utils.py 文件源码

def _open_ipipes(wds, fifos, input_pipes):
    """
    This will attempt to open the named pipes in the set of ``fifos`` for
    writing, which will only succeed if the subprocess has opened them for
    reading already. This modifies and returns the list of write descriptors,
    the list of waiting fifo names, and the mapping back to input adapters.
    """
    for fifo in fifos.copy():
        try:
            fd = os.open(fifo, os.O_WRONLY | os.O_NONBLOCK)
            input_pipes[fd] = fifos.pop(fifo)
            wds.append(fd)
        except OSError as e:
            if e.errno != errno.ENXIO:
                raise e

    return wds, fifos, input_pipes