Check if device disconnects every time the last test of a revision fails

scripts/slave/recipe_modules/auto_bisect/revision_state.py

 # Copyright 2015 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.
 
 """An interface for holding state and result of revisions in a bisect job.
 
 When implementing support for tests other than perf, one should extend this
 class so that the bisect module and recipe can use it.
 
 See perf_revision_state for an example.
@@ skipping 167 matching lines @@
         'From': lambda *args: None,
     }
     return deps_data
 
   def _read_content(self, url, file_name, branch):   # pragma: no cover
     """Uses gitiles recipe module to download and read file contents."""
     try:
       return self.bisector.api.m.gitiles.download_file(
           repository_url=url, file_path=file_name, branch=branch)
     except TypeError:
-      print 'Could not read content for %s/%s/%s' % (url, file_name, branch) 
+      print 'Could not read content for %s/%s/%s' % (url, file_name, branch)
       return None
 
   def read_deps(self, recipe_tester_name):
     """Sets the dependencies for this revision from the contents of DEPS."""
     api = self.bisector.api
     if self.deps:
       return
     if self.bisector.internal_bisect:  # pragma: no cover
       self.deps_file_contents = self._read_content(
           depot_config.DEPOT_DEPS_NAME[self.depot_name]['url'],
@@ skipping 149 matching lines @@
     # stdout of the command, and 'results' is itself a dict with the key
     # 'values' unless the test failed, in which case 'results' will contain
     # the 'error' key explaining the type of error.
     results = test_results['results']
     if results.get('errors'):
       self.status = RevisionState.FAILED
       if 'MISSING_METRIC' in results.get('errors'):  # pragma: no cover
         self.bisector.surface_result('MISSING_METRIC')
       return
     self.values += results['values']
+    api = self.bisector.api
+    if test_results['retcodes'][-1] != 0 and (

[sullivan, 2016/08/08 22:13:28]

Is test_results['retcodes'] always defined? Is it always an array with a length?
Roberto, can you help us understand how defensively to program here?

[RobertoCN, 2016/08/08 22:46:42]

it will always be a list. And as long as the test runs once, it will not be
empty. I guess it won't hurt to do:
if test_results.get('retcodes') and test_results['retcodes'][-1] !=0....

[Ziqi Xiong, 2016/08/09 18:59:11]

Done.

+        api.m.chromium.c.TARGET_PLATFORM == 'android'): #pragma: no cover
+      api.m.chromium_android.device_status()

[sullivan, 2016/08/08 22:13:28]

What does device_status() do?

[Ziqi Xiong, 2016/08/09 18:59:11]

It rechecks the devices connected to host and then updates
api.m.chromium_android.devices.

+      current_connected_devices = api.m.chromium_android.devices
+      current_device = api.m.bisect_tester.device_to_test
+      if current_device not in current_connected_devices:
+        raise api.m.step.StepFailure('Test device disconnected.')
     if self.bisector.is_return_code_mode():
       retcodes = test_results['retcodes']
       self.overall_return_code = 0 if all(v == 0 for v in retcodes) else 1
       # Keeping mean_value for compatibility with dashboard.
       # TODO(robertocn): refactor mean_value, specially when uploading results
       # to dashboard.
       self.mean_value = self.overall_return_code
     elif self.values:
       api = self.bisector.api
       self.mean_value = api.m.math_utils.mean(self.values)
@@ skipping 219 matching lines @@
     else:
       next_revision_to_test.retest()
 
   def __repr__(self):
     if self.overall_return_code is not None:
       return ('RevisionState(rev=%s, values=%r, overall_return_code=%r, '
               'std_dev=%r)') % (self.revision_string(), self.values,
                                 self.overall_return_code, self.std_dev)
     return ('RevisionState(rev=%s, values=%r, mean_value=%r, std_dev=%r)' % (
         self.revision_string(), self.values, self.mean_value, self.std_dev))