python – 龙卷风中断系统调用

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/tornado/ioloop.py",line 662,in start
    event_pairs = self._impl.poll(poll_timeout)
IOError: [Errno 4] Interrupted system call

有谁知道这意味着什么/什么时候发生？

我正在使用python 2.7和tornado 3.2.1

更新：此代码位于ioloop.py中

try:
    event_pairs = self._impl.poll(poll_timeout)
except Exception as e:
    # Depending on python version and IOLoop implementation,# different exception types may be thrown and there are
    # two ways EINTR might be signaled:
    # * e.errno == errno.EINTR
    # * e.args is like (errno.EINTR,'Interrupted system call')
    if (getattr(e,'errno',None) == errno.EINTR or
          (isinstance(getattr(e,'args',None),tuple) and
          len(e.args) == 2 and e.args[0] == errno.EINTR)):
        continue
    else:
        raise