UNI-62864: shutdown on domain reload.

Shut down python when the domain that loaded python reloads.
pythonnet · benoithudson · Sep 14, 2018 · Sep 14, 2018 · Sep 26, 2018 · Sep 26, 2018
commit c07fff02f4fe30a725e8df1b3aaab3aa2a87ff97
diff --git a/src/embed_tests/TestDomainReload.cs b/src/embed_tests/TestDomainReload.cs
@@ -2,6 +2,7 @@
 using System.CodeDom.Compiler;
 using System.Reflection;
 using NUnit.Framework;
+using Python.Runtime;
 
 namespace Python.EmbeddingTest
 {
@@ -48,6 +49,9 @@ public static void DomainReloadAndGC()
             Assembly pythonRunner1 = BuildAssembly("test1");
             RunAssemblyAndUnload(pythonRunner1, "test1");
 
+            // Verify that python is not initialized even though we ran it.
+            Assert.That(Runtime.Runtime.Py_IsInitialized(), Is.Zero);
+
             // This caused a crash because objects allocated in pythonRunner1
             // still existed in memory, but the code to do python GC on those
             // objects is gone.

diff --git a/src/runtime/pythonengine.cs b/src/runtime/pythonengine.cs
@@ -220,9 +220,17 @@ public static void Initialize(IEnumerable<string> args, bool setSysArgv = true)
                 {
                     locals.Dispose();
                 }
+
+                // Make sure we clean up properly on app domain unload.
+                AppDomain.CurrentDomain.DomainUnload += OnDomainUnload;
             }
         }
 
+        static void OnDomainUnload(object _, EventArgs __)
+        {
+            Shutdown();
+        }
+
         /// <summary>
         /// A helper to perform initialization from the context of an active
         /// CPython interpreter process - this bootstraps the managed runtime
@@ -303,6 +311,8 @@ public static void Shutdown()
                 _pythonPath = IntPtr.Zero;
 
                 Runtime.Shutdown();
+
+                AppDomain.CurrentDomain.DomainUnload -= OnDomainUnload;
                 initialized = false;
             }
         }