Upstream test sharder.

build/android/base_test_sharder.py

Index: build/android/base_test_sharder.py
diff --git a/build/android/base_test_sharder.py b/build/android/base_test_sharder.py
new file mode 100644
index 0000000000000000000000000000000000000000..e6d739813c04715990075f03c4fc49fb52852f95
--- /dev/null
+++ b/build/android/base_test_sharder.py
@@ -0,0 +1,108 @@
+#!/usr/bin/python
+# Copyright (c) 2011 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.
+
+
+import logging
+import multiprocessing
+
+from test_result import *
+
+
+def _ShardedTestRunnable(test):
+  """Standalone function needed by multiprocessing.Pool."""
+  log_format = '[' + test.device + '] # %(asctime)-15s: %(message)s'
+  if logging.getLogger().handlers:
+    logging.getLogger().handlers[0].setFormatter(logging.Formatter(log_format))
+  else:
+    logging.basicConfig(format=log_format)
+  return test.Run()
+
+
+def SetTestsContainer(tests_container):
+  """Sets tests container.
+
+  multiprocessing.Queue can't be pickled across processes, so we need to set
+  this as a 'global', per process, via multiprocessing.Pool.
+  """
+  BaseTestSharder.tests_container = tests_container
+
+
+class BaseTestSharder(object):
+  """Base class for sharding tests across multiple devices.
+
+  Args:
+    attached_devices: A list of attached devices.
+  """
+  # See more in SetTestsContainer.
+  tests_container = None
+
+  def __init__(self, attached_devices):
+    self.attached_devices = attached_devices
+    self.retries = 1
+    self.tests = []
+
+  def CreateShardedTestRunner(self, device, index):
+    """Factory function to create a suite-specific test runner.
+
+    Args:
+      device: Device serial where this shard will run
+      index: Index of this device in the pool.
+
+    Returns:
+      An object of BaseTestRunner type (that can provide a "Run()" method).
+    """
+    pass
+
+  def SetupSharding(self, tests):
+    """Called before starting the shards."""
+    pass
+
+  def OnTestsCompleted(self, test_runners, test_results):
+    """Notifies that we completed the tests."""
+    pass
+
+  def RunShardedTests(self):
+    """Runs the tests in all connected devices.
+
+    Returns:
+      A TestResults object.
+    """
+    logging.warning('*' * 80)
+    logging.warning('Sharding in ' + str(len(self.attached_devices)) +
+                    ' devices.')
+    logging.warning('Note that the output is not synchronized.')
+    logging.warning('Look for the "Final result" banner in the end.')
+    logging.warning('*' * 80)
+    final_results = TestResults()
+    for retry in xrange(self.retries):
+      logging.warning('Try %d of %d' % (retry + 1, self.retries))
+      self.SetupSharding(self.tests)
+      test_runners = []
+      for index, device in enumerate(self.attached_devices):
+        logging.warning('*' * 80)
+        logging.warning('Creating shard %d for %s' % (index, device))
+        logging.warning('*' * 80)
+        test_runner = self.CreateShardedTestRunner(device, index)
+        test_runners += [test_runner]
+      logging.warning('Starting...')
+      pool = multiprocessing.Pool(len(self.attached_devices),
+                                  SetTestsContainer,
+                                  [BaseTestSharder.tests_container])
+      results_lists = pool.map(_ShardedTestRunnable, test_runners)
+      test_results = TestResults.FromTestResults(results_lists)
+      if retry == self.retries - 1:
+        all_passed = final_results.ok + test_results.ok
+        final_results = test_results
+        final_results.ok = all_passed
+        break
+      else:
+        final_results.ok += test_results.ok
+        self.tests = []
+        for t in test_results.GetAllBroken():
+          self.tests += [t.name]
+        if not self.tests:
+          break
+    self.OnTestsCompleted(test_runners, final_results)
+    return final_results