src/Pure/ML-Systems/thread_dummy.ML

--- a/src/Pure/ML-Systems/thread_dummy.ML	Mon Sep 28 23:19:50 2009 +0200
+++ b/src/Pure/ML-Systems/thread_dummy.ML	Mon Sep 28 23:51:13 2009 +0200
@@ -35,6 +35,8 @@
   datatype threadAttribute = EnableBroadcastInterrupt of bool | InterruptState of interruptState
     and interruptState = InterruptDefer | InterruptSynch | InterruptAsynch | InterruptAsynchOnce;
 
+  fun unavailable () = fail ();
+
   fun fork _ = fail ();
   fun exit _ = fail ();
   fun isActive _ = fail ();