________________________________________________________________________

This file is part of Logtalk <https://logtalk.org/>  
Copyright 1998-2023 Paulo Moura <pmoura@logtalk.org>  
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
________________________________________________________________________


% start by loading the loading the example:

| ?- logtalk_load(sync(loader)).
...


% slow print text

| ?- slow_print::start.
abc
123
abc
123
abc
123
abc
123
abc
...


% send three asynchronous messages whose corresponding methods perform output operations:

| ?- threaded_ignore(nasty1::io(alpha)), threaded_ignore(nasty1::io(digit)), threaded_ignore(nasty1::io(alpha)).

a0ab1bc2c3ddefef45gg6hh7ii8jkjk9
llmmnnopopqqrrsstztzyyxxwwuv
uv

Yes


% send three asynchronous messages whose corresponding methods perform database updates
% (this may or may not work, most likely will throw an exception):

| ?- threaded_ignore(nasty1::update_db(_)), threaded_ignore(nasty1::update_db(_)), threaded_ignore(nasty1::update_db(_)).

No


% the best solution is to declare predicates that need to be thread synchronized as "synchronized",
% as exemplified in object "nasty2":

| ?- threaded_ignore(nasty2::io(alpha)), threaded_ignore(nasty2::io(digit)), threaded_ignore(nasty2::io(alpha)).

abcdefghijklmnopqrstzyxwuv
0123456789
abcdefghijklmnopqrstzyxwuv

Yes


| ?- threaded_call(nasty2::update_db(_)), threaded_call(nasty2::update_db(_)), threaded_call(nasty2::update_db(_)).

Yes

| ?- threaded_exit(nasty2::update_db(X)), threaded_exit(nasty2::update_db(Y)), threaded_exit(nasty2::update_db(Z)).


X = 1
Y = 2
Z = 3 

Yes
