8.10

1 files changed, 7 insertions, 3 deletions

diff --git a/zen/globals.h b/zen/globals.h
index a1fd2764..b6c5dd28 100755
--- a/zen/globals.h
+++ b/zen/globals.h
@@ -18,7 +18,11 @@ template <class T>
 class Global

 {

 public:

-    Global() { static_assert(std::is_trivially_destructible<Pod>::value, "this memory needs to live forever"); }

+    Global()

+    {

+        static_assert(std::is_trivially_destructible<Pod>::value, "this memory needs to live forever");

+        assert(!pod.inst && !pod.spinLock); //we depend on static zero-initialization!

+    }

     explicit Global(std::unique_ptr<T>&& newInst) { set(std::move(newInst)); }

     ~Global() { set(nullptr); }

 

@@ -50,9 +54,9 @@ private:
     //=> use trivially-destructible POD only!!!

     struct Pod

     {

-        std::shared_ptr<T>* inst = nullptr;

+        std::shared_ptr<T>* inst;   // = nullptr;

+        std::atomic<bool> spinLock; // { false }; rely entirely on static zero-initialization! => avoid potential contention with worker thread during Global<> construction!

         //serialize access; can't use std::mutex: has non-trival destructor

-        std::atomic<bool> spinLock { false };

     } pod;

 };