1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2002-2020, University of Amsterdam 7 VU University Amsterdam 8 CWI, Amsterdam 9 All rights reserved. 10 11 Redistribution and use in source and binary forms, with or without 12 modification, are permitted provided that the following conditions 13 are met: 14 15 1. Redistributions of source code must retain the above copyright 16 notice, this list of conditions and the following disclaimer. 17 18 2. Redistributions in binary form must reproduce the above copyright 19 notice, this list of conditions and the following disclaimer in 20 the documentation and/or other materials provided with the 21 distribution. 22 23 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 26 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 27 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 28 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 29 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 31 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 33 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 POSSIBILITY OF SUCH DAMAGE. 35*/ 36 37:- module(time, 38 [ alarm/3, % +Time, :Callable, -Id 39 alarm/4, % +Time, :Callable, -Id, +Options 40 alarm_at/3, % +Time, :Callable, -Id 41 alarm_at/4, % +Time, :Callable, -Id, +Options 42 remove_alarm/1, % +Id 43 install_alarm/1, % +Id 44 install_alarm/2, % +Id, +Time 45 uninstall_alarm/1, % +Id 46 current_alarm/4, % ?At, ?:Goal, ?Id, ?Status 47 call_with_time_limit/2 % +Time, :Callable 48 ]). 49:- autoload(library(lists),[member/2]). 50 51:- set_prolog_flag(generate_debug_info, false). 52 53:- meta_predicate 54 call_with_time_limit(, ), 55 alarm(, , ), 56 alarm(, , , ), 57 alarm_at(, , , ), 58 current_alarm(, , , ). 59 60:- predicate_options(alarm/4, 4, 61 [ remove(boolean), 62 install(boolean) 63 ]).
Options is a list of Name(Value) options. Currently defined options are:
true (default false), remove the alarm-event (as
remove_alarm/1) after it has been fired.false (default true) do not install the alarm.
It must be installed separately using install_alarm/1.install(false)
option or de-activated using uninstall_alarm/1. With a given
RelTime, the alarm is scheduled at the RelTime from now.
Otherwise it is scheduled on the same (absolute) time on which
is was created.done if the alarm has
been fired, next if the event is the next to be executed and
scheduled otherwise.124:- use_foreign_library(foreign(time)). 125:- public time_debug/1. % set debugging
time_limit_exceeded is
raised. Goal is called as in once/1.
135call_with_time_limit(Time, Goal) :- 136 Time > 0, 137 !, 138 setup_call_cleanup(alarm(Time, time_limit_exceeded(Time), 139 Id, [install(false)]), 140 run_alarm_goal(Id, Goal), 141 remove_alarm_notrace(Id)). 142call_with_time_limit(_Time, _Goal) :- 143 throw(time_limit_exceeded). 144 145run_alarm_goal(AlarmID, Goal) :- 146 install_alarm(AlarmID), 147 , 148 !. 149 150time_limit_exceeded(_Time) :- 151 throw(time_limit_exceeded). 152 153current_alarm(Time, Goal, Id, Status) :- 154 current_alarms(Time, Goal, Id, Status, List), 155 member(alarm(Time, Goal, Id, Status), List). 156 157 /******************************* 158 * HANDLE MESSAGES * 159 *******************************/ 160 161:- multifile 162 prolog:message/3. 163 164prologmessage(time_limit_exceeded) --> 165 [ 'Time limit exceeded' ]. 166 167 /******************************* 168 * ALARM * 169 *******************************/ 170 171:- multifile sandbox:safe_meta_predicate/1. 172 173sandbox:safe_meta_predicate(time:call_with_time_limit/2)
Time and alarm library
*/