Don't throw on late singleton registration

Summary: Having singleton registered after registrationComplete() is called is not a hard failure. Replacing exception with ERROR, since we probably still want to avoid such situation.

Reviewed By: yfeldblum

Differential Revision: D3266376

fb-gh-sync-id: 8130d279775348c835265987c95189bd3d8106f9
fbshipit-source-id: 8130d279775348c835265987c95189bd3d8106f9

folly/Singleton.cpp

@@ -78,8 +78,7 @@ void SingletonVault::registerSingleton(detail::SingletonHolderBase* entry) {
   stateCheck(SingletonVaultState::Running);
 
   if (UNLIKELY(registrationComplete_)) {
-    throw std::logic_error(
-      "Registering singleton after registrationComplete().");
+    LOG(ERROR) << "Registering singleton after registrationComplete().";
   }
 
   RWSpinLock::ReadHolder rhMutex(&mutex_);
@@ -96,8 +95,7 @@ void SingletonVault::addEagerInitSingleton(detail::SingletonHolderBase* entry) {
   stateCheck(SingletonVaultState::Running);
 
   if (UNLIKELY(registrationComplete_)) {
-    throw std::logic_error(
-        "Registering for eager-load after registrationComplete().");
+    LOG(ERROR) << "Registering for eager-load after registrationComplete().";
   }
 
   RWSpinLock::ReadHolder rhMutex(&mutex_);