[Android] Support generic parallel execution across devices.

BUG=267773

Review URL: https://codereview.chromium.org/290573004

git-svn-id: http://src.chromium.org/svn/trunk/src/build@272159 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/adb_install_apk.py

@@ -6,7 +6,6 @@
 
 """Utility script to install APKs from the command line quickly."""
 
-import multiprocessing
 import optparse
 import os
 import sys
@@ -50,13 +49,6 @@ def ValidateInstallAPKOption(option_parser, options):
                                options.apk)
 
 
-def _InstallApk(args):
-  apk_path, apk_package, keep_data, device = args
-  device_utils.DeviceUtils(device=device).old_interface.ManagedInstall(
-      apk_path, keep_data, apk_package)
-  print '-----  Installed on %s  -----' % device
-
-
 def main(argv):
   parser = optparse.OptionParser()
   AddInstallAPKOption(parser)
@@ -73,13 +65,10 @@ def main(argv):
   if not options.apk_package:
     options.apk_package = apk_helper.GetPackageName(options.apk)
 
-  pool = multiprocessing.Pool(len(devices))
+  device_utils.DeviceUtils.parallel(devices).old_interface.ManagedInstall(
-  # Send a tuple (apk_path, apk_package, device) per device.
+      options.apk, options.keep_data, options.apk_package).pFinish(None)
-  pool.map(_InstallApk, zip([options.apk] * len(devices),
-                            [options.apk_package] * len(devices),
-                            [options.keep_data] * len(devices),
-                            devices))
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))
+

android/provision_devices.py

@@ -24,6 +24,10 @@ from pylib import device_settings
 from pylib.cmd_helper import GetCmdOutput
 from pylib.device import device_utils
 
+sys.path.append(os.path.join(constants.DIR_SOURCE_ROOT,
+                             'third_party', 'android_testrunner'))
+import errors
+
 def KillHostHeartbeat():
   ps = subprocess.Popen(['ps', 'aux'], stdout = subprocess.PIPE)
   stdout, _ = ps.communicate()
@@ -172,7 +176,11 @@ def main(argv):
     for device_serial in devices:
       device = device_utils.DeviceUtils(device_serial)
       WipeDeviceData(device)
-    device_utils.RebootDevices()
+    try:
+      (device_utils.DeviceUtils.parallel(devices)
+          .old_interface.Reboot(True).pFinish(None))
+    except errors.DeviceUnresponsiveError:
+      pass
   else:
     ProvisionDevices(options)
 

android/pylib/device/device_utils.py

@@ -9,52 +9,16 @@ Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=W0613
 
-import multiprocessing
-import os
-import sys
-
 import pylib.android_commands
 from pylib.device import adb_wrapper
 from pylib.device import decorators
 from pylib.device import device_errors
-
+from pylib.utils import parallelizer
-CHROME_SRC_DIR = os.path.abspath(
-    os.path.join(os.path.dirname(__file__), '..', '..', '..', '..'))
-sys.path.append(os.path.join(
-    CHROME_SRC_DIR, 'third_party', 'android_testrunner'))
-import errors
 
 _DEFAULT_TIMEOUT = 30
 _DEFAULT_RETRIES = 3
 
 
-# multiprocessing map_async requires a top-level function for pickle library.
-def RebootDeviceSafe(device):
-  """Reboot a device, wait for it to start, and squelch timeout exceptions."""
-  try:
-    DeviceUtils(device).old_interface.Reboot(True)
-  except errors.DeviceUnresponsiveError as e:
-    return e
-
-
-def RebootDevices():
-  """Reboot all attached and online devices."""
-  devices = pylib.android_commands.GetAttachedDevices()
-  print 'Rebooting: %s' % devices
-  if devices:
-    pool = multiprocessing.Pool(len(devices))
-    results = pool.map_async(RebootDeviceSafe, devices).get(99999)
-
-    for device, result in zip(devices, results):
-      if result:
-        print '%s failed to startup.' % device
-
-    if any(results):
-      print 'RebootDevices() Warning: %s' % results
-    else:
-      print 'Reboots complete.'
-
-
 @decorators.WithExplicitTimeoutAndRetries(
     _DEFAULT_TIMEOUT, _DEFAULT_RETRIES)
 def GetAVDs():
@@ -150,3 +114,26 @@ class DeviceUtils(object):
       raise device_errors.CommandFailedError(
           'adb root', 'Could not enable root.')
 
+  def __str__(self):
+    """Returns the device serial."""
+    return self.old_interface.GetDevice()
+
+  @staticmethod
+  def parallel(devices):
+    """ Creates a Parallelizer to operate over the provided list of devices.
+
+    If |devices| is either |None| or an empty list, the Parallelizer will
+    operate over all attached devices.
+
+    Args:
+      devices: A list of either DeviceUtils instances or objects from
+               from which DeviceUtils instances can be constructed.
+    Returns:
+      A Parallelizer operating over |devices|.
+    """
+    if not devices or len(devices) == 0:
+      devices = pylib.android_commands.AndroidCommands.GetAttachedDevices()
+    return parallelizer.Parallelizer([
+        d if isinstance(d, DeviceUtils) else DeviceUtils(d)
+        for d in devices])
+

android/pylib/utils/parallelizer.py

@@ -0,0 +1,196 @@
+# Copyright 2014 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.
+
+""" Wrapper that allows method execution in parallel.
+
+This class wraps a list of objects of the same type, emulates their
+interface, and executes any functions called on the objects in parallel
+in ReraiserThreads.
+
+This means that, given a list of objects:
+
+  class Foo:
+    def __init__(self):
+      self.baz = Baz()
+
+    def bar(self, my_param):
+      // do something
+
+  list_of_foos = [Foo(1), Foo(2), Foo(3)]
+
+we can take a sequential operation on that list of objects:
+
+  for f in list_of_foos:
+    f.bar('Hello')
+
+and run it in parallel across all of the objects:
+
+  Parallelizer(list_of_foos).bar('Hello')
+
+It can also handle (non-method) attributes of objects, so that this:
+
+  for f in list_of_foos:
+    f.baz.myBazMethod()
+
+can be run in parallel with:
+
+  Parallelizer(list_of_foos).baz.myBazMethod()
+
+Because it emulates the interface of the wrapped objects, a Parallelizer
+can be passed to a method or function that takes objects of that type:
+
+  def DoesSomethingWithFoo(the_foo):
+    the_foo.bar('Hello')
+    the_foo.bar('world')
+    the_foo.baz.myBazMethod
+
+  DoesSomethingWithFoo(Parallelizer(list_of_foos))
+
+Note that this class spins up a thread for each object. Using this class
+to parallelize operations that are already fast will incur a net performance
+penalty.
+
+"""
+# pylint: disable=W0613
+
+from pylib.utils import reraiser_thread
+from pylib.utils import watchdog_timer
+
+_DEFAULT_TIMEOUT = 30
+_DEFAULT_RETRIES = 3
+
+
+class Parallelizer(object):
+  """Allows parallel execution of method calls across a group of objects."""
+
+  def __init__(self, objs):
+    assert (objs is not None and len(objs) > 0), (
+        "Passed empty list to 'Parallelizer'")
+    self._orig_objs = objs
+    self._objs = objs
+
+  def __getattr__(self, name):
+    """Emulate getting the |name| attribute of |self|.
+
+    Args:
+      name: The name of the attribute to retrieve.
+    Returns:
+      A Parallelizer emulating the |name| attribute of |self|.
+    """
+    self.pGet(None)
+
+    r = Parallelizer(self._orig_objs)
+    r._objs = [getattr(o, name) for o in self._objs]
+    return r
+
+  def __getitem__(self, index):
+    """Emulate getting the value of |self| at |index|.
+
+    Returns:
+      A Parallelizer emulating the value of |self| at |index|.
+    """
+    self.pGet(None)
+
+    r = Parallelizer(self._orig_objs)
+    r._objs = [o[index] for o in self._objs]
+    return r
+
+  def __call__(self, *args, **kwargs):
+    """Emulate calling |self| with |args| and |kwargs|.
+
+    Note that this call is asynchronous. Call pFinish on the return value to
+    block until the call finishes.
+
+    Returns:
+      A Parallelizer wrapping the ReraiserThreadGroup running the call in
+      parallel.
+    Raises:
+      AttributeError if the wrapped objects aren't callable.
+    """
+    self.pGet(None)
+
+    if not self._objs:
+      raise AttributeError('Nothing to call.')
+    for o in self._objs:
+      if not callable(o):
+        raise AttributeError("'%s' is not callable" % o.__name__)
+
+    r = Parallelizer(self._orig_objs)
+    r._objs = reraiser_thread.ReraiserThreadGroup(
+        [reraiser_thread.ReraiserThread(
+            o, args=args, kwargs=kwargs,
+            name='%s.%s' % (str(d), o.__name__))
+         for d, o in zip(self._orig_objs, self._objs)])
+    r._objs.StartAll() # pylint: disable=W0212
+    return r
+
+  def pFinish(self, timeout):
+    """Finish any outstanding asynchronous operations.
+
+    Args:
+      timeout: The maximum number of seconds to wait for an individual
+               result to return, or None to wait forever.
+    Returns:
+      self, now emulating the return values.
+    """
+    self._assertNoShadow('pFinish')
+    if isinstance(self._objs, reraiser_thread.ReraiserThreadGroup):
+      self._objs.JoinAll()
+      self._objs = self._objs.GetAllReturnValues(
+          watchdog_timer.WatchdogTimer(timeout))
+    return self
+
+  def pGet(self, timeout):
+    """Get the current wrapped objects.
+
+    Args:
+      timeout: Same as |pFinish|.
+    Returns:
+      A list of the results, in order of the provided devices.
+    Raises:
+      Any exception raised by any of the called functions.
+    """
+    self._assertNoShadow('pGet')
+    self.pFinish(timeout)
+    return self._objs
+
+  def _assertNoShadow(self, attr_name):
+    """Ensures that |attr_name| isn't shadowing part of the wrapped obejcts.
+
+    If the wrapped objects _do_ have an |attr_name| attribute, it will be
+    inaccessible to clients.
+
+    Args:
+      attr_name: The attribute to check.
+    Raises:
+      AssertionError if the wrapped objects have an attribute named 'attr_name'
+      or '_assertNoShadow'.
+    """
+    if isinstance(self._objs, reraiser_thread.ReraiserThreadGroup):
+      assert(not hasattr(self._objs, '_assertNoShadow'))
+      assert(not hasattr(self._objs, 'pGet'))
+    else:
+      assert(not any(hasattr(o, '_assertNoShadow') for o in self._objs))
+      assert(not any(hasattr(o, 'pGet') for o in self._objs))
+
+
+class SyncParallelizer(Parallelizer):
+  """A Parallelizer that blocks on function calls."""
+
+  #override
+  def __call__(self, *args, **kwargs):
+    """Emulate calling |self| with |args| and |kwargs|.
+
+    Note that this call is synchronous.
+
+    Returns:
+      A Parallelizer emulating the value returned from calling |self| with
+      |args| and |kwargs|.
+    Raises:
+      AttributeError if the wrapped objects aren't callable.
+    """
+    r = super(SyncParallelizer, self).__call__(*args, **kwargs)
+    r.pFinish(None)
+    return r
+

android/pylib/utils/parallelizer_test.py

@@ -0,0 +1,166 @@
+# Copyright 2014 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.
+
+"""Unit tests for the contents of parallelizer.py."""
+
+# pylint: disable=W0212
+# pylint: disable=W0613
+
+import os
+import tempfile
+import time
+import unittest
+
+from pylib.utils import parallelizer
+
+
+class ParallelizerTestObject(object):
+  """Class used to test parallelizer.Parallelizer."""
+
+  parallel = parallelizer.Parallelizer
+
+  def __init__(self, thing, completion_file_name=None):
+    self._thing = thing
+    self._completion_file_name = completion_file_name
+    self.helper = ParallelizerTestObjectHelper(thing)
+
+  @staticmethod
+  def doReturn(what):
+    return what
+
+  @classmethod
+  def doRaise(cls, what):
+    raise what
+
+  def doSetTheThing(self, new_thing):
+    self._thing = new_thing
+
+  def doReturnTheThing(self):
+    return self._thing
+
+  def doRaiseTheThing(self):
+    raise self._thing
+
+  def doRaiseIfExceptionElseSleepFor(self, sleep_duration):
+    if isinstance(self._thing, Exception):
+      raise self._thing
+    time.sleep(sleep_duration)
+    self._write_completion_file()
+    return self._thing
+
+  def _write_completion_file(self):
+    if self._completion_file_name and len(self._completion_file_name):
+      with open(self._completion_file_name, 'w+b') as completion_file:
+        completion_file.write('complete')
+
+  def __getitem__(self, index):
+    return self._thing[index]
+
+  def __str__(self):
+    return type(self).__name__
+
+
+class ParallelizerTestObjectHelper(object):
+
+  def __init__(self, thing):
+    self._thing = thing
+
+  def doReturnStringThing(self):
+    return str(self._thing)
+
+
+class ParallelizerTest(unittest.TestCase):
+
+  def testInitWithNone(self):
+    with self.assertRaises(AssertionError):
+      parallelizer.Parallelizer(None)
+
+  def testInitEmptyList(self):
+    with self.assertRaises(AssertionError):
+      parallelizer.Parallelizer([])
+
+  def testMethodCall(self):
+    test_data = ['abc_foo', 'def_foo', 'ghi_foo']
+    expected = ['abc_bar', 'def_bar', 'ghi_bar']
+    r = parallelizer.Parallelizer(test_data).replace('_foo', '_bar').pGet(0.1)
+    self.assertEquals(expected, r)
+
+  def testMutate(self):
+    devices = [ParallelizerTestObject(True) for _ in xrange(0, 10)]
+    self.assertTrue(all(d.doReturnTheThing() for d in devices))
+    ParallelizerTestObject.parallel(devices).doSetTheThing(False).pFinish(1)
+    self.assertTrue(not any(d.doReturnTheThing() for d in devices))
+
+  def testAllReturn(self):
+    devices = [ParallelizerTestObject(True) for _ in xrange(0, 10)]
+    results = ParallelizerTestObject.parallel(
+        devices).doReturnTheThing().pGet(1)
+    self.assertTrue(isinstance(results, list))
+    self.assertEquals(10, len(results))
+    self.assertTrue(all(results))
+
+  def testAllRaise(self):
+    devices = [ParallelizerTestObject(Exception('thing %d' % i))
+               for i in xrange(0, 10)]
+    p = ParallelizerTestObject.parallel(devices).doRaiseTheThing()
+    with self.assertRaises(Exception):
+      p.pGet(1)
+
+  def testOneFailOthersComplete(self):
+    parallel_device_count = 10
+    exception_index = 7
+    exception_msg = 'thing %d' % exception_index
+
+    try:
+      completion_files = [tempfile.NamedTemporaryFile(delete=False)
+                          for _ in xrange(0, parallel_device_count)]
+      devices = [
+          ParallelizerTestObject(
+              i if i != exception_index else Exception(exception_msg),
+              completion_files[i].name)
+          for i in xrange(0, parallel_device_count)]
+      for f in completion_files:
+        f.close()
+      p = ParallelizerTestObject.parallel(devices)
+      with self.assertRaises(Exception) as e:
+        p.doRaiseIfExceptionElseSleepFor(2).pGet(3)
+      self.assertTrue(exception_msg in str(e.exception))
+      for i in xrange(0, parallel_device_count):
+        with open(completion_files[i].name) as f:
+          if i == exception_index:
+            self.assertEquals('', f.read())
+          else:
+            self.assertEquals('complete', f.read())
+    finally:
+      for f in completion_files:
+        os.remove(f.name)
+
+  def testReusable(self):
+    devices = [ParallelizerTestObject(True) for _ in xrange(0, 10)]
+    p = ParallelizerTestObject.parallel(devices)
+    results = p.doReturn(True).pGet(1)
+    self.assertTrue(all(results))
+    results = p.doReturn(True).pGet(1)
+    self.assertTrue(all(results))
+    with self.assertRaises(Exception):
+      results = p.doRaise(Exception('reusableTest')).pGet(1)
+
+  def testContained(self):
+    devices = [ParallelizerTestObject(i) for i in xrange(0, 10)]
+    results = (ParallelizerTestObject.parallel(devices).helper
+        .doReturnStringThing().pGet(1))
+    self.assertTrue(isinstance(results, list))
+    self.assertEquals(10, len(results))
+    for i in xrange(0, 10):
+      self.assertEquals(str(i), results[i])
+
+  def testGetItem(self):
+    devices = [ParallelizerTestObject(range(i, i+10)) for i in xrange(0, 10)]
+    results = ParallelizerTestObject.parallel(devices)[9].pGet(1)
+    self.assertEquals(range(9, 19), results)
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
+

android/pylib/utils/reraiser_thread.py

@@ -56,6 +56,7 @@ class ReraiserThread(threading.Thread):
     self._func = func
     self._args = args
     self._kwargs = kwargs
+    self._ret = None
     self._exc_info = None
 
   def ReraiseIfException(self):
@@ -63,11 +64,16 @@ class ReraiserThread(threading.Thread):
     if self._exc_info:
       raise self._exc_info[0], self._exc_info[1], self._exc_info[2]
 
+  def GetReturnValue(self):
+    """Reraise exception if present, otherwise get the return value."""
+    self.ReraiseIfException()
+    return self._ret
+
   #override
   def run(self):
     """Overrides Thread.run() to add support for reraising exceptions."""
     try:
-      self._func(*self._args, **self._kwargs)
+      self._ret = self._func(*self._args, **self._kwargs)
     except:
       self._exc_info = sys.exc_info()
       raise
@@ -138,3 +144,14 @@ class ReraiserThreadGroup(object):
       for thread in (t for t in self._threads if t.isAlive()):
         LogThreadStack(thread)
       raise
+
+  def GetAllReturnValues(self, watcher=watchdog_timer.WatchdogTimer(None)):
+    """Get all return values, joining all threads if necessary.
+
+    Args:
+      watcher: same as in |JoinAll|. Only used if threads are alive.
+    """
+    if any([t.isAlive() for t in self._threads]):
+      self.JoinAll(watcher)
+    return [t.GetReturnValue() for t in self._threads]
+