components/metrics: Add runtime memory leak detector

components/metrics/leak_detector/call_stack_manager_unittest.cc

+// Copyright 2015 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 "components/metrics/leak_detector/call_stack_manager.h"
+
+#include <stdint.h>
+
+#include <algorithm>
+#include <memory>
+
+#include "base/macros.h"
+#include "components/metrics/leak_detector/custom_allocator.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace metrics {
+namespace leak_detector {
+
+namespace {
+
+// Some test call stacks. The addresses are 64-bit but they should automatically
+// be truncated to 32 bits on a 32-bit machine.
+const void* kRawStack0[] = {
+  reinterpret_cast<const void*>(0x8899aabbccddeeff),
+  reinterpret_cast<const void*>(0x0000112233445566),
+  reinterpret_cast<const void*>(0x5566778899aabbcc),
+  reinterpret_cast<const void*>(0x9988776655443322),
+};
+// This is similar to kRawStack0, differing only in one address by 1. It should
+// still produce a distinct CallStack object and hash.
+const void* kRawStack1[] = {
+  kRawStack0[0],
+  kRawStack0[1],
+  reinterpret_cast<const void*>(
+      reinterpret_cast<uintptr_t>(kRawStack0[2]) + 1),
+  kRawStack0[3],
+};
+const void* kRawStack2[] = {
+  reinterpret_cast<const void*>(0x900df00dcab58888),
+  reinterpret_cast<const void*>(0x00001337cafedeed),
+  reinterpret_cast<const void*>(0x0000deafbabe1234),
+};
+const void* kRawStack3[] = {
+  reinterpret_cast<const void*>(0x0000000012345678),
+  reinterpret_cast<const void*>(0x00000000abcdef01),
+  reinterpret_cast<const void*>(0x00000000fdecab98),
+  reinterpret_cast<const void*>(0x0000deadbeef0001),
+  reinterpret_cast<const void*>(0x0000900ddeed0002),
+  reinterpret_cast<const void*>(0x0000f00dcafe0003),
+  reinterpret_cast<const void*>(0x0000f00d900d0004),
+  reinterpret_cast<const void*>(0xdeedcafebabe0005),
+};
+
+// Creates a copy of a call stack as a unique_ptr to a raw stack. The depth is
+// the same as the original stack, but it is not stored in the result.
+std::unique_ptr<const void*[]> CopyStack(const CallStack* stack) {
+  std::unique_ptr<const void*[]> stack_copy(new const void*[stack->depth]);
+  std::copy(stack->stack, stack->stack + stack->depth, stack_copy.get());
+  return std::move(stack_copy);
+}
+
+}  // namespace
+
+class CallStackManagerTest : public ::testing::Test {
+ public:
+  CallStackManagerTest() {}
+
+  void SetUp() override {
+    CustomAllocator::Initialize();
+  }
+  void TearDown() override {
+    EXPECT_TRUE(CustomAllocator::Shutdown());
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallStackManagerTest);
+};
+
+TEST_F(CallStackManagerTest, NewStacks) {
+  CallStackManager manager;
+  EXPECT_EQ(0U, manager.size());
+
+  // Request some new stacks and make sure their creation is reflected in the
+  // size of |manager|.
+  const CallStack* stack0 =
+      manager.GetCallStack(arraysize(kRawStack0), kRawStack0);
+  EXPECT_EQ(arraysize(kRawStack0), stack0->depth);
+  EXPECT_EQ(1U, manager.size());
+
+  const CallStack* stack1 =
+      manager.GetCallStack(arraysize(kRawStack1), kRawStack1);
+  EXPECT_EQ(arraysize(kRawStack1), stack1->depth);
+  EXPECT_EQ(2U, manager.size());
+
+  const CallStack* stack2 =
+      manager.GetCallStack(arraysize(kRawStack2), kRawStack2);
+  EXPECT_EQ(arraysize(kRawStack2), stack2->depth);
+  EXPECT_EQ(3U, manager.size());
+
+  const CallStack* stack3 =
+      manager.GetCallStack(arraysize(kRawStack3), kRawStack3);
+  EXPECT_EQ(arraysize(kRawStack3), stack3->depth);
+  EXPECT_EQ(4U, manager.size());
+
+  // Call stack objects should be unique.
+  EXPECT_NE(stack0, stack1);
+  EXPECT_NE(stack0, stack2);
+  EXPECT_NE(stack0, stack3);
+  EXPECT_NE(stack1, stack2);
+  EXPECT_NE(stack1, stack3);
+  EXPECT_NE(stack2, stack3);
+}
+
+TEST_F(CallStackManagerTest, Hashes) {
+  CallStackManager manager;
+
+  const CallStack* stack0 =
+      manager.GetCallStack(arraysize(kRawStack0), kRawStack0);
+  const CallStack* stack1 =
+      manager.GetCallStack(arraysize(kRawStack1), kRawStack1);
+  const CallStack* stack2 =
+      manager.GetCallStack(arraysize(kRawStack2), kRawStack2);
+  const CallStack* stack3 =
+      manager.GetCallStack(arraysize(kRawStack3), kRawStack3);
+
+  // Hash values should be nonzero.
+  EXPECT_NE(0U, stack0->hash);
+  EXPECT_NE(0U, stack1->hash);
+  EXPECT_NE(0U, stack2->hash);
+  EXPECT_NE(0U, stack3->hash);
+
+  // Hash values should be unique.
+  EXPECT_NE(stack0->hash, stack1->hash);
+  EXPECT_NE(stack0->hash, stack2->hash);
+  EXPECT_NE(stack0->hash, stack3->hash);
+  EXPECT_NE(stack1->hash, stack2->hash);
+  EXPECT_NE(stack1->hash, stack3->hash);
+  EXPECT_NE(stack2->hash, stack3->hash);
+}
+
+TEST_F(CallStackManagerTest, HashWithReducedDepth) {
+  CallStackManager manager;
+  const CallStack* stack =
+      manager.GetCallStack(arraysize(kRawStack3), kRawStack3);
+
+  // Hash function should only operate on the first |CallStack::depth| elements
+  // of CallStack::stack. To test this, reduce the depth value of one of the
+  // stacks and make sure the hash changes.
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 1, stack->stack)->hash);
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 2, stack->stack)->hash);
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 3, stack->stack)->hash);
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 4, stack->stack)->hash);
+
+  // Also try subsets of the stack that don't start from the beginning.
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 1, stack->stack + 1)->hash);
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 2, stack->stack + 2)->hash);
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 3, stack->stack + 3)->hash);
+  EXPECT_NE(stack->hash,
+            manager.GetCallStack(stack->depth - 4, stack->stack + 4)->hash);
+}
+
+TEST_F(CallStackManagerTest, DuplicateStacks) {
+  CallStackManager manager;
+  EXPECT_EQ(0U, manager.size());
+
+  // Calling manager.GetCallStack() multiple times with the same raw stack
+  // arguments will not result in creation of new call stack objects after the
+  // first call. Instead, the previously created object will be returned, and
+  // the size of |manager| will remain unchanged.
+  //
+  // Thus a call to GetCallStack() will always return the same result, given the
+  // same inputs.
+
+  // Add stack0.
+  const CallStack* stack0 =
+      manager.GetCallStack(arraysize(kRawStack0), kRawStack0);
+
+  std::unique_ptr<const void*[]> rawstack0_duplicate0 = CopyStack(stack0);
+  const CallStack* stack0_duplicate0 =
+      manager.GetCallStack(arraysize(kRawStack0), rawstack0_duplicate0.get());
+  EXPECT_EQ(1U, manager.size());
+  EXPECT_EQ(stack0, stack0_duplicate0);
+
+  // Add stack1.
+  const CallStack* stack1 =
+      manager.GetCallStack(arraysize(kRawStack1), kRawStack1);
+  EXPECT_EQ(2U, manager.size());
+
+  std::unique_ptr<const void*[]> rawstack0_duplicate1 = CopyStack(stack0);
+  const CallStack* stack0_duplicate1 =
+      manager.GetCallStack(arraysize(kRawStack0), rawstack0_duplicate1.get());
+  EXPECT_EQ(2U, manager.size());
+  EXPECT_EQ(stack0, stack0_duplicate1);
+
+  std::unique_ptr<const void*[]> rawstack1_duplicate0 = CopyStack(stack1);
+  const CallStack* stack1_duplicate0 =
+      manager.GetCallStack(arraysize(kRawStack1), rawstack1_duplicate0.get());
+  EXPECT_EQ(2U, manager.size());
+  EXPECT_EQ(stack1, stack1_duplicate0);
+
+  // Add stack2 and stack3.
+  const CallStack* stack2 =
+      manager.GetCallStack(arraysize(kRawStack2), kRawStack2);
+  const CallStack* stack3 =
+      manager.GetCallStack(arraysize(kRawStack3), kRawStack3);
+  EXPECT_EQ(4U, manager.size());
+
+  std::unique_ptr<const void*[]> rawstack1_duplicate1 = CopyStack(stack1);
+  const CallStack* stack1_duplicate1 =
+      manager.GetCallStack(arraysize(kRawStack1), rawstack1_duplicate1.get());
+  EXPECT_EQ(4U, manager.size());
+  EXPECT_EQ(stack1, stack1_duplicate1);
+
+  std::unique_ptr<const void*[]> rawstack0_duplicate2 = CopyStack(stack0);
+  const CallStack* stack0_duplicate2 =
+      manager.GetCallStack(arraysize(kRawStack0), rawstack0_duplicate2.get());
+  EXPECT_EQ(4U, manager.size());
+  EXPECT_EQ(stack0, stack0_duplicate2);
+
+  std::unique_ptr<const void*[]> rawstack3_duplicate0 = CopyStack(stack3);
+  const CallStack* stack3_duplicate0 =
+      manager.GetCallStack(arraysize(kRawStack3), rawstack3_duplicate0.get());
+  EXPECT_EQ(4U, manager.size());
+  EXPECT_EQ(stack3, stack3_duplicate0);
+
+  std::unique_ptr<const void*[]> rawstack2_duplicate0 = CopyStack(stack2);
+  const CallStack* stack2_duplicate0 =
+      manager.GetCallStack(arraysize(kRawStack2), rawstack2_duplicate0.get());
+  EXPECT_EQ(4U, manager.size());
+  EXPECT_EQ(stack2, stack2_duplicate0);
+}
+
+}  // namespace leak_detector
+}  // namespace metrics