Remove the `tff.framework.set_default_executor` API.

* Removed the `tff.framework.set_default_executor` API.
* Updated the callers to use the higher-level convienent API `tff.backends.*` instead.

PiperOrigin-RevId: 321421612

tensorflow_federated/python/core/framework/BUILD

@@ -28,7 +28,6 @@ py_library(
         "//tensorflow_federated/python/core/impl/context_stack:get_context_stack",
         "//tensorflow_federated/python/core/impl/context_stack:set_default_context",
         "//tensorflow_federated/python/core/impl/executors:caching_executor",
-        "//tensorflow_federated/python/core/impl/executors:default_executor",
         "//tensorflow_federated/python/core/impl/executors:eager_tf_executor",
         "//tensorflow_federated/python/core/impl/executors:execution_context",
         "//tensorflow_federated/python/core/impl/executors:executor_base",

tensorflow_federated/python/core/framework/__init__.py

@@ -53,7 +53,6 @@ from tensorflow_federated.python.core.impl.context_stack.context_stack_base impo
 from tensorflow_federated.python.core.impl.context_stack.get_context_stack import get_context_stack
 from tensorflow_federated.python.core.impl.context_stack.set_default_context import set_default_context
 from tensorflow_federated.python.core.impl.executors.caching_executor import CachingExecutor
-from tensorflow_federated.python.core.impl.executors.default_executor import set_default_executor
 from tensorflow_federated.python.core.impl.executors.eager_tf_executor import EagerTFExecutor
 from tensorflow_federated.python.core.impl.executors.execution_context import ExecutionContext
 from tensorflow_federated.python.core.impl.executors.executor_base import Executor

tensorflow_federated/python/core/impl/executors/default_executor.py

@@ -13,38 +13,11 @@
 # limitations under the License.
 """Utilities to interact with the default executor."""
 
-from tensorflow_federated.python.core.impl import reference_executor
 from tensorflow_federated.python.core.impl.context_stack import context_stack_impl
 from tensorflow_federated.python.core.impl.executors import execution_context
-from tensorflow_federated.python.core.impl.executors import executor_factory
 from tensorflow_federated.python.core.impl.executors import executor_stacks
 
 
-def set_default_executor(executor_factory_instance):
-  """Places an `executor`-backed execution context at the top of the stack.
-
-  Note: This function is deprecated, please use
-  `tff.framework.set_default_context` instead.
-
-  Args:
-    executor_factory_instance: An instance of
-      `executor_factory.ExecutorFactory`.
-  """
-  if isinstance(executor_factory_instance, executor_factory.ExecutorFactory):
-    context = execution_context.ExecutionContext(executor_factory_instance)
-  elif isinstance(executor_factory_instance,
-                  reference_executor.ReferenceExecutor):
-    # TODO(b/148233458): ReferenceExecutor inherits from ExectionContext and is
-    # used as-is here. The plan is to migrate it to the new Executor base class
-    # and stand it up inside a factory like all other executors.
-    context = executor_factory_instance
-  else:
-    raise TypeError('Expected `executor_factory_instance` to be of type '
-                    '`executor_factory.ExecutorFactory`, found {}.'.format(
-                        type(executor_factory_instance)))
-  context_stack_impl.context_stack.set_default_context(context)
-
-
 def initialize_default_execution_context():
   factory = executor_stacks.local_executor_factory()
   context = execution_context.ExecutionContext(factory)

tensorflow_federated/python/core/impl/executors/default_executor_test.py

@@ -14,50 +14,10 @@
 
 from absl.testing import absltest
 
-from tensorflow_federated.python.core.impl import reference_executor
 from tensorflow_federated.python.core.impl.context_stack import context_stack_impl
 from tensorflow_federated.python.core.impl.context_stack import context_stack_test_utils
 from tensorflow_federated.python.core.impl.executors import default_executor
 from tensorflow_federated.python.core.impl.executors import execution_context
-from tensorflow_federated.python.core.impl.executors import executor_factory
-
-
-class TestSetDefaultExecutor(absltest.TestCase):
-
-  def setUp(self):
-    super().setUp()
-    context = context_stack_test_utils.TestContext()
-    context_stack_impl.context_stack.set_default_context(context)
-
-  def test_with_executor_factory(self):
-    context_stack = context_stack_impl.context_stack
-    executor_factory_impl = executor_factory.ExecutorFactoryImpl(lambda _: None)
-    self.assertNotIsInstance(context_stack.current,
-                             execution_context.ExecutionContext)
-
-    default_executor.set_default_executor(executor_factory_impl)
-
-    self.assertIsInstance(context_stack.current,
-                          execution_context.ExecutionContext)
-    self.assertIs(context_stack.current._executor_factory,
-                  executor_factory_impl)
-
-  # TODO(b/148233458): ReferenceExecutor is special cased by the implementation
-  # of `set_default_executor.set_default_executor`. This test exists to ensure
-  # that this case is handled well, but can be removed when that special casing
-  # is removed.
-  def test_with_reference_executor(self):
-    context_stack = context_stack_impl.context_stack
-    executor = reference_executor.ReferenceExecutor()
-    self.assertIsNot(context_stack.current, executor)
-
-    default_executor.set_default_executor(executor)
-
-    self.assertIs(context_stack.current, executor)
-
-  def test_raises_type_error_with_none(self):
-    with self.assertRaises(TypeError):
-      default_executor.set_default_executor(None)
 
 
 class TestInitializeDefaultExecutionContext(absltest.TestCase):