Fix silent failures in test runner that lead to long timeouts

build/android/pylib/perf/test_runner.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Runs perf tests.
 
 Our buildbot infrastructure requires each slave to run steps serially.
 This is sub-optimal for android, where these steps can run independently on
 multiple connected devices.
 
@@ skipping 31 matching lines @@
 """
 
 import datetime
 import logging
 import os
 import pickle
 import sys
 import threading
 import time
 
+from pylib import cmd_helper
 from pylib import constants
 from pylib import forwarder
-from pylib import pexpect
 from pylib.base import base_test_result
 from pylib.base import base_test_runner
 
 
 def PrintTestOutput(test_name):
   """Helper method to print the output of previously executed test_name.
 
   Args:
     test_name: name of the test that has been previously executed.
 
@@ skipping 128 matching lines @@
       full_cmd = 'echo %s' % cmd
 
     logfile = sys.stdout
     if self._options.single_step:
       # Just print a heart-beat so that the outer buildbot scripts won't timeout
       # without response.
       logfile = _HeartBeatLogger()
     cwd = os.path.abspath(constants.DIR_SOURCE_ROOT)
     if full_cmd.startswith('src/'):
       cwd = os.path.abspath(os.path.join(constants.DIR_SOURCE_ROOT, os.pardir))
-    output, exit_code = pexpect.run(
-        full_cmd, cwd=cwd,
-        withexitstatus=True, logfile=logfile, timeout=timeout,
-        env=os.environ)
-    if self._options.single_step:
-      # Stop the logger.
-      logfile.stop()
+    try:
+      exit_code, output = cmd_helper.GetCmdStatusAndOutputWithTimeout(
+          full_cmd, timeout, cwd=cwd, shell=True, logfile=logfile)
+    finally:
+      if self._options.single_step:
+        logfile.stop()
     end_time = datetime.datetime.now()
     if exit_code is None:
       exit_code = -1
     logging.info('%s : exit_code=%d in %d secs at %s',
                  test_name, exit_code, (end_time - start_time).seconds,
                  self.device.old_interface.GetDevice())
     result_type = base_test_result.ResultType.FAIL
     if exit_code == 0:
       result_type = base_test_result.ResultType.PASS
     actual_exit_code = exit_code
@@ skipping 27 matching lines @@
     Returns:
       A tuple of (TestRunResults, retry).
     """
     _, result_type = self._LaunchPerfTest(test_name)
     results = base_test_result.TestRunResults()
     results.AddResult(base_test_result.BaseTestResult(test_name, result_type))
     retry = None
     if not results.DidRunPass():
       retry = test_name
     return results, retry