Implement a ScopedThreadHeapUsage class to allow profiling per-thread heap usage.

base/debug/scoped_thread_heap_usage_unittest.cc

Index: base/debug/scoped_thread_heap_usage_unittest.cc
diff --git a/base/debug/scoped_thread_heap_usage_unittest.cc b/base/debug/scoped_thread_heap_usage_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..da66a32b6306887c7f49b7e4afd93e3695b0ac69
--- /dev/null
+++ b/base/debug/scoped_thread_heap_usage_unittest.cc
@@ -0,0 +1,487 @@
+// Copyright 2016 The Chromium 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 "base/debug/scoped_thread_heap_usage.h"
+
+#include <map>
+
+#include "base/allocator/allocator_shim.h"
+#include "base/allocator/features.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace debug {
+
+namespace {
+
+class TestingScopedThreadHeapUsage : public ScopedThreadHeapUsage {
+ public:
+  using ScopedThreadHeapUsage::DisableHeapTrackingForTesting;
+  using ScopedThreadHeapUsage::GetDispatchForTesting;
+};
+
+// A fixture class that allows testing the AllocatorDispatch associated with
+// the ScopedThreadHeapUsage class in isolation against a mocked underlying
+// heap implementation.
+class ScopedThreadHeapUsageTest : public testing::Test {
+ public:
+  using AllocatorDispatch = base::allocator::AllocatorDispatch;
+
+  static const size_t kAllocationPadding;
+  enum SizeFunctionKind {
+    EXACT_SIZE_FUNCTION,
+    PADDING_SIZE_FUNCTION,
+    ZERO_SIZE_FUNCTION,
+  };
+
+  ScopedThreadHeapUsageTest() : size_function_kind_(EXACT_SIZE_FUNCTION) {
+    EXPECT_EQ(nullptr, g_self);
+    g_self = this;
+  }
+
+  ~ScopedThreadHeapUsageTest() override {
+    EXPECT_EQ(this, g_self);
+    g_self = nullptr;
+  }
+
+  void set_size_function_kind(SizeFunctionKind kind) {
+    size_function_kind_ = kind;
+  }
+
+  void SetUp() override {
+    ScopedThreadHeapUsage::Initialize();
+
+    dispatch_under_test_ =
+        TestingScopedThreadHeapUsage::GetDispatchForTesting();
+    ASSERT_EQ(nullptr, dispatch_under_test_->next);
+
+    dispatch_under_test_->next = &g_mock_dispatch;
+  }
+
+  void TearDown() override {
+    ASSERT_EQ(&g_mock_dispatch, dispatch_under_test_->next);
+
+    dispatch_under_test_->next = nullptr;
+  }
+
+  void* MockMalloc(size_t size) {
+    return dispatch_under_test_->alloc_function(dispatch_under_test_, size);
+  }
+
+  void* MockCalloc(size_t n, size_t size) {
+    return dispatch_under_test_->alloc_zero_initialized_function(
+        dispatch_under_test_, n, size);
+  }
+
+  void* MockAllocAligned(size_t alignment, size_t size) {
+    return dispatch_under_test_->alloc_aligned_function(dispatch_under_test_,
+                                                        alignment, size);
+  }
+
+  void* MockRealloc(void* address, size_t size) {
+    return dispatch_under_test_->realloc_function(dispatch_under_test_, address,
+                                                  size);
+  }
+
+  void MockFree(void* address) {
+    dispatch_under_test_->free_function(dispatch_under_test_, address);
+  }
+
+  size_t MockGetSizeEstimate(void* address) {
+    return dispatch_under_test_->get_size_estimate_function(
+        dispatch_under_test_, address);
+  }
+
+ private:
+  void RecordAlloc(void* address, size_t size) {
+    if (address != nullptr)
+      allocation_size_map_[address] = size;
+  }
+
+  void DeleteAlloc(void* address) {
+    if (address != nullptr)
+      EXPECT_EQ(1U, allocation_size_map_.erase(address));
+  }
+
+  size_t GetSizeEstimate(void* address) {
+    auto it = allocation_size_map_.find(address);
+    if (it == allocation_size_map_.end())
+      return 0;
+
+    size_t ret = it->second;
+    switch (size_function_kind_) {
+      case EXACT_SIZE_FUNCTION:
+        break;
+      case PADDING_SIZE_FUNCTION:
+        ret += kAllocationPadding;
+        break;
+      case ZERO_SIZE_FUNCTION:
+        ret = 0;
+        break;
+    }
+
+    return ret;
+  }
+
+  static void* OnAllocFn(const AllocatorDispatch* self, size_t size) {
+    EXPECT_EQ(&g_mock_dispatch, self);
+
+    void* ret = malloc(size);
+    g_self->RecordAlloc(ret, size);
+    return ret;
+  }
+
+  static void* OnAllocZeroInitializedFn(const AllocatorDispatch* self,
+                                        size_t n,
+                                        size_t size) {
+    EXPECT_EQ(&g_mock_dispatch, self);
+
+    void* ret = calloc(n, size);
+    g_self->RecordAlloc(ret, n * size);
+    return ret;
+  }
+
+  static void* OnAllocAlignedFn(const AllocatorDispatch* self,
+                                size_t alignment,
+                                size_t size) {
+    EXPECT_EQ(&g_mock_dispatch, self);
+
+    // This is a cheat as it doesn't return aligned allocations. This has the
+    // advantage of working for all platforms for this test.
+    void* ret = malloc(size);
+    g_self->RecordAlloc(ret, size);
+    return ret;
+  }
+
+  static void* OnReallocFn(const AllocatorDispatch* self,
+                           void* address,
+                           size_t size) {
+    EXPECT_EQ(&g_mock_dispatch, self);
+
+    g_self->DeleteAlloc(address);
+    void* ret = realloc(address, size);
+    g_self->RecordAlloc(ret, size);
+    return ret;
+  }
+
+  static void OnFreeFn(const AllocatorDispatch* self, void* address) {
+    EXPECT_EQ(&g_mock_dispatch, self);
+
+    g_self->DeleteAlloc(address);
+    free(address);
+  }
+
+  static size_t OnGetSizeEstimateFn(const AllocatorDispatch* self,
+                                    void* address) {
+    EXPECT_EQ(&g_mock_dispatch, self);
+
+    return g_self->GetSizeEstimate(address);
+  }
+
+  using AllocationSizeMap = std::map<void*, size_t>;
+
+  SizeFunctionKind size_function_kind_;
+  AllocationSizeMap allocation_size_map_;
+  AllocatorDispatch* dispatch_under_test_;
+
+  static base::allocator::AllocatorDispatch g_mock_dispatch;
+  static ScopedThreadHeapUsageTest* g_self;
+};
+
+const size_t ScopedThreadHeapUsageTest::kAllocationPadding = 23;
+
+ScopedThreadHeapUsageTest* ScopedThreadHeapUsageTest::g_self = nullptr;
+
+base::allocator::AllocatorDispatch ScopedThreadHeapUsageTest::g_mock_dispatch =
+    {
+        &ScopedThreadHeapUsageTest::OnAllocFn,  // alloc_function
+        &ScopedThreadHeapUsageTest::
+            OnAllocZeroInitializedFn,  // alloc_zero_initialized_function
+        &ScopedThreadHeapUsageTest::OnAllocAlignedFn,  // alloc_aligned_function
+        &ScopedThreadHeapUsageTest::OnReallocFn,       // realloc_function
+        &ScopedThreadHeapUsageTest::OnFreeFn,          // free_function
+        &ScopedThreadHeapUsageTest::
+            OnGetSizeEstimateFn,  // get_size_estimate_function
+        nullptr,                  // next
+};
+
+}  // namespace
+
+TEST_F(ScopedThreadHeapUsageTest, SimpleUsageWithExactSizeFunction) {
+  set_size_function_kind(EXACT_SIZE_FUNCTION);
+
+  ScopedThreadHeapUsage scoped_usage;
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u1 =
+      ScopedThreadHeapUsage::CurrentUsage();
+
+  EXPECT_EQ(0U, u1.alloc_ops);
+  EXPECT_EQ(0U, u1.alloc_bytes);
+  EXPECT_EQ(0U, u1.alloc_overhead_bytes);
+  EXPECT_EQ(0U, u1.free_ops);
+  EXPECT_EQ(0U, u1.free_bytes);
+  EXPECT_EQ(0U, u1.max_allocated_bytes);
+
+  const size_t kAllocSize = 1029U;
+  void* ptr = MockMalloc(kAllocSize);
+  MockFree(ptr);
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u2 =
+      ScopedThreadHeapUsage::CurrentUsage();
+
+  EXPECT_EQ(1U, u2.alloc_ops);
+  EXPECT_EQ(kAllocSize, u2.alloc_bytes);
+  EXPECT_EQ(0U, u2.alloc_overhead_bytes);
+  EXPECT_EQ(1U, u2.free_ops);
+  EXPECT_EQ(kAllocSize, u2.free_bytes);
+  EXPECT_EQ(kAllocSize, u2.max_allocated_bytes);
+}
+
+TEST_F(ScopedThreadHeapUsageTest, SimpleUsageWithPaddingSizeFunction) {
+  set_size_function_kind(PADDING_SIZE_FUNCTION);
+
+  ScopedThreadHeapUsage scoped_usage;
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u1 =
+      ScopedThreadHeapUsage::CurrentUsage();
+
+  EXPECT_EQ(0U, u1.alloc_ops);
+  EXPECT_EQ(0U, u1.alloc_bytes);
+  EXPECT_EQ(0U, u1.alloc_overhead_bytes);
+  EXPECT_EQ(0U, u1.free_ops);
+  EXPECT_EQ(0U, u1.free_bytes);
+  EXPECT_EQ(0U, u1.max_allocated_bytes);
+
+  const size_t kAllocSize = 1029U;
+  void* ptr = MockMalloc(kAllocSize);
+  MockFree(ptr);
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u2 =
+      ScopedThreadHeapUsage::CurrentUsage();
+
+  EXPECT_EQ(1U, u2.alloc_ops);
+  EXPECT_EQ(kAllocSize + kAllocationPadding, u2.alloc_bytes);
+  EXPECT_EQ(kAllocationPadding, u2.alloc_overhead_bytes);
+  EXPECT_EQ(1U, u2.free_ops);
+  EXPECT_EQ(kAllocSize + kAllocationPadding, u2.free_bytes);
+  EXPECT_EQ(kAllocSize + kAllocationPadding, u2.max_allocated_bytes);
+}
+
+TEST_F(ScopedThreadHeapUsageTest, SimpleUsageWithZeroSizeFunction) {
+  set_size_function_kind(ZERO_SIZE_FUNCTION);
+
+  ScopedThreadHeapUsage scoped_usage;
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u1 =
+      ScopedThreadHeapUsage::CurrentUsage();
+  EXPECT_EQ(0U, u1.alloc_ops);
+  EXPECT_EQ(0U, u1.alloc_bytes);
+  EXPECT_EQ(0U, u1.alloc_overhead_bytes);
+  EXPECT_EQ(0U, u1.free_ops);
+  EXPECT_EQ(0U, u1.free_bytes);
+  EXPECT_EQ(0U, u1.max_allocated_bytes);
+
+  const size_t kAllocSize = 1029U;
+  void* ptr = MockMalloc(kAllocSize);
+  MockFree(ptr);
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u2 =
+      ScopedThreadHeapUsage::CurrentUsage();
+
+  // With a get-size function that returns zero, there's no way to get the size
+  // of an allocation that's being freed, hence the shim can't tally freed bytes
+  // nor the high-watermark allocated bytes.
+  EXPECT_EQ(1U, u2.alloc_ops);
+  EXPECT_EQ(kAllocSize, u2.alloc_bytes);
+  EXPECT_EQ(0U, u2.alloc_overhead_bytes);
+  EXPECT_EQ(1U, u2.free_ops);
+  EXPECT_EQ(0U, u2.free_bytes);
+  EXPECT_EQ(0U, u2.max_allocated_bytes);
+}
+
+TEST_F(ScopedThreadHeapUsageTest, ReallocCorrectlyTallied) {
+  const size_t kAllocSize = 237U;
+
+  {
+    ScopedThreadHeapUsage scoped_usage;
+
+    // Reallocating nullptr should count as a single alloc.
+    void* ptr = MockRealloc(nullptr, kAllocSize);
+    ScopedThreadHeapUsage::ThreadAllocatorUsage usage =
+        ScopedThreadHeapUsage::CurrentUsage();
+    EXPECT_EQ(1U, usage.alloc_ops);
+    EXPECT_EQ(kAllocSize, usage.alloc_bytes);
+    EXPECT_EQ(0U, usage.alloc_overhead_bytes);
+    EXPECT_EQ(0U, usage.free_ops);
+    EXPECT_EQ(0U, usage.free_bytes);
+    EXPECT_EQ(kAllocSize, usage.max_allocated_bytes);
+
+    // Reallocating a valid pointer to a zero size should count as a single
+    // free.
+    ptr = MockRealloc(ptr, 0U);
+
+    usage = ScopedThreadHeapUsage::CurrentUsage();
+    EXPECT_EQ(1U, usage.alloc_ops);
+    EXPECT_EQ(kAllocSize, usage.alloc_bytes);
+    EXPECT_EQ(0U, usage.alloc_overhead_bytes);
+    EXPECT_EQ(1U, usage.free_ops);
+    EXPECT_EQ(kAllocSize, usage.free_bytes);
+    EXPECT_EQ(kAllocSize, usage.max_allocated_bytes);
+
+    // Realloc to zero size may or may not return a nullptr - make sure to
+    // free the zero-size alloc in the latter case.
+    if (ptr != nullptr)
+      MockFree(ptr);
+  }
+
+  {
+    ScopedThreadHeapUsage scoped_usage;
+
+    void* ptr = MockMalloc(kAllocSize);
+    ScopedThreadHeapUsage::ThreadAllocatorUsage usage =
+        ScopedThreadHeapUsage::CurrentUsage();
+    EXPECT_EQ(1U, usage.alloc_ops);
+
+    // Now try reallocating a valid pointer to a larger size, this should count
+    // as one free and one alloc.
+    const size_t kLargerAllocSize = kAllocSize + 928U;
+    ptr = MockRealloc(ptr, kLargerAllocSize);
+
+    usage = ScopedThreadHeapUsage::CurrentUsage();
+    EXPECT_EQ(2U, usage.alloc_ops);
+    EXPECT_EQ(kAllocSize + kLargerAllocSize, usage.alloc_bytes);
+    EXPECT_EQ(0U, usage.alloc_overhead_bytes);
+    EXPECT_EQ(1U, usage.free_ops);
+    EXPECT_EQ(kAllocSize, usage.free_bytes);
+    EXPECT_EQ(kLargerAllocSize, usage.max_allocated_bytes);
+
+    MockFree(ptr);
+  }
+}
+
+TEST_F(ScopedThreadHeapUsageTest, NestedMaxWorks) {
+  ScopedThreadHeapUsage outer_scoped_usage;
+
+  const size_t kOuterAllocSize = 1029U;
+  void* ptr = MockMalloc(kOuterAllocSize);
+  MockFree(ptr);
+
+  EXPECT_EQ(kOuterAllocSize,
+            ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+
+  {
+    ScopedThreadHeapUsage inner_scoped_usage;
+
+    const size_t kInnerAllocSize = 673U;
+    ptr = MockMalloc(kInnerAllocSize);
+    MockFree(ptr);
+
+    EXPECT_EQ(kInnerAllocSize,
+              ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+  }
+
+  // The greater, outer allocation size should have been restored.
+  EXPECT_EQ(kOuterAllocSize,
+            ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+
+  const size_t kLargerInnerAllocSize = kOuterAllocSize + 673U;
+  {
+    ScopedThreadHeapUsage inner_scoped_usage;
+
+    ptr = MockMalloc(kLargerInnerAllocSize);
+    MockFree(ptr);
+
+    EXPECT_EQ(kLargerInnerAllocSize,
+              ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+  }
+
+  // The greater, inner allocation size should have been preserved.
+  EXPECT_EQ(kLargerInnerAllocSize,
+            ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+
+  // Now try the case with an outstanding net alloc size when entering the
+  // inner scope.
+  void* outer_ptr = MockMalloc(kOuterAllocSize);
+  EXPECT_EQ(kLargerInnerAllocSize,
+            ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+  {
+    ScopedThreadHeapUsage inner_scoped_usage;
+
+    ptr = MockMalloc(kLargerInnerAllocSize);
+    MockFree(ptr);
+
+    EXPECT_EQ(kLargerInnerAllocSize,
+              ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+  }
+
+  // While the inner scope saw only the inner net outstanding allocation size,
+  // the outer scope saw both outstanding at the same time.
+  EXPECT_EQ(kOuterAllocSize + kLargerInnerAllocSize,
+            ScopedThreadHeapUsage::CurrentUsage().max_allocated_bytes);
+
+  MockFree(outer_ptr);
+}
+
+TEST_F(ScopedThreadHeapUsageTest, AllShimFunctionsAreProvided) {
+  const size_t kAllocSize = 100;
+  void* alloc = MockMalloc(kAllocSize);
+  size_t estimate = MockGetSizeEstimate(alloc);
+  ASSERT_TRUE(estimate == 0 || estimate >= kAllocSize);
+  MockFree(alloc);
+
+  alloc = MockCalloc(kAllocSize, 1);
+  estimate = MockGetSizeEstimate(alloc);
+  ASSERT_TRUE(estimate == 0 || estimate >= kAllocSize);
+  MockFree(alloc);
+
+  alloc = MockAllocAligned(1, kAllocSize);
+  estimate = MockGetSizeEstimate(alloc);
+  ASSERT_TRUE(estimate == 0 || estimate >= kAllocSize);
+
+  alloc = MockRealloc(alloc, kAllocSize);
+  estimate = MockGetSizeEstimate(alloc);
+  ASSERT_TRUE(estimate == 0 || estimate >= kAllocSize);
+  MockFree(alloc);
+}
+
+#if BUILDFLAG(USE_EXPERIMENTAL_ALLOCATOR_SHIM)
+TEST(ScopedThreadHeapShimTest, HooksIntoMallocWhenShimAvailable) {
+  ScopedThreadHeapUsage::Initialize();
+  ScopedThreadHeapUsage::EnableHeapTracking();
+
+  const size_t kAllocSize = 9993;
+  // This test verifies that the scoped heap data is affected by malloc &
+  // free only when the shim is available.
+  ScopedThreadHeapUsage scoped_usage;
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u1 =
+      ScopedThreadHeapUsage::CurrentUsage();
+  void* ptr = malloc(kAllocSize);
+  // Prevent the compiler from optimizing out the malloc/free pair.
+  ASSERT_NE(nullptr, ptr);
+
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u2 =
+      ScopedThreadHeapUsage::CurrentUsage();
+  free(ptr);
+  ScopedThreadHeapUsage::ThreadAllocatorUsage u3 =
+      ScopedThreadHeapUsage::CurrentUsage();
+
+  // Verify that at least one allocation operation was recorded, and that free
+  // operations are at least monotonically growing.
+  EXPECT_LE(0U, u1.alloc_ops);
+  EXPECT_LE(u1.alloc_ops + 1, u2.alloc_ops);
+  EXPECT_LE(u1.alloc_ops + 1, u3.alloc_ops);
+
+  // Verify that at least the bytes above were recorded.
+  EXPECT_LE(u1.alloc_bytes + kAllocSize, u2.alloc_bytes);
+
+  // Verify that at least the one free operation above was recorded.
+  EXPECT_LE(u2.free_ops + 1, u3.free_ops);
+
+  TestingScopedThreadHeapUsage::DisableHeapTrackingForTesting();
+}
+#endif  // BUILDFLAG(USE_EXPERIMENTAL_ALLOCATOR_SHIM)
+
+}  // namespace debug
+}  // namespace base