Function test_refcounting_futures

dask/tests/test_expr.py:122–144

()

@pytest.mark.slow()
def test_refcounting_futures():
    pd = pytest.importorskip("pandas")
    dd = pytest.importorskip("dask.dataframe")
    distributed = pytest.importorskip("distributed")

    # See https://github.com/dask/distributed/issues/9041
    # Didn't reproduce with any of our fixtures
    with distributed.Client(
        n_workers=2, worker_class=distributed.Worker, dashboard_address=":0"
    ) as client:

        def gen(i):
            return pd.DataFrame({"A": [i]}, index=[i])

        futures = [client.submit(gen, i) for i in range(3)]

        meta = gen(0)[:0]
        df = dd.from_delayed(futures, meta)
        df.compute()

        del futures

        df.compute()


class FooExpr(Expr):