pythonnet
diff --git a/‎src/runtime/assemblymanager.cs‎
Lines changed: 4 additions & 1 deletion b/‎src/runtime/assemblymanager.cs‎
Lines changed: 4 additions & 1 deletion
diff --git a/‎src/runtime/importhook.cs‎
Lines changed: 20 additions & 4 deletions b/‎src/runtime/importhook.cs‎
Lines changed: 20 additions & 4 deletions
diff --git a/‎src/runtime/moduleobject.cs‎
Lines changed: 7 additions & 2 deletions b/‎src/runtime/moduleobject.cs‎
Lines changed: 7 additions & 2 deletions
diff --git a/‎src/runtime/native/TypeOffset.cs‎
Lines changed: 2 additions & 1 deletion b/‎src/runtime/native/TypeOffset.cs‎
Lines changed: 2 additions & 1 deletion
@@ -290,7 +290,10 @@ internal static void ScanAssembly(Assembly assembly)
                     for (var n = 0; n < names.Length; n++)
                     {
                         s = n == 0 ? names[0] : s + "." + names[n];
-                        namespaces.TryAdd(s, new ConcurrentDictionary<Assembly, string>());
+                        if (namespaces.TryAdd(s, new ConcurrentDictionary<Assembly, string>()))
+                        {
+                            ImportHook.AddNamespace(s);
+                        }
                     }
                 }
 
 
@@ -1,6 +1,5 @@
 using System;
-using System.Collections.Generic;
-using System.Runtime.InteropServices;
+using System.Collections.Concurrent;
 
 namespace Python.Runtime
 {
@@ -37,6 +36,9 @@ def find_spec(klass, fullname, paths=None, target=None):
         if 'clr' not in sys.modules:
             return None
         clr = sys.modules['clr']
+
+        clr._add_pending_namespaces()
+
         if clr._available_namespaces and fullname in clr._available_namespaces:
             return importlib.machinery.ModuleSpec(fullname, DotNetLoader(), is_package=True)
         return None
@@ -169,12 +171,26 @@ static void TeardownNameSpaceTracking()
             Runtime.PyDict_SetItemString(root.dict, availableNsKey, Runtime.PyNone);
         }
 
-        public static void AddNamespace(string name)
+        static readonly ConcurrentQueue<string> addPending = new();
+        public static void AddNamespace(string name) => addPending.Enqueue(name);
+
+        internal static int AddPendingNamespaces()
+        {
+            int added = 0;
+            while (addPending.TryDequeue(out string ns))
+            {
+                AddNamespaceWithGIL(ns);
+                added++;
+            }
+            return added;
+        }
+
+        internal static void AddNamespaceWithGIL(string name)
         {
             var pyNs = Runtime.PyString_FromString(name);
             try
             {
-                var nsSet = Runtime.PyDict_GetItemString(new BorrowedReference(root.dict), availableNsKey);
+                var nsSet = Runtime.PyDict_GetItemString(root.DictRef, availableNsKey);
                 if (!(nsSet.IsNull  || nsSet.DangerousGetAddress() == Runtime.PyNone))
                 {
                     if (Runtime.PySet_Add(nsSet, new BorrowedReference(pyNs)) != 0)
 
@@ -535,8 +535,9 @@ public static Assembly AddReference(string name)
             // method because it may be called from other threads, leading to deadlocks
             // if it is called while Python code is executing.
             var currNs = AssemblyManager.GetNamespaces().Except(origNs);
-            foreach(var ns in currNs){
-                ImportHook.AddNamespace(ns);
+            foreach(var ns in currNs)
+            {
+                ImportHook.AddNamespaceWithGIL(ns);
             }
             return assembly;
         }
@@ -602,5 +603,9 @@ public static ModuleObject _load_clr_module(PyObject spec)
             mod = ImportHook.Import(modname.ToString());
             return mod;
         }
+
+        [ModuleFunction]
+        [ForbidPythonThreads]
+        public static int _add_pending_namespaces() => ImportHook.AddPendingNamespaces();
     }
 }
@@ -161,7 +161,8 @@ static void ValidateRequiredOffsetsPresent(PropertyInfo[] offsetProperties)
                 "Initialize",
                 "InitializeSlots",
                 "ListAssemblies",
-                "_load_clr_module",
+                nameof(CLRModule._load_clr_module),
+                nameof(CLRModule._add_pending_namespaces),
                 "Release",
                 "Reset",
                 "set_SuppressDocs",
Original file line number	Diff line number	Diff line change
@@ -290,7 +290,10 @@ internal static void ScanAssembly(Assembly assembly)
290	290	for (var n = 0; n < names.Length; n++)
291	291	{
292	292	s = n == 0 ? names[0] : s + "." + names[n];
293		- namespaces.TryAdd(s, new ConcurrentDictionary<Assembly, string>());
	293	+ if (namespaces.TryAdd(s, new ConcurrentDictionary<Assembly, string>()))
	294	+ {
	295	+ ImportHook.AddNamespace(s);
	296	+ }
294	297	}
295	298	}
296	299
Original file line number	Diff line number	Diff line change
@@ -535,8 +535,9 @@ public static Assembly AddReference(string name)
535	535	// method because it may be called from other threads, leading to deadlocks
536	536	// if it is called while Python code is executing.
537	537	var currNs = AssemblyManager.GetNamespaces().Except(origNs);
538		- foreach(var ns in currNs){
539		- ImportHook.AddNamespace(ns);
	538	+ foreach(var ns in currNs)
	539	+ {
	540	+ ImportHook.AddNamespaceWithGIL(ns);
540	541	}
541	542	return assembly;
542	543	}
@@ -602,5 +603,9 @@ public static ModuleObject _load_clr_module(PyObject spec)
602	603	mod = ImportHook.Import(modname.ToString());
603	604	return mod;
604	605	}
	606	+
	607	+ [ModuleFunction]
	608	+ [ForbidPythonThreads]
	609	+ public static int _add_pending_namespaces() => ImportHook.AddPendingNamespaces();
605	610	}
606	611	}