moving core items to abstractions

moving core items to abstractions

src/Umbraco.Abstractions/IMainDom.cs

@@ -0,0 +1,38 @@
+using System;
+
+namespace Umbraco.Core
+{
+    /// <summary>
+    /// Represents the main AppDomain running for a given application.
+    /// </summary>
+    /// <remarks>
+    /// <para>There can be only one "main" AppDomain running for a given application at a time.</para>
+    /// <para>It is possible to register against the MainDom and be notified when it is released.</para>
+    /// </remarks>
+    public interface IMainDom
+    {
+        /// <summary>
+        /// Gets a value indicating whether the current domain is the main domain.
+        /// </summary>
+        bool IsMainDom { get; }
+
+        /// <summary>
+        /// Registers a resource that requires the current AppDomain to be the main domain to function.
+        /// </summary>
+        /// <param name="release">An action to execute before the AppDomain releases the main domain status.</param>
+        /// <param name="weight">An optional weight (lower goes first).</param>
+        /// <returns>A value indicating whether it was possible to register.</returns>
+        bool Register(Action release, int weight = 100);
+
+        /// <summary>
+        /// Registers a resource that requires the current AppDomain to be the main domain to function.
+        /// </summary>
+        /// <param name="install">An action to execute when registering.</param>
+        /// <param name="release">An action to execute before the AppDomain releases the main domain status.</param>
+        /// <param name="weight">An optional weight (lower goes first).</param>
+        /// <returns>A value indicating whether it was possible to register.</returns>
+        /// <remarks>If registering is successful, then the <paramref name="install"/> action
+        /// is guaranteed to execute before the AppDomain releases the main domain status.</remarks>
+        bool Register(Action install, Action release, int weight = 100);
+    }
+}

src/Umbraco.Abstractions/SimpleMainDom.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Umbraco.Core
+{
+    /// <summary>
+    /// Provides a simple implementation of <see cref="IMainDom"/>.
+    /// </summary>
+    public class SimpleMainDom : IMainDom
+    {
+        private readonly object _locko = new object();
+        private readonly List<KeyValuePair<int, Action>> _callbacks = new List<KeyValuePair<int, Action>>();
+        private bool _isStopping;
+
+        /// <inheritdoc />
+        public bool IsMainDom { get; private set; } = true;
+
+        /// <inheritdoc />
+        public bool Register(Action release, int weight = 100)
+            => Register(null, release, weight);
+
+        /// <inheritdoc />
+        public bool Register(Action install, Action release, int weight = 100)
+        {
+            lock (_locko)
+            {
+                if (_isStopping) return false;
+                install?.Invoke();
+                if (release != null)
+                    _callbacks.Add(new KeyValuePair<int, Action>(weight, release));
+                return true;
+            }
+        }
+
+        public void Stop()
+        {
+            lock (_locko)
+            {
+                if (_isStopping) return;
+                if (IsMainDom == false) return; // probably not needed
+                _isStopping = true;
+            }
+
+            try
+            {
+                foreach (var callback in _callbacks.OrderBy(x => x.Key).Select(x => x.Value))
+                {
+                    callback(); // no timeout on callbacks
+                }
+            }
+            finally
+            {
+                // in any case...
+                IsMainDom = false;
+            }
+        }
+    }
+}