DeviceRunner(BaseRunner):
         self.device.wait_for_net()
 
         if not self.device.wait_for_net():
             raise Exception("Network did not come up when starting device")
 
         pid = BaseRunner.start(self, *args, **kwargs)
 
         timeout = 10  # seconds
-        starttime = datetime.datetime.now()
-        while datetime.datetime.now() - starttime < datetime.timedelta(seconds=timeout):
-            if self.is_running():
-                break
-            time.sleep(1)
+        end_time = datetime.datetime.now() + datetime.timedelta(seconds=timeout)
+        while not self.is_running() and datetime.datetime.now() < end_time:
+            time.sleep(.1)
         else:
             print("timed out waiting for '%s' process to start" % self.app_ctx.remote_process)
 
         if not self.device.wait_for_net():
             raise Exception("Failed to get a network connection")
         return pid
 
     def stop(self, sig=None):
-        def _wait_for_shutdown(pid, timeout=10):
-            start_time = datetime.datetime.now()
-            end_time = datetime.timedelta(seconds=timeout)
-            while datetime.datetime.now() - start_time < end_time:
-                if self.is_running() != pid:
-                    return True
-                time.sleep(1)
-            return False
+        if self.is_running():
+            timeout = 10
 
-        remote_pid = self.is_running()
-        if remote_pid:
-            self.app_ctx.dm.killProcess(
-                self.app_ctx.remote_process, sig=sig)
-            if not _wait_for_shutdown(remote_pid) and sig is not None:
+            self.app_ctx.dm.killProcess(self.app_ctx.remote_process, sig=sig)
+            if self.wait(timeout) is None and sig is not None:
                 print("timed out waiting for '%s' process to exit, trying "
                       "without signal {}".format(
                           self.app_ctx.remote_process, sig))
 
             # need to call adb stop otherwise the system will attempt to
             # restart the process
-            remote_pid = self.is_running() or remote_pid
             self.app_ctx.stop_application()
-            if not _wait_for_shutdown(remote_pid):
+            if self.wait(timeout) is None:
                 print("timed out waiting for '%s' process to exit".format(
                     self.app_ctx.remote_process))
 
-    def is_running(self):
-        return self.app_ctx.dm.processExist(self.app_ctx.remote_process)
+    @property
+    def returncode(self):
+        """The returncode of the remote process.
+
+        A value of None indicates the process is still running. Otherwise 0 is
+        returned, because there is no known way yet to retrieve the real exit code.
+        """
+        if self.app_ctx.dm.processExist(self.app_ctx.remote_process) is None:
+            return 0
+
+        return None
+
+    def wait(self, timeout=None):
+        """Wait for the remote process to exit.
+
+        :param timeout: if not None, will return after timeout seconds.
+
+        :returns: the process return code or None if timeout was reached
+                  and the process is still running.
+        """
+        end_time = None
+        if timeout is not None:
+            end_time = datetime.datetime.now() + datetime.timedelta(seconds=timeout)
+
+        while self.is_running():
+            if end_time is not None and datetime.datetime.now() > end_time:
+                break
+            time.sleep(.1)
+
+        return self.returncode
 
     def on_output(self, line):
         match = re.findall(r"TEST-START \| ([^\s]*)", line)
         if match:
             self.last_test = match[-1]
 
     def on_timeout(self):
         self.stop(sig=signal.SIGABRT)