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

Dalamud/Utility/ThreadBoundTaskScheduler.cs

@@ -0,0 +1,90 @@
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Dalamud.Utility;
+
+/// <summary>
+/// A task scheduler that runs tasks on a specific thread.
+/// </summary>
+internal class ThreadBoundTaskScheduler : TaskScheduler
+{
+    private const byte Scheduled = 0;
+    private const byte Running = 1;
+
+    private readonly ConcurrentDictionary<Task, byte> scheduledTasks = new();
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ThreadBoundTaskScheduler"/> class.
+    /// </summary>
+    /// <param name="boundThread">The thread to bind this task scheduelr to.</param>
+    public ThreadBoundTaskScheduler(Thread? boundThread = null)
+    {
+        this.BoundThread = boundThread;
+    }
+
+    /// <summary>
+    /// Gets or sets the thread this task scheduler is bound to.
+    /// </summary>
+    public Thread? BoundThread { get; set; }
+
+    /// <summary>
+    /// Gets a value indicating whether we're on the bound thread.
+    /// </summary>
+    public bool IsOnBoundThread => Thread.CurrentThread == this.BoundThread;
+
+    /// <summary>
+    /// Runs queued tasks.
+    /// </summary>
+    public void Run()
+    {
+        foreach (var task in this.scheduledTasks.Keys)
+        {
+            if (!this.scheduledTasks.TryUpdate(task, Running, Scheduled))
+                continue;
+
+            _ = this.TryExecuteTask(task);
+        }
+    }
+
+    /// <inheritdoc/>
+    protected override IEnumerable<Task> GetScheduledTasks()
+    {
+        return this.scheduledTasks.Keys;
+    }
+
+    /// <inheritdoc/>
+    protected override void QueueTask(Task task)
+    {
+        this.scheduledTasks[task] = Scheduled;
+    }
+
+    /// <inheritdoc/>
+    protected override bool TryDequeue(Task task)
+    {
+        if (!this.scheduledTasks.TryRemove(task, out _))
+            return false;
+        return true;
+    }
+
+    /// <inheritdoc/>
+    protected override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued)
+    {
+        if (!this.IsOnBoundThread)
+            return false;
+
+        if (taskWasPreviouslyQueued && !this.scheduledTasks.TryUpdate(task, Running, Scheduled))
+            return false;
+
+        _ = this.TryExecuteTask(task);
+        return true;
+    }
+
+    private new bool TryExecuteTask(Task task)
+    {
+        var r = base.TryExecuteTask(task);
+        this.scheduledTasks.Remove(task, out _);
+        return r;
+    }
+}