pythonnet · lostmsu · Mar 10, 2021 · Feb 24, 2021
diff --git a/src/runtime/pythonengine.cs b/src/runtime/pythonengine.cs
@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Threading;

 namespace Python.Runtime
 {
@@ -51,6 +52,9 @@ public static bool IsInitialized
            get { return initialized; }
        }

+        /// <summary>Set to <c>true</c> to enable GIL debugging assistance.</summary>
+        public static bool DebugGIL { get; set; } = false;
+
        internal static DelegateManager DelegateManager
        {
            get
@@ -668,7 +672,7 @@ public static GILState GIL()
                PythonEngine.Initialize();
            }

-            return new GILState();
+            return PythonEngine.DebugGIL ? new DebugGILState() : new GILState();
        }

        public static PyScope CreateScope()
@@ -693,7 +697,7 @@ internal GILState()
                state = PythonEngine.AcquireLock();
            }

-            public void Dispose()
+            public virtual void Dispose()
            {
                if (this.isDisposed) return;

@@ -704,7 +708,23 @@ public void Dispose()

            ~GILState()
            {
-                Dispose();
+                throw new InvalidOperationException("GIL must always be released, and it must be released from the same thread that acquired it.");
+            }
+        }
+
+        public class DebugGILState : GILState
+        {
+            readonly Thread owner;
+            internal DebugGILState() : base()
+            {
+                this.owner = Thread.CurrentThread;
+            }
+            public override void Dispose()
+            {
+                if (this.owner != Thread.CurrentThread)
+                    throw new InvalidOperationException("GIL must always be released from the same thread, that acquired it");
+
+                base.Dispose();
            }
        }