X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FManagedStatic.h;h=4fc648319ad4757ba44d6cf6153defaccdd9cefe;hb=6f2c64d70aad5328a843a6f6a6547ada69ead33b;hp=e6384c72135b6b36cde9188db14af9884945aab3;hpb=5f00b0c5b63c30c7ad6134543318551902de5c93;p=oota-llvm.git

diff --git a/include/llvm/Support/ManagedStatic.h b/include/llvm/Support/ManagedStatic.h
index e6384c72135..4fc648319ad 100644
--- a/include/llvm/Support/ManagedStatic.h
+++ b/include/llvm/Support/ManagedStatic.h
@@ -15,9 +15,16 @@
 #define LLVM_SUPPORT_MANAGED_STATIC_H
 
 #include "llvm/System/Atomic.h"
+#include "llvm/System/Threading.h"
 
 namespace llvm {
 
+/// object_creator - Helper method for ManagedStatic.
+template<class C>
+void* object_creator() {
+  return new C();
+}
+
 /// object_deleter - Helper method for ManagedStatic.
 ///
 template<class C>
@@ -28,15 +35,13 @@ void object_deleter(void *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; }
@@ -55,53 +60,32 @@ public:
 
   // Accessors.
   C &operator*() {
-    sys::cas_flag OldFlag = sys::CompareAndSwap(&InitFlag, 1, 0);
-    if (OldFlag == 0) {
-      LazyInit();
-      sys::MemoryFence();
-      InitFlag = 2;
-    } else if (OldFlag == 1)
-      while (OldFlag == 1) ;
-      
+    void* tmp = Ptr;
+    if (llvm_is_multithreaded()) sys::MemoryFence();
+    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>);
+
     return *static_cast<C*>(Ptr);
   }
   C *operator->() {
-    sys::cas_flag OldFlag = sys::CompareAndSwap(&InitFlag, 1, 0);
-    if (OldFlag == 0) {
-      LazyInit();
-      sys::MemoryFence();
-      InitFlag = 2;
-    } else if (OldFlag == 1)
-      while (OldFlag == 1) ;
-    
+    void* tmp = Ptr;
+    if (llvm_is_multithreaded()) sys::MemoryFence();
+    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>);
+
     return static_cast<C*>(Ptr);
   }
   const C &operator*() const {
-    sys::cas_flag OldFlag = sys::CompareAndSwap(&InitFlag, 1, 0);
-    if (OldFlag == 0) {
-      LazyInit();
-      sys::MemoryFence();
-      InitFlag = 2;
-    } else if (OldFlag == 1)
-      while (OldFlag == 1) ;
-    
+    void* tmp = Ptr;
+    if (llvm_is_multithreaded()) sys::MemoryFence();
+    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>);
+
     return *static_cast<C*>(Ptr);
   }
   const C *operator->() const {
-    sys::cas_flag OldFlag = sys::CompareAndSwap(&InitFlag, 1, 0);
-    if (OldFlag == 0) {
-      LazyInit();
-      sys::MemoryFence();
-      InitFlag = 2;
-    } else if (OldFlag == 1)
-      while (OldFlag == 1) ;
-    
-    return static_cast<C*>(Ptr);
-  }
+    void* tmp = Ptr;
+    if (llvm_is_multithreaded()) sys::MemoryFence();
+    if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>);
 
-public:
-  void LazyInit() const {
-    RegisterManagedStatic(new C(), object_deleter<C>);
+    return static_cast<C*>(Ptr);
   }
 };
 
@@ -111,7 +95,6 @@ public:
   void Register() { RegisterManagedStatic(0, CleanupFn); }
 };
 
-
 /// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
 void llvm_shutdown();
 
@@ -119,7 +102,10 @@ 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() { }
+  explicit llvm_shutdown_obj(bool multithreaded) {
+    if (multithreaded) llvm_start_multithreaded();
+  }
   ~llvm_shutdown_obj() { llvm_shutdown(); }
 };