Ensure -mcpu=xscale works for arm targets, after rL252903 and rL252904

[oota-llvm.git] / include / llvm / Support / ManagedStatic.h

diff --git a/include/llvm/Support/ManagedStatic.h b/include/llvm/Support/ManagedStatic.h
index a504be31d8af61ae1764af96c1a3f350849f7900..2e131e47177d3c54ad68c0cabccc636b882c840a 100644 (file)
--- a/include/llvm/Support/ManagedStatic.h
+++ b/include/llvm/Support/ManagedStatic.h
@@ -11,35 +11,43 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_SUPPORT_MANAGED_STATIC_H
-#define LLVM_SUPPORT_MANAGED_STATIC_H
+#ifndef LLVM_SUPPORT_MANAGEDSTATIC_H
+#define LLVM_SUPPORT_MANAGEDSTATIC_H
 
-#include "llvm/System/Atomic.h"
+#include "llvm/Support/Atomic.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Threading.h"
 
 namespace llvm {
 
-/// object_deleter - Helper method for ManagedStatic.
-///
+/// object_creator - Helper method for ManagedStatic.
 template<class C>
-void object_deleter(void *Ptr) {
-  delete (C*)Ptr;
+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, size_t N> struct object_deleter<T[N]> {
+  static void call(void * Ptr) { delete[] (T*)Ptr; }
+};
+
 /// ManagedStaticBase - Common base class for ManagedStatic instances.
 class ManagedStaticBase {
 protected:
-  mutable sys::cas_flag InitFlag;
-  
   // This should only be used as a static variable, which guarantees that this
   // will be zero initialized.
   mutable void *Ptr;
   mutable void (*DeleterFn)(void*);
   mutable const ManagedStaticBase *Next;
 
-  void RegisterManagedStatic(void *ObjPtr, void (*deleter)(void*)) const;
+  void RegisterManagedStatic(void *(*creator)(), void (*deleter)(void*)) const;
 public:
   /// isConstructed - Return true if this object has not been created yet.
-  bool isConstructed() const { return Ptr != 0; }
+  bool isConstructed() const { return Ptr != nullptr; }
 
   void destroy() const;
 };
@@ -51,59 +59,50 @@ public:
 ///
 template<class C>
 class ManagedStatic : public ManagedStaticBase {
-private:
-  void checkInit() {
-    sys::cas_flag OldFlag = sys::CompareAndSwap(&InitFlag, 1, 0);
-    if (OldFlag == 0) {
-      LazyInit();
-      sys::MemoryFence();
-      InitFlag = 2;
-    } else if (OldFlag == 1) {
-      while (InitFlag == 1) ;
-      sys::MemoryFence();
-    }
-  }
 public:
 
   // Accessors.
   C &operator*() {
-    checkInit();
+    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->() {
-    checkInit();
+    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 {
-    checkInit();
+    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 {
-    checkInit();
-    return static_cast<C*>(Ptr);
-  }
+    void* tmp = Ptr;
+    if (llvm_is_multithreaded()) sys::MemoryFence();
+    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
+    TsanHappensAfter(this);
 
-public:
-  void LazyInit() const {
-    RegisterManagedStatic(new C(), object_deleter<C>);
+    return static_cast<C*>(Ptr);
   }
 };
 
-template<void (*CleanupFn)(void*)>
-class ManagedCleanup : public ManagedStaticBase {
-public:
-  void Register() { RegisterManagedStatic(0, CleanupFn); }
-};
-
-
 /// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
 void llvm_shutdown();
 
-
 /// llvm_shutdown_obj - This is a simple helper class that calls
 /// llvm_shutdown() when it is destroyed.
 struct llvm_shutdown_obj {
-  llvm_shutdown_obj() {}
+  llvm_shutdown_obj() { }
   ~llvm_shutdown_obj() { llvm_shutdown(); }
 };