Debug garbage collector does not correctly remove cross-gen garbage

runtime/vm/heap_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 
 #include "platform/assert.h"
 #include "vm/become.h"
 #include "vm/dart_api_impl.h"
 #include "vm/globals.h"
@@ skipping 344 matching lines @@
 
   Become::ElementsForwardIdentity(before, after);
 
   EXPECT(before_obj.raw() == after_obj.raw());
   EXPECT(!after_obj.raw()->IsRemembered());
 
   heap->CollectAllGarbage();
 
   EXPECT(before_obj.raw() == after_obj.raw());
 }
 

[rmacnak, 2017/06/19 19:29:00]

Two lines between functions in cc files.

+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