[heap] Reland "Remove black pages and use black areas instead."

test/cctest/heap/test-heap.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 6769 matching lines @@
     }
   }
   CHECK(marking->IsComplete());
   intptr_t size_before = heap->SizeOfObjects();
   CcTest::heap()->CollectAllGarbage();
   intptr_t size_after = heap->SizeOfObjects();
   // Live size does not increase after garbage collection.
   CHECK_LE(size_after, size_before);
 }
 
+TEST(LeftTrimFixedArrayInBlackArea) {
+  FLAG_black_allocation = true;
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Heap* heap = CcTest::heap();
+  Isolate* isolate = heap->isolate();
+  heap->CollectAllGarbage();
+
+  i::MarkCompactCollector* collector = heap->mark_compact_collector();
+  i::IncrementalMarking* marking = heap->incremental_marking();
+  if (collector->sweeping_in_progress()) {
+    collector->EnsureSweepingCompleted();
+  }
+  CHECK(marking->IsMarking() || marking->IsStopped());
+  if (marking->IsStopped()) {
+    heap->StartIncrementalMarking();
+  }
+  CHECK(marking->IsMarking());
+  marking->StartBlackAllocationForTesting();
+
+  // Ensure that we allocate a new page, set up a bump pointer area, and
+  // perform the allocation in a black area.
+  heap::SimulateFullSpace(heap->old_space());
+  isolate->factory()->NewFixedArray(4, TENURED);
+  Handle<FixedArray> array = isolate->factory()->NewFixedArray(50, TENURED);
+  CHECK(heap->old_space()->Contains(*array));
+  CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
+
+  // Now left trim the allocated black area. A filler has to be installed
+  // for the trimmed area and all mark bits of the trimmed area have to be
+  // cleared.
+  FixedArrayBase* trimmed = heap->LeftTrimFixedArray(*array, 10);
+  CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
+
+  heap::GcAndSweep(heap, OLD_SPACE);
+}
+
 TEST(Regress618958) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
   Heap* heap = CcTest::heap();
   bool isolate_is_locked = true;
   heap->update_external_memory(100 * MB);
   int mark_sweep_count_before = heap->ms_count();
   heap->MemoryPressureNotification(MemoryPressureLevel::kCritical,
                                    isolate_is_locked);
   int mark_sweep_count_after = heap->ms_count();
@@ skipping 86 matching lines @@
       chunk, chunk->area_end() - kPointerSize, chunk->area_end());
   slots[chunk->area_end() - kPointerSize] = false;
   RememberedSet<OLD_TO_NEW>::Iterate(chunk, [&slots](Address addr) {
     CHECK(slots[addr]);
     return KEEP_SLOT;
   });
 }
 
 }  // namespace internal
 }  // namespace v8