Modernize atomics

- Based on C++11's `atomic`
- Reworked `SafeRefCount` (based on the rewrite by @hpvb)
- Replaced free atomic functions by the new `SafeNumeric<T>`
- Replaced wrong cases of `volatile bool` by the new `SafeFlag`
- Platform-specific implementations no longer needed

Co-authored-by: Hein-Pieter van Braam-Stewart <hp@tmm.cx>

2 files changed, 5 insertions, 4 deletions

diff --git a/modules/gdnative/nativescript/nativescript.cpp b/modules/gdnative/nativescript/nativescript.cpp
index 64fb8ee9c7..1bdbb0b03b 100644
--- a/modules/gdnative/nativescript/nativescript.cpp
+++ b/modules/gdnative/nativescript/nativescript.cpp
@@ -1670,7 +1670,7 @@ void NativeScriptLanguage::defer_init_library(Ref<GDNativeLibrary> lib, NativeSc
 	MutexLock lock(mutex);
 	libs_to_init.insert(lib);
 	scripts_to_register.insert(script);
-	has_objects_to_register = true;
+	has_objects_to_register.set();
 }
 #endif
 
@@ -1759,7 +1759,7 @@ void NativeScriptLanguage::call_libraries_cb(const StringName &name) {
 
 void NativeScriptLanguage::frame() {
 #ifndef NO_THREADS
-	if (has_objects_to_register) {
+	if (has_objects_to_register.is_set()) {
 		MutexLock lock(mutex);
 		for (Set<Ref<GDNativeLibrary>>::Element *L = libs_to_init.front(); L; L = L->next()) {
 			init_library(L->get());
@@ -1769,7 +1769,7 @@ void NativeScriptLanguage::frame() {
 			register_script(S->get());
 		}
 		scripts_to_register.clear();
-		has_objects_to_register = false;
+		has_objects_to_register.clear();
 	}
 #endif
 
diff --git a/modules/gdnative/nativescript/nativescript.h b/modules/gdnative/nativescript/nativescript.h
index 81a158d09b..d6ba2bbec1 100644
--- a/modules/gdnative/nativescript/nativescript.h
+++ b/modules/gdnative/nativescript/nativescript.h
@@ -40,6 +40,7 @@
 #include "core/os/thread_safe.h"
 #include "core/templates/oa_hash_map.h"
 #include "core/templates/ordered_hash_map.h"
+#include "core/templates/safe_refcount.h"
 #include "core/templates/self_list.h"
 #include "scene/main/node.h"
 
@@ -262,7 +263,7 @@ private:
 #ifndef NO_THREADS
 	Set<Ref<GDNativeLibrary>> libs_to_init;
 	Set<NativeScript *> scripts_to_register;
-	volatile bool has_objects_to_register = false; // so that we don't lock mutex every frame - it's rarely needed
+	SafeFlag has_objects_to_register; // so that we don't lock mutex every frame - it's rarely needed
 	void defer_init_library(Ref<GDNativeLibrary> lib, NativeScript *script);
 #endif