Back-up commit.

Author: Marwan Mattar

com.unity.ml-agents/Runtime/SideChannels/EnvironmentParametersChannel.cs

@@ -3,6 +3,14 @@
 
 namespace MLAgents.SideChannels
 {
+    /// <summary>
+    /// Lists the different data types supported.
+    /// </summary>
+    internal enum EnvironmentDataTypes
+    {
+        Float = 0
+    }
+
     /// <summary>
     /// A side channel that manages the environment parameter values from Python. Currently
     /// limited to parameters of type float.
@@ -28,13 +36,21 @@ internal EnvironmentParametersChannel()
         public override void OnMessageReceived(IncomingMessage msg)
         {
             var key = msg.ReadString();
-            var value = msg.ReadFloat32();
+            var type = msg.ReadInt32();
+            if ((int)EnvironmentDataTypes.Float == type)
+            {
+                var value = msg.ReadFloat32();
 
-            m_Parameters[key] = value;
+                m_Parameters[key] = value;
 
-            Action<float> action;
-            m_RegisteredActions.TryGetValue(key, out action);
-            action?.Invoke(value);
+                Action<float> action;
+                m_RegisteredActions.TryGetValue(key, out action);
+                action?.Invoke(value);
+            }
+            else
+            {
+                throw new UnityAgentsException("EnvironmentParametersChannel only supports floats.");
+            }
         }
 
         /// <summary>

ml-agents-envs/mlagents_envs/side_channel/environment_parameters_channel.py

@@ -0,0 +1,65 @@
+from mlagents_envs.side_channel import SideChannel, IncomingMessage, OutgoingMessage
+import uuid
+from typing import Dict, Optional, List
+
+
+class EnvironmentParametersChannel(SideChannel):
+    """
+    This is the SideChannel for float properties shared with Unity.
+    You can modify the float properties of an environment with the commands
+    set_property, get_property and list_properties.
+    """
+
+    def __init__(self, channel_id: uuid.UUID = None) -> None:
+        self._float_properties: Dict[str, float] = {}
+        if channel_id is None:
+            channel_id = uuid.UUID(("534c891e-810f-11ea-a9d0-822485860400"))
+        super().__init__(channel_id)
+
+    def on_message_received(self, msg: IncomingMessage) -> None:
+        """
+        Is called by the environment to the side channel. Can be called
+        multiple times per step if multiple messages are meant for that
+        SideChannel.
+        Note that Python should never receive an environment parameters from
+        Unity
+        """
+        raise UnityCommunicationException(
+            "The EnvironmentParametersChannel received a message from Unity, "
+            + "this should not have happend."
+        )
+
+    def set_float_property(self, key: str, value: float) -> None:
+        """
+        Sets a property in the Unity Environment.
+        :param key: The string identifier of the property.
+        :param value: The float value of the property.
+        """
+        self._float_properties[key] = value
+        msg = OutgoingMessage()
+        msg.write_string(key)
+        msg.write_float32(value)
+        super().queue_message_to_send(msg)
+
+    def get_float_property(self, key: str) -> Optional[float]:
+        """
+        Gets a property in the Unity Environment. If the property was not
+        found, will return None.
+        :param key: The string identifier of the property.
+        :return: The float value of the property or None.
+        """
+        return self._float_properties.get(key)
+
+    def list_properties(self) -> List[str]:
+        """
+        Returns a list of all the string identifiers of the properties
+        currently present in the Unity Environment.
+        """
+        return list(self._float_properties.keys())
+
+    def get_property_dict_copy(self) -> Dict[str, float]:
+        """
+        Returns a copy of the float properties.
+        :return:
+        """
+        return dict(self._float_properties)

ml-agents/mlagents/trainers/simple_env_manager.py

@@ -5,7 +5,7 @@
 from mlagents_envs.timers import timed
 from mlagents.trainers.action_info import ActionInfo
 from mlagents.trainers.brain import BrainParameters
-from mlagents_envs.side_channel.float_properties_channel import FloatPropertiesChannel
+from mlagents_envs.side_channel.environment_parameters_channel import EnvironmentParameters
 from mlagents.trainers.brain_conversion_utils import behavior_spec_to_brain_parameters
 
 
@@ -15,9 +15,9 @@ class SimpleEnvManager(EnvManager):
     This is generally only useful for testing; see SubprocessEnvManager for a production-quality implementation.
     """
 
-    def __init__(self, env: BaseEnv, float_prop_channel: FloatPropertiesChannel):
+    def __init__(self, env: BaseEnv, environment_parameters_channel: EnvironmentParameters):
         super().__init__()
-        self.shared_float_properties = float_prop_channel
+        self.environment_parameters_channel = environment_parameters_channel
         self.env = env
         self.previous_step: EnvironmentStep = EnvironmentStep.empty(0)
         self.previous_all_action_info: Dict[str, ActionInfo] = {}

ml-agents/mlagents/trainers/subprocess_env_manager.py

@@ -113,7 +113,7 @@ def worker(
     env_factory: Callable[
         [int, List[SideChannel]], UnityEnvironment
     ] = cloudpickle.loads(pickled_env_factory)
-    shared_float_properties = FloatPropertiesChannel()
+    environment_parameters_channel = EnvironmentParametersChannel()
     engine_configuration_channel = EngineConfigurationChannel()
     engine_configuration_channel.set_configuration(engine_configuration)
     stats_channel = StatsSideChannel()
@@ -139,7 +139,7 @@ def external_brains():
     try:
         env = env_factory(
             worker_id,
-            [shared_float_properties, engine_configuration_channel, stats_channel],
+            [environment_parameters_channel, engine_configuration_channel, stats_channel],
         )
         while True:
             req: EnvironmentRequest = parent_conn.recv()
@@ -168,11 +168,9 @@ def external_brains():
             elif req.cmd == EnvironmentCommand.EXTERNAL_BRAINS:
                 _send_response(EnvironmentCommand.EXTERNAL_BRAINS, external_brains())
             elif req.cmd == EnvironmentCommand.GET_PROPERTIES:
-                reset_params = shared_float_properties.get_property_dict_copy()
+                reset_params = environment_parameters_channel.get_property_dict_copy()
                 _send_response(EnvironmentCommand.GET_PROPERTIES, reset_params)
             elif req.cmd == EnvironmentCommand.RESET:
-                for k, v in req.payload.items():
-                    shared_float_properties.set_property(k, v)
                 env.reset()
                 all_step_result = _generate_all_results()
                 _send_response(EnvironmentCommand.RESET, all_step_result)