copytool_monitor.py 文件源码

def open_fifo(self):
        try:
            os.mkfifo(self.copytool.event_fifo)
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise e

        pids = lsof(file=self.copytool.event_fifo)
        readers = set()
        writers = set()
        for pid, files in pids.items():
            for file, info in files.items():
                if 'r' in info['mode']:
                    readers.add(pid)
                if 'w' in info['mode']:
                    writers.add(pid)

        if readers:
            raise FifoReaderConflict(readers)

        self.reader_fd = os.open(self.copytool.event_fifo,
                                 os.O_RDONLY | os.O_NONBLOCK)
        copytool_log.info("Opened %s for reading" % self.copytool.event_fifo)