.. note::
    :class: sphx-glr-download-link-note

    Click :ref:`here <sphx_glr_download_auto_examples_reuseable_executor.py>` to download the full example code
.. rst-class:: sphx-glr-example-title

.. _sphx_glr_auto_examples_reuseable_executor.py:


Advanced Executor Setup
=======================

It is possible to reuse an executor even if it has a complicated setup. When
using the parameter `reuse=True`, the executor is resized if needed but the
arguments stay the same.







.. code-block:: python

    from time import sleep
    import multiprocessing as mp
    from loky import get_reusable_executor

    INITIALIZER_STATUS = "uninitialized"


    def initializer(x):
        global INITIALIZER_STATUS
        print("[{}] init".format(mp.current_process().name))
        INITIALIZER_STATUS = x


    def return_initializer_status(delay=0):
        sleep(delay)

        global INITIALIZER_STATUS
        return INITIALIZER_STATUS


    executor = get_reusable_executor(
        max_workers=2, initializer=initializer, initargs=('initialized',),
        context="loky", timeout=1000)

    assert INITIALIZER_STATUS == "uninitialized"
    executor.submit(return_initializer_status).result()
    assert executor.submit(return_initializer_status).result() == 'initialized'

    # With reuse=True, the executor use the same initializer
    executor = get_reusable_executor(max_workers=4, reuse=True)
    for x in executor.map(return_initializer_status, [.5] * 4):
        assert x == 'initialized'

    # With reuse='auto', the initializer is not used anymore as a new executor
    # is created.
    executor = get_reusable_executor(max_workers=4)
    for x in executor.map(return_initializer_status, [.1] * 4):
        assert x == 'uninitialized'

**Total running time of the script:** ( 0 minutes  1.060 seconds)


.. _sphx_glr_download_auto_examples_reuseable_executor.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example



  .. container:: sphx-glr-download

     :download:`Download Python source code: reuseable_executor.py <reuseable_executor.py>`



  .. container:: sphx-glr-download

     :download:`Download Jupyter notebook: reuseable_executor.ipynb <reuseable_executor.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.readthedocs.io>`_