// A well-known vault; you can actually have others, but this is the
// default.
- static SingletonVault* singleton();
+ static SingletonVault* singleton() {
+ return singleton<>();
+ }
+
+ // Gets singleton vault for any Tag. Non-default tag should be used in unit
+ // tests only.
+ template <typename VaultTag = detail::DefaultTag>
+ static SingletonVault* singleton() {
+ static SingletonVault* vault = new SingletonVault();
+ return vault;
+ }
private:
// The two stages of life for a vault, as mentioned in the class comment.
// singletons. Create instances of this class in the global scope of
// type Singleton<T> to register your singleton for later access via
// Singleton<T>::get().
-template <typename T, typename Tag = detail::DefaultTag>
+template <typename T,
+ typename Tag = detail::DefaultTag,
+ typename VaultTag = detail::DefaultTag /* for testing */>
class Singleton {
public:
typedef std::function<T*(void)> CreateFunc;
// Generally your program life cycle should be fine with calling
// get() repeatedly rather than saving the reference, and then not
// call get() during process shutdown.
- static T* get(SingletonVault* vault = nullptr /* for testing */) {
+ static T* get() {
return static_cast<T*>(
- (vault ?: SingletonVault::singleton())->get_ptr(typeDescriptor()));
+ SingletonVault::singleton<VaultTag>()->get_ptr(typeDescriptor()));
}
// Same as get, but should be preffered to it in the same compilation
if (LIKELY(entry_->state == detail::SingletonEntryState::Living)) {
return reinterpret_cast<T*>(entry_->instance_ptr);
} else {
- return get(vault_);
+ return get();
}
}
// singleton, you can try to do so with a weak_ptr. Avoid this when
// possible but the inability to lock the weak pointer can be a
// signal that the vault has been destroyed.
- static std::weak_ptr<T> get_weak(
- SingletonVault* vault = nullptr /* for testing */) {
+ static std::weak_ptr<T> get_weak() {
auto weak_void_ptr =
- (vault ?: SingletonVault::singleton())->get_weak(typeDescriptor());
+ (SingletonVault::singleton<VaultTag>())->get_weak(typeDescriptor());
// This is ugly and inefficient, but there's no other way to do it, because
// there's no static_pointer_cast for weak_ptr.
}
return std::static_pointer_cast<T>(shared_void_ptr);
} else {
- return get_weak(vault_);
+ return get_weak();
}
}
T* operator->() { return ptr(); }
explicit Singleton(std::nullptr_t _ = nullptr,
- Singleton::TeardownFunc t = nullptr,
- SingletonVault* vault = nullptr) :
- Singleton ([]() { return new T; },
- std::move(t),
- vault) {
+ Singleton::TeardownFunc t = nullptr) :
+ Singleton ([]() { return new T; }, std::move(t)) {
}
explicit Singleton(Singleton::CreateFunc c,
- Singleton::TeardownFunc t = nullptr,
- SingletonVault* vault = nullptr) {
+ Singleton::TeardownFunc t = nullptr) {
if (c == nullptr) {
throw std::logic_error(
"nullptr_t should be passed if you want T to be default constructed");
}
- if (vault == nullptr) {
- vault = SingletonVault::singleton();
- }
+ auto vault = SingletonVault::singleton<VaultTag>();
- vault_ = vault;
entry_ =
&(vault->registerSingleton(typeDescriptor(), c, getTeardownFunc(t)));
}
* regular singletons.
*/
static void make_mock(std::nullptr_t c = nullptr,
- typename Singleton<T>::TeardownFunc t = nullptr,
- SingletonVault* vault = nullptr /* for testing */ ) {
- make_mock([]() { return new T; }, t, vault);
+ typename Singleton<T>::TeardownFunc t = nullptr) {
+ make_mock([]() { return new T; }, t);
}
static void make_mock(CreateFunc c,
- typename Singleton<T>::TeardownFunc t = nullptr,
- SingletonVault* vault = nullptr /* for testing */ ) {
+ typename Singleton<T>::TeardownFunc t = nullptr) {
if (c == nullptr) {
throw std::logic_error(
"nullptr_t should be passed if you want T to be default constructed");
}
- if (vault == nullptr) {
- vault = SingletonVault::singleton();
- }
+ auto vault = SingletonVault::singleton<VaultTag>();
vault->registerMockSingleton(
typeDescriptor(),
// We rely on the fact that Singleton destructor won't reset this pointer, so
// it can be "safely" used even after static Singleton object is destroyed.
detail::SingletonEntry* entry_;
- SingletonVault* vault_;
};
}
std::out_of_range);
}
+struct BasicUsageTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonBasicUsage = Singleton <T, Tag, BasicUsageTag>;
+
// Exercise some basic codepaths ensuring registration order and
// destruction order happen as expected, that instances are created
// when expected, etc etc.
TEST(Singleton, BasicUsage) {
- SingletonVault vault;
+ auto& vault = *SingletonVault::singleton<BasicUsageTag>();
EXPECT_EQ(vault.registeredSingletonCount(), 0);
- Singleton<Watchdog> watchdog_singleton(nullptr, nullptr, &vault);
+ SingletonBasicUsage<Watchdog> watchdog_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 1);
- Singleton<ChildWatchdog> child_watchdog_singleton(nullptr, nullptr, &vault);
+ SingletonBasicUsage<ChildWatchdog> child_watchdog_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 2);
vault.registrationComplete();
- Watchdog* s1 = Singleton<Watchdog>::get(&vault);
+ Watchdog* s1 = SingletonBasicUsage<Watchdog>::get();
EXPECT_NE(s1, nullptr);
- Watchdog* s2 = Singleton<Watchdog>::get(&vault);
+ Watchdog* s2 = SingletonBasicUsage<Watchdog>::get();
EXPECT_NE(s2, nullptr);
EXPECT_EQ(s1, s2);
- auto s3 = Singleton<ChildWatchdog>::get(&vault);
+ auto s3 = SingletonBasicUsage<ChildWatchdog>::get();
EXPECT_NE(s3, nullptr);
EXPECT_NE(s2, s3);
EXPECT_EQ(vault.livingSingletonCount(), 0);
}
+struct DirectUsageTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonDirectUsage = Singleton <T, Tag, DirectUsageTag>;
+
TEST(Singleton, DirectUsage) {
- SingletonVault vault;
+ auto& vault = *SingletonVault::singleton<DirectUsageTag>();
EXPECT_EQ(vault.registeredSingletonCount(), 0);
// Verify we can get to the underlying singletons via directly using
// the singleton definition.
- Singleton<Watchdog> watchdog(nullptr, nullptr, &vault);
+ SingletonDirectUsage<Watchdog> watchdog;
struct TestTag {};
- Singleton<Watchdog, TestTag> named_watchdog(nullptr, nullptr, &vault);
+ SingletonDirectUsage<Watchdog, TestTag> named_watchdog;
EXPECT_EQ(vault.registeredSingletonCount(), 2);
vault.registrationComplete();
EXPECT_NE(watchdog.ptr(), nullptr);
- EXPECT_EQ(watchdog.ptr(), Singleton<Watchdog>::get(&vault));
+ EXPECT_EQ(watchdog.ptr(), SingletonDirectUsage<Watchdog>::get());
EXPECT_NE(watchdog.ptr(), named_watchdog.ptr());
EXPECT_EQ(watchdog->livingWatchdogCount(), 2);
EXPECT_EQ((*watchdog).livingWatchdogCount(), 2);
+
+ vault.destroyInstances();
}
+struct NamedUsageTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonNamedUsage = Singleton <T, Tag, NamedUsageTag>;
+
TEST(Singleton, NamedUsage) {
- SingletonVault vault;
+ auto& vault = *SingletonVault::singleton<NamedUsageTag>();
EXPECT_EQ(vault.registeredSingletonCount(), 0);
struct Watchdog1 {};
struct Watchdog2 {};
typedef detail::DefaultTag Watchdog3;
- Singleton<Watchdog, Watchdog1> watchdog1_singleton(nullptr, nullptr, &vault);
+ SingletonNamedUsage<Watchdog, Watchdog1> watchdog1_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 1);
- Singleton<Watchdog, Watchdog2> watchdog2_singleton(nullptr, nullptr, &vault);
+ SingletonNamedUsage<Watchdog, Watchdog2> watchdog2_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 2);
- Singleton<Watchdog, Watchdog3> watchdog3_singleton(nullptr, nullptr, &vault);
+ SingletonNamedUsage<Watchdog, Watchdog3> watchdog3_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 3);
vault.registrationComplete();
// Verify our three singletons are distinct and non-nullptr.
- Watchdog* s1 = Singleton<Watchdog, Watchdog1>::get(&vault);
+ Watchdog* s1 = SingletonNamedUsage<Watchdog, Watchdog1>::get();
EXPECT_EQ(s1, watchdog1_singleton.ptr());
- Watchdog* s2 = Singleton<Watchdog, Watchdog2>::get(&vault);
+ Watchdog* s2 = SingletonNamedUsage<Watchdog, Watchdog2>::get();
EXPECT_EQ(s2, watchdog2_singleton.ptr());
EXPECT_NE(s1, s2);
- Watchdog* s3 = Singleton<Watchdog, Watchdog3>::get(&vault);
+ Watchdog* s3 = SingletonNamedUsage<Watchdog, Watchdog3>::get();
EXPECT_EQ(s3, watchdog3_singleton.ptr());
EXPECT_NE(s3, s1);
EXPECT_NE(s3, s2);
// Verify the "default" singleton is the same as the DefaultTag-tagged
// singleton.
- Watchdog* s4 = Singleton<Watchdog>::get(&vault);
+ Watchdog* s4 = SingletonNamedUsage<Watchdog>::get();
EXPECT_EQ(s4, watchdog3_singleton.ptr());
+
+ vault.destroyInstances();
}
+struct NaughtyUsageTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonNaughtyUsage = Singleton <T, Tag, NaughtyUsageTag>;
+struct NaughtyUsageTag2 {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonNaughtyUsage2 = Singleton <T, Tag, NaughtyUsageTag2>;
+
// Some pathological cases such as getting unregistered singletons,
// double registration, etc.
TEST(Singleton, NaughtyUsage) {
- SingletonVault vault(SingletonVault::Type::Strict);
+ auto& vault = *SingletonVault::singleton<NaughtyUsageTag>();
+
vault.registrationComplete();
// Unregistered.
EXPECT_THROW(Singleton<Watchdog>::get(), std::out_of_range);
- EXPECT_THROW(Singleton<Watchdog>::get(&vault), std::out_of_range);
-
- // Registring singletons after registrationComplete called.
- EXPECT_THROW([&vault]() {
- Singleton<Watchdog> watchdog_singleton(
- nullptr, nullptr, &vault);
- }(),
- std::logic_error);
-
- SingletonVault vault_2(SingletonVault::Type::Strict);
- EXPECT_THROW(Singleton<Watchdog>::get(&vault_2), std::logic_error);
- Singleton<Watchdog> watchdog_singleton(nullptr, nullptr, &vault_2);
+ EXPECT_THROW(SingletonNaughtyUsage<Watchdog>::get(), std::out_of_range);
+
+ vault.destroyInstances();
+
+ auto& vault2 = *SingletonVault::singleton<NaughtyUsageTag2>();
+
+ EXPECT_THROW(SingletonNaughtyUsage2<Watchdog>::get(), std::logic_error);
+ SingletonNaughtyUsage2<Watchdog> watchdog_singleton;
// double registration
- EXPECT_THROW([&vault_2]() {
- Singleton<Watchdog> watchdog_singleton(
- nullptr, nullptr, &vault_2);
- }(),
- std::logic_error);
- vault_2.destroyInstances();
+ EXPECT_THROW([]() {
+ SingletonNaughtyUsage2<Watchdog> watchdog_singleton;
+ }(),
+ std::logic_error);
+ vault2.destroyInstances();
// double registration after destroy
- EXPECT_THROW([&vault_2]() {
- Singleton<Watchdog> watchdog_singleton(
- nullptr, nullptr, &vault_2);
- }(),
- std::logic_error);
+ EXPECT_THROW([]() {
+ SingletonNaughtyUsage2<Watchdog> watchdog_singleton;
+ }(),
+ std::logic_error);
}
+struct SharedPtrUsageTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonSharedPtrUsage = Singleton <T, Tag, SharedPtrUsageTag>;
+
TEST(Singleton, SharedPtrUsage) {
- SingletonVault vault;
+ auto& vault = *SingletonVault::singleton<SharedPtrUsageTag>();
EXPECT_EQ(vault.registeredSingletonCount(), 0);
- Singleton<Watchdog> watchdog_singleton(nullptr, nullptr, &vault);
+ SingletonSharedPtrUsage<Watchdog> watchdog_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 1);
- Singleton<ChildWatchdog> child_watchdog_singleton(nullptr, nullptr, &vault);
+ SingletonSharedPtrUsage<ChildWatchdog> child_watchdog_singleton;
EXPECT_EQ(vault.registeredSingletonCount(), 2);
struct ATag {};
- Singleton<Watchdog, ATag> named_watchdog_singleton(nullptr, nullptr, &vault);
+ SingletonSharedPtrUsage<Watchdog, ATag> named_watchdog_singleton;
vault.registrationComplete();
- Watchdog* s1 = Singleton<Watchdog>::get(&vault);
+ Watchdog* s1 = SingletonSharedPtrUsage<Watchdog>::get();
EXPECT_NE(s1, nullptr);
- Watchdog* s2 = Singleton<Watchdog>::get(&vault);
+ Watchdog* s2 = SingletonSharedPtrUsage<Watchdog>::get();
EXPECT_NE(s2, nullptr);
EXPECT_EQ(s1, s2);
- auto weak_s1 = Singleton<Watchdog>::get_weak(&vault);
+ auto weak_s1 = SingletonSharedPtrUsage<Watchdog>::get_weak();
auto shared_s1 = weak_s1.lock();
EXPECT_EQ(shared_s1.get(), s1);
EXPECT_EQ(shared_s1.use_count(), 2);
{
- auto named_weak_s1 = Singleton<Watchdog, ATag>::get_weak(&vault);
+ auto named_weak_s1 =
+ SingletonSharedPtrUsage<Watchdog, ATag>::get_weak();
auto locked = named_weak_s1.lock();
EXPECT_NE(locked.get(), shared_s1.get());
}
locked_s1 = weak_s1.lock();
EXPECT_TRUE(weak_s1.expired());
- auto empty_s1 = Singleton<Watchdog>::get_weak(&vault);
+ auto empty_s1 = SingletonSharedPtrUsage<Watchdog>::get_weak();
EXPECT_FALSE(empty_s1.lock());
vault.reenableInstances();
// Singleton should be re-created only after reenableInstances() was called.
- Watchdog* new_s1 = Singleton<Watchdog>::get(&vault);
+ Watchdog* new_s1 = SingletonSharedPtrUsage<Watchdog>::get();
EXPECT_NE(new_s1->serial_number, old_serial);
- auto new_s1_weak = Singleton<Watchdog>::get_weak(&vault);
+ auto new_s1_weak = SingletonSharedPtrUsage<Watchdog>::get_weak();
auto new_s1_shared = new_s1_weak.lock();
std::thread t([new_s1_shared]() mutable {
std::this_thread::sleep_for(std::chrono::seconds{2});
// Some classes to test singleton dependencies. NeedySingleton has a
// dependency on NeededSingleton, which happens during its
// construction.
-SingletonVault needy_vault;
+struct NeedyTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonNeedy = Singleton <T, Tag, NeedyTag>;
struct NeededSingleton {};
struct NeedySingleton {
NeedySingleton() {
- auto unused = Singleton<NeededSingleton>::get(&needy_vault);
+ auto unused = SingletonNeedy<NeededSingleton>::get();
EXPECT_NE(unused, nullptr);
}
};
// Ensure circular dependencies fail -- a singleton that needs itself, whoops.
-SingletonVault self_needy_vault;
+struct SelfNeedyTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonSelfNeedy = Singleton <T, Tag, SelfNeedyTag>;
+
struct SelfNeedySingleton {
SelfNeedySingleton() {
- auto unused = Singleton<SelfNeedySingleton>::get(&self_needy_vault);
+ auto unused = SingletonSelfNeedy<SelfNeedySingleton>::get();
EXPECT_NE(unused, nullptr);
}
};
TEST(Singleton, SingletonDependencies) {
- Singleton<NeededSingleton> needed_singleton(nullptr, nullptr, &needy_vault);
- Singleton<NeedySingleton> needy_singleton(nullptr, nullptr, &needy_vault);
+ SingletonNeedy<NeededSingleton> needed_singleton;
+ SingletonNeedy<NeedySingleton> needy_singleton;
+ auto& needy_vault = *SingletonVault::singleton<NeedyTag>();
+
needy_vault.registrationComplete();
EXPECT_EQ(needy_vault.registeredSingletonCount(), 2);
EXPECT_EQ(needy_vault.livingSingletonCount(), 0);
- auto needy = Singleton<NeedySingleton>::get(&needy_vault);
+ auto needy = SingletonNeedy<NeedySingleton>::get();
EXPECT_EQ(needy_vault.livingSingletonCount(), 2);
- Singleton<SelfNeedySingleton> self_needy_singleton(
- nullptr, nullptr, &self_needy_vault);
+ SingletonSelfNeedy<SelfNeedySingleton> self_needy_singleton;
+ auto& self_needy_vault = *SingletonVault::singleton<SelfNeedyTag>();
+
self_needy_vault.registrationComplete();
EXPECT_THROW([]() {
- Singleton<SelfNeedySingleton>::get(&self_needy_vault);
- }(),
- std::out_of_range);
+ SingletonSelfNeedy<SelfNeedySingleton>::get();
+ }(),
+ std::out_of_range);
}
// A test to ensure multiple threads contending on singleton creation
Slowpoke() { std::this_thread::sleep_for(std::chrono::milliseconds(10)); }
};
+struct ConcurrencyTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonConcurrency = Singleton <T, Tag, ConcurrencyTag>;
+
TEST(Singleton, SingletonConcurrency) {
- SingletonVault vault;
- Singleton<Slowpoke> slowpoke_singleton(nullptr, nullptr, &vault);
+ auto& vault = *SingletonVault::singleton<ConcurrencyTag>();
+ SingletonConcurrency<Slowpoke> slowpoke_singleton;
vault.registrationComplete();
std::mutex gatekeeper;
gatekeeper.lock();
- auto func = [&vault, &gatekeeper]() {
+ auto func = [&gatekeeper]() {
gatekeeper.lock();
gatekeeper.unlock();
- auto unused = Singleton<Slowpoke>::get(&vault);
+ auto unused = SingletonConcurrency<Slowpoke>::get();
};
EXPECT_EQ(vault.livingSingletonCount(), 0);
EXPECT_EQ(vault.livingSingletonCount(), 1);
}
+struct ConcurrencyStressTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonConcurrencyStress = Singleton <T, Tag, ConcurrencyStressTag>;
+
TEST(Singleton, SingletonConcurrencyStress) {
- SingletonVault vault;
- Singleton<Slowpoke> slowpoke_singleton(nullptr, nullptr, &vault);
+ auto& vault = *SingletonVault::singleton<ConcurrencyStressTag>();
+ SingletonConcurrencyStress<Slowpoke> slowpoke_singleton;
std::vector<std::thread> ts;
for (size_t i = 0; i < 100; ++i) {
ts.emplace_back([&]() {
- slowpoke_singleton.get_weak(&vault).lock();
+ slowpoke_singleton.get_weak().lock();
});
}
return &normal_singleton_value;
}
+struct MockTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonMock = Singleton <T, Tag, MockTag>;
+
// Verify that existing Singleton's can be overridden
// using the make_mock functionality.
-TEST(Singleton, make_mock) {
- SingletonVault vault(SingletonVault::Type::Strict);
- Singleton<Watchdog> watchdog_singleton(nullptr, nullptr, &vault);
+TEST(Singleton, MockTest) {
+ auto& vault = *SingletonVault::singleton<MockTag>();
+
+ SingletonMock<Watchdog> watchdog_singleton;
vault.registrationComplete();
// Registring singletons after registrationComplete called works
// with make_mock (but not with Singleton ctor).
EXPECT_EQ(vault.registeredSingletonCount(), 1);
- int serial_count_first = Singleton<Watchdog>::get(&vault)->serial_number;
+ int serial_count_first = SingletonMock<Watchdog>::get()->serial_number;
// Override existing mock using make_mock.
- Singleton<Watchdog>::make_mock(nullptr, nullptr, &vault);
+ SingletonMock<Watchdog>::make_mock();
EXPECT_EQ(vault.registeredSingletonCount(), 1);
- int serial_count_mock = Singleton<Watchdog>::get(&vault)->serial_number;
+ int serial_count_mock = SingletonMock<Watchdog>::get()->serial_number;
// If serial_count value is the same, then singleton was not replaced.
EXPECT_NE(serial_count_first, serial_count_mock);
}
}
-BENCHMARK_RELATIVE(FollySingletonSlow, n) {
- SingletonVault benchmark_vault;
- Singleton<BenchmarkSingleton> benchmark_singleton(
- nullptr, nullptr, &benchmark_vault);
- benchmark_vault.registrationComplete();
+struct BenchmarkTag {};
+template <typename T, typename Tag = detail::DefaultTag>
+using SingletonBenchmark = Singleton <T, Tag, BenchmarkTag>;
+
+SingletonBenchmark<BenchmarkSingleton> benchmark_singleton;
+BENCHMARK_RELATIVE(FollySingletonSlow, n) {
for (size_t i = 0; i < n; ++i) {
- doNotOptimizeAway(Singleton<BenchmarkSingleton>::get(&benchmark_vault));
+ doNotOptimizeAway(SingletonBenchmark<BenchmarkSingleton>::get());
}
}
BENCHMARK_RELATIVE(FollySingletonFast, n) {
- SingletonVault benchmark_vault;
- Singleton<BenchmarkSingleton> benchmark_singleton(
- nullptr, nullptr, &benchmark_vault);
- benchmark_vault.registrationComplete();
-
for (size_t i = 0; i < n; ++i) {
doNotOptimizeAway(benchmark_singleton.get_fast());
}
}
BENCHMARK_RELATIVE(FollySingletonFastWeak, n) {
- SingletonVault benchmark_vault;
- Singleton<BenchmarkSingleton> benchmark_singleton(
- nullptr, nullptr, &benchmark_vault);
- benchmark_vault.registrationComplete();
-
for (size_t i = 0; i < n; ++i) {
benchmark_singleton.get_weak_fast();
}
projects / folly.git / commitdiff