test_subprocess.py 文件源码

def test_pass_fds_inheritable(self):
        script = support.findfile("fd_status.py", subdir="subprocessdata")

        inheritable, non_inheritable = os.pipe()
        self.addCleanup(os.close, inheritable)
        self.addCleanup(os.close, non_inheritable)
        os.set_inheritable(inheritable, True)
        os.set_inheritable(non_inheritable, False)
        pass_fds = (inheritable, non_inheritable)
        args = [sys.executable, script]
        args += list(map(str, pass_fds))

        p = subprocess.Popen(args,
                             stdout=subprocess.PIPE, close_fds=True,
                             pass_fds=pass_fds)
        output, ignored = p.communicate()
        fds = set(map(int, output.split(b',')))

        # the inheritable file descriptor must be inherited, so its inheritable
        # flag must be set in the child process after fork() and before exec()
        self.assertEqual(fds, set(pass_fds), "output=%a" % output)

        # inheritable flag must not be changed in the parent process
        self.assertEqual(os.get_inheritable(inheritable), True)
        self.assertEqual(os.get_inheritable(non_inheritable), False)