test_multiprocessing.py 文件源码

def test_access(self):
        # On Windows, if we do not specify a destination pid when
        # using DupHandle then we need to be careful to use the
        # correct access flags for DuplicateHandle(), or else
        # DupHandle.detach() will raise PermissionError.  For example,
        # for a read only pipe handle we should use
        # access=FILE_GENERIC_READ.  (Unfortunately
        # DUPLICATE_SAME_ACCESS does not work.)
        conn, child_conn = self.Pipe()
        p = self.Process(target=self.child_access, args=(child_conn,))
        p.daemon = True
        p.start()
        child_conn.close()

        r, w = self.Pipe(duplex=False)
        conn.send(w)
        w.close()
        self.assertEqual(r.recv(), 'all is well')
        r.close()

        r, w = self.Pipe(duplex=False)
        conn.send(r)
        r.close()
        w.send('foobar')
        w.close()
        self.assertEqual(conn.recv(), 'foobar'*2)

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