Class ContextAwareThreadPoolExecutor

dask/threaded.py:39–59

Variant ThreadPoolExecutor that propagates contextvars from the submitting thread to the worker threads. With a vanilla ThreadPoolExecutor, contextvars are automatically propagated on CPython 3.14t (noGIL) if and only if they are set before the worker threads are started. This v

class ContextAwareThreadPoolExecutor(ThreadPoolExecutor):
    """Variant ThreadPoolExecutor that propagates contextvars
    from the submitting thread to the worker threads.

    With a vanilla ThreadPoolExecutor, contextvars are automatically propagated on
    CPython 3.14t (noGIL) if and only if they are set before the worker threads are
    started.
    This variant propagates contextvars on all Python interpreters and also when the
    worker threads are already warm when the variables are set in the submitting thread.

    This also affects catching warnings, which on 3.14t use contextvars.

    See Also
    --------
    https://docs.python.org/3/using/cmdline.html#envvar-PYTHON_THREAD_INHERIT_CONTEXT
    https://docs.python.org/3/using/cmdline.html#envvar-PYTHON_CONTEXT_AWARE_WARNINGS
    """

    def submit(self, fn, /, *args, **kwargs):
        ctx = contextvars.copy_context()
        return super().submit(ctx.run, fn, *args, **kwargs)


def get(