Make new space allocation throughput estimation more accurate.

test/cctest/test-heap.cc

Index: test/cctest/test-heap.cc
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index d8c89aec1b4b242a9702c3a018681bdb9b2569bc..fc35221932fe18b63948f5b0c0111213c5bac764 100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -5430,3 +5430,67 @@ TEST(PreprocessStackTrace) {
     CHECK(!element->IsCode());
   }
 }
+
+
+void AllocateInNewSpace(Isolate* isolate, size_t bytes) {
+  CHECK(bytes >= FixedArray::kHeaderSize);
+  CHECK(bytes % kPointerSize == 0);
+  Factory* factory = isolate->factory();
+  HandleScope scope(isolate);
+  AlwaysAllocateScope always_allocate(isolate);
+  int elements =
+      static_cast<int>((bytes - FixedArray::kHeaderSize) / kPointerSize);
+  Handle<FixedArray> array = factory->NewFixedArray(elements, NOT_TENURED);
+  CHECK(isolate->heap()->InNewSpace(*array));
+  CHECK_EQ(bytes, array->Size());
+}
+
+
+TEST(NewSpaceAllocationCounter) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  size_t counter1 = heap->NewSpaceAllocationCounter();
+  heap->CollectGarbage(NEW_SPACE);
+  const size_t kSize = 1024;
+  AllocateInNewSpace(isolate, kSize);
+  size_t counter2 = heap->NewSpaceAllocationCounter();
+  CHECK_EQ(kSize, counter2 - counter1);
+  heap->CollectGarbage(NEW_SPACE);
+  size_t counter3 = heap->NewSpaceAllocationCounter();
+  CHECK_EQ(0, counter3 - counter2);
+  // Test counter overflow.
+  size_t max_counter = -1;
+  heap->set_new_space_allocation_counter(max_counter - 10 * kSize);
+  size_t start = heap->NewSpaceAllocationCounter();
+  for (int i = 0; i < 20; i++) {
+    AllocateInNewSpace(isolate, kSize);
+    size_t counter = heap->NewSpaceAllocationCounter();
+    CHECK_EQ(kSize, counter - start);
+    start = counter;
+  }
+}
+
+
+TEST(NewSpaceAllocationThroughput) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  GCTracer* tracer = heap->tracer();
+  int time1 = 100;
+  size_t counter1 = 1000;
+  tracer->SampleNewSpaceAllocation(time1, counter1);
+  int time2 = 200;
+  size_t counter2 = 2000;
+  tracer->SampleNewSpaceAllocation(time2, counter2);
+  size_t throughput =
+      tracer->NewSpaceAllocationThroughputInBytesPerMillisecond();
+  CHECK_EQ((counter2 - counter1) / (time2 - time1), throughput);
+  int time3 = 1000;
+  size_t counter3 = 30000;
+  tracer->SampleNewSpaceAllocation(time3, counter3);
+  throughput = tracer->NewSpaceAllocationThroughputInBytesPerMillisecond();
+  CHECK_EQ((counter3 - counter1) / (time3 - time1), throughput);
+}