Index: ace/DLL_Manager.cpp
===================================================================
--- ace/DLL_Manager.cpp	(revision 81434)
+++ ace/DLL_Manager.cpp	(working copy)
@@ -344,6 +344,30 @@
   return 0;
 }
 
+void
+ACE_DLL_Handle::merge (ACE_DLL_Handle & rhs)
+{
+  if (&rhs == this)
+    {
+      return;
+    }
+  // Add rhs refcount to this->refcount the slow way
+  // This limits the types of operations that the
+  // (atomic) refcount needs to support.
+  // Because this is only executed by a corner case during
+  // which we've already loaded a dll, speed is not critical.
+  while (rhs.refcount_ != 0)
+    {
+      --rhs.refcount_;
+      ++this->refcount_;
+    }
+
+  // should we assert this->handle_ == rhs.handle_ ?
+  // how about this->dll_name+ [equals] rhs.dll_name_ ?
+  rhs.handle_ = ACE_SHLIB_INVALID_HANDLE;
+}
+
+
 ACE_SHLIB_HANDLE
 ACE_DLL_Handle::get_handle (int become_owner)
 {
@@ -509,7 +533,15 @@
           ACE_NEW_RETURN (ACE_DLL_Manager::instance_,
                           ACE_DLL_Manager (size),
                           0);
+          if (ACE::debug ())
+            {
+              ACE_DEBUG ((LM_DEBUG,
+                        ACE_LIB_TEXT ("ACE (%P|%t) DLL_Manager::instance created @%@\n"),
+                        ACE_DLL_Manager::instance_
+                      ));
+            }
         }
+
     }
 
   return ACE_DLL_Manager::instance_;
@@ -572,6 +604,11 @@
                             0);
 
             dll_handle = temp_handle;
+            if (ACE::debug ())
+              ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT("ACE (%P|%t) DLL_Manager open allocate DLL handle @%@ for %s\n"),
+                dll_handle,
+                dll_name
+                ));
           }
       }
   }
@@ -596,8 +633,37 @@
       if (temp_handle != 0)
         {
           ACE_MT (ACE_GUARD_RETURN (ACE_Thread_Mutex, ace_mon, this->lock_, 0));
-          this->handle_vector_[this->current_size_] = dll_handle;
-          ++this->current_size_;
+          // check the table again.  It may have changed while
+          // the mutex was unlocked
+          dll_handle = this->find_dll (dll_name);
+          if (dll_handle != 0)
+            {
+              // merge the new entry into the existing table entry
+              if (ACE::debug ())
+                {
+                  ACE_DEBUG ((LM_DEBUG,
+                              ACE_LIB_TEXT ("ACE_DLL_Manager::open_dll: Merge duplicate handles for %s"),
+                              dll_name));
+                }
+              dll_handle->merge (*temp_handle);
+              delete temp_handle;
+              temp_handle = 0;
+              // Todo: we executed a extra dll->open.  Do we care?
+            }
+          else
+            {
+              dll_handle = temp_handle;
+              this->handle_vector_[this->current_size_] = dll_handle;
+              ++this->current_size_;
+              if (ACE::debug ())
+                {
+                    ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT("ACE (%P|%t) DLL_Manager open save [%d] DLL handle @%@ for %s\n"),
+                      this->current_size_,
+                      dll_handle,
+                      dll_name
+                      ));
+                }
+            }
         }
     }
 
Index: ace/DLL_Manager.h
===================================================================
--- ace/DLL_Manager.h	(revision 81434)
+++ ace/DLL_Manager.h	(working copy)
@@ -102,6 +102,9 @@
    */
   ACE_SHLIB_HANDLE get_handle (int become_owner = 0);
 
+  /// Merge an existing DLL handle into this one.  Presume that they
+  /// are handles for the same DLL.
+  void merge (ACE_DLL_Handle & rhs);
 private:
 
   /// Returns a pointer to a string explaining why <symbol> or <open>