Initial commit of SqlTools Service API

ServiceHost/Utility/AsyncContextThread.cs

@@ -0,0 +1,85 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.PowerShell.EditorServices.Utility
+{
+    /// <summary>
+    /// Provides a simplified interface for creating a new thread
+    /// and establishing an AsyncContext in it.
+    /// </summary>
+    public class AsyncContextThread
+    {
+        #region Private Fields
+
+        private Task threadTask;
+        private string threadName;
+        private CancellationTokenSource threadCancellationToken =
+            new CancellationTokenSource();
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Initializes a new instance of the AsyncContextThread class.
+        /// </summary>
+        /// <param name="threadName">
+        /// The name of the thread for debugging purposes.
+        /// </param>
+        public AsyncContextThread(string threadName)
+        {
+            this.threadName = threadName;
+        }
+
+        #endregion
+
+        #region Public Methods
+
+        /// <summary>
+        /// Runs a task on the AsyncContextThread.
+        /// </summary>
+        /// <param name="taskReturningFunc">
+        /// A Func which returns the task to be run on the thread.
+        /// </param>
+        /// <returns>
+        /// A Task which can be used to monitor the thread for completion.
+        /// </returns>
+        public Task Run(Func<Task> taskReturningFunc)
+        {
+            // Start up a long-running task with the action as the
+            // main entry point for the thread
+            this.threadTask =
+                Task.Factory.StartNew(
+                    () =>
+                    {
+                        // Set the thread's name to help with debugging
+                        Thread.CurrentThread.Name = "AsyncContextThread: " + this.threadName;
+
+                        // Set up an AsyncContext to run the task
+                        AsyncContext.Start(taskReturningFunc);
+                    },
+                    this.threadCancellationToken.Token,
+                    TaskCreationOptions.LongRunning,
+                    TaskScheduler.Default);
+
+            return this.threadTask;
+        }
+
+        /// <summary>
+        /// Stops the thread task.
+        /// </summary>
+        public void Stop()
+        {
+            this.threadCancellationToken.Cancel();
+        }
+
+        #endregion
+    }
+}
+