Debug garbage collector does not correctly remove cross-gen garbage

runtime/vm/heap_test.cc

Index: runtime/vm/heap_test.cc
diff --git a/runtime/vm/heap_test.cc b/runtime/vm/heap_test.cc
index b594807cf850a2517afe6b10f50ed664c22c5e3d..8c616d3f01fb35552cdc0e09937eb90ee4dc286c 100644
--- a/runtime/vm/heap_test.cc
+++ b/runtime/vm/heap_test.cc
@@ -363,4 +363,212 @@ ISOLATE_UNIT_TEST_CASE(BecomeForwardRememberedObject) {
   EXPECT(before_obj.raw() == after_obj.raw());
 }
 
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_DeadOldToNew) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  old.SetAt(0, neu);
+  old = Array::null();
+  neu = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before == size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_DeadNewToOld) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  neu.SetAt(0, old);
+  old = Array::null();
+  neu = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before == size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_DeadGenCycle) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  neu.SetAt(0, old);
+  old.SetAt(0, neu);
+  old = Array::null();
+  neu = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before == size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_LiveNewToOld) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  neu.SetAt(0, old);
+  old = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before < size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_LiveOldToNew) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  old.SetAt(0, neu);
+  neu = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before < size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_LiveOldDeadNew) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  neu = Array::null();
+  old.SetAt(0, old);
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before < size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_LiveNewDeadOld) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  old = Array::null();
+  neu.SetAt(0, neu);
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before < size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_LiveNewToOldChain) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& old2 = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  old.SetAt(0, old2);
+  neu.SetAt(0, old);
+  old = Array::null();
+  old2 = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before < size_after);
+}
+
+
+ISOLATE_UNIT_TEST_CASE(CollectAllGarbage_LiveOldToNewChain) {
+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+
+  heap->CollectAllGarbage();
+  intptr_t size_before =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  Array& old = Array::Handle(Array::New(1, Heap::kOld));
+  Array& neu = Array::Handle(Array::New(1, Heap::kNew));
+  Array& neu2 = Array::Handle(Array::New(1, Heap::kOld));
+  neu.SetAt(0, neu2);
+  old.SetAt(0, neu);
+  neu = Array::null();
+  neu2 = Array::null();
+
+  heap->CollectAllGarbage();
+
+  intptr_t size_after =
+      heap->new_space()->UsedInWords() + heap->old_space()->UsedInWords();
+
+  EXPECT(size_before < size_after);
+}
+
 }  // namespace dart