Enable calling the SetReference* & SetObjectGroupId functions with a Persistent<SubclassOfValue>.

This is needed for https://codereview.chromium.org/26792002/

BUG=
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/27512003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17253 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -712,6 +712,7 @@ template <class T, class M> class Persistent {
   V8_INLINE T* operator*() const { return val_; }
 
  private:
+  friend class Isolate;
   friend class Utils;
   template<class F> friend class Handle;
   template<class F> friend class Local;
@@ -4066,7 +4067,7 @@ class V8_EXPORT Isolate {
    * garbage collection types it is sufficient to provide object groups
    * for partially dependent handles only.
    */
-  void SetObjectGroupId(const Persistent<Value>& object,
+  template<typename T> void SetObjectGroupId(const Persistent<T>& object,
                                              UniqueId id);
 
   /**
@@ -4076,8 +4077,8 @@ class V8_EXPORT Isolate {
    * are removed. It is intended to be used in the before-garbage-collection
    * callback function.
    */
-  void SetReferenceFromGroup(UniqueId id,
-                             const Persistent<Value>& child);
+  template<typename T> void SetReferenceFromGroup(UniqueId id,
+                                                  const Persistent<T>& child);
 
   /**
    * Allows the host application to declare implicit references from an object
@@ -4085,8 +4086,8 @@ class V8_EXPORT Isolate {
    * too. After each garbage collection, all implicit references are removed. It
    * is intended to be used in the before-garbage-collection callback function.
    */
-  void SetReference(const Persistent<Object>& parent,
-                    const Persistent<Value>& child);
+  template<typename T, typename S>
+  void SetReference(const Persistent<T>& parent, const Persistent<S>& child);
 
   typedef void (*GCPrologueCallback)(Isolate* isolate,
                                      GCType type,
@@ -4140,8 +4141,11 @@ class V8_EXPORT Isolate {
   Isolate& operator=(const Isolate&);
   void* operator new(size_t size);
   void operator delete(void*, size_t);
-};
 
+  void SetObjectGroupId(internal::Object** object, UniqueId id);
+  void SetReferenceFromGroup(UniqueId id, internal::Object** object);
+  void SetReference(internal::Object** parent, internal::Object** child);
+};
 
 class V8_EXPORT StartupData {
  public:
@@ -6420,6 +6424,33 @@ void* Isolate::GetData() {
 }
 
 
+template<typename T>
+void Isolate::SetObjectGroupId(const Persistent<T>& object,
+                               UniqueId id) {
+  TYPE_CHECK(Value, T);
+  SetObjectGroupId(reinterpret_cast<v8::internal::Object**>(object.val_), id);
+}
+
+
+template<typename T>
+void Isolate::SetReferenceFromGroup(UniqueId id,
+                                    const Persistent<T>& object) {
+  TYPE_CHECK(Value, T);
+  SetReferenceFromGroup(id,
+                        reinterpret_cast<v8::internal::Object**>(object.val_));
+}
+
+
+template<typename T, typename S>
+void Isolate::SetReference(const Persistent<T>& parent,
+                           const Persistent<S>& child) {
+  TYPE_CHECK(Object, T);
+  TYPE_CHECK(Value, S);
+  SetReference(reinterpret_cast<v8::internal::Object**>(parent.val_),
+               reinterpret_cast<v8::internal::Object**>(child.val_));
+}
+
+
 Local<Value> Context::GetEmbedderData(int index) {
 #ifndef V8_ENABLE_CHECKS
   typedef internal::Object O;

src/api.cc

@@ -6350,31 +6350,32 @@ v8::Local<Value> Isolate::ThrowException(v8::Local<v8::Value> value) {
 }
 
 
-void Isolate::SetObjectGroupId(const Persistent<Value>& object,
-                               UniqueId id) {
+void Isolate::SetObjectGroupId(internal::Object** object, UniqueId id) {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(this);
   internal_isolate->global_handles()->SetObjectGroupId(
-      Utils::OpenPersistent(object).location(),
+      v8::internal::Handle<v8::internal::Object>(object).location(),
       id);
+  internal_isolate->global_handles()->SetObjectGroupId(object, id);
 }
 
 
-void Isolate::SetReferenceFromGroup(UniqueId id,
-                                    const Persistent<Value>& object) {
+void Isolate::SetReferenceFromGroup(UniqueId id, internal::Object** object) {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(this);
   internal_isolate->global_handles()->SetReferenceFromGroup(
       id,
-      Utils::OpenPersistent(object).location());
+      v8::internal::Handle<v8::internal::Object>(object).location());
+  internal_isolate->global_handles()->SetReferenceFromGroup(id, object);
 }
 
 
-void Isolate::SetReference(const Persistent<Object>& parent,
-                           const Persistent<Value>& child) {
+void Isolate::SetReference(internal::Object** parent,
+                           internal::Object** child) {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(this);
-  i::Object** parent_location = Utils::OpenPersistent(parent).location();
+  i::Object** parent_location =
+      v8::internal::Handle<v8::internal::Object>(parent).location();
   internal_isolate->global_handles()->SetReference(
       reinterpret_cast<i::HeapObject**>(parent_location),
-      Utils::OpenPersistent(child).location());
+      v8::internal::Handle<v8::internal::Object>(child).location());
 }
 
 

test/cctest/test-api.cc

@@ -3318,8 +3318,9 @@ class WeakCallCounter {
 };
 
 
+template<typename T>
 static void WeakPointerCallback(v8::Isolate* isolate,
-                                Persistent<Value>* handle,
+                                Persistent<T>* handle,
                                 WeakCallCounter* counter) {
   CHECK_EQ(1234, counter->id());
   counter->increment();
@@ -3327,7 +3328,8 @@ static void WeakPointerCallback(v8::Isolate* isolate,
 }
 
 
-static UniqueId MakeUniqueId(const Persistent<Value>& p) {
+template<typename T>
+static UniqueId MakeUniqueId(const Persistent<T>& p) {
   return UniqueId(reinterpret_cast<uintptr_t>(*v8::Utils::OpenPersistent(p)));
 }
 
@@ -3425,6 +3427,97 @@ THREADED_TEST(ApiObjectGroups) {
 }
 
 
+THREADED_TEST(ApiObjectGroupsForSubtypes) {
+  LocalContext env;
+  v8::Isolate* iso = env->GetIsolate();
+  HandleScope scope(iso);
+
+  Persistent<Object> g1s1;
+  Persistent<String> g1s2;
+  Persistent<String> g1c1;
+  Persistent<Object> g2s1;
+  Persistent<String> g2s2;
+  Persistent<String> g2c1;
+
+  WeakCallCounter counter(1234);
+
+  {
+    HandleScope scope(iso);
+    g1s1.Reset(iso, Object::New());
+    g1s2.Reset(iso, String::New("foo1"));
+    g1c1.Reset(iso, String::New("foo2"));
+    g1s1.MakeWeak(&counter, &WeakPointerCallback);
+    g1s2.MakeWeak(&counter, &WeakPointerCallback);
+    g1c1.MakeWeak(&counter, &WeakPointerCallback);
+
+    g2s1.Reset(iso, Object::New());
+    g2s2.Reset(iso, String::New("foo3"));
+    g2c1.Reset(iso, String::New("foo4"));
+    g2s1.MakeWeak(&counter, &WeakPointerCallback);
+    g2s2.MakeWeak(&counter, &WeakPointerCallback);
+    g2c1.MakeWeak(&counter, &WeakPointerCallback);
+  }
+
+  Persistent<Value> root(iso, g1s1);  // make a root.
+
+  // Connect group 1 and 2, make a cycle.
+  {
+    HandleScope scope(iso);
+    CHECK(Local<Object>::New(iso, g1s1)->Set(0, Local<Object>::New(iso, g2s1)));
+    CHECK(Local<Object>::New(iso, g2s1)->Set(0, Local<Object>::New(iso, g1s1)));
+  }
+
+  {
+    UniqueId id1 = MakeUniqueId(g1s1);
+    UniqueId id2 = MakeUniqueId(g2s2);
+    iso->SetObjectGroupId(g1s1, id1);
+    iso->SetObjectGroupId(g1s2, id1);
+    iso->SetReference(g1s1, g1c1);
+    iso->SetObjectGroupId(g2s1, id2);
+    iso->SetObjectGroupId(g2s2, id2);
+    iso->SetReferenceFromGroup(id2, g2c1);
+  }
+  // Do a single full GC, ensure incremental marking is stopped.
+  v8::internal::Heap* heap = reinterpret_cast<v8::internal::Isolate*>(
+      iso)->heap();
+  heap->CollectAllGarbage(i::Heap::kAbortIncrementalMarkingMask);
+
+  // All object should be alive.
+  CHECK_EQ(0, counter.NumberOfWeakCalls());
+
+  // Weaken the root.
+  root.MakeWeak(&counter, &WeakPointerCallback);
+  // But make children strong roots---all the objects (except for children)
+  // should be collectable now.
+  g1c1.ClearWeak();
+  g2c1.ClearWeak();
+
+  // Groups are deleted, rebuild groups.
+  {
+    UniqueId id1 = MakeUniqueId(g1s1);
+    UniqueId id2 = MakeUniqueId(g2s2);
+    iso->SetObjectGroupId(g1s1, id1);
+    iso->SetObjectGroupId(g1s2, id1);
+    iso->SetReference(g1s1, g1c1);
+    iso->SetObjectGroupId(g2s1, id2);
+    iso->SetObjectGroupId(g2s2, id2);
+    iso->SetReferenceFromGroup(id2, g2c1);
+  }
+
+  heap->CollectAllGarbage(i::Heap::kAbortIncrementalMarkingMask);
+
+  // All objects should be gone. 5 global handles in total.
+  CHECK_EQ(5, counter.NumberOfWeakCalls());
+
+  // And now make children weak again and collect them.
+  g1c1.MakeWeak(&counter, &WeakPointerCallback);
+  g2c1.MakeWeak(&counter, &WeakPointerCallback);
+
+  heap->CollectAllGarbage(i::Heap::kAbortIncrementalMarkingMask);
+  CHECK_EQ(7, counter.NumberOfWeakCalls());
+}
+
+
 THREADED_TEST(ApiObjectGroupsCycle) {
   LocalContext env;
   v8::Isolate* iso = env->GetIsolate();