New GC related APIs: Implicit references.

test/cctest/test-mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 352 matching lines @@
   {
     Object** g1_objects[] = { g1s1.location(), g1s2.location() };
     Object** g1_children[] = { g1c1.location() };
     Object** g2_objects[] = { g2s1.location(), g2s2.location() };
     Object** g2_children[] = { g2c1.location() };
     global_handles->AddObjectGroup(g1_objects, 2, NULL);
     global_handles->AddImplicitReferences(
         Handle<HeapObject>::cast(g1s1).location(), g1_children, 1);
     global_handles->AddObjectGroup(g2_objects, 2, NULL);
     global_handles->AddImplicitReferences(
-        Handle<HeapObject>::cast(g2s2).location(), g2_children, 1);
+        Handle<HeapObject>::cast(g2s1).location(), g2_children, 1);
   }
   // Do a full GC
   HEAP->CollectGarbage(OLD_POINTER_SPACE);
 
   // All object should be alive.
   CHECK_EQ(0, NumberOfWeakCalls);
 
   // Weaken the root.
   global_handles->MakeWeak(root.location(),
                            reinterpret_cast<void*>(1234),
                            NULL,
                            &WeakPointerCallback);
   // But make children strong roots---all the objects (except for children)
   // should be collectable now.
   global_handles->ClearWeakness(g1c1.location());
   global_handles->ClearWeakness(g2c1.location());
 
   // Groups are deleted, rebuild groups.
   {
     Object** g1_objects[] = { g1s1.location(), g1s2.location() };
     Object** g1_children[] = { g1c1.location() };
     Object** g2_objects[] = { g2s1.location(), g2s2.location() };
     Object** g2_children[] = { g2c1.location() };
     global_handles->AddObjectGroup(g1_objects, 2, NULL);
     global_handles->AddImplicitReferences(
         Handle<HeapObject>::cast(g1s1).location(), g1_children, 1);
     global_handles->AddObjectGroup(g2_objects, 2, NULL);
     global_handles->AddImplicitReferences(
-        Handle<HeapObject>::cast(g2s2).location(), g2_children, 1);
+        Handle<HeapObject>::cast(g2s1).location(), g2_children, 1);
   }
 
   HEAP->CollectGarbage(OLD_POINTER_SPACE);
 
   // All objects should be gone. 5 global handles in total.
   CHECK_EQ(5, NumberOfWeakCalls);
 
   // And now make children weak again and collect them.
   global_handles->MakeWeak(g1c1.location(),
                            reinterpret_cast<void*>(1234),
@@ skipping 57 matching lines @@
                            NULL,
                            &WeakPointerCallback);
 
   Handle<Object> root = global_handles->Create(*g1s1);  // make a root.
 
   // Connect group 1 and 2, make a cycle.
   Handle<FixedArray>::cast(g1s2)->set(0, *g2s2);
   Handle<FixedArray>::cast(g2s1)->set(0, *g1s1);
 
   {
-    Object** g1_children[] = { g1c1.location() };
-    Object** g2_children[] = { g2c1.location() };
     global_handles->SetObjectGroupId(g1s1.location(), v8::UniqueId(1));
     global_handles->SetObjectGroupId(g1s2.location(), v8::UniqueId(1));
-    global_handles->AddImplicitReferences(
-        Handle<HeapObject>::cast(g1s1).location(), g1_children, 1);
+    global_handles->SetObjectGroupRepresentative(
+        v8::UniqueId(1), reinterpret_cast<HeapObject**>(g1s1.location()));
+    global_handles->AddImplicitReference(v8::UniqueId(1), g1c1.location());
     global_handles->SetObjectGroupId(g2s1.location(), v8::UniqueId(2));
     global_handles->SetObjectGroupId(g2s2.location(), v8::UniqueId(2));
-    global_handles->AddImplicitReferences(
-        Handle<HeapObject>::cast(g2s2).location(), g2_children, 1);
+    global_handles->SetObjectGroupRepresentative(
+        v8::UniqueId(2), reinterpret_cast<HeapObject**>(g2s1.location()));
+    global_handles->AddImplicitReference(v8::UniqueId(2), g2c1.location());
   }
   // Do a full GC
   heap->CollectGarbage(OLD_POINTER_SPACE);
 
   // All object should be alive.
   CHECK_EQ(0, NumberOfWeakCalls);
 
   // Weaken the root.
   global_handles->MakeWeak(root.location(),
                            reinterpret_cast<void*>(1234),
                            NULL,
                            &WeakPointerCallback);
   // But make children strong roots---all the objects (except for children)
   // should be collectable now.
   global_handles->ClearWeakness(g1c1.location());
   global_handles->ClearWeakness(g2c1.location());
 
   // Groups are deleted, rebuild groups.
   {
-    Object** g1_children[] = { g1c1.location() };
-    Object** g2_children[] = { g2c1.location() };
     global_handles->SetObjectGroupId(g1s1.location(), v8::UniqueId(1));
     global_handles->SetObjectGroupId(g1s2.location(), v8::UniqueId(1));
-    global_handles->AddImplicitReferences(
-        Handle<HeapObject>::cast(g1s1).location(), g1_children, 1);
+    global_handles->SetObjectGroupRepresentative(
+        v8::UniqueId(1), reinterpret_cast<HeapObject**>(g1s1.location()));
+    global_handles->AddImplicitReference(v8::UniqueId(1), g1c1.location());
     global_handles->SetObjectGroupId(g2s1.location(), v8::UniqueId(2));
     global_handles->SetObjectGroupId(g2s2.location(), v8::UniqueId(2));
-    global_handles->AddImplicitReferences(
-        Handle<HeapObject>::cast(g2s2).location(), g2_children, 1);
+    global_handles->SetObjectGroupRepresentative(
+        v8::UniqueId(2), reinterpret_cast<HeapObject**>(g2s1.location()));
+    global_handles->AddImplicitReference(v8::UniqueId(2), g2c1.location());
   }
 
   heap->CollectGarbage(OLD_POINTER_SPACE);
 
   // All objects should be gone. 5 global handles in total.
   CHECK_EQ(5, NumberOfWeakCalls);
 
   // And now make children weak again and collect them.
   global_handles->MakeWeak(g1c1.location(),
                            reinterpret_cast<void*>(1234),
@@ skipping 147 matching lines @@
       if (v8::internal::Snapshot::IsEnabled()) {
         CHECK_LE(delta, 2900 * 1024);
       } else {
         CHECK_LE(delta, 3400 * 1024);
       }
     }
   }
 }
 
 #endif  // __linux__ and !USE_SIMULATOR