_test_multiprocessing.py 文件源码

def test_unpickleable_result(self):
        from multiprocessing.pool import MaybeEncodingError
        p = multiprocessing.Pool(2)

        # Make sure we don't lose pool processes because of encoding errors.
        for iteration in range(20):

            scratchpad = [None]
            def errback(exc):
                scratchpad[0] = exc

            res = p.apply_async(unpickleable_result, error_callback=errback)
            self.assertRaises(MaybeEncodingError, res.get)
            wrapped = scratchpad[0]
            self.assertTrue(wrapped)
            self.assertIsInstance(scratchpad[0], MaybeEncodingError)
            self.assertIsNotNone(wrapped.exc)
            self.assertIsNotNone(wrapped.value)

        p.close()
        p.join()