[Android] Remove chromium version of devil.

build/android/devil/utils/parallelizer.py

-# 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=protected-access
-
-from devil.utils import reraiser_thread
-from devil.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 = type(self)(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 = type(self)(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 = type(self)(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 pMap(self, f, *args, **kwargs):
-    """Map a function across the current wrapped objects in parallel.
-
-    This calls f(o, *args, **kwargs) for each o in the set of wrapped objects.
-
-    Note that this call is asynchronous. Call pFinish on the return value to
-    block until the call finishes.
-
-    Args:
-      f: The function to call.
-      args: The positional args to pass to f.
-      kwargs: The keyword args to pass to f.
-    Returns:
-      A Parallelizer wrapping the ReraiserThreadGroup running the map in
-      parallel.
-    """
-    self._assertNoShadow('pMap')
-    r = type(self)(self._orig_objs)
-    r._objs = reraiser_thread.ReraiserThreadGroup(
-        [reraiser_thread.ReraiserThread(
-            f, args=tuple([o] + list(args)), kwargs=kwargs,
-            name='%s(%s)' % (f.__name__, d))
-         for d, o in zip(self._orig_objs, self._objs)])
-    r._objs.StartAll() # pylint: disable=W0212
-    return r
-
-  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, attr_name)
-    else:
-      assert not any(hasattr(o, '_assertNoShadow') for o in self._objs)
-      assert not any(hasattr(o, attr_name) 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
-
-  #override
-  def pMap(self, f, *args, **kwargs):
-    """Map a function across the current wrapped objects in parallel.
-
-    This calls f(o, *args, **kwargs) for each o in the set of wrapped objects.
-
-    Note that this call is synchronous.
-
-    Args:
-      f: The function to call.
-      args: The positional args to pass to f.
-      kwargs: The keyword args to pass to f.
-    Returns:
-      A Parallelizer wrapping the ReraiserThreadGroup running the map in
-      parallel.
-    """
-    r = super(SyncParallelizer, self).pMap(f, *args, **kwargs)
-    r.pFinish(None)
-    return r
-