/*
- * 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.
#include <folly/Singleton.h>
+#ifndef _WIN32
+#include <dlfcn.h>
+#endif
+
#include <atomic>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
+#include <folly/Demangle.h>
+#include <folly/Format.h>
#include <folly/ScopeGuard.h>
+#if !defined(_WIN32) && !defined(__APPLE__) && !defined(__ANDROID__)
+#define FOLLY_SINGLETON_HAVE_DLSYM 1
+#endif
+
namespace folly {
+#if FOLLY_SINGLETON_HAVE_DLSYM
namespace detail {
+static void singleton_hs_init_weak(int* argc, char** argv[])
+ __attribute__((__weakref__("hs_init")));
+} // namespace detail
+#endif
+
+SingletonVault::Type SingletonVault::defaultVaultType() {
+#if FOLLY_SINGLETON_HAVE_DLSYM
+ bool isPython = dlsym(RTLD_DEFAULT, "Py_Main");
+ bool isHaskel =
+ detail::singleton_hs_init_weak || dlsym(RTLD_DEFAULT, "hs_init");
+ bool isJVM = dlsym(RTLD_DEFAULT, "JNI_GetCreatedJavaVMs");
+ bool isD = dlsym(RTLD_DEFAULT, "_d_run_main");
+
+ return isPython || isHaskel || isJVM || isD ? Type::Relaxed : Type::Strict;
+#else
+ return Type::Relaxed;
+#endif
+}
+
+namespace detail {
+
+std::string TypeDescriptor::name() const {
+ auto ret = demangle(ti_.name());
+ if (tag_ti_ != std::type_index(typeid(DefaultTag))) {
+ ret += "/";
+ ret += demangle(tag_ti_.name());
+ }
+ return ret.toStdString();
+}
[[noreturn]] void singletonWarnDoubleRegistrationAndAbort(
const TypeDescriptor& type) {
<< type.name() << ">\n";
std::abort();
}
+
+[[noreturn]] void singletonWarnLeakyDoubleRegistrationAndAbort(
+ const TypeDescriptor& type) {
+ // Ensure the availability of std::cerr
+ std::ios_base::Init ioInit;
+ std::cerr << "Double registration of singletons of the same "
+ "underlying type; check for multiple definitions "
+ "of type folly::LeakySingleton<"
+ << type.name() << ">\n";
+ std::abort();
+}
+
+[[noreturn]] void singletonWarnLeakyInstantiatingNotRegisteredAndAbort(
+ const TypeDescriptor& type) {
+ auto ptr = SingletonVault::stackTraceGetter().load();
+ LOG(FATAL) << "Creating instance for unregistered singleton: "
+ << type.name() << "\n"
+ << "Stacktrace:"
+ << "\n" << (ptr ? (*ptr)() : "(not available)");
+}
+
+[[noreturn]] void singletonWarnRegisterMockEarlyAndAbort(
+ const TypeDescriptor& type) {
+ LOG(FATAL) << "Registering mock before singleton was registered: "
+ << type.name();
+}
+
+void singletonWarnDestroyInstanceLeak(
+ const TypeDescriptor& type,
+ const void* ptr) {
+ LOG(ERROR) << "Singleton of type " << type.name() << " has a "
+ << "living reference at destroyInstances time; beware! Raw "
+ << "pointer is " << ptr << ". It is very likely "
+ << "that some other singleton is holding a shared_ptr to it. "
+ << "This singleton will be leaked (even if a shared_ptr to it "
+ << "is eventually released)."
+ << "Make sure dependencies between these singletons are "
+ << "properly defined.";
+}
+
+[[noreturn]] void singletonWarnCreateCircularDependencyAndAbort(
+ const TypeDescriptor& type) {
+ LOG(FATAL) << "circular singleton dependency: " << type.name();
+}
+
+[[noreturn]] void singletonWarnCreateUnregisteredAndAbort(
+ const TypeDescriptor& type) {
+ auto ptr = SingletonVault::stackTraceGetter().load();
+ LOG(FATAL) << "Creating instance for unregistered singleton: "
+ << type.name() << "\n"
+ << "Stacktrace:"
+ << "\n"
+ << (ptr ? (*ptr)() : "(not available)");
+}
+
+[[noreturn]] void singletonWarnCreateBeforeRegistrationCompleteAndAbort(
+ const TypeDescriptor& type) {
+ auto stack_trace_getter = SingletonVault::stackTraceGetter().load();
+ auto stack_trace = stack_trace_getter ? stack_trace_getter() : "";
+ if (!stack_trace.empty()) {
+ stack_trace = "Stack trace:\n" + stack_trace;
+ }
+
+ LOG(FATAL) << "Singleton " << type.name() << " requested before "
+ << "registrationComplete() call.\n"
+ << "This usually means that either main() never called "
+ << "folly::init, or singleton was requested before main() "
+ << "(which is not allowed).\n"
+ << stack_trace;
+}
+
+void singletonPrintDestructionStackTrace(const TypeDescriptor& type) {
+ std::string output = "Singleton " + type.name() + " was released.\n";
+
+ auto stack_trace_getter = SingletonVault::stackTraceGetter().load();
+ auto stack_trace = stack_trace_getter ? stack_trace_getter() : "";
+ if (stack_trace.empty()) {
+ output += "Failed to get release stack trace.";
+ } else {
+ output += "Release stack trace:\n";
+ output += stack_trace;
+ }
+
+ LOG(ERROR) << output;
+}
+
+[[noreturn]] void singletonThrowNullCreator(const std::type_info& type) {
+ auto const msg = sformat(
+ "nullptr_t should be passed if you want {} to be default constructed",
+ demangle(type));
+ throw std::logic_error(msg);
}
+[[noreturn]] void singletonThrowGetInvokedAfterDestruction(
+ const TypeDescriptor& type) {
+ throw std::runtime_error(
+ "Raw pointer to a singleton requested after its destruction."
+ " Singleton type is: " +
+ type.name());
+}
+
+[[noreturn]] void SingletonVaultState::throwUnexpectedState(const char* msg) {
+ throw std::logic_error(msg);
+}
+
+} // namespace detail
+
namespace {
struct FatalHelper {
FatalHelper __attribute__ ((__init_priority__ (101))) fatalHelper;
#endif
-}
+} // namespace
SingletonVault::~SingletonVault() { destroyInstances(); }
void SingletonVault::registerSingleton(detail::SingletonHolderBase* entry) {
auto state = state_.rlock();
- stateCheck(SingletonVaultState::Running, *state);
+ state->check(detail::SingletonVaultState::Type::Running);
if (UNLIKELY(state->registrationComplete)) {
LOG(ERROR) << "Registering singleton after registrationComplete().";
void SingletonVault::addEagerInitSingleton(detail::SingletonHolderBase* entry) {
auto state = state_.rlock();
- stateCheck(SingletonVaultState::Running, *state);
+ state->check(detail::SingletonVaultState::Type::Running);
if (UNLIKELY(state->registrationComplete)) {
LOG(ERROR) << "Registering for eager-load after registrationComplete().";
std::atexit([](){ SingletonVault::singleton()->destroyInstances(); });
auto state = state_.wlock();
- stateCheck(SingletonVaultState::Running, *state);
+ state->check(detail::SingletonVaultState::Type::Running);
if (state->registrationComplete) {
return;
void SingletonVault::doEagerInit() {
{
auto state = state_.rlock();
- stateCheck(SingletonVaultState::Running, *state);
+ state->check(detail::SingletonVaultState::Type::Running);
if (UNLIKELY(!state->registrationComplete)) {
throw std::logic_error("registrationComplete() not yet called");
}
void SingletonVault::doEagerInitVia(Executor& exe, folly::Baton<>* done) {
{
auto state = state_.rlock();
- stateCheck(SingletonVaultState::Running, *state);
+ state->check(detail::SingletonVaultState::Type::Running);
if (UNLIKELY(!state->registrationComplete)) {
throw std::logic_error("registrationComplete() not yet called");
}
void SingletonVault::destroyInstances() {
auto stateW = state_.wlock();
- if (stateW->state == SingletonVaultState::Quiescing) {
+ if (stateW->state == detail::SingletonVaultState::Type::Quiescing) {
return;
}
- stateW->state = SingletonVaultState::Quiescing;
+ stateW->state = detail::SingletonVaultState::Type::Quiescing;
auto stateR = stateW.moveFromWriteToRead();
{
void SingletonVault::reenableInstances() {
auto state = state_.wlock();
- stateCheck(SingletonVaultState::Quiescing, *state);
+ state->check(detail::SingletonVaultState::Type::Quiescing);
- state->state = SingletonVaultState::Running;
+ state->state = detail::SingletonVaultState::Type::Running;
}
void SingletonVault::scheduleDestroyInstances() {
// Add a dependency on folly::ThreadLocal to make sure all its static
// singletons are initalized first.
threadlocal_detail::StaticMeta<void, void>::instance();
-
- class SingletonVaultDestructor {
- public:
- ~SingletonVaultDestructor() {
- SingletonVault::singleton()->destroyInstances();
- }
- };
-
- // Here we intialize a singleton, which calls destroyInstances in its
- // destructor. Because of singleton destruction order - it will be destroyed
- // before all the singletons, which were initialized before it and after all
- // the singletons initialized after it.
- static SingletonVaultDestructor singletonVaultDestructor;
+ std::atexit([] { SingletonVault::singleton()->destroyInstances(); });
}
-}
+} // namespace folly