From c64d359b30e8960cf4a1ffa5f98730c451cfaecc Mon Sep 17 00:00:00 2001
From: Andrii Grynenko <andrii@fb.com>
Date: Wed, 1 Oct 2014 20:34:27 -0700
Subject: [PATCH] Leak folly::SingletonVault

Summary: This will ensure SingletonVault is always available. It matters for singletons, not managed by folly::Singleton. Singletons in it will actually be destroyed via static SingletonVaultDestructor.

Test Plan: unit test

Reviewed By: chip@fb.com

Subscribers: njormrod

FB internal diff: D1591270
---
 folly/experimental/Singleton.cpp | 18 ++++++++++++++++--
 folly/experimental/Singleton.h   |  2 ++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/folly/experimental/Singleton.cpp b/folly/experimental/Singleton.cpp
index 7934ab1a..ee4b2021 100644
--- a/folly/experimental/Singleton.cpp
+++ b/folly/experimental/Singleton.cpp
@@ -55,7 +55,21 @@ void SingletonVault::destroyInstances() {
 }
 
 SingletonVault* SingletonVault::singleton() {
-  static SingletonVault vault;
-  return &vault;
+  static SingletonVault* vault = new SingletonVault();
+  return vault;
 }
+
+namespace {
+
+class SingletonVaultDestructor {
+ public:
+  ~SingletonVaultDestructor() {
+    SingletonVault::singleton()->destroyInstances();
+  }
+};
+
+SingletonVaultDestructor singletonVaultDestructor;
+
+}
+
 }
diff --git a/folly/experimental/Singleton.h b/folly/experimental/Singleton.h
index c2100e0d..cbbd0319 100644
--- a/folly/experimental/Singleton.h
+++ b/folly/experimental/Singleton.h
@@ -167,6 +167,8 @@ class SingletonVault {
   enum class Type { Strict, Relaxed };
 
   explicit SingletonVault(Type type = Type::Relaxed) : type_(type) {}
+
+  // Destructor is only called by unit tests to check destroyInstances.
   ~SingletonVault();
 
   typedef std::function<void(void*)> TeardownFunc;
-- 
2.34.1