[Android] Parallelize provision_devices.py.

build/android/pylib/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.
 
@@ skipping 137 matching lines @@
       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)
+    for d, o in zip(self._orig_objs, self._objs):
+      # TODO(jbudorick): XXX REMOVE BEFORE COMMITTING

[jbudorick, 2014/08/15 17:41:47]

This will be gone in the next patchset, fwiw.

+      print '%s(%s)' % (f.__name__, d)
+    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'
@@ skipping 19 matching lines @@
     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
+