Merge remote-tracking branch 'origin/master' into net8-rollup

Dalamud/Utility/Api10ToDoAttribute.cs

@@ -0,0 +1,19 @@
+namespace Dalamud.Utility;
+
+/// <summary>
+/// Utility class for marking something to be changed for API 10, for ease of lookup.
+/// </summary>
+[AttributeUsage(AttributeTargets.All, Inherited = false)]
+internal sealed class Api10ToDoAttribute : Attribute
+{
+    /// <summary>
+    /// Marks that this exists purely for making API 9 plugins work.
+    /// </summary>
+    public const string DeleteCompatBehavior = "Delete. This is for making API 9 plugins work.";
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Api10ToDoAttribute"/> class.
+    /// </summary>
+    /// <param name="what">The explanation.</param>
+    public Api10ToDoAttribute(string what) => _ = what;
+}

Dalamud/Utility/IRefCountable.cs

@@ -0,0 +1,77 @@
+using System.Diagnostics;
+using System.Threading;
+
+namespace Dalamud.Utility;
+
+/// <summary>
+/// Interface for reference counting.
+/// </summary>
+internal interface IRefCountable : IDisposable
+{
+    /// <summary>
+    /// Result for <see cref="IRefCountable.AlterRefCount"/>.
+    /// </summary>
+    public enum RefCountResult
+    {
+        /// <summary>
+        /// The object still has remaining references. No futher action should be done.
+        /// </summary>
+        StillAlive = 1,
+
+        /// <summary>
+        /// The last reference to the object has been released. The object should be fully released.
+        /// </summary>
+        FinalRelease = 2,
+
+        /// <summary>
+        /// The object already has been disposed. <see cref="ObjectDisposedException"/> may be thrown.
+        /// </summary>
+        AlreadyDisposed = 3,
+    }
+
+    /// <summary>
+    /// Adds a reference to this reference counted object.
+    /// </summary>
+    /// <returns>The new number of references.</returns>
+    int AddRef();
+
+    /// <summary>
+    /// Releases a reference from this reference counted object.<br />
+    /// When all references are released, the object will be fully disposed.
+    /// </summary>
+    /// <returns>The new number of references.</returns>
+    int Release();
+
+    /// <summary>
+    /// Alias for <see cref="Release()"/>.
+    /// </summary>
+    void IDisposable.Dispose() => this.Release();
+
+    /// <summary>
+    /// Alters <paramref name="refCount"/> by <paramref name="delta"/>.
+    /// </summary>
+    /// <param name="delta">The delta to the reference count.</param>
+    /// <param name="refCount">The reference to the reference count.</param>
+    /// <param name="newRefCount">The new reference count.</param>
+    /// <returns>The followup action that should be done.</returns>
+    public static RefCountResult AlterRefCount(int delta, ref int refCount, out int newRefCount)
+    {
+        Debug.Assert(delta is 1 or -1, "delta must be 1 or -1");
+
+        while (true)
+        {
+            var refCountCopy = refCount;
+            if (refCountCopy <= 0)
+            {
+                newRefCount = refCountCopy;
+                return RefCountResult.AlreadyDisposed;
+            }
+
+            newRefCount = refCountCopy + delta;
+            if (refCountCopy != Interlocked.CompareExchange(ref refCount, newRefCount, refCountCopy))
+                continue;
+
+            return newRefCount == 0 ? RefCountResult.FinalRelease : RefCountResult.StillAlive;
+        }
+    }
+}