MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4namespace System.Management.Automation5{6    using System;7    using System.Diagnostics.Eventing;8    using System.Management.Automation.Tracing;9    using System.Threading;10 11    /// <summary>12    ///     An object that can be used to execute a method on a threadpool thread while correctly13    ///     managing system state, such as flowing ETW activities from the current thread to the14    ///     threadpool thread.15    /// </summary>16    public interface IBackgroundDispatcher17    {18        /// <summary>19        ///     Works the same as <see cref="ThreadPool.QueueUserWorkItem(WaitCallback)" />, except that it20        ///     also manages system state correctly.21        /// </summary>22        bool QueueUserWorkItem(WaitCallback callback);23 24        /// <summary>25        ///     Works the same as <see cref="ThreadPool.QueueUserWorkItem(WaitCallback, object)" />, except that it26        ///     also manages system state correctly.27        /// </summary>28        bool QueueUserWorkItem(WaitCallback callback, object state);29 30        /// <summary>31        ///     Works the same as BeginInvoke would for any other delegate, except that it also manages system state correctly.32        /// </summary>33        IAsyncResult BeginInvoke(WaitCallback callback, object state, AsyncCallback completionCallback, object asyncState);34 35        /// <summary>36        ///     Works the same as EndInvoke would for any other delegate, except that it also manages system state correctly.37        /// </summary>38        void EndInvoke(IAsyncResult asyncResult);39    }40 41    /// <summary>42    ///     A simple implementation of <see cref="IBackgroundDispatcher" />.43    /// </summary>44    public class BackgroundDispatcher :45        IBackgroundDispatcher46    {47        #region Instance Data48 49        private readonly IMethodInvoker _etwActivityMethodInvoker;50        private readonly WaitCallback _invokerWaitCallback;51 52        #endregion53 54        #region Creation/Cleanup55 56        /// <summary>57        ///     Creates a <see cref="BackgroundDispatcher" /> that uses an <see cref="EtwEventCorrelator" />58        ///     for activity creation and correlation.59        /// </summary>60        /// <param name="transferProvider">The <see cref="EventProvider" /> to use when logging transfer events61        ///     during activity correlation.</param>62        /// <param name="transferEvent">The <see cref="EventDescriptor" /> to use when logging transfer events63        ///     during activity correlation.</param>64        public BackgroundDispatcher(EventProvider transferProvider, EventDescriptor transferEvent)65            : this(new EtwActivityReverterMethodInvoker(new EtwEventCorrelator(transferProvider, transferEvent)))66        {67            // nothing68        }69 70        // internal for unit testing only.  Otherwise, would be private.71        internal BackgroundDispatcher(IMethodInvoker etwActivityMethodInvoker)72        {73            ArgumentNullException.ThrowIfNull(etwActivityMethodInvoker);74            _etwActivityMethodInvoker = etwActivityMethodInvoker;75            _invokerWaitCallback = DoInvoker;76        }77 78        #endregion79 80        #region Instance Utilities81 82        private void DoInvoker(object invokerArgs)83        {84            var invokerArgsArray = (object[])invokerArgs;85 86            _etwActivityMethodInvoker.Invoker.DynamicInvoke(invokerArgsArray);87        }88 89        #endregion90 91        #region Instance Access92 93        /// <summary>94        ///     Implements <see cref="IBackgroundDispatcher.QueueUserWorkItem(WaitCallback)" />.95        /// </summary>96        public bool QueueUserWorkItem(WaitCallback callback)97        {98            return QueueUserWorkItem(callback, null);99        }100 101        /// <summary>102        ///     Implements <see cref="IBackgroundDispatcher.QueueUserWorkItem(WaitCallback, object)" />.103        /// </summary>104        public bool QueueUserWorkItem(WaitCallback callback, object state)105        {106            var invokerArgs = _etwActivityMethodInvoker.CreateInvokerArgs(callback, new object[] { state });107 108            var result = ThreadPool.QueueUserWorkItem(_invokerWaitCallback, invokerArgs);109            return result;110        }111 112        /// <summary>113        ///     Implements <see cref="IBackgroundDispatcher.BeginInvoke(WaitCallback, object, AsyncCallback, object)" />.114        /// </summary>115        public IAsyncResult BeginInvoke(WaitCallback callback, object state, AsyncCallback completionCallback, object asyncState)116        {117            var invokerArgs = _etwActivityMethodInvoker.CreateInvokerArgs(callback, new object[] { state });118 119            var result = _invokerWaitCallback.BeginInvoke(invokerArgs, completionCallback, asyncState);120            return result;121        }122 123        /// <summary>124        ///     Implements <see cref="IBackgroundDispatcher.EndInvoke(IAsyncResult)" />.125        /// </summary>126        public void EndInvoke(IAsyncResult asyncResult)127        {128            _invokerWaitCallback.EndInvoke(asyncResult);129        }130 131        #endregion132    }133}134