text: # Copyright 2020 The TensorFlow Authors. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # ==============================================================================
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  from tensorflow.python.distribute import device_util
  from tensorflow.python.distribute import packed_distributed_variable
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import config
  from tensorflow.python.framework import ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import resource_variable_ops
  from tensorflow.python.platform import test
  
  
  class PackedDistributedVariableTest(test.TestCase):
  
    def setUp(self):
      super(PackedDistributedVariableTest, self).setUp()
      cpus = config.list_physical_devices('CPU')
      # Set 2 virtual CPUs
      config.set_logical_device_configuration(cpus[0], [
          context.LogicalDeviceConfiguration(),
          context.LogicalDeviceConfiguration(),
      ])
  
    def testPackedVariable(self):
      with ops.device('/cpu:0'):
        v0 = resource_variable_ops.ResourceVariable(1.0, name='var0')
      with ops.device('/cpu:1'):
        v1 = resource_variable_ops.ResourceVariable(2.0, name='var1')
  
      packed_var = packed_distributed_variable.PackedDistributedVariable([v0, v1])
      self.assertTrue(packed_var.handle.is_packed)
      self.assertTrue(packed_var.is_initialized)
  
      with ops.device('/cpu:0'):
        self.assertAllEqual(packed_var.get_var_on_current_device(), v0)
        val0 = packed_var.assign(2.0).assign_add(1.0)
        self.assertAllEqual(val0, 3.0)
  
      with ops.device('/cpu:1'):
        self.assertAllEqual(packed_var.get_var_on_current_device(), v1)
        val0 = packed_var.assign(2.0).assign_add(1.0)
        self.assertAllEqual(val0, 3.0)
  
      @def_function.function
      def update_var():
        with ops.device('/cpu:0'):
          packed_var.assign_add(3.0).assign_sub(1.0)
          read0 = packed_var.value()
        with ops.device('/cpu:1'):
          packed_var.assign_sub(4.0).assign_sub(2.0)
          read1 = packed_var.value()
  
        return read0, read1
  
      self.assertAllEqual(update_var(), (5.0, -3.0))
  
    def testPackedVarAndDevice(self):
      device0 = device_util.canonicalize('/cpu:0')
      device1 = device_util.canonicalize('/cpu:1')
  
      with ops.device(device0):
        v0 = resource_variable_ops.ResourceVariable(1.0)
      with ops.device(device1):
        v1 = resource_variable_ops.ResourceVariable(2.0)
  
      packed_var = packed_distributed_variable.PackedDistributedVariable([v0, v1])
  
      packed_var0 = packed_distributed_variable.PackedVarAndDevice(
          packed_var, device0)
      self.assertTrue(packed_var0.handle.is_packed)
      self.assertAllEqual(math_ops.mul(packed_var0, 2.0), 2.0)
  
      packed_var1 = packed_distributed_variable.PackedVarAndDevice(
          packed_var, device1)
      self.assertAllEqual(packed_var1.assign(3.0), 3.0)
  
      @def_function.function
      def func():
        var0 = packed_distributed_variable.PackedVarAndDevice(packed_var, device0)
        var0.assign_add(3.0)
        var1 = packed_distributed_variable.PackedVarAndDevice(packed_var, device1)
        return var0.value(), math_ops.add(var1, 2.0)
  
      self.assertAllEqual(func(), (4.0, 5.0))
  
  
  if __name__ == '__main__':
    ops.enable_eager_execution()
    test.main()
  