Let's make test_fd_transfer_windows a bit less hangy by polling for up to 60 seconds instead of simply trying to recv() and by terminating before trying to join().

    @unittest.skipUnless(HAS_REDUCTION, "test needs multiprocessing.reduction")
    @unittest.skipIf(sys.platform != "win32", "Windows-only test")
    def test_fd_transfer_windows(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)
        p = self.Process(target=self._check_handle_access, args=(child_conn,))
        p.daemon = True
        p.start()
        try:
            with open(test.support.TESTFN, "wb") as f:
                self.addCleanup(test.support.unlink, test.support.TESTFN)
                handle = msvcrt.get_osfhandle(f.fileno())
                parent_access = get_handle_info(handle).GrantedAccess
                reduction.send_handle(conn, handle, p.pid)
                if not conn.poll(timeout=60):
                    raise AssertionError("could not receive from child process")
                child_access = conn.recv()
                self.assertEqual(parent_access, child_access)
        finally:
            p.terminate()
            p.join()