398 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Prolog
		
	
	
	
	
	
			
		
		
	
	
			398 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Prolog
		
	
	
	
	
	
| %%% -*- Mode: Prolog; -*-
 | |
| 
 | |
| %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | |
| %
 | |
| %  Concurrent alarms was developed at Katholieke Universiteit Leuven
 | |
| %
 | |
| %  Copyright 2010
 | |
| %  Katholieke Universiteit Leuven
 | |
| %
 | |
| %  Contributions to this file:
 | |
| %  Author: Theofrastos Mantadelis
 | |
| %  $Date: 2011-02-04 16:04:49 +0100 (Fri, 04 Feb 2011) $
 | |
| %  $Revision: 11 $
 | |
| %  Contributions: The timer implementation is inspired by Bernd Gutmann's timers
 | |
| %
 | |
| %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | |
| %
 | |
| % Artistic License 2.0
 | |
| %
 | |
| % Copyright (c) 2000-2006, The Perl Foundation.
 | |
| %
 | |
| % Everyone is permitted to copy and distribute verbatim copies of this
 | |
| % license document, but changing it is not allowed.  Preamble
 | |
| %
 | |
| % This license establishes the terms under which a given free software
 | |
| % Package may be copied, modified, distributed, and/or
 | |
| % redistributed. The intent is that the Copyright Holder maintains some
 | |
| % artistic control over the development of that Package while still
 | |
| % keeping the Package available as open source and free software.
 | |
| %
 | |
| % You are always permitted to make arrangements wholly outside of this
 | |
| % license directly with the Copyright Holder of a given Package. If the
 | |
| % terms of this license do not permit the full use that you propose to
 | |
| % make of the Package, you should contact the Copyright Holder and seek
 | |
| % a different licensing arrangement.  Definitions
 | |
| %
 | |
| % "Copyright Holder" means the individual(s) or organization(s) named in
 | |
| % the copyright notice for the entire Package.
 | |
| %
 | |
| % "Contributor" means any party that has contributed code or other
 | |
| % material to the Package, in accordance with the Copyright Holder's
 | |
| % procedures.
 | |
| %
 | |
| % "You" and "your" means any person who would like to copy, distribute,
 | |
| % or modify the Package.
 | |
| %
 | |
| % "Package" means the collection of files distributed by the Copyright
 | |
| % Holder, and derivatives of that collection and/or of those files. A
 | |
| % given Package may consist of either the Standard Version, or a
 | |
| % Modified Version.
 | |
| %
 | |
| % "Distribute" means providing a copy of the Package or making it
 | |
| % accessible to anyone else, or in the case of a company or
 | |
| % organization, to others outside of your company or organization.
 | |
| %
 | |
| % "Distributor Fee" means any fee that you charge for Distributing this
 | |
| % Package or providing support for this Package to another party. It
 | |
| % does not mean licensing fees.
 | |
| %
 | |
| % "Standard Version" refers to the Package if it has not been modified,
 | |
| % or has been modified only in ways explicitly requested by the
 | |
| % Copyright Holder.
 | |
| %
 | |
| % "Modified Version" means the Package, if it has been changed, and such
 | |
| % changes were not explicitly requested by the Copyright Holder.
 | |
| %
 | |
| % "Original License" means this Artistic License as Distributed with the
 | |
| % Standard Version of the Package, in its current version or as it may
 | |
| % be modified by The Perl Foundation in the future.
 | |
| %
 | |
| % "Source" form means the source code, documentation source, and
 | |
| % configuration files for the Package.
 | |
| %
 | |
| % "Compiled" form means the compiled bytecode, object code, binary, or
 | |
| % any other form resulting from mechanical transformation or translation
 | |
| % of the Source form.
 | |
| %
 | |
| %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | |
| %
 | |
| % Permission for Use and Modification Without Distribution
 | |
| %
 | |
| % (1) You are permitted to use the Standard Version and create and use
 | |
| % Modified Versions for any purpose without restriction, provided that
 | |
| % you do not Distribute the Modified Version.
 | |
| %
 | |
| % Permissions for Redistribution of the Standard Version
 | |
| %
 | |
| % (2) You may Distribute verbatim copies of the Source form of the
 | |
| % Standard Version of this Package in any medium without restriction,
 | |
| % either gratis or for a Distributor Fee, provided that you duplicate
 | |
| % all of the original copyright notices and associated disclaimers. At
 | |
| % your discretion, such verbatim copies may or may not include a
 | |
| % Compiled form of the Package.
 | |
| %
 | |
| % (3) You may apply any bug fixes, portability changes, and other
 | |
| % modifications made available from the Copyright Holder. The resulting
 | |
| % Package will still be considered the Standard Version, and as such
 | |
| % will be subject to the Original License.
 | |
| %
 | |
| % Distribution of Modified Versions of the Package as Source
 | |
| %
 | |
| % (4) You may Distribute your Modified Version as Source (either gratis
 | |
| % or for a Distributor Fee, and with or without a Compiled form of the
 | |
| % Modified Version) provided that you clearly document how it differs
 | |
| % from the Standard Version, including, but not limited to, documenting
 | |
| % any non-standard features, executables, or modules, and provided that
 | |
| % you do at least ONE of the following:
 | |
| %
 | |
| % (a) make the Modified Version available to the Copyright Holder of the
 | |
| % Standard Version, under the Original License, so that the Copyright
 | |
| % Holder may include your modifications in the Standard Version.  (b)
 | |
| % ensure that installation of your Modified Version does not prevent the
 | |
| % user installing or running the Standard Version. In addition, the
 | |
| % modified Version must bear a name that is different from the name of
 | |
| % the Standard Version.  (c) allow anyone who receives a copy of the
 | |
| % Modified Version to make the Source form of the Modified Version
 | |
| % available to others under (i) the Original License or (ii) a license
 | |
| % that permits the licensee to freely copy, modify and redistribute the
 | |
| % Modified Version using the same licensing terms that apply to the copy
 | |
| % that the licensee received, and requires that the Source form of the
 | |
| % Modified Version, and of any works derived from it, be made freely
 | |
| % available in that license fees are prohibited but Distributor Fees are
 | |
| % allowed.
 | |
| %
 | |
| % Distribution of Compiled Forms of the Standard Version or
 | |
| % Modified Versions without the Source
 | |
| %
 | |
| % (5) You may Distribute Compiled forms of the Standard Version without
 | |
| % the Source, provided that you include complete instructions on how to
 | |
| % get the Source of the Standard Version. Such instructions must be
 | |
| % valid at the time of your distribution. If these instructions, at any
 | |
| % time while you are carrying out such distribution, become invalid, you
 | |
| % must provide new instructions on demand or cease further
 | |
| % distribution. If you provide valid instructions or cease distribution
 | |
| % within thirty days after you become aware that the instructions are
 | |
| % invalid, then you do not forfeit any of your rights under this
 | |
| % license.
 | |
| %
 | |
| % (6) You may Distribute a Modified Version in Compiled form without the
 | |
| % Source, provided that you comply with Section 4 with respect to the
 | |
| % Source of the Modified Version.
 | |
| %
 | |
| % Aggregating or Linking the Package
 | |
| %
 | |
| % (7) You may aggregate the Package (either the Standard Version or
 | |
| % Modified Version) with other packages and Distribute the resulting
 | |
| % aggregation provided that you do not charge a licensing fee for the
 | |
| % Package. Distributor Fees are permitted, and licensing fees for other
 | |
| % components in the aggregation are permitted. The terms of this license
 | |
| % apply to the use and Distribution of the Standard or Modified Versions
 | |
| % as included in the aggregation.
 | |
| %
 | |
| % (8) You are permitted to link Modified and Standard Versions with
 | |
| % other works, to embed the Package in a larger work of your own, or to
 | |
| % build stand-alone binary or bytecode versions of applications that
 | |
| % include the Package, and Distribute the result without restriction,
 | |
| % provided the result does not expose a direct interface to the Package.
 | |
| %
 | |
| % Items That are Not Considered Part of a Modified Version
 | |
| %
 | |
| % (9) Works (including, but not limited to, modules and scripts) that
 | |
| % merely extend or make use of the Package, do not, by themselves, cause
 | |
| % the Package to be a Modified Version. In addition, such works are not
 | |
| % considered parts of the Package itself, and are not subject to the
 | |
| % terms of this license.
 | |
| %
 | |
| % General Provisions
 | |
| %
 | |
| % (10) Any use, modification, and distribution of the Standard or
 | |
| % Modified Versions is governed by this Artistic License. By using,
 | |
| % modifying or distributing the Package, you accept this license. Do not
 | |
| % use, modify, or distribute the Package, if you do not accept this
 | |
| % license.
 | |
| %
 | |
| % (11) If your Modified Version has been derived from a Modified Version
 | |
| % made by someone other than you, you are nevertheless required to
 | |
| % ensure that your Modified Version complies with the requirements of
 | |
| % this license.
 | |
| %
 | |
| % (12) This license does not grant you the right to use any trademark,
 | |
| % service mark, tradename, or logo of the Copyright Holder.
 | |
| %
 | |
| % (13) This license includes the non-exclusive, worldwide,
 | |
| % free-of-charge patent license to make, have made, use, offer to sell,
 | |
| % sell, import and otherwise transfer the Package with respect to any
 | |
| % patent claims licensable by the Copyright Holder that are necessarily
 | |
| % infringed by the Package. If you institute patent litigation
 | |
| % (including a cross-claim or counterclaim) against any party alleging
 | |
| % that the Package constitutes direct or contributory patent
 | |
| % infringement, then this Artistic License to you shall terminate on the
 | |
| % date that such litigation is filed.
 | |
| %
 | |
| % (14) Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT
 | |
| % HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED
 | |
| % WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 | |
| % PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT
 | |
| % PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT
 | |
| % HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT,
 | |
| % INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE
 | |
| % OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 | |
| %
 | |
| %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | |
| 
 | |
| :- module(c_alarms, [set_alarm/3,
 | |
|                      unset_alarm/1,
 | |
|                      time_out_call_once/3,
 | |
|                      timer_start/1,
 | |
|                      timer_restart/1,
 | |
|                      timer_stop/2,
 | |
|                      timer_elapsed/2,
 | |
|                      timer_pause/2]).
 | |
| 
 | |
| % set_alarm(+Seconds, +Execute, -ID)
 | |
| %   calls Executes after a time interval of Seconds
 | |
| %   ID is returned to be able to unset the alarm (the call will not be executed)
 | |
| %   set_alarm/3 supports multiple & nested settings of alarms.
 | |
| %   Known Bug: There is the case that an alarm might trigger +-1 second of the set time.
 | |
| %
 | |
| % unset_alarm(+ID)
 | |
| %   It will unschedule the alarm.
 | |
| %   It will not affect other concurrent alarms.
 | |
| %
 | |
| % time_out_call(+Seconds, +Goal, -Return)
 | |
| %   It will will execute the closure Goal and returns its success or failure at Return.
 | |
| %   If the goal times out in Seconds then Return = timeout.
 | |
| 
 | |
| :- use_module(library(lists), [member/2, memberchk/2, delete/3]).
 | |
| :- use_module(library(ordsets), [ord_add_element/3]).
 | |
| :- use_module(library(apply_macros), [maplist/3]).
 | |
| 
 | |
| :- dynamic('$timer'/3).
 | |
| 
 | |
| :- meta_predicate(set_alarm(+, 0, -)).
 | |
| :- meta_predicate(time_out_call_once(+, 0, -)).
 | |
| :- meta_predicate(prove_once(0)).
 | |
| 
 | |
| :- initialization(local_init).
 | |
| 
 | |
| local_init:-
 | |
|   bb_put(alarms, []),
 | |
|   bb_put(identity, 0).
 | |
| 
 | |
| get_next_identity(ID):-
 | |
|   bb_get(identity, ID),
 | |
|   NID is ID + 1,
 | |
|   bb_put(identity, NID).
 | |
| 
 | |
| set_alarm(Seconds, Execute, ID):-
 | |
|   bb_get(alarms, []),
 | |
|   get_next_identity(ID), !,
 | |
|   bb_put(alarms, [alarm(Seconds, ID, Execute)]),
 | |
|   alarm(Seconds, alarm_handler, _).
 | |
| set_alarm(Seconds, Execute, ID):-
 | |
|   get_next_identity(ID), !,
 | |
|   bb_get(alarms, [alarm(CurrentSeconds, CurrentID, CurrentExecute)|Alarms]),
 | |
|   alarm(0, true, Remaining),
 | |
|   Elapsed is CurrentSeconds - Remaining - 1,
 | |
|   maplist(subtract(Elapsed), [alarm(CurrentSeconds, CurrentID, CurrentExecute)|Alarms], RemainingAlarms),
 | |
|   ord_add_element(RemainingAlarms, alarm(Seconds, ID, Execute), [alarm(NewSeconds, NewID, NewToExecute)|NewAlarms]),
 | |
|   bb_put(alarms, [alarm(NewSeconds, NewID, NewToExecute)|NewAlarms]),
 | |
|   alarm(NewSeconds, alarm_handler, _).
 | |
| set_alarm(Seconds, Execute, ID):-
 | |
|   throw(error(permission_error(create, alarm, set_alarm(Seconds, Execute, ID)), 'Non permitted alarm identifier.')).
 | |
| 
 | |
| subtract(Elapsed, alarm(Seconds, ID, Execute), alarm(NewSeconds, ID, Execute)):-
 | |
|   NewSeconds is Seconds - Elapsed.
 | |
| 
 | |
| unset_alarm(ID):-
 | |
|   \+ ground(ID),
 | |
|   throw(error(instantiation_error, 'Alarm ID needs to be instantiated.')).
 | |
| unset_alarm(ID):-
 | |
|   bb_get(alarms, Alarms),
 | |
|   \+ memberchk(alarm(_Seconds, ID, _Execute), Alarms),
 | |
|   throw(error(existence_error(alarm, unset_alarm(ID)), 'Alarm does not exist.')).
 | |
| unset_alarm(ID):-
 | |
|   alarm(0, true, Remaining),
 | |
|   bb_get(alarms, Alarms),
 | |
|   [alarm(Seconds, _, _)|_] = Alarms,
 | |
|   Elapsed is Seconds - Remaining - 1,
 | |
|   delete_alarm(Alarms, ID, NewAlarms),
 | |
|   bb_put(alarms, NewAlarms),
 | |
|   (NewAlarms = [alarm(NewSeconds, _, _)|_] ->
 | |
|     RemainingSeconds is NewSeconds - Elapsed,
 | |
|     alarm(RemainingSeconds, alarm_handler, _)
 | |
|   ;
 | |
|     true
 | |
|   ).
 | |
| 
 | |
| delete_alarm(Alarms, ID, NewAlarms):-
 | |
|   memberchk(alarm(Seconds, ID, Execute), Alarms),
 | |
|   delete(Alarms, alarm(Seconds, ID, Execute), NewAlarms).
 | |
| 
 | |
| alarm_handler:-
 | |
|   bb_get(alarms, [alarm(_, _, CurrentExecute)|[]]),
 | |
|   bb_put(alarms, []),
 | |
|   call(CurrentExecute).
 | |
| alarm_handler:-
 | |
|   bb_get(alarms, [alarm(Elapsed, CurrentID, CurrentExecute)|Alarms]),
 | |
|   maplist(subtract(Elapsed), Alarms, NewAlarms),
 | |
|   find_zeros(NewAlarms, ZeroAlarms),
 | |
|   findall(alarm(S, ID, E), (member(alarm(S, ID, E), NewAlarms), S > 0), NonZeroAlarms),
 | |
|   bb_put(alarms, NonZeroAlarms),
 | |
|   (NonZeroAlarms = [alarm(NewSeconds, _, _)|_] ->
 | |
|     alarm(NewSeconds, alarm_handler, _)
 | |
|   ;
 | |
|     true
 | |
|   ),
 | |
|   execute([alarm(0, CurrentID, CurrentExecute)|ZeroAlarms]).
 | |
| 
 | |
| find_zeros([], []).
 | |
| find_zeros([alarm(0, ID, E)|T], [alarm(0, ID, E)|R]):-
 | |
|   find_zeros(T, R).
 | |
| find_zeros([alarm(S, _, _)|T], R):-
 | |
|   S > 0,
 | |
|   find_zeros(T, R).
 | |
| 
 | |
| execute([]).
 | |
| execute([alarm(_, _, Execute)|R]):-
 | |
|   call(Execute),
 | |
|   execute(R).
 | |
| 
 | |
| time_out_call_once(Seconds, Goal, Return):-
 | |
|   bb_get(identity, ID),
 | |
|   set_alarm(Seconds, throw(timeout(ID)), ID),
 | |
|   catch((
 | |
|     prove_once(Goal, Return),
 | |
|     unset_alarm(ID))
 | |
|   , Exception, (
 | |
|     (Exception == timeout(ID) ->
 | |
|       Return = timeout
 | |
|     ;
 | |
|       unset_alarm(ID),
 | |
|       throw(Exception)
 | |
|     ))).
 | |
| 
 | |
| prove_once(Goal, success):-
 | |
|   once(Goal), !.
 | |
| prove_once(_Goal, failure).
 | |
| 
 | |
| timer_start(Name):-
 | |
|   \+ ground(Name),
 | |
|   throw(error(instantiation_error, 'Timer name needs to be instantiated.')).
 | |
| timer_start(Name):-
 | |
|   '$timer'(Name, _, _),
 | |
|   throw(error(permission_error(create, timer, timer_start(Name)), 'Timer already exists.')).
 | |
| timer_start(Name):-
 | |
|   statistics(walltime, [StartTime, _]),
 | |
|   assertz('$timer'(Name, running, StartTime)).
 | |
| 
 | |
| timer_restart(Name):-
 | |
|   \+ ground(Name),
 | |
|   throw(error(instantiation_error, 'Timer name needs to be instantiated.')).
 | |
| timer_restart(Name):-
 | |
|   \+ '$timer'(Name, _, _), !,
 | |
|   statistics(walltime, [StartTime, _]),
 | |
|   assertz('$timer'(Name, running, StartTime)).
 | |
| timer_restart(Name):-
 | |
|   retract('$timer'(Name, running, _)), !,
 | |
|   statistics(walltime, [StartTime, _]),
 | |
|   assertz('$timer'(Name, running, StartTime)).
 | |
| timer_restart(Name):-
 | |
|   retract('$timer'(Name, paused, Duration)),
 | |
|   statistics(walltime, [StartTime, _]),
 | |
|   Elapsed is StartTime - Duration,
 | |
|   assertz('$timer'(Name, running, Elapsed)).
 | |
| 
 | |
| timer_stop(Name, Elapsed):-
 | |
|   \+ '$timer'(Name, _, _),
 | |
|   throw(error(existence_error(timer, timer_stop(Name, Elapsed)), 'Timer does not exist.')).
 | |
| timer_stop(Name, Elapsed):-
 | |
|   retract('$timer'(Name, running, StartTime)), !,
 | |
|   statistics(walltime, [EndTime, _]),
 | |
|   Elapsed is EndTime - StartTime.
 | |
| timer_stop(Name, Elapsed):-
 | |
|   retract('$timer'(Name, paused, Elapsed)).
 | |
| 
 | |
| timer_elapsed(Name, Elapsed):-
 | |
|   \+ '$timer'(Name, _, _),
 | |
|   throw(error(existence_error(timer, timer_elapsed(Name, Elapsed)), 'Timer does not exist.')).
 | |
| timer_elapsed(Name, Elapsed):-
 | |
|   '$timer'(Name, running, StartTime), !,
 | |
|   statistics(walltime, [EndTime, _]),
 | |
|   Elapsed is EndTime - StartTime.
 | |
| timer_elapsed(Name, Elapsed):-
 | |
|   '$timer'(Name, paused, Elapsed).
 | |
| 
 | |
| timer_pause(Name, Elapsed):-
 | |
|   \+ '$timer'(Name, _, _),
 | |
|   throw(error(existence_error(timer, timer_pause(Name, Elapsed)), 'Timer does not exist.')).
 | |
| timer_pause(Name, Elapsed):-
 | |
|   '$timer'(Name, paused, _),
 | |
|   throw(error(permission_error(timer, timer_pause(Name, Elapsed)), 'Timer already paused.')).
 | |
| timer_pause(Name, Elapsed):-
 | |
|   retract('$timer'(Name, _, StartTime)),
 | |
|   statistics(walltime, [EndTime, _]),
 | |
|   Elapsed is EndTime - StartTime,
 | |
|   assertz('$timer'(Name, paused, Elapsed)).
 |