pidfile.py 文件源码

def validate(self):
        """ Validate pidfile and make it stale if needed"""
        if not self.fname:
            return
        try:
            with open(self.fname, "r") as f:
                try:
                    wpid = int(f.read())
                except ValueError:
                    return

                try:
                    os.kill(wpid, 0)
                    return wpid
                except OSError as e:
                    if e.args[0] == errno.EPERM:
                        return wpid
                    if e.args[0] == errno.ESRCH:
                        return
                    raise
        except IOError as e:
            if e.args[0] == errno.ENOENT:
                return
            raise