/*
- * Copyright 2017 Facebook, Inc.
+ * Copyright 2014-present Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-
// SingletonVault - a library to manage the creation and destruction
// of interdependent singletons.
//
// should call reenableInstances.
#pragma once
-#include <folly/Baton.h>
-#include <folly/Demangle.h>
+
#include <folly/Exception.h>
#include <folly/Executor.h>
-#include <folly/Hash.h>
#include <folly/Memory.h>
-#include <folly/RWSpinLock.h>
#include <folly/Synchronized.h>
#include <folly/detail/StaticSingletonManager.h>
#include <folly/experimental/ReadMostlySharedPtr.h>
+#include <folly/hash/Hash.h>
+#include <folly/synchronization/Baton.h>
+#include <folly/synchronization/RWSpinLock.h>
#include <algorithm>
#include <atomic>
return *this;
}
- std::string name() const {
- auto ret = demangle(ti_.name());
- if (tag_ti_ != std::type_index(typeid(DefaultTag))) {
- ret += "/";
- ret += demangle(tag_ti_.name());
- }
- return ret.toStdString();
- }
+ std::string name() const;
friend class TypeDescriptorHasher;
}
};
+[[noreturn]] void singletonWarnLeakyDoubleRegistrationAndAbort(
+ const TypeDescriptor& type);
+
+[[noreturn]] void singletonWarnLeakyInstantiatingNotRegisteredAndAbort(
+ const TypeDescriptor& type);
+
+[[noreturn]] void singletonWarnRegisterMockEarlyAndAbort(
+ const TypeDescriptor& type);
+
+void singletonWarnDestroyInstanceLeak(
+ const TypeDescriptor& type,
+ const void* ptr);
+
+[[noreturn]] void singletonWarnCreateCircularDependencyAndAbort(
+ const TypeDescriptor& type);
+
+[[noreturn]] void singletonWarnCreateUnregisteredAndAbort(
+ const TypeDescriptor& type);
+
+[[noreturn]] void singletonWarnCreateBeforeRegistrationCompleteAndAbort(
+ const TypeDescriptor& type);
+
+void singletonPrintDestructionStackTrace(const TypeDescriptor& type);
+
+[[noreturn]] void singletonThrowNullCreator(const std::type_info& type);
+
+[[noreturn]] void singletonThrowGetInvokedAfterDestruction(
+ const TypeDescriptor& type);
+
+struct SingletonVaultState {
+ // The two stages of life for a vault, as mentioned in the class comment.
+ enum class Type {
+ Running,
+ Quiescing,
+ };
+
+ Type state{Type::Running};
+ bool registrationComplete{false};
+
+ // Each singleton in the vault can be in two states: dead
+ // (registered but never created), living (CreateFunc returned an instance).
+
+ void check(
+ Type expected,
+ const char* msg = "Unexpected singleton state change") const {
+ if (expected != state) {
+ throwUnexpectedState(msg);
+ }
+ }
+
+ [[noreturn]] static void throwUnexpectedState(const char* msg);
+};
+
// This interface is used by SingletonVault to interact with SingletonHolders.
// Having a non-template interface allows SingletonVault to keep a list of all
// SingletonHolders.
SingletonHolder(SingletonHolder&&) = delete;
};
-}
+} // namespace detail
class SingletonVault {
public:
*
* Sample usage:
*
- * wangle::IOThreadPoolExecutor executor(max_concurrency_level);
+ * folly::IOThreadPoolExecutor executor(max_concurrency_level);
* folly::Baton<> done;
* doEagerInitVia(executor, &done);
- * done.wait(); // or 'timed_wait', or spin with 'try_wait'
+ * done.wait(); // or 'try_wait_for', etc.
*
*/
void doEagerInitVia(Executor& exe, folly::Baton<>* done = nullptr);
template <typename T>
friend struct detail::SingletonHolder;
- // The two stages of life for a vault, as mentioned in the class comment.
- enum class SingletonVaultState {
- Running,
- Quiescing,
- };
-
- struct State {
- SingletonVaultState state{SingletonVaultState::Running};
- bool registrationComplete{false};
- };
-
- // Each singleton in the vault can be in two states: dead
- // (registered but never created), living (CreateFunc returned an instance).
-
- static void stateCheck(
- SingletonVaultState expected,
- const State& state,
- const char* msg = "Unexpected singleton state change") {
- if (expected != state.state) {
- throw std::logic_error(msg);
- }
- }
-
// This method only matters if registrationComplete() is never called.
// Otherwise destroyInstances is scheduled to be executed atexit.
//
typedef std::unordered_map<detail::TypeDescriptor,
detail::SingletonHolderBase*,
detail::TypeDescriptorHasher> SingletonMap;
- folly::Synchronized<SingletonMap> singletons_;
- folly::Synchronized<std::unordered_set<detail::SingletonHolderBase*>>
+ Synchronized<SingletonMap> singletons_;
+ Synchronized<std::unordered_set<detail::SingletonHolderBase*>>
eagerInitSingletons_;
- folly::Synchronized<std::vector<detail::TypeDescriptor>> creationOrder_;
+ Synchronized<std::vector<detail::TypeDescriptor>> creationOrder_;
// Using SharedMutexReadPriority is important here, because we want to make
// sure we don't block nested singleton creation happening concurrently with
// destroyInstances().
- folly::Synchronized<State, folly::SharedMutexReadPriority> state_;
+ Synchronized<detail::SingletonVaultState, SharedMutexReadPriority> state_;
Type type_;
};
// singletons. Create instances of this class in the global scope of
// type Singleton<T> to register your singleton for later access via
// Singleton<T>::try_get().
-template <typename T,
- typename Tag = detail::DefaultTag,
- typename VaultTag = detail::DefaultTag /* for testing */>
+template <
+ typename T,
+ typename Tag = detail::DefaultTag,
+ typename VaultTag = detail::DefaultTag /* for testing */>
class Singleton {
public:
typedef std::function<T*(void)> CreateFunc;
explicit Singleton(typename Singleton::CreateFunc c,
typename Singleton::TeardownFunc t = nullptr) {
if (c == nullptr) {
- throw std::logic_error(
- "nullptr_t should be passed if you want T to be default constructed");
+ detail::singletonThrowNullCreator(typeid(T));
}
auto vault = SingletonVault::singleton<VaultTag>();
static void make_mock(CreateFunc c,
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");
+ detail::singletonThrowNullCreator(typeid(T));
}
auto& entry = getEntry();
explicit LeakySingleton(CreateFunc createFunc) {
auto& entry = entryInstance();
if (entry.state != State::NotRegistered) {
- LOG(FATAL) << "Double registration of singletons of the same "
- << "underlying type; check for multiple definitions "
- << "of type folly::LeakySingleton<" + entry.type_.name() + ">";
+ detail::singletonWarnLeakyDoubleRegistrationAndAbort(entry.type_);
}
entry.createFunc = createFunc;
entry.state = State::Dead;
}
static void make_mock(CreateFunc createFunc) {
- auto& entry = entryInstance();
if (createFunc == nullptr) {
- throw std::logic_error(
- "nullptr_t should be passed if you want T to be default constructed");
+ detail::singletonThrowNullCreator(typeid(T));
}
+ auto& entry = entryInstance();
entry.createFunc = createFunc;
entry.state = State::Dead;
}
}
if (entry.state == State::NotRegistered) {
- auto ptr = SingletonVault::stackTraceGetter().load();
- LOG(FATAL) << "Creating instance for unregistered singleton: "
- << entry.type_.name() << "\n"
- << "Stacktrace:"
- << "\n" << (ptr ? (*ptr)() : "(not available)");
+ detail::singletonWarnLeakyInstantiatingNotRegisteredAndAbort(entry.type_);
}
entry.ptr = entry.createFunc();
entry.state = State::Living;
}
};
-}
+} // namespace folly
#include <folly/Singleton-inl.h>