Compute the heap growing factor based on mutator utilization and allocation throughput.

test/unittests/heap/heap-unittest.cc

+// Copyright 2014 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 <cmath>
+#include <limits>
+
+#include "src/objects.h"
+#include "src/objects-inl.h"
+
+#include "src/handles.h"
+#include "src/handles-inl.h"
+
+#include "src/heap/heap.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace internal {
+
+double Round(double x) {
+  // Round to three digits.
+  return floor(x * 1000 + 0.5) / 1000;
+}
+
+
+void CheckEqualRounded(double expected, double actual) {
+  expected = Round(expected);
+  actual = Round(actual);
+  EXPECT_DOUBLE_EQ(expected, actual);
+}
+
+
+TEST(Heap, HeapGrowingFactor) {
+  CheckEqualRounded(Heap::kMaxHeapGrowingFactor,
+                    Heap::HeapGrowingFactor(34, 1));
+  CheckEqualRounded(3.553, Heap::HeapGrowingFactor(45, 1));
+  CheckEqualRounded(2.830, Heap::HeapGrowingFactor(50, 1));
+  CheckEqualRounded(1.478, Heap::HeapGrowingFactor(100, 1));
+  CheckEqualRounded(1.193, Heap::HeapGrowingFactor(200, 1));
+  CheckEqualRounded(1.121, Heap::HeapGrowingFactor(300, 1));
+  CheckEqualRounded(Heap::HeapGrowingFactor(300, 1),
+                    Heap::HeapGrowingFactor(600, 2));
+  CheckEqualRounded(Heap::kMinHeapGrowingFactor,
+                    Heap::HeapGrowingFactor(400, 1));
+}
+
+}  // namespace internal
+}  // namespace v8