text: // Copyright 2016 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "src/heap/array-buffer-tracker.h"
  #include "src/heap/factory.h"
  #include "src/heap/spaces-inl.h"
  #include "src/isolate.h"
  #include "src/objects-inl.h"
  #include "test/cctest/cctest.h"
  #include "test/cctest/heap/heap-tester.h"
  #include "test/cctest/heap/heap-utils.h"
  
  namespace v8 {
  namespace internal {
  namespace heap {
  
  // Tests don't work when --optimize-for-size is set.
  #ifndef V8_LITE_MODE
  
  namespace {
  
  v8::Isolate* NewIsolateForPagePromotion(int min_semi_space_size = 8,
                                          int max_semi_space_size = 8) {
    // Parallel evacuation messes with fragmentation in a way that objects that
    // should be copied in semi space are promoted to old space because of
    // fragmentation.
    FLAG_parallel_compaction = false;
    FLAG_page_promotion = true;
    FLAG_page_promotion_threshold = 0;
    // Parallel scavenge introduces too much fragmentation.
    FLAG_parallel_scavenge = false;
    FLAG_min_semi_space_size = min_semi_space_size;
    // We cannot optimize for size as we require a new space with more than one
    // page.
    FLAG_optimize_for_size = false;
    // Set max_semi_space_size because it could've been initialized by an
    // implication of optimize_for_size.
    FLAG_max_semi_space_size = max_semi_space_size;
    v8::Isolate::CreateParams create_params;
    create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
    v8::Isolate* isolate = v8::Isolate::New(create_params);
    return isolate;
  }
  
  Page* FindLastPageInNewSpace(std::vector<Handle<FixedArray>>& handles) {
    for (auto rit = handles.rbegin(); rit != handles.rend(); ++rit) {
      // One deref gets the Handle, the second deref gets the FixedArray.
      Page* candidate = Page::FromHeapObject(**rit);
      if (candidate->InNewSpace()) return candidate;
    }
    return nullptr;
  }
  
  }  // namespace
  
  UNINITIALIZED_TEST(PagePromotion_NewToOld) {
    if (!i::FLAG_incremental_marking) return;
    if (!i::FLAG_page_promotion) return;
    ManualGCScope manual_gc_scope;
  
    v8::Isolate* isolate = NewIsolateForPagePromotion();
    i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      Heap* heap = i_isolate->heap();
  
      std::vector<Handle<FixedArray>> handles;
      heap::SimulateFullSpace(heap->new_space(), &handles);
      heap->CollectGarbage(NEW_SPACE, i::GarbageCollectionReason::kTesting);
      CHECK_GT(handles.size(), 0u);
      Page* const to_be_promoted_page = FindLastPageInNewSpace(handles);
      CHECK_NOT_NULL(to_be_promoted_page);
      CHECK(!to_be_promoted_page->Contains(heap->new_space()->age_mark()));
      // To perform a sanity check on live bytes we need to mark the heap.
      heap::SimulateIncrementalMarking(heap, true);
      // Sanity check that the page meets the requirements for promotion.
      const int threshold_bytes = static_cast<int>(
          FLAG_page_promotion_threshold *
          MemoryChunkLayout::AllocatableMemoryInDataPage() / 100);
      CHECK_GE(heap->incremental_marking()->marking_state()->live_bytes(
                   to_be_promoted_page),
               threshold_bytes);
  
      // Actual checks: The page is in new space first, but is moved to old space
      // during a full GC.
      CHECK(heap->new_space()->ContainsSlow(to_be_promoted_page->address()));
      CHECK(!heap->old_space()->ContainsSlow(to_be_promoted_page->address()));
      heap::GcAndSweep(heap, OLD_SPACE);
      CHECK(!heap->new_space()->ContainsSlow(to_be_promoted_page->address()));
      CHECK(heap->old_space()->ContainsSlow(to_be_promoted_page->address()));
    }
    isolate->Dispose();
  }
  
  UNINITIALIZED_TEST(PagePromotion_NewToNew) {
    if (!i::FLAG_page_promotion) return;
  
    v8::Isolate* isolate = NewIsolateForPagePromotion();
    Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      Heap* heap = i_isolate->heap();
  
      std::vector<Handle<FixedArray>> handles;
      heap::SimulateFullSpace(heap->new_space(), &handles);
      CHECK_GT(handles.size(), 0u);
      // Last object in handles should definitely be on a page that does not
      // contain the age mark, thus qualifying for moving.
      Handle<FixedArray> last_object = handles.back();
      Page* to_be_promoted_page = Page::FromHeapObject(*last_object);
      CHECK(!to_be_promoted_page->Contains(heap->new_space()->age_mark()));
      CHECK(to_be_promoted_page->Contains(last_object->address()));
      CHECK(heap->new_space()->ToSpaceContainsSlow(last_object->address()));
      heap::GcAndSweep(heap, OLD_SPACE);
      CHECK(heap->new_space()->ToSpaceContainsSlow(last_object->address()));
      CHECK(to_be_promoted_page->Contains(last_object->address()));
    }
    isolate->Dispose();
  }
  
  UNINITIALIZED_TEST(PagePromotion_NewToNewJSArrayBuffer) {
    if (!i::FLAG_page_promotion) return;
  
    // Test makes sure JSArrayBuffer backing stores are still tracked after
    // new-to-new promotion.
    v8::Isolate* isolate = NewIsolateForPagePromotion();
    Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      Heap* heap = i_isolate->heap();
  
      // Fill the current page which potentially contains the age mark.
      heap::FillCurrentPage(heap->new_space());
      // Allocate a buffer we would like to check against.
      Handle<JSArrayBuffer> buffer =
          i_isolate->factory()->NewJSArrayBuffer(SharedFlag::kNotShared);
      CHECK(JSArrayBuffer::SetupAllocatingData(buffer, i_isolate, 100));
      std::vector<Handle<FixedArray>> handles;
      // Simulate a full space, filling the interesting page with live objects.
      heap::SimulateFullSpace(heap->new_space(), &handles);
      CHECK_GT(handles.size(), 0u);
      // First object in handles should be on the same page as the allocated
      // JSArrayBuffer.
      Handle<FixedArray> first_object = handles.front();
      Page* to_be_promoted_page = Page::FromHeapObject(*first_object);
      CHECK(!to_be_promoted_page->Contains(heap->new_space()->age_mark()));
      CHECK(to_be_promoted_page->Contains(first_object->address()));
      CHECK(to_be_promoted_page->Contains(buffer->address()));
      CHECK(heap->new_space()->ToSpaceContainsSlow(first_object->address()));
      CHECK(heap->new_space()->ToSpaceContainsSlow(buffer->address()));
      heap::GcAndSweep(heap, OLD_SPACE);
      CHECK(heap->new_space()->ToSpaceContainsSlow(first_object->address()));
      CHECK(heap->new_space()->ToSpaceContainsSlow(buffer->address()));
      CHECK(to_be_promoted_page->Contains(first_object->address()));
      CHECK(to_be_promoted_page->Contains(buffer->address()));
      CHECK(ArrayBufferTracker::IsTracked(*buffer));
    }
    isolate->Dispose();
  }
  
  UNINITIALIZED_TEST(PagePromotion_NewToOldJSArrayBuffer) {
    if (!i::FLAG_page_promotion) return;
  
    // Test makes sure JSArrayBuffer backing stores are still tracked after
    // new-to-old promotion.
    v8::Isolate* isolate = NewIsolateForPagePromotion();
    Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      Heap* heap = i_isolate->heap();
  
      // Fill the current page which potentially contains the age mark.
      heap::FillCurrentPage(heap->new_space());
      // Allocate a buffer we would like to check against.
      Handle<JSArrayBuffer> buffer =
          i_isolate->factory()->NewJSArrayBuffer(SharedFlag::kNotShared);
      CHECK(JSArrayBuffer::SetupAllocatingData(buffer, i_isolate, 100));
      std::vector<Handle<FixedArray>> handles;
      // Simulate a full space, filling the interesting page with live objects.
      heap::SimulateFullSpace(heap->new_space(), &handles);
      CHECK_GT(handles.size(), 0u);
      // First object in handles should be on the same page as the allocated
      // JSArrayBuffer.
      Handle<FixedArray> first_object = handles.front();
      Page* to_be_promoted_page = Page::FromHeapObject(*first_object);
      CHECK(!to_be_promoted_page->Contains(heap->new_space()->age_mark()));
      CHECK(to_be_promoted_page->Contains(first_object->address()));
      CHECK(to_be_promoted_page->Contains(buffer->address()));
      CHECK(heap->new_space()->ToSpaceContainsSlow(first_object->address()));
      CHECK(heap->new_space()->ToSpaceContainsSlow(buffer->address()));
      heap::GcAndSweep(heap, OLD_SPACE);
      heap::GcAndSweep(heap, OLD_SPACE);
      CHECK(heap->old_space()->ContainsSlow(first_object->address()));
      CHECK(heap->old_space()->ContainsSlow(buffer->address()));
      CHECK(to_be_promoted_page->Contains(first_object->address()));
      CHECK(to_be_promoted_page->Contains(buffer->address()));
      CHECK(ArrayBufferTracker::IsTracked(*buffer));
    }
    isolate->Dispose();
  }
  
  UNINITIALIZED_HEAP_TEST(Regress658718) {
    if (!i::FLAG_page_promotion) return;
  
    v8::Isolate* isolate = NewIsolateForPagePromotion(4, 8);
    Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      Heap* heap = i_isolate->heap();
      heap->delay_sweeper_tasks_for_testing_ = true;
      heap->new_space()->Grow();
      {
        v8::HandleScope inner_handle_scope(isolate);
        std::vector<Handle<FixedArray>> handles;
        heap::SimulateFullSpace(heap->new_space(), &handles);
        CHECK_GT(handles.size(), 0u);
        // Last object in handles should definitely be on a page that does not
        // contain the age mark, thus qualifying for moving.
        Handle<FixedArray> last_object = handles.back();
        Page* to_be_promoted_page = Page::FromHeapObject(*last_object);
        CHECK(!to_be_promoted_page->Contains(heap->new_space()->age_mark()));
        CHECK(to_be_promoted_page->Contains(last_object->address()));
        CHECK(heap->new_space()->ToSpaceContainsSlow(last_object->address()));
        heap->CollectGarbage(OLD_SPACE, i::GarbageCollectionReason::kTesting);
        CHECK(heap->new_space()->ToSpaceContainsSlow(last_object->address()));
        CHECK(to_be_promoted_page->Contains(last_object->address()));
      }
      heap->CollectGarbage(NEW_SPACE, i::GarbageCollectionReason::kTesting);
      heap->new_space()->Shrink();
      heap->memory_allocator()->unmapper()->EnsureUnmappingCompleted();
      heap->delay_sweeper_tasks_for_testing_ = false;
      heap->mark_compact_collector()->sweeper()->StartSweeperTasks();
      heap->mark_compact_collector()->EnsureSweepingCompleted();
    }
    isolate->Dispose();
  }
  
  #endif  // V8_LITE_MODE
  
  }  // namespace heap
  }  // namespace internal
  }  // namespace v8
  