refactor: Unify ExecutorIsh and ExecutorRegistration

* Switch to more modern Record type-tree for Sum Types
* Unify APIs for getting ExecutorRegistration
* Fix an issue where workflows consisting entirely of cross-run shareable executors which are not instance-resettable do not properly clear state when running non-concurrently.

Author: lokitoth

dotnet/samples/GettingStarted/Workflows/_Foundational/06_SubWorkflows/Program.cs

@@ -40,7 +40,7 @@ private static async Task Main()
             .Build();
 
         // Step 2: Configure the sub-workflow as an executor for use in the parent workflow
-        ExecutorIsh subWorkflowExecutor = subWorkflow.ConfigureSubWorkflow("TextProcessingSubWorkflow");
+        ExecutorRegistration subWorkflowExecutor = subWorkflow.AsExecutor("TextProcessingSubWorkflow");
 
         // Step 3: Build a main workflow that uses the sub-workflow as an executor
         Console.WriteLine("Building main workflow that uses the sub-workflow as an executor...\n");

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Interpreter/WorkflowModelBuilder.cs

@@ -24,7 +24,7 @@ public void Connect(IModeledAction source, IModeledAction target, Func<object?,
             condition);
     }
 
-    private static ExecutorIsh GetExecutorIsh(IModeledAction action) =>
+    private static ExecutorRegistration GetExecutorIsh(IModeledAction action) =>
         action switch
         {
             RequestPortAction port => port.RequestPort,

dotnet/src/Microsoft.Agents.AI.Workflows/AIAgentRegistration.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.Workflows.Specialized;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Agents.AI.Workflows;
+
+/// <summary>
+/// Represents the registration details for an AI agent, including configuration options for event emission.
+/// </summary>
+/// <param name="Agent">The AI agent.</param>
+/// <param name="EmitEvents">Specifies whether the agent should emit events. If null, the default behavior is applied.</param>
+public record AIAgentRegistration(AIAgent Agent, bool EmitEvents = false)
+    : ExecutorRegistration(Throw.IfNull(Agent).Name ?? Throw.IfNull(Agent.Id),
+                           (_) => new(new AIAgentHostExecutor(Agent, EmitEvents)),
+                           typeof(AIAgentHostExecutor),
+                           Agent)
+{
+    /// <inheritdoc/>
+    public override bool SupportsConcurrentSharedExecution => true;
+
+    /// <inheritdoc/>
+    public override bool SupportsResetting => false;
+}

dotnet/src/Microsoft.Agents.AI.Workflows/AgentWorkflowBuilder.cs

@@ -39,7 +39,7 @@ private static Workflow BuildSequentialCore(string? workflowName, params IEnumer
         // Create a builder that chains the agents together in sequence. The workflow simply begins
         // with the first agent in the sequence.
         WorkflowBuilder? builder = null;
-        ExecutorIsh? previous = null;
+        ExecutorRegistration? previous = null;
         foreach (var agent in agents)
         {
             AgentRunStreamingExecutor agentExecutor = new(agent, includeInputInOutput: true);
@@ -124,8 +124,8 @@ private static Workflow BuildConcurrentCore(
         // so that the final accumulator receives a single list of messages from each agent. Otherwise, the
         // accumulator would not be able to determine what came from what agent, as there's currently no
         // provenance tracking exposed in the workflow context passed to a handler.
-        ExecutorIsh[] agentExecutors = (from agent in agents select (ExecutorIsh)new AgentRunStreamingExecutor(agent, includeInputInOutput: false)).ToArray();
-        ExecutorIsh[] accumulators = [.. from agent in agentExecutors select (ExecutorIsh)new CollectChatMessagesExecutor($"Batcher/{agent.Id}")];
+        ExecutorRegistration[] agentExecutors = (from agent in agents select (ExecutorRegistration)new AgentRunStreamingExecutor(agent, includeInputInOutput: false)).ToArray();
+        ExecutorRegistration[] accumulators = [.. from agent in agentExecutors select (ExecutorRegistration)new CollectChatMessagesExecutor($"Batcher/{agent.Id}")];
         builder.AddFanOutEdge(start, targets: agentExecutors);
         for (int i = 0; i < agentExecutors.Length; i++)
         {

dotnet/src/Microsoft.Agents.AI.Workflows/ConfiguredExecutorRegistration.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Agents.AI.Workflows;
+
+// TODO: Unwrap the Configured object, just like for WorkflowRegistration
+internal record ConfiguredExecutorRegistration(Configured<Executor> ConfiguredExecutor, Type ExecutorType)
+    : ExecutorRegistration(Throw.IfNull(ConfiguredExecutor).Id,
+                           ConfiguredExecutor.BoundFactoryAsync,
+                           ExecutorType,
+                           ConfiguredExecutor.Raw)
+{
+    /// <inheritdoc/>
+    public override bool SupportsConcurrentSharedExecution => true;
+
+    /// <inheritdoc/>
+    public override bool SupportsResetting => false;
+}

dotnet/src/Microsoft.Agents.AI.Workflows/ExecutorInstanceRegistration.cs

@@ -0,0 +1,35 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Threading.Tasks;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Agents.AI.Workflows;
+
+/// <summary>
+/// Initializes a new instance of the ExecutorRegistrationEx class using the specified executor.
+/// </summary>
+/// <param name="ExecutorInstance">The executor instance to register. Cannot be null.</param>
+public record ExecutorInstanceRegistration(Executor ExecutorInstance)
+    : ExecutorRegistration(Throw.IfNull(ExecutorInstance).Id,
+                           (_) => new(ExecutorInstance),
+                           ExecutorInstance.GetType(),
+                           ExecutorInstance)
+{
+    /// <inheritdoc/>
+    public override bool SupportsConcurrentSharedExecution => this.ExecutorInstance.IsCrossRunShareable;
+
+    /// <inheritdoc/>
+    public override bool SupportsResetting => this.ExecutorInstance is IResettableExecutor;
+
+    /// <inheritdoc/>
+    protected override async ValueTask<bool> ResetCoreAsync()
+    {
+        if (this.ExecutorInstance is IResettableExecutor resettable)
+        {
+            await resettable.ResetAsync().ConfigureAwait(false);
+            return true;
+        }
+
+        return false;
+    }
+}