1 files changed, 20 insertions, 33 deletions
diff --git a/include/llvm/Support/ManagedStatic.h b/include/llvm/Support/ManagedStatic.h
index 2e131e47177d3..ec8154b828e59 100644
--- a/include/llvm/Support/ManagedStatic.h
+++ b/include/llvm/Support/ManagedStatic.h
@@ -14,25 +14,26 @@
 #ifndef LLVM_SUPPORT_MANAGEDSTATIC_H
 #define LLVM_SUPPORT_MANAGEDSTATIC_H
 
-#include "llvm/Support/Atomic.h"
 #include "llvm/Support/Compiler.h"
-#include "llvm/Support/Threading.h"
+#include <atomic>
+#include <cstddef>
 
 namespace llvm {
 
 /// object_creator - Helper method for ManagedStatic.
 template<class C>
-void* object_creator() {
+LLVM_LIBRARY_VISIBILITY void* object_creator() {
   return new C();
 }
 
 /// object_deleter - Helper method for ManagedStatic.
 ///
-template<typename T> struct object_deleter {
-  static void call(void * Ptr) { delete (T*)Ptr; }
+template <typename T> struct LLVM_LIBRARY_VISIBILITY object_deleter {
+  static void call(void *Ptr) { delete (T *)Ptr; }
 };
-template<typename T, size_t N> struct object_deleter<T[N]> {
-  static void call(void * Ptr) { delete[] (T*)Ptr; }
+template <typename T, size_t N>
+struct LLVM_LIBRARY_VISIBILITY object_deleter<T[N]> {
+  static void call(void *Ptr) { delete[](T *)Ptr; }
 };
 
 /// ManagedStaticBase - Common base class for ManagedStatic instances.
@@ -40,7 +41,7 @@ class ManagedStaticBase {
 protected:
   // This should only be used as a static variable, which guarantees that this
   // will be zero initialized.
-  mutable void *Ptr;
+  mutable std::atomic<void *> Ptr;
   mutable void (*DeleterFn)(void*);
   mutable const ManagedStaticBase *Next;
 
@@ -60,40 +61,26 @@ public:
 template<class C>
 class ManagedStatic : public ManagedStaticBase {
 public:
-
   // Accessors.
   C &operator*() {
-    void* tmp = Ptr;
-    if (llvm_is_multithreaded()) sys::MemoryFence();
-    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
-    TsanHappensAfter(this);
+    void *Tmp = Ptr.load(std::memory_order_acquire);
+    if (!Tmp)
+      RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
 
-    return *static_cast<C*>(Ptr);
+    return *static_cast<C *>(Ptr.load(std::memory_order_relaxed));
   }
-  C *operator->() {
-    void* tmp = Ptr;
-    if (llvm_is_multithreaded()) sys::MemoryFence();
-    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
-    TsanHappensAfter(this);
 
-    return static_cast<C*>(Ptr);
-  }
+  C *operator->() { return &**this; }
+
   const C &operator*() const {
-    void* tmp = Ptr;
-    if (llvm_is_multithreaded()) sys::MemoryFence();
-    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
-    TsanHappensAfter(this);
+    void *Tmp = Ptr.load(std::memory_order_acquire);
+    if (!Tmp)
+      RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
 
-    return *static_cast<C*>(Ptr);
+    return *static_cast<C *>(Ptr.load(std::memory_order_relaxed));
   }
-  const C *operator->() const {
-    void* tmp = Ptr;
-    if (llvm_is_multithreaded()) sys::MemoryFence();
-    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
-    TsanHappensAfter(this);
 
-    return static_cast<C*>(Ptr);
-  }
+  const C *operator->() const { return &**this; }
 };
 
 /// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.