How to use the billiard.compat.isblocking function in billiard

def create_process_queues(self):
        """Creates new in, out (and optionally syn) queues,
        returned as a tuple."""
        # NOTE: Pipes must be set O_NONBLOCK at creation time (the original
        # fd), otherwise it will not be possible to change the flags until
        # there is an actual reader/writer on the other side.
        inq = _SimpleQueue(wnonblock=True)
        outq = _SimpleQueue(rnonblock=True)
        synq = None
        assert isblocking(inq._reader)
        assert not isblocking(inq._writer)
        assert not isblocking(outq._reader)
        assert isblocking(outq._writer)
        if self.synack:
            synq = _SimpleQueue(wnonblock=True)
            assert isblocking(synq._reader)
            assert not isblocking(synq._writer)
        return inq, outq, synq

# receive jobs in the old buffer, so we need to reset the
            # job._write_to and job._scheduled_for attributes used to recover
            # message boundaries when processes exit.
            infd = proc.inqW_fd
            for job in values(cache):
                if job._write_to and job._write_to.inqW_fd == infd:
                    job._write_to = proc
                if job._scheduled_for and job._scheduled_for.inqW_fd == infd:
                    job._scheduled_for = proc
            fileno_to_outq[proc.outqR_fd] = proc
            # maintain_pool is called whenever a process exits.
            add_reader(
                proc.sentinel, event_process_exit, hub, proc.sentinel,
            )

            assert not isblocking(proc.outq._reader)

            # handle_result_event is called when the processes outqueue is
            # readable.
            add_reader(proc.outqR_fd, handle_result_event, proc.outqR_fd)

            waiting_to_start.add(proc)
            hub.call_later(
                self._proc_alive_timeout, verify_process_alive, proc,
            )

def create_process_queues(self):
        """Creates new in, out (and optionally syn) queues,
        returned as a tuple."""
        # NOTE: Pipes must be set O_NONBLOCK at creation time (the original
        # fd), otherwise it will not be possible to change the flags until
        # there is an actual reader/writer on the other side.
        inq = _SimpleQueue(wnonblock=True)
        outq = _SimpleQueue(rnonblock=True)
        synq = None
        assert isblocking(inq._reader)
        assert not isblocking(inq._writer)
        assert not isblocking(outq._reader)
        assert isblocking(outq._writer)
        if self.synack:
            synq = _SimpleQueue(wnonblock=True)
            assert isblocking(synq._reader)
            assert not isblocking(synq._writer)
        return inq, outq, synq

def create_process_queues(self):
        """Create new in, out, etc. queues, returned as a tuple."""
        # NOTE: Pipes must be set O_NONBLOCK at creation time (the original
        # fd), otherwise it won't be possible to change the flags until
        # there's an actual reader/writer on the other side.
        inq = _SimpleQueue(wnonblock=True)
        outq = _SimpleQueue(rnonblock=True)
        synq = None
        assert isblocking(inq._reader)
        assert not isblocking(inq._writer)
        assert not isblocking(outq._reader)
        assert isblocking(outq._writer)
        if self.synack:
            synq = _SimpleQueue(wnonblock=True)
            assert isblocking(synq._reader)
            assert not isblocking(synq._writer)
        return inq, outq, synq

# If we got the same fd as a previous process then we'll also
            # receive jobs in the old buffer, so we need to reset the
            # job._write_to and job._scheduled_for attributes used to recover
            # message boundaries when processes exit.
            infd = proc.inqW_fd
            for job in values(cache):
                if job._write_to and job._write_to.inqW_fd == infd:
                    job._write_to = proc
                if job._scheduled_for and job._scheduled_for.inqW_fd == infd:
                    job._scheduled_for = proc
            fileno_to_outq[proc.outqR_fd] = proc

            # maintain_pool is called whenever a process exits.
            self._track_child_process(proc, hub)

            assert not isblocking(proc.outq._reader)

            # handle_result_event is called when the processes outqueue is
            # readable.
            add_reader(proc.outqR_fd, handle_result_event, proc.outqR_fd)

            waiting_to_start.add(proc)
            hub.call_later(
                self._proc_alive_timeout, verify_process_alive, ref(proc),
            )

def _recv_message(self, add_reader, fd, callback,
                      __read__=__read__, readcanbuf=readcanbuf,
                      BytesIO=BytesIO, unpack_from=unpack_from,
                      load=_pickle.load):
        Hr = Br = 0
        if readcanbuf:
            buf = bytearray(4)
            bufv = memoryview(buf)
        else:
            buf = bufv = BytesIO()
        # header
        assert not isblocking(fd)

        while Hr < 4:
            try:
                n = __read__(
                    fd, bufv[Hr:] if readcanbuf else bufv, 4 - Hr,
                )
            except OSError as exc:
                if get_errno(exc) not in UNAVAIL:
                    raise
                yield
            else:
                if n == 0:
                    raise (OSError('End of file during message') if Hr
                           else EOFError())
                Hr += n

def create_process_queues(self):
        """Creates new in, out (and optionally syn) queues,
        returned as a tuple."""
        # NOTE: Pipes must be set O_NONBLOCK at creation time (the original
        # fd), otherwise it will not be possible to change the flags until
        # there is an actual reader/writer on the other side.
        inq = _SimpleQueue(wnonblock=True)
        outq = _SimpleQueue(rnonblock=True)
        synq = None
        assert isblocking(inq._reader)
        assert not isblocking(inq._writer)
        assert not isblocking(outq._reader)
        assert isblocking(outq._writer)
        if self.synack:
            synq = _SimpleQueue(wnonblock=True)
            assert isblocking(synq._reader)
            assert not isblocking(synq._writer)
        return inq, outq, synq

"""Creates new in, out (and optionally syn) queues,
        returned as a tuple."""
        # NOTE: Pipes must be set O_NONBLOCK at creation time (the original
        # fd), otherwise it will not be possible to change the flags until
        # there is an actual reader/writer on the other side.
        inq = _SimpleQueue(wnonblock=True)
        outq = _SimpleQueue(rnonblock=True)
        synq = None
        assert isblocking(inq._reader)
        assert not isblocking(inq._writer)
        assert not isblocking(outq._reader)
        assert isblocking(outq._writer)
        if self.synack:
            synq = _SimpleQueue(wnonblock=True)
            assert isblocking(synq._reader)
            assert not isblocking(synq._writer)
        return inq, outq, synq

def create_process_queues(self):
        """Creates new in, out (and optionally syn) queues,
        returned as a tuple."""
        # NOTE: Pipes must be set O_NONBLOCK at creation time (the original
        # fd), otherwise it will not be possible to change the flags until
        # there is an actual reader/writer on the other side.
        inq = _SimpleQueue(wnonblock=True)
        outq = _SimpleQueue(rnonblock=True)
        synq = None
        assert isblocking(inq._reader)
        assert not isblocking(inq._writer)
        assert not isblocking(outq._reader)
        assert isblocking(outq._writer)
        if self.synack:
            synq = _SimpleQueue(wnonblock=True)
            assert isblocking(synq._reader)
            assert not isblocking(synq._writer)
        return inq, outq, synq