fix undefined virtual_alarm

library/hacks.yap

@@ -14,7 +14,8 @@
 		      stack_dump/0,
 		      stack_dump/1,
 		      enable_interrupts/0,
-		      disable_interrupts/0
+		      disable_interrupts/0,
+		      virtual_alarm/3
               ]).
 
 stack_dump :-
@@ -35,5 +36,16 @@ run_formats([Com-Args|StackInfo], Stream) :-
 	format(Stream, Com, Args),
 	run_formats(StackInfo, user_error).
 
-
+virtual_alarm(Interval, Goal, Left) :-
+	Interval == 0, !,
+	virtual_alarm(0, 0, Left0, _),
+	on_signal(sig_alarm, _, Goal),
+	Left = Left0.
+virtual_alarm(Interval, Goal, Left) :-
+	integer(Interval), !,
+	on_signal(sig_alarm, _, Goal),
+	alarm(Interval, 0, Left, _).
+virtual_alarm(Interval.USecs, Goal, Left.LUSecs) :-
+	on_signal(sig_alarm, _, Goal),
+	virtual_alarm(Interval, USecs, Left, LUSecs).
 

library/timeout.yap

@@ -21,6 +21,11 @@
 
 :- meta_predicate time_out(:,+,-).
 
+:- use_module(library(hacks), [
+	virtual_alarm/3
+    ]).
+
+
 %
 % not the nicest program I've ever seen.
 %
@@ -30,15 +35,15 @@ time_out(Goal, Time, Result) :-
 	UT is (Time mod 1000)*1000,
 	catch( ( Result0 = success,
 	         setup_call_cleanup(
-			yap_hacks:virtual_alarm(T.UT,throw(time_out),_),
+			virtual_alarm(T.UT,throw(time_out),_),
 			Goal,
-			yap_hacks:virtual_alarm(0,_,RT)),
+			virtual_alarm(0,_,RT)),
 		 (  var(RT)
-		 -> yap_hacks:virtual_alarm(0,_,_),
+		 -> virtual_alarm(0,_,_),
 		    (
 		      true
 		    ;
-		      yap_hacks:virtual_alarm(T.UT,throw(time_out),_),
+		      virtual_alarm(T.UT,throw(time_out),_),
 		      fail
 		    )
 		 ;  true