Method test_loop_access

numpy/core/tests/test_ufunc.py:2926–2966

(self)

    @pytest.mark.skipif(not hasattr(ct, "pythonapi"),
            reason="`ctypes.pythonapi` required for capsule unpacking.")
    def test_loop_access(self):
        # This is a basic test for the full strided loop access
        data_t = ct.ARRAY(ct.c_char_p, 2)
        dim_t = ct.ARRAY(ct.c_ssize_t, 1)
        strides_t = ct.ARRAY(ct.c_ssize_t, 2)
        strided_loop_t = ct.CFUNCTYPE(
                ct.c_int, ct.c_void_p, data_t, dim_t, strides_t, ct.c_void_p)

        class call_info_t(ct.Structure):
            _fields_ = [
                ("strided_loop", strided_loop_t),
                ("context", ct.c_void_p),
                ("auxdata", ct.c_void_p),
                ("requires_pyapi", ct.c_byte),
                ("no_floatingpoint_errors", ct.c_byte),
            ]

        i4 = np.dtype("i4")
        dt, call_info_obj = np.negative._resolve_dtypes_and_context((i4, i4))
        assert dt == (i4, i4)  # can be used without casting

        # Fill in the rest of the information:
        np.negative._get_strided_loop(call_info_obj)

        ct.pythonapi.PyCapsule_GetPointer.restype = ct.c_void_p
        call_info = ct.pythonapi.PyCapsule_GetPointer(
                ct.py_object(call_info_obj),
                ct.c_char_p(b"numpy_1.24_ufunc_call_info"))

        call_info = ct.cast(call_info, ct.POINTER(call_info_t)).contents

        arr = np.arange(10, dtype=i4)
        call_info.strided_loop(
                call_info.context,
                data_t(arr.ctypes.data, arr.ctypes.data),
                arr.ctypes.shape,  # is a C-array with 10 here
                strides_t(arr.ctypes.strides[0], arr.ctypes.strides[0]),
                call_info.auxdata)

        # We just directly called the negative inner-loop in-place:
        assert_array_equal(arr, -np.arange(10, dtype=i4))

    @pytest.mark.parametrize("strides", [1, (1, 2, 3), (1, "2")])
    def test__get_strided_loop_errors_bad_strides(self, strides):