.. This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2024 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.

.. rst-class:: align-right

built-in predicate

.. index:: pair: threaded_cancel/1; Built-in predicate .. _predicates_threaded_cancel_1:

threaded_cancel/1

Description

::

threaded_cancel(Tag)

Cancels a tagged threaded call. When there is no asynchronous call with the given tag, calling this predicate succeeds assuming the asynchronous call has already terminated or canceled. The threaded call identifier tag is generated by calls to the :ref:`threaded_call/2 <predicates_threaded_call_1_2>` and :ref:`threaded_once/2 <predicates_threaded_once_1_2>` predicates. Tags shall be regarded as an opaque term; users shall not rely on their type.

.. note::

This predicate requires a :term:`backend Prolog compiler` providing compatible multi-threading primitives. The value of the read-only :ref:`threads <flag_threads>` flag is set to supported when that is the case.

Modes and number of proofs

::

threaded_cancel(+nonvar) - one

Errors

| Tag is a variable: | instantiation_error

Examples

(none)

.. seealso::

:ref:predicates_threaded_call_1_2, :ref:predicates_threaded_exit_1_2, :ref:predicates_threaded_ignore_1, :ref:predicates_threaded_once_1_2, :ref:predicates_threaded_1