From c7656e1f39228fe5f78658c1f49c980a8ac597e4 Mon Sep 17 00:00:00 2001
From: Andrii Grynenko <andrii@fb.com>
Date: Fri, 19 Aug 2016 11:55:15 -0700
Subject: [PATCH] Don't allow getting singleton after shutdown in strict mode

Summary: Make strict mode stricter, by not allowing singleton to be fetched after shutdown (even with try_get).

Reviewed By: yfeldblum

Differential Revision: D3737925

fbshipit-source-id: 8d5536c4f27e13feee722b5abeb15db6fe3d77bf
---
 folly/Singleton-inl.h | 3 +++
 folly/Singleton.h     | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/folly/Singleton-inl.h b/folly/Singleton-inl.h
index 83dbd2f6..dad943be 100644
--- a/folly/Singleton-inl.h
+++ b/folly/Singleton-inl.h
@@ -226,6 +226,9 @@ void SingletonHolder<T>::createInstance() {
 
   RWSpinLock::ReadHolder rh(&vault_.stateMutex_);
   if (vault_.state_ == SingletonVault::SingletonVaultState::Quiescing) {
+    if (vault_.type_ != SingletonVault::Type::Relaxed) {
+      LOG(FATAL) << "Requesting singleton after vault was destroyed.";
+    }
     return;
   }
 
diff --git a/folly/Singleton.h b/folly/Singleton.h
index 297cb8b9..0539e280 100644
--- a/folly/Singleton.h
+++ b/folly/Singleton.h
@@ -448,6 +448,10 @@ class SingletonVault {
     return *stackTraceGetterPtr;
   }
 
+  void setType(Type type) {
+    type_ = type;
+  }
+
  private:
   template <typename T>
   friend struct detail::SingletonHolder;
-- 
2.34.1