Add checks to DEBUG mode that no instance of URLRequest or URLFetcher survive...

base/leak_tracker_unittest.cc

+// Copyright (c) 2009 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/leak_tracker.h"
+#include "base/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class ClassA {
+ private:
+  base::LeakTracker<ClassA> leak_tracker_;
+};
+
+class ClassB {
+ private:
+  base::LeakTracker<ClassB> leak_tracker_;
+};
+
+#ifdef NDEBUG
+
+// In RELEASE mode, leak tracking is disabled.
+TEST(LeakTrackerTest, ReleaseMode) {
+  EXPECT_EQ(-1, base::LeakTracker<ClassA>::NumLiveInstances());
+  EXPECT_EQ(-1, base::LeakTracker<ClassB>::NumLiveInstances());
+
+  // Use scoped_ptr so compiler doesn't complain about unused variables.
+  scoped_ptr<ClassA> a1(new ClassA);
+  scoped_ptr<ClassB> b1(new ClassB);
+  scoped_ptr<ClassB> b2(new ClassB);
+
+  EXPECT_EQ(-1, base::LeakTracker<ClassA>::NumLiveInstances());
+  EXPECT_EQ(-1, base::LeakTracker<ClassB>::NumLiveInstances());
+}
+
+#else
+
+// In DEBUG mode, leak tracking should work.
+TEST(LeakTrackerTest, DebugMode) {
+  {
+    ClassA a1;
+
+    EXPECT_EQ(1, base::LeakTracker<ClassA>::NumLiveInstances());
+    EXPECT_EQ(0, base::LeakTracker<ClassB>::NumLiveInstances());
+
+    ClassB b1;
+    ClassB b2;
+
+    EXPECT_EQ(1, base::LeakTracker<ClassA>::NumLiveInstances());
+    EXPECT_EQ(2, base::LeakTracker<ClassB>::NumLiveInstances());
+
+    scoped_ptr<ClassA> a2(new ClassA);
+
+    EXPECT_EQ(2, base::LeakTracker<ClassA>::NumLiveInstances());
+    EXPECT_EQ(2, base::LeakTracker<ClassB>::NumLiveInstances());
+
+    a2.reset();
+
+    EXPECT_EQ(1, base::LeakTracker<ClassA>::NumLiveInstances());
+    EXPECT_EQ(2, base::LeakTracker<ClassB>::NumLiveInstances());
+  }
+
+  EXPECT_EQ(0, base::LeakTracker<ClassA>::NumLiveInstances());
+  EXPECT_EQ(0, base::LeakTracker<ClassB>::NumLiveInstances());
+}
+
+// Try some orderings of create/remove to hit different cases in the linked-list
+// assembly.
+TEST(LeakTrackerTest, DebugMode_LinkedList) {
+  EXPECT_EQ(0, base::LeakTracker<ClassB>::NumLiveInstances());
+
+  scoped_ptr<ClassA> a1(new ClassA);
+  scoped_ptr<ClassA> a2(new ClassA);
+  scoped_ptr<ClassA> a3(new ClassA);
+  scoped_ptr<ClassA> a4(new ClassA);
+
+  EXPECT_EQ(4, base::LeakTracker<ClassA>::NumLiveInstances());
+
+  // Remove the head of the list (a1).
+  a1.reset();
+  EXPECT_EQ(3, base::LeakTracker<ClassA>::NumLiveInstances());
+
+  // Remove the tail of the list (a4).
+  a4.reset();
+  EXPECT_EQ(2, base::LeakTracker<ClassA>::NumLiveInstances());
+
+  // Append to the new tail of the list (a3).
+  scoped_ptr<ClassA> a5(new ClassA);
+  EXPECT_EQ(3, base::LeakTracker<ClassA>::NumLiveInstances());
+
+  a2.reset();
+  a3.reset();
+
+  EXPECT_EQ(1, base::LeakTracker<ClassA>::NumLiveInstances());
+
+  a5.reset();
+  EXPECT_EQ(0, base::LeakTracker<ClassA>::NumLiveInstances());
+}
+
+TEST(LeakTrackerTest, DebugMode_NoOpCheckForLeaks) {
+  // There are no live instances of ClassA, so this should do nothing.
+  base::LeakTracker<ClassA>::CheckForLeaks();
+}
+
+#endif  // NDEBUG
+
+}  // namespace