py::mod_gil_not_used() suggestion.

Author: rwgk

include/pybind11/pybind11.h

@@ -1206,7 +1206,15 @@ struct handle_type_name<cpp_function> {
 
 PYBIND11_NAMESPACE_END(detail)
 
-struct gil_not_used {};
+// Use to activate Py_MOD_GIL_NOT_USED.
+class mod_gil_not_used {
+public:
+    mod_gil_not_used(bool flag = true) : flag_(flag) {}
+    bool flag() const { return flag_; }
+
+private:
+    bool flag_;
+};
 
 /// Wrapper for Python extension modules
 class module_ : public object {
@@ -1308,21 +1316,11 @@ class module_ : public object {
 
         ``def`` should point to a statically allocated module_def.
     \endrst */
-    static module_ create_extension_module(const char *name, const char *doc, module_def *def) {
-        return _create_extension_module(name, doc, def, false);
-    }
-
-    static module_
-    create_extension_module(const char *name, const char *doc, module_def *def, gil_not_used) {
-        return _create_extension_module(name, doc, def, true);
-    }
-
-private:
-    static module_ _create_extension_module(const char *name,
-                                            const char *doc,
-                                            module_def *def,
-                                            bool gil_disabled) {
-
+    static module_ create_extension_module(const char *name,
+                                           const char *doc,
+                                           module_def *def,
+                                           mod_gil_not_used gil_not_used
+                                           = mod_gil_not_used(false)) {
         // module_def is PyModuleDef
         // Placement new (not an allocation).
         def = new (def)
@@ -1342,7 +1340,7 @@ class module_ : public object {
             }
             pybind11_fail("Internal error in module_::create_extension_module()");
         }
-        if (gil_disabled) {
+        if (gil_not_used.flag()) {
 #ifdef Py_GIL_DISABLED
             PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
 #endif

tests/eigen_tensor_avoid_stl_array.cpp

@@ -11,6 +11,6 @@
 
 #include "test_eigen_tensor.inl"
 
-PYBIND11_MODULE(eigen_tensor_avoid_stl_array, m, pybind11::gil_not_used()) {
+PYBIND11_MODULE(eigen_tensor_avoid_stl_array, m, pybind11::mod_gil_not_used()) {
     eigen_tensor_test::test_module(m);
 }

tests/pybind11_cross_module_tests.cpp

@@ -16,7 +16,7 @@
 #include <numeric>
 #include <utility>
 
-PYBIND11_MODULE(pybind11_cross_module_tests, m, py::gil_not_used()) {
+PYBIND11_MODULE(pybind11_cross_module_tests, m, py::mod_gil_not_used()) {
     m.doc() = "pybind11 cross-module test module";
 
     // test_local_bindings.py tests:

tests/pybind11_tests.cpp

@@ -75,7 +75,7 @@ const char *cpp_std() {
 #endif
 }
 
-PYBIND11_MODULE(pybind11_tests, m, py::gil_not_used()) {
+PYBIND11_MODULE(pybind11_tests, m, py::mod_gil_not_used()) {
     m.doc() = "pybind11 test module";
 
     // Intentionally kept minimal to not create a maintenance chore

tests/test_cmake_build/main.cpp

@@ -1,6 +1,6 @@
 #include <pybind11/pybind11.h>
 namespace py = pybind11;
 
-PYBIND11_MODULE(test_cmake_build, m, py::gil_not_used()) {
+PYBIND11_MODULE(test_cmake_build, m, py::mod_gil_not_used()) {
     m.def("add", [](int i, int j) { return i + j; });
 }

tests/test_embed/external_module.cpp

@@ -6,7 +6,7 @@ namespace py = pybind11;
  * modules aren't preserved over a finalize/initialize.
  */
 
-PYBIND11_MODULE(external_module, m, py::gil_not_used()) {
+PYBIND11_MODULE(external_module, m, py::mod_gil_not_used()) {
     class A {
     public:
         explicit A(int value) : v{value} {};