.. index::
    double: barrier; algorithms
    double: barrier; plugins

Barrier algorithms
==================

Usage
-----

| *Description:* Selects the barrier algorithm used during the execution.
| *Type:* string value.
| *Environment variable:* ``NX_BARRIER=<string>``
| *Command line flag:* ``--barrier[ |=]<string>``

List of barrier plugins
-----------------------

.. index::
    double: barrier; centralized

Centralized
^^^^^^^^^^^

.. important::
    This is the default barrier algorithm

* *Configuratin string:* ``NX_BARRIER=centralized`` *or* ``NX_ARGS="--barrier=centralized``
* *Description:* All the threads are synchronized following a centralized structure.

.. index::
    double: barrier; tree

Tree
^^^^

.. warning::
    This barrier is experimental.

* *Configuration string:* ``NX_BARRIER=tree`` *or* ``NX_ARGS="--barrier=tree"``
* *Description:* Threads are synchronized following a tree structure.