diff -r 591fefcf184e -r cb6421b6a18f src/Pure/ML-Systems/multithreading.ML
--- a/src/Pure/ML-Systems/multithreading.ML	Fri Mar 20 20:05:51 2009 +0100
+++ b/src/Pure/ML-Systems/multithreading.ML	Fri Mar 20 20:20:09 2009 +0100
@@ -21,6 +21,7 @@
   val enabled: unit -> bool
   val no_interrupts: Thread.threadAttribute list
   val regular_interrupts: Thread.threadAttribute list
+  val restricted_interrupts: Thread.threadAttribute list
   val with_attributes: Thread.threadAttribute list ->
     (Thread.threadAttribute list -> 'a -> 'b) -> 'a -> 'b
   val self_critical: unit -> bool
@@ -46,6 +47,9 @@
 val regular_interrupts =
   [Thread.EnableBroadcastInterrupt true, Thread.InterruptState Thread.InterruptAsynchOnce];
 
+val restricted_interrupts =
+  [Thread.EnableBroadcastInterrupt false, Thread.InterruptState Thread.InterruptAsynchOnce];
+
 fun with_attributes _ f x = f [] x;