feat(gobject, closure): wrap GObject with GC-able C++ wrapper to fix closures reference loop

src/boxed.cc

@@ -438,7 +438,7 @@ Local<Value> WrapperFromBoxed(GIBaseInfo *info, void *data, ResourceOwnership ow
     return instance.ToLocalChecked();
 }
 
-void* PointerFromWrapper(Local<Value> value) {
+void* BoxedFromWrapper(Local<Value> value) {
     Local<Object> object = TO_OBJECT (value);
     g_assert(object->InternalFieldCount() > 0);
     void *boxed = object->GetAlignedPointerFromInternalField(0);

src/boxed.h

@@ -32,6 +32,6 @@ class Boxed {
 Local<Function>         MakeBoxedClass   (GIBaseInfo *info);
 Local<FunctionTemplate> GetBoxedTemplate (GIBaseInfo *info, GType gtype);
 Local<Value>            WrapperFromBoxed (GIBaseInfo *info, void *data, ResourceOwnership ownership = kNone);
-void *                  PointerFromWrapper (Local<Value>);
+void *                  BoxedFromWrapper (Local<Value>);
 
 };

src/closure.cc

@@ -15,13 +15,13 @@ using v8::Isolate;
 using v8::Local;
 using v8::Object;
 using v8::Value;
-using Nan::Persistent;
 
 namespace GNodeJS {
 
 GClosure *Closure::New (Local<Function> function, GICallableInfo* info, guint signalId) {
     Closure *closure = (Closure *) g_closure_new_simple (sizeof (*closure), GUINT_TO_POINTER(signalId));
-    closure->persistent.Reset(function);
+    closure->isolate = function->GetIsolate();
+    closure->functionRef.Reset(closure->isolate, function);
     if (info) {
         closure->info = g_base_info_ref(info);
     } else {
@@ -34,11 +34,12 @@ GClosure *Closure::New (Local<Function> function, GICallableInfo* info, guint si
 }
 
 void Closure::Execute(GICallableInfo *info, guint signal_id,
-                      const Nan::Persistent<v8::Function> &persFn,
+                      v8::Isolate *isolate,
+                      const v8::TracedReference<v8::Function> &fnRef,
                       GValue *g_return_value, guint n_param_values,
                       const GValue *param_values) {
     Nan::HandleScope scope;
-    auto func = Nan::New<Function>(persFn);
+    auto func = fnRef.Get(isolate);
 
     GSignalQuery signal_query = { 0, };
 
@@ -139,11 +140,25 @@ void Closure::Marshal(GClosure     *base,
 
     if (env->IsSameThread()) {
         /* Case 1: same thread */
-        Closure::Execute(closure->info, signal_id, closure->persistent, g_return_value, n_param_values, param_values);
+        Closure::Execute(
+            closure->info,
+            signal_id,
+            closure->isolate,
+            closure->functionRef,
+            g_return_value,
+            n_param_values,
+            param_values);
     } else {
         /* Case 2: different thread */
         env->Call([&]() {
-            Closure::Execute(closure->info, signal_id, closure->persistent, g_return_value, n_param_values, param_values);
+            Closure::Execute(
+                closure->info,
+                signal_id,
+                closure->isolate,
+                closure->functionRef,
+                g_return_value,
+                n_param_values,
+                param_values);
         });
     }
 }

src/closure.h

@@ -16,11 +16,12 @@ namespace GNodeJS {
 
 struct Closure {
     GClosure base;
-    Nan::Persistent<v8::Function> persistent;
+    v8::Isolate *isolate;
+    v8::TracedReference<v8::Function> functionRef;
     GICallableInfo* info;
 
     ~Closure() {
-        persistent.Reset();
+        functionRef.Reset();
         if (info) g_base_info_unref (info);
     }
 
@@ -29,7 +30,8 @@ struct Closure {
                          guint signalId);
 
     static void Execute(GICallableInfo *info, guint signal_id,
-                        const Nan::Persistent<v8::Function> &persFn,
+                        v8::Isolate *isolate,
+                        const v8::TracedReference<v8::Function> &persFn,
                         GValue *g_return_value, guint n_param_values,
                         const GValue *param_values);
 

src/function.cc

@@ -553,6 +553,14 @@ Local<Value> FunctionCall (
     return jsReturnValue;
 }
 
+static void* PointerFromWrapper(Local<Value> value) {
+    /* FIXME: find a better way to do this. */
+    if (ValueIsInstanceOfGType(value, G_TYPE_OBJECT)) {
+        return GObjectFromWrapper(value);
+    } else {
+        return BoxedFromWrapper(value);
+    }
+}
 
 /**
  * Creates the JS return value from the C arguments list

src/gi.cc

@@ -121,7 +121,7 @@ NAN_METHOD(Bootstrap) {
 }
 
 NAN_METHOD(GetConstantValue) {
-    GIBaseInfo *gi_info = (GIBaseInfo *) GNodeJS::PointerFromWrapper (info[0]);
+    GIBaseInfo *gi_info = (GIBaseInfo *) GNodeJS::BoxedFromWrapper (info[0]);
     GITypeInfo *type_info = g_constant_info_get_type(gi_info);
 
     if (type_info == NULL) {
@@ -213,8 +213,8 @@ NAN_METHOD(StructFieldSetter) {
     Local<Object> fieldInfo    = info[1].As<Object>();
     Local<Value>  value        = info[2];
 
-    void        *boxed = GNodeJS::PointerFromWrapper(boxedWrapper);
-    GIFieldInfo *field = (GIFieldInfo *) GNodeJS::PointerFromWrapper(fieldInfo);
+    void        *boxed = GNodeJS::BoxedFromWrapper(boxedWrapper);
+    GIFieldInfo *field = (GIFieldInfo *) GNodeJS::BoxedFromWrapper(fieldInfo);
     GITypeInfo  *field_type = g_field_info_get_type(field);
 
     g_assert(boxed);
@@ -267,10 +267,10 @@ NAN_METHOD(StructFieldGetter) {
         return;
     }
 
-    auto boxed = GNodeJS::PointerFromWrapper(jsBoxed);
+    auto boxed = GNodeJS::BoxedFromWrapper(jsBoxed);
     // ref it because the unwrapped ref belongs to the JS wrapper
     BaseInfo fieldInfo =
-        g_base_info_ref((GIFieldInfo *) GNodeJS::PointerFromWrapper(jsFieldInfo));
+        g_base_info_ref((GIFieldInfo *) GNodeJS::BoxedFromWrapper(jsFieldInfo));
 
     if (boxed == NULL) {
         Nan::ThrowError("StructFieldGetter: instance is NULL");
@@ -320,7 +320,7 @@ NAN_METHOD(GetBaseClass) {
 }
 
 NAN_METHOD(GetTypeSize) {
-    GITypeInfo *gi_info = (GITypeInfo *) GNodeJS::PointerFromWrapper (info[0]);
+    GITypeInfo *gi_info = (GITypeInfo *) GNodeJS::BoxedFromWrapper (info[0]);
     auto size = GNodeJS::GetTypeSize (gi_info);
     info.GetReturnValue().Set(Nan::New<Number>(size));
 }

src/gi.h

@@ -55,7 +55,7 @@ class BaseInfo {
     BaseInfo (Local<Value> value) {
         Local<Object> object = value.As<Object>();
         _info = g_base_info_ref(
-            (GIBaseInfo *) GNodeJS::PointerFromWrapper(object));
+            (GIBaseInfo *) GNodeJS::BoxedFromWrapper(object));
     };
 
     ~BaseInfo () {