test_os.py 文件源码

def test_fd_leak(self):
        # Since we're opening a lot of FDs, we must be careful to avoid leaks:
        # we both check that calling fwalk() a large number of times doesn't
        # yield EMFILE, and that the minimum allocated FD hasn't changed.
        minfd = os.dup(1)
        os.close(minfd)
        for i in range(256):
            for x in os.fwalk(support.TESTFN):
                pass
        newfd = os.dup(1)
        self.addCleanup(os.close, newfd)
        self.assertEqual(newfd, minfd)