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) 2002-2015, University of Amsterdam 7 VU University Amsterdam 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in 19 the documentation and/or other materials provided with the 20 distribution. 21 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 30 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 32 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 POSSIBILITY OF SUCH DAMAGE. 34*/ 35 36:- module(time, 37 [ alarm/3, % +Time, :Callable, -Id 38 alarm/4, % +Time, :Callable, -Id, +Options 39 alarm_at/3, % +Time, :Callable, -Id 40 alarm_at/4, % +Time, :Callable, -Id, +Options 41 remove_alarm/1, % +Id 42 install_alarm/1, % +Id 43 install_alarm/2, % +Id, +Time 44 uninstall_alarm/1, % +Id 45 current_alarm/4, % ?At, ?:Goal, ?Id, ?Status 46 call_with_time_limit/2 % +Time, :Callable 47 ]). 48:- use_module(library(lists)). 49:- set_prolog_flag(generate_debug_info, false). 50 51:- meta_predicate 52 call_with_time_limit(, ), 53 alarm(, , ), 54 alarm(, , , ), 55 alarm_at(, , , ), 56 current_alarm(, , , ). 57 58:- predicate_options(alarm/4, 4, 59 [ remove(boolean), 60 install(boolean) 61 ]).
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.122:- use_foreign_library(foreign(time)). 123:- public time_debug/1. % set debugging
time_limit_exceeded is
raised. Goal is called as in once/1.
133call_with_time_limit(Time, Goal) :- 134 Time > 0, 135 !, 136 setup_call_cleanup(alarm(Time, time_limit_exceeded(Time), 137 Id, [install(false)]), 138 run_alarm_goal(Id, Goal), 139 remove_alarm_notrace(Id)). 140call_with_time_limit(_Time, _Goal) :- 141 throw(time_limit_exceeded). 142 143run_alarm_goal(AlarmID, Goal) :- 144 install_alarm(AlarmID), 145 , 146 !. 147 148time_limit_exceeded(_Time) :- 149 throw(time_limit_exceeded). 150 151current_alarm(Time, Goal, Id, Status) :- 152 current_alarms(Time, Goal, Id, Status, List), 153 member(alarm(Time, Goal, Id, Status), List). 154 155 /******************************* 156 * HANDLE MESSAGES * 157 *******************************/ 158 159:- multifile 160 prolog:message/3. 161 162prologmessage(time_limit_exceeded) --> 163 [ 'Time limit exceeded' ]. 164 165 /******************************* 166 * ALARM * 167 *******************************/ 168 169:- multifile sandbox:safe_meta_predicate/1. 170 171sandbox:safe_meta_predicate(time:call_with_time_limit/2)
Time and alarm library
*/