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   SPDX-FileCopyrightText: 1998-2024 Paulo Moura <pmoura@logtalk.org>
   SPDX-License-Identifier: Apache-2.0

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   you may not use this file except in compliance with the License.
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.. rst-class:: align-right

**built-in predicate**

.. index:: pair: threaded_wait/1; Built-in predicate
.. _predicates_threaded_wait_1:

``threaded_wait/1``
===================

Description
-----------

::

   threaded_wait(Term)
   threaded_wait([Term| Terms])

Suspends the thread making the call until a notification is received
that unifies with ``Term``. The call must be made within the same object
(:term:`this`) containing the calls to the
:ref:`predicates_threaded_notify_1` predicate that will
eventually send the notification. The argument may also be a list of
notifications, ``[Term| Terms]``. In this case, the thread making the
call will suspend until all notifications in the list are received.

.. 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_wait(?term) - one
   threaded_wait(+list(term)) - one

Errors
------

(none)

Examples
--------

::

   % wait until the "data_available" notification is received:
   ..., threaded_wait(data_available), ...

.. seealso::

   :ref:`predicates_threaded_notify_1`
