From 0534d7f3c9864336e018ae366c6f3295c8402e9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix=20Bourbonnais?=
 <felix.bourbonnais@imaginary-spaces.com>
Date: Thu, 23 Jun 2022 15:33:29 -0400
Subject: [PATCH] Grab the GIL on shutdown when checking for exceptions

The GIL isn't taken when being called from the DomainUnload handler.
---
 src/runtime/PythonEngine.cs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/runtime/PythonEngine.cs b/src/runtime/PythonEngine.cs
index f184ebe88..5d1069db0 100644
--- a/src/runtime/PythonEngine.cs
+++ b/src/runtime/PythonEngine.cs
@@ -355,12 +355,26 @@ public static void Shutdown()
             {
                 return;
             }
+
+            // If we're embedded, we need to take the GIL, if it wasn't already 
+            // taken, as we may get called from the DomainUnload handler.
+            var pyGILState = PyGILState.PyGILState_UNLOCKED;
+            if (!Runtime.HostedInPython)
+            {
+                pyGILState = Runtime.PyGILState_Ensure();
+            }
+
             if (Exceptions.ErrorOccurred())
             {
                 throw new InvalidOperationException(
                     "Python error indicator is set",
                     innerException: PythonException.PeekCurrentOrNull(out _));
             }
+
+            if (!Runtime.HostedInPython)
+            {
+                Runtime.PyGILState_Release(pyGILState);
+            }
             // If the shutdown handlers trigger a domain unload,
             // don't call shutdown again.
             AppDomain.CurrentDomain.DomainUnload -= OnDomainUnload;