[Andoid] Threaded TestRunner creation and SetUp and TearDown calls.

build/android/pylib/utils/reraiser_thread.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.
+
+"""Thread and ThreadGroup that reraise exceptions on the main thread."""
+
+import sys
+import threading
+
+
+class ReraiserThread(threading.Thread):
+  """Thread class that can reraise exceptions."""
+  def __init__(self, func, args=[], kwargs={}):
+    super(ReraiserThread, self).__init__()
+    self.daemon = True
+    self._func = func
+    self._args = args
+    self._kwargs = kwargs
+    self._exc_info = None
+
+  def ReraiseIfException(self):
+    """Reraise exception if an exception was raised in the thread."""
+    if self._exc_info:
+      raise self._exc_info[0], self._exc_info[1], self._exc_info[2]
+
+  #override
+  def run(self):
+    """Overrides Thread.run() to add support for reraising exceptions."""
+    try:
+      self._func(*self._args, **self._kwargs)
+    except:
+      self._exc_info = sys.exc_info()
+      raise
+
+
+class ReraiserThreadGroup(object):
+  """A group of ReraiserThread objects."""
+  def __init__(self, threads=[]):
+    """Initialize thread group.
+
+    Args:
+      threads: a list of ReraiserThread objects; defaults to empty.
+    """
+    self._threads = threads
+
+  def Add(self, thread):
+    """Add a thread to the group.
+
+    Args:
+      thread: a ReraiserThread object.
+    """
+    self._threads.append(thread)
+
+  def StartAll(self):
+    """Start all threads."""
+    for thread in self._threads:
+      thread.start()
+
+  def JoinAll(self):
+    """Join all threads.
+
+    Reraises exceptions raised by the child threads and supports
+    breaking immediately on exceptions raised on the main thread.
+    """
+    alive_threads = self._threads[:]
+    while alive_threads:
+      for thread in alive_threads[:]:
+        # Allow the main thread to periodically check for interrupts.
+        thread.join(0.1)
+        if not thread.isAlive():
+          alive_threads.remove(thread)
+    # All threads are allowed to complete before reraising exceptions.
+    for thread in self._threads:
+      thread.ReraiseIfException()