base/memory/singleton_unittest.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/at_exit.h"
   6 #include "base/memory/singleton.h"
   7 #include "base/path_service.h"
   8 #include "testing/gtest/include/gtest/gtest.h"
   9
  10 namespace {
  11
  12 COMPILE_ASSERT(DefaultSingletonTraits<int>::kRegisterAtExit == true, a);
  13
  14 typedef void (*CallbackFunc)();
  15
  16 class IntSingleton {
  17  public:
  18   static IntSingleton* GetInstance() {
  19     return Singleton<IntSingleton>::get();
  20   }
  21
  22   int value_;
  23 };
  24
  25 class Init5Singleton {
  26  public:
  27   struct Trait;
  28
  29   static Init5Singleton* GetInstance() {
  30     return Singleton<Init5Singleton, Trait>::get();
  31   }
  32
  33   int value_;
  34 };
  35
  36 struct Init5Singleton::Trait : public DefaultSingletonTraits<Init5Singleton> {
  37   static Init5Singleton* New() {
  38     Init5Singleton* instance = new Init5Singleton();
  39     instance->value_ = 5;
  40     return instance;
  41   }
  42 };
  43
  44 int* SingletonInt() {
  45   return &IntSingleton::GetInstance()->value_;
  46 }
  47
  48 int* SingletonInt5() {
  49   return &Init5Singleton::GetInstance()->value_;
  50 }
  51
  52 template <typename Type>
  53 struct CallbackTrait : public DefaultSingletonTraits<Type> {
  54   static void Delete(Type* instance) {
  55     if (instance->callback_)
  56       (instance->callback_)();
  57     DefaultSingletonTraits<Type>::Delete(instance);
  58   }
  59 };
  60
  61 class CallbackSingleton {
  62  public:
  63   CallbackSingleton() : callback_(NULL) { }
  64   CallbackFunc callback_;
  65 };
  66
  67 class CallbackSingletonWithNoLeakTrait : public CallbackSingleton {
  68  public:
  69   struct Trait : public CallbackTrait<CallbackSingletonWithNoLeakTrait> { };
  70
  71   CallbackSingletonWithNoLeakTrait() : CallbackSingleton() { }
  72
  73   static CallbackSingletonWithNoLeakTrait* GetInstance() {
  74     return Singleton<CallbackSingletonWithNoLeakTrait, Trait>::get();
  75   }
  76 };
  77
  78 class CallbackSingletonWithLeakTrait : public CallbackSingleton {
  79  public:
  80   struct Trait : public CallbackTrait<CallbackSingletonWithLeakTrait> {
  81     static const bool kRegisterAtExit = false;
  82   };
  83
  84   CallbackSingletonWithLeakTrait() : CallbackSingleton() { }
  85
  86   static CallbackSingletonWithLeakTrait* GetInstance() {
  87     return Singleton<CallbackSingletonWithLeakTrait, Trait>::get();
  88   }
  89 };
  90
  91 class CallbackSingletonWithStaticTrait : public CallbackSingleton {
  92  public:
  93   struct Trait;
  94
  95   CallbackSingletonWithStaticTrait() : CallbackSingleton() { }
  96
  97   static CallbackSingletonWithStaticTrait* GetInstance() {
  98     return Singleton<CallbackSingletonWithStaticTrait, Trait>::get();
  99   }
 100 };
 101
 102 struct CallbackSingletonWithStaticTrait::Trait
 103     : public StaticMemorySingletonTraits<CallbackSingletonWithStaticTrait> {
 104   static void Delete(CallbackSingletonWithStaticTrait* instance) {
 105     if (instance->callback_)
 106       (instance->callback_)();
 107     StaticMemorySingletonTraits<CallbackSingletonWithStaticTrait>::Delete(
 108         instance);
 109   }
 110 };
 111
 112 template <class Type>
 113 class AlignedTestSingleton {
 114  public:
 115   AlignedTestSingleton() {}
 116   ~AlignedTestSingleton() {}
 117   static AlignedTestSingleton* GetInstance() {
 118     return Singleton<AlignedTestSingleton,
 119         StaticMemorySingletonTraits<AlignedTestSingleton> >::get();
 120   }
 121
 122   Type type_;
 123 };
 124
 125
 126 void SingletonNoLeak(CallbackFunc CallOnQuit) {
 127   CallbackSingletonWithNoLeakTrait::GetInstance()->callback_ = CallOnQuit;
 128 }
 129
 130 void SingletonLeak(CallbackFunc CallOnQuit) {
 131   CallbackSingletonWithLeakTrait::GetInstance()->callback_ = CallOnQuit;
 132 }
 133
 134 CallbackFunc* GetLeakySingleton() {
 135   return &CallbackSingletonWithLeakTrait::GetInstance()->callback_;
 136 }
 137
 138 void DeleteLeakySingleton() {
 139   DefaultSingletonTraits<CallbackSingletonWithLeakTrait>::Delete(
 140       CallbackSingletonWithLeakTrait::GetInstance());
 141 }
 142
 143 void SingletonStatic(CallbackFunc CallOnQuit) {
 144   CallbackSingletonWithStaticTrait::GetInstance()->callback_ = CallOnQuit;
 145 }
 146
 147 CallbackFunc* GetStaticSingleton() {
 148   return &CallbackSingletonWithStaticTrait::GetInstance()->callback_;
 149 }
 150
 151 }  // namespace
 152
 153 class SingletonTest : public testing::Test {
 154  public:
 155   SingletonTest() {}
 156
 157   virtual void SetUp() override {
 158     non_leak_called_ = false;
 159     leaky_called_ = false;
 160     static_called_ = false;
 161   }
 162
 163  protected:
 164   void VerifiesCallbacks() {
 165     EXPECT_TRUE(non_leak_called_);
 166     EXPECT_FALSE(leaky_called_);
 167     EXPECT_TRUE(static_called_);
 168     non_leak_called_ = false;
 169     leaky_called_ = false;
 170     static_called_ = false;
 171   }
 172
 173   void VerifiesCallbacksNotCalled() {
 174     EXPECT_FALSE(non_leak_called_);
 175     EXPECT_FALSE(leaky_called_);
 176     EXPECT_FALSE(static_called_);
 177     non_leak_called_ = false;
 178     leaky_called_ = false;
 179     static_called_ = false;
 180   }
 181
 182   static void CallbackNoLeak() {
 183     non_leak_called_ = true;
 184   }
 185
 186   static void CallbackLeak() {
 187     leaky_called_ = true;
 188   }
 189
 190   static void CallbackStatic() {
 191     static_called_ = true;
 192   }
 193
 194  private:
 195   static bool non_leak_called_;
 196   static bool leaky_called_;
 197   static bool static_called_;
 198 };
 199
 200 bool SingletonTest::non_leak_called_ = false;
 201 bool SingletonTest::leaky_called_ = false;
 202 bool SingletonTest::static_called_ = false;
 203
 204 TEST_F(SingletonTest, Basic) {
 205   int* singleton_int;
 206   int* singleton_int_5;
 207   CallbackFunc* leaky_singleton;
 208   CallbackFunc* static_singleton;
 209
 210   {
 211     base::ShadowingAtExitManager sem;
 212     {
 213       singleton_int = SingletonInt();
 214     }
 215     // Ensure POD type initialization.
 216     EXPECT_EQ(*singleton_int, 0);
 217     *singleton_int = 1;
 218
 219     EXPECT_EQ(singleton_int, SingletonInt());
 220     EXPECT_EQ(*singleton_int, 1);
 221
 222     {
 223       singleton_int_5 = SingletonInt5();
 224     }
 225     // Is default initialized to 5.
 226     EXPECT_EQ(*singleton_int_5, 5);
 227
 228     SingletonNoLeak(&CallbackNoLeak);
 229     SingletonLeak(&CallbackLeak);
 230     SingletonStatic(&CallbackStatic);
 231     static_singleton = GetStaticSingleton();
 232     leaky_singleton = GetLeakySingleton();
 233     EXPECT_TRUE(leaky_singleton);
 234   }
 235
 236   // Verify that only the expected callback has been called.
 237   VerifiesCallbacks();
 238   // Delete the leaky singleton.
 239   DeleteLeakySingleton();
 240
 241   // The static singleton can't be acquired post-atexit.
 242   EXPECT_EQ(NULL, GetStaticSingleton());
 243
 244   {
 245     base::ShadowingAtExitManager sem;
 246     // Verifiy that the variables were reset.
 247     {
 248       singleton_int = SingletonInt();
 249       EXPECT_EQ(*singleton_int, 0);
 250     }
 251     {
 252       singleton_int_5 = SingletonInt5();
 253       EXPECT_EQ(*singleton_int_5, 5);
 254     }
 255     {
 256       // Resurrect the static singleton, and assert that it
 257       // still points to the same (static) memory.
 258       CallbackSingletonWithStaticTrait::Trait::Resurrect();
 259       EXPECT_EQ(GetStaticSingleton(), static_singleton);
 260     }
 261   }
 262   // The leaky singleton shouldn't leak since SingletonLeak has not been called.
 263   VerifiesCallbacksNotCalled();
 264 }
 265
 266 #define EXPECT_ALIGNED(ptr, align) \
 267     EXPECT_EQ(0u, reinterpret_cast<uintptr_t>(ptr) & (align - 1))
 268
 269 TEST_F(SingletonTest, Alignment) {
 270   using base::AlignedMemory;
 271
 272   // Create some static singletons with increasing sizes and alignment
 273   // requirements. By ordering this way, the linker will need to do some work to
 274   // ensure proper alignment of the static data.
 275   AlignedTestSingleton<int32>* align4 =
 276       AlignedTestSingleton<int32>::GetInstance();
 277   AlignedTestSingleton<AlignedMemory<32, 32> >* align32 =
 278       AlignedTestSingleton<AlignedMemory<32, 32> >::GetInstance();
 279   AlignedTestSingleton<AlignedMemory<128, 128> >* align128 =
 280       AlignedTestSingleton<AlignedMemory<128, 128> >::GetInstance();
 281   AlignedTestSingleton<AlignedMemory<4096, 4096> >* align4096 =
 282       AlignedTestSingleton<AlignedMemory<4096, 4096> >::GetInstance();
 283
 284   EXPECT_ALIGNED(align4, 4);
 285   EXPECT_ALIGNED(align32, 32);
 286   EXPECT_ALIGNED(align128, 128);
 287   EXPECT_ALIGNED(align4096, 4096);
 288 }