From adea360c7ae8cd3166d00b25796c7b2b00800cb4 Mon Sep 17 00:00:00 2001
From: Igor <igor88@gmail.com>
Date: Fri, 16 Sep 2016 20:18:49 +0300
Subject: [PATCH 1/5] Use statics initialization on demand fixed #331

Fixed crash CEREAL_THREAD_SAFE=1 with polymorphic class. Crash happened because StaticObject<T>::instanceMutex not initialized when StaticObject<T>::lock() called for the first time. Basically it is better to use static vars inside static functions to have predefined order of construction like it is done in StaticObject<T>::getInstance(), which calls create and forces instantiation at pre-execution time.
Also in this commit removed static T &instance; since it is possible that there were be two instances created
1) template <class T> T & StaticObject<T>::instance = StaticObject<T>::create();
2) inside StaticObject<T>::create()
---
 include/cereal/details/static_object.hpp | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/include/cereal/details/static_object.hpp b/include/cereal/details/static_object.hpp
index 6afdb75d1..b40694081 100644
--- a/include/cereal/details/static_object.hpp
+++ b/include/cereal/details/static_object.hpp
@@ -73,7 +73,7 @@ namespace cereal
         static T & create()
         {
           static T t;
-          instantiate(instance);
+          instantiate(t);
           return t;
         }
 
@@ -109,23 +109,15 @@ namespace cereal
         static LockGuard lock()
         {
           #if CEREAL_THREAD_SAFE
+          std::mutex instanceMutex;
           return LockGuard{instanceMutex};
           #else
           return LockGuard{};
           #endif
         }
 
-      private:
-        static T & instance;
-        #if CEREAL_THREAD_SAFE
-        static std::mutex instanceMutex;
-        #endif
     };
 
-    template <class T> T & StaticObject<T>::instance = StaticObject<T>::create();
-    #if CEREAL_THREAD_SAFE
-    template <class T> std::mutex StaticObject<T>::instanceMutex;
-    #endif
   } // namespace detail
 } // namespace cereal
 

From e715149f4dd18890d0abc36f5cd5df3108ac6810 Mon Sep 17 00:00:00 2001
From: Igor <igor88@gmail.com>
Date: Wed, 12 Oct 2016 10:35:38 +0300
Subject: [PATCH 2/5] Update static_object.hpp

fixed misprint
---
 include/cereal/details/static_object.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/cereal/details/static_object.hpp b/include/cereal/details/static_object.hpp
index b40694081..41ffdcc09 100644
--- a/include/cereal/details/static_object.hpp
+++ b/include/cereal/details/static_object.hpp
@@ -109,7 +109,7 @@ namespace cereal
         static LockGuard lock()
         {
           #if CEREAL_THREAD_SAFE
-          std::mutex instanceMutex;
+          static std::mutex instanceMutex;
           return LockGuard{instanceMutex};
           #else
           return LockGuard{};

From 500e7a0188c03db64c671c9cd7502b3258cb373a Mon Sep 17 00:00:00 2001
From: Igor <igor88@gmail.com>
Date: Wed, 12 Oct 2016 10:45:37 +0300
Subject: [PATCH 3/5] Update static_object.hpp

I cannot understand what is going on here with `static T & instance;`, I propose to do not change `create()`. But it would be better if someone explain what is happening here :)
---
 include/cereal/details/static_object.hpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/cereal/details/static_object.hpp b/include/cereal/details/static_object.hpp
index 41ffdcc09..2624c1083 100644
--- a/include/cereal/details/static_object.hpp
+++ b/include/cereal/details/static_object.hpp
@@ -73,7 +73,7 @@ namespace cereal
         static T & create()
         {
           static T t;
-          instantiate(t);
+          instantiate(instance);
           return t;
         }
 
@@ -115,9 +115,12 @@ namespace cereal
           return LockGuard{};
           #endif
         }
-
+      private:
+        static T & instance;
     };
 
+    template <class T> T & StaticObject<T>::instance = StaticObject<T>::create();
+
   } // namespace detail
 } // namespace cereal
 

From 74e0b1b698472b69ae2df9489984ea1d367058b7 Mon Sep 17 00:00:00 2001
From: Igor <igor88@gmail.com>
Date: Wed, 12 Oct 2016 10:47:01 +0300
Subject: [PATCH 4/5] Update static_object.hpp

removed empty extra line
---
 include/cereal/details/static_object.hpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/cereal/details/static_object.hpp b/include/cereal/details/static_object.hpp
index 2624c1083..a904d4538 100644
--- a/include/cereal/details/static_object.hpp
+++ b/include/cereal/details/static_object.hpp
@@ -120,7 +120,6 @@ namespace cereal
     };
 
     template <class T> T & StaticObject<T>::instance = StaticObject<T>::create();
-
   } // namespace detail
 } // namespace cereal
 

From 96deb7e9d30feacd7ddfe8647ffd71e9f55d625e Mon Sep 17 00:00:00 2001
From: Igor <igor88@gmail.com>
Date: Wed, 12 Oct 2016 10:47:33 +0300
Subject: [PATCH 5/5] Update static_object.hpp

---
 include/cereal/details/static_object.hpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/cereal/details/static_object.hpp b/include/cereal/details/static_object.hpp
index a904d4538..b232880c7 100644
--- a/include/cereal/details/static_object.hpp
+++ b/include/cereal/details/static_object.hpp
@@ -115,6 +115,7 @@ namespace cereal
           return LockGuard{};
           #endif
         }
+
       private:
         static T & instance;
     };