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yap-6.3/library/timeout.yap
vsc 5affad32b6 use setitmer instead of alarm.
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1886 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
2007-05-20 23:00:38 +00:00

44 lines
1.1 KiB
Prolog

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: timeout.yap *
* Last rev: 5/12/99 *
* mods: *
* comments: Goal within timeout *
* *
*************************************************************************/
:- module(timeout, [
time_out/3
]).
:- meta_predicate time_out(:,+,-).
%
% not the nicest program I've ever seen.
%
time_out(Goal, Time, Result) :-
T is Time//1000,
UT is (Time mod 1000)*1000,
% enable alarm
alarm(T.UT,throw(time_out),_),
% launch goal and wait for signal
( catch(Goal, time_out, Result = time_out)
% make sure to disable alarm
->
alarm(0,_,_)
;
alarm(0,_,_),
fail
),
% just couldn't resist...
(Result = success -> true ; true).