Merge pull request #668 from nathanielmanistaatgoogle/assembly

The framework.assembly package.

14 files changed, 1290 insertions, 18 deletions

diff --git a/src/python/src/grpc/_adapter/_face_test_case.py b/src/python/src/grpc/_adapter/_face_test_case.py
index da73366f44..8cce322d30 100644
--- a/src/python/src/grpc/_adapter/_face_test_case.py
+++ b/src/python/src/grpc/_adapter/_face_test_case.py
@@ -81,7 +81,8 @@ class FaceTestCase(test_case.FaceTestCase, coverage.BlockingCoverage):
     fore_link = fore.ForeLink(
         pool, serialization.request_deserializers,
         serialization.response_serializers, None, ())
-    port = fore_link.start()
+    fore_link.start()
+    port = fore_link.port()
     rear_link = rear.RearLink(
         'localhost', port, pool,
         serialization.request_serializers, serialization.response_deserializers)
diff --git a/src/python/src/grpc/_adapter/_links_test.py b/src/python/src/grpc/_adapter/_links_test.py
index ba7660bb92..6b3bcee9fa 100644
--- a/src/python/src/grpc/_adapter/_links_test.py
+++ b/src/python/src/grpc/_adapter/_links_test.py
@@ -70,7 +70,8 @@ class RoundTripTest(unittest.TestCase):
         self.fore_link_pool, {test_method: None}, {test_method: None}, None, ())
     fore_link.join_rear_link(test_rear_link)
     test_rear_link.join_fore_link(fore_link)
-    port = fore_link.start()
+    fore_link.start()
+    port = fore_link.port()
 
     rear_link = rear.RearLink(
         'localhost', port, self.rear_link_pool, {test_method: None},
@@ -123,7 +124,8 @@ class RoundTripTest(unittest.TestCase):
         {test_method: _IDENTITY}, None, ())
     fore_link.join_rear_link(test_rear_link)
     test_rear_link.join_fore_link(fore_link)
-    port = fore_link.start()
+    fore_link.start()
+    port = fore_link.port()
 
     rear_link = rear.RearLink(
         'localhost', port, self.rear_link_pool, {test_method: _IDENTITY},
@@ -185,7 +187,8 @@ class RoundTripTest(unittest.TestCase):
         {test_method: scenario.serialize_response}, None, ())
     fore_link.join_rear_link(test_rear_link)
     test_rear_link.join_fore_link(fore_link)
-    port = fore_link.start()
+    fore_link.start()
+    port = fore_link.port()
 
     rear_link = rear.RearLink(
         'localhost', port, self.rear_link_pool,
diff --git a/src/python/src/grpc/_adapter/fore.py b/src/python/src/grpc/_adapter/fore.py
index f72b2fd5a5..051fc083f1 100644
--- a/src/python/src/grpc/_adapter/fore.py
+++ b/src/python/src/grpc/_adapter/fore.py
@@ -40,6 +40,7 @@ from grpc.framework.base import interfaces
 from grpc.framework.base.packets import interfaces as ticket_interfaces
 from grpc.framework.base.packets import null
 from grpc.framework.base.packets import packets as tickets
+from grpc.framework.foundation import activated
 
 
 @enum.unique
@@ -65,7 +66,7 @@ def _status(call, rpc_state):
   rpc_state.write.low = _LowWrite.CLOSED
 
 
-class ForeLink(ticket_interfaces.ForeLink):
+class ForeLink(ticket_interfaces.ForeLink, activated.Activated):
   """A service-side bridge between RPC Framework and the C-ish _low code."""
 
   def __init__(
@@ -92,13 +93,14 @@ class ForeLink(ticket_interfaces.ForeLink):
     self._response_serializers = response_serializers
     self._root_certificates = root_certificates
     self._key_chain_pairs = key_chain_pairs
-    self._port = port
+    self._requested_port = port
 
     self._rear_link = null.NULL_REAR_LINK
     self._completion_queue = None
     self._server = None
     self._rpc_states = {}
     self._spinning = False
+    self._port = None
 
   def _on_stop_event(self):
     self._spinning = False
@@ -264,23 +266,24 @@ class ForeLink(ticket_interfaces.ForeLink):
     """See ticket_interfaces.ForeLink.join_rear_link for specification."""
     self._rear_link = null.NULL_REAR_LINK if rear_link is None else rear_link
 
-  def start(self):
+  def _start(self):
     """Starts this ForeLink.
 
     This method must be called before attempting to exchange tickets with this
     object.
     """
     with self._condition:
-      address = '[::]:%d' % (0 if self._port is None else self._port)
+      address = '[::]:%d' % (
+          0 if self._requested_port is None else self._requested_port)
       self._completion_queue = _low.CompletionQueue()
       if self._root_certificates is None and not self._key_chain_pairs:
         self._server = _low.Server(self._completion_queue, None)
-        port = self._server.add_http2_addr(address)
+        self._port = self._server.add_http2_addr(address)
       else:
         server_credentials = _low.ServerCredentials(
           self._root_certificates, self._key_chain_pairs)
         self._server = _low.Server(self._completion_queue, server_credentials)
-        port = self._server.add_secure_http2_addr(address)
+        self._port = self._server.add_secure_http2_addr(address)
       self._server.start()
 
       self._server.service(None)
@@ -288,11 +291,11 @@ class ForeLink(ticket_interfaces.ForeLink):
       self._pool.submit(self._spin, self._completion_queue, self._server)
       self._spinning = True
 
-      return port
+      return self
 
   # TODO(nathaniel): Expose graceful-shutdown semantics in which this object
   # enters a state in which it finishes ongoing RPCs but refuses new ones.
-  def stop(self):
+  def _stop(self):
     """Stops this ForeLink.
 
     This method must be called for proper termination of this object, and no
@@ -301,7 +304,7 @@ class ForeLink(ticket_interfaces.ForeLink):
     """
     with self._condition:
       self._server.stop()
-      # TODO(b/18904187): Yep, this is weird. Deleting a server shouldn't have a
+      # TODO(nathaniel): Yep, this is weird. Deleting a server shouldn't have a
       # behaviorally significant side-effect.
       self._server = None
       self._completion_queue.stop()
@@ -309,6 +312,35 @@ class ForeLink(ticket_interfaces.ForeLink):
       while self._spinning:
         self._condition.wait()
 
+      self._port = None
+
+  def __enter__(self):
+    """See activated.Activated.__enter__ for specification."""
+    return self._start()
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    """See activated.Activated.__exit__ for specification."""
+    self._stop()
+    return False
+
+  def start(self):
+    """See activated.Activated.start for specification."""
+    return self._start()
+
+  def stop(self):
+    """See activated.Activated.stop for specification."""
+    self._stop()
+
+  def port(self):
+    """Identifies the port on which this ForeLink is servicing RPCs.
+
+    Returns:
+      The number of the port on which this ForeLink is servicing RPCs, or None
+        if this ForeLink is not currently activated and servicing RPCs.
+    """
+    with self._condition:
+      return self._port
+
   def accept_back_to_front_ticket(self, ticket):
     """See ticket_interfaces.ForeLink.accept_back_to_front_ticket for spec."""
     with self._condition:
diff --git a/src/python/src/grpc/_adapter/rear.py b/src/python/src/grpc/_adapter/rear.py
index c47c0aa020..cbcf121d9a 100644
--- a/src/python/src/grpc/_adapter/rear.py
+++ b/src/python/src/grpc/_adapter/rear.py
@@ -39,6 +39,7 @@ from grpc._adapter import _low
 from grpc.framework.base.packets import interfaces as ticket_interfaces
 from grpc.framework.base.packets import null
 from grpc.framework.base.packets import packets as tickets
+from grpc.framework.foundation import activated
 
 _INVOCATION_EVENT_KINDS = (
     _low.Event.Kind.METADATA_ACCEPTED,
@@ -84,7 +85,7 @@ def _write(operation_id, call, outstanding, write_state, serialized_payload):
     raise ValueError('Write attempted after writes completed!')
 
 
-class RearLink(ticket_interfaces.RearLink):
+class RearLink(ticket_interfaces.RearLink, activated.Activated):
   """An invocation-side bridge between RPC Framework and the C-ish _low code."""
 
   def __init__(
@@ -297,7 +298,7 @@ class RearLink(ticket_interfaces.RearLink):
     with self._condition:
       self._fore_link = null.NULL_FORE_LINK if fore_link is None else fore_link
 
-  def start(self):
+  def _start(self):
     """Starts this RearLink.
 
     This method must be called before attempting to exchange tickets with this
@@ -306,8 +307,9 @@ class RearLink(ticket_interfaces.RearLink):
     with self._condition:
       self._completion_queue = _low.CompletionQueue()
       self._channel = _low.Channel('%s:%d' % (self._host, self._port))
+    return self
 
-  def stop(self):
+  def _stop(self):
     """Stops this RearLink.
 
     This method must be called for proper termination of this object, and no
@@ -321,6 +323,23 @@ class RearLink(ticket_interfaces.RearLink):
       while self._spinning:
         self._condition.wait()
 
+  def __enter__(self):
+    """See activated.Activated.__enter__ for specification."""
+    return self._start()
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    """See activated.Activated.__exit__ for specification."""
+    self._stop()
+    return False
+
+  def start(self):
+    """See activated.Activated.start for specification."""
+    return self._start()
+
+  def stop(self):
+    """See activated.Activated.stop for specification."""
+    self._stop()
+
   def accept_front_to_back_ticket(self, ticket):
     """See ticket_interfaces.RearLink.accept_front_to_back_ticket for spec."""
     with self._condition:
diff --git a/src/python/src/grpc/early_adopter/implementations.py b/src/python/src/grpc/early_adopter/implementations.py
index c549317d15..1d76d0f9e0 100644
--- a/src/python/src/grpc/early_adopter/implementations.py
+++ b/src/python/src/grpc/early_adopter/implementations.py
@@ -70,7 +70,8 @@ class _Server(interfaces.Server):
             self._pool, self._breakdown.request_deserializers,
             self._breakdown.response_serializers, None,
             ((self._private_key, self._certificate_chain),), port=self._port)
-        port = self._fore_link.start()
+        self._fore_link.start()
+        port = self._fore_link.port()
         self._back = _tickets_implementations.back(
             servicer, self._pool, self._pool, self._pool, _MEGA_TIMEOUT,
             _MEGA_TIMEOUT)
diff --git a/src/python/src/grpc/framework/assembly/__init__.py b/src/python/src/grpc/framework/assembly/__init__.py
new file mode 100644
index 0000000000..7086519106
--- /dev/null
+++ b/src/python/src/grpc/framework/assembly/__init__.py
@@ -0,0 +1,30 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
diff --git a/src/python/src/grpc/framework/assembly/implementations.py b/src/python/src/grpc/framework/assembly/implementations.py
new file mode 100644
index 0000000000..461aa9c855
--- /dev/null
+++ b/src/python/src/grpc/framework/assembly/implementations.py
@@ -0,0 +1,305 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Implementations for assembling RPC framework values."""
+
+import threading
+
+from grpc.framework.assembly import interfaces
+from grpc.framework.base import util as base_utilities
+from grpc.framework.base.packets import implementations as tickets_implementations
+from grpc.framework.base.packets import interfaces as tickets_interfaces
+from grpc.framework.common import cardinality
+from grpc.framework.common import style
+from grpc.framework.face import implementations as face_implementations
+from grpc.framework.face import interfaces as face_interfaces
+from grpc.framework.face import utilities as face_utilities
+from grpc.framework.foundation import activated
+from grpc.framework.foundation import logging_pool
+
+_ONE_DAY_IN_SECONDS = 60 * 60 * 24
+_THREAD_POOL_SIZE = 100
+
+
+class _FaceStub(object):
+
+  def __init__(self, rear_link):
+    self._rear_link = rear_link
+    self._lock = threading.Lock()
+    self._pool = None
+    self._front = None
+    self._under_stub = None
+
+  def __enter__(self):
+    with self._lock:
+      self._pool = logging_pool.pool(_THREAD_POOL_SIZE)
+      self._front = tickets_implementations.front(
+          self._pool, self._pool, self._pool)
+      self._rear_link.start()
+      self._rear_link.join_fore_link(self._front)
+      self._front.join_rear_link(self._rear_link)
+      self._under_stub = face_implementations.stub(self._front, self._pool)
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    with self._lock:
+      self._under_stub = None
+      self._rear_link.stop()
+      base_utilities.wait_for_idle(self._front)
+      self._front = None
+      self._pool.shutdown(wait=True)
+      self._pool = None
+    return False
+
+  def __getattr__(self, attr):
+    with self._lock:
+      if self._under_stub is None:
+        raise ValueError('Called out of context!')
+      else:
+        return getattr(self._under_stub, attr)
+
+
+def _behaviors(implementations, front, pool):
+  behaviors = {}
+  stub = face_implementations.stub(front, pool)
+  for name, implementation in implementations.iteritems():
+    if implementation.cardinality is cardinality.Cardinality.UNARY_UNARY:
+      behaviors[name] = stub.unary_unary_sync_async(name)
+    elif implementation.cardinality is cardinality.Cardinality.UNARY_STREAM:
+      behaviors[name] = lambda request, context, bound_name=name: (
+          stub.inline_value_in_stream_out(bound_name, request, context))
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_UNARY:
+      behaviors[name] = stub.stream_unary_sync_async(name)
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_STREAM:
+      behaviors[name] = lambda request_iterator, context, bound_name=name: (
+          stub.inline_stream_in_stream_out(
+              bound_name, request_iterator, context))
+  return behaviors
+
+
+class _DynamicInlineStub(object):
+
+  def __init__(self, implementations, rear_link):
+    self._implementations = implementations
+    self._rear_link = rear_link
+    self._lock = threading.Lock()
+    self._pool = None
+    self._front = None
+    self._behaviors = None
+
+  def __enter__(self):
+    with self._lock:
+      self._pool = logging_pool.pool(_THREAD_POOL_SIZE)
+      self._front = tickets_implementations.front(
+          self._pool, self._pool, self._pool)
+      self._rear_link.start()
+      self._rear_link.join_fore_link(self._front)
+      self._front.join_rear_link(self._rear_link)
+      self._behaviors = _behaviors(
+          self._implementations, self._front, self._pool)
+      return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    with self._lock:
+      self._behaviors = None
+      self._rear_link.stop()
+      base_utilities.wait_for_idle(self._front)
+      self._front = None
+      self._pool.shutdown(wait=True)
+      self._pool = None
+    return False
+
+  def __getattr__(self, attr):
+    with self._lock:
+      behavior = self._behaviors.get(attr)
+      if behavior is None:
+        raise AttributeError(attr)
+      else:
+        return behavior
+
+
+def _servicer(implementations, pool):
+  inline_value_in_value_out_methods = {}
+  inline_value_in_stream_out_methods = {}
+  inline_stream_in_value_out_methods = {}
+  inline_stream_in_stream_out_methods = {}
+  event_value_in_value_out_methods = {}
+  event_value_in_stream_out_methods = {}
+  event_stream_in_value_out_methods = {}
+  event_stream_in_stream_out_methods = {}
+
+  for name, implementation in implementations.iteritems():
+    if implementation.cardinality is cardinality.Cardinality.UNARY_UNARY:
+      if implementation.style is style.Service.INLINE:
+        inline_value_in_value_out_methods[name] = (
+            face_utilities.inline_unary_unary_method(implementation.unary_unary_inline))
+      elif implementation.style is style.Service.EVENT:
+        event_value_in_value_out_methods[name] = (
+            face_utilities.event_unary_unary_method(implementation.unary_unary_event))
+    elif implementation.cardinality is cardinality.Cardinality.UNARY_STREAM:
+      if implementation.style is style.Service.INLINE:
+        inline_value_in_stream_out_methods[name] = (
+            face_utilities.inline_unary_stream_method(implementation.unary_stream_inline))
+      elif implementation.style is style.Service.EVENT:
+        event_value_in_stream_out_methods[name] = (
+            face_utilities.event_unary_stream_method(implementation.unary_stream_event))
+    if implementation.cardinality is cardinality.Cardinality.STREAM_UNARY:
+      if implementation.style is style.Service.INLINE:
+        inline_stream_in_value_out_methods[name] = (
+            face_utilities.inline_stream_unary_method(implementation.stream_unary_inline))
+      elif implementation.style is style.Service.EVENT:
+        event_stream_in_value_out_methods[name] = (
+            face_utilities.event_stream_unary_method(implementation.stream_unary_event))
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_STREAM:
+      if implementation.style is style.Service.INLINE:
+        inline_stream_in_stream_out_methods[name] = (
+            face_utilities.inline_stream_stream_method(implementation.stream_stream_inline))
+      elif implementation.style is style.Service.EVENT:
+        event_stream_in_stream_out_methods[name] = (
+            face_utilities.event_stream_stream_method(implementation.stream_stream_event))
+
+  return face_implementations.servicer(
+      pool,
+      inline_value_in_value_out_methods=inline_value_in_value_out_methods,
+      inline_value_in_stream_out_methods=inline_value_in_stream_out_methods,
+      inline_stream_in_value_out_methods=inline_stream_in_value_out_methods,
+      inline_stream_in_stream_out_methods=inline_stream_in_stream_out_methods,
+      event_value_in_value_out_methods=event_value_in_value_out_methods,
+      event_value_in_stream_out_methods=event_value_in_stream_out_methods,
+      event_stream_in_value_out_methods=event_stream_in_value_out_methods,
+      event_stream_in_stream_out_methods=event_stream_in_stream_out_methods)
+
+
+class _ServiceAssembly(activated.Activated):
+
+  def __init__(self, implementations, fore_link):
+    self._implementations = implementations
+    self._fore_link = fore_link
+    self._lock = threading.Lock()
+    self._pool = None
+    self._back = None
+
+  def _start(self):
+    with self._lock:
+      self._pool = logging_pool.pool(_THREAD_POOL_SIZE)
+      servicer = _servicer(self._implementations, self._pool)
+      self._back = tickets_implementations.back(
+          servicer, self._pool, self._pool, self._pool, _ONE_DAY_IN_SECONDS,
+          _ONE_DAY_IN_SECONDS)
+      self._fore_link.start()
+      self._fore_link.join_rear_link(self._back)
+      self._back.join_fore_link(self._fore_link)
+
+  def _stop(self):
+    with self._lock:
+      self._fore_link.stop()
+      base_utilities.wait_for_idle(self._back)
+      self._back = None
+      self._pool.shutdown(wait=True)
+      self._pool = None
+
+  def __enter__(self):
+    self._start()
+    return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    self._stop()
+    return False
+
+  def start(self):
+    return self._start()
+
+  def stop(self):
+    self._stop()
+
+
+def assemble_face_stub(activated_rear_link):
+  """Assembles a face_interfaces.Stub.
+
+  The returned object is a context manager and may only be used in context to
+  invoke RPCs.
+
+  Args:
+    activated_rear_link: An object that is both a tickets_interfaces.RearLink
+      and an activated.Activated. The object should be in the inactive state
+      when passed to this method.
+
+  Returns:
+    A face_interfaces.Stub on which, in context, RPCs can be invoked.
+  """
+  return _FaceStub(activated_rear_link)
+
+
+def assemble_dynamic_inline_stub(implementations, activated_rear_link):
+  """Assembles a stub with method names for attributes.
+
+  The returned object is a context manager and may only be used in context to
+  invoke RPCs.
+
+  The returned object, when used in context, will respond to attribute access
+  as follows: if the requested attribute is the name of a unary-unary RPC
+  method, the value of the attribute will be a
+  face_interfaces.UnaryUnarySyncAsync with which to invoke the RPC method. If
+  the requested attribute is the name of a unary-stream RPC method, the value
+  of the attribute will be a callable with the semantics of
+  face_interfaces.Stub.inline_value_in_stream_out, minus the "name" parameter,
+  with which to invoke the RPC method. If the requested attribute is the name
+  of a stream-unary RPC method, the value of the attribute will be a
+  face_interfaces.StreamUnarySyncAsync with which to invoke the RPC method. If
+  the requested attribute is the name of a stream-stream RPC method, the value
+  of the attribute will be a callable with the semantics of
+  face_interfaces.Stub.inline_stream_in_stream_out, minus the "name" parameter,
+  with which to invoke the RPC method.
+
+  Args:
+    implementations: A dictionary from RPC method name to
+      interfaces.MethodImplementation.
+    activated_rear_link: An object that is both a tickets_interfaces.RearLink
+      and an activated.Activated. The object should be in the inactive state
+      when passed to this method.
+
+  Returns:
+    A stub on which, in context, RPCs can be invoked.
+  """
+  return _DynamicInlineStub(implementations, activated_rear_link)
+
+
+def assemble_service(implementations, activated_fore_link):
+  """Assembles the service-side of the RPC Framework stack.
+
+  Args:
+    implementations: A dictionary from RPC method name to
+      interfaces.MethodImplementation.
+    activated_fore_link: An object that is both a tickets_interfaces.ForeLink
+      and an activated.Activated. The object should be in the inactive state
+      when passed to this method.
+
+  Returns:
+    An activated.Activated value encapsulating RPC service.
+  """
+  return _ServiceAssembly(implementations, activated_fore_link)
diff --git a/src/python/src/grpc/framework/assembly/implementations_test.py b/src/python/src/grpc/framework/assembly/implementations_test.py
new file mode 100644
index 0000000000..74dc02ed83
--- /dev/null
+++ b/src/python/src/grpc/framework/assembly/implementations_test.py
@@ -0,0 +1,284 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# TODO(nathaniel): Expand this test coverage.
+
+"""Test of the GRPC-backed ForeLink and RearLink."""
+
+import threading
+import unittest
+
+from grpc.framework.assembly import implementations
+from grpc.framework.assembly import utilities
+from grpc.framework.base import interfaces
+from grpc.framework.base.packets import packets as tickets
+from grpc.framework.base.packets import interfaces as tickets_interfaces
+from grpc.framework.base.packets import null
+from grpc.framework.foundation import logging_pool
+from grpc._junkdrawer import math_pb2
+
+DIV = 'Div'
+DIV_MANY = 'DivMany'
+FIB = 'Fib'
+SUM = 'Sum'
+
+def _fibbonacci(limit):
+  left, right = 0, 1
+  for _ in xrange(limit):
+    yield left
+    left, right = right, left + right
+
+
+def _div(request, unused_context):
+  return math_pb2.DivReply(
+      quotient=request.dividend / request.divisor,
+      remainder=request.dividend % request.divisor)
+
+
+def _div_many(request_iterator, unused_context):
+  for request in request_iterator:
+    yield math_pb2.DivReply(
+        quotient=request.dividend / request.divisor,
+        remainder=request.dividend % request.divisor)
+
+
+def _fib(request, unused_context):
+  for number in _fibbonacci(request.limit):
+    yield math_pb2.Num(num=number)
+
+
+def _sum(request_iterator, unused_context):
+  accumulation = 0
+  for request in request_iterator:
+    accumulation += request.num
+  return math_pb2.Num(num=accumulation)
+
+
+_IMPLEMENTATIONS = {
+    DIV: utilities.unary_unary_inline(_div),
+    DIV_MANY: utilities.stream_stream_inline(_div_many),
+    FIB: utilities.unary_stream_inline(_fib),
+    SUM: utilities.stream_unary_inline(_sum),
+}
+
+_TIMEOUT = 10
+
+
+class PipeLink(tickets_interfaces.ForeLink, tickets_interfaces.RearLink):
+
+  def __init__(self):
+    self._fore_lock = threading.Lock()
+    self._fore_link = null.NULL_FORE_LINK
+    self._rear_lock = threading.Lock()
+    self._rear_link = null.NULL_REAR_LINK
+
+  def __enter__(self):
+    return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    return False
+
+  def start(self):
+    pass
+
+  def stop(self):
+    pass
+
+  def accept_back_to_front_ticket(self, ticket):
+    with self._fore_lock:
+      self._fore_link.accept_back_to_front_ticket(ticket)
+
+  def join_rear_link(self, rear_link):
+    with self._rear_lock:
+      self._rear_link = null.NULL_REAR_LINK if rear_link is None else rear_link
+
+  def accept_front_to_back_ticket(self, ticket):
+    with self._rear_lock:
+      self._rear_link.accept_front_to_back_ticket(ticket)
+
+  def join_fore_link(self, fore_link):
+    with self._fore_lock:
+      self._fore_link = null.NULL_FORE_LINK if fore_link is None else fore_link
+
+
+class FaceStubTest(unittest.TestCase):
+
+  def testUnaryUnary(self):
+    divisor = 7
+    dividend = 13
+    expected_quotient = 1
+    expected_remainder = 6
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    face_stub = implementations.assemble_face_stub(pipe)
+
+    service.start()
+    try:
+      with face_stub:
+        response = face_stub.blocking_value_in_value_out(
+            DIV, math_pb2.DivArgs(divisor=divisor, dividend=dividend),
+            _TIMEOUT)
+        self.assertEqual(expected_quotient, response.quotient)
+        self.assertEqual(expected_remainder, response.remainder)
+    finally:
+      service.stop()
+
+  def testUnaryStream(self):
+    stream_length = 29
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    face_stub = implementations.assemble_face_stub(pipe)
+
+    with service, face_stub:
+      responses = list(
+          face_stub.inline_value_in_stream_out(
+              FIB, math_pb2.FibArgs(limit=stream_length), _TIMEOUT))
+      numbers = [response.num for response in responses]
+      for early, middle, later in zip(numbers, numbers[1:], numbers[2:]):
+        self.assertEqual(early + middle, later)
+
+  def testStreamUnary(self):
+    stream_length = 13
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    face_stub = implementations.assemble_face_stub(pipe)
+
+    with service, face_stub:
+      sync_async = face_stub.stream_unary_sync_async(SUM)
+      response_future = sync_async.async(
+          (math_pb2.Num(num=index) for index in range(stream_length)),
+          _TIMEOUT)
+      self.assertEqual(
+          (stream_length * (stream_length - 1)) / 2,
+          response_future.result().num)
+
+  def testStreamStream(self):
+    stream_length = 17
+    divisor_offset = 7
+    dividend_offset = 17
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    face_stub = implementations.assemble_face_stub(pipe)
+
+    with service, face_stub:
+      response_iterator = face_stub.inline_stream_in_stream_out(
+          DIV_MANY,
+          (math_pb2.DivArgs(
+               divisor=divisor_offset + index,
+               dividend=dividend_offset + index)
+           for index in range(stream_length)),
+          _TIMEOUT)
+      for index, response in enumerate(response_iterator):
+        self.assertEqual(
+            (dividend_offset + index) / (divisor_offset + index),
+            response.quotient)
+        self.assertEqual(
+            (dividend_offset + index) % (divisor_offset + index),
+            response.remainder)
+      self.assertEqual(stream_length, index + 1)
+
+
+class DynamicInlineStubTest(unittest.TestCase):
+
+  def testUnaryUnary(self):
+    divisor = 59
+    dividend = 973
+    expected_quotient = dividend / divisor
+    expected_remainder = dividend % divisor
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    dynamic_stub = implementations.assemble_dynamic_inline_stub(
+        _IMPLEMENTATIONS, pipe)
+
+    service.start()
+    with dynamic_stub:
+      response = dynamic_stub.Div(
+          math_pb2.DivArgs(divisor=divisor, dividend=dividend), _TIMEOUT)
+      self.assertEqual(expected_quotient, response.quotient)
+      self.assertEqual(expected_remainder, response.remainder)
+    service.stop()
+
+  def testUnaryStream(self):
+    stream_length = 43
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    dynamic_stub = implementations.assemble_dynamic_inline_stub(
+        _IMPLEMENTATIONS, pipe)
+
+    with service, dynamic_stub:
+      response_iterator = dynamic_stub.Fib(
+          math_pb2.FibArgs(limit=stream_length), _TIMEOUT)
+      numbers = tuple(response.num for response in response_iterator)
+      for early, middle, later in zip(numbers, numbers[:1], numbers[:2]):
+        self.assertEqual(early + middle, later)
+      self.assertEqual(stream_length, len(numbers))
+
+  def testStreamUnary(self):
+    stream_length = 127
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    dynamic_stub = implementations.assemble_dynamic_inline_stub(
+        _IMPLEMENTATIONS, pipe)
+
+    with service, dynamic_stub:
+      response_future = dynamic_stub.Sum.async(
+          (math_pb2.Num(num=index) for index in range(stream_length)),
+          _TIMEOUT)
+      self.assertEqual(
+          (stream_length * (stream_length - 1)) / 2,
+          response_future.result().num)
+
+  def testStreamStream(self):
+    stream_length = 179
+    divisor_offset = 71
+    dividend_offset = 1763
+    pipe = PipeLink()
+    service = implementations.assemble_service(_IMPLEMENTATIONS, pipe)
+    dynamic_stub = implementations.assemble_dynamic_inline_stub(
+        _IMPLEMENTATIONS, pipe)
+
+    with service, dynamic_stub:
+      response_iterator = dynamic_stub.DivMany(
+          (math_pb2.DivArgs(
+               divisor=divisor_offset + index,
+               dividend=dividend_offset + index)
+           for index in range(stream_length)),
+          _TIMEOUT)
+      for index, response in enumerate(response_iterator):
+        self.assertEqual(
+            (dividend_offset + index) / (divisor_offset + index),
+            response.quotient)
+        self.assertEqual(
+            (dividend_offset + index) % (divisor_offset + index),
+            response.remainder)
+      self.assertEqual(stream_length, index + 1)
+
+
+if __name__ == '__main__':
+  unittest.main()
diff --git a/src/python/src/grpc/framework/assembly/interfaces.py b/src/python/src/grpc/framework/assembly/interfaces.py
new file mode 100644
index 0000000000..e5d750b2bc
--- /dev/null
+++ b/src/python/src/grpc/framework/assembly/interfaces.py
@@ -0,0 +1,91 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# TODO(nathaniel): The assembly layer only exists to smooth out wrinkles in
+# the face layer. The two should be squashed together as soon as manageable.
+"""Interfaces for assembling RPC Framework values."""
+
+import abc
+
+# cardinality, style, and stream are referenced from specification in this
+# module.
+from grpc.framework.common import cardinality  # pylint: disable=unused-import
+from grpc.framework.common import style  # pylint: disable=unused-import
+from grpc.framework.foundation import stream  # pylint: disable=unused-import
+
+
+class MethodImplementation(object):
+  """A sum type that describes an RPC method implementation.
+
+  Attributes:
+    cardinality: A cardinality.Cardinality value.
+    style: A style.Service value.
+    unary_unary_inline: The implementation of the RPC method as a callable
+      value that takes a request value and a face_interfaces.RpcContext object
+      and returns a response value. Only non-None if cardinality is
+      cardinality.Cardinality.UNARY_UNARY and style is style.Service.INLINE.
+    unary_stream_inline: The implementation of the RPC method as a callable
+      value that takes a request value and a face_interfaces.RpcContext object
+      and returns an iterator of response values. Only non-None if cardinality
+      is cardinality.Cardinality.UNARY_STREAM and style is
+      style.Service.INLINE.
+    stream_unary_inline: The implementation of the RPC method as a callable
+      value that takes an iterator of request values and a
+      face_interfaces.RpcContext object and returns a response value. Only
+      non-None if cardinality is cardinality.Cardinality.STREAM_UNARY and style
+      is style.Service.INLINE.
+    stream_stream_inline: The implementation of the RPC method as a callable
+      value that takes an iterator of request values and a
+      face_interfaces.RpcContext object and returns an iterator of response
+      values. Only non-None if cardinality is
+      cardinality.Cardinality.STREAM_STREAM and style is style.Service.INLINE.
+    unary_unary_event: The implementation of the RPC method as a callable value
+      that takes a request value, a response callback to which to pass the
+      response value of the RPC, and a face_interfaces.RpcContext. Only
+      non-None if cardinality is cardinality.Cardinality.UNARY_UNARY and style
+      is style.Service.EVENT.
+    unary_stream_event: The implementation of the RPC method as a callable
+      value that takes a request value, a stream.Consumer to which to pass the
+      the response values of the RPC, and a face_interfaces.RpcContext. Only
+      non-None if cardinality is cardinality.Cardinality.UNARY_STREAM and style
+      is style.Service.EVENT.
+    stream_unary_event: The implementation of the RPC method as a callable
+      value that takes a response callback to which to pass the response value
+      of the RPC and a face_interfaces.RpcContext and returns a stream.Consumer
+      to which the request values of the RPC should be passed. Only non-None if
+      cardinality is cardinality.Cardinality.STREAM_UNARY and style is
+      style.Service.EVENT.
+    stream_stream_event: The implementation of the RPC method as a callable
+      value that takes a stream.Consumer to which to pass the response values
+      of the RPC and a face_interfaces.RpcContext and returns a stream.Consumer
+      to which the request values of the RPC should be passed. Only non-None if
+      cardinality is cardinality.Cardinality.STREAM_STREAM and style is
+      style.Service.EVENT.
+  """
+  __metaclass__ = abc.ABCMeta
diff --git a/src/python/src/grpc/framework/assembly/utilities.py b/src/python/src/grpc/framework/assembly/utilities.py
new file mode 100644
index 0000000000..80e7f59c03
--- /dev/null
+++ b/src/python/src/grpc/framework/assembly/utilities.py
@@ -0,0 +1,179 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Utilities for assembling RPC framework values."""
+
+import collections
+
+from grpc.framework.assembly import interfaces
+from grpc.framework.common import cardinality
+from grpc.framework.common import style
+from grpc.framework.face import interfaces as face_interfaces
+from grpc.framework.foundation import stream
+
+
+class _MethodImplementation(
+    interfaces.MethodImplementation,
+    collections.namedtuple(
+        '_MethodImplementation',
+        ['cardinality', 'style', 'unary_unary_inline', 'unary_stream_inline',
+         'stream_unary_inline', 'stream_stream_inline', 'unary_unary_event',
+         'unary_stream_event', 'stream_unary_event', 'stream_stream_event',])):
+  pass
+
+
+def unary_unary_inline(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a unary-unary RPC method as a callable value
+      that takes a request value and a face_interfaces.RpcContext object and
+      returns a response value.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.UNARY_UNARY, style.Service.INLINE, behavior,
+      None, None, None, None, None, None, None)
+
+
+def unary_stream_inline(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a unary-stream RPC method as a callable
+      value that takes a request value and a face_interfaces.RpcContext object
+      and returns an iterator of response values.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.UNARY_STREAM, style.Service.INLINE, None,
+      behavior, None, None, None, None, None, None)
+
+
+def stream_unary_inline(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a stream-unary RPC method as a callable
+      value that takes an iterator of request values and a
+      face_interfaces.RpcContext object and returns a response value.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.STREAM_UNARY, style.Service.INLINE, None, None,
+      behavior, None, None, None, None, None)
+
+
+def stream_stream_inline(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a stream-stream RPC method as a callable
+      value that takes an iterator of request values and a
+      face_interfaces.RpcContext object and returns an iterator of response
+      values.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.STREAM_STREAM, style.Service.INLINE, None, None,
+      None, behavior, None, None, None, None)
+
+
+def unary_unary_event(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a unary-unary RPC method as a callable
+      value that takes a request value, a response callback to which to pass
+      the response value of the RPC, and a face_interfaces.RpcContext.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.UNARY_UNARY, style.Service.EVENT, None, None,
+      None, None, behavior, None, None, None)
+
+
+def unary_stream_event(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a unary-stream RPC method as a callable
+      value that takes a request value, a stream.Consumer to which to pass the
+      the response values of the RPC, and a face_interfaces.RpcContext.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.UNARY_STREAM, style.Service.EVENT, None, None,
+      None, None, None, behavior, None, None)
+
+
+def stream_unary_event(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a stream-unary RPC method as a callable
+      value that takes a response callback to which to pass the response value
+      of the RPC and a face_interfaces.RpcContext and returns a stream.Consumer
+      to which the request values of the RPC should be passed.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.STREAM_UNARY, style.Service.EVENT, None, None,
+      None, None, None, None, behavior, None)
+
+
+def stream_stream_event(behavior):
+  """Creates an interfaces.MethodImplementation for the given behavior.
+
+  Args:
+    behavior: The implementation of a stream-stream RPC method as a callable
+      value that takes a stream.Consumer to which to pass the response values
+      of the RPC and a face_interfaces.RpcContext and returns a stream.Consumer
+      to which the request values of the RPC should be passed.
+
+  Returns:
+    An interfaces.MethodImplementation derived from the given behavior.
+  """
+  return _MethodImplementation(
+      cardinality.Cardinality.STREAM_STREAM, style.Service.EVENT, None, None,
+      None, None, None, None, None, behavior)
diff --git a/src/python/src/grpc/framework/common/style.py b/src/python/src/grpc/framework/common/style.py
new file mode 100644
index 0000000000..6ae694bdcb
--- /dev/null
+++ b/src/python/src/grpc/framework/common/style.py
@@ -0,0 +1,40 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Defines an enum for classifying RPC methods by control flow semantics."""
+
+import enum
+
+
+@enum.unique
+class Service(enum.Enum):
+  """Describes the control flow style of RPC method implementation."""
+
+  INLINE = 'inline'
+  EVENT = 'event'
diff --git a/src/python/src/grpc/framework/face/utilities.py b/src/python/src/grpc/framework/face/utilities.py
new file mode 100644
index 0000000000..5e34be37da
--- /dev/null
+++ b/src/python/src/grpc/framework/face/utilities.py
@@ -0,0 +1,221 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Utilities for the face layer of RPC Framework."""
+
+# stream is referenced from specification in this module.
+from grpc.framework.face import interfaces
+from grpc.framework.foundation import stream  # pylint: disable=unused-import
+
+
+class _InlineUnaryUnaryMethod(interfaces.InlineValueInValueOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, request, context):
+    return self._behavior(request, context)
+
+
+class _InlineUnaryStreamMethod(interfaces.InlineValueInStreamOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, request, context):
+    return self._behavior(request, context)
+
+
+class _InlineStreamUnaryMethod(interfaces.InlineStreamInValueOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, request_iterator, context):
+    return self._behavior(request_iterator, context)
+
+
+class _InlineStreamStreamMethod(interfaces.InlineStreamInStreamOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, request_iterator, context):
+    return self._behavior(request_iterator, context)
+
+
+class _EventUnaryUnaryMethod(interfaces.EventValueInValueOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, request, response_callback, context):
+    return self._behavior(request, response_callback, context)
+
+
+class _EventUnaryStreamMethod(interfaces.EventValueInStreamOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, request, response_consumer, context):
+    return self._behavior(request, response_consumer, context)
+
+
+class _EventStreamUnaryMethod(interfaces.EventStreamInValueOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, response_callback, context):
+    return self._behavior(response_callback, context)
+
+
+class _EventStreamStreamMethod(interfaces.EventStreamInStreamOutMethod):
+
+  def __init__(self, behavior):
+    self._behavior = behavior
+
+  def service(self, response_consumer, context):
+    return self._behavior(response_consumer, context)
+
+
+def inline_unary_unary_method(behavior):
+  """Creates an interfaces.InlineValueInValueOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a unary-unary RPC method as a callable
+      value that takes a request value and an interfaces.RpcContext object and
+      returns a response value.
+
+  Returns:
+    An interfaces.InlineValueInValueOutMethod derived from the given behavior.
+  """
+  return _InlineUnaryUnaryMethod(behavior)
+
+
+def inline_unary_stream_method(behavior):
+  """Creates an interfaces.InlineValueInStreamOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a unary-stream RPC method as a callable
+      value that takes a request value and an interfaces.RpcContext object and
+      returns an iterator of response values.
+
+  Returns:
+    An interfaces.InlineValueInStreamOutMethod derived from the given behavior.
+  """
+  return _InlineUnaryStreamMethod(behavior)
+
+
+def inline_stream_unary_method(behavior):
+  """Creates an interfaces.InlineStreamInValueOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a stream-unary RPC method as a callable
+      value that takes an iterator of request values and an
+      interfaces.RpcContext object and returns a response value.
+
+  Returns:
+    An interfaces.InlineStreamInValueOutMethod derived from the given behavior.
+  """
+  return _InlineStreamUnaryMethod(behavior)
+
+
+def inline_stream_stream_method(behavior):
+  """Creates an interfaces.InlineStreamInStreamOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a stream-stream RPC method as a callable
+      value that takes an iterator of request values and an
+      interfaces.RpcContext object and returns an iterator of response values.
+
+  Returns:
+    An interfaces.InlineStreamInStreamOutMethod derived from the given
+      behavior.
+  """
+  return _InlineStreamStreamMethod(behavior)
+
+
+def event_unary_unary_method(behavior):
+  """Creates an interfaces.EventValueInValueOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a unary-unary RPC method as a callable
+      value that takes a request value, a response callback to which to pass
+      the response value of the RPC, and an interfaces.RpcContext.
+
+  Returns:
+    An interfaces.EventValueInValueOutMethod derived from the given behavior.
+  """
+  return _EventUnaryUnaryMethod(behavior)
+
+
+def event_unary_stream_method(behavior):
+  """Creates an interfaces.EventValueInStreamOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a unary-stream RPC method as a callable
+      value that takes a request value, a stream.Consumer to which to pass the
+      response values of the RPC, and an interfaces.RpcContext.
+
+  Returns:
+    An interfaces.EventValueInStreamOutMethod derived from the given behavior.
+  """
+  return _EventUnaryStreamMethod(behavior)
+
+
+def event_stream_unary_method(behavior):
+  """Creates an interfaces.EventStreamInValueOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a stream-unary RPC method as a callable
+      value that takes a response callback to which to pass the response value
+      of the RPC and an interfaces.RpcContext and returns a stream.Consumer to
+      which the request values of the RPC should be passed.
+
+  Returns:
+    An interfaces.EventStreamInValueOutMethod derived from the given behavior.
+  """
+  return _EventStreamUnaryMethod(behavior)
+
+
+def event_stream_stream_method(behavior):
+  """Creates an interfaces.EventStreamInStreamOutMethod from a behavior.
+
+  Args:
+    behavior: The implementation of a stream-stream RPC method as a callable
+      value that takes a stream.Consumer to which to pass the response values
+      of the RPC and an interfaces.RpcContext and returns a stream.Consumer to
+      which the request values of the RPC should be passed.
+
+  Returns:
+    An interfaces.EventStreamInStreamOutMethod derived from the given behavior.
+  """
+  return _EventStreamStreamMethod(behavior)
diff --git a/src/python/src/grpc/framework/foundation/activated.py b/src/python/src/grpc/framework/foundation/activated.py
new file mode 100644
index 0000000000..426a71c705
--- /dev/null
+++ b/src/python/src/grpc/framework/foundation/activated.py
@@ -0,0 +1,65 @@
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Interfaces related to streams of values or objects."""
+
+import abc
+
+
+class Activated(object):
+  """Interface for objects that may be started and stopped.
+
+  Values implementing this type must also implement the context manager
+  protocol.
+  """
+  __metaclass__ = abc.ABCMeta
+
+  @abc.abstractmethod
+  def __enter__(self):
+    """See the context manager protocol for specification."""
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    """See the context manager protocol for specification."""
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def start(self):
+    """Activates this object.
+
+    Returns:
+      A value equal to the value returned by this object's __enter__ method.
+    """
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def stop(self):
+    """Deactivates this object."""
+    raise NotImplementedError()
diff --git a/src/python/src/setup.py b/src/python/src/setup.py
index 8e33ebb31c..e3f13fa5c8 100644
--- a/src/python/src/setup.py
+++ b/src/python/src/setup.py
@@ -56,12 +56,13 @@ _EXTENSION_MODULE = _core.Extension(
     libraries=_EXTENSION_LIBRARIES,
     )
 
-_PACKAGES=(
+_PACKAGES = (
     'grpc',
     'grpc._adapter',
     'grpc._junkdrawer',
     'grpc.early_adopter',
     'grpc.framework',
+    'grpc.framework.assembly',
     'grpc.framework.base',
     'grpc.framework.base.packets',
     'grpc.framework.common',