subprocess.py 文件源码

def wait(self, timeout=None, check_interval=0.01):
        # Instead of a blocking OS call, this version of wait() uses logic
        # borrowed from the eventlet 0.2 processes.Process.wait() method.
        if timeout is not None:
            endtime = time.time() + timeout
        try:
            while True:
                status = self.poll()
                if status is not None:
                    return status
                if timeout is not None and time.time() > endtime:
                    raise TimeoutExpired(self.args, timeout)
                eventlet.sleep(check_interval)
        except OSError as e:
            if e.errno == errno.ECHILD:
                # no child process, this happens if the child process
                # already died and has been cleaned up
                return -1
            else:
                raise