usb1.py 文件源码

def getPollFDList(self):
        """
        Return file descriptors to be used to poll USB events.
        You should not have to call this method, unless you are integrating
        this class with a polling mechanism.
        """
        pollfd_p_p = libusb1.libusb_get_pollfds(self.__context_p)
        if not pollfd_p_p:
            errno = get_errno()
            if errno:
                raise OSError(errno)
            else:
                # Assume not implemented
                raise NotImplementedError(
                    'Your libusb does not seem to implement pollable FDs')
        try:
            result = []
            append = result.append
            fd_index = 0
            while pollfd_p_p[fd_index]:
                append((
                    pollfd_p_p[fd_index].contents.fd,
                    pollfd_p_p[fd_index].contents.events,
                ))
                fd_index += 1
        finally:
            _free(pollfd_p_p)
        return result