add solution-wide code analysis config

Disabled for now, since it'll be a bit of a refactor to enable them

Dalamud/Utility/TaskExtensions.cs

@@ -0,0 +1,75 @@
+// Copyright (c) 2024 ppy Pty Ltd <contact@ppy.sh>.
+// Copyright (c) 2024 XIVLauncher & Dalamud contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Dalamud.Utility;
+
+/// <summary>
+/// Extension methods to make working with <see cref="Task"/> easier.
+/// </summary>
+public static class TaskExtensions
+{
+    /// <summary>
+    /// Safe alternative to Task.Wait which ensures the calling thread is not a thread pool thread.
+    /// </summary>
+    /// <param name="task">The task to be awaited.</param>
+    public static void WaitSafely(this Task task)
+    {
+        if (!IsWaitingValid(task))
+            throw new InvalidOperationException($"Can't use {nameof(WaitSafely)} from inside an async operation.");
+
+#pragma warning disable RS0030
+        task.Wait();
+#pragma warning restore RS0030
+    }
+
+    /// <summary>
+    /// Safe alternative to Task.Result which ensures the calling thread is not a thread pool thread.
+    /// </summary>
+    /// <param name="task">The target task.</param>
+    /// <typeparam name="T">The type of the result.</typeparam>
+    /// <returns>The result.</returns>
+    public static T GetResultSafely<T>(this Task<T> task)
+    {
+        // We commonly access `.Result` from within `ContinueWith`, which is a safe usage (the task is guaranteed to be completed).
+        // Unfortunately, the only way to allow these usages is to check whether the task is completed or not here.
+        // This does mean that there could be edge cases where this safety is skipped (ie. if the majority of executions complete
+        // immediately).
+        if (!task.IsCompleted && !IsWaitingValid(task))
+            throw new InvalidOperationException($"Can't use {nameof(GetResultSafely)} from inside an async operation.");
+
+#pragma warning disable RS0030
+        return task.Result;
+#pragma warning restore RS0030
+    }
+
+    private static bool IsWaitingValid(Task task)
+    {
+        // In the case the task has been started with the LongRunning flag, it will not be in the TPL thread pool and we can allow waiting regardless.
+        if (task.CreationOptions.HasFlag(TaskCreationOptions.LongRunning))
+            return true;
+
+        // Otherwise only allow waiting from a non-TPL thread pool thread.
+        return !Thread.CurrentThread.IsThreadPoolThread;
+    }
+}