137 lines
4.4 KiB
Prolog
137 lines
4.4 KiB
Prolog
/* $Id$
|
|
|
|
Part of SWI-Prolog
|
|
|
|
Author: Jan Wielemaker
|
|
E-mail: J.Wielemaker@cs.vu.nl
|
|
WWW: http://www.swi-prolog.org
|
|
Copyright (C): 1985-2009, University of Amsterdam
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License
|
|
as published by the Free Software Foundation; either version 2
|
|
of the License, or (at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with this library; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
As a special exception, if you link this library with other files,
|
|
compiled with a Free Software compiler, to produce an executable, this
|
|
library does not by itself cause the resulting executable to be covered
|
|
by the GNU General Public License. This exception does not however
|
|
invalidate any other reasons why the executable file might be covered by
|
|
the GNU General Public License.
|
|
*/
|
|
|
|
:- module(time,
|
|
[ alarm/3, % +Time, :Callable, -Id
|
|
alarm/4, % +Time, :Callable, -Id, +Options
|
|
alarm_at/4, % +Time, :Callable, -Id, +Options
|
|
remove_alarm/1, % +Id
|
|
install_alarm/1, % +Id
|
|
install_alarm/2, % +Id, +Time
|
|
uninstall_alarm/1, % +Id
|
|
current_alarm/4, % ?At, ?:Goal, ?Id, ?Status
|
|
call_with_time_limit/2 % +Time, :Callable
|
|
]).
|
|
:- use_module(library(lists)).
|
|
:- set_prolog_flag(generate_debug_info, false).
|
|
|
|
:- meta_predicate
|
|
call_with_time_limit(+, 0),
|
|
alarm(+, 0, -),
|
|
alarm(+, 0, -, +),
|
|
alarm_at(+, 0, -, +).
|
|
|
|
%% alarm(+Time, :Callable, -Id) is det.
|
|
%% alarm(+Time, :Callable, -Id, +Options) is det.
|
|
%
|
|
% Set up an alarm to be signaled Time seconds from now. If the
|
|
% alarm expires, Callable is called asynchronously. Callable can
|
|
% be used to raise an exception using throw/1 to abort some
|
|
% execution.
|
|
%
|
|
% Options is a list of Name(Value) options. Currently defined
|
|
% options are:
|
|
%
|
|
% * remove(Bool)
|
|
% If =true= (default =false=), remove the alarm-event (as
|
|
% remove_alarm/1) after it has been fired.
|
|
% * install(Bool)
|
|
% If =false= (default =true=) do not install the alarm.
|
|
% It must be installed separately using install_alarm/1.
|
|
|
|
%% alarm_at(+Time, :Callable, -Id, +Options) is det
|
|
%
|
|
% As alarm/4, but schedule the alarm at an absolute point in time.
|
|
%
|
|
% @see date_time_stamp/2.
|
|
|
|
%% install_alarm(+Id) is det.
|
|
%
|
|
% Install an alarm allocated using alarm/4 with the install(false)
|
|
% option.
|
|
%
|
|
% @deprecated With the introduction of setup_call_cleanup/3,
|
|
% this predicate is probably no longer needed.
|
|
|
|
%% remove_alarm(+Id) is det.
|
|
%
|
|
% Remove an alarm. If it has not yet been fired, it never will.
|
|
|
|
%% current_alarm(?Time, :Goal, ?Id, ?Status) is nondet.
|
|
%
|
|
% Enumerate the alarms in the schedule. Time is the absolute time
|
|
% the event is scheduled for (see also get_time/1). Goal is the
|
|
% goal to execute, Id is the identifier and Status is the
|
|
% scheduling status. It takes the value =done= if the alarm has
|
|
% been fired, =next= if the event is the next to be executed and
|
|
% =scheduled= otherwise.
|
|
|
|
:- use_foreign_library(foreign(time)).
|
|
|
|
%% call_with_time_limit(+Time, :Goal) is semidet.
|
|
%
|
|
% Call Goal, while watching out for a (wall-time) limit. If this
|
|
% limit is exceeded, the exception =time_limit_exceeded= is
|
|
% raised. Goal is called as in once/1.
|
|
%
|
|
% @throws =time_limit_exceeded=
|
|
|
|
call_with_time_limit(Time, Goal) :-
|
|
Time > 0, !,
|
|
setup_call_cleanup(alarm(Time, time_limit_exceeded(Time),
|
|
Id, [install(false)]),
|
|
run_alarm_goal(Id, Goal),
|
|
remove_alarm_notrace(Id)).
|
|
call_with_time_limit(_Time, _Goal) :-
|
|
throw(time_limit_exceeded).
|
|
|
|
run_alarm_goal(AlarmID, Goal) :-
|
|
install_alarm(AlarmID),
|
|
Goal, !.
|
|
|
|
time_limit_exceeded(_Time) :-
|
|
throw(time_limit_exceeded).
|
|
|
|
current_alarm(Time, Goal, Id, Status) :-
|
|
current_alarms(Time, Goal, Id, Status, List),
|
|
member(alarm(Time, Goal, Id, Status), List).
|
|
|
|
/*******************************
|
|
* HANDLE MESSAGES *
|
|
*******************************/
|
|
|
|
:- multifile
|
|
prolog:message/3.
|
|
|
|
prolog:message(time_limit_exceeded) -->
|
|
[ 'Time limit exceeded' ].
|
|
|