Modified double-checking pattern

1 files changed, 16 insertions, 0 deletions

diff --git a/ace/Singleton.h b/ace/Singleton.h
index f8bfa8ef8de..0e9b51cec40 100644
--- a/ace/Singleton.h
+++ b/ace/Singleton.h
@@ -73,10 +73,18 @@ protected:
 #if !defined (ACE_LACKS_STATIC_DATA_MEMBER_TEMPLATES)
   static ACE_Singleton<TYPE, ACE_LOCK> *singleton_;
   // Pointer to the Singleton (ACE_Cleanup) instance.
+
+  static int completion_flag_;
+  // A flag indicating the complete instantiation (and writing) of
+  // <singleton_>.  By checking this flag instead of <singleton_>
+  // directly, we avoid the problem of Singleton not being MP safe.
 #endif /* ACE_LACKS_STATIC_DATA_MEMBER_TEMPLATES */
 
   static ACE_Singleton<TYPE, ACE_LOCK> *&instance_i (void);
   // Get pointer to the Singleton instance.
+
+  static int &completion_flag (void);
+  // Access the singleton completion status.
 };
 
 template <class TYPE, class ACE_LOCK>
@@ -119,10 +127,18 @@ protected:
 #if !defined (ACE_LACKS_STATIC_DATA_MEMBER_TEMPLATES)
   static ACE_TSS_Singleton<TYPE, ACE_LOCK> *singleton_;
   // Pointer to the Singleton (ACE_Cleanup) instance.
+
+  static int completion_flag_;
+  // A flag indicating the complete instantiation (and writing) of
+  // <singleton_>.  By checking this flag instead of <singleton_>
+  // directly, we avoid the problem of Singleton not being MP safe.
 #endif /* ACE_LACKS_STATIC_DATA_MEMBER_TEMPLATES */
 
   static ACE_TSS_Singleton<TYPE, ACE_LOCK> *&instance_i (void);
   // Get pointer to the TSS Singleton instance.
+
+  static int &completion_flag (void);
+  // Access the singleton completion status.
 };
 
 #if defined (__ACE_INLINE__)