root/base/memory/singleton_unittest.cc

DEFINITIONS

1. GetInstance
2. GetInstance
3. SingletonInt
4. SingletonInt5
5. GetInstance
6. GetInstance
7. GetInstance
8. GetInstance
9. SingletonNoLeak
10. SingletonLeak
11. GetLeakySingleton
12. DeleteLeakySingleton
13. SingletonStatic
14. GetStaticSingleton
15. SetUp
16. VerifiesCallbacks
17. VerifiesCallbacksNotCalled
18. CallbackNoLeak
19. CallbackLeak
20. CallbackStatic
21. TEST_F
22. TEST_F

// Copyright (c) 2012 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/at_exit.h"
#include "base/memory/singleton.h"
#include "base/path_service.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

COMPILE_ASSERT(DefaultSingletonTraits<int>::kRegisterAtExit == true, a);

typedef void (*CallbackFunc)();

class IntSingleton {
 public:
  static IntSingleton* GetInstance() {
    return Singleton<IntSingleton>::get();
  }

  int value_;
};

class Init5Singleton {
 public:
  struct Trait;

  static Init5Singleton* GetInstance() {
    return Singleton<Init5Singleton, Trait>::get();
  }

  int value_;
};

struct Init5Singleton::Trait : public DefaultSingletonTraits<Init5Singleton> {
  static Init5Singleton* New() {
    Init5Singleton* instance = new Init5Singleton();
    instance->value_ = 5;
    return instance;
  }
};

int* SingletonInt() {
  return &IntSingleton::GetInstance()->value_;
}

int* SingletonInt5() {
  return &Init5Singleton::GetInstance()->value_;
}

template <typename Type>
struct CallbackTrait : public DefaultSingletonTraits<Type> {
  static void Delete(Type* instance) {
    if (instance->callback_)
      (instance->callback_)();
    DefaultSingletonTraits<Type>::Delete(instance);
  }
};

class CallbackSingleton {
 public:
  CallbackSingleton() : callback_(NULL) { }
  CallbackFunc callback_;
};

class CallbackSingletonWithNoLeakTrait : public CallbackSingleton {
 public:
  struct Trait : public CallbackTrait<CallbackSingletonWithNoLeakTrait> { };

  CallbackSingletonWithNoLeakTrait() : CallbackSingleton() { }

  static CallbackSingletonWithNoLeakTrait* GetInstance() {
    return Singleton<CallbackSingletonWithNoLeakTrait, Trait>::get();
  }
};

class CallbackSingletonWithLeakTrait : public CallbackSingleton {
 public:
  struct Trait : public CallbackTrait<CallbackSingletonWithLeakTrait> {
    static const bool kRegisterAtExit = false;
  };

  CallbackSingletonWithLeakTrait() : CallbackSingleton() { }

  static CallbackSingletonWithLeakTrait* GetInstance() {
    return Singleton<CallbackSingletonWithLeakTrait, Trait>::get();
  }
};

class CallbackSingletonWithStaticTrait : public CallbackSingleton {
 public:
  struct Trait;

  CallbackSingletonWithStaticTrait() : CallbackSingleton() { }

  static CallbackSingletonWithStaticTrait* GetInstance() {
    return Singleton<CallbackSingletonWithStaticTrait, Trait>::get();
  }
};

struct CallbackSingletonWithStaticTrait::Trait
    : public StaticMemorySingletonTraits<CallbackSingletonWithStaticTrait> {
  static void Delete(CallbackSingletonWithStaticTrait* instance) {
    if (instance->callback_)
      (instance->callback_)();
    StaticMemorySingletonTraits<CallbackSingletonWithStaticTrait>::Delete(
        instance);
  }
};

template <class Type>
class AlignedTestSingleton {
 public:
  AlignedTestSingleton() {}
  ~AlignedTestSingleton() {}
  static AlignedTestSingleton* GetInstance() {
    return Singleton<AlignedTestSingleton,
        StaticMemorySingletonTraits<AlignedTestSingleton> >::get();
  }

  Type type_;
};


void SingletonNoLeak(CallbackFunc CallOnQuit) {
  CallbackSingletonWithNoLeakTrait::GetInstance()->callback_ = CallOnQuit;
}

void SingletonLeak(CallbackFunc CallOnQuit) {
  CallbackSingletonWithLeakTrait::GetInstance()->callback_ = CallOnQuit;
}

CallbackFunc* GetLeakySingleton() {
  return &CallbackSingletonWithLeakTrait::GetInstance()->callback_;
}

void DeleteLeakySingleton() {
  DefaultSingletonTraits<CallbackSingletonWithLeakTrait>::Delete(
      CallbackSingletonWithLeakTrait::GetInstance());
}

void SingletonStatic(CallbackFunc CallOnQuit) {
  CallbackSingletonWithStaticTrait::GetInstance()->callback_ = CallOnQuit;
}

CallbackFunc* GetStaticSingleton() {
  return &CallbackSingletonWithStaticTrait::GetInstance()->callback_;
}

}  // namespace

class SingletonTest : public testing::Test {
 public:
  SingletonTest() {}

  virtual void SetUp() OVERRIDE {
    non_leak_called_ = false;
    leaky_called_ = false;
    static_called_ = false;
  }

 protected:
  void VerifiesCallbacks() {
    EXPECT_TRUE(non_leak_called_);
    EXPECT_FALSE(leaky_called_);
    EXPECT_TRUE(static_called_);
    non_leak_called_ = false;
    leaky_called_ = false;
    static_called_ = false;
  }

  void VerifiesCallbacksNotCalled() {
    EXPECT_FALSE(non_leak_called_);
    EXPECT_FALSE(leaky_called_);
    EXPECT_FALSE(static_called_);
    non_leak_called_ = false;
    leaky_called_ = false;
    static_called_ = false;
  }

  static void CallbackNoLeak() {
    non_leak_called_ = true;
  }

  static void CallbackLeak() {
    leaky_called_ = true;
  }

  static void CallbackStatic() {
    static_called_ = true;
  }

 private:
  static bool non_leak_called_;
  static bool leaky_called_;
  static bool static_called_;
};

bool SingletonTest::non_leak_called_ = false;
bool SingletonTest::leaky_called_ = false;
bool SingletonTest::static_called_ = false;

TEST_F(SingletonTest, Basic) {
  int* singleton_int;
  int* singleton_int_5;
  CallbackFunc* leaky_singleton;
  CallbackFunc* static_singleton;

  {
    base::ShadowingAtExitManager sem;
    {
      singleton_int = SingletonInt();
    }
    // Ensure POD type initialization.
    EXPECT_EQ(*singleton_int, 0);
    *singleton_int = 1;

    EXPECT_EQ(singleton_int, SingletonInt());
    EXPECT_EQ(*singleton_int, 1);

    {
      singleton_int_5 = SingletonInt5();
    }
    // Is default initialized to 5.
    EXPECT_EQ(*singleton_int_5, 5);

    SingletonNoLeak(&CallbackNoLeak);
    SingletonLeak(&CallbackLeak);
    SingletonStatic(&CallbackStatic);
    static_singleton = GetStaticSingleton();
    leaky_singleton = GetLeakySingleton();
    EXPECT_TRUE(leaky_singleton);
  }

  // Verify that only the expected callback has been called.
  VerifiesCallbacks();
  // Delete the leaky singleton.
  DeleteLeakySingleton();

  // The static singleton can't be acquired post-atexit.
  EXPECT_EQ(NULL, GetStaticSingleton());

  {
    base::ShadowingAtExitManager sem;
    // Verifiy that the variables were reset.
    {
      singleton_int = SingletonInt();
      EXPECT_EQ(*singleton_int, 0);
    }
    {
      singleton_int_5 = SingletonInt5();
      EXPECT_EQ(*singleton_int_5, 5);
    }
    {
      // Resurrect the static singleton, and assert that it
      // still points to the same (static) memory.
      CallbackSingletonWithStaticTrait::Trait::Resurrect();
      EXPECT_EQ(GetStaticSingleton(), static_singleton);
    }
  }
  // The leaky singleton shouldn't leak since SingletonLeak has not been called.
  VerifiesCallbacksNotCalled();
}

#define EXPECT_ALIGNED(ptr, align) \
    EXPECT_EQ(0u, reinterpret_cast<uintptr_t>(ptr) & (align - 1))

TEST_F(SingletonTest, Alignment) {
  using base::AlignedMemory;

  // Create some static singletons with increasing sizes and alignment
  // requirements. By ordering this way, the linker will need to do some work to
  // ensure proper alignment of the static data.
  AlignedTestSingleton<int32>* align4 =
      AlignedTestSingleton<int32>::GetInstance();
  AlignedTestSingleton<AlignedMemory<32, 32> >* align32 =
      AlignedTestSingleton<AlignedMemory<32, 32> >::GetInstance();
  AlignedTestSingleton<AlignedMemory<128, 128> >* align128 =
      AlignedTestSingleton<AlignedMemory<128, 128> >::GetInstance();
  AlignedTestSingleton<AlignedMemory<4096, 4096> >* align4096 =
      AlignedTestSingleton<AlignedMemory<4096, 4096> >::GetInstance();

  EXPECT_ALIGNED(align4, 4);
  EXPECT_ALIGNED(align32, 32);
  EXPECT_ALIGNED(align128, 128);
  EXPECT_ALIGNED(align4096, 4096);
}