Source code for traits_futures.multithreading_context

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#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
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"""
Context providing multithreading-friendly worker pools, events, and routers.
"""

import concurrent.futures
import threading

from traits_futures.i_parallel_context import IParallelContext
from traits_futures.multithreading_router import MultithreadingRouter




class MultithreadingContext(IParallelContext):
    """
    Context for multithreading, suitable for use with the TraitsExecutor.
    """

    def __init__(self):
        self._closed = False



    def worker_pool(self, *, max_workers=None):
        """
        Provide a new worker pool suitable for this context.

        Parameters
        ----------
        max_workers : int, optional
            Maximum number of workers to use. If not given, the choice is
            delegated to the ThreadPoolExecutor.

        Returns
        -------
        executor : concurrent.futures.Executor
        """
        return concurrent.futures.ThreadPoolExecutor(max_workers=max_workers)




    def event(self):
        """
        Return a shareable event suitable for this context.

        Returns
        -------
        event : object
            An event that can be shared safely with workers.
            The event should have the same API as :class:`threading.Event`
            and :class:`multiprocessing.Event`, providing at a minimum
            the ``set`` and ``is_set`` methods from that API.
        """
        return threading.Event()




    def message_router(self, event_loop):
        """
        Return a message router suitable for use in this context.

        Parameters
        ----------
        event_loop : IEventLoop
            The event loop used to trigger message dispatch.

        Returns
        -------
        message_router : MultithreadingRouter
        """
        return MultithreadingRouter(event_loop=event_loop)




    def close(self):
        """
        Do any cleanup necessary before disposal of the context.
        """
        self._closed = True


    @property
    def closed(self):
        """
        True if this context is closed, else False.
        """
        return self._closed