lenskit.parallel.AccelTask
==========================

.. py:class:: lenskit.parallel.AccelTask[R]
   :canonical: lenskit.parallel._task.AccelTask

   Bases: :py:obj:`Protocol`


   An accelerated task, implemented by the accelerator backend.

   This protocol is implemented by long-running accelerator tasks, and is used
   by :func:`run_accel_task` to run these tasks with cancellation, progress
   reporting, and suitable thread pool management.

   The runner will spawn a background thread and call the task's :meth:`invoke`
   method in that thread.  The main thread will poll for completion and
   progress reports.


   .. py:method:: invoke()

      Run this task and return its result.  Must only be called once for a
      given accelerator task.  Will be run on the offloaded execution thread.



   .. py:method:: cancel()

      Cancel this task.

      .. note::

          Will usually **not** be called from the same thread as
          :meth:`invoke`.



   .. py:method:: current_progress()

      Poll the current progress of this task.

      .. note::

          Will usually **not** be called from the same thread as
          :meth:`invoke`.